JP2007088366A - Chip resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip resistor suitable as the chip resistor for high electric power in which cooling efficiency can be enhanced when packaged in a printed circuit board (particularly, metal substrate), and withstand voltage is made to be high by lengthening insulation distance. <P>SOLUTION: In the chip resistor A1; the resistor 70 prepared between a pair of electrodes 20 is provided with high exoergic portions H1, H2, and a low exoergic portion L being connected in series, and a soldering side is formed in the undersurface region corresponding to the high exoergic portions H1, H2. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a chip resistor, and more particularly to a square chip resistor suitable for high power use.

  In recent years, various devices such as air conditioners, inverters, automobiles, and communication devices have been reduced in size, increased integration, and increased in power, and so-called high-power printed boards used in such devices are so-called. There is a metal substrate base printed circuit board (hereinafter referred to as “metal substrate”). This metal substrate is composed of an aluminum plate, an insulating layer having high thermal conductivity provided on the aluminum plate, and a conductor foil (specifically, copper foil) provided on the insulating layer, and is made of alumina. This is a highly thermally conductive metal substrate that is surface mountable and has a thermal resistance equivalent to or lower than that of a ceramic substrate. Since this metal substrate has good thermal conductivity, it is possible to effectively cool the heat generated by the electronic component surface-mounted on the conductor foil surface by attaching the aluminum base side to the heat radiation fin.

  In the chip resistor mounted on the metal substrate as described above, since the power consumption is limited by the heat generated by the voltage and current applied to the chip resistor, it is necessary to cool the chip resistor as much as possible. The substrate in the chip resistor is made of alumina ceramic having high thermal conductivity and soldered to the metal substrate through the electrode of the chip resistor to cool the heat generated by the chip resistor.

  However, since the heat generated by the entire chip resistor is dissipated by heat conduction from the small electrode portion, the temperature of the center portion of the chip resistor rises and reaches the limit when the power consumption increases. In particular, when a chip resistor is soldered to a metal substrate, the electrode portion is sufficiently cooled, but the center portion of the chip resistor is separated from the electrode, so it is difficult to cool, and the effect of using the metal substrate is demonstrated so much There was a problem that I could not.

  As a conventional chip resistor for dealing with such problems, as shown in FIG. 13, aluminum nitride having high thermal conductivity is used for the chip resistor substrate, and the soldering surface on the back surface is made as wide as possible. Some attempt to improve the cooling effect.

Moreover, the applicant knows patent document 1 and patent document 2 as prior art documents. In particular, in Patent Document 2, as a conventional example, FIG. 3 discloses a chip resistor in which a good heat conductive film is provided on the lower surface of an insulating substrate and a heat dissipation measure is taken.
Japanese Patent Laid-Open No. 9-162002 JP-A-7-176411

  However, in the first example, the third example, and the fourth example of FIG. 13, the electrode of the chip resistor is also provided widely on the lower surface of the substrate, the soldering surface is provided wider, and the contact area with the metal substrate is increased. Thus, although it is intended to promote cooling, there is a drawback that the insulation distance α is shortened and the withstand voltage is low. If the withstand voltage is low, it is not suitable for a chip resistor for high power. Further, in the second example of FIG. 13, since the electrodes are provided only on both sides of the lower surface of the substrate, there is a problem that heat generated near the center of the resistor cannot be dissipated.

  Further, in the chip electronic component of Patent Document 1, since the electrode (third electrode 4) is widely provided on the lower surface of the chip base, the cooling efficiency is good, but the first electrode 2 and the third electrode 4 are good. Since the distance between and is short, the insulation distance is short and the withstand voltage is low.

  Moreover, about the prior art example of patent document 2, although the cooling efficiency is good by providing the good heat conductive film, since the distance between both ends of the good heat conductive film and the electrode is short, the insulation distance is short, There is a disadvantage that withstand voltage is low.

  Therefore, the problem to be solved by the present invention is that when mounted on a printed circuit board (especially a metal substrate), the cooling efficiency can be increased, and the insulation distance is increased to increase the withstand voltage, A chip resistor suitable as a power chip resistor is provided.

  The present invention has been created to solve the above problems. First, the chip resistor is an insulating substrate, a pair of electrode portions provided on the insulating substrate, and the pair of electrodes. The resistor is provided so as to connect the electrode portions of the high heat generating portion and the low heat generating portion connected in series, and the high heat generating portion is provided closer to the electrode portion than the low heat generating portion. The electrode portion is formed up to at least a part of a lower surface side region corresponding to the region of the high heat generating portion in the insulating substrate.

  In the chip resistor having the first configuration, the high heat generation portion and the low heat generation portion are provided in series, and the high heat generation portion is provided closer to the electrode portion than the low heat generation portion, and is insulated. Since the electrode part is formed up to at least a part of the area on the lower surface side corresponding to the area of the high heat generating part in the substrate, the heat generated from the high heat generating part is easily radiated from the electrode part, Since the heat generation is small, the heat dissipation efficiency of the entire chip resistor can be increased. In addition, since a sufficient distance can be secured between the two electrode portions, the withstand voltage can be increased by increasing the insulation distance. Further, the high heat generating portion is provided closer to the electrode portion than the low heat generating portion, and the electrode portion extends to at least a part of the lower surface side region corresponding to the region of the high heat generating portion in the insulating substrate. Since it is formed, the heat generated from the high heat-generating portion is easily radiated from the electrode portion, and the thinner the insulating substrate, the better the heat dissipation efficiency to the metal substrate, and thus the insulating substrate can be made thinner. As described above, a chip resistor suitable as a high-power chip resistor can be provided.

  The second is a chip resistor, which is an insulating substrate, a pair of electrode portions provided on the insulating substrate, and a resistor provided so as to connect the pair of electrode portions. And a resistor provided in series with the low heat generation portion, and at least a part of the lower surface side region corresponding to the region of the high heat generation portion in the insulating substrate is a soldering surface Is formed.

  In the chip resistor having the second configuration, the high heat generating portion and the low heat generating portion are connected in series, and at least a part of the lower surface side region corresponding to the region of the high heat generating portion in the insulating substrate. Since the soldering surface is formed, the heat generated from the high heat generation part is easily radiated from the soldering surface in at least a part of the region directly under the high heat generation part, and the heat dissipation efficiency of the entire chip resistor is improved. Can be high. In addition, since the heat generation from the low heat generating portion is small, it is not necessary to provide a soldering surface in the region immediately below the low heat generating portion, so that a sufficient insulation distance can be secured and the withstand voltage can be increased. In addition, since the soldering surface is formed on at least a part of the lower surface side region corresponding to the region of the high heat generating portion in the insulating substrate, the heat generated from the high heat generating portion is dissipated from the soldering surface. Therefore, it is easier to reduce the heat dissipation efficiency to the metal substrate by reducing the thickness of the insulating substrate, and therefore the insulating substrate can be made thinner. As described above, a chip resistor suitable as a high-power chip resistor can be provided.

  Thirdly, in the second configuration, the high heat generating portion is provided closer to the upper surface electrode than the low heat generating portion.

  Fourthly, in the second or third configuration, the soldering surface is formed as a part of the electrode portion.

  According to a fifth aspect of the present invention, in any one of the first to fourth configurations, the high heat generating portion of the resistor is formed by forming a part of the resistor in a lattice shape. And By forming a trimming groove so as to cut a strip-shaped portion that forms a lattice shape by forming a part of the resistor in a lattice shape in this way, cracks are less likely to occur in the resistor, and a low noise chip Can provide resistors. Further, by forming the plurality of trimming grooves in a dispersed manner, it is possible to make the heat generation in the lattice-like high heat generating portion uniform.

  Sixth, in any one of the first to fifth configurations, the high heat generating portion of the resistor is formed by forming the resistor in a slit shape.

  Seventhly, in any one of the first to sixth configurations, the high heat generating portion in the resistor is formed by making the width of the resistance path narrower than the low heat generating portion. Features.

  Eighthly, in the seventh configuration, the high heat generation portion is formed in a meandering shape.

  Ninth, a chip resistor is an insulating substrate, a pair of lower surface electrodes formed on the lower surface of the insulating substrate, and a pair formed on the upper surface of the insulating substrate and longer than the lower surface electrode. A top surface electrode, a resistor formed between the top surface electrodes, and a protective film covering a part of the top surface electrode, wherein the width of the protective film is formed larger than the width of the top surface electrode, The upper surface electrode is a low heat generating portion, the region between the upper surface electrodes of the resistor is a high heat generating portion, and at least a part of the lower surface side region corresponding to the region of the high heat generating portion in the insulating substrate A soldering surface is formed.

  In the chip resistor of the ninth configuration, since the soldering surface is formed in at least a part of the lower surface side region corresponding to the region of the high heat generating portion, the heat generated from the high heat generating portion is high. Heat is easily radiated from the soldering surface directly under the heat generating part, and the heat dissipation efficiency of the entire chip resistor can be increased. In addition, since the heat generation from the low heat generation portion is small, it is not necessary to provide a soldering surface in at least a part of the lower surface side corresponding to the region of the low heat generation portion, and the upper surface electrode is formed longer than the lower surface electrode. Therefore, it is possible to secure a sufficient area where the soldering surface is not provided, to ensure a sufficient insulation distance, and to increase the withstand voltage. In addition, since the soldering surface is formed, the heat generated from the high heat generating portion is easily radiated from the soldering surface, and the thinner the insulating substrate, the better the heat dissipation efficiency to the metal substrate. Can be thinned. As described above, a chip resistor suitable as a high-power chip resistor can be provided.

  In each configuration described above, the “high heat generating portion” may be a “high resistance portion”, and the “low heat generating portion” may be a “low resistance portion”.

  According to the chip resistor based on the present invention, when mounted on a printed circuit board (particularly a metal substrate or an alumina ceramic substrate), the cooling efficiency can be increased, and the withstand voltage is increased by increasing the insulation distance. A chip resistor suitable as a high-power chip resistor can be provided.

  In the present invention, when mounted on a printed circuit board (in particular, a metal substrate or an alumina ceramic substrate), the cooling efficiency can be increased, and the insulation distance is increased to increase the withstand voltage, thereby increasing the power consumption. The object of providing a chip resistor suitable as a resistor was realized as follows.

  1, 3, 4, and 7 to 12, (a) shows a sectional view of the chip resistor, (b) shows a plan view, and (c) shows a bottom view. It is. Here, the sectional view of (a) is a sectional view taken along line XX shown in (b). Further, (b) is a plan view, but shows only the resistor and the upper surface electrode, and other members are omitted. Further, (c) shows only the lower surface electrode, and other members are omitted. 5 and 6 are also plan views, but only the resistor and the upper surface electrode are shown, and other members are omitted.

  In each figure, the Y1-Y2 direction indicates a direction perpendicular to the X1-X2 direction, and the Z1-Z2 direction indicates a direction perpendicular to the X1-X2 direction and the Y1-Y2 direction.

  A chip resistor A1 according to the present invention is a chip resistor for high power (specifically, several watts to several tens of watts), and is configured as shown in FIG. And a resistor 70 and a protective film 80.

  Here, the insulating substrate 10 is an insulator formed of alumina having a content rate of about 96%. The insulating substrate 10 has a substantially rectangular parallelepiped shape as a whole. In the example shown in FIG. 1, the insulating substrate 10 has a rectangular shape in plan view, but may have another shape, for example, a square shape. The insulating substrate 10 may be made of aluminum nitride.

  Further, as shown in FIG. 1, a total of a pair of electrode portions 20 are provided along the opposing side portions of the insulating substrate 10. Specifically, the electrode part 20 is provided along one short side (side in the Y1-Y2 direction) of the insulating substrate 10, and the electrode part 20 is provided along the other short side. Yes. In addition, although the electrode part 20 was formed along the short side, it may be formed along the long side.

  Here, the electrode part 20 has the upper surface electrode 30, the lower surface electrode 40, the side surface electrode 50, and the plating 60, as shown in FIG.

  A pair of upper surface electrodes 30 are formed at both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the upper surface of the insulating substrate 10. That is, one upper surface electrode 30 is formed to have a predetermined length from the end portion on the X1 side of the upper surface of the insulating substrate 10, and the other upper surface electrode 30 is an end portion on the X2 side of the upper surface of the insulating substrate 10. To a predetermined length. Specifically, the upper surface electrode 30 is formed of a silver-based thick film (silver-based metal glaze thick film). The width of the upper electrode 30 in the Y1-Y2 direction (width direction) is slightly larger than the width of the resistor 70 in the Y1-Y2 direction, and smaller than the width of the insulating substrate 10 in the Y1-Y2 direction. Is formed. Further, a gap is formed between the upper surface electrode 30 and the end portion of the insulating substrate 10 in the Y1-Y2 direction. The width of the upper surface electrode 30 in the Y1-Y2 direction may be the same as the width of the resistor 70 in the Y1-Y2 direction.

  Further, as shown in FIG. 1, a pair of lower surface electrodes 40 are formed in both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the lower surface of the insulating substrate 10. That is, one lower surface electrode 40 is formed to have a predetermined length from the end portion on the X1 side of the lower surface of the insulating substrate 10, and the other lower surface electrode 40 is an end portion on the X2 side of the lower surface of the insulating substrate 10. To a predetermined length. The length of the lower surface electrode 40 (length in the X1-X2 direction) is formed longer than that of the upper surface electrode 30, and the position of the end of the second resistor 74 in the lateral direction (X1-X2 direction) in a side view. It is formed up to. In other words, the position of the end portion on the X2 side of the lower electrode 40 on the X1 side and the position of the end portion on the X1 side of the second resistor 74 coincide in the lateral direction, and the lower surface electrode on the X2 side. The position of the end portion on the X1 side of 40 and the position of the end portion on the X2 side of the second resistor 74 coincide with each other in the lateral direction. In other words, the length of the lower surface electrode 40 (the length in the X1-X2 direction) is from the end portion (the end portion in the X1-X2 direction) of the second resistor 74 to the end portion (X1) of the upper surface of the insulating substrate. It can be said that it is the same as the length to the end in the −X2 direction.

  Note that the width of the bottom electrode 40 in the Y1-Y2 direction is substantially the same as the width of the insulating substrate 10 in the Y1-Y2 direction (may be the same). The lower surface electrode 40 is formed of a silver-based thick film (silver-based metal glaze thick film).

  The bottom electrode 40 is formed up to the position of the end of the second resistor 74 in the lateral direction (X1-X2 direction) in a side view, and the length of the bottom electrode 40 (the length in the X1-X2 direction). ) Is the same as the length from the end of the second resistor 74 (end in the X1-X2 direction) to the end of the upper surface of the insulating substrate (end in the X1-X2 direction). The position of the end portion of the electrode 40 and the position of the end portion of the second resistor 74 substantially coincide with each other in the horizontal direction, and the length of the lower surface electrode 40 (the length in the X1-X2 direction) is the second resistor 74. The length from the end portion (end portion in the X1-X2 direction) to the end portion (end portion in the X1-X2 direction) of the upper surface of the insulating substrate may be substantially the same.

  When the position of the end portion of the lower surface electrode 40 does not coincide with the position of the end portion of the second resistor 74 and slightly deviates, the position of the end portion of the lower surface electrode 40 is located on the other lower surface electrode 40 side. It is preferable to shift. That is, for the lower electrode 40 on the X1 side, the position of the end portion on the X2 side is preferably shifted to the X2 side instead of the X1 side, and for the lower electrode 40 on the X2 side, the position of the end portion on the X1 side is preferred. Is preferably shifted to the X1 side instead of the X2 side. By doing in this way, a cooling effect can be improved more. As described above, it can be said that any configuration in which the soldering surface (or electrode portion) is not formed in at least a part of the lower surface side region corresponding to the region of the low heat generation portion L (described later) may be used.

  The side electrode 50 includes a part of the upper surface electrode 30, a part of the lower surface electrode 40, a side surface of the insulating substrate 10 (that is, a side surface on the X1 side, a side surface on the X2 side, and a part of the side surface on the Y1 side. And a part of the side surface on the Y2 side) is formed in a layer shape with a substantially U-shaped cross section. The side electrodes 50 are provided at the end on the X1 side and the end on the X2 side, respectively.

  The plating 60 is composed of nickel plating (Ni plating) and tin plating, and is provided in the end region on the X1 side and the end region on the X2 side, respectively. That is, the plating 60 is provided on the surface of the electrode portion for connecting the chip resistor, the inner layer is nickel plating, and the outer layer is tin plating.

  Here, the nickel plating is formed so as to cover a part of the upper surface electrode 30, the side surface electrode 50, and a part of the lower surface electrode 40. That is, it is formed so as to cover the exposed portions of the upper electrode 30, the side electrode 50, and the lower electrode 40. This nickel plating is formed with a substantially uniform film thickness by electroplating. This nickel plating is made of nickel, and is formed to prevent internal corrosion of internal electrodes such as the upper surface electrode 30. In addition to nickel, this nickel plating may use copper plating.

  Further, the tin plating is disposed with a substantially uniform film thickness so as to cover the surface of the nickel plating. Note that solder plating may be used in addition to tin plating.

  In addition, the part formed in the lower part of the insulating substrate 10 in the electrode part 20 comprises the lower surface electrode part 22, and this lower surface electrode part 22 forms a soldering surface. That is, the soldering surface is formed by a part of the electrode portion 20. The lower surface electrode portion 22 includes the lower surface electrode 40, a part of the plating 60, and a part of the side surface electrode 50.

  As shown in FIG. 1, the resistor 70 is basically provided on the upper surface of the insulating substrate 10, and both end portions in the X1-X2 direction are laminated on the upper surface electrode 30. In other words, the resistor 70 is formed in a strip shape in the longitudinal direction (inter-electrode direction or energization direction) (X1-X2 direction (see FIG. 1)), and is formed in a substantially rectangular shape in plan view. Yes. The resistor 70 is formed so as to connect between the pair of upper surface electrodes 30.

  The resistor 70 includes a first resistor 72 and a second resistor 74. The second resistor 74 is formed in a layered manner on the upper surface of the insulating substrate 10, and has a rectangular shape in plan view. Presents. The position of the end portion (end portion in the X1-X2 direction) of the second resistor 74 coincides with the position of the end portion of the bottom electrode 40 in the lateral direction as described above. The second resistor 74 is formed of a ruthenium oxide thick film (for example, a ruthenium oxide metal glaze thick film). Note that the second resistor 74 may be formed of the same material as that of the upper surface electrode 30. That is, the resistance value of the silver-based thick film (silver-based metal glaze thick film) constituting the upper surface electrode is generally the resistance value of the ruthenium oxide-based thick film (for example, ruthenium oxide-based metal glaze thick film) constituting the resistor. Therefore, the second resistor 74 may be formed of a silver-based thick film (silver-based metal glaze thick film). In this case, it can be said that the second resistor 74 is formed of a low-resistance conductor made of an electrode material.

  The second resistor 74 is a low resistor, and has a resistance value lower than the resistance value of the region of the first resistor 72 laminated on the upper surface of the second resistor 74. For example, the material of the second resistor 74 is formed of a material having a smaller resistance value than the material of the first resistor 72. That is, when two resistors having the same shape and the same size are used, the resistance value of the second resistor 74 is made smaller than the resistance value of the first resistor 72. In order to make the material of the second resistor 74 lower in resistance value than the material of the first resistor 72, for example, the content ratio (weight ratio) of ruthenium oxide is increased compared to the first resistor 72, and the glass component It is conceivable to reduce the content ratio (weight ratio) of the first resistor 72 as compared with the first resistor 72.

  The first resistor 72 is provided on the upper surfaces of the insulating substrate 10 and the second resistor 74, and both end portions in the X1-X2 direction are stacked on the upper surface electrode 30. In other words, the first resistor 72 is formed in a band shape in the longitudinal direction (inter-electrode direction or energization direction) (X1-X2 direction (see FIG. 1)), and is formed in a substantially rectangular shape in plan view. Has been. The central region of the first resistor 72 is stacked in contact with the upper surface of the second resistor 74, and the thickness of the region is thinner than the thickness of the other regions of the first resistor 72. ing. The first resistor 72 is also formed of a ruthenium oxide thick film (for example, a ruthenium oxide metal glaze thick film).

  Note that, when current is passed between both ends of the resistor 70, almost the current flows through the second resistor 74 in the region where the second resistor 74 is formed. The heat generation in the region where the second resistor 74 is formed is smaller than the heat generation in other regions of the resistor 70. That is, as shown in FIG. 1, in the resistor 70, the region where the second resistor 74 is provided is the low heat generating portion L, and the region where the second resistor 74 is not provided is the high heat generating portion H1, H2. It becomes. The high heat generating portion H1, the low heat generating portion L, and the high heat generating portion H2 are provided in series connection. Note that the region of the resistor 70 that is in contact with the upper surface electrode 30 is in contact with the upper surface electrode 30 and therefore generates little heat and does not become a high heat generation portion.

  Therefore, a region on the lower surface side corresponding to the formation region of the high heat generating portions H1 and H2 in the insulating substrate 10 (“region immediately below the region of the high heat generating portions H1 and H2 in the lower surface region of the insulating substrate 10”) may be used. ), The lower surface electrode 40 is formed, and it can be said that the soldering surface is formed. Moreover, it can be said that the soldering surface is not formed in the lower surface side region corresponding to the region of the low heat generation portion L.

  When the end of the second resistor 74 and the end of the lower electrode 40 are aligned in the horizontal direction, the lower electrode 22 formed below the insulating substrate 10 in the electrode 20 is plated. Although it can be said that it protrudes inward by 60, the position of the end of the lower surface electrode part 22 including the plating 60 coincides with the position of the end of the second resistor 74 (may be substantially coincident). You may make it. In the above example, the second resistor 74 is laminated on the lower surface of the first resistor 72, but the second resistor 74 may be laminated on the upper surface of the first resistor 72.

  In the resistor 70, a region where the second resistor 74 is formed can be regarded as a low resistance portion, and a region other than the low resistance portion in the resistor 70 can be regarded as a high resistance portion.

  Further, as shown in FIG. 1, the protective film 80 is mainly disposed so as to cover the resistor 70. That is, the arrangement position of the protective film 80 will be described in more detail. In the Y1-Y2 direction, the protective film 80 is formed to be substantially the same (or the same as) the width of the insulating substrate 10 (shorter than the width of the insulating substrate 10). Further, the resistor 70 and a part of the upper surface electrode 30 are provided so as to cover the X1-X2 direction. The protective film 80 is made of resin (epoxy, phenol, silicon, etc.). In addition, you may form with a borosilicate glass.

  The manufacturing method of the chip resistor A1 having the above-described configuration will be briefly described. First, a solid alumina substrate having primary and secondary slits formed on both the front surface and the back surface (this alumina substrate has a plurality of chip resistors). And a bottom electrode is formed on the back surface (that is, the bottom surface) of the alumina substrate. That is, a paste for the lower surface electrode (for example, a silver-based paste such as silver-based metal glaze) is printed, dried and fired. In forming the lower surface electrode, the lower surface electrode is simultaneously formed for adjacent chip resistors. That is, the bottom electrode is formed in one printing region so as to straddle the primary slit in the region of the alumina substrate corresponding to the two chip resistors adjacent in the inter-electrode direction. Furthermore, in the direction perpendicular to the inter-electrode direction, a bottom electrode is formed continuously in a strip shape. That is, a plurality of chip resistors are collectively formed in the Y direction to form the bottom electrode in a series of strips, and two bottom electrodes adjacent to the X direction are formed together.

  Next, an upper surface electrode is formed on the front surface (that is, the upper surface) of the alumina substrate. That is, the top electrode paste is printed, dried and fired. The upper electrode paste in this case is a silver paste (for example, a silver metal glaze) or a silver palladium paste. In addition, when it becomes a chip resistor, the upper surface electrode which adjoins mutually by the upper surface electrode of an adjacent chip resistor is formed in one printing area | region.

  Next, the resistor 70 is formed on the front surface (that is, the upper surface) of the alumina substrate. That is, the second resistor 74 is formed, and then the first resistor 72 is formed. Specifically, the resistor paste of the second resistor 74 is printed and then dried and baked to form a resistor, and then the resistor paste of the first resistor 72 is printed and dried and baked to form a resistor. Form the body. For both the first resistor 72 and the second resistor 74, this resistor paste is a ruthenium oxide paste (for example, ruthenium oxide metal glaze). In the printing of the resistor paste when the first resistor 72 is formed, the first resistor 72 is formed so as to be laminated on the inner ends of the pair of upper surface electrodes.

  In the case where the second resistor 74 is formed of the same material as that of the upper surface electrode 30, the second resistor 74 may be formed simultaneously with the formation of the upper surface electrode. That is, when the upper surface electrode paste is printed, the upper surface electrode paste is also printed in the region of the second resistor 74, and is dried and fired.

  Next, a trimming groove is formed in the resistor 70 to adjust the resistance value. That is, a trimming groove is formed in the resistor 70 by laser trimming. The region for forming the trimming groove may be either the low heat generating portion L or the high heat generating portions H1 and H2.

  Next, a protective film is formed so as to cover at least the resistor 70. That is, the resin paste is printed in a strip shape, dried and cured. Note that a protective film is formed in the Y1-Y2 direction so as to be separated from the end of the insulating substrate.

  Thereafter, primary division is performed along the primary slit. Next, side electrodes are formed on the strip substrate. That is, the side electrode paste is printed, dried and cured. Alternatively, the side electrode paste may be printed, dried, and fired. Further, the side electrode may be formed of a metal thin film by sputtering. Thereafter, secondary division is performed along the secondary slit. Next, nickel plating is formed, and then tin plating is formed.

  The usage state of the chip resistor A1 will be described. The chip resistor A1 is used by being mounted on a wiring board (may be a printed board). FIG. 2 is an example in which the chip resistor A1 is mounted on the metal substrate base printed board 90. The metal substrate base printed board 90 includes an aluminum plate 92, an insulating layer 94 provided on the aluminum plate 92, and an insulating layer. 94, the chip resistor A1 is provided with a solder 98 between the electrode portion 20 and the conductor foil 96, thereby providing a metal substrate base printed circuit board. 90.

  When the chip resistor A1 is used, if a current flows between the pair of electrode portions 20, a current flows through the resistor 70. However, the second resistor 74 is provided in the low heat generating portion L of the resistor 70. In the low heat generating portion L, almost the current flows through the second resistor 74, and the heat generation from the low heat generating portion L is small. On the other hand, the heat generation amount from the high heat generation portions H1 and H2 is larger than that of the low heat generation portion L, but the lower surface electrode portion 22 is provided in the lower surface region of the insulating substrate 10 corresponding to the formation region of the high heat generation portions H1 and H2. Therefore, the heat generated from the high heat generating portions H 1 and H 2 is radiated from the lower surface electrode portion 22 through the insulating substrate 10. That is, in the chip resistor A1 of the present embodiment, the second resistor 74 is provided in the central region of the resistor 70 that is difficult to dissipate heat, thereby reducing the amount of heat generated and corresponding to the high heat generating portions H1 and H2. The lower surface electrode portion 22 is provided at the position where the heat is generated, and the heat generated from the high heat generation portions H1 and H2 is radiated from the lower surface electrode portion 22, so that the entire chip resistor A1 can be efficiently cooled. ing. In addition, although the heat from the high heat generating portions H1 and H2 is mainly radiated from the lower surface electrode portion 22, strictly speaking, it is also radiated from the electrode portions 20 other than the lower surface electrode portion 22.

  Further, even if a long distance between the pair of lower surface electrode portions 22 is ensured, heat generation can be suppressed by providing the second resistor 74 in a region corresponding to the region between the lower surface electrode portions 22, so that the chip resistor The insulation distance, that is, the distance between the pair of lower surface electrode portions 22 can be sufficiently secured while suppressing the heat generation, and the withstand voltage can be increased. That is, since the low heat generating portion L is provided, it is not necessary to provide the lower surface electrode portion 22 immediately below the low heat generating portion L (that is, the length of the lower surface electrode portion 22 itself is set as in the third example of FIG. It is not necessary to secure the insulation distance for a long time), and a sufficient insulation distance can be secured.

  As described above, according to the chip resistor A1 of the present embodiment, when the chip resistor A1 is mounted by soldering to a metal substrate, the entire chip resistor can be efficiently cooled. Since the insulation distance can be secured and the withstand voltage can be increased, a chip resistor that can be used with high power can be obtained. Further, in the chip resistor A1 of the present embodiment, the length of the lower surface electrode portion 22 is secured to some extent, so that when mounted on a metal substrate, the copper foil on the metal substrate has a good thermal conductivity. Therefore, the heat generation of the high heat generating portions H1 and H2 can be made uniform, and can be used with higher power than the conventional chip resistor.

  Note that the entire chip resistor can be efficiently cooled, and the effect of securing an insulation distance and increasing the withstand voltage can be obtained not only for metal substrates but also for alumina ceramic substrates and glass epoxy substrates. it can. The alumina ceramic substrate is a plate-shaped alumina ceramic with a copper foil formed on the top surface, and the glass epoxy substrate is a plate-shaped glass epoxy with a copper foil formed on the top surface, Also in these cases, since the copper foil has good thermal conductivity, the heat generation of the high heat generating portions H1 and H2 can be made uniform, and can be used with higher power than conventional chip resistors.

  Further, in the chip resistor A1 of the present embodiment, the lower surface electrode portion 22 is provided in a region corresponding to the high heat generation portions H1 and H2 on the lower surface of the insulating substrate 10 (that is, corresponding to the second resistor 74). Since the lower surface electrode portion 22 is provided in a region other than the region to be performed), the heat radiation efficiency to the wiring substrate is better when the substrate is thinned, and the insulating substrate can be thinned. In other words, in the conventional chip resistor, since the heat dissipation efficiency to the wiring board is not good, the insulating board is made thick to dissipate heat by heat conduction to the surrounding air and radiation to the surroundings. In the case of the embodiment, the heat radiation to the wiring board can be sufficiently performed, so even if the insulating board is thinned, the heat radiation effect due to the heat conduction to the surrounding air and the radiation to the surroundings becomes small enough. Therefore, it is possible to provide a chip resistor for high power using an inexpensive thin insulating substrate. In addition, since a thin insulating substrate is used, the chip resistor can be miniaturized.

  Further, a chip resistor that can be used with higher power can be obtained by using a high thermal conductive material such as aluminum nitride for the insulating substrate 10.

  As described above, according to the chip resistor of the present embodiment, a high-power chip resistor suitable for high power, miniaturization, and high integration of devices using metal substrates such as inverters and communication devices is obtained. be able to.

  Next, a modification of the first embodiment will be described. As shown in FIG. 3, the chip resistor A <b> 1 ′ in the modified example of the first embodiment has substantially the same configuration as the chip resistor A <b> 1, but the length of the bottom electrode 40 is different. That is, in the chip resistor A1 of the first embodiment, the end portion of the lower surface electrode 40 is formed in the lateral direction to the end portion position of the second resistor 74, but in the chip resistor A1 ′, the lower surface electrode is formed. 40 is not formed in the lateral direction to the position of the end of the second resistor 74, and is approximately half the length from the end of the upper surface of the insulating substrate 10 to the end of the second resistor 74. Is formed. That is, in each of the lower surface electrodes 40 in the pair of lower surface electrodes 40, the length of the lower surface electrode 40 (the length in the X1-X2 direction) α1 is from the end of the upper surface of the insulating substrate 10 to the end of the second resistor 74. For example, the length α1 is 40 to 60% of the length α2.

  Thus, even when the length of the lower surface electrode 40 is shorter than the length from the end of the upper surface of the insulating substrate 10 to the end of the second resistor 74, the heat generation from the high heat generating portions H1 and H2 Since heat is radiated from the portion 20 (particularly, the lower surface electrode portion 22), the heat radiation efficiency of the entire chip resistor A1 ′ can be sufficiently increased. That is, the heat generation from the high heat generation portions H1 and H2 is radiated from the electrode portion 20 (particularly, the lower surface electrode portion 22), and the heat generation from the low heat generation portion L is small. Can be high. That is, since the resistor 70 has the high heat generating portions H1 and H2 and the low heat generating portion L, and the high heat generating portions H1 and H2 are closer to the electrode portion 20 than the low heat generating portion L, the high heat generating portion H1 and Heat generated from H2 can be efficiently dissipated.

  In order to efficiently dissipate heat from the high heat generating portions H1 and H2, at least a part of the lower surface region of the insulating substrate 10 corresponding to the planar region of the high heat generating portions H1 and H2 is provided on the lower surface electrode 40. It is preferable that the lower electrode portion 22 may be formed. That is, it is preferable that a part of the lower surface electrode 40 (which may be the lower surface electrode part 22) overlaps at least a part of the regions of the high heat generation parts H1 and H2 in the vertical direction. For example, in the example of FIG. 3, it can be said that the region indicated by R in the bottom electrode 40 overlaps the high heat generation portion H1 in the vertical direction. The same applies to the lower electrode 40 on the X2 side. That is, as in the first embodiment, it is preferable that the lower surface electrode 40 is provided in the region corresponding to the high heat generating portions H1 and H2, and the end position of the lower surface electrode 40 is as much as possible as the second resistor 74. However, it is preferable that a part of the lower surface electrode 40 (or the lower surface electrode part 22) is vertically formed on at least a part of the regions of the high heat generation parts H1 and H2. It may be in a state of overlapping.

  Next, Example 2 will be described. The chip resistor A2 according to the second embodiment is configured as shown in FIGS. 4 to 6 and has substantially the same configuration as the chip resistor A1 according to the first embodiment, but the configuration of the resistor 70 is different.

  That is, the resistor 70 in the chip resistor A2 includes a first resistor 172 having a square shape, a second resistor 174 having a lattice shape, and a third resistor 176 having a shape arranged in a strip shape.

  That is, the first resistor 172 has a rectangular layer shape and is provided at a position between the second resistor 174 and the third resistor 176.

  The second resistor 174 is connected from the end of the first resistor 172 on the one upper surface electrode 30 side, and has a lattice shape. In addition, the width in the inter-electrode direction (X1-X2 direction) of the openings forming the lattice shape is formed so as to gradually increase toward the upper surface electrode 30 side.

  That is, the second resistor 174 includes a plurality of (six in the examples of FIGS. 4 to 6) strip-shaped portions 174a extending in the inter-electrode direction, and a coupling portion 174b and a coupling portion provided between the plurality of strip-shaped portions 174a. 174c and a connecting portion 174d.

  Here, the belt-like portion 174a is continuously provided from the end portion on the X1 side of the first resistor 172, and has a belt-like shape, that is, an elongated rectangular shape. The end of each strip 174a on the upper surface electrode 30 side is stacked on and in contact with the upper surface electrode 30.

  Further, the connecting portion 174b is provided in a direction perpendicular to the inter-electrode direction (Y1-Y2 direction) at a position through a gap having a length a from the end portion on the X1 side of the first resistor 172, and is adjacent to the band shape. It is provided so as to connect the portions 174a. A total of five connecting portions 174b are provided, but the five connecting portions 174b are provided in a line in the Y1-Y2 direction. Further, the connecting portion 174c is provided in a direction (Y1-Y2 direction) perpendicular to the inter-electrode direction at a position through a gap having a length c from the end portion on the X1 side of the connecting portion 174b, and is adjacent to the strip-like portion 174a. It is provided to connect the gaps. Although a total of five connecting portions 174c are provided, the five connecting portions 174c are provided in a line in the Y1-Y2 direction. In addition, the connecting portion 174d is provided in a direction (Y1-Y2 direction) perpendicular to the inter-electrode direction at a position through a gap having a length e from the end portion on the X1 side of the connecting portion 174c, and the adjacent belt-like portion 174a. It is provided to connect the gaps. Although a total of five connecting portions 174d are provided, the five connecting portions 174d are provided in a line in the Y1-Y2 direction. As described above, the second resistor 174 is formed in a lattice shape as a whole by providing the belt-like portion 174a and the connecting portions 174b to 174d.

  Here, the width b of the connecting portion 174b, the width d of the connecting portion 174c, and the width f of the connecting portion 174d are formed to be the same width, but the length a of the opening 175a and the length of the opening 175b. The length c and the length e of the opening 175c are formed such that a <c <e, and the length of the opening increases toward the upper surface electrode 30 side. As described above, since the length of the opening is increased as it goes to the upper surface electrode 30 side, the second resistor 74 has a resistance as it goes to the upper surface electrode 30 side in the X1-X2 direction. The value is increasing.

  In addition, the length h of the part on the tip side of the connecting part 174d in each band-like part 174a is formed longer than the width e of the opening 175c, and the part not in contact with the upper surface electrode 30 in the part on the tip side Is preferably larger than the width e of the opening 175c.

  As described above, the second resistor 174 is formed in the shape of the second resistor 174 by providing a rectangular opening in the rectangular shape and a rectangular notch at the end. I can say that.

  Next, the third resistor 176 is formed of a plurality (six in the example of FIGS. 4 to 6) of belt-like portions 176a, and each belt-like portion 176a has a belt shape, that is, an elongated rectangular shape. . Each belt-like portion 176a is connected from the end portion (the end portion on the X2 side) of the first resistor 172. The lengths and widths of the strips 176a are the same, and the gaps between the strips 176a are also the same. The end of each strip 176a on the upper surface electrode 30 side is laminated on and in contact with the upper surface electrode 30. It can be said that the third resistor 176 is provided by forming a part of the resistor in a slit shape.

  Further, the resistor 70 is integrally formed as a whole, is formed of the same material as a whole, and has the same thickness.

  Since the resistor 70 of the present embodiment is configured as described above, the second resistor 174 is configured to have a higher resistance value than the first resistor 172, and the third resistor 176 is The resistance value is higher than that of the one resistor 172. Thereby, as shown in FIG. 4, the resistor 70 is formed with high heat generating portions H <b> 1 and H <b> 2 and a low heat generating portion L. That is, the low heat generating portion L is configured by the first resistor 172, the high heat generating portion H1 is configured by a region not in contact with the upper surface electrode 30 of the second resistor 174, and the high heat generating portion H2 is configured by the third resistance. The body 176 is constituted by a region not in contact with the upper surface electrode 30. Here, the regions of the second resistor 174 and the third resistor 176 that are in contact with the upper surface electrode 30 are in contact with the upper surface electrode 30 and thus generate little heat and do not become a high heat generation portion.

  Therefore, a region on the lower surface side corresponding to the formation region of the high heat generating portions H1 and H2 in the insulating substrate 10 (“region immediately below the region of the high heat generating portions H1 and H2 in the lower surface region of the insulating substrate 10”) may be used. ), The lower surface electrode 40 is formed, and it can be said that the soldering surface is formed.

  In the resistor 70, the region of the first resistor 172 can be regarded as a low resistance portion, and the region of the second resistor 174 and the third resistor 176 can be regarded as a high resistance portion.

  Since the configuration of the chip resistor A2 other than those described above is the same as that of the chip resistor A1 of the first embodiment, detailed description thereof is omitted.

  The manufacturing method of the chip resistor A2 of this embodiment is the same as that of the chip resistor A1 of the first embodiment. However, in forming the resistor 70, the resistor paste is printed in the shape of the resistor 70 and then dried.・ Bake to form a resistor. That is, the resistor 70 is formed simultaneously on the whole.

  Further, when the resistance value of the resistor 70 is adjusted, the second resistor 174 or the third resistor 176 is trimmed. Specifically, the resistance value is adjusted by increasing the resistance value by forming a trimming groove in the second resistor 174 or the third resistor 176 in a direction perpendicular to the inter-electrode direction (Y1-Y2 direction).

  When a trimming groove is formed in the second resistor 174, a trimming groove is formed in the Y1-Y2 direction in at least one of the opening 175a, the opening 175b, and the opening 175c to adjust the resistance value. To do. A trimming groove may be formed in a region on the tip side (X1 side) from the connecting portion 174d (that is, a region having a length h (see FIG. 5)).

  In the second resistor 174, since the lengths of the openings 175a to 175c are formed to increase toward the upper surface electrode 30, the resistance value can be roughly adjusted and finely adjusted. In other words, even if the trimming groove having the same length is formed in the opening having the longer length, the resistance value increases greatly. Therefore, as shown in FIG. 6, the trimming groove T1 is formed at the position of the opening 175c. Then, after roughly adjusting the resistance value, the trimming groove T2 can be formed at the position of the opening 175b to finely adjust the resistance value. Note that, as shown in FIG. 6, the tip of the trimming groove is the position of the opening, not the middle position of the strip-shaped portion 174a. This is because if the tip of the trimming groove is located in the middle of the strip-shaped portion 174a, the second resistor 174 has a problem of cracking. In the chip resistor A2 according to the second embodiment, since the three openings having different lengths are provided in the second resistor 174, three resistance adjustment stages can be provided. It is possible to make the roughest adjustment at the position of 175c, perform the next rough adjustment at the position of the opening 175b, and perform the final fine adjustment at the position of the opening 175a. Note that if the region of the second resistor 174 on the tip side of the connecting portion 174d (that is, the region having the length h (see FIG. 5)) is also used as the trimming groove forming position, a <c <e <g. Thus, four stages of adjustment are possible.

  In the above description, the trimming grooves T1 and T2 are formed. However, as shown in FIG. 6, the trimming grooves are formed by being dispersed in the second resistor 174 like the trimming grooves T3 and T4. By doing so (in this case, the trimming grooves T1 and T2 are not formed), the heat generation becomes uniform and a higher-power chip resistor can be realized.

  In the third resistor 176, trimming is performed by forming a trimming groove in the Y1-Y2 direction and cutting the strip-shaped portion 176a. Also in this case, the trimming groove is located at the position of the gap between the band-like portions 176a without setting the tip of the trimming groove to a position in the middle of the band-like portion 176a.

  As described above, the tip of the trimming groove is not set as a position in the middle of the resistor as the position of the opening in the second resistor 174 or the position of the gap between the strips 176a in the third resistor 176. As a result, it is possible to ensure that no current flows through the cut portion, and thus a low-noise chip resistor can be provided.

  The chip resistor A2 in this embodiment is used in the same manner as the chip resistor A1 in the first embodiment, and is mounted on a wiring board such as a metal substrate base printed board or an alumina ceramic board. When the chip resistor A2 is used, if a current flows between the pair of electrode portions 20, a current flows through the resistor 70. The resistance value of the first resistor 172 is greater than that of the second resistor 174 and the third resistor 176. Therefore, the heat generation from the first resistor 172 (low heat generation portion L) is small, and the heat generation amount from the high heat generation portions H1 and H2 is larger than that of the low heat generation portion L, but the high heat generation portions H1 and H2 are high. Since the lower surface electrode portion 22 is provided on the lower surface of the insulating substrate 10 corresponding to the formation region, heat generated from the high heat generation portions H1 and H2 is radiated from the lower surface electrode portion 22 through the insulating substrate 10. That is, in the chip resistor A2 of the present embodiment, the heat generation amount is reduced by making the central region of the resistor 70, which is difficult to radiate heat, a low heat generation region, and the positions corresponding to the high heat generation portions H1 and H2. Is provided with a lower surface electrode portion 22, and heat generated from the high heat generation portions H1 and H2 is radiated from the lower surface electrode portion 22, so that the entire chip resistor A2 can be efficiently cooled. . In particular, since the resistance value of the second resistor 74 increases in the X1-X2 direction toward the upper surface electrode 30 side, the closer to the upper surface electrode 30 in the second resistor 174 as the high heat generating portion, the more Although it generates heat, it can be said that the heat dissipation efficiency is increased because it is closer to the electrode portion 20. In addition, although the heat from the high heat generating portions H1 and H2 is mainly radiated from the lower surface electrode portion 22, strictly speaking, it is also radiated from the electrode portions 20 other than the lower surface electrode portion 22.

  Further, even if a long distance between the pair of lower surface electrode portions 22 is secured, heat generation can be suppressed by providing the first resistor 172 as the low heat generating portion L in a region corresponding to the region between the lower surface electrode portions 22. Therefore, while suppressing the heat generation of the chip resistor, the insulation distance, that is, the distance between the pair of lower surface electrode portions 22 can be sufficiently secured, and the withstand voltage can be increased.

  Therefore, according to the chip resistor A2 of the present embodiment, when the chip resistor A2 is soldered and mounted on the metal substrate, the entire chip resistor can be efficiently cooled, and the insulation distance As a result, the withstand voltage can be increased and a chip resistor that can be used with high power can be obtained. Further, in the chip resistor A2 of the present embodiment, the length of the lower surface electrode portion 22 is ensured to a certain extent. Therefore, when mounted on the metal substrate, the copper foil on the metal substrate has a good thermal conductivity. Therefore, the heat generation of the high heat generating portions H1 and H2 can be made uniform, and can be used with higher power than the conventional chip resistor.

  Note that the entire chip resistor can be efficiently cooled, and the effect of securing an insulation distance and increasing the withstand voltage can be obtained not only for metal substrates but also for alumina ceramic substrates and glass epoxy substrates. it can.

  Further, in the chip resistor A2 of the present embodiment, the lower surface electrode portion 22 is provided in a region corresponding to the high heat generation portions H1 and H2 on the lower surface of the insulating substrate 10 as in the case of the chip resistor A1 ( In other words, the lower surface electrode portion 22 is provided in a region other than the region corresponding to the first resistor 172), so that the heat radiation efficiency to the wiring substrate is better when the substrate is thinner, and the insulating substrate is thinner. it can. Therefore, a chip resistor for high power can be provided using an inexpensive thin insulating substrate. In addition, since a thin insulating substrate is used, the chip resistor can be miniaturized.

  Further, a chip resistor that can be used with higher power can be obtained by using a high thermal conductive material such as aluminum nitride for the insulating substrate 10.

  As described above, according to the chip resistor of the present embodiment, a high-power chip resistor suitable for high power, miniaturization, and high integration of devices using metal substrates such as inverters and communication devices is obtained. be able to.

  In the second embodiment, the length of the lower surface electrode 40 may be shortened as in the modification of the first embodiment. That is, the lower surface electrode 40 is not formed in the lateral direction to the end portion position of the first resistor 172, and is approximately half the length from the end portion of the upper surface of the insulating substrate 10 to the end portion of the first resistor body 172. Form up to. That is, the length of the lower surface electrode 40 (the length in the X1-X2 direction) is approximately half from the end of the upper surface of the insulating substrate 10 to the end of the first resistor 172 (specifically, 40 to 60%). And

  Thus, even when the length of the lower surface electrode 40 is shorter than the length from the end of the upper surface of the insulating substrate 10 to the end of the first resistor 172, the heat generation from the high heat generating portions H1 and H2 Since heat is radiated from the electrode part 22, the heat dissipation efficiency of the entire chip resistor can be sufficiently increased.

  In order to efficiently dissipate heat from the high heat generating portions H1 and H2, at least a part of the lower surface region of the insulating substrate 10 corresponding to the planar region of the high heat generating portions H1 and H2 is provided on the lower surface electrode 40. It is preferable that the lower electrode portion 22 may be formed. That is, it is preferable that a part of the lower surface electrode 40 (which may be the lower surface electrode part 22) overlaps at least a part of the regions of the high heat generation parts H1 and H2 in the vertical direction. That is, as in the second embodiment, it is preferable that the lower surface electrode 40 is provided in the region corresponding to the high heat generating portions H1 and H2, and the position of the end portion of the lower surface electrode 40 is as much as possible. 172 is preferably formed up to the end position, but a part of the lower surface electrode 40 (which may be the lower surface electrode part 22) is located above and below at least a part of the regions of the high heat generation parts H1 and H2. You may make it the state which overlaps with a direction.

  In the second embodiment, the second resistor 174 has a lattice shape and the third resistor 176 has a strip shape. However, the present invention is not limited to this, and both may be a lattice shape, or both may be a strip shape. . In the second resistor 174, the size of the opening forming the lattice shape (particularly, the width in the X1-X2 direction) has been described as increasing toward the upper surface electrode 30 side. In terms of performing coarse adjustment and fine adjustment, the size of the opening may be reduced toward the top electrode 30 side. In addition, if it is not necessary to obtain the effect of rough adjustment and fine adjustment of the resistance value, the size of the opening (particularly, the width in the X1-X2 direction) may be the same and a normal lattice shape may be used.

  Next, Example 3 will be described. The chip resistor A3 according to the third embodiment is configured as shown in FIG. 7 and has substantially the same configuration as the chip resistor A1 and the chip resistor A2, but the configuration of the resistor 70 is different.

  That is, the resistor 70 in the chip resistor A <b> 3 includes a rectangular first resistor 272, a serpentine second resistor 274, and a serpentine third resistor 276.

  That is, the first resistor 272 has a rectangular layer shape and is provided at a position between the second resistor 274 and the third resistor 276.

  The second resistor 274 is connected from the end of the first resistor 272 on the X1 side, has a meandering shape, and the end is stacked on the upper surface electrode 30. That is, the second resistor 274 includes the vertical portion 274a, the horizontal portion 274b, the vertical portion 274c, the horizontal portion 274d, the vertical portion 274e, the horizontal portion 274f, and the vertical portion 274g. And has a meandering shape.

  The third resistor 276 is connected from the end of the first resistor 272 on the X2 side, has a meandering shape, and the end is stacked on the upper surface electrode 30. That is, the third resistor 276 includes a vertical portion 276a, a horizontal portion 276b, a vertical portion 276c, a horizontal portion 276d, a vertical portion 276e, a horizontal portion 276f, and a vertical portion 276g. And has a meandering shape.

  The second resistor 274 and the third resistor 276 are formed symmetrically with respect to each other so that they have the same shape even when the entire resistor 70 is rotated 180 degrees. The second resistor 274 and the third resistor 276 are formed by drying and firing after printing a resistor paste in the shape of each resistor. The resistor 70 is integrally formed as a whole.

  Since the resistor 70 of the present embodiment is configured as described above, the width of the current path of the second resistor 274 and the third resistor 276 is narrower than the width of the current path of the first resistor 272. The two-resistor 274 and the third resistor 276 are configured to have a higher resistance value than the first resistor 272. Thereby, as shown in FIG. 7, the resistor 70 is formed with high heat generating portions H <b> 1 and H <b> 2 and a low heat generating portion L. That is, the low heat generating portion L is configured by the first resistor 272, the high heat generating portion H1 is configured by a region not in contact with the upper surface electrode 30 of the second resistor 274, and the high heat generating portion H2 is configured by the third resistance. The body 276 is constituted by a region not in contact with the upper surface electrode 30. Here, since the region of the second resistor 274 and the third resistor 276 in contact with the upper surface electrode 30 is in contact with the upper surface electrode 30, heat generation is small and does not become a high heat generating portion.

  Therefore, a region on the lower surface side corresponding to the formation region of the high heat generating portions H1 and H2 in the insulating substrate 10 (“region immediately below the region of the high heat generating portions H1 and H2 in the lower surface region of the insulating substrate 10”) may be used. ), The lower surface electrode 40 is formed, and it can be said that the soldering surface is formed.

  In the resistor 70, the region of the first resistor 272 can be regarded as a low resistance portion, and the regions of the second resistor 274 and the third resistor 276 can be regarded as a high resistance portion.

  Since the configuration of the chip resistor A3 other than the above point is the same as that of the chip resistor A1 of the first embodiment, detailed description thereof is omitted.

  The manufacturing method of the chip resistor A3 of the present embodiment is the same as that of the chip resistor A1 of the first embodiment. However, in forming the resistor 70, the resistor paste is printed in the shape of the resistor 70 and then dried.・ Bake to form a resistor. That is, the resistor 70 is formed simultaneously on the whole. Further, when the resistance value of the resistor 70 is adjusted, trimming is performed on the resistor 70. The position where the trimming groove is formed is, for example, the first resistor 272. In addition, the resistance value may be adjusted by forming one of the two groove portions forming the meandering shape of the second resistor 274 and the third resistor 276 with a resistance pattern and the other with a trimming groove. In that case, trimming grooves may be formed in both the second resistor 274 and the third resistor 276, or may be formed in either one.

  Since the use state, operation, and effect of the chip resistor A3 of the present embodiment are the same as those of the chip resistor A1 and the chip resistor A2, detailed description thereof is omitted.

  As described above, according to the chip resistor of the present embodiment, a high-power chip resistor suitable for high power, miniaturization, and high integration of devices using metal substrates such as inverters and communication devices is obtained. be able to.

  In the third embodiment, the length of the bottom electrode may be shortened as in the modification of the first embodiment. Since the configuration and effects in this case are the same as those of the modification of the first embodiment, detailed description thereof is omitted.

  Next, Example 4 will be described. The chip resistor A4 according to the fourth embodiment is configured as shown in FIG. 8 and has the same configuration as each of the chip resistors, particularly the chip resistor A3, but the configuration of the resistor 70 is different. That is, the second resistor and the third resistor in the resistor 70 are formed in a meandering manner, but the way of forming the second resistor is different and is formed in a meandering manner by the trimming groove.

  That is, the resistor 70 in the chip resistor A4 includes a rectangular first resistor 372, a meandering second resistor 374, and a meandering third resistor 376.

  That is, the first resistor 372 has a rectangular layer shape and is provided at a position between the second resistor 374 and the third resistor 376.

  The second resistor 374 is connected to the end of the first resistor 372 on the X1 side, has a meandering shape, and the end is stacked on the upper surface electrode 30. The second resistor 374 includes a rectangular resistor body 374a, a connection portion 374b connecting the resistor body 374a and the upper surface electrode 30, and the resistor body 374a and the first resistor 372. The resistor body 374a is formed in a meandering manner by forming trimming grooves T11 and T12 in the resistor body 374a.

  The third resistor 376 is connected to the end of the first resistor 372 on the X2 side, has a meandering shape, and the end is stacked on the upper surface electrode 30. That is, the third resistor 376 includes the vertical portion 376a, the horizontal portion 376b, the vertical portion 376c, the horizontal portion 376d, the vertical portion 376e, the horizontal portion 376f, and the vertical portion 376g. And has a meandering shape. The third resistor 376 is formed by printing a resistor paste in the shape of the resistor, followed by drying and baking. The resistor 70 is integrally formed as a whole.

  Since the resistor 70 of the present embodiment is configured as described above, the width of the current path of the second resistor 374 and the third resistor 376 is narrower than the width of the current path of the first resistor 372. The two-resistor 374 and the third resistor 376 are configured to have a higher resistance value than the first resistor 372. Thereby, as shown in FIG. 8, the resistor 70 is formed with high heat generating portions H <b> 1 and H <b> 2 and a low heat generating portion L. That is, the low heat generating portion L is configured by the first resistor 372, the high heat generating portion H1 is configured by a region not in contact with the upper surface electrode 30 of the second resistor 374, and the high heat generating portion H2 is configured by the third resistance. The body 376 is constituted by a region not in contact with the upper surface electrode 30. Here, the regions of the second resistor 374 and the third resistor 376 that are in contact with the upper surface electrode 30 are in contact with the upper surface electrode 30 and therefore generate little heat and do not become a high heat generation portion.

  Therefore, a region on the lower surface side corresponding to the formation region of the high heat generating portions H1 and H2 in the insulating substrate 10 (“region immediately below the region of the high heat generating portions H1 and H2 in the lower surface region of the insulating substrate 10”) may be used. ), The lower surface electrode 40 is formed, and it can be said that the soldering surface is formed.

  In the resistor 70, the region of the first resistor 372 can be regarded as a low resistance portion, and the regions of the second resistor 374 and the third resistor 376 can be regarded as a high resistance portion.

  Since the configuration of the chip resistor A4 other than those described above is the same as that of the chip resistor A3 of the third embodiment, detailed description thereof is omitted.

  The manufacturing method of the chip resistor A4 of this embodiment is the same as that of the chip resistor A3 of the third embodiment. However, when forming the resistor 70, the trimming grooves T11 and T12 are formed in the shape of the resistor 70. After the resistor paste is printed in a non-printed shape, it is dried and fired, and then a trimming groove T11 and a trimming groove T12 are formed to form a resistor. In the example of FIG. 8, the resistance value is first roughly adjusted by the trimming groove T11, and then the resistance value is finely adjusted by the trimming groove T12. Note that the trimming groove T12 may be formed to perform coarse adjustment, and then the trimming groove T11 may be formed to perform fine adjustment.

  Since the use state, operation, and effect of the chip resistor A4 of this embodiment are the same as those of the chip resistors A1 to A3, detailed description thereof is omitted.

  In the fourth embodiment, the length of the bottom electrode may be shortened as in the modification of the first embodiment. Since the configuration and effects in this case are the same as those of the modification of the first embodiment, detailed description thereof is omitted.

  Next, Example 5 will be described. The chip resistor A5 of the fifth embodiment is configured as shown in FIG. 9 and has substantially the same configuration as the chip resistor A3, but the configuration of the resistor 70 is different. That is, the resistor 70 is integrally formed in the chip resistor A3, whereas in the resistor 70 of the present embodiment, the first resistor, the second resistor, and the third resistor are separated. Is formed. The material of the first resistor is formed of a material having a smaller resistance value than the materials of the second resistor and the third resistor.

  That is, the resistor 70 in the chip resistor A5 includes a rectangular first resistor 472, a meandering second resistor 474, and a meandering third resistor 476.

  That is, the first resistor 472 has a rectangular layer shape and is provided at a position between the second resistor 474 and the third resistor 476. The material of the first resistor 472 is formed of a material having a smaller resistance value than the materials of the second resistor 474 and the third resistor 476. Thus, in order to set the material of the first resistor 472 to a resistance value lower than that of the material of the second resistor 474 or the third resistor 476, for example, the content ratio (weight ratio) of ruthenium oxide is set to the second resistor. More than 474 and the third resistor 476. Note that the first resistor 472 may be formed of the same material as that of the upper surface electrode 30. That is, the first resistor 472 may be formed of a low resistance conductor made of an electrode material.

  The second resistor 474 is connected to the end portion on the X1 side of the first resistor 472 and has a meandering shape, and the end portion on the upper surface electrode 30 side is laminated on the upper surface electrode 30 to form the first resistor. The end on the body 472 side is stacked on the first resistor 472. Since the configuration of the second resistor 474 is the same as that of the second resistor 274 in the chip resistor A3, detailed description thereof is omitted.

  The third resistor 476 is connected to the end of the first resistor 472 on the X2 side, has a meandering shape, and the end of the upper surface electrode 30 is stacked on the upper surface electrode 30 to form the first resistor. The end on the body 472 side is stacked on the first resistor 472. Since the configuration of the third resistor 476 is the same as that of the third resistor 276 in the chip resistor A3, detailed description thereof is omitted.

  Note that the second resistor 474 and the third resistor 476 are formed symmetrically with respect to each other so that the same shape is obtained even when the entire resistor 70 is rotated 180 degrees. The second resistor 474 and the third resistor 476 are formed by drying and firing after printing a resistor paste in the shape of each resistor.

  The resistor 70 of the present embodiment is configured as described above, and the width of the current path of the second resistor 474 and the third resistor 476 is formed narrower than the width of the current path of the first resistor 472, Further, since the material of the first resistor 472 is formed of a material having a lower resistance value than the material of the second resistor 474 or the third resistor 476, the second resistor 474 and the third resistor 476 are The resistance value is higher than that of the first resistor 472. Thereby, as shown in FIG. 9, the resistor 70 is formed with the high heat generation portions H1 and H2 and the low heat generation portion L. That is, the low heat generating portion L is configured by the first resistor 472, and the high heat generating portion H1 is configured by a region that is not in contact with the upper surface electrode 30 of the second resistor 474 or the first resistor 472. H <b> 2 is configured by a region not in contact with the upper surface electrode 30 or the first resistor 472 of the third resistor 476. Here, the region in contact with the upper surface electrode 30 and the first resistor 472 of the second resistor 474 and the third resistor 476 is small in heat generation and does not become a high heat generating portion.

  Therefore, a region on the lower surface side corresponding to the formation region of the high heat generating portions H1 and H2 in the insulating substrate 10 (“region immediately below the region of the high heat generating portions H1 and H2 in the lower surface region of the insulating substrate 10”) may be used. ), The lower surface electrode 40 is formed, and it can be said that the soldering surface is formed.

  In the resistor 70, the region of the first resistor 472 can be regarded as a low resistance portion, and the region of the second resistor 474 or the third resistor 476 can be regarded as a high resistance portion.

  Since the configuration of the chip resistor A5 other than the above points is the same as that of the chip resistor A3, detailed description thereof is omitted.

  The manufacturing method of the chip resistor A5 of the present embodiment is the same as that of the chip resistor A1 of the first embodiment. However, in forming the resistor 70, the first resistor 472 is formed and then the second resistor. 474 and a third resistor 476 are formed. That is, after the resistor paste is printed in the shape of the first resistor 472, it is dried and baked to form a resistor to form the first resistor 472, and then the second resistor 474 and the third resistor 476 are formed. After the resistor paste is printed in the above shape, the resistor is formed by drying and baking to form the second resistor 474 and the third resistor 476. That is, the second resistor 474 and the third resistor 476 are formed simultaneously. In the case where the first resistor 472 is formed of the same material as that of the upper surface electrode 30, the first resistor 472 may be formed simultaneously with the formation of the upper surface electrode 30. Further, when the resistance value of the resistor 70 is adjusted, trimming is performed on the resistor 70, and the first resistor 472 is preferably used as a position where the trimming groove is formed.

  Since the use state, operation, and effect of the chip resistor A5 of this embodiment are the same as those of the chip resistors A1 to A4, detailed description thereof is omitted.

  In the fifth embodiment, the length of the bottom electrode may be shortened as in the modification of the first embodiment. Since the configuration and effects in this case are the same as those of the modification of the first embodiment, detailed description thereof is omitted.

  Next, Example 6 will be described. The chip resistor A6 according to the sixth embodiment is configured as shown in FIG. 10, and unlike the chip resistors, the upper surface electrode 30 is secured relatively long and the resistor 70 on the lower surface of the insulating substrate 10 is high. A feature is that a heat conductive film 42 is provided in a region corresponding to the heat generating portion.

  That is, the chip resistor A6 is a high-power chip resistor, which is configured as shown in FIG. 10, and includes the insulating substrate 10, the electrode unit 20, the resistor 70, the protective film 80, and the heat conducting unit. 24.

  Here, the configuration of the insulating substrate 10 is the same as the configuration of the insulating substrate 10 in each of the chip resistors A1 to A5.

  The configuration of the electrode unit 20 is substantially the same as the configuration of the electrode unit 20 of each chip resistor, but the upper surface electrode 30 is longer than the lower surface electrode 40 in the inter-electrode direction (X1-X2 direction). The point is different. The upper surface electrode 30 is formed in the lateral direction up to the position of the end portion of the heat conductive film 42 to secure a distance between the lower surface electrode portion 22 and the heat conductive portion 24, that is, an insulation distance, and In order to secure the length to some extent, the length of the upper surface electrode 30 (length in the interelectrode direction) is preferably at least twice the length of the lower surface electrode 40 (length in the interelectrode direction). The length 30 (length in the interelectrode direction) is preferably 25 to 35% of the length of the insulating substrate 10 (length in the interelectrode direction). Since the configuration of the electrode unit 20 other than the above points is the same as that of the electrode unit 20 in the chip resistor A1, detailed description thereof is omitted.

  The resistor 70 is basically provided on the upper surface of the insulating substrate 10, and both end portions in the X1-X2 direction are laminated on the upper surface electrode 30. That is, the resistor 70 is formed in a strip shape in the longitudinal direction (inter-electrode direction) (X1-X2 direction (see FIG. 10)), and is formed in a substantially rectangular shape in plan view. The resistor 70 is formed so as to connect between the pair of upper surface electrodes 30. The resistor 70 is formed of a ruthenium oxide thick film (for example, a ruthenium oxide metal glaze thick film), and is integrally formed as a whole. The resistor 70 is not provided with a high heat generating portion and a low heat generating portion as in the above embodiments.

  The configuration of the protective film 80 is the same as that of the protective film 80 in the chip resistor A1, but is configured to cover at least the entire resistor 70 and a part of the upper surface electrode 30. At this time, the upper surface electrode 30 is completely covered with the protective film 80 in the Y1-Y2 direction. That is, in the case of the chip resistor A6 of the present embodiment, the length of the upper surface electrode 30 in the X1-X2 direction is relatively long, so that the width of the protective film 80 ( The width in the Y1-Y2 direction) is made larger than the width of the upper surface electrode 30 so that the upper surface electrode 30 is completely covered in the Y1-Y2 direction and as long as possible in the X1-X2 direction. That is, for example, if the upper surface electrode 30 is exposed and moisture or the like adheres to the upper surface electrode 30, current flows excessively and the withstand voltage decreases, so that the upper surface electrode 30 is surely covered by the protective film 80 and the plating 60. . This also applies to the upper surface electrode 30 and the upper surface electrode 32 of Example 7 described later, and the upper surface electrodes 30-1 and 30-2 of Example 8.

  In addition, the heat conducting part 24 is composed of a heat conducting film 42 and a plating 60, and the heat conducting film 42 is formed of the same material as the lower surface electrode 40 and is formed in a square shape.

  The width (width in the Y1-Y2 direction) of the heat conductive film 42 (which may be the heat conduction portion 24) is formed in the same manner as the width of the insulating substrate, and the length (length in the X1-X2 direction) is a pair of upper surfaces. One end portion (X1 side end portion) of the heat conductive film 42 is formed in the same distance as the distance between the electrodes 30, and is an end on the inner side of one upper surface electrode 30 (X1 side upper surface electrode 30). And the other end portion (X2 side end portion) of the heat conductive film 42 in the lateral direction is the other upper surface electrode 30 (X2 side upper surface electrode 30). ) On the inner end (X1 end). That is, the heat conductive film 42 is formed in a region corresponding to a region not stacked on the upper surface electrode 30 of the resistor 70. Further, the plating 60 in the heat conducting portion 24 is formed so as to cover the surface of the heat conducting film 42.

  Since the chip resistor A6 is configured as described above, the region of the resistor 70 that is not in contact with the upper surface electrode 30 becomes the high heat generation portion H, and the region of the upper surface electrode 30 becomes the low heat generation portions L1 and L2. Since the upper surface electrode 30 functions as a low heat generating portion, the region covered with the protective film 80 on the upper surface electrode 30 functions as at least a low heat generating portion. As described above, it can be said that the heat conductive film 42 is provided in the region corresponding to the high heat generation portion H on the lower surface of the insulating substrate 10. Therefore, it can be said that a soldering surface is formed in a region on the lower surface side of the insulating substrate 10 corresponding to a region not in contact with the upper surface electrode 30 in the resistor 70.

  In the above description, the heat conductive film 42 is formed in a region corresponding to a region not stacked on the upper surface electrode 30 of the resistor 70, but is not stacked on the upper surface electrode 30 of the resistor 70. The heat conducting portion 24 may be formed in a region corresponding to the region. That is, one end portion (X1 side end portion) of the heat conducting portion 24 is in the lateral direction, and the inner end portion (X2 side end portion) of one upper surface electrode 30 (X1 side upper surface electrode 30). In addition, the other end portion (X2 side end portion) of the heat conducting portion 24 is in the lateral direction, and the inner end portion (X1 side) of the other upper surface electrode 30 (X2 side upper surface electrode 30). It is good also as what corresponds with the edge part.

  In addition, since the heat generation from the low heat generation portions L1 and L2 is small, the lower surface side region corresponding to the region of the low heat generation portions L1 and L2 in the insulating substrate 10 does not particularly require a soldering surface. The insulating substrate 10 may have a configuration in which a soldering surface is not formed in at least a part of the lower surface side region corresponding to the regions of the low heat generation portions L1 and L2, and also dissipates heat from the high heat generation portion. In order to achieve this, it can be said that it is necessary to have a configuration in which a soldering surface is formed in at least a part of the lower surface side region corresponding to the region of the high heat generating portion H.

  The manufacturing method of the chip resistor A6 is substantially the same as that of the chip resistor A1, but when the lower surface electrode 40 is formed, the heat conductive film 42 is also formed at the same time. When the upper surface electrode 30 is formed, the lower surface electrode is formed as described above. In addition to forming the resistor 70 longer than the electrode 40, the resistor 70 is formed by printing and drying and baking the resistor paste in the same manner as a normal resistor. In plating, the heat conductive film 42 is also plated.

  Since the usage state, operation, and effect of the chip resistor A6 of the present embodiment are the same as those of the chip resistors A1 to A5, detailed description thereof is omitted, but in the present embodiment, not only the lower surface electrode portion 22 is used. When the chip resistor A6 is used, when the current flows between the pair of electrode portions 20, when the current flows between the pair of electrode portions 20, a current flows through the resistor 70. The generated heat is dissipated from the heat conducting portion 24, and the heat generation from the low heat generating portions L1 and L2 is small, so that the chip resistor can be efficiently cooled. In addition, since the upper surface electrode 30 is formed longer than the lower surface electrode 40, the distances α11 and α12 between the lower surface electrode portion 22 and the heat conducting portion 24 are ensured by securing the length of the upper surface electrode 30 to some extent. Since the length can be secured, a sufficient insulation distance can be secured and the withstand voltage can be increased.

  Next, Example 7 will be described. The chip resistor A7 according to the seventh embodiment is configured as shown in FIG. 11 and has substantially the same configuration as the chip resistor A6 according to the sixth embodiment, but the upper surface electrode 30 is formed longer in the chip resistor A6. In contrast, the chip resistor A7 is different in that the length of the upper surface electrode is secured long by providing the second upper surface electrode 32 inside the upper surface electrode 30.

  In other words, the length of the upper surface electrode 30 (the length in the X1-X2 direction) is the same as the length of the lower surface electrode 40, but the second upper surface electrode 32 is further connected to the inside of the upper surface electrode 30. Yes. In the connection portion between the upper surface electrode 30 and the second upper surface electrode 32, the second upper surface electrode 32 is laminated on the upper surface electrode 30. Thus, the total length (length in the inter-electrode direction) α21 of the upper surface electrode composed of the upper surface electrode 30 and the second upper surface electrode 32 by the upper surface electrode 30 and the second upper surface electrode 32 is the length of the lower surface electrode 40. The length α21 is preferably 25% to 35% of the length of the insulating substrate 10 (the length in the inter-electrode direction). . Since the configuration of the electrode unit 20 other than the above points is the same as that of the chip resistor A6, detailed description thereof is omitted.

  The configuration of the protective film 80 is the same as that of the protective film 80 in the chip resistor A7, and is configured to cover at least the entire resistor 70 and most of the upper surface electrode 32. At that time, the upper surface electrode 32 is completely covered with the protective film 80 in the Y1-Y2 direction. That is, in the case of the chip resistor A7 of this embodiment, the length of the upper surface electrode composed of the upper surface electrode 30 and the upper surface electrode 32 in the X1-X2 direction is relatively long, so that the upper surface electrode is prevented from being exposed. In addition, the upper surface electrode is completely covered in the Y1-Y2 direction and is also covered as long as possible in the X1-X2 direction.

  Since the chip resistor A7 is configured as described above, the region of the resistor 70 that is not in contact with the second upper surface electrode 32 becomes the high heat generation portion H, and the region of the upper surface electrode 30 and the second upper surface electrode 32 is low. It becomes the heat generating parts L1 and L2. That is, it can be said that the heat conductive film 42 is provided in a region corresponding to the high heat generating portion H on the lower surface of the insulating substrate 10. Therefore, it can be said that a soldering surface is formed in a region on the lower surface side of the insulating substrate 10 corresponding to a region not in contact with the second upper surface electrode 32 in the resistor 70.

  In the above description, the heat conductive film 42 is formed in the region corresponding to the region not stacked on the second upper surface electrode 32 of the resistor 70, but the second upper surface electrode 32 of the resistor 70 is formed. The heat conducting portion 24 may be formed in a region corresponding to a region that is not stacked. That is, one end portion (X1 side end portion) of the heat conducting portion 24 is in the lateral direction, and the inner end portion (X2 side end portion) of one second upper surface electrode 32 (X1 side second upper surface electrode 32). And the other end portion (X2 side end portion) of the heat conducting portion 24 in the lateral direction is the other second upper surface electrode 32 (X2 side second upper surface electrode 32). It is good also as what corresponds with the edge part inside (X1 side edge part).

  The manufacturing method of the chip resistor A7 is substantially the same as that of the chip resistor A6, but the second upper surface electrode 32 is formed after the upper surface electrode 30 is formed. In forming the lower surface electrode 40, the heat conductive film 42 is also formed at the same time.

  Since the usage state and the obtained effect of the chip resistor A7 are the same as those of the chip resistor A6, detailed description thereof is omitted.

  Next, Example 8 will be described. The chip resistor A8 of Example 8 is configured as shown in FIG. 12, and has a configuration in which one of the pair of lower surface electrodes is formed long and disposed below the high heat generating portion of the resistor. .

  That is, the chip resistor A8 includes the insulating substrate 10, the electrode unit 20, the resistor 70, and the protective film 80.

  Here, the configuration of the insulating substrate 10 is the same as the configuration of the insulating substrate 10 in each of the chip resistors A1 to A7.

  The configuration of the electrode unit 20 is substantially the same as the configuration of the electrode unit 20 of each chip resistor. However, in the pair of upper surface electrodes, the upper electrode 30-1 on the X1 side is the upper electrode 30-2 on the X2 side. And shorter in the inter-electrode direction (X1-X2 direction).

  In the pair of lower surface electrodes, the lower surface electrode 40-1 on the X1 side is formed longer in the inter-electrode direction (X1-X2 direction) than the lower surface electrode 40-2 on the X2 side. Furthermore, the long bottom electrode 40-1 of the pair of bottom electrodes is formed longer than the top electrode 30-1 in the inter-electrode direction, and is a region not stacked on the top electrode of the resistor 70. It is provided to be located on the lower side. That is, the end portion on the X2 side of the lower surface electrode 40-1 coincides with the end portion on the X2 side of the region not in contact with the upper surface electrodes 30-1 and 30-2 of the resistor 70. As a result, the region of the resistor 70 that is not in contact with the upper surface electrodes 30-1 and 30-2 becomes the high heat generation portion H, but the region corresponding to the high heat generation portion H on the lower surface of the insulating substrate 10 (that is, The lower surface electrode 40-1 is provided in the lower region of H). The lower surface electrode 40-2 is formed shorter than the upper surface electrode 30-2 in the inter-electrode direction.

  The configuration of the protective film 80 is the same as that of the protective film 80 in the chip resistors A7 and A8, and is configured to cover at least the entire resistor 70 and a part of the upper surface electrodes 30-1 and 30-2. . At this time, the upper surface electrodes 30-1 and 30-2 are completely covered with the protective film 80 in the Y1-Y2 direction. That is, in the case of the chip resistor A8 of this embodiment, in particular, since the length of the upper surface electrode 30-2 in the X1-X2 direction is relatively long, the upper surface electrode 30 is prevented in order to prevent the upper surface electrode from being exposed. -2 is completely covered in the Y1-Y2 direction, and is also covered as long as possible in the X1-X2 direction.

  Since the chip resistor A8 is configured as described above, the region of the resistor 70 that is not in contact with the upper surface electrodes 30-1 and 30-2 becomes the high heat generation portion H, and the upper surface electrodes 30-1 and 30-2. These regions are the low heat generation portions L1 and L2. That is, it can be said that the lower surface electrode 40-1 is provided in a region corresponding to the high heat generation portion H on the lower surface of the insulating substrate 10 (that is, a region below the high heat generation portion H). Therefore, a soldering surface (that is, the lower surface electrode 40-1) is provided in a region on the lower surface side of the insulating substrate 10 corresponding to a region not in contact with the upper surface electrodes 30-1 and 30-2 in the resistor 70. It can be said that it is formed.

  In the above description, the lower surface electrode 40-1 is formed in the region corresponding to the region not stacked on the upper surface electrodes 30-1 and 30-2 of the resistor 70. The lower surface electrode portion 22-1 may be formed in a region corresponding to a region not stacked on the electrodes 30-1 and 30-2. That is, the end portion (the end portion on the X2 side) of the lower surface electrode portion 22-1 may be aligned with the end portion on the X2 side of the high heat generating portion H in the lateral direction.

  The manufacturing method of the chip resistor A8 is substantially the same as the chip resistor A1, but in forming the lower surface electrode, the lower surface electrode 40-1 is formed longer than the lower surface electrode 40-2, and in forming the upper surface electrode. The upper surface electrode 30-2 is formed longer than the upper surface electrode 30-1. In forming the resistor 70, the resistor paste is printed and then dried and fired in the same manner as a normal resistor.

  Since the usage state, operation, and effect of the chip resistor A8 of this embodiment are the same as those of the chip resistors A1 to A7, detailed description is omitted, but when using the chip resistor A8, the pair of electrode portions 20 is used. When a current flows between them, a current flows through the resistor 70, but the heat generated from the high heat generating portion H in the resistor 70 is dissipated from the lower surface electrode portion 22-1 located on the lower side, and the low heat generating portion. Since the heat generated from L1 and L2 is small, the chip resistor can be efficiently cooled. Further, since the upper surface electrode 30-2 is formed longer than the lower surface electrode 40-2, by ensuring the length of the upper surface electrode 30-2 to some extent, the lower surface electrode portion 22-1 and the lower surface electrode portion 22- 2 can be secured, the insulation distance can be sufficiently secured, and the withstand voltage can be increased.

  In each of the embodiments, the resistor 70 is connected to the upper surface electrodes 30, 30-1, 30-2 (or the second upper surface electrode 32). 1 and 30-2 (or the second upper surface electrode 32) are described as being stacked on the upper surface, but in the connection region with the upper surface electrodes 30, 30-1, 30-2 (or the second upper surface electrode 32). The upper surface electrodes 30, 30-1 and 30-2 (or the second upper surface electrode 32) may be laminated on the upper surface of the resistor 70.

  The chip resistor of the present invention is particularly applicable to a high power chip resistor.

It is a figure which shows the chip resistor of Example 1, and is a figure which shows sectional drawing, a top view, and a bottom view. It is sectional drawing which shows the use condition of the chip resistor of Example 1. FIG. It is a figure which shows the chip resistor as a modification of Example 1, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 2, and is a figure which shows sectional drawing, a top view, and a bottom view. 6 is a plan view of a chip resistor of Example 2. FIG. FIG. 10 is an explanatory diagram illustrating an example of trimming in the chip resistor of the second embodiment. It is a figure which shows the chip resistor of Example 3, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 4, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 5, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 6, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 7, and is a figure which shows sectional drawing, a top view, and a bottom view. It is a figure which shows the chip resistor of Example 8, and is a figure which shows sectional drawing, a top view, and a bottom view. It is explanatory drawing which shows the structure of the conventional high voltage chip resistor.

Explanation of symbols

A1, A1 ′, A2, A3, A4, A5, A6, A7, A8 Chip resistor 10 Insulating substrate 20 Electrode part 22, 22-1, 22-2 Lower surface electrode part 24 Heat conduction part 30, 30-1, 30 -2 upper surface electrode 32 second upper surface electrode 40, 40-1, 40-2 lower surface electrode 42 thermal conductive film 50 side electrode 60 plating 70 resistor 72, 172, 272, 372, 472 first resistor 74, 174, 274 374, 474 Second resistor 80 Protective film 90 Metal substrate Base printed circuit board 176, 276, 376, 476 Third resistor H1, H2, H High heat generating part L, L1, L2 Low heat generating part

Claims (9)

A chip resistor,
An insulating substrate;
A pair of electrode portions provided on the insulating substrate;
A resistor provided to connect the pair of electrode portions, wherein a high heat generating portion and a low heat generating portion are connected in series, and the high heat generating portion is closer to the electrode portion than the low heat generating portion. A resistor provided in
Have
2. The chip resistor according to claim 1, wherein the electrode portion is formed up to at least a part of a region on the lower surface side corresponding to the region of the high heat generating portion in the insulating substrate. A chip resistor,
An insulating substrate;
A pair of electrode portions provided on the insulating substrate;
A resistor provided to connect the pair of electrode portions, a resistor provided by connecting a high heat generating portion and a low heat generating portion in series;
Have
A chip resistor, wherein a soldering surface is formed in at least a part of a region on a lower surface side corresponding to the region of the high heat generating portion in the insulating substrate. The chip resistor according to claim 2, wherein the high heat generating portion is provided closer to the upper surface electrode than the low heat generating portion. The chip resistor according to claim 2, wherein the soldering surface is formed as a part of an electrode portion. The chip resistor according to claim 1, 2, 3, or 4, wherein the high heat generating portion in the resistor is formed by forming a part of the resistor in a lattice shape. The chip resistor according to claim 1, 2, 3, 4, or 5, wherein the high heat generating portion in the resistor is formed by forming the resistor in a slit shape. The chip resistor according to claim 1, 2, 3, 4, 5, or 6, wherein the high heat generating portion in the resistor is formed by narrowing the width of the resistance path as compared with the low heat generating portion. vessel. The chip resistor according to claim 7, wherein the high heat generating portion is formed in a meandering shape. A chip resistor,
An insulating substrate;
A pair of lower surface electrodes formed on the lower surface of the insulating substrate;
A pair of upper surface electrodes formed on the upper surface of the insulating substrate and formed longer than the lower surface electrode;
A resistor formed between the top electrodes;
A protective film covering a part of the upper surface electrode;
Have
The width of the protective film is formed larger than the width of the upper surface electrode,
The upper surface electrode is a low heat generating portion, and the region between the upper surface electrodes in the resistor is a high heat generating portion,
A chip resistor, wherein a soldering surface is formed in at least a part of a region on the lower surface side corresponding to the region of the high heat generating portion in the insulating substrate.

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