JP5096672B2 - Chip resistor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a chip resistor excellent in surge resistance and a manufacturing method thereof.

  In general, in a chip resistor, a resistive film is formed on the upper surface of an insulating substrate configured in a rectangular shape in plan view so as to extend in the longitudinal direction of the rectangle. A terminal electrode for soldering is formed on each of the short side surfaces so that the terminal electrode is electrically connected to both ends of the resistance film via an upper surface electrode formed on the upper surface of the insulating substrate. As is well known, the two terminal electrodes are configured to be soldered to a printed circuit board or the like.

  In this well-known chip resistor, the thermal expansion / contraction in the insulating substrate due to the heat generation of the resistive film is large in the longitudinal direction of the rectangle, but the terminals on the short side surfaces at both ends in the longitudinal direction of the rectangle. By providing electrodes and soldering mounting with both terminal electrodes, the thermal stress due to the large thermal expansion / contraction repeatedly acts on the soldered portions with both terminal electrodes. In addition, since the soldering area is small, there has been a problem that there is a high possibility that the soldering will be removed at this soldering portion.

Therefore, in Patent Document 1 as the prior art, as described above, the resistive film is formed on the upper surface of the insulating substrate configured to be rectangular in plan view so as to extend in a direction perpendicular to the longitudinal direction of the rectangle. On the other hand, terminal electrodes for soldering to both ends of the resistance film are formed so as to extend over substantially the entire length of the long side surface on the long side surfaces at both ends of the insulating substrate in the direction perpendicular to the longitudinal direction of the rectangle. A chip resistor is proposed.

According to this prior art configuration, the thermal expansion / contraction of the insulating substrate in the direction perpendicular to the longitudinal direction of the rectangle is smaller than the thermal expansion / contraction in the longitudinal direction of the rectangle. Since the soldering area is greatly increased by forming the terminal electrode on the side surface of the long side, it is possible to reliably reduce the possibility that the soldering will be detached from the soldered portion.
JP-A-11-111505

  However, in the above prior art, the direction in which the wide resistive film extends is perpendicular to the longitudinal direction of the rectangle, so that the length of the path through which current flows in the resistive film is rectangular. This is shorter than the case of extending in the longitudinal direction of the film, so that the surge resistance of the resistive film is low. In other words, the surge resistance cannot be improved.

  Further, in the prior art, when the trimming groove extending in the width direction is formed in the resistance film so that the resistance value in the resistance film is adjusted to a predetermined value, the trimming groove The length of the film in the wide direction must be engraved or the number of trimming grooves must be increased, and this requires a long time. This increases the cost required for engraving the trimming grooves. It was also a problem to invite.

  An object of the present invention is to provide a chip resistor that solves these problems and a method of manufacturing the same.

In order to achieve this technical problem, a chip resistor according to the present invention is as described in claim 1.
"An insulating substrate which is rectangular in plan view, a resistive film formed on the upper surface of the insulating substrate, a pair of upper surface electrode connecting portion of the formed on the upper surface of the insulating substrate Rutotomoni the resistive film overlap, the insulating substrate In the chip resistor comprising a pair of terminal electrodes formed so as to be electrically connected to the upper surface electrodes on both the left and right long side surfaces extending in the longitudinal direction of the rectangle,
Each of the upper surface electrodes is formed on a portion of the upper surface of the insulating substrate adjacent to the long side surface of the insulating substrate , and the upper surface electrode is in a direction along the long side of the resistance film of the upper surface electrode. While the width of the resistor film is longer than the width in the direction along the long side of the insulating substrate in the connection portion of the resistance film, the strip extends long along the side of the long side of the insulating substrate ,
Wherein the one end of the resistor film, wherein the connection to one of the upper electrode, of the two upper electrode is the other end of the resistance film, the connection to the other of the upper electrode are each integrally provided, These two connecting portions are connected to the upper surface electrode in each of them at a site that is appropriately spaced along the longitudinal direction of the rectangle of the insulating substrate,
The portion of the resistive film between the connecting portions is
The portion folded back in the longitudinal direction of the insulating substrate and the portion folded back in the short direction of the insulating substrate are continuously spelled.
It is characterized by that.

The chip resistor according to the present invention is as described in claim 2,
“In the first aspect of the present invention, one of the connection portions of the resistive film is adjacent to one of the short side surfaces of the short side surfaces perpendicular to the long side surfaces of the insulating substrate. The other connecting portion is located in a portion adjacent to the other short side surface. "
It is characterized by that.

The chip resistor according to the present invention is as described in claim 3,
“In the first or second aspect of the present invention, both connecting portions of the resistive film are formed with a narrow width .”
It is characterized by that.

Furthermore, the chip resistor according to the present invention is as described in claims 4 and 5,
"In any of the foregoing description claims 1-3, wherein the put the resistive film Ruth Dzura folding Rino some or all are formed by trimming with respect to the resistive film."
It is characterized by that.
In addition to this, the chip resistor according to the present invention, as described in claim 6,
“A portion of the upper surface of the insulating substrate adjacent to one long side surface of the insulating substrate is partially provided with a portion where the upper surface electrodes are not formed. "
It is characterized by that.

Next, the manufacturing method in the present invention is as described in claim 7,
“A step of forming a resistance film on the upper surface of the insulating substrate that is rectangular in plan view; a step of forming a pair of upper surface electrodes on which the connection portions of the resistance film overlap the upper surface of the insulating substrate; A step of forming a terminal electrode on each of the left and right long side surfaces extending in the longitudinal direction of the chip resistor,
The step of forming each upper surface electrode is a step of forming the upper surface of the insulating substrate so as to extend in a band shape along the long side surface in a portion adjacent to the long side surface of the insulating substrate,
The upper surface electrode is formed in a state where the width of the upper surface electrode in the direction along the long side of the resistance film is larger than the width of the connection portion of the resistance film in the direction along the long side of the insulating substrate. And
Forming the resistive film comprises:
The connection to one of the upper electrode of the two upper electrode to one end of the resistance film, provided on the other end of the resistor film in each integrally the connection to the other of the upper electrode, both connections, Connecting to each of the upper surface electrodes at an appropriate distance from each other along the longitudinal direction of the rectangle in the insulating substrate;
Includes a step of forming by the resistive film Wotsu Dzura folding Rio with form,
Before tough Dzura folding rehearsal, the portion that is folded back in the longitudinal direction of the insulating substrate, the lateral direction in the folded Ru portion of the insulating substrate is continuous. "
It is characterized by that.

  With the configuration described in claim 1, soldering when mounting on a printed circuit board or the like is performed on the terminal electrodes formed on the two long side surfaces of the rectangular insulating substrate. The area can be increased, and the thermal stress acting on the soldering portion due to thermal expansion / contraction in the insulating substrate can be reduced, so that it is possible to reliably reduce the possibility that soldering will be removed at the soldering portion.

On the other hand, the resistance film is integrally provided with a connection portion to one of the upper surface electrodes at one end of the resistance film and a connection portion to the other upper surface electrode at the other end of the resistance film. , configure both connections, while connected to the upper surface electrode of each of the sites at a suitable distance from each other along the rectangular longitudinal direction of the insulating substrate, the resistive film, the Ri two zigzag series connection As a result, the length of the current path in the resistive film is set so that the resistance film is formed so as to extend in a direction perpendicular to the longitudinal direction of the rectangle. Since the portion can be increased by the amount connected to each upper surface electrode at an appropriate distance in the longitudinal direction, surge resistance can be improved, and the current path in the resistive film can be increased. resistance The length of the trimming groove engraved on short, because it reduces the number of trimming groove, it is possible to reduce the cost required to engraved trimming groove.

  In addition, since both upper surface electrodes are formed in a strip shape and a connection portion integrated with the resistance film is connected to the belt, heat dissipation from the resistance film through the upper surface electrode and the terminal electrode can be achieved, for example, The chip can be greatly promoted compared to the case where an extension extending in a direction perpendicular to the longitudinal direction of the insulating substrate is integrally provided on the electrode, and the connecting portion integrated with the resistance film is overlapped and connected to the extension. The overload characteristic (STOL evaluation) in the resistor can be reliably improved.

  In this case, as described in claim 2, one connection portion is disposed at a portion adjacent to one short side surface of the insulating substrate, and the other connection portion is disposed at a portion adjacent to the other short side surface. By being positioned, the current path in the resistive film can be made longer by utilizing the rectangular shape of the insulating substrate, and thus the above-described effect can be promoted.

Further, the resistive film, and configured to Ri two zigzag series connection, both ends thereof as described in claim 3, by a connection to both the upper electrode to narrow their current paths Therefore, surge resistance can be further improved.

Moreover, according to the manufacturing method described in claim 7 , a chip resistor having the above-described function can be manufactured at low cost.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 show a chip resistor according to a first embodiment of the present invention.

  The chip resistor 1 according to the first embodiment includes at least an insulating substrate 2 configured as a rectangular chip type having a long side L and a short side W in a plan view with a heat-resistant insulator such as ceramic. A pair of upper surface electrodes 3, 4 formed on both the left and right sides of the rectangular longitudinal direction of the upper surface of the insulating substrate 2, and a rectangular shape between the upper surface electrodes 3, 4 of the upper surface of the insulating substrate 2. A resistive film 5 formed so as to extend in the longitudinal direction, and a terminal electrode for soldering formed on the two long side surfaces 2a, 2b in the rectangle of the insulating substrate 2 so as to extend over the entire length of the long side surfaces 2a, 2b. 6 and 7 and a pair of lower surface electrodes 8 formed to extend along the two long side surfaces 2a and 2b in adjacent portions of the two long side surfaces 2a and 2b of the lower surface of the insulating substrate 2. 9 and the insulating substrate It is constituted by a cover coating 10 by forming glass or a synthetic resin as the upper surface to cover the whole of the resistance film 5.

  Each of the upper surface electrodes 3, 4, the resistance film 5, and the lower surface electrodes 8, 9 is formed by screen printing of the material paste and subsequent firing, and both the terminal electrodes 6, 6 are formed. 7 is formed by application of a material paste and subsequent baking, and the cover coat 10 is formed by screen printing of the material paste and subsequent drying or baking.

  Each of the upper surface electrodes 3 and 4 extends in a band shape along the long side surfaces 2a and 2b in a portion of the upper surface of the insulating substrate 2 adjacent to the long side surfaces 2a and 2b. The terminal electrodes 6 and 7 are connected to the upper surface electrodes 3 and 4 and the lower surface electrodes 8 and 9 so as to overlap each other.

  On the other hand, one end of the resistance film 5 has a narrow connection portion 5a to one of the upper surface electrodes 3 and 4, and the other upper surface electrode has the other end of the resistance film 5. 4 are provided integrally with each other, and both the connecting portions 5a and 5b are arranged along the longitudinal direction of the rectangle of the insulating substrate 2 with respect to the upper surface electrodes 3 and 4 for the respective connecting portions 5a and 5b. It is configured to be overlapped and connected at portions separated from each other by a distance S as appropriate.

In the present embodiment, the portion between the connection portions 5a and 5b at both ends of the resistance film 5 is formed by screen printing and subsequent firing as shown in FIG. The intrusion groove 5c long in the short direction of the insulating substrate 2 and the long intrusion groove 5d in the longitudinal direction of the insulating substrate 2 are engraved by trimming such as laser beam irradiation in the longitudinal direction of the insulating substrate 2. The folded portion and the portion folded in the short direction of the insulating substrate 2 are formed in a continuous spell fold.

One or both of the both entering grooves 5c and 5d also serve as trimming adjustment so that the resistance value in the resistance film 5 falls within a predetermined allowable range by engraving the entering groove. Yes.
In this case, one upper surface electrode 4 of the upper surface electrodes 3 and 4 is made shorter than the other upper surface electrode 3 as shown in FIG. 1 and FIGS. The upper surface electrode 4 is not formed on a portion of the upper surface adjacent to the one long side surface 2b of the insulating substrate 2.

The resistance film 5, as mentioned above, that two zigzag Rio form of series connection is not limited to the method according to the trimming, simultaneously one or a plurality of when the resistance film 5 is screen-printed It is possible to form a zigzag fold by providing a recess groove, or to form a zigzag fold by combining the entering groove provided for screen printing and the entering groove formed by the trimming process.

  Although not shown, the surfaces of the upper surface electrodes 3 and 4 that are not covered with the cover coat 10, the surfaces of the terminal electrodes 6 and 7, and the surfaces of the lower surface electrodes 8 and 9. A plating layer made of a metal having excellent solder bonding properties such as solder is formed.

  The chip resistor 1 having this configuration is soldered by performing soldering to a printed circuit board or the like on the terminal electrodes 6 and 7 formed on the two long side surfaces 2a and 2b of the rectangular insulating substrate 2. The area can be increased, and the thermal stress acting on the soldering portion due to thermal expansion / contraction can be reduced.

  On the other hand, the resistance film 5 is connected to one end of the resistance film 5 at one end of the upper surface electrodes 3, 4, and the other upper surface electrode 4 at the other end of the resistance film 5. The connecting portions 5b are integrally provided, and both the connecting portions 5a and 5b are connected to the respective upper surface electrodes 3 and 4 at a portion separated from each other by a distance S along the longitudinal direction of the rectangle in the insulating substrate 2. Because of the configuration of connection, the length of the current path in the resistance film 5 is set so that both ends of the resistance film 5 are longer than when the resistance film 5 is formed to extend in a direction perpendicular to the longitudinal direction of the rectangle. The connecting portions 5a and 5b provided integrally with each other can be increased by connecting them to the respective upper surface electrodes 3 and 4 at a portion that is appropriately separated by a distance S in the longitudinal direction.

In this case, both the connection portion 5a of the resistor film 5, the portion between 5b, as described above, by configuring the Ri two zigzag series connected, substantially the length of the length of the current path

In particular, the length of the current path, the resistor film 5 as described above, in addition to configuring the Ri two zigzag series connected to constitute two connection parts 5a at both ends, and 5b the slender It can be made longer.

FIG. 4 shows a chip resistor 1 'of a reference example .

  The chip resistor 1 ′ is configured such that one of the connection portions 5 a and 5 b at both ends of the resistance film 5 is connected to one of the short side surfaces extending in a direction perpendicular to the long side surfaces 2 a and 2 b of the insulating substrate 2. 2c and 2d, the other connecting portion 5b is located at a portion adjacent to the other short side surface 2d at the portion adjacent to one short side surface 2c. The distance S between them is increased, and the other configuration is the same as that of the first embodiment.

  According to this configuration, the length of the current path in the resistance film 5 can be further increased as compared with the case of FIGS.

  In manufacturing the chip resistors 1 and 1 'having the above-described configuration, it is preferable to employ the method described below.

  In this manufacturing method, first, as shown in FIG. 5, a pair of upper electrodes 3 and 4 in the form of strips are formed on the upper surface of a rectangular chip-shaped insulating substrate 2 by screen printing and baking of a material paste. As shown in FIG. 6, a pair of lower surface electrodes 8 and 9 extending along the long side surfaces 2a and 2b are formed on the lower surface of the insulating substrate 2 by screen printing and baking of a material paste. As shown in FIG. 7, the connecting portions 5a and 5b, in which the resistance film 5 is integrally provided at both ends of the upper surface of the insulating substrate 2 between the upper surface electrodes 3 and 4, are integrally provided. A step of forming the material paste by screen printing and baking so as to overlap and connect to the upper surface electrodes 3 and 4.

  In each of these three steps, the step of forming the upper surface electrode after the step of forming the lower surface electrodes 8, 9 is performed, and then the step of forming the resistance film 5 is performed. The step of forming the resistance film 5 can be performed after the step of forming 8, 9 and then the upper surface electrodes 3, 4 can be formed.

  In the manufacturing method of the present invention, next, the resistance value of the resistance film 5 is measured on the resistance film 5 by contacting the upper surface electrodes 3 and 4 connected to both ends thereof with an energizing probe as shown in FIG. As shown in the figure, there is a step of trimming adjustment so that the resistance value becomes a predetermined value by engraving the entering grooves 5c and 5d by trimming.

  In the manufacturing method of the present invention, next, as shown in FIG. 9, a cover coat 10 covering the resistance film 5 is formed on the upper surface of the insulating substrate 2 by screen printing of a material paste and subsequent drying or baking. As shown in FIG. 10, the terminal electrodes 6 and 7 are applied to the long side surfaces 2a and 2b of the insulating substrate 2, and the upper surface electrodes 3 and 4 and the lower surface are formed by applying and baking a material paste. A process of forming a part of the electrodes 8 and 9 so as to be partially overlapped with each other, and barrel plating on the surfaces of the upper surface electrodes 3, 4, the terminal electrodes 6, 7 and the lower surface electrodes 8, 9. Forming a metal plating layer.

  Through these steps, the chip resistors 1 and 1 'having the above-described configuration can be manufactured at a low cost.

It is a top view which shows the chip resistor by 1st Embodiment. FIG. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a top view which shows a reference example . It is a perspective view which shows a 1st manufacturing process. It is a perspective view which shows a 2nd manufacturing process. It is a perspective view which shows a 3rd manufacturing process. It is a perspective view which shows a 4th manufacturing process. It is a perspective view which shows a 5th manufacturing process. It is a perspective view which shows a 6th manufacturing process.

Explanation of symbols

1, 1 'Chip resistor 2 Insulating substrate 2a, 2b Insulating substrate long side surface 2c, 2d Insulating substrate short side surface 3, 4 Upper surface electrode 5 Resistive film 5a, 5b Resistive film connecting part 5c, 5d Inlet groove 6 , 7 Terminal electrode 8,9 Bottom electrode 10 Cover coat

Claims (7)

An insulating substrate which is rectangular in plan view, a resistive film formed on the upper surface of the insulating substrate, a pair of upper surface electrode connecting portion of the formed on the upper surface of the insulating substrate Rutotomoni the resistive film overlap, in the insulating substrate In a chip resistor comprising a pair of terminal electrodes formed so as to be electrically connected to the upper surface electrodes on the left and right long side surfaces extending in the longitudinal direction of the rectangle,
Each of the upper surface electrodes is formed on a portion of the upper surface of the insulating substrate adjacent to the long side surface of the insulating substrate , and the upper surface electrode is in a direction along the long side of the resistance film of the upper surface electrode. While the width of the resistor film is longer than the width in the direction along the long side of the insulating substrate in the connection portion of the resistance film, the strip extends long along the side of the long side of the insulating substrate ,
Wherein the one end of the resistor film, wherein the connection to one of the upper electrode, of the two upper electrode is the other end of the resistance film, the connection to the other of the upper electrode are each integrally provided, These two connecting portions are connected to the upper surface electrode in each of them at a site that is appropriately spaced along the longitudinal direction of the rectangle of the insulating substrate,
The portion of the resistive film between the connecting portions is
A chip resistor characterized in that a portion folded in the longitudinal direction of the insulating substrate and a portion folded in the short direction of the insulating substrate are continuously folded .   The connection portion according to claim 1, wherein one of the connection portions of the resistive film is adjacent to one of the short side surfaces of the short side surfaces perpendicular to the long side surfaces of the insulating substrate. A chip resistor, wherein the chip resistor is located at a part, and the other connecting portion is located at a part adjacent to the side surface of the other short side.   3. The chip resistor according to claim 1, wherein both connection portions of the resistance film are formed with a narrow width. In any of the foregoing description claims 1-3, wherein the Ruth Dzura folding Rino all put to the resistive film, chip resistor, characterized in that it is formed by trimming with respect to the resistive film. In any of the foregoing description claims 1-3, wherein the Ruth Dzura folding Rino part put in the resistive film, chip resistor, characterized in that it is formed by trimming with respect to the resistive film.   4. The method according to claim 1, wherein a portion of the upper surface of the insulating substrate adjacent to one long side surface of the insulating substrate is partially provided with a portion not forming the upper surface electrodes. Chip resistor characterized by the above. Forming a resistive film on the upper surface of the insulating substrate which is rectangular in plan view, forming a pair of upper surface electrode connecting portions of the resistive film on the upper surface of the insulating substrate overlap, the rectangle of the said insulating substrate Forming a terminal electrode on each of the left and right long side surfaces extending in the longitudinal direction.
The step of forming each upper surface electrode is a step of forming the upper surface of the insulating substrate so as to extend in a band shape along the long side surface in a portion adjacent to the long side surface of the insulating substrate,
The upper surface electrode is formed in a state where the width of the upper surface electrode in the direction along the long side of the resistance film is larger than the width of the connection portion of the resistance film in the direction along the long side of the insulating substrate. And
Forming the resistive film comprises:
The connection to one of the upper electrode of the two upper electrode to one end of the resistance film, provided on the other end of the resistor film in each integrally the connection to the other of the upper electrode, both connections, Connecting to each of the upper surface electrodes at an appropriate distance from each other along the longitudinal direction of the rectangle in the insulating substrate;
Includes a step of forming by the resistive film Wotsu Dzura folding Rio with form,
Before tough Dzura folding rehearsal, the a portion to be folded back in the longitudinal direction of the insulating substrate, the manufacturing method of the chip resistor, characterized in that the short direction on folded Ru portion of the insulating substrate is continuous.

Images