JP2009224725A - Electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component that withstands a test performed under high temperature and high humidity. <P>SOLUTION: The electronic component 1 includes a chip 2 and four external electrodes 3-1 to 3-4. The chip 2 is configured such that: insulating layers 61 to 66 and coil patterns 41, 42, 51 and 52 are alternately laminated on a magnetic substrate 60; and a magnetic substrate 69 is bonded on the uppermost side of the laminated magnetic substrate 60. The electronic component includes thereinside the coils 4 and 5. Extraction end portions 41A and 42A (51A and 52A) of the coil patterns 41 and 42 (51 and 52) face each other on a front rim portion of the insulating layer 62; and extraction end portions 41B and 42B (51B and 52B) thereof face each other on a rear rim portion of the insulating layer 62. The extraction end portion 42A is formed with a horizontal section 43, a first wall 44 and second wall 45. The first wall 44 is a member used for preventing the insulating layer from being swollen largely to the side of the external electrode 3-1; and the second wall 45 is a member used for expanding a connection area to the external electrode 3-1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic component such as a common mode choke coil, and more particularly to the structure of a multilayer electronic component.

Conventionally, in this type of electronic component, the structure of the coil has been devised in order to reduce power consumption and increase the inductance.
As an example, there is an electronic component in which coils are arranged in parallel to reduce resistance and reduce power consumption (see, for example, Patent Document 1).
FIG. 13 is an exploded perspective view showing a conventional electronic component.
In this electronic component 100, a laminated body composed of an insulating layer and a coil is formed on a magnetic substrate 101, and the magnetic substrate 102 is bonded thereon via an adhesive layer. 134 is attached to the outside.
Specifically, a coil body 110 formed by connecting substantially the same coil patterns 111 and 112 in parallel is formed between the insulating layers 211 and 212, and lead-out end portions 113 and 114 of the coil body 110 are connected to the external electrode 131. In addition, the leading end portions 115 and 116 are connected to the external electrode 132. Then, a coil body 120 formed by connecting substantially the same coil patterns 121 and 122 in parallel is formed between the insulating layers 221 and 222, and the leading end portions 123 and 124 are connected to the external electrode 133 and the leading end portion. 125 and 126 are connected to the external electrode 134.
With this configuration, the entire cross-sectional area of the coil bodies 110 and 120 is increased to reduce the resistance value.

JP 2003-133135 A

However, the conventional electronic component has the following problems.
In recent years, with the digitization of automobiles, such electronic components are increasingly used as automobile coils and the like. Electronic components applied to automobiles are subjected to a high load test as to whether or not they can withstand high temperature and high humidity conditions, and high reliability that passes this test is required.
However, in the above-described conventional electronic component, the leading end portions 113 and 114 (115, 116, 123, 124, 125, 126) of the coil body 110 (120) are arranged in parallel above and below the insulating layer 212 (222). It has a structure. For this reason, in the high load test, the insulating layer 212 (222) having a large coefficient of thermal expansion swells toward the external electrodes 131 to 134, and the leading end portions 113 and 114 (115, 116, 123, 124, 125, 126). The external electrodes 131 to 134 are pressed so as to be peeled off. As a result, the connectivity between the external electrodes 131 to 134 and the lead-out ends 113 and 114 (115, 116, 123, 124, 125, and 126) deteriorates, and the lead-out ends 113 and 114 (115, 116, 123, and 124). , 125, 126) increase in DC resistance or disconnection may occur, resulting in frequent occurrence of defective products.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a highly reliable electronic component that can withstand a high temperature and high humidity test.

In order to solve the above problems, the invention according to claim 1 is characterized in that a coil pattern on the first insulating layer and a coil pattern formed on the second insulating layer on the coil pattern are connected in parallel. And a first coil body in which the leading ends of these coil patterns are opposed to each other at the edge of the second insulating layer, and a third insulating layer stacked above the first coil body. The coil pattern and the coil pattern formed on the fourth insulating layer on the coil pattern are connected in parallel, and the leading ends of these coil patterns face each other at the edge of the fourth insulating layer An electronic component comprising a second coil body and a plurality of external electrodes to which the opposing lead ends of the first and second coil bodies are connected, respectively, between the opposing lead ends At the back of the sandwiched insulation layer One or more first wall portions having a predetermined width are provided in parallel to each external electrode connected to these lead-out end portions and perpendicularly connected to the opposite lead-out end portions. A second wall portion having a predetermined length that is vertically connected to each of the external electrodes and the opposing lead-out end portion in a state where the front end portion is exposed from the insulating layer. A plurality of rows are provided, and the back end portions of the plurality of second wall portions are connected to both widthwise side portions of the first wall portion.
With this configuration, when the electronic component is placed in a high-temperature and high-humidity environment, the insulating layer between the opposing drawing end portions of the first and second coil bodies expands toward the external electrode portion side, and presses the external electrode. Then, there is a risk of disconnecting from the opposite drawer end. However, according to the present invention, in the inner part of the insulating layer sandwiched between the opposing lead ends, the external electrodes connected to the lead ends are connected in parallel to and perpendicular to the opposing lead ends. Since one or more first wall portions having a predetermined width are provided, the length of the insulating layer that expands toward the external electrode is the length of the insulating layer that exists between the external electrode and the first wall portion. Very short. For this reason, the expansion of the insulating layer is very small, and does not expand so much as to press the external electrode and remove it from the lead end.
In the present invention, since the plurality of rectangular contact portions are constituted by the lead-out end portions and the plurality of second wall portions, the connection area with the external electrode is increased correspondingly, and these lead-out end portions Can be firmly connected to the external electrode.

As described above in detail, according to the electronic component of the present invention, even when placed in a high-temperature and high-humidity environment, the expansion of the insulating layer in the portion sandwiched between the opposing drawer ends is very small, and the external electrode is Since it is not removed from the end of the drawer, there is an excellent effect that high connection reliability can be obtained even in a high temperature and high humidity test.
Further, since the connection area with the external electrode is increased and the lead-out end portion and the external electrode can be firmly connected, the connection reliability can be further improved.

  The best mode of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of an electronic component according to one embodiment of the present invention, and FIG. 2 is an external view of the electronic component showing external electrodes separately.
As shown in these drawings, the electronic component 1 of this embodiment is a common mode choke coil, and includes a chip body 2 and four external electrodes 3-1 to 3-4.

As shown in FIG. 1, the chip body 2 is formed by alternately laminating a plurality of insulating layers and coil patterns on a magnetic substrate 60, and the magnetic substrate 69 is bonded to the top through adhesive layers 67 and 68. The coil body 4 as the first coil body and the coil body 5 as the second coil body are included inside.
Specifically, an insulating layer 61 as a first insulating layer is laminated on the magnetic substrate 60, and the coil pattern 41 is formed on the insulating layer 61. Further, an insulating layer 62 as a second insulating layer is laminated on the coil pattern 41, a coil pattern 42 is formed on the insulating layer 62, and an insulating layer 63 is laminated on the coil pattern 42. The coil patterns 41 and 42 are electrically connected through a via hole 62 a provided in the insulating layer 62. Thereby, the coil body 4 of the parallel spiral which consists of the coil patterns 41 and 42 is formed in an insulating layer.
Further, an insulating layer 64 as a third insulating layer is laminated on the insulating layer 63, and the coil pattern 51 is formed on the insulating layer 64. An insulating layer 65 as a fourth insulating layer is laminated on the coil pattern 51, a coil pattern 52 is formed on the insulating layer 65, and an insulating layer 66 is laminated on the coil pattern 52. The coil patterns 51 and 52 are electrically connected through a via hole 65 a provided in the insulating layer 65. Thereby, the coil body 5 of the parallel spiral which consists of the coil patterns 51 and 52 is formed in an insulating layer.

As shown in FIG. 2, the coil bodies 4 and 5 as described above are provided with lead-out ends whose tips are exposed from the side surfaces of the chip body 2.
Specifically, as shown in FIG. 1, the coil pattern 41 of the coil body 4 is provided with a leading end 41 </ b> A drawn from the outside of the coil pattern 41 and a leading end 41 </ b> B drawn from the inside. The pattern 42 is provided with a leading end 42A drawn from the outside of the coil pattern 42 and a leading end 42B drawn from the inside. The leading end portions 41A and 42A face each other at the front edge portion (the edge portion on the near side in FIG. 1) of the insulating layer 62, and the leading end portions 41B and 42B face each other at the trailing edge portion (see FIG. 1). Opposite edges at the back).
Similarly, the coil pattern 51 of the coil body 5 is provided with a leading end 51 </ b> A that is drawn from the outside of the coil pattern 51 and a leading end 51 </ b> B that is drawn from the inside. A pull-out end 52A drawn from the inside and a pull-out end 52B drawn from the inside are provided. The leading end portions 51A and 52A face each other at the front edge portion of the insulating layer 65, and the leading end portions 51B and 52B face each other at the rear edge portion of the insulating layer 65.

Here, the structure of each drawer end will be described in detail.
FIG. 3 is a perspective view showing a leading end facing the edge of the insulating layer, FIG. 4 is a plan view showing through the coil pattern 52 and subsequent parts in FIG. 1, and FIG. FIG. 6 is a cross-sectional view taken along the line AA, and FIG. 6 is a cross-sectional view taken along the line BB in FIG.
As shown in FIG. 4, in the electronic component 1 of this embodiment, four sets of opposing drawer end portions 41A, 42A, 41B, 42B, 51A, 52A, 51B, 52B are arranged on the front surface and the rear surface of the chip body 2. Although the structure of the drawer end portions 41B, 42B, 51A, 52A, 51B, and 52B is the same as that of the drawer end portions 41A and 42A, the structure of the drawer end portions 41A and 42A is shown in FIG. Display only for.

As shown in FIG. 3, the drawer end portion 41 </ b> A is formed in a horizontal pattern, but the drawer end portion 42 </ b> A has a shape having a comb-like horizontal portion 43.
And the 1st wall part 44 and the 2nd wall part 45 are formed in the insulating layer 62 between such drawer | drawing-out edge part 41A, 42A.
Specifically, as shown in FIGS. 5 and 6, the first wall portion 44 is a member for preventing the insulating layer 62 from greatly expanding toward the external electrode 3-1, and has a leading end portion. In a state of being sandwiched between 41A and 42A, the insulating layer 62 is disposed at a depth L from the front surface of the insulating layer 62. Further, as shown in FIG. 6, the first wall portion 44 is parallel to the external electrode 3-1 and is connected perpendicularly to the lead-out end portions 41 </ b> A and 42 </ b> A.
On the other hand, the second wall portion 45 is a member for expanding the connection area with the external electrode 3-1, and is sandwiched between the leading end portions 41A and 42A as shown in FIGS. The first wall portion 44 is disposed closer to the external electrode 3-1, and the tip end portion is exposed from the insulating layer 62 to the external electrode 3-1 side. Thereby, the front end portion of the second wall portion 45 is flush with the horizontal portion 43 of the leading end portion 42A and the leading end portion of the leading end portion 41A on the front surface of the insulating layer 62. Further, as shown in FIG. 5, the second wall portion 45 is connected to the external electrode 3-1 and also to the lead-out end portions 41 </ b> A and 42 </ b> A.
The six second wall portions 45 are arranged in the width direction of the external electrode 3-1 at an interval of the width W, and are connected to the three first wall portions 44 every other one. Specifically, the back end portions of the first and second second wall portions 45 from the left in the drawing are connected to both side portions in the width direction of one first wall portion 44, and similarly, the third and fourth portions are connected. The back end portions of the second and second wall portions 45 and the back end portions of the fifth and sixth second wall portions 45 are respectively connected to both sides in the width direction of the first wall portion 44.

  As shown in FIG. 2 and the like, the external electrodes 3-1 to 3-4 are exposed on the front surface (front surface in FIG. 2) and the rear surface of the chip body 2 and lead-out ends 41 </ b> A, 42 </ b> A, 41 </ b> B, 42B, 51A, 52A, 51B, 52B, and the second wall 45 are connected to each other. At this time, as shown in FIG. 5, since the contact portion constituted by the lead end portions 41A and 42A and the second wall portion 45 has a rectangular cross section, the lead end portions 41A and 42A and the external electrodes The connection area with 3-1 etc. is extremely large.

Next, a method for manufacturing the electronic component 1 will be briefly described.
First, an Ag film layer is formed on a polyimide resin insulating layer 61 laminated on the magnetic substrate 60 by a film forming technique such as a thin film forming method such as sputtering or vapor deposition, or a thick film forming method such as screen printing. The coil pattern 41 having the leading end portions 41A and 41B is formed using a series of photolithography techniques such as resist coating, exposure, development, and etching. Subsequently, a photosensitive polyimide resin was applied on the coil pattern 41, and exposure and development were performed to form an insulating layer 62 having a via hole 62a. On the insulating layer 62, lead-out end portions 41B and 42B were provided. The coil body 4 is formed by sequentially stacking the coil pattern 42 and the insulating layer 63.
Thereafter, similarly to the coil body 4, the insulating layers 64 to 66 and the coil patterns 51 and 52 are alternately stacked on the insulating layer 63 to form the coil body 5.
Next, adhesive layers 67 and 68 of thermosetting polyimide resin are formed on the insulating layer 66 and the magnetic substrate 69 is bonded together, and then heated and pressurized in a vacuum or in an inert gas and cooled. A wafer in which the insulating layers 61 to 66 and the coil bodies 4 and 5 are sandwiched between the magnetic substrates 60 and 69 can be formed.
Then, after dicing the wafer into the chip body 2, external electrodes 3-1 and 3-2 are formed on the side surfaces of the chip body 2 so as to be in contact with the lead-out ends 41A, 42A, 41B and 42B of the coil body 4. The external electrodes 3-3 and 3-4 are formed on the side surfaces of the chip body 2 so as to be in contact with the lead-out end portions 51A, 52A, 51B, and 52B of the coil body 5.
Specifically, an Ag film is formed on portions corresponding to the lead end portions 41A, 42A, 41B, 42B and 51A, 52A, 51B, 52B by applying a conductive paste containing Ag, sputtering or vapor deposition of Ag, or the like. To do. Then, a metal film such as Ni, Sn—Pb is formed on the Ag film by wet electrolytic plating or the like.
Thus, the electronic component 1 provided with the external electrodes 3-1, to 3-4 on the chip body 2 can be manufactured.

In this embodiment, Ag is used as a material for forming the coil patterns 41, 42, 51, 52 of the coil bodies 4, 5. However, metals such as Cu, Pd, and Al, which are excellent in conductivity, and alloys thereof can be used.
Moreover, photosensitive polyimide resin was used as the insulating layers 61-66. However, in addition to the polyimide resin, various resin materials such as epoxy resin and benzocycloptene resin, glass such as SiO2, glass ceramics, dielectrics, and the like can be used.
The magnetic substrates 60 and 69 were made of ferrite having a relative permeability of 400 or more.
Further, the external electrodes 3-1 to 3-4 are formed of a thin film Ag and a Ni film, but a metal film such as Ni, Sn-Pb or the like on a thin film such as Ab-Pd, Cu, NiCr or NiCu. It can also be formed using.

By the way, the lead end portions 41A, 42A, 41B, 42B and 51A, 52A, 51B, 52B of the coil bodies 4, 5 are formed in the above manufacturing method, but these are the main parts of this embodiment. The formation process will be described in detail.
FIG. 7 is a partial cross-sectional view showing the process of forming the drawer end.
First, as shown in FIG. 7A, the insulating layer 61 (or insulating layer 64) is laminated on the magnetic substrate 60 (or insulating layer 63). Thereafter, an Ag film layer is formed on the insulating layer 61 (or the insulating layer 64) by using a thin film forming method such as sputtering or vapor deposition. Then, as shown in FIG. 7B, a flat lead end 41A (or lead end 41B, 51A, 51B) is formed using a series of photolithography techniques such as resist coating, exposure, development and etching. Form. Further, as shown in FIG. 7C, a photosensitive polyimide resin insulating layer 62 (insulating layer 65) is laminated on the leading end 41A (or the leading end 41B, 51A, 51B). As shown in FIG. 4D, three rectangular via holes 62b (or via holes 65b) having a width W and a length L that open in the vertical direction and the front side of the figure are formed by using a photolithography technique.
The number of via holes 62b (65b) is not limited to three, but is preferably between 1 and 5. Further, the width W of the via hole 62b (65b) is preferably about 1/3 to 1/10 of the width (the distance in the left-right direction in FIG. 3) of the leading end portion 42A (42B, 52A, 52B), and the length L is It is preferable that the length is equal to or more than ½ of the length (the distance in the front-rear direction in FIG. 3) of the leading end 42A (42B, 52A, 52B).
Thereafter, an Ag film layer is formed on the insulating layer 62 (or the insulating layer 65) by using a thin film forming method. Then, as shown in FIG. 7E, using the photolithography technique, the horizontal portion 43, the first wall portion 44, and the second portion of the leading end portion 42A (or the leading end portions 42B, 52A, and 52B) are used. A wall 45 is formed.
In this way, the lead end portions 41A, 42A, 41B, 42B, 51A, 52A, 51B, 52B, the first wall portion 44 and the second wall portion 45 of the coil bodies 4, 5 are connected to the insulating layers 62, 65. Can be formed on the edge.

Next, operations and effects of the electronic component 1 of this embodiment will be described.
FIG. 8 is a cross-sectional view showing a conventional drawer end, and FIG. 9 is a cross-sectional view for explaining the operation of the conventional drawer end.
First, as shown in FIG. 8, the drawer end portion 42A is formed flat like the drawer end portion 41A to constitute a conventional drawer end portion, and the electronic component having such drawer end portions 41A and 42A is heated at a high temperature. Placed in a humid environment. Then, since the thermal expansion coefficient of the insulating layers 61 to 63 of polyimide resin is much larger than the thermal expansion coefficient of the lead ends 41A and 42A made of Ag, as shown in FIG. 9, the external electrode 3-1 side The insulating layer 62 expands longer than the leading end portions 41A and 42A. The elongation due to the expansion of the insulating layer 62 corresponds to the entire length of the insulating layer 62 between the external electrodes 3-1 and 3-2. For this reason, the insulating layer 62 extends long in the direction of the external electrode 3-1 (3-2), and the pressing force F by the insulating layer 62 is applied to the external electrode 3-1, as indicated by an arrow. As a result, the external electrode 3-1 may be deformed and detached from the leading end portions 41A and 42A.

On the other hand, in the electronic component 1 of this embodiment, as shown in FIG. 6, the three first wall portions 44 are disposed at the back by a distance L from the front surface of the insulating layer 62, and the second The back end portions of the wall portion 45 are connected to each other. For this reason, since the insulating layer 62 expands corresponding to the distance L between the first wall portion 44 and the external electrodes 3-1 and 3-2 at the time of expansion, the expansion is the same as the conventional one shown in FIG. It is extremely short compared to the elongation of the insulating layer to which the drawing end of the mold is applied. As a result, the pressing force by the insulating layer 62 is hardly applied to the external electrode 3-1, and as a result, there is no possibility that the external electrode 3-1 is detached from the leading end portions 41A and 42A.
Further, in this embodiment, as shown in FIG. 5, the lead-out end portions 41A and 42A and the second wall portion 45 are formed in a rectangular cross section, thereby greatly increasing the connection area with the external electrode 3-1. Accordingly, the lead-out end portions 41A and 42A and the external electrode 3-1 are firmly connected.

The inventors conducted the following experiment in order to confirm this effect.
FIG. 10 is a diagram showing experimental results.
The magnetic substrates 60 and 69 having a relative magnetic permeability of 600 were used, and the horizontal, vertical, and thickness were set to 1.0 mm or less, 2.0 mm or less, and 25 μm to 350 μm, respectively. And the thickness of the insulating layers 61-66 and the coil bodies 4 and 5 except these magnetic substrates 60 and 69 was set to 40 micrometers. Further, as the insulating layers 61 to 66, an insulator having a relative dielectric constant of 3 was used. Furthermore, the line length of the coil bodies 4 and 5 was set to 8.5 mm to 11 mm, and the line width and the line interval of each coil pattern 41 (42, 51, 52) were set to 23 μm and 15 μm, respectively.
In this experiment, first, an electronic component having the above-mentioned dimensions and the above-described material and having the conventional drawer end shown in FIG. 8 is placed in a high-temperature and high-humidity environment at a temperature of 70 ° C. and a humidity of 95%. The sample was left for 100 hours to 1000 hours, and the occurrence rate of defective products was examined.
Then, as shown by the defective product generation curve S1 in FIG. 10, no defective product was generated even when left in such a high temperature and high humidity environment for up to about 500 hours. The generation rate of non-defective products increased rapidly, reaching about 55% in 1000 hours.
Next, the electronic component 1 of this example was made with the above-described dimensions and materials, and was left in a high-temperature and high-humidity environment with a temperature of 70 ° C. and a humidity of 95% for 100 hours to 1000 hours. The incidence was examined.
Then, as shown by the defective product generation curve S2 of FIG. 10, it was confirmed that the defective product occurrence rate was extremely good, “zero” between 100 hours and 1000 hours, and the expected effect could be obtained. .

In addition, this invention is not limited to the said Example, A various deformation | transformation and change are possible in the range of the summary of invention.
For example, in the above embodiment, as shown in FIGS. 5 and 6, the horizontal portion 43 is provided at the drawer end portion 42 </ b> A, and the three first wall portions 44 are connected to the back of the six pairs of second wall portions 45. Although the example which connected every other edge part was shown, the 1st wall part 44 is enough if the back end parts of the 2nd wall part are connected. Accordingly, as shown in FIGS. 11 and 12, six second wall portions 45 each having a length L are arranged in a row between one drawing end portion 42A and one drawing end portion 41A. An electronic component that includes a drawer end having a configuration in which the wall 44 is connected to all the rear ends of the six second walls 45 is also included in the scope of the present invention.

It is a disassembled perspective view of the electronic component which concerns on one Example of this invention. It is an external view of the electronic component which isolate | separates and shows an external electrode. It is a perspective view which shows the drawer | drawing-out edge part which opposes at the edge part of an insulating layer. FIG. 2 is a plan view showing a coil pattern and subsequent portions in FIG. It is arrow AA sectional drawing of FIG. It is arrow BB sectional drawing of FIG. It is a fragmentary sectional view showing a formation process of a drawer end part. It is sectional drawing which shows the drawer | drawing-out edge part of the conventional type. It is sectional drawing for demonstrating the effect | action which the conventional drawer | drawing-out edge part shows. It is a diagram which shows an experimental result. It is a front sectional view showing one modification of a drawer end. It is a sectional side view of the modification shown in FIG. It is a disassembled perspective view which shows the electronic component of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic component, 2 ... Chip body, 3-1-3-4 ... External electrode, 4, 5 ... Coil body, 41, 42, 51, 52 ... Coil pattern, 41A, 41B, 42A, 42B, 51A, 51B , 52B, 52B ... drawer end, 43, 43 '... horizontal, 44, 44' ... first wall, 45 ... second wall, 60, 69 ... magnetic substrate, 61-66 ... insulating layer, 62a, 65a ... via hole, 62b, 65b ... rectangular via hole, 67, 68 ... adhesive layer.

Claims (1)

A coil pattern on the first insulating layer and a coil pattern formed on the second insulating layer on the coil pattern are connected in parallel, and the leading ends of these coil patterns are the second A first coil body facing at an edge of the insulating layer;
The coil pattern on the third insulating layer stacked above the first coil body and the coil pattern formed on the fourth insulating layer on the coil pattern are connected in parallel, and these A second coil body in which the drawn ends of the coil pattern face each other at the edge of the fourth insulating layer;
An electronic component comprising a plurality of external electrodes respectively connected to opposing leading ends of the first and second coil bodies,
In the inner part of the insulating layer sandwiched between the opposing lead-out end portions, a predetermined width connected in parallel to each external electrode connected to these lead-out end portions and perpendicular to the opposing lead-out end portions Providing one or more first walls,
A predetermined length that is vertically connected to each external electrode and the opposite leading end in an insulating layer sandwiched between the facing leading ends, with the tip portion exposed from the insulating layer. The second wall portions are arranged in a plurality of rows, and the back end portions of the plurality of second wall portions are connected to both sides in the width direction of the first wall portion,
An electronic component characterized by that.

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