CN210840198U - Electronic control device - Google Patents

Abstract

The utility model provides an electronic control device, it has the circuit board that the durability is high to fastening member's fastening power. The outermost layer (51) of the circuit board (20) has a lower elastic modulus than an adjacent layer (53) adjacent to the outermost layer (51). The outermost layer (51) has a contact portion (56) that contacts the fastening surface (43) of the fastening member (40). A metal holding body (72) extending in the thickness direction of the circuit board (20) and holding the thickness of the outermost layer (51) is provided to the contact portion (56). One end (78) of the holding body (72) protrudes from the surface (51a) of the outermost layer (51) and abuts against the fastening surface (43) of the fastening member (40). The other end (76) of the holding body (72) reaches at least the boundary (57) between the outermost layer (51) and the adjacent layer (53).

Description

Electronic control device

technical field

The utility model relates to an electronic control device with a circuit board fixed by a fastening part.

Background technique

For example, in an electronic control device mounted on a vehicle, in some devices, a circuit board on which electronic components are mounted is accommodated in a casing. When the temperature in the environment in which the electronic control device is arranged becomes high, the electronic components and the circuit board thermally expand, respectively. The thermal expansion rate of the insulating layer of the circuit board is larger than that of the electronic components. Therefore, when the circuit board is partially expanded, stress is generated in the connection portion of the electronic component with respect to the circuit board, and the connection reliability may be affected. In order to reduce such stress, there is a technique disclosed in Patent Document 1.

The circuit board disclosed in Patent Document 1 is composed of a substrate having a multilayer structure (ie, a plurality of insulating layers). The material of the outermost layer is different from the material of the adjacent layer (adjacent to the outermost layer), and the elastic modulus of the outermost layer is lower than that of the adjacent layer. Therefore, even if it thermally expands, the outermost layer with a low elastic modulus is easily deflected as a whole. The stress caused by the difference in thermal expansion between the circuit board and electronic components is absorbed by the outermost layer.

When housing such a circuit board in a case, the four corners of the circuit board may be fixed to the inside of the case by fastening members such as screws. The screw penetrates the through hole provided in the circuit board, and clamps the circuit board together with the fixing surface of the case.

prior art literature

Patent Document 1: Japanese Patent Laid-Open No. 2018-41800

As mentioned above, the elastic modulus of the outermost layer of the circuit board is low. Therefore, in the outermost layer, the portion that receives the tightening force from the head of the screw is easily compressed. Stress is generated in the boundary portion between the portion compressed by the head of the screw and the portion that is not compressed around the head.

Furthermore, when an electronic control device having this circuit board is mounted on a vehicle, the circuit board repeats expansion and contraction due to temperature changes in the environment, thereby further applying a load to the boundary portion. Even if the elastic modulus of the outermost layer is low, a circuit board having high durability against screw tightening force is desired.

Utility model content

The subject of this invention is to provide the electronic control apparatus which has the circuit board with the high durability of the fastening force with respect to a fastening member.

According to the utility model of the first aspect, there is provided an electronic control device having:

a circuit board, the outermost layer of which has a lower elastic modulus than the elastic modulus of the adjacent layers adjacent to the outermost layer;

a fastening member, which penetrates a through hole provided in the circuit board; and

A fixing surface, which clamps the circuit board together with the fastening surface of the fastening member, and fixes the circuit board, characterized in that:

Among the outermost layers, a contact portion in contact with the fastening surface of the fastening member is provided with a metal-made extending in the thickness direction of the circuit board for maintaining the thickness of the outermost layer. the retainer,

One end of the holder protrudes from the surface of the outermost layer, and is in contact with the fastening surface of the fastening member,

The other end of the holder reaches at least the boundary between the outermost layer and the adjacent layer.

According to Claim 2, it is preferable that the said holding|maintenance body is radially provided centering on the said through-hole.

According to Claim 3, it is preferable that the said holding|maintenance body is a via hole.

According to Claim 4, it is preferable that the other end of the said via hole is located in the boundary between the said outermost layer and the said adjacent layer.

According to the fifth aspect, it is preferable that an annular annular portion surrounding the through hole is provided on a surface of the contact portion in the outermost layer, and the annular portion is provided with the aforementioned annular portion. keep body.

In the utility model of the first aspect, the circuit board of the electronic control device is fixed by the fastening member. The elastic modulus of the outermost layer of the circuit board is lower than the elastic modulus of the adjacent layers adjacent to the outermost layer. The outermost layer has a contact portion that is in contact with the fastening surface of the fastening member. A metal holding body extending in the thickness direction of the circuit board and maintaining the thickness of the outermost layer is provided at the contact portion. One end of the holding body protrudes from the surface of the outermost layer and abuts the fastening surface of the fastening member, and the other end of the holding body reaches at least the boundary between the outermost layer and the adjacent layer.

That is, the contact portion in the outermost layer of the circuit board is reinforced by the metal holder. Therefore, even if the circuit board receives a tightening force from the tightening member, it is not easily compressed, and the thickness of the circuit board is maintained. The elastic modulus of the outermost layer of the circuit board is low, and the durability against the fastening force of the fastening member is high.

In the second aspect of the present invention, the holder is radially provided around the through hole. That is, the holding bodies are uniformly arranged without any offset around the through holes. The tightening force applied to the respective holders from the tightening surfaces of the tightening member can be dispersed.

In the utility model of the third aspect, the holding body is a via hole. Therefore, when forming the conductive pattern for electronic components mounted on the circuit board, the holder can be formed together. The circuit board having the holder can be manufactured while suppressing the processing cost.

In the utility model of the fourth aspect, the other end of the via hole is located at the boundary between the outermost layer and the adjacent layer. Therefore, it is possible to achieve both sufficient reinforcement for the circuit board and reduction of the processing cost of the holder.

In the fifth aspect of the invention, an annular annular portion surrounding the through hole is provided on the surface of the contact portion of the outermost layer. A holding body is provided in the annular portion. The outermost contact portion is reinforced by the annular portion in addition to the holding body. The durability of the circuit board is further improved.

Description of drawings

FIG. 1A is a schematic diagram of an electronic control device of an embodiment.

FIG. 1B is an exploded perspective view of the electronic control device shown in FIG. 1A .

2A and 2B are cross-sectional views taken along line 2a-2a in FIG. 1A.

3A is a diagram illustrating an annular portion provided to surround a through hole of a circuit board and a holding portion provided in the annular portion.

FIG. 3B is a diagram illustrating a holder of Modification 1. FIG.

FIG. 3C is a diagram illustrating a holder of Modification 2. FIG.

4A is a diagram illustrating an electronic control device of a comparative example.

4B is a diagram illustrating the electronic control device of the embodiment.

Label description

10: electronic control device; 20: circuit board; 21: electronic component; 22: first through hole (through hole); 30: housing; 32: support portion; 32a: upper surface (fixed surface); 33: first screw hole; 40: 1st screw (fastening part); 42: head; 43: fastening surface; 51: 1st outer layer (outermost layer); 51a: surface; 52: 2nd outer layer (outermost layer) layer); 52a: surface; 53: inner layer 1 (adjacent layer); 54: inner layer 2 (adjacent layer); 55: inner layer 3; 1 annular portion; 72: first holder; 75: recessed portion; 76: bottom portion (the other end); 77: peripheral wall portion; 78: surface layer portion (one end); 81: second annular portion; 82: second holding body; R1: outer diameter (annulus); R2: outer diameter (head).

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<Example>

Referring to Figures 1A and 1B. The electronic control device 10 has: a circuit board 20 on which electronic components 21 are mounted; a casing 30 capable of accommodating the circuit board 20 ; and a cover 11 for closing the opening of the casing 30 for sealing together with the casing 30 circuit board 20 . The casing 30 is in the shape of a cube, and the upper surface is opened. The casing 30 is provided with an opening 30 a for exposing the connector mounted on the circuit board 20 .

Four support parts 32 capable of supporting the circuit board 20 are provided at the corners of the inner wall 31 of the case 30 . The first screw holes 33 are provided on the upper surface 32 a (fixing surface 32 a ) of each support portion 32 . The first through holes 22 are provided at the corners of the circuit board 20 . Each of the first screws 40 (fastening members 40 ) penetrates the first through holes 22 of the circuit board 20 and can be fastened to the first screw holes 33 .

A flange portion 34 that can be brought into contact with the cover 11 is provided at the edge of the opening of the casing 30 . Second screw holes 35 are provided at the corners of the flange portion 34 . A second through hole 11 a is provided at a corner of the cover 11 . The second screw 12 penetrates the second through hole 11 a of the cover 11 and can be fastened to the second screw hole 35 .

The sealing material 13 is provided on the inner peripheral side of the flange portion 34 of the housing 30 . When the cover 11 is assembled with respect to the case 30, the sealing material 13 also functions as an adhesive material.

Hereinafter, the tightening structure of the 1st screw on the rear left side will be described. In addition, the tightening structure of the other first screws is also the same as the tightening structure on the rear left side.

Referring to Figures 2A and 2B. The circuit board 20 is sandwiched by the fastening surface 43 of the head portion 42 of the first screw 40 and the upper surface 32 a of the support portion 32 . The shaft portion 41 of the first screw 40 penetrates through the first through hole 22 of the circuit board 20 .

The circuit board 20 is a multilayer substrate, and is composed of, for example, five insulating layers. The five insulating layers have: a first outer layer 51 (outermost layer 51 ) which is in contact with the head 42 of the first screw 40 ; and a second outer layer 52 (outermost layer 52 ) which is in contact with the upper part of the support portion 32 surface 32a abutting; first inner layer 53 (adjacent layer 53 ), which is adjacent to first outer layer 51 ; second inner layer 54 (adjacent layer 54 ), which is adjacent to second outer layer 52 ; and The third inner layer 55 is sandwiched between the first inner layer 53 and the second inner layer 54 .

The first inner layer 53 to the third inner layer 55 are composed of inorganic fibers such as glass woven cloth and epoxy resin, respectively. The first outer layer 51 and the second outer layer 52 are composed of inorganic fibers such as glass woven cloth and a thermosetting resin composition, respectively. The thermosetting resin composition contains an epoxy resin and a low elasticizer. The elastic modulus of the first outer layer 51 is lower than the elastic modulus of the first inner layer 53 . Similarly, the elastic modulus of the second outer layer 52 is lower than the elastic modulus of the second inner layer 54 .

The first conductive layer 61 is formed on the surface 51 a of the first outer layer 51 . A second conductive layer 62 is formed at the boundary between the first outer layer 51 and the first inner layer. Similarly, the third conductive layer 63 to the fifth conductive layer 65 are formed at the boundary between the adjacent layers. A sixth conductive layer 66 is formed on the surface 52 a of the second outer layer 52 .

The circuit board 20 is provided with, for example, through holes 23 penetrating the first outer layers 51 to the second outer layers 52 , and blind holes 24 (laser holes 24 ) that enable the first conductive layers 61 and the second conductive layers 62 to conduct electricity. .

Further, on the circuit board 20, for example, a semiconductor chip 25 having solder balls 25a is mounted. In addition, various components including electronic components such as BGA are mounted on the circuit board. A detailed description of the mounted electronic components is omitted.

Referring to Figures 2A and 3A. An annular first annular portion 71 surrounding the first through hole 22 is provided on the surface 51 a of the first outer layer 51 . The first annular portion 71 is a part of the first conductive layer 61 and is formed of copper foil. The outer diameter R1 of the first annular portion 71 is larger than the outer diameter R2 of the head portion 42 of the screw (R1>R2).

Further, the first outer layer 51 is provided with a plurality of first holders 72 for maintaining the thickness of the first outer layer 51 . The first holder 72 is provided on the contact portion 56 of the first annular portion 71 that is in contact with the tightening surface 43 of the head portion 42 of the first screw 40 . The first holding bodies 72 are radially provided around the first through holes 22 .

Similarly, a second annular portion 81 surrounding the first through hole 22 is provided on the surface 52 a of the second outer layer 52 . The second holding body 82 is provided on the second annular portion 81 . The detailed description of the second annular portion 81 and the second holding body 82 is omitted.

Referring to Figures 2A and 2B. The first holder 72 is a blind hole (laser hole) for enabling the first conductive layer 61 and the second conductive layer 62 to conduct electricity. The first holder 72 extends in the thickness direction of the circuit board 20 , and has a bottom portion 76 (the other end 76 ) that is exposed from the bottom of the recessed portion 75 formed by the laser, and a peripheral wall portion 77 that is fastened from the edge of the bottom portion 76 toward the and a surface layer portion 78 (one end 78 ) provided on the upper end of the peripheral wall portion 77 . The bottom portion 76 is a part of the second conductive layer 62 . The surface layer portion 78 is a part of the first conductive layer 61 .

In addition, the first holder 72 may be, for example, a buried hole formed to fill the concave portion 75 . That is, the first holding body 72 only needs to be a member whose one end 78 (surface layer portion 78 ) protrudes from the surface 51 a of the first outer layer 51 and is in contact with the tightening surface 43 of the screw, and the other end 76 (the bottom portion 76 ) ) reaches at least the boundary 57 between the first outer layer 51 and the first inner layer 53 . The other end 76 may reach the inside of the first inner layer 53, for example.

Similarly, the second holder 82 is also the same blind hole (laser hole) as the first holder 72 . Description is omitted.

A modification of the first holding body 72 will be described. Reference numerals are used for the same structures as those in the embodiment, and descriptions thereof are omitted.

Referring to Figure 3B. In Modification 1, a set of holding bodies 79A including three first holding bodies 72 adjacent to each other in the radial direction is provided on the first annular portion 71 with the first through hole 22 as the center. Ten of the set of holding bodies 79A are intermittently provided in the circumferential direction of the first through hole 22 .

Referring to Figure 3C. In Modification 2, the first annular portion 71 is provided with two annular first holding bodies 72B and 72C surrounding the first through holes 22 . The radius of the first holding body 72B is smaller than the radius of the first holding body 72C.

Effects of the embodiment will be described.

Referring to Figure 4A. The above-mentioned annular portions 71 and 81 and holders 72 and 82 are not provided on the circuit board 110 of the electronic control device 100 of the comparative example. The other structures are the same as those of the electronic control device 10 of the embodiment.

The circuit board 110 is sandwiched between the fastening surface 43 of the head portion 42 of the screw and the upper surface 32 a of the support portion 32 . The elastic modulus of the first outer layer 51 of the circuit board 20 is lower than the elastic modulus of the first inner layer 53 . Therefore, the portion of the first outer layer 51 that receives the tightening force from the head portion 42 of the screw is easily compressed. Stress is generated in the boundary 51c between the portion 51a compressed by the head portion 42 of the screw and the portion 51b that is not compressed around the head portion 42 . When the electronic control device 100 having the circuit board 110 is mounted on a vehicle, a temperature change in the environment causes the circuit board 110 to repeat expansion and contraction, thereby further applying stress to the boundary 51c. Like the first outer layer 51, the second outer layer 52 having a low elastic modulus is also compressed from the upper surface 32a of the support portion 32, and stress is generated in the second outer layer.

Referring to Figures 3A and 4B. In the circuit board 20 of the electronic control device 10 of the embodiment, the first outer layer 51 is provided with the first holder 72 for maintaining the thickness of the first outer layer 51 . The first holder 72 is provided in the contact portion 56 of the first outer layer 51 that is in contact with the fastening surface 43 of the first screw 40 .

Therefore, the contact portion 56 that comes into contact with the head portion 42 of the first screw 40 is reinforced by the first holding body 72 . Like the first outer layer 51 , the second holder 82 is provided on the surface 52 a of the second outer layer 52 . As described above, in the circuit board 20 , the elastic modulus of the first outer layer 51 and the second outer layer 52 is low, and the durability against the tightening force of the first screw 40 is high.

Further, an annular first annular portion 71 surrounding the first through hole 22 is provided on the surface 51 a of the first outer layer 51 . Therefore, the contact portion 56 is further strengthened. The durability of the circuit board 20 is further improved. Similarly, since the annular second annular portion 81 surrounding the first through hole 22 is provided on the surface 52a of the second outer layer 52, the second outer layer 52 side is also reinforced.

In addition, the first annular portion 71 is a part of the first conductive layer 61 (see FIG. 2A ). The first holder 72 is a blind hole 24 (laser hole) for enabling the first conductive layer 61 and the second conductive layer 62 to conduct electricity. Therefore, when forming a conductive pattern for the electronic component 21 (refer to FIGS. 1A and 1B ) mounted on the circuit board 20 , the first annular portion 71 and the second holder 82 can also be formed. The second annular portion 81 and the second holding body 82 can be formed in the same manner. The circuit board 20 having the holders 72 and 82 and the annular portions 71 and 81 can be manufactured while suppressing the processing cost.

Further, the bottom 76 (the other end) of the first holder 72 is located at the boundary between the first outer layer 51 and the second outer layer 52 . It is possible to achieve both sufficient reinforcement required for the circuit board 20 and reduction of the processing cost of the first holder 72 .

Referring to Figures 3A and 3B. In addition, the first holding bodies 72 are radially provided around the first through holes 22 . That is, the first holding bodies 72 are uniformly arranged without any deviation with the first through hole 22 as the center. The tightening force applied to each of the first holders 72 from the tightening surface of the head portion 42 of the screw can be dispersed.

In addition, the present invention is not limited to the embodiments and modifications as long as the functions and effects of the present invention can be achieved. A well-known technique can be used for the fastening structure for fixing a circuit board. For example, instead of screws and screw holes, bolts and nuts may be used. A washer may be provided on the fastening surface of the fastening member.

Industrial Availability

The electronic control device of the utility model is suitable for four-wheeled vehicles.

Claims (5)

1. An electronic control device having: a circuit board, the outermost layer of which has a lower elastic modulus than the elastic modulus of the adjacent layers adjacent to the outermost layer; a fastening member, which penetrates a through hole provided in the circuit board; and a fixing surface, which clamps the circuit board together with the fastening surface of the fastening member to fix the circuit board, It is characterized in that, Among the outermost layers, a contact portion in contact with the fastening surface of the fastening member is provided with a metal-made extending in the thickness direction of the circuit board for maintaining the thickness of the outermost layer. the retainer, One end of the holder protrudes from the surface of the outermost layer, and is in contact with the fastening surface of the fastening member, The other end of the holder reaches at least the boundary between the outermost layer and the adjacent layer. 2. The electronic control device according to claim 1, characterized in that, The holder is radially arranged around the through hole. 3. The electronic control device according to claim 2, characterized in that, The retainer is a via. 4. The electronic control device according to claim 3, characterized in that, The other end of the via hole is located at the boundary between the outermost layer and the adjacent layer. 5. The electronic control device according to any one of claims 1 to 4, characterized in that, An annular annular portion surrounding the through hole is provided on the surface of the contact portion in the outermost layer, The holding body is provided in the annular portion.

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