JP2006211776A - Electrical junction box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of damage such as cracking to a fixed portion between an electronic component and a substrate by simple means. <P>SOLUTION: A retaining member 61 for preventing vibration of the electronic component 13 is provided on a case 20 side, therefore, the retaining member 61 can be formed into a simple structure and high flexibility of circuit design can be ensured without an increase in the size of a circuit control substrate 11. Moreover, the retaining member 61 is a sheet-like rubber member bonded to the bottom face of a cover 40, therefore, the pressure generated at the electronic component 13 by the retaining member 61 is adjusted so as to be an excessive pressure. Furthermore, the top face of the electronic component 13 is face-retained, thus evenly retaining the whole top face. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrical junction box.

The thing of patent document 1 is known as an electrical junction box mounted in a vehicle etc. This electrical connection box is a case in which a circuit structure including an electronic circuit board having a predetermined conductive path formed on the upper surface and an electronic component such as a semiconductor switching element mounted on the electronic circuit board is accommodated in a case. is there. The electronic component is fixed on the substrate by soldering terminals derived from the side surface of the main body.
Japanese Patent Laid-Open No. 11-17318 Japanese Utility Model Publication No. 5-62068 JP 2002-217343 A

  By the way, in such an electrical connection box mounted on a vehicle or the like, stress is generated in the solder portion that fixes the electronic component and the substrate due to vibration or the like accompanying traveling of the vehicle. If the stress is greater than the strength of the solder, damage such as cracking or cracking in the solder portion occurs. In order to avoid this, a technique has been proposed in which vibration preventing means such as a hardener or a support member for supporting the electronic component is installed on the circuit board.

  However, it is difficult to fix the vibration preventing means to a substrate that has high density of electronic components and circuits and requires delicate handling, and the manufacturing process becomes complicated. In addition, since a new space is required for the circuit board, the circuit board becomes larger, or the means for applying the means to the circuit board whose size is limited reduces the degree of freedom in circuit design. Problems arise.

  The present invention has been completed based on the above-described circumstances, and an object thereof is to prevent damage such as cracks from occurring in a fixing portion between an electronic component and a substrate by simple means.

  As means for achieving the above object, the invention of claim 1 is an electrical junction box comprising a circuit board on which an electronic component is mounted and a case part for housing the circuit board, wherein the case part Includes a lid that covers the circuit board from the side on which the electronic component is mounted, and the electronic part abuts on the surface of the electronic component opposite to the side facing the previous circuit board. It is characterized in that a pressing member is provided to press down.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the pressing member is an elastic member.

  The invention of claim 3 is characterized in that, in the invention of claim 2, the elastic member is a cushioning material lined on the inner surface of the lid.

The invention according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, the pressing member is made of a heat conductive material.
The invention of claim 5 is characterized in that, in the invention according to any one of claims 1 to 4, the lid portion is made of a heat conductive material.

The invention according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 3, the pressing member is made of a heat insulating material.
The invention of claim 7 is characterized in that, in the invention of any one of claims 1 to 3, the lid portion is made of a heat insulating material.

<Invention of Claim 1>
According to the first aspect of the present invention, since the pressing member for preventing the vibration of the electronic component is provided on the case side, the pressing member can be simplified in structure and without increasing the size of the circuit board. The degree of freedom in circuit design can also be secured.

<Invention of Claim 2>
According to the invention of claim 2, the pressing member for pressing the electronic component is an elastic member. According to such a configuration, since the pressing force generated on the electronic component by the pressing member is adjusted so as not to be excessive pressing force, the fixing portion between the electronic component and the circuit board is cracked by the pressing force by the pressing member. It is possible to prevent the occurrence of damage.

<Invention of Claim 3>
According to the invention of claim 3, the pressing member is a cushioning material such as a rubber material or a sponge material lined on the inner surface of the lid portion. According to such a configuration, the upper surface of the electronic component (the surface on the side facing the lid) is planarly held, and the entire upper surface can be pressed evenly. Further, the contact with the electronic component is softened, and it is possible to avoid scratching the surface of the electronic component due to friction between the pressing member and the electronic component.

<Invention of Claims 4 and 5>
According to invention of Claim 4 and Claim 5, the pressing member or the cover part is formed of the heat conductive material. According to such a configuration, heat generated from the electronic component is dissipated to the outside through the pressing member and the lid, so that heat dissipation is improved.
<Invention of Claims 6 and 7>
According to the sixth and seventh aspects of the present invention, when the temperature outside the lid is high, the holding member or the lid is made of a heat insulating material to prevent heat transfer from the outside of the lid and increase the internal temperature. Can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows an external perspective view of the electrical junction box 1 of the present embodiment, and FIG. 2 shows an exploded perspective view of the electrical junction box 1 of the present embodiment.
In the following, each component will be described with the upper side in FIG. 1 as the upper side, the lower side as the lower side, the left front side as the front, and the right back side as the rear.

The electrical junction box 1 of the present embodiment includes a circuit structure 10 and a case 20 (corresponding to a case portion of the present invention) that accommodates the circuit structure 10.
The circuit structure 10 accommodated in the electrical junction box 1 includes a control circuit board 11 (corresponding to the circuit board of the present invention), a bus bar board 12 attached to the control circuit board 11, and a top surface side. It is comprised with the electronic components 13, such as the mounted relay.

  The control circuit board 11 has an outer shape in which a corner on the left front end side in a rectangle is dropped, and conductive paths (not shown) are formed in a predetermined pattern on both front and back surfaces. Further, a through hole 14 for inserting the male terminal 31 of the PCB connector 30 is formed at the front end of the control circuit board 11.

  The bus bar substrate 12 is attached to the lower surface of the control circuit substrate 11 through a thin adhesive sheet having insulating properties. The bus bar substrate 12 is formed by punching a metal plate having excellent conductivity, forms a predetermined conductive path that becomes a power circuit, has an outer shape substantially aligned with the control circuit substrate 11, and has a plurality of edges from its rear edge. A bus bar 12A is protruded. Among the bus bars 12A, the bus bar 12A arranged over the region on the substantially left side except for one at the left end when viewed from the front is bent at a right angle twice on the surface side of the control circuit board 11 so that the front end is rearward. It protrudes horizontally. The remaining bus bar 12A is further bent twice, so that the tip protrudes horizontally toward the front.

  The electronic component 13 mounted on the circuit structure 10 includes a cuboid main body 13A as a whole and a plurality of terminals 13B protruding from the lower surface of the main body 13A (see also FIG. 5). The terminals 13B are connected to the control circuit board 11 by soldering or connected to the bus bar board 12 through through holes provided in the control circuit board 11 (soldering part 15).

  The PCB connector 30 assembled on the front end side of the circuit structure 10 includes a housing 32 made of a synthetic resin that is horizontally long and opened on the front surface. The male terminal 31 bent into an L shape is formed in the housing 32. One end is projected into the opening and the other end is projected downward through the back wall and is mounted in two rows (see also FIG. 4). The downward projecting ends of the male terminals 31 are inserted into the through holes 14 opened in the control circuit board 11 from above and connected by soldering on the lower surface side. Moreover, the mounting leg 33 formed on the lower surface of the PCB connector 30 is applied to the upper surface of the circuit component 10 and is screwed from the lower surface side. On the rear surface of the PCB connector 30, there is provided a locking piece 34 formed in an L shape that protrudes rearward and rises upward.

  In addition, the case 20 includes a frame body 21 having a shape surrounding the circuit structure 10, a heat dissipation plate 22 attached to the lower side of the frame body 21, and a cover 40 ( Corresponding to the lid portion of the present invention).

  The frame body 21 is made of an insulating material such as a synthetic resin, and is formed in a shape that allows the control circuit board 11 and the bus bar board 12 to be fitted almost tightly inside. And the circuit structure 10 in which the PCB connector 30 is mounted is assembled | attached with respect to this frame 21 from upper direction. Lock protrusions 23 are provided on the left and right side walls of the frame body 21.

  The heat radiating plate 22 mounted on the lower side of the frame body 21 is formed in a shape substantially the same as the outer shape of the frame body 21 by a metal plate such as aluminum having a high thermal conductivity, and is disposed on the lower surface side of the frame body 21. It is assembled so as to close the opening, and is attached to the lower surface of the bus bar substrate 12 via an insulating adhesive. The front side of the heat radiating plate 22 bulges downward to avoid interference with the end of the male terminal 31 mounted on the PCB connector 30 that protrudes to the lower surface side of the control circuit board 11. An escape recess 24 is formed. Further, from the rear edge of the heat radiating plate 22, the mounting piece 25 is formed so as to escape obliquely downward. The electrical junction box 1 is attached to the vehicle panel P through the attachment piece 25 in a vertical orientation with the PCB connector 30 facing downward (see also FIG. 4). A potting agent (not shown) such as gel is put into the frame body 21 and the surface of the control circuit board 11 is covered with the potting agent to ensure waterproofness.

  The cover 40 assembled on the upper side of the frame body 21 is made of synthetic resin, and is formed to have a size covering almost the entire upper surface (the surface on which the electronic component 13 is mounted) of the control circuit board 11. On the other hand, it is mounted so as to cover the opening on the upper surface side. On the front end side of the cover 40, a high-level portion 41 is formed to cover the rear surface side of the PCB connector 30. On the other hand, a fitting recess 42 is provided on the rear end side for fitting and releasing a part of the fuse box 50. The flexure-deformable lock pieces 43 provided on the left and right side surfaces of the cover 40 are engaged with the lock projections 23 provided on the frame body 21 and are also provided on the left and right ends of the rear end side of the cover 40. The mounting recess 44 is screwed to the frame body 21.

  A pair of projecting walls 45 are provided on the lower surface of the front end portion of the cover 40, that is, the high position portion 41. The pair of projecting walls 45 includes a front projecting wall 45A formed along the front end edge and the front projecting wall. The rear projecting wall 45B is formed substantially parallel to the rear side with a predetermined distance from 45A. A locking groove 46 having a predetermined depth is formed between the protruding walls 45 </ b> A and 45 </ b> B, and a locking piece 34 formed on the PCB connector 30 is inserted into the locking groove 46. The rear projecting wall 45B is reinforced by the reinforcing rib 47. Further, a drainage slope portion 48 is provided at a position corresponding to the fitting recess 42 in which the fuse box 50 is fitted and released at the rear edge of the cover 40, and a plurality of support plates 49 are provided on the upper surface of the drainage slope portion 48. They are arranged side by side.

  The fuse box 50 assembled on the rear end side of the cover 40 is made of synthetic resin, and is formed in a horizontally long shape so as to cover the rear surface side of the frame body 21 over the entire length. At both ends in the length direction, connector portions 51 opened to the front surface are provided, a fuse mounting portion 52 is provided on the left side when viewed from the front between the connector portions 51, and a terminal accommodating portion 53 is provided on the right side. It has been. A bus bar 12A with the tip facing backward is press-fitted to the fuse mounting portion 52, and a bus bar 12A with the tip facing forward is accommodated in the connector portion 51 and the terminal accommodating portion 53. A necter 54 can be coupled to the front surface of the region extending between the fuse mounting portion 52 and the terminal accommodating portion 53. The fuse box 50 is fitted with a fuse 55 from the rear side.

  The connector 54 assembled to the fuse box 50 has a horizontally long shape extending along the length direction of the fuse box 50. Then, the connection terminal and the bus bar 12 </ b> A projecting from the fuse mounting portion 52 and the terminal accommodating portion 53 of the fuse box 50 are inserted into the fitting portion 56 opened to the front surface of the connector 54.

  Now, the lower surface of the cover 40 will be described in detail. 3 is a perspective view of the cover 40 having the pressing member 61 as viewed from below, FIG. 4 is a side sectional view of the electrical junction box 1 attached to the vehicle panel P, and FIG. The partial expanded sectional view showing the state in which the pressing member 61 affixed on the lower surface of 40 was contact | abutted on the upper surface of the electronic component 13 was shown.

  On the lower surface of the cover 40, in order to prevent “sinking” and “sledge” at the time of resin molding, the cover 40 is thinned and ribs 60 are arranged. The rib 60 has a lattice shape as a whole. However, the rib 60 is not provided in a region facing the electronic component 13 on the lower surface (inner surface) of the cover 40 so that a gap is formed between the lower surface of the assembled cover 40 and the upper surface of the electronic component 13. It has become. And in this area | region, as shown in FIG. 3, the pressing member 61 is provided. The pressing member 61 is formed of a heat conductive rubber. The pressing member 61 has substantially the same thickness as the gap formed between the lower surface of the cover 40 and the upper surface of the electronic component 13 and is formed in a sheet shape that extends to cover the upper surface of the plurality of electronic components 13 over the entire surface. Has been. The pressing member 61 is attached to the lower surface of the cover 40 with an adhesive or the like.

Next, the operation and effect of the present embodiment configured as described above will be described.
When the cover 40 is assembled, as shown in FIGS. 4 and 5, the pressing member 61 comes into contact with the upper surface of the electronic component 13 (the surface opposite to the side facing the control circuit board 11 in the electronic component 13). The part 13 is pressed and held. As a result, even if the electrical connection box 1 vibrates, a large stress due to vibration or the like is not generated in the soldering portion 15 between the electronic component 13 and the boards 11 and 12. It is possible to prevent the occurrence of damage.

  The pressing member 61 is provided on the cover 40 side. Here, if the holding member 61 is provided on the control circuit board 11 side, the electronic parts 13 and the conductive paths are arranged in the control circuit board 11 at a high density and there is no extra space. The new space must be secured. Then, it becomes necessary to enlarge the control circuit board 11, otherwise there arises a problem that the degree of freedom in circuit design is lowered. Further, it is difficult to attach the pressing member 61 to the control circuit board 11 that requires delicate handling, and the manufacturing process may be complicated. However, in the present invention, since the pressing member 61 is provided on the cover 40 side, the degree of freedom in circuit design can be ensured without increasing the size of the control circuit board 11. Furthermore, the pressing member 61 can have a simple structure and can be attached to the lower surface of the cover 40 by a simple operation.

  The pressing member 61 is formed of a sheet-like rubber material. According to such a configuration, since the pressing member 61 is elastic, the pressing force by the pressing member 61 is adjusted so as not to be an excessive pressing force. Therefore, it is possible to prevent damage such as cracking in the soldering portion 15 due to the pressing force of the pressing member 61. Further, since the contact with the electronic component 13 is soft, it is possible to prevent the pressing member 61 and the electronic component 13 from rubbing and scratching the surface of the electronic component 13.

  Furthermore, the upper surface of the electronic component 13 is planarly held by the pressing member 61 formed in a sheet shape. Here, when a part of the upper surface of the electronic component 13 is pressed, the pressing force acting on the electronic component 13 is biased, and the pressing force is concentrated on a part of the soldering portion 15 to cause damage. There is a risk that. However, according to the present invention, since the upper surface of the electronic component 13 is pressed evenly, such a situation can be avoided.

  In addition, since the pressing member 61 is formed of a heat conductive rubber material, the heat dissipated from the electronic component 13 is immediately transmitted to the cover 40 via the pressing member 61 and quickly radiated to the outside.

  As described above, according to the present embodiment, since the pressing member 61 for preventing the vibration of the electronic component 13 is provided on the case 20 side, the pressing member 61 can have a simple structure and a control circuit. The degree of freedom in circuit design can be ensured without increasing the size of the substrate 11.

  Since the pressing member 61 is a sheet-like rubber material attached to the lower surface of the cover 40, the pressing member 61 is adjusted so that the pressing force generated on the electronic component 13 does not become excessive pressing force. It is possible to prevent the occurrence of damage such as cracks in the soldering portion 15 between the electronic component 13 and the substrates 11 and 12 due to the pressing force. Moreover, since the upper surface of the electronic component 13 is hold | maintained planarly, the whole upper surface is pressed down equally. Further, since the contact with the electronic component 13 becomes soft, it is possible to avoid scratching the surface of the electronic component 13 due to the pressing member 61 and the electronic component 13 rubbing against each other.

  Further, by forming the pressing member 61 from a thermally conductive material, heat generated from the electronic component 13 is quickly transmitted through the pressing member 61 and dissipated to the outside, so that heat dissipation is improved.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

(1) In this embodiment, the pressing member 61 formed of a heat conductive material is used. In addition to this, for example, a metal such as aluminum having a high heat conductivity, or a heat conductive resin is used. A cover may be used. Thereby, the heat transmitted to the cover via the pressing member is radiated to the outside more promptly.
(2) On the other hand, when the temperature outside the lid is high, heat transfer to the inside can be prevented and an increase in internal temperature can be suppressed by using a heat insulating material for the pressing member.

  (3) In the present embodiment, the pressing member 61 is formed of a rubber material, but is not limited thereto, and may be formed of, for example, a sponge material.

External perspective view of electrical junction box in this embodiment The exploded perspective view of the electrical junction box in this embodiment The perspective view which looked at the cover provided with the pressing member from the lower part Side cross-sectional view of the electrical junction box attached to the vehicle panel The partial expanded sectional view showing the state in which the pressing member affixed on the lower surface of the cover contact | abutted on the upper surface of the electronic component

Explanation of symbols

1 ... Electric junction box 11 ... Control circuit board (circuit board)
13 ... electronic component 20 ... case (case part)
40 ... Cover (lid)
61 ... Holding member

Claims (7)

An electrical junction box comprising a circuit board on which electronic components are mounted, and a case portion for housing the circuit board,
The case portion includes a lid portion that covers the circuit board from a surface side on which the electronic component is mounted, and the lid portion is in contact with a surface opposite to the side facing the previous circuit board in the electronic component. An electrical junction box provided with a pressing member for pressing the electronic component. The electrical junction box according to claim 1, wherein the pressing member is an elastic member. The electrical connection box according to claim 2, wherein the elastic member is a cushioning material lined on the inner surface of the lid. The electrical junction box according to any one of claims 1 to 3, wherein the pressing member is made of a heat conductive material. The electrical junction box according to claim 1, wherein the lid is made of a heat conductive material. The electrical junction box according to claim 1, wherein the pressing member is made of a heat insulating material. The electrical junction box according to any one of claims 1 to 3, wherein the lid is made of a heat insulating material.

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