JP2018117473A - Circuit structure manufacturing method, circuit structure, and electric connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a step at a portion at which plural terminals of an electronic component are connected to an insulation substrate and a bus bar.SOLUTION: A method for manufacturing a circuit structure 20 comprising an electronic component 28 having a first terminal 30A and a second terminal 30B, an insulation substrate 21 on the insulation plate of which a conductive path is formed and that has a component mounting face 21A connected to the first terminal 30A, a first bus bar 24 overlaid on the insulation substrate 21, a second bus bar 26 whose thickness dimension is formed larger than that of the first bus bar 24, and that has a component mounting face 26A connected to the second terminal 30B, and a heat radiation member 35 adhered to the first bus bar 24 and the second bus bar 26 by an insulative adhesive 32 includes: an aligning step of aligning the first bus bar 24, the second bus bar 26 and a die 40 so that height of the component mounting face 21A of the insulation substrate 21 becomes equal to that of the component mounting face 26A of the second bus bar 26; and an adhesion step of making the first bus bar 24 and the second bus bar 26 adhere to the heat radiation member 35 by the insulative adhesive 32 after the aligning step.SELECTED DRAWING: Figure 3

Description

  In this specification, the technique regarding a circuit structure and an electrical junction box is disclosed.

  2. Description of the Related Art Conventionally, there has been known a circuit configuration body that is disposed between a power source of a vehicle and a load such as a lamp, a horn, and a motor and performs energization and power interruption. The circuit structure of Patent Document 1 includes a control circuit board on which a conductor pattern is formed by a printed wiring technique, and a bus bar bonded to the back surface of the control circuit board. The bus bar is exposed from the opening of the control circuit board. The electronic component mounted on the surface side of the control circuit board is electrically connected to both the conductor pattern on the surface of the control circuit board and the bus bar exposed from the opening by soldering or the like.

JP 2003-164039 A

  By the way, according to said structure, a level | step difference arises according to the thickness dimension of a control circuit board and an adhesive agent between the conductor pattern of the surface of a control circuit board, and the bus bar exposed from the opening part of a circuit board. Yes. Therefore, in order to connect the electronic component to both the conductor pattern and the bus bar, for example, according to the step, an operation of bending the lead terminal of the electronic component or a relay member having a thickness dimension corresponding to the step There is a problem that manufacturing costs increase due to an increase in work processes and an increase in the number of parts.

  The technology described in the present specification has been completed based on the above-described circumstances, and suppresses the occurrence of a step at a location where a plurality of terminals of an electronic component are connected to an insulating substrate and a bus bar. With the goal.

  A method of manufacturing a circuit structure described in this specification includes an electronic component having a first terminal and a second terminal, and a component mounting surface in which a conductive path is formed in an insulating plate and connected to the first terminal. An insulating substrate having a first bus bar overlaid on the insulating substrate, a second bus bar having a component mounting surface connected to the second terminal and having a thickness dimension larger than that of the first bus bar; And a heat dissipating member bonded to the second bus bar with an insulating adhesive, wherein the component mounting surface of the insulating substrate and the height of the component mounting surface of the second bus bar are high. An alignment step of arranging the first bus bar and the second bus bar on the alignment member so as to equalize, and after the alignment step, the first bus bar and the second bus bar are bonded to the heat dissipation member with the adhesive Gluer And, it performs.

  The circuit structure described in this specification includes an electronic component having a first terminal and a second terminal, an insulating substrate having a component mounting surface in which a conductive path is formed in an insulating plate and connected to the first terminal. A first bus bar overlaid on the insulating substrate, a second bus bar having a component mounting surface formed to have a thickness dimension larger than that of the first bus bar and connected to the second terminal, the first bus bar, And a heat dissipating member bonded to the second bus bar with an insulating adhesive, wherein the component mounting surface of the insulating substrate and the component mounting surface of the second bus bar are made equal in height. The adhesive has advanced into a gap between the first bus bar and the second bus bar adjacent to each other.

  According to the above configuration, the height of the component mounting surface of the insulating substrate and the component mounting surface of the second bus bar can be made equal in a state where the first bus bar and the second bus bar are bonded to the heat dissipation member with an adhesive. Therefore, it is possible to suppress the occurrence of a step at a location where the plurality of terminals of the electronic component are connected to the insulating substrate and the bus bar. Moreover, it becomes possible to absorb the error of the thickness dimension with the adhesive in the state where the first bus bar is overlapped on the insulating substrate and the second bus bar.

The following embodiments are preferable as the embodiments of the technology described in this specification.
In the bonding step, the first bus bar, the second bus bar, and the heat dissipation member are bonded so that the adhesive advances into a gap between the first bus bar and the second bus bar adjacent to each other.
If it does in this way, the adhesive agent between a 1st bus bar and a 2nd bus bar, and a thermal radiation member can be made into an appropriate thickness dimension. Further, the insulating property between the first bus bar and the second bus bar can be ensured by the adhesive.

  The electrical connection box includes the circuit structure and a cover that covers the circuit structure.

  According to the technique described in the present specification, it is possible to suppress the occurrence of a step at a location where a plurality of terminals of an electronic component are connected to an insulating substrate and a bus bar.

Sectional drawing which shows the electrical-connection box of Embodiment 1. Exploded view of the circuit structure The figure explaining the manufacturing process of a circuit structure The figure explaining the manufacturing process of the circuit structure of Embodiment 2.

<Embodiment 1>
The first embodiment will be described with reference to FIGS.
The electrical junction box 10 is disposed in a power supply path between a power source such as a vehicle battery and a load such as a lamp, a wiper, and a motor, and can be used for a DC-DC converter, an inverter, and the like, for example.

(Electric junction box 10)
As shown in FIG. 1, the electrical junction box 10 includes a circuit structure 20 and a cover 11 that covers the upper side of the circuit structure 20. The cover 11 is made of, for example, a synthetic resin or a metal, and has a box shape with an opening on the lower side.

(Circuit structure 20)
As shown in FIGS. 1 and 2, the circuit structure 20 has an insulating substrate 21, a first bus bar 24 superimposed on the insulating substrate 21, and a thickness dimension (dimension in the vertical direction in FIG. 1) than the first bus bar 24. The second bus bar 26 having a large size, the electronic component 28 mounted on the insulating substrate 21 and the second bus bar 26, and the heat radiating member 35 superimposed on the first bus bar 24 and the second bus bar 26 are provided.

(Insulating substrate 21)
The insulating substrate 21 has a conductive path (not shown) made of copper foil or the like formed on an insulating plate made of an insulating material by a printed wiring technique. The upper surface of the insulating substrate 21 is a component mounting surface 21A on which the electronic component 28 is mounted, and the lower surface of the insulating substrate 21 is a bus bar bonding surface 21B to which the first bus bar 24 is bonded. The conductive path is formed on both upper and lower surfaces of the insulating substrate 21. Note that the conductive path may be formed only on one surface of the insulating substrate 21. Alternatively, a multilayer substrate in which a plurality of conductive paths are formed may be used. An insertion hole 22 through which the second bus bar 26 is inserted is formed through the insulating substrate 21. A plurality of first bus bars 24 are attached to the back surface of the insulating substrate 21 at intervals on the same plane.
The insulating substrate 21 may be provided with a through hole (not shown), and the conductive path of the insulating substrate 21 and the first bus bar 24 may be connected in the through hole by soldering or jumper wires. .

(First bus bar 24)
The first bus bar 24 has a plate shape and is made of a metal such as copper, a copper alloy, aluminum, or an aluminum alloy, and is formed by punching a metal plate material into a shape corresponding to the shape of the conductive path. A second bus bar 26 can be inserted between the adjacent first bus bars 24. The insulating substrate 21 and the first bus bar 24 are bonded together using an adhesive member 23 (for example, an adhesive or an adhesive sheet).

(Second bus bar 26)
The second bus bar 26 has a plate shape made of metal such as copper, copper alloy, aluminum, aluminum alloy, and the upper surface is a component mounting surface 26A on which the electronic component 28 is mounted, and the lower surface is on the heat radiating member 35. The bonding surface 26B is bonded. The component mounting surface 26 </ b> A has a size (area) corresponding to the electronic component 28, and heat of the electronic component 28 is radiated from the heat dissipation member 35 via the second bus bar 26. The thickness dimension of the second bus bar 26 is substantially the same as the thickness dimension of the state (the whole) in which the insulating substrate 21 and the first bus bar 24 are bonded together by the adhesive member 23. The first bus bar 24 and the second bus bar 26 may be formed integrally or separately. When the first bus bar 24 and the second bus bar 26 are separated, for example, the first bus bar 24 and the second bus bar 26 may be directly soldered or connected via a relay component. The second bus bar 26 may be connected to an external power source (not shown), for example.

(Electronic component 28)
The electronic component 28 is composed of, for example, a field effect transistor (FET), a rectangular parallelepiped main body 29, a first terminal 30A connected to the conductive path of the component mounting surface 21A of the insulating substrate 21, and components of the second bus bar 26. And a second terminal 30B connected to the mounting surface 26A. The main body 29 has a rectangular parallelepiped shape and is packaged with a synthetic resin exterior body, the first terminal 30A protrudes from the side surface of the exterior body, and the second terminal 30B is disposed at the lower end of the exterior body. It is exposed from the exterior body. The lower ends of the first terminal 30A and the second terminal 30B have the same height. The first terminal 30A and the second terminal 30B are soldered to the component mounting surfaces 21A and 26A. The electronic component 28 is not limited to a lead terminal protruding in a rod shape, and for example, a so-called leadless component having a short lead terminal length may be used.

(Heat dissipation member 35)
The heat radiating member 35 is made of, for example, a metal material having high thermal conductivity such as aluminum or an aluminum alloy, or a material having thermal conductivity (for example, resin), and the upper surface is a flat adhesive surface 35A, and the lower surface side It has a plurality of heat dissipating fins 36 arranged side by side in a comb blade shape. The heat radiating member 35 is bonded to the first bus bar 24 and the second bus bar 26 with an insulating adhesive 32.

(Adhesive 32)
As the adhesive 32, for example, a room temperature curable adhesive or a heat curable adhesive can be used. For example, an epoxy resin adhesive can be used. When the adhesive 32 is cured, an insulating layer is formed between the first bus bar 24 and the second bus bar 26 and the heat radiating member 35. When the first bus bar 24 and the second bus bar 26 are attached to the heat radiating member 35 via the adhesive 32, the adhesive 32 sandwiched between the first bus bar 24, the second bus bar 26 and the heat radiating member 35 is pressurized. Thus, an insulating wall 33 is formed to enter the gap 31 between the first bus bar 24 and the second bus bar 26 and partition the first bus bar 24 and the second bus bar 26. The upper end of the insulating wall 33 (adhesive 32) is disposed above the upper end of the first bus bar 24, and is disposed, for example, in a substantially intermediate portion in the thickness direction of the insulating substrate 21.

As shown in FIG. 3, the electrical junction box 10 is manufactured using a mold 40 (an example of an “alignment member”).
A plurality of first holding portions 41 that hold the positions of the insulating substrate 21 and the plurality of first bus bars 24 and a second holding portion 42 that holds the positions of the second bus bars 26 are formed on the upper surface of the mold 40. ing. The first holding part 41 is recessed so that the insulating substrate 21 and the plurality of first bus bars 24 can be fitted, and the second holding part 42 is recessed so that the second bus bar 26 can be fitted.
Between the first holding part 41 and the second holding part 42, the convex part 43 that partitions the insulating substrate 21 and the second bus bar 26 includes a bottom face 41 </ b> A of the first holding part 41, and a bottom face 42 </ b> A of the second holding part 42. It protrudes upward from the top. On the outside of the first holding portion 41, a partition wall 44 that is externally fitted to the heat radiating member 35 when the first bus bar 24 and the second bus bar 26 are bonded to the heat radiating member 35 stands. The bottom surface 41A of the first holding part 41 and the bottom surface 42A of the second holding part 42 are formed at substantially the same height (level).

Next, a method for manufacturing the electrical junction box 10 will be described.
(Alignment process)
As shown in FIG. 3, the insulating substrate 21 is fitted into the first holding part 41 of the mold 40 and the second bus bar 26 is fitted into the second holding part 42 of the mold 40. Further, the insulating substrate 21 and the first bus bar 24 are pasted with the adhesive member 23. However, the present invention is not limited to this, and the insulating substrate 21 and the first bus bar 24 are attached to the first holding portion of the mold 40 after the insulating substrate 21 and the first bus bar 24 are attached by the adhesive member 23 (without using the mold 40). 41 may be fitted.

(Adhesion process)
Next, when the adhesive 32 is applied to the first bus bar 24 and the second bus bar 26 or the adhesive surface 35A of the heat radiating member 35 and the heat radiating member 35 is pressed against the first bus bar 24 and the second bus bar 26 side, The adhesive 32 is sandwiched between the bus bar 24 and the second bus bar 26 and the heat radiating member 35, and the adhesive 32 is provided in the gap 31 between the first bus bar 24 and the second bus bar 26 as shown in FIG. Overhangs and fills. For example, when the adhesive 32 is cured by heating or normal temperature, the insulating wall 33 is formed between the first bus bar 24 and the second bus bar 26. Next, the insulating substrate 21, the first bus bar 24 and the second bus bar 26 are removed from the mold 40. At this time, the component mounting surface 21A of the insulating substrate 21 and the component mounting surface 26A of the second bus bar 26 are formed at the same height.

(Component mounting process)
Next, the first terminal 30A and the second terminal 30B of the electronic component 28 are soldered to the component mounting surfaces 21A and 26A of the second bus bar 26 by, for example, reflow soldering. Thereby, the circuit structure 20 is formed.
And the electrical connection box 10 is formed by covering the circuit structure 20 with the cover 11 (FIG. 1).

According to the said embodiment, there exist the following effects | actions and effects.
An electronic component 28 having a first terminal 30A and a second terminal 30B, an insulating substrate 21 having a component mounting surface 21A in which a conductive path is formed in an insulating plate and connected to the first terminal 30A, and an insulating substrate 21 are stacked. The first bus bar 24, the second bus bar 26 having a component mounting surface 26A connected to the second terminal 30B, and the first bus bar 24 and the second bus bar 26. And a heat dissipating member 35 that is bonded with an insulating adhesive 32, and the height of the component mounting surface 21A of the insulating substrate 21 and the component mounting surface 26A of the second bus bar 26 is high. An alignment step of arranging the first bus bar 24 and the second bus bar 26 on the mold 40 (alignment member) so as to be equal, and after the alignment step, the first bus bar 24 and the second bus bar 26 are connected to the heat dissipation member. A bonding step of bonding with the adhesive 32, is carried out in 5.
According to the present embodiment, in a state where the first bus bar 24 and the second bus bar 26 are bonded to the heat radiating member 35 with the adhesive 32, the height of the component mounting surface 21A of the insulating substrate 21 and the component mounting surface 26A of the second bus bar 26 is high. Since it is possible to make the lengths equal, it is possible to suppress the occurrence of steps at locations where the plurality of terminals 30A, 30B of the electronic component 28 are connected to the insulating substrate 21 and the bus bar. In addition, regarding the thickness in the state where the first bus bar 24 is superimposed on the insulating substrate 21 and the thickness of the second bus bar 26, the adhesive 32 can absorb the thickness dimension error even if the thickness dimension error occurs. It becomes possible.

In the bonding process, the first bus bar 24 and the second bus bar 26 and the heat radiating member 35 are bonded so that the adhesive 32 advances into the gap 31 between the first bus bar 24 and the second bus bar 26 adjacent to each other. .
If it does in this way, the adhesive agent 32 between the 1st bus bar 24 and the 2nd bus bar 26, and the thermal radiation member 35 can be made into an appropriate thickness dimension. Further, the insulating property between the first bus bar 24 and the second bus bar 26 can be ensured by the adhesive 32.

<Embodiment 2>
The second embodiment will be described with reference to FIG.
In the second embodiment, the first holding part 51 of the mold 50 holds the position of the first bus bar 24 and does not hold the insulating substrate 21. Since other configurations are the same as those of the first embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

 As shown in FIG. 4, the mold 50 includes a first holding part 51 that has a placement surface 51 </ b> A on which the first bus bar 24 is placed and holds the position of the first bus bar 24, and a second holding part 42. The height of the mounting surface 51A of the first holding part 51 and the bottom face 42A of the second holding part 42 is substantially the same as the thickness dimension of the insulating substrate 21. Between the 1st holding | maintenance part 51 and the 2nd holding | maintenance part 42, the escape recessed part 52 which escapes the adhesive agent 32 in the case of an adhesion | attachment process is formed. On the outer side of the first holding part 51, a partition wall 44 that is fitted on the heat radiating member 35 stands.

A method for manufacturing the electrical junction box 10 will be described.
(Alignment process)
For example, the first bus bar 24 is fitted into the first holding part 51 of the mold 50 and the second bus bar 26 is fitted into the second holding part 42 so that the end of the first bus bar 24 contacts the inner surface of the partition wall 44. Then, the first bus bar 24 and the second bus bar 26 are arranged on the mold 50.

(Adhesion process)
Next, the adhesive 32 is applied to the first bus bar 24 and the second bus bar 26 or the bonding surface 35A of the heat dissipation member 35, and the heat dissipation member 35 is pressed against the first bus bar 24 and the second bus bar 26 side. Then, the adhesive 32 is sandwiched between the first bus bar 24 and the second bus bar 26 and the heat radiating member 35, and the adhesive 32 protrudes and fills the gap 31 between the first bus bar 24 and the second bus bar 26. The For example, when the adhesive 32 is cured by heating or normal temperature, the insulating wall 33 is formed between the first bus bar 24 and the second bus bar 26.
Next, the mold 50 is removed, and the insulating substrate 21 is attached to the first bus bar 24 with the adhesive member 23.

(Component mounting process)
Next, the first terminal 30A and the second terminal 30B of the electronic component 28 are soldered to the component mounting surfaces 21A and 26A of the second bus bar 26 by, for example, reflow soldering. Thereby, the circuit structure 20 is formed. And the electrical connection box 10 is formed by covering the cover 11 from the circuit structure 20 (FIG. 1).

<Other embodiments>
The technology described in the present specification is not limited to the embodiments described with reference to the above description and drawings, and for example, the following embodiments are also included in the technical scope of the present invention.
(1) Although the molds 40 and 50 are used as the alignment members, the present invention is not limited to this, and the first mounting surface 21A of the insulating board 21 and the component mounting surface 26A of the second bus bar 26 are at least equal in height. Any member capable of arranging the bus bar 24 and the second bus bar 26 may be used. For example, the alignment member is not limited to metal, and may be made of synthetic resin.

(2) Although the electronic component 28 is an FET, it is not limited to this. For example, a heat generating component that generates heat in response to energization such as a mechanical relay, a coil, or a capacitor can be used.
(3) Although one electronic component 28 is shown in FIGS. 1 to 4, any number of electronic components 28 can be provided depending on the circuit configuration. A plurality of second bus bars 26 may be provided according to the plurality of electronic components 28.

(4) The adhesive 32 is not limited to the above-described adhesive, and for example, an adhesive sheet in which an adhesive layer is formed on both surfaces of the substrate may be used.
(5) The height of the insulating wall 33 by the adhesive 32 is not limited to the height of the above embodiment. For example, the upper end of the insulating wall 33 may be arranged at a height within the thickness dimension of the first bus bar 24. Further, for example, the adhesive 32 may not be disposed (does not advance) in the gap 31 between the first bus bar 24 and the second bus bar 26, and the insulating wall 33 may not be formed.

(6) The shape of the heat dissipation member 35 is not limited to the shape of the above embodiment. For example, it is good also as not having the radiation fin 36 but flat form.

10: Electrical connection box 11: Cover 20: Circuit structure 21: Insulating substrates 21A, 26A: Component mounting surface 22: Insertion hole 24: First bus bar 26: Second bus bar 28: Electronic component 30A: First terminal 30B: First 2 terminals 31: gap 32: adhesive 33: insulating wall 35: heat dissipation member 40, 50: mold (alignment member)
41, 51: first holding part 42: second holding part

Claims (4)

An electronic component having a first terminal and a second terminal; an insulating substrate having a component mounting surface connected to the first terminal; and a first bus bar overlaid on the insulating substrate. The second bus bar is formed to have a thickness dimension larger than that of the first bus bar and has a component mounting surface connected to the second terminal, and is bonded to the first bus bar and the second bus bar with an insulating adhesive. A heat dissipation member, and a manufacturing method of a circuit structure comprising:
An alignment step of arranging the first bus bar and the second bus bar on an alignment member such that the component mounting surface of the insulating substrate and the component mounting surface of the second bus bar are equal in height;
A method of manufacturing a circuit structure, wherein after the alignment step, the first bus bar and the second bus bar are bonded to the heat radiating member with the adhesive. The said 1st bus-bar, the said 2nd bus-bar, and the said heat radiating member are adhere | attached so that the said adhesive agent may advance to the clearance gap between the said 1st bus-bar and the said 2nd bus-bar adjacent to each other. 2. A method for producing a circuit structure according to 1. An electronic component having a first terminal and a second terminal; an insulating substrate having a component mounting surface connected to the first terminal; and a first bus bar overlaid on the insulating substrate. The second bus bar is formed to have a thickness dimension larger than that of the first bus bar and has a component mounting surface connected to the second terminal, and is bonded to the first bus bar and the second bus bar with an insulating adhesive. A heat dissipating member, and a circuit structure comprising:
The component mounting surface of the insulating substrate and the component mounting surface of the second bus bar are equal in height,
The circuit structure in which the adhesive has advanced into a gap between the first bus bar and the second bus bar adjacent to each other. A circuit structure according to claim 3;
An electrical junction box comprising a cover that covers the circuit structure.

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