JP2004247561A - Circuit structure and method of inspecting the asme - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform the inspection for securing cooling and insulation of a power circuit while thinning and protecting the power circuit in a circuit configuration. <P>SOLUTION: The power circuit 1 is obtained by piling a plurality of bus bars 10 on a circuit board 13 and arranged on a nearly flat surface. This is stuck onto the circuit arranging surface 2a of a radiation member 2 via an insulation layer 5 and protected by the case main body 30. A contactor insertion hole 33h is bored at the case main body 30, and a contactor insertion hole 13h is bored at the circuit board 13. Then, a contactor for positional measurement 60 is inserted respectively to the contactor insertion holes 33h and 13h to measure the height position of the circuit arranging surface 2a and the height position of the top surface of the bus bar 10 to judge whether the contacting state of the bus bar 10 to the circuit arranging surface 2a is good or not based on the difference between the measured height positions. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit structure used as a vehicle power distributor for distributing power from a common vehicle-mounted power supply to a plurality of electronic units, and a method of inspecting the circuit structure.
[0002]
[Prior art]
Conventionally, as a means for distributing power from a common on-board power supply to each electronic unit, an electric connection box in which a power circuit portion is configured by laminating a plurality of bus bar boards and a fuse or a relay switch is incorporated therein is known. ing.
[0003]
In recent years, a switching element such as an FET has been interposed between an input terminal and an output terminal in order to reduce the size of an electric junction box for distributing power from a common vehicle-mounted power supply to each electronic unit and realize high-speed switching control. The development of circuit components is underway. In such a circuit structure, it is desirable to effectively cool the heat generated from the switching element and the like, and from this viewpoint, the circuit arrangement of a heat radiating member formed of a material having excellent heat conductivity such as aluminum. A device in which a power circuit portion is bonded on a surface via an insulating layer has been proposed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-11-204700
[Problems to be solved by the invention]
In the circuit structure in which the power circuit portion is bonded on the circuit arrangement surface of the heat radiating member as described above, the heat generated from the power circuit portion is efficiently radiated to the outside, and the heat radiating member and the power circuit portion In order to maintain the insulation property, the circuit arrangement surface and the power circuit portion are satisfactorily bonded to each other, and the thickness of an insulating layer (including at least a layer made of an adhesive) interposed therebetween is appropriate. Must be within range. Therefore, such inspection of the bonding state is very important for quality control.
[0006]
On the other hand, as the thinning of the power circuit unit is studied, it is necessary to effectively protect the power circuit unit by a case, and the inspection of the adhesion state is performed while satisfying these requirements. It is a big challenge.
[0007]
The present invention has been made on the background of the above-described conventional technology, and inspects an adhesion state between a heat radiating member for cooling the power circuit unit and the power circuit unit while reducing the thickness and protection of the power circuit unit. It is an object of the present invention to provide a circuit structure and a method for inspecting the same, which makes it easy to perform the above.
[0008]
[Means for Solving the Problems]
As a means for solving the above-described problems, the present invention provides a power circuit unit configured by stacking a plurality of bus bars on a circuit board in a state of being arranged substantially on a plane, and a bus bar of the power circuit unit having an insulating layer. A heat dissipating member having a circuit disposition surface adhered through the heat dissipating member, the circuit disposing portion is attached to the heat dissipating member so as to protect the circuit disposing portion from the outside, and at least a part of the circuit disposing surface in the attached state A case having an opening for exposing to the outside, wherein the case has a contact for position measurement with respect to a surface of a region where the power circuit portion and the insulating layer are not provided on the circuit arrangement surface. A case-side contact insertion hole for contacting the power supply unit is provided, and a contact for position measurement with respect to the bus bar is provided on a portion of the circuit board of the power circuit unit which is exposed to the outside by the opening of the case. In which the substrate side contact insertion holes for effecting touch is provided.
[0009]
According to the present invention, a thin power circuit portion is formed by stacking a plurality of bus bars on a circuit board in a state of being arranged substantially on a plane, and the bus bars of the power circuit portion are interposed via an insulating layer. The heat generated by the power circuit unit is released to the outside through the heat dissipating member by being adhered on the circuit disposition surface of the heat dissipating member. Further, the circuit arrangement portion is protected from the outside by the case mounted on the heat dissipation member.
[0010]
Here, in order to sufficiently obtain the cooling effect of the power circuit portion by the heat radiating member and to secure insulation reliability between the two, the degree of adhesion between the bus bar of the power circuit portion and the circuit mounting surface of the heat radiating member is required. Although the thickness of the insulating layer interposed therebetween is important, since the case and the control circuit board are provided with the contact insertion holes, respectively, the contact for the position measurement is utilized by using these contact insertion holes. By bringing the element into contact with an appropriate portion, the degree of adhesion of the bus bar of the power circuit portion to the circuit arrangement surface and the thickness of the insulating layer can be properly and easily evaluated.
[0011]
Specifically, a step of inserting a contact for position measurement into the case-side contact insertion hole and contacting the circuit mounting surface of the heat radiating member to measure the position of the circuit mounting surface; and Measuring the position of the upper surface of the bus bar by inserting a contact for position measurement into the side contact insertion hole and bringing the contact into contact with the upper surface of the bus bar. Based on the difference between the position of the bus bar and the position of the bus bar, it is possible to determine whether the state of adhesion of the bus bar to the circuit mounting surface is good or bad.
[0012]
That is, the difference between the position of the circuit disposition surface and the upper surface position of the bus bar is determined by the thickness of the insulating layer interposed between the circuit disposition surface and the bus bar and the bus bar when the adhesion state of both is good. Since it should correspond to the sum of the thickness and the thickness, the quality of the adhesion state of the bus bar to the circuit arrangement surface can be easily determined from the difference.
[0013]
Since the adhesion and the thickness of the insulating layer can be easily controlled in this way, it is possible to contribute not only to quality improvement but also to cost reduction by saving quality management labor. .
[0014]
The contact hole may be a single contact hole, but the board-side contact hole is provided at a plurality of locations on the circuit board, and the case-side contact hole is provided at a plurality of locations on the case. Is more preferred. For this circuit structure, the difference between the position of the upper surface of the bus bar measured at each of the board-side contact insertion holes and the position of the bus bar measured at the case-side contact insertion hole closest to the board-side contact insertion hole is calculated. By determining the quality of the bonding state of the bus bar to the circuit disposition surface based on the difference between these obtained and determined, a more appropriate inspection can be performed in consideration of the variation in the bonding state depending on the bonding location.
[0015]
The insulating layer may be formed by, for example, applying and curing an adhesive on the circuit arrangement surface of the heat dissipating member, then reapplying the adhesive thereon, and overlaying the bus bar thereon. Good. According to this configuration, the heat dissipating member and the bus bar can be bonded by the reapplied adhesive while maintaining reliable insulation by the insulating layer formed by the first application and curing. Even in this case, it is possible to properly evaluate the thickness of the entire insulating layer by the inspection method.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a circuit structure and a test method therefor according to the present invention will be described with reference to the drawings. Note that here, a circuit component for distributing power supplied from a common power source mounted on a vehicle or the like to a plurality of electrical loads is shown, but the application of the circuit component according to the present invention is not limited to this. It can be widely applied as a circuit component having a heat radiating member and requiring cooling.
[0017]
FIG. 1 is an exploded perspective view of a circuit structure according to the present embodiment. The circuit structure includes a power circuit section 1 including a plurality of bus bars 10, a heat radiation member 2 in which the power circuit section 1 is disposed via an insulating layer 5, and protects the power circuit section 1 from outside. And the case 3 is mounted on the heat radiating member 2 in a state where the sealing member 4 is sandwiched between the case 3 and the heat radiating member.
[0018]
The power circuit section 1 is formed by stacking and bonding a large number of bus bars 10 on a back surface (a lower surface in the figure) of the control circuit board 13 in a state where the bus bars 10 are arranged substantially on a plane. It is configured.
[0019]
The bus bar 10 includes an input bus bar connected to a power supply and an output bus bar for outputting power to the outside, and a plurality of bus bars interposed between the input bus bar and the output bus bar. A switching element (eg, FET, LSI, thyristor, relay switch, etc.) 12 is mounted.
[0020]
A control circuit for controlling the switching operation of each switching element 12 is incorporated in the control circuit board 13, and each switching element 12 is mounted so as to be connected to both the control circuit and the power circuit. ing. Specifically, a control terminal (gate terminal in the case of an FET) of the switching element 12 is directly mounted on the control circuit board 13, and each switching element 12 is mounted through a mounting through hole provided in the control circuit board 13. (The drain terminal and the source terminal in the case of the FET) are mounted on an appropriate bus bar 10.
[0021]
A portion where each bus bar 10 projects outward from the control circuit board 13 is bent upward to form an external connection terminal 14. These external connection terminals 14 are, for example, an input terminal connected to a common vehicle-mounted power supply, an output terminal connected to an electronic unit, and a signal input terminal to which a control signal for controlling each switching element 12 and the like is input. And so on.
[0022]
The heat radiating member 2 is integrally formed in a substantially rectangular shape in plan view from a material having excellent thermal conductivity such as an aluminum-based metal. The upper surface is formed as a flat circuit mounting surface 2a, and a plurality of radiating fins 20 arranged in the left-right direction project downward from the lower surface. The power circuit section 1 is arranged on the circuit arrangement surface 2a via the insulating layer 5 (two insulating layers 5a and 5b in the illustrated example). The periphery of the insulating layer is in a protruding state.
[0023]
In order to form the insulating layer 5, for example, an adhesive having high insulating and thermal conductivity (epoxy adhesive, silicone adhesive, or the like) may be applied and cured, or the circuit mounting surface 2a You may make it stick an insulating sheet on it. In the present embodiment, the insulating layer 5 is formed by applying an adhesive made of an epoxy resin having excellent insulating properties and thermal conductivity.
[0024]
The heat radiation fins 20 can be omitted as appropriate, or instead of the heat radiation fins 20, heat radiation pins or the like may be used which project from the side opposite to the circuit mounting surface 2 a. Further, a narrow groove or the like may be provided on the surface of the heat radiating fin, the heat radiating pin, or the like, so that the surface area may be increased and the heat radiation efficiency may be improved.
[0025]
The case 3 is made of an insulating material and includes a case body 30 formed in a frame shape so as to surround the power circuit section 1 as shown in FIGS. 1 and 2, and an opening formed in the center of the case body 30. The part 32 is finally closed by the lid 31.
[0026]
As shown in FIGS. 1, 2, and 4, the case body 30 has a wall portion 33 having a lower end surface extending along the peripheral portion of the circuit disposition surface 2a, and extends downward from the peripheral portion of the wall portion 33 to dissipate heat. It has a skirt portion 34 for covering the peripheral side surface of the member 2 and a resin sealing member 4 disposed on the lower end surface of the wall portion 33. The circuit arrangement area of the power circuit portion 1, in other words, the heat radiation member 2 It is made to be able to surround.
[0027]
The wall portion 33 has a shape surrounding the circuit arrangement region of the heat radiating member 2, and as shown in FIG. 4, the first vertical wall portion 33 a and the inside from the leading edge of the first vertical wall portion 33 a. The first vertical wall 33a includes a horizontal wall 33b that extends and a second vertical wall 33c that extends further upward (to the side opposite to the heat radiating member 2) from the leading edge of the horizontal wall 33b. Thus, a sealing material filling groove 35 is formed. That is, the sealing material filling groove 35 is provided so as to surround the circuit arrangement area of the circuit arrangement surface 2a, and is filled with the resin sealing material 4. The cross section of the sealing material filling groove 35 is not particularly limited, but is formed in a substantially U-shaped cross section in the present embodiment.
[0028]
The wall 33 has a peripheral side wall height set at least higher than the leg-like terminals 12 a of the switching element 12 mounted on the power circuit section 1, and preferably higher than the heights of these various electronic components 12. It is formed high. That is, the wall portion 33 is formed so as to surround the power circuit portion 1 including various electronic components (the switching element 12 in the present embodiment). In the present embodiment, the height of the peripheral wall of the wall portion 33 is set higher than that of the switching element 12.
[0029]
The opening 32 is formed so as to open substantially the entire area of the control circuit board 13 in the power circuit section 1 upward, and even after the case body 30 is attached to the heat radiating member 2, the power circuit section is opened through the opening 32. 1 can be pressed from above onto the circuit disposition surface 2a of the heat radiating member 2 so that bonding with an adhesive can be further ensured.
[0030]
A plurality of connector housings 36 are formed integrally with the wall 33. Each of the connector housings 36 has a bottom having a terminal through hole 37 through which the external connection terminal 14 of the power circuit section 1 is inserted, and a plurality of connectors projecting to the side opposite to the circuit mounting surface 2a through the terminal through hole 37. A hood 38 surrounding the external connection terminal 14 is provided, and together with these external connection terminals 14, constitutes an external connection connector that can be connected to an external connector (for example, a connector attached to the end of a cable). In the present embodiment, the bottom of the connector housing 36 is constituted by a horizontal wall 33b.
[0031]
In the connector housing 36 according to this embodiment, as shown in FIGS. 3 and 4, the bottom surface of the connector housing 36 is left with a connector contact surface 36a with which the distal end surface of another connector comes into contact. A recess 39 for resin pool which is immersed below 36a (on the side of the heat radiating member 2) is formed, and a through hole 37 for a terminal is provided in a region where the recess 39 for resin pool is formed. In some connector housings 36, as shown in FIGS. 3 and 4, a resin insertion hole communicating from the resin reservoir recess 39 to the inside of the wall 33, specifically, below the horizontal wall 33b. 40 are provided.
[0032]
The resin reservoir recess 39 is provided for introducing and filling a later-described waterproof resin through the terminal through hole 37, and forms a later-described waterproof layer 6 in the resin reservoir recess 39. This is provided to prevent water from penetrating through the terminal through-hole 37 and effectively prevent short-circuiting of the power circuit section 1. It overflows into the pool recess 39. On the other hand, the resin insertion hole 40 assists and strengthens the introduction of the waterproof resin from the terminal through hole 37, and the waterproof resin is introduced into the resin reservoir recess 39 through the resin insertion hole 40.
[0033]
In the illustrated example, the connector housing 36 is formed so that a portion located at a lower end portion thereof is locally bulged outward in a state where the entire circuit structure is vertically placed, and inside the bulged portion 36b. The horizontal wall portion 33b is provided with a drainage hole 36c that opens on the heat radiation member 2 side and outside the resin sealing material 4. The drain hole 36c is for discharging water collected in the connector housing 36, and the water discharged from the drain hole 36c is used as a drain passage 50 between the heat radiation member 2 and the case body 30. Through to the outside.
[0034]
It should be noted that the second vertical wall portion 33c has a notch 51 for drainage at a lower portion when the circuit component is vertically placed, and the notch 51 for drainage faces a surface of a waterproof layer 6 described later. Or higher than the surface of the waterproof layer 6. On the lower surface of the horizontal wall portion 33b, there is a pressing projection 52 for pressing the bus bar 10 constituting the external connection terminal 14.
[0035]
On the other hand, the skirt portion 34 has a frame shape covering the four peripheral side surfaces of the heat radiation member 2, and a pair of opposing side walls are formed in a jagged shape corresponding to the shape of the heat radiation fin 20. Locking claws 53 are formed at appropriate positions of the skirt portion 34 so as to lock the corresponding portions of the heat radiating member 2 so that the case body 30 and the heat radiating member 2 can be firmly assembled.
[0036]
The lid 31 has a plate shape corresponding to the opening 32 of the case main body 30 and is attached to the case main body 30 by a not-shown locking structure, or is attached to the case main body 30 by bonding, welding, or the like. The lid 31 can be omitted as appropriate, but by attaching it, the protection of the power circuit unit 1 becomes more reliable.
[0037]
The resin sealing material 4 is formed in an annular shape surrounding the circuit arrangement area, and can be fitted tightly into the sealing material filling groove 35. The resin sealing material 4 temporarily prevents the waterproofing resin from leaking out of the case body 30 until the waterproofing resin is hardened when the liquid waterproofing resin described later is injected into the inner region. For example, closed-cell foamed rubber is suitable.
[0038]
Further, as a feature of this circuit structure, as shown in FIGS. 6 and 7A and 7B, the control circuit board 13 is provided at a plurality of positions (three positions in the example of FIG. 6) in the thickness direction. Case-side contact holes 13h, 13i, and 13j are provided to penetrate, and a plurality of (three in the example of FIG. 6) of the case wall portion 33 penetrate the upper wall portion of the case wall portion 33 in the wall thickness direction. Child insertion holes 33h, 33i, 33j are provided.
[0039]
The case-side contact insertion holes 33h, 33i, and 33j are provided at positions where the edge of the circuit disposition surface 2a, that is, the portion where the insulating layer 5 is formed is opened upward. As shown in FIG. 7 (a), by inserting the position measuring contact 60 into the contact insertion holes 33h, 33i, 33j, the tip of the contact 60 is directly connected to the circuit mounting surface 2a (ie, the insulating layer). 5) (without interposing 5).
[0040]
On the other hand, the board-side contact insertion holes 13h, 13i, and 13j are provided on the back side of the control circuit board 13 where the bus bar 10 is provided, and these board-side contact insertion holes 13h, 13i are provided. , 13j, as shown in FIG. 7 (b), the tip of the contact 60 is inserted into the upper surface of the bus bar 10 (i.e., the surface superposed on the back of the control circuit board 13). ).
[0041]
Next, a description will be given of a manufacturing process of this circuit component and a method of inspecting the bonded portion.
[0042]
1) Parts manufacturing process The power circuit section 1, the heat radiating member 2, and the case body 30 are separately manufactured. In the case body 30, the resin sealing material 4 is loaded into the sealing material filling groove 35, and the power circuit section 1 is assembled to the case body 30 by inserting the external connection terminal 14 into the terminal through hole 37. . By assembling the power circuit section 1 to the case main body 30 in advance in this way, the alignment of the external connection terminal 14 with respect to the terminal through-hole 32 can be ensured.
[0043]
2) Adhesion Step With the adhesive for forming the insulating layer 5 applied to the circuit arrangement area of the heat radiating member 2, the case body 30 to which the power circuit section 1 is assembled is attached to the heat radiating member 2. As a result, the bus bar 10 of the power circuit section 1 comes into contact with the adhesive and is joined to the circuit arrangement area on the circuit arrangement surface 2a of the heat radiation member 2.
[0044]
Further, appropriate portions (many portions) of the control circuit board 13 in the power circuit portion 1 are pressed through the openings 32 of the case main body 30, and the (insulating layer 5) between the power circuit portion 1 and the circuit arrangement surface 2a is pressed. Through the adhesive). Specifically, the power circuit unit 1 is pressed through the opening 32 of the case main body 30 at a proper position of the power circuit unit 1, in particular, at the periphery of the power circuit unit 1 and the periphery of the switching element 12, so that the power circuit unit 1 is disposed in the circuit arrangement of the heat radiation member 2. Strongly bonded to the area. In this way, by pressing the power circuit unit 1 and joining it to the heat radiating member 2, the bus bar 10 located on the back surface of the power circuit unit 1 is buried in the adhesive, and the insulation between the bus bars 10 Short circuits can be reliably prevented, and the thermal conductivity between the power circuit section 1 and the heat radiating member 2 can be improved. Thereafter, the adhesive is cured by heating to form a complete insulating layer 5.
[0045]
In this step, the case main body 30 is attached to the heat radiating member 2 by locking the locking claws 53 of the skirt portion 34 to corresponding portions of the heat radiating member 2. It may be mounted by a mechanical fixing member such as a bolt or the like, or may be mounted by bonding or the like, and a known mounting method is adopted. When an adhesive resin is used as a waterproof resin described later, the case body 5 may be temporarily attached to the heat radiating member 2.
[0046]
On the other hand, the insulating layer 5 can be formed by only one application of the adhesive. For example, at the time of the first application, the adhesive is hardened without bonding the power circuit section 1 as shown in FIG. A lower insulating layer 5a as shown in FIG. 3B is formed, and the same type of adhesive or a different type of adhesive is applied thereon, and the power circuit unit 1 is bonded with the adhesive, and then the adhesive is applied. May be cured to form the upper insulating layer 5b. In this case, higher insulation reliability can be obtained by forming the lower insulating layer 5a in advance before bonding. For example, even when, for example, a pinhole is formed during the formation of the insulating layer 5a, the adhesive applied on the pinhole fills the pinhole, so that the insulation between the power circuit unit 1 and the heat radiating member 2 becomes more reliable. Become.
[0047]
The adhesive forming the insulating layer 5 is preferably, for example, an adhesive made of an epoxy resin, but other adhesives can be used as long as the adhesive has good thermal conductivity.
[0048]
Through the above steps, the power circuit section 1 is arranged in the circuit arrangement area on the circuit arrangement surface 2a of the heat dissipation member 2, and the circuit arrangement of the heat dissipation member 2 including the power circuit section 1 by the case body 30. A surrounding wall is formed surrounding the circuit arrangement area on the surface 2a. The surrounding wall functions as a dam for the waterproofing resin used when performing a waterproofing step described later.
[0049]
3) Inspection Step In this step, the adhesion between the circuit arrangement surface 2 and the bus bar 10 after the bonding step and the appropriateness of the thickness of the insulating layer 5 interposed therebetween are inspected.
[0050]
First, as shown in FIG. 7A, the entire circuit structure is placed on the reference plane S with the heat radiating member 2 facing downward, and is inserted into each of the case-side contact insertion holes 33h, 33i, 33j. The pin-shaped position measuring contact 60 is sequentially inserted from above, and its tip is brought into direct contact with the circuit arrangement surface 2a (that is, without interposing the insulating layer 5). From the height position of the position measuring contact 60 at this time, the height position of the circuit arrangement surface 2a at a position where each case side contact hole 33h, 33i, 33j is provided (from the reference surface S). The distance H1 in the height direction is determined and stored.
[0051]
Next, as shown in FIG. 2B, the pin-shaped position measuring contacts 60 are sequentially inserted into the respective board-side contact insertion holes 13h, 13i, and 13j from above, and the tip thereof is connected to the bus bar 10 as shown in FIG. (The surface facing the control circuit board 13). From the height position of the position measuring contact 60 at this time, the height position of the upper surface of the bus bar 10 at the position where the board-side contact insertion holes 13h, 13i, and 13j are provided (the height from the reference surface S). The distance H2 is determined and stored.
[0052]
Thereafter, the height position H2 determined for each of the board-side contact insertion holes 13h, 13i, and 13j, and the case-side contact insertion holes 33h and 33i closest to the board-side contact insertion holes 13h, 13i, and 13j, respectively. , 33j with respect to the height position H1 calculated respectively. This difference (H2-H1) should correspond to the sum of the thickness of the bus bar 10 and the thickness of the insulating layer 5 when the bus bar 10 and the circuit arrangement surface 2 are completely adhered to each other via the insulating layer 5. Therefore, based on the calculated value of the difference, the state of adhesion between the circuit arrangement surface 2a and the bus bar 10 can be easily and appropriately evaluated.
[0053]
In the present invention, the specific numbers of the case-side contact insertion holes and the board-side contact insertion holes are not limited, and these insertion holes are not necessarily the same. However, if information on the height position of the circuit disposition surface and the height position of the upper surface of the bus bar is collected at a plurality of positions as shown in this embodiment, it is possible to evaluate the bonding state more appropriately.
[0054]
After the inspection step, a waterproof treatment may be appropriately performed. In this embodiment, it is effective to fill a predetermined amount of liquid waterproof resin into the space surrounded by the case body 30 and to cure the waterproof resin to form the waterproof layer 6.
[0055]
Specifically, a liquid waterproof resin is injected from the opening 32 of the case main body 30 with the circuit mounting surface 2a facing upward, and various electronic components (switching elements 12) mounted on the power circuit section 1 are injected. ) Is filled to the sealing height. At this time, the waterproof resin overflows into the connector housing 36 through the terminal through hole 37 and the resin insertion hole 40, and reaches a predetermined height in the resin reservoir recess 39.
[0056]
When the waterproof resin is filled, the bus bar component plate 11 and the control circuit board 13 including the base end of the external connection terminal 14 are also immersed in the waterproof resin. On the other hand, since the circuit arrangement area is surrounded by the resin sealing material 4, even the liquid waterproof resin does not leak out of the gap between the heat radiation member 2 and the case body 30.
[0057]
The waterproofing resin only needs to have waterproofness, and the material and the like are not particularly limited. However, by using a liquid resin as in the present embodiment, the waterproofing resin can be applied to every corner of the case body 5. It is possible to completely seal the seal. Further, it is preferable to use a resin having a certain elasticity and shape retention even after curing as the waterproofing resin, since it has little effect on the switching element 12, the solder, and the like. Further, it is preferable to use a silicone resin or the like from the viewpoint of not only excellent heat resistance and cold resistance, but also good electrical insulation. In addition, if an adhesive resin is used as the waterproof resin, the work of applying a primer or the like can be omitted, and the work can be simplified. Furthermore, if a resin having excellent thermal conductivity is adopted as the waterproofing resin, not only heat dissipation by the heat radiating member 2 is promoted, but also heat is radiated from the waterproof layer 6 so that the heat radiating property is further improved. Can be.
[0058]
Then, the filled waterproofing resin is cured by heating to form the waterproofing layer 6. Thus, the waterproof layer 6 seals at least a part of the power circuit portion and seals the terminal through-hole inside the case body. Next, the lid 7 that covers the opening 32 of the case main body 30 is manufactured, and after the waterproof layer 6 is formed, the lid 7 is attached to the case main body 30 while covering the opening 32.
[0059]
Note that the formation of the waterproof layer 6 is not necessarily required, and instead of forming the waterproof layer 6, for example, a combination of a sealing material and a lid 31 may be used to cover the waterproofing process.
[0060]
【The invention's effect】
As described above, according to the present invention, the power circuit portion provided on the circuit disposition surface of the heat radiating member is constituted by a plurality of bus bars stacked on a circuit board in a state of being arranged substantially on a plane. Thereby, the thickness can be reduced, and the circuit mounting portion can be protected from the outside by the case mounted on the heat dissipation member.
[0061]
A step of measuring the position of the circuit mounting surface by inserting a contact for position measurement into the case-side contact insertion hole and bringing the contact into contact with the circuit mounting surface of the heat radiation member; Measuring the position of the upper surface of the bus bar by inserting a contact for position measurement into the insertion hole and bringing the contact into contact with the bus bar to perform a process of measuring the upper position of the bus bar. Based on the difference, it is possible to easily and appropriately determine whether or not the adhesion state of the bus bar to the circuit arrangement surface is high, and this inspection can guarantee high insulation reliability and circuit arrangement portion cooling performance. .
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a circuit structure according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a case main body, a resin sealing material, and a heat radiating member in the same circuit structure when viewed from the heat radiating member side.
FIG. 3 is a partially enlarged view of a case main body in the circuit configuration body.
FIG. 4 is a sectional view taken along line VI-VI of FIG. 3;
FIG. 5 is a perspective view showing the switching element in a state where its leg terminals are sealed with a waterproof resin.
FIG. 6 is a plan view of the circuit structure.
FIGS. 7A and 7B are cross-sectional front views showing an inspection process of the circuit structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power circuit part 2 Heat dissipation member 2a Circuit arrangement surface 3 Case 5 Insulating layer 5a Lower insulating layer 5b Upper insulating layer 10 Bus bar 12 Switching element 13 Control circuit boards 13h, 13i, 13j Board side contact hole 30 Case body 33 Wall portions 33h, 33i, 33j Case side contact hole 60 Contact for position measurement

Claims (5)

A heat radiator having a power circuit portion configured by stacking a plurality of bus bars on a circuit board in a state of being arranged substantially on a plane, and a circuit arrangement surface to which the bus bar of the power circuit portion is bonded via an insulating layer. A member, and a case having an opening mounted on the heat radiating member so as to protect the circuit arrangement portion from the outside, and having at least a part of the circuit arrangement surface exposed to the outside in the attached state. In this case, a case-side contact hole for contacting a contact for position measurement to a surface of a region where the power circuit portion and the insulating layer are not provided in the circuit arrangement surface is provided. And a board-side contact insertion hole for contacting a position measurement contact with the bus bar in a portion of the circuit board of the power circuit portion exposed to the outside by the opening of the case. Circuit component, characterized by being. 2. The circuit structure according to claim 1, wherein the board-side contact insertion holes are provided at a plurality of positions on the circuit board, and the case-side contact insertion holes are provided at a plurality of positions of the case. Circuit structure to be used. 3. The circuit structure according to claim 1, wherein the insulating layer is formed by applying and curing an adhesive on a circuit mounting surface of the heat radiating member, and then re-applying an adhesive on the adhesive. 3. A circuit structure characterized by being formed by stacking. The method for inspecting a circuit component according to any one of claims 1 to 3, wherein a contact for position measurement is inserted into the case-side contact insertion hole, and the circuit arrangement surface of the heat radiation member is provided. Measuring the position of the circuit disposition surface by contacting, and inserting a contact for position measurement into the board-side contact insertion hole to make contact with the upper surface of the bus bar to thereby determine the position of the upper surface of the bus bar. Measuring the position of the circuit arrangement surface and the position of the bus bar based on the measured difference between the position of the circuit arrangement surface and the position of the bus bar. Inspection method. 3. The method for inspecting a circuit component according to claim 2, wherein a contact for position measurement is inserted into each of the case-side contact insertion holes and brought into contact with the circuit mounting surface of the heat radiating member. Measuring the position of the mounting surface, and measuring the position of the upper surface of the bus bar by inserting a contact for position measurement into each of the substrate-side contact insertion holes and contacting the upper surface of the bus bar. The difference between the position of the upper surface of the bus bar measured at each of the board-side contact insertion holes and the position of the bus bar measured at the case-side contact insertion hole closest to the board-side contact insertion hole is determined, and the difference between these is determined. A method for inspecting a state of adhesion of the bus bar to the surface on which the circuit is provided, based on the method.

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