Heat transfer member-equipped substrate, circuit body, and electrical junction box

Abstract

Provided is a heat transfer member-equipped substrate 10 comprising a printed board 13 that has a through hole 15 and a heat transfer member 14 that is attached to the printed board 13, wherein: the heat transfer member 14 has a metal shaft part 14A that is inserted in the through hole 15, a metal head part 14C that is disposed outside the through hole 15, and an insulating heat dissipation adhesive sheet 14B that is disposed between the shaft part 14A and the head part 14C; the head part 14C has a larger outer shape than the through hole 15 when viewed from a direction orthogonal to the board surface of the printed board 13; and the insulating heat dissipation adhesive sheet 14B bonds the shaft part 14A and the head part 14C.

Description

Substrate with heat transfer member, circuit body, and electrical connection box

[0001] The present disclosure relates to a substrate with a heat transfer member, a circuit body, and an electrical junction box.

[0002] Conventionally, a metal member-equipped substrate to which a metal member is attached has been known (see, for example, Patent Document 1). Specifically, the metal member-equipped substrate described in Patent Document 1 includes a printed circuit board having a through hole and a metal member attached to the printed circuit board. The metal member is an integral member having a shaft portion inserted into the through hole and a head portion having a diameter larger than the diameter of the through hole and disposed outside the through hole.

[0003] Patent Document 1 describes a circuit body that includes the metal-member-equipped substrate, an electronic component connected to the end face of the stem opposite to the head, a heat dissipation member overlaid on the metal-member-equipped substrate, and a heat transfer material that is disposed between the head of the metal component and the heat dissipation member and is in close contact with both the head of the metal component and the heat dissipation member. In this circuit body, heat from the electronic component is transferred to the heat dissipation member via the stem, the head, and the heat transfer material, and is then dissipated to the outside by the heat dissipation member.

[0004] Patent No. 6981564

[0005] However, the substrate with metal members described in Patent Document 1 has room for improvement in terms of efficiently dissipating heat generated by electronic components. This specification discloses a technology that can efficiently dissipate heat generated by electronic components while ensuring insulation between the electronic components and heat dissipation members.

[0006] The substrate with heat transfer member of the present disclosure comprises a printed circuit board having a through hole and a heat transfer member attached to the printed circuit board, wherein the heat transfer member has a metal shaft inserted into the through hole, a metal head arranged outside the through hole, and an insulating, heat-dissipating adhesive sheet arranged between the shaft and the head, wherein the head has an outer shape larger than the through hole when viewed in a direction perpendicular to the surface of the printed circuit board, and the insulating, heat-dissipating adhesive sheet bonds the shaft and the head.

[0007] According to the above configuration, heat generated by the electronic component can be efficiently dissipated while ensuring insulation between the electronic component and the heat dissipation member.

[0008] FIG. 1 is a cross-sectional view of an electrical junction box according to the first embodiment. FIG. 2 is a cross-sectional view of a circuit body according to the first embodiment. FIG. 3 is a top view of a printed circuit board according to the first embodiment. FIG. 4 is an exploded perspective view of a heat transfer member according to the first embodiment. FIG. 5 is a top view of a printed circuit board and a heat dissipation member according to the first embodiment. FIG. 6 is a top view of a printed circuit board according to the second embodiment. FIG. 7 is a top view of three heat transfer members according to the second embodiment. FIG. 8 is a cross-sectional view of a circuit body according to the second embodiment. FIG. 9 is a cross-sectional view of a circuit body according to the third embodiment. FIG. 10 is a cross-sectional view of a circuit body according to the fourth embodiment. FIG. 11 is a cross-sectional view of a circuit body according to the fifth embodiment.

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0010] (1) A substrate with a heat transfer member of the present disclosure comprises a printed circuit board having a through hole and a heat transfer member attached to the printed circuit board, wherein the heat transfer member has a metal shaft inserted into the through hole, a metal head disposed outside the through hole, and an insulating heat dissipation adhesive sheet disposed between the shaft and the head, wherein the head has an outer shape larger than the through hole when viewed in a direction perpendicular to the surface of the printed circuit board, and the insulating heat dissipation adhesive sheet bonds the shaft and the head.

[0011] The metal member described in the aforementioned Patent Document 1 has an integrated shaft and head, and silicone grease is disposed between the head and the heat dissipation member as a heat transfer material. Although silicone grease has a higher thermal conductivity than general adhesives, a certain thickness is required to ensure insulation, and there is room for improvement in terms of efficiently transferring heat from the metal member to the heat dissipation member.

[0012] According to the substrate with heat transfer member described in (1) above, the heat transfer member is divided into a stem portion and a head portion, and an insulating, heat-dissipating adhesive sheet is disposed between them, ensuring insulation between the stem portion and the head portion by the insulating, heat-dissipating adhesive sheet. Therefore, the heat transfer material is not required to be insulating, and a heat transfer material with high heat conductivity can be selected regardless of whether it is insulating or not. Therefore, heat transferred from the electronic component to the head portion via the stem portion and the insulating, heat-dissipating adhesive sheet can be efficiently transferred to the heat dissipation member. In other words, heat generated by the electronic component can be efficiently dissipated while ensuring insulation between the electronic component and the heat dissipation member.

[0013] Alternatively, according to the substrate with heat transfer member described in (1) above, since the insulating heat-dissipating adhesive sheet ensures insulation between the stem and the head, there is no need to ensure insulation between the heat transfer member and the heat dissipating member. Therefore, the head and the heat dissipating member can be integrated. Integrating the head and the heat dissipating member eliminates the need for a heat transfer material, so heat transferred from the electronic component to the head via the stem and the insulating heat-dissipating adhesive sheet can be efficiently transferred to the heat dissipating member (here, the heat dissipating member integrated with the head). In other words, heat generated by the electronic component can be efficiently dissipated while ensuring insulation between the electronic component and the heat dissipating member. Integrating the head and the heat dissipating member also eliminates the need for a heat transfer material, which has the effect of reducing the number of components.

[0014] (2) In the substrate with heat transfer member described in (1) above, the insulating heat dissipation adhesive sheet is arranged outside the through hole and has an outer shape larger than the through hole when viewed from a direction perpendicular to the plate surface of the printed circuit board, and the part of the surface of the insulating heat dissipation adhesive sheet to which the shaft portion is adhered, but to which the shaft portion is not adhered, may be adhered to the printed circuit board.

[0015] According to the substrate with a heat transfer member described above in (2), the heat transfer member can be fixed to the printed circuit board by the insulating and heat-dissipating adhesive sheet. That is, the insulating and heat-dissipating adhesive sheet also serves to fix the heat transfer member to the printed circuit board.

[0016] (3) The substrate with a heat transfer member according to (1) or (2) above may include a plurality of the heat transfer members, and the heads of the plurality of heat transfer members may be connected to each other.

[0017] Conventionally, a certain amount of space has been maintained between the heads of multiple metal members to ensure insulation between the metal members. According to the substrate with heat transfer member described above in (3), the shaft and the heads are insulated by the insulating heat-dissipating adhesive sheet, so there is no need to ensure insulation between the heads. This makes it possible to configure the heads of multiple heat transfer members from a single member. Configuring the heads of multiple heat transfer members from a single member reduces the number of parts, thereby reducing the manufacturing cost of multiple heat transfer members. According to the substrate with heat transfer member described above in (3), there is no need to maintain space between the heads, so a single large head can be used. Increasing the head size increases the contact area between the head and the heat transfer material, which has the advantage of improving heat transfer.

[0018] (4) The circuit body of the present disclosure includes a substrate with a heat transfer member described in any one of (1) to (3) above, an electronic component connected to the end face of the shaft portion opposite the head side, a heat dissipation member arranged on the opposite side of the substrate with heat transfer member from the electronic component, and a heat transfer material arranged between the substrate with heat transfer member and the heat dissipation member and in close contact with the head and the heat dissipation member.

[0019] According to the circuit body described in (4) above, since the insulating and heat-dissipating adhesive sheet ensures insulation, it is possible to select a heat-conducting material with high heat conductivity regardless of whether it has insulating properties or not, thereby enabling efficient dissipation of heat generated by electronic components.

[0020] (5) The circuit body of the present disclosure comprises a substrate with a heat transfer member described in any one of (1) to (3), an electronic component connected to the end face of the shaft portion opposite the head side, and a heat dissipation member arranged on the opposite side of the substrate with a heat transfer member from the electronic component, and the head and the heat dissipation member are integrated.

[0021] According to the circuit body described in (5) above, since the insulating and heat-dissipating adhesive sheet ensures insulation, there is no need to insulate the head and the heat-dissipating member. This makes it possible to integrate the head and the heat-dissipating member. Integrating the head and the heat-dissipating member eliminates the need for a heat-conducting material, reducing the number of parts and the manufacturing cost of the circuit body. Since the head and the heat-dissipating member are integrated, there is also the advantage that heat transfer between the head and the heat-dissipating member is improved compared to when a heat-conducting material is disposed between the head and the heat-dissipating member.

[0022] (6) In the circuit body described in (5) above, the heat dissipation member may have a plurality of heat dissipation fins protruding on the side opposite to the head and the insulating heat dissipation adhesive sheet.

[0023] According to the circuit body described in (6) above, the heat dissipation member has heat dissipation fins, so that the heat generated by the electronic component can be dissipated more efficiently while ensuring insulation between the electronic component and the heat dissipation member.

[0024] (7) In the circuit body described in (4) above, the area of ​​the heat dissipation member may be smaller than the area of ​​the printed circuit board when viewed in a direction perpendicular to the surface of the printed circuit board.

[0025] According to the circuit body described in (7) above, the heat dissipation member can be made smaller and lighter than when the area of ​​the heat dissipation member is the same as or larger than the area of ​​the printed circuit board.

[0026] (8) In the circuit body described in (7) above, the area of ​​the heat dissipation member may be the same as the area of ​​the head portion when viewed in a direction perpendicular to the surface of the printed circuit board.

[0027] According to the circuit body described in (8) above, the heat dissipation member can be made smaller and lighter than when the area of ​​the heat dissipation member is larger than the area of ​​the head.

[0028] (9) An electrical junction box according to the present disclosure includes the circuit body described in (4) above and a case that covers the circuit body.

[0029] According to the electrical connection box described in (9) above, heat generated by the electronic component can be efficiently dissipated while ensuring insulation between the electronic component and the heat dissipation member. [Details of the Embodiments of the Present Disclosure] The following describes embodiments of the present disclosure. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0030] <Embodiment 1> In the following description, the up-down direction and the left-right direction refer to the up-down direction and the left-right direction shown in Fig. 1, and the front-rear direction refers to the front-rear direction shown in Fig. 3. In the following description, the reference numerals in the drawings may be omitted for the same components, with some exceptions.

[0031] An electrical junction box 1 according to a first embodiment will be described with reference to Figure 1. The electrical junction box 1 is an electronic device mounted on a vehicle, and is provided on a power line connecting the vehicle's power source and an electrical load, functioning as a DC-DC converter or inverter. The electrical junction box 1 includes a circuit body 2 and a case 3 that covers the circuit body 2. The case 3 is made of a metal such as aluminum or an aluminum alloy, or a synthetic resin, and is formed in a box shape that is open at the bottom.

[0032] (1) Circuit Body The circuit body 2 includes a substrate 10 with a heat transfer member, an electronic component 11 mounted on the upper surface of the substrate 10 with a heat transfer member, a heat dissipation member 12 disposed below the substrate 10 with a heat transfer member, and a heat transfer material 16 disposed between the substrate 10 with a heat transfer member and the heat dissipation member 12.

[0033] (1-1) Substrate with Heat Conducting Member As shown in FIG. 2, the substrate with heat conducting member 10 includes a printed circuit board 13 and a heat conducting member 14.

[0034] (1-1-1) Printed Circuit Board The printed circuit board 13 is a board on which a circuit pattern is printed. As shown in Figures 2 and 3, the printed circuit board 13 has a circular through-hole 15 formed therein into which the shaft portion 14A of the heat transfer member 14 is inserted. The through-hole 15 penetrates the printed circuit board 13 in the thickness direction. As shown in Figure 1, the through-hole 15 is formed at a position where the electronic component 11 is to be mounted.

[0035] (1-1-2) Heat Transfer Member The heat transfer member 14 will be described with reference to Fig. 4. The heat transfer member 14 is a member for transferring heat from the electronic component 11 to the heat dissipation member 12. The heat transfer member 14 is composed of three members: a shaft portion 14A, an insulating heat dissipation adhesive sheet 14B, and a head portion 14C.

[0036] The shaft portion 14A is made of a metal such as copper, a copper alloy, aluminum, an aluminum alloy, iron, or stainless steel, and is formed in a cylindrical shape. The diameter of the shaft portion 14A is, for example, approximately the same as the diameter of the through-hole 15. The axial length of the shaft portion 14A is, for example, approximately the same as the thickness of the printed circuit board 13. The insulating heat-dissipating adhesive sheet 14B is disposed between the shaft portion 14A and the head portion 14C. The insulating heat-dissipating adhesive sheet 14B is a sheet having thermal conductivity and insulation properties, and is formed in, for example, a disk shape. The insulating heat-dissipating adhesive sheet 14B has, for example, an outer shape larger than the through-hole 15 when viewed in a direction perpendicular to the surface of the printed circuit board 13. For example, the insulating heat-dissipating adhesive sheet 14B has a diameter larger than the through-hole 15 of the printed circuit board 13. An example of the insulating heat-dissipating adhesive sheet 14B is a sheet made of epoxy resin containing a thermally conductive filler such as ceramics, which is formed into an adhesive sheet.

[0037] For example, the head 14C is made of the same material as the shaft 14A and is formed in a disk shape that is slightly larger than the insulating and heat-dissipating adhesive sheet 14B. The head 14C may be made of a different material from the shaft 14A.

[0038] 2, the heat transfer member 14 is configured as a single component by adhering the shaft portion 14A and the head portion 14C to the insulating heat-dissipating adhesive sheet 14B. The shaft portion 14A is inserted into the through-hole 15 of the printed circuit board 13. When the shaft portion 14A is inserted into the through-hole 15 of the printed circuit board 13, the top surface of the shaft portion 14A and the top surface of the printed circuit board 13 are generally flush with each other. The top surfaces of the shaft portion 14A and the top surface of the printed circuit board 13 do not necessarily have to be flush with each other.

[0039] When the shaft portion 14A is inserted into the through-hole 15 of the printed circuit board 13, the head portion 14C is positioned outside the through-hole 15. Furthermore, when the shaft portion 14A is inserted into the through-hole 15 of the printed circuit board 13, the insulating heat-dissipating adhesive sheet 14B is positioned, for example, outside the through-hole 15. The portion of the surface of the insulating heat-dissipating adhesive sheet 14B to which the shaft portion 14A is adhered, but to which the shaft portion 14A is not adhered, is adhered to the underside of the printed circuit board 13. The heat transfer member 14 is attached to the printed circuit board 13 by adhering the insulating heat-dissipating adhesive sheet 14B to the underside of the printed circuit board 13.

[0040] (1-2) Electronic Component As shown in FIG. 1, the electronic component 11 is mounted at a position where the through hole 15 is formed. The electronic component 11 is assumed to be a component that generates a large amount of heat. Examples of the electronic component 11 that generates a large amount of heat include a field effect transistor (FET) and an insulated gate bipolar transistor (IGBT). However, the electronic component 11 that generates a large amount of heat is not limited to these, and may be another electronic component.

[0041] The electronic component 11 is soldered to the upper surface of the shaft portion 14A of the heat transfer member 14, and heat from the electronic component 11 is transferred to the shaft portion 14A via the solder. The electronic component 11 only needs to be in contact with the shaft portion 14A, and does not necessarily have to be soldered to the shaft portion 14A.

[0042] (1-3) Heat Dissipation Member The heat dissipation member 12 will be described with reference to Figure 2. The heat dissipation member 12 is a member for dissipating heat transferred from the electronic component 11 to the heat transfer member 14 to the outside. The heat dissipation member 12 is made of a metal with high thermal conductivity, such as aluminum or an aluminum alloy. The heat dissipation member 12 has a flat substrate portion 12A and a plurality of heat dissipation fins 12B provided on the underside of the substrate portion 12A. The plurality of heat dissipation fins 12B extend downward and parallel to each other.

[0043] As shown in FIG. 5 , the heat dissipation member 12 according to the first embodiment has a rectangular shape that is slightly larger than the heat transfer member-equipped substrate 10 when viewed in a direction perpendicular to the surface of the printed circuit board 13. In this first embodiment, the direction perpendicular to the surface of the printed circuit board 13 corresponds to, for example, the up-down direction. As shown in FIG. 1 , a plurality of spacer portions 12C that protrude upward are integrally formed on the peripheral edge of the upper surface of the heat dissipation member 12. The outer peripheral edge of the heat transfer member-equipped substrate 10 is fixed to the spacer portions 12C with screws. Because the outer peripheral edge of the printed circuit board 13 is supported by the spacer portions 12C, a predetermined distance (the total thickness of the insulating heat dissipation adhesive sheet 14B, the head portion 14C, and the heat transfer material 16) is maintained between the lower surface of the printed circuit board 13 and the upper surface of the heat dissipation member 12.

[0044] (1-4) Heat Transfer Material The heat transfer material 16 is a member for transferring heat from the heat transfer member 14 to the heat dissipation member 12. The heat transfer material 16 according to the first embodiment is a thermally conductive grease, a thermally conductive adhesive, or the like. The heat transfer material 16 may also be a sheet-like material having thermal conductivity.

[0045] The heat transfer material 16 may be silicone grease. In the first embodiment, the insulating and heat-dissipating adhesive sheet 14B ensures insulation, so the silicone grease does not need to have high insulating properties. Therefore, high heat transfer can be ensured by making the silicone grease thin.

[0046] (2) Effects of the Embodiment In the heat transfer member-equipped substrate 10 according to the first embodiment, the heat transfer member 14 is divided into the stem 14A and the head 14C, and the insulating heat-dissipating adhesive sheet 14B is disposed between them. This ensures insulation between the stem 14A and the head 14C by the insulating heat-dissipating adhesive sheet 14B. Therefore, the heat transfer material 16 is not required to be insulating, and a heat transfer material 16 with high heat conductivity can be selected regardless of whether it is insulating or not. This allows heat transferred from the electronic component 11 to the head 14C via the stem 14A and the insulating heat-dissipating adhesive sheet 14B to be efficiently transferred to the heat dissipation member 12. In other words, heat generated in the electronic component 11 can be efficiently dissipated while ensuring insulation between the electronic component 11 and the heat dissipation member 12.

[0047] Furthermore, with the substrate 10 with heat transfer member, the insulating heat-dissipating adhesive sheet 14B is installed, eliminating the need to consider variations in the thickness of the spacer portion 12C, allowing the heat transfer material 16 to be thinner, improving heat dissipation performance. Specifically, when using conventional insulating heat-dissipating grease between the heat transfer member 14 and the heat dissipating member 12, insulation performance is specified for each thickness (e.g., dielectric strength x [kV / mm]). Because insulating heat-dissipating grease becomes thinner as pressure is applied, a structure is required to ensure a thicker grease thickness, taking into account the structural tolerance of the spacer portion 12C, so that it does not collapse beyond a target value when pressure is applied. On the other hand, if the insulating heat-dissipating adhesive sheet 14B ensures insulation within the heat transfer member 14, there is no need to ensure insulation for the heat transfer material 16 between the heat dissipating member 12 and the heat dissipating member 12, and therefore there is no need to consider the structural tolerance of the spacer portion 12C.

[0048] In the substrate 10 with heat transfer member, the heat transfer member 14 can be fixed to the printed circuit board 13 by the insulating heat dissipating adhesive sheet 14B. That is, the insulating heat dissipating adhesive sheet 14B also serves to fix the heat transfer member 14 to the printed circuit board 13.

[0049] In the circuit body 2 according to the first embodiment, the insulating and heat-dissipating adhesive sheet 14B ensures insulation, so that a heat transfer material 16 having high heat conductivity can be selected regardless of whether it has insulation or not. This allows the heat generated in the electronic component 11 to be efficiently dissipated.

[0050] According to the electrical junction box 1 of the first embodiment, the heat generated by the electronic component 11 can be efficiently dissipated while ensuring insulation between the electronic component 11 and the heat dissipation member 12 .

[0051] Second Embodiment A substrate 210 with a heat transfer member according to a second embodiment will be described with reference to Fig. 6. The substrate 210 with a heat transfer member has three through holes 15 formed therein.

[0052] As shown in Fig. 7, in the second embodiment, a single large head portion 214C is shared by a plurality of (here, three) heat transfer members 214. For convenience, the head portion of each heat transfer member 214 is referred to as a head portion 214D. The head portion 214D of each heat transfer member 214 is rectangular, and three head portions 214D are connected in an L-shape to form a single large head portion 214C. As shown in Fig. 8, in the second embodiment, heat from the electronic component 11 is transferred from the shaft portion 14A to the common head portion 214C via the insulating and heat-dissipating adhesive sheet 14B.

[0053] In the heat transfer member-equipped substrate 210 according to the second embodiment, the shaft portion 14A and the head portion 214C are insulated by the insulating heat dissipation adhesive sheet 14B, so there is no need to ensure insulation between the head portions 214D of the individual heat transfer members 214. This makes it possible to connect the head portions 214D of multiple heat transfer members 14 and configure them as a single member. Configuring the head portions 214D of multiple heat transfer members 14 as a single member reduces the number of parts, thereby reducing the manufacturing cost of multiple heat transfer members 14.

[0054] The substrate 210 with heat transfer members can use one large head 214C because it is not necessary to secure a gap between the heads 214D of the individual heat transfer members 214. Increasing the head 214C increases the contact area between the head 214C and the heat transfer material 16, which has the advantage of improving heat transfer.

[0055] <Embodiment 3> A circuit body 302 according to embodiment 3 will be described with reference to Figure 9. In the above-described embodiment 1, the area of ​​the heat dissipation member 12 is slightly larger than the area of ​​the heat transfer member-equipped substrate 10. In contrast, in the circuit body 302 according to embodiment 3, the area of ​​the heat dissipation member 312 is smaller than the area of ​​the heat transfer member-equipped substrate 10. Specifically, the shape of the heat dissipation member 312 is approximately the same as the shape of the head portion 14C when viewed from above. Therefore, the area of ​​the heat dissipation member 312 and the area of ​​the head portion 14C are approximately the same.

[0056] The circuit body 302 according to the third embodiment includes a plate-shaped resin member 303. A through hole 304 is formed in the resin member 303, penetrating the plate in the thickness direction. A heat dissipation member 312 is inserted into the through hole 304 and supported by the resin member 303. The heat dissipation member 312 is exposed to the outside of the electrical junction box 1 through the through hole 304.

[0057] According to the circuit body 302 of the third embodiment, the heat dissipation member 312 can be made smaller and lighter than when the area of ​​the heat dissipation member 312 is larger than the area of ​​the head portion 14C.

[0058] According to the circuit body 302, the area of ​​the heat dissipation member 312 when viewed from above is approximately the same as the area of ​​the head 14C, so the heat dissipation member 312 can be made smaller and lighter than when the area of ​​the heat dissipation member 312 is larger than the area of ​​the head 14C.

[0059] 10 , a circuit body 402 according to a fourth embodiment will be described. In the fourth embodiment, the head portion 14C is integrated with a heat dissipation member 412. The heat dissipation member 412 integrated with the head portion 14C is exposed to the outside of the electrical junction box 1 through the through-hole 304.

[0060] In the circuit body 202 according to the fourth embodiment, the insulating heat-dissipating adhesive sheet 14B ensures insulation between the shank 14A and the head 14C, eliminating the need for insulation between the heat transfer member 14 and the heat dissipating member 412. This allows the head 14C and the heat dissipating member 412 to be integrated. Integrating the head 14C and the heat dissipating member 412 eliminates the need for the heat transfer material 16, allowing heat transferred from the electronic component 11 to the head 14C via the shank 14A and the insulating heat-dissipating adhesive sheet 14B to be efficiently transferred to the heat dissipating member 412 (here, the heat dissipating member 412 integrated with the head 14C). In other words, heat generated by the electronic component 11 can be efficiently dissipated while ensuring insulation between the electronic component 11 and the heat dissipating member 412. Integrating the head 14C and the heat dissipating member 412 also eliminates the need for the heat transfer material, resulting in a reduction in the number of components.

[0061] <Embodiment 5> Embodiment 5 will be described with reference to Figure 11. Embodiment 5 is a modification of embodiment 4. In a circuit body 502 according to embodiment 5, a plurality of heat dissipation fins 413 are integrally formed on a heat dissipation member 412. The plurality of heat dissipation fins 413 protrude from the side opposite to the head portion 14C and the insulating heat dissipation adhesive sheet 14B. In other respects, embodiment 5 is substantially the same as embodiment 4.

[0062] According to the circuit body 502 of embodiment 5, the heat dissipation member 412 has heat dissipation fins 413, so that the heat generated by the electronic component 11 can be dissipated more efficiently while ensuring insulation between the electronic component 11 and the heat dissipation member 412.

[0063] <Other Embodiments> (1) In the above-described first embodiment, the heat transfer member 14 is attached to the printed circuit board 13 by adhering the insulating and heat-dissipating adhesive sheet 14B to the underside of the printed circuit board 13. However, the heat transfer member 14 may be attached to the printed circuit board 13 by filling the space between the shaft portion 14A and the through-hole 15 with solder. Alternatively, the shaft portion 14A may be fixed in the through-hole 15 by press-fitting, or may be fixed with an adhesive.

[0064] (2) In the above embodiment, the electrical junction box functions as a DC-DC converter or an inverter, but the function of the electrical junction box is not limited to this. The function of the electrical junction box can be determined as appropriate.

[0065] (3) In the above embodiment, the electrical junction box is mounted on a vehicle. However, the electrical junction box is not limited to being mounted on a vehicle.

[0066] (4) In the above embodiment, the insulating heat-dissipating adhesive sheet 14B has a diameter larger than that of the through-hole 15, but the insulating heat-dissipating adhesive sheet 14B may have the same diameter as the through-hole 15 or a diameter smaller than that of the through-hole 15. When the insulating heat-dissipating adhesive sheet 14B has a diameter smaller than that of the through-hole 15, the insulating heat-dissipating adhesive sheet 14B may extend into the through-hole 15.

[0067] (5) In the above embodiment, the head 14C is illustrated as being slightly larger than the insulating heat-dissipating adhesive sheet 14B, but the head 14C may have the same diameter as the insulating heat-dissipating adhesive sheet 14B, or may have a smaller diameter than the insulating heat-dissipating adhesive sheet 14B.

[0068] (6) In the above embodiment, the shaft portion 14A, the insulating and heat-dissipating adhesive sheet 14B, and the head portion 14C are circular when viewed from above, but they do not have to be circular. For example, they may be polygonal when viewed from above, or any other shape other than a polygon.

[0069] 1: Electrical junction box 2: Circuit body 3: Case 10: Board with heat transfer member 11: Electronic component 12: Heat dissipation member 12A: Board portion 12B: Heat dissipation fin 12C: Spacer portion 13: Printed circuit board 14: Heat transfer member 14A: Shaft portion 14B: Insulating heat dissipation adhesive sheet 14C: Head portion 15: Through hole 16: Heat transfer material 202: Circuit body 210: Board with heat transfer member 214: Heat transfer member 214C: Head portion 214D: Head portion 302: Circuit body 303: Resin member 304: Through hole 312: Heat dissipation member 402: Circuit body 412: Heat dissipation member 413: Heat dissipation fin 502: Circuit body

Claims

1. A board with a heat transfer member, comprising: a printed circuit board having a through hole; and a heat transfer member attached to the printed circuit board, wherein the heat transfer member has a metallic shaft portion inserted into the through hole, a metallic head portion arranged outside the through hole, and an insulating, heat dissipating adhesive sheet arranged between the shaft portion and the head, wherein the head has an outer shape larger than the through hole when viewed in a direction perpendicular to the surface of the printed circuit board, and the insulating, heat dissipating adhesive sheet bonds the shaft portion and the head.

2. A substrate with a heat transfer member as described in claim 1, wherein the insulating heat dissipation adhesive sheet is arranged outside the through hole and has an outer shape larger than the through hole when viewed in a direction perpendicular to the plate surface of the printed circuit board, and a portion of the surface of the insulating heat dissipation adhesive sheet to which the shaft portion is adhered, but not to which the shaft portion is adhered, is adhered to the printed circuit board.

3. A substrate with a heat transfer member according to claim 1 or 2, comprising a plurality of the heat transfer members, the heads of the plurality of heat transfer members being connected to one another.

4. A circuit body comprising: a substrate with a heat transfer member as described in claim 1 or claim 2; an electronic component connected to the end face of the shaft portion opposite the head side; a heat dissipation member arranged on the opposite side of the substrate with heat transfer member from the electronic component; and a heat transfer material arranged between the substrate with heat transfer member and the heat dissipation member and in close contact with the head and the heat dissipation member.

5. A circuit body comprising: a substrate with a heat transfer material as described in claim 1 or claim 2; an electronic component connected to the end face of the shaft portion opposite the head side; and a heat dissipation member arranged on the opposite side of the substrate with a heat transfer material from the electronic component, wherein the head and the heat dissipation member are integrated.

6. A circuit body according to claim 5, wherein said heat dissipating member has a plurality of heat dissipating fins protruding on the side opposite said head and said insulating heat dissipating adhesive sheet.

7. A circuit body according to claim 4, wherein the area of ​​the heat dissipation member is smaller than the area of ​​the printed circuit board when viewed in a direction perpendicular to the surface of the printed circuit board.

8. A circuit body according to claim 7, wherein the area of ​​the heat dissipation member is the same as the area of ​​the head when viewed in a direction perpendicular to the surface of the printed circuit board.

9. An electric connection box comprising: the circuit body according to claim 4; and a case covering the circuit body.

Images