Method for manufacturing an electronic component cooling structure, and electronic component cooling structure

Abstract

The present invention provides a method for manufacturing an electronic component cooling structure and an electronic component cooling structure that can reduce the load on a heat sink while improving heat dissipation and insulation. [Solution] The method for manufacturing an electronic component cooling structure comprises a step S101 of placing a resin sheet 107 on a mounting surface 3a, and a step S102 after step S101 of applying pressure to the resin sheet 107 toward the mounting surface 3a using a pressure jig 180 and heating the resin sheet 107 to heat-press the resin sheet 107 to the mounting surface 3a. The resin sheet 107 includes a first region 171 on which the electronic component 4 is placed, and a second region 172 that is provided outside the first region 171 and continuous with the first region 171 when viewed from the Y direction intersecting the mounting surface 3a when the resin sheet 107 is placed on the mounting surface 3a. In step S102, the pressure applied to the second region 172 by the pressure jig 180 is lower than the pressure applied to the first region 171 by the pressure jig 180.

Description

Technical Field

[0006] , ,

[0001] The present invention relates to a method for manufacturing an electronic component cooling structure and an electronic component cooling structure.

Background Art

[0002] Patent Document 1 describes a power module including a semiconductor chip, a heat sink for discharging heat generated by the semiconductor chip to the outside, and a composite adhesive provided between the semiconductor chip and the heat sink.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power module as described in Patent Document 1 above, an insulating resin sheet may be disposed between the heat sink and the semiconductor chip (electronic component). In this case, by crimping the resin sheet to the heat sink, bubbles in the resin sheet can be reduced to improve heat dissipation and insulation. However, for example, if the shape of the heat sink is complex, the heat sink may be deformed by the load during crimping.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing an electronic component cooling structure and an electronic component cooling structure that can improve heat dissipation and insulation while reducing the load on the heat sink.

Means for Solving the Problems

[0006] The present invention relates to a method for manufacturing an electronic component cooling structure, comprising: a heat sink having a mounting surface on which an electronic component is mounted, for dissipating heat from the electronic component; and a thermosetting resin sheet made of an insulating material and placed between the electronic component and the mounting surface, comprising: a first step of placing the resin sheet on the mounting surface; and a second step, after the first step, of applying pressure to the resin sheet toward the mounting surface using a pressure jig and heating the resin sheet to thermocompress the resin sheet toward the mounting surface, wherein the resin sheet includes a first region on which the electronic component is placed, and a second region provided outside the first region and continuously with the first region when viewed from a direction intersecting the mounting surface when the resin sheet is placed on the mounting surface, and in the second step, the pressure applied to the second region by the pressure jig is lower than the pressure applied to the first region by the pressure jig.

[0007] In this method for manufacturing an electronic component cooling structure, the second step involves applying pressure to the mounting surface of the resin sheet using a pressure jig, and heating the resin sheet to heat-press it onto the mounting surface. This reduces air bubbles within the resin sheet, improving heat dissipation and insulation, while simultaneously bonding the resin sheet to the mounting surface. The resin sheet includes a first region where the electronic components are placed, and a second region that extends continuously from the first region to the outside of it. In the first region, as described above, higher heat dissipation and insulation are required because the electronic components are placed there. On the other hand, the second region has lower requirements for heat dissipation and insulation compared to the first region. Therefore, in the second step, the pressure applied to the second region of the resin sheet is lower than the pressure applied to the first region. This reduces the load on the entire heat sink compared to applying the same pressure to the second region as to the first region, while ensuring the required heat dissipation and insulation for each region. Thus, this method for manufacturing an electronic component cooling structure can reduce the load on the heat sink while improving heat dissipation and insulation.

[0008] In the method for manufacturing an electronic component cooling structure according to the present invention, in the second step, the resin sheet may be pressurized using a pressurizing jig in which the part that pressurizes the first region protrudes from the part that pressurizes the second region toward the mounting surface, thereby making the pressurizing force in the second region lower than the pressurizing force in the first region. In this way, the pressurizing forces in the first and second regions may be controlled by utilizing the shape of the pressurizing jig.

[0009] In the method for manufacturing an electronic component cooling structure according to the present invention, in the second step, the resin sheet may be pressed using a pressurizing jig in which the part that pressurizes the second region is made of a material that is more elastically deformable than the part that pressurizes the first region, thereby making the pressurizing force in the second region lower than the pressurizing force in the first region. In this way, the pressurizing forces in the first and second regions may be controlled by utilizing the elastic deformability of the pressurizing jig.

[0010] In the method for manufacturing an electronic component cooling structure according to the present invention, the second step may involve simultaneously pressurizing and heating the resin sheet. In this case, the amount of air bubbles in the resin sheet can be effectively reduced, thereby effectively improving the heat dissipation and insulation properties of the resin sheet.

[0011] In the method for manufacturing an electronic component cooling structure according to the present invention, the resin sheet further includes a third region that is provided outside the second region and continuous with the second region when viewed from a direction intersecting the mounting surface when the resin sheet is placed on the mounting surface, and in the second step, the pressure applied to the third region by the pressure jig may be lower than the pressure applied to the second region by the pressure jig. In this case, since the pressure applied to the third region of the resin sheet is lower than the pressure applied to the second region, the load on the heat sink can be reduced compared to the case where the pressure applied to the third region is equivalent to the pressure applied to the first and second regions.

[0012] In the method for manufacturing an electronic component cooling structure according to the present invention, the second step may involve heating the resin sheet to cure it. In this case, an additional heating step is not required to further cure the resin sheet after the second step and after the electronic components have been placed on the resin sheet. Therefore, the electronic component cooling structure can be easily manufactured.

[0013] In the method for manufacturing an electronic component cooling structure according to the present invention, the second step may involve heating the resin sheet to maintain its adhesive properties. In this case, after the second step and after placing the electronic component on the resin sheet, a step is performed in which the electronic component is pressed toward the resin sheet and the resin sheet is heated to cure the resin sheet, thereby directly bonding the electronic component to the resin sheet without the use of an adhesive.

[0014] The electronic component cooling structure according to the present invention comprises a heat sink for dissipating heat from the electronic component, having a mounting surface on which the electronic component is mounted, and a resin sheet made of an insulating material disposed between the electronic component and the mounting surface, wherein the resin sheet includes a first region on which the electronic component is mounted and a second region provided outside the first region and continuously with respect to the first region when viewed from a direction intersecting the mounting surface, the thickness of the second region being greater than the thickness of the first region.

[0015] In this electronic component cooling structure, the thickness of the second region of the resin sheet is greater than the thickness of the first region of the resin sheet. In other words, the thickness of the first region is thinner than the thickness of the second region. Such a resin sheet can be created, for example, as follows: After placing the component that will become the resin sheet on the mounting surface, the component is pressed using a pressing jig so that the pressing force on the portion corresponding to the second region of the component is lower than the pressing force on the portion corresponding to the first region of the component. In this case, for the same reasons as described above, it is possible to reduce the load on the heat sink while improving heat dissipation and insulation. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a method for manufacturing an electronic component cooling structure and an electronic component cooling structure that can improve heat dissipation and insulation properties while reducing the load on the heat sink.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a schematic perspective view of a power converter including an electronic component cooling structure according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of a power converter including the electronic component cooling structure shown in FIG. 1. [Figure 3] FIG. 3 is a front view of the electronic component and the electronic component cooling structure shown in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of the electronic component and the electronic component cooling structure shown in FIG. 3. [Figure 5] FIGS. 5(a) and (b) are cross-sectional and front views showing the first step of an electronic component cooling structure according to an embodiment. [Figure 6] FIGS. 6(a) and (b) are cross-sectional views showing the second step of an electronic component cooling structure according to an embodiment. FIG. 6(a) shows the state before thermocompression bonding of the resin sheet, and FIG. 6(b) shows the state after thermocompression bonding of the resin sheet. [Figure 7] FIGS. 7(a) and (b) are cross-sectional views showing the second step of an electronic component cooling structure according to a modified example. FIG. 7(a) shows the state before thermocompression bonding of the resin sheet, and FIG. 7(b) shows the state after thermocompression bonding of the resin sheet.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of each figure, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions may be omitted. In addition, each figure may show an orthogonal coordinate system composed of an X-axis, a Y-axis, and a Z-axis.

[0019] As shown in FIGS. 1 and 2, the power converter 1 includes a base plate 2, a partition wall 3 as a heat radiator, a plurality of electronic components 4, a pressing member 5, a circuit board 6, and a resin sheet 7. The power converter 1 of the present embodiment is an inverter, a converter, or the like that converts the input power.

[0020] The base plate 2 is a plate member having a rectangular shape that serves as a base for mounting the circuit board 6 and other components constituting the power converter 1. The base plate 2 has an inner wall surface 2a and an outer wall surface 2b facing each other in the plate thickness direction (Z direction), a pair of side surfaces 2c facing each other in the Y direction perpendicular to the Z direction, and a pair of side surfaces 2e facing each other in the X direction perpendicular to the Z direction and the Y direction. In this example, the base plate 2 is formed of a metal (for example, aluminum).

[0021] The partition wall 3 is disposed near one end of the base plate 2 in the Y direction. The partition wall 3 is disposed inside the side surface 2c of the base plate 2 when viewed from the Z direction. The partition wall 3 is a member having a quadrangular prism shape. The partition wall 3 protrudes in the Z direction from the inner wall surface 2a and is integrally formed with the base plate 2. In this example, the partition wall 3 is formed of a metal (for example, aluminum). The partition wall 3 has a mounting surface 3a on which the electronic components 4 are mounted. The mounting surface 3a is a side surface parallel to the side surface 2c and faces one side in the Y direction.

[0022] A water channel 30 is provided inside the partition wall 3. The water channel 30 is a flow path through which cooling water for cooling the electronic components 4 flows. That is, the partition wall 3 is a heat sink for dissipating the heat of the electronic components 4. The water channel 30 is provided so as to extend from the partition wall 3 to the inside of the base plate 2 and is formed by being closed by a lid member 31. The base plate 2 and the partition wall 3 are provided with an introduction portion (not shown) for introducing cooling water from the outside into the water channel 30.

[0023] Multiple electronic components 4 are mounted on the mounting surface 3a of the partition wall 3 and are arranged in the X direction. The electronic components 4 are packages containing so-called power semiconductor elements (discrete elements), such as MOSFETs and IGBTs. The electronic components 4 comprise a package body 40 and multiple terminals 41 protruding from the package body 40 in the Z direction away from the base plate 2. The package body 40 is formed in the shape of a rectangular parallelepiped, and semiconductor elements and a heat sink are housed inside the package body 40.

[0024] The package body 40 is positioned so that its bottom surface 40a faces the mounting surface 3a. The package body 40 is pressed against the mounting surface 3a by the leaf spring portion 50 of the pressing member 5, which will be described later. A resin sheet 7, which will be described later, is placed between the bottom surface 40a of the package body 40 and the mounting surface 3a of the partition wall 3.

[0025] The pressing member 5 has a plurality (for example, five) leaf spring sections 50 and a fixing section 51. The plurality of leaf spring sections 50 are arranged in a line in the X direction. The leaf spring sections 50 press the electronic component 4 against the mounting surface 3a of the partition wall 3 in the Y direction. The base ends of the leaf spring sections 50 are connected to the fixing section 51.

[0026] The fixing portion 51 extends in a plate shape along the X direction. The fixing portion 51 is fastened to a boss 20 that protrudes from the mounting surface 3a in the Y direction by fasteners 52 such as screws. As a result, the pressing member 5 is fixed to the partition wall 3 in the Y direction via the boss 20. Alternatively, the boss 20 may be provided on the base plate 2 and the pressing member 5 fixed to the base plate 2.

[0027] The circuit board 6 is positioned opposite the base plate 2 in the Z direction, with the partition wall 3 in between, and is formed in a flat plate shape with the Z direction as the thickness direction. The circuit board 6 is made of an insulating material. The circuit board 6 has through-holes 6c that penetrate along the Z direction. Terminals 41 are inserted through the through-holes 6c. Terminals 41 are electrically connected to soldering lands (not shown) formed around the through-holes 6c.

[0028] Next, the electronic component cooling structure 10 according to this embodiment will be described in detail with reference to Figures 3 and 4. In Figures 3 and 4, only the electronic component 4 and the electronic component cooling structure 10 shown in Figure 1 are shown. Note that the water channel 30 of the partition wall 3 and the terminals 41 of the electronic component 4 are omitted.

[0029] The electronic component cooling structure 10 comprises a partition wall 3 and a resin sheet 7. The resin sheet 7 is positioned between the bottom surface 40a of the electronic component 4 and the mounting surface 3a of the partition wall 3. The resin sheet 7 is in contact with both the bottom surface 40a and the mounting surface 3a. The resin sheet 7 is a resin layer that has been cured and formed by thermo-pressing a thermosetting resin sheet 107 (described later) onto the mounting surface 3a. The resin sheet 7 is made of an insulating material. For example, the resin sheet 7 is made of an insulating material such as silicon to which a thermally conductive filler (such as boron nitride, aluminum nitride, or silicon nitride) has been added.

[0030] The resin sheet 7 is formed in a rectangular shape with the X direction as its longitudinal direction when viewed from the Y direction (the direction intersecting the mounting surface 3a). The thickness of the resin sheet 7 is, for example, 100 μm to 200 μm. The resin sheet 7 includes a plurality (five in this example) of first regions 71, a second region 72, and a pair of third regions 73, which are formed integrally. The plurality of first regions 71 are arranged in the X direction. The electronic component 4 is placed in the first region 71. The first region 71 overlaps with the electronic component 4 when viewed from the Y direction. That is, the first region 71 is the region directly beneath the electronic component 4. Each first region 71 is formed in a rectangular shape with the Z direction as its longitudinal direction when viewed from the Y direction.

[0031] Although not shown in the diagram, a thermal conductive material is placed between the first region 71 and the electronic component 4. The thermal conductive material is, for example, a thermal interface material (TIM) such as thermal grease and gap filler. Therefore, the electronic component 4 is pressed against the partition wall 3 via the thermal conductive material and the first region 71 by the leaf spring portion 50 of the pressing member 5. The thermal conductive material may also have an adhesive function. In this case, the electronic component 4 can be bonded to the mounting surface 3a by the thermal conductive material.

[0032] The second region 72 is located outside the first region 71 when viewed from the Y direction and is continuous with the first region 71. The second region 72 is a region for ensuring creepage distance (creepage insulation) between the partition wall 3 and the electronic component 4, and surrounds each of the first regions 71 when viewed from the Y direction. The thickness of the second region 72 is greater than the thickness of the first region 71.

[0033] The second region 72 is integrally formed by multiple frame-like portions, each enclosing one of the multiple first regions 71, arranged and continuous in the X direction. In other words, the second region 72 includes a frame portion 72a and multiple (four in this example) partition portions 72b. The frame portion 72a is formed in the shape of a rectangular frame and encloses the entirety of the multiple first regions 71. The multiple partition portions 72b are arranged in the X direction inside the frame portion 72a. Each partition portion 72b is formed in the shape of a rectangle with the Z direction as its longitudinal direction. Each partition portion 72b is positioned between a pair of adjacent first regions 71. The partition portions 72b are connected to the frame portion 72a on both sides in the Z direction.

[0034] The pair of third regions 73 are provided outside the second region 72 and are continuous with the second region 72 when viewed from the Y direction. For example, the pair of third regions 73 protrude outward from both ends of the second region 72 in the X direction. The thickness of the third region 73 is greater than the thickness of the second region 72. The third region 73 is, for example, a portion used for positioning the resin sheet 7. In the illustrated example, the third region 73 is provided with a through hole 73a through which, for example, a pin or the like is inserted.

[0035] Here, as mentioned above, the first region 71 is located directly beneath the electronic component 4, and therefore requires high heat dissipation and insulation. On the other hand, the second region 72 is located outside the electronic component 4, so the requirements for heat dissipation and insulation are lower in the second region compared to the first region 71. Furthermore, the third region is located outside the first and second regions, so the requirements for heat dissipation and insulation are even lower compared to the first and second regions 71 and 72. For this reason, the density of the insulating material constituting the resin sheet 7 is increased from the third region 73 towards the first region 71. That is, the second region 72 is denser than the third region 73, and the first region 71 is denser than the second region 72.

[0036] Next, the manufacturing method of the electronic component cooling structure according to this embodiment will be described with reference to Figures 5 and 6. In the manufacturing method of the electronic component cooling structure according to this embodiment, the above-described electronic component cooling structure 10 is manufactured.

[0037] As shown in Figures 5(a) and (b), first, the resin sheet 107 is placed on the mounting surface 3a of the partition wall 3 (step S101: first step). The resin sheet 107 is a sheet-like component that forms the basis of the resin sheet 7. In this embodiment, the thickness of the resin sheet 107 is uniform throughout the entire resin sheet 107. The thickness of the resin sheet 107 is greater than, for example, the thickness of the resin sheet 7 formed after heat bonding. The resin sheet 107 is thermosetting. The resin sheet 107 is not in a paste-like (liquid) state, but is a semi-cured resin sheet in a state where the resin has not completely hardened (stage B).

[0038] The resin sheet 107 includes a first region 171, a second region 172, and a third region 173. The first region 171, the second region 172, and the third region 173 are the origins of the first region 71, the second region 72, and the third region 73 of the resin sheet 7, respectively. That is, the first region 171 is the region where the electronic component 4 is placed. The second region 172 is provided outside the first region 171 and continuous with the first region 171 when viewed from a direction perpendicular to the mounting surface 3a (Y direction) when the resin sheet 107 is placed on the mounting surface 3a.

[0039] The third region 173 is located outside the second region 172 and is continuous with the second region 172 when viewed from a direction perpendicular to the mounting surface 3a (Y direction) when the resin sheet 107 is placed on the mounting surface 3a. In this example, the third region 173 is provided with a through hole 173a that penetrates along the Y direction. The through hole 173a corresponds to the through hole 73a in the resin sheet 7 after heat compression bonding. In step S101, when placing the resin sheet 107 on the mounting surface 3a, the resin sheet 107 may be positioned by inserting a positioning pin or the like into the through hole 173a.

[0040] After step S101, the resin sheet 107 is heat-pressed onto the mounting surface 3a (step S102: second step). In step S102, pressure is applied to the resin sheet 107 toward the mounting surface 3a using the pressure jig 180, and the resin sheet 107 is heated simultaneously.

[0041] In step S102, as shown in Figure 6(a), first, a pressure jig 180 is placed on the opposite side of the partition wall 3 from the resin sheet 107 in the Y direction. Then, as shown in Figure 6(b), the pressure jig 180 is moved toward the partition wall 3, thereby applying pressure to the resin sheet 107 toward the mounting surface 3a. At the same time, the resin sheet 107 is heated so that it hardens. As a result, the resin sheet 107 hardens and the resin sheet 7 is formed. If the electronic component 4 is to be placed after step S102, the electronic component 4 may be bonded to the resin sheet 7 using an adhesive.

[0042] Here, the pressure applied to the first region 171 is set to a pressure that can ensure the required heat dissipation (heat transfer) and insulation properties in the first region 71 after thermocompression bonding. The pressure applied to the first region 171 is, for example, about 10 MPa. By applying a high pressure to the first region 171, the number of bubbles inside the first region 171 can be further reduced. As a result, partial discharge caused by these bubbles can be suppressed, and insulation properties can be improved. In addition, by applying a high pressure to the first region 171, the first region 171 can be made thinner, thereby improving heat dissipation.

[0043] The pressurizing jig 180 has a portion 181 for pressurizing the first region 171 of the resin sheet 107, a portion 182 for pressurizing the second region 172, and a portion 183 for pressurizing the third region 173. Viewed from the Y direction, portions 181, 182, and 183 overlap with the first region 171, the second region 172, and the third region 173, respectively.

[0044] Part 181 protrudes from part 182 toward the mounting surface 3a in the Y direction. That is, the surface of part 181 toward the mounting surface 3a is located closer to the mounting surface 3a than the surface of part 182 toward the mounting surface 3a. Also, the surface of part 182 toward the mounting surface 3a is located closer to the mounting surface 3a than the surface of part 183 toward the mounting surface 3a. By applying pressure to the resin sheet 107 using a pressure jig 180 having such a shape, the pressure applied to the second region 172 is made lower than the pressure applied to the first region 171. Similarly, the pressure applied to the third region 173 is made lower than the pressure applied to the second region 172. As a result, the second region 172 is deformed to be thicker than the first region 171, and the third region 173 is deformed to be thicker than the second region 172. In other words, the density increases and the thickness decreases as you move from the third region 173 toward the first region 171.

[0045] As described above, in the manufacturing method of the electronic component cooling structure according to this embodiment, in step S102, the resin sheet 107 is pressed by the pressurizing jig 180 toward the mounting surface 3a of the partition wall 3, and the resin sheet 107 is heated, thereby thermocompressing the resin sheet 107 to the mounting surface 3a. This reduces air bubbles within the resin sheet 107, improving heat dissipation and insulation, while bonding the resin sheet 107 to the mounting surface 3a. Here, the resin sheet 107 includes a first region 171 where the electronic component 4 is placed, and a second region 172 that is provided outside the first region 171 and is continuous with the first region 171. In the first region 171, since the electronic component 4 is placed, higher heat dissipation and insulation are required. On the other hand, in the second region 172, the requirements for heat dissipation and insulation are lower compared to the first region 171. Therefore, in step S102, the pressurizing force in the second region 172 of the resin sheet 107 is lower than the pressurizing force in the first region 171. As a result, compared to applying the same pressure to the second region 172 as to the first region 171, the load on the entire partition wall 3 can be reduced while ensuring the required heat dissipation and insulation properties for each region. Therefore, this manufacturing method for electronic component cooling structures can reduce the load on the partition wall 3 while improving heat dissipation and insulation properties.

[0046] Furthermore, in the manufacturing method of the electronic component cooling structure according to this embodiment, in step S102, the resin sheet is pressurized using a pressurizing jig 180 in which part 181 protrudes from part 182 toward the mounting surface 3a, thereby making the pressurizing force of the second region 172 in the resin sheet 107 lower than the pressurizing force of the first region 171. In this way, the pressurizing forces of the first region 171 and the second region 172 may be controlled by utilizing the shape of the pressurizing jig 180.

[0047] Furthermore, in the manufacturing method of the electronic component cooling structure according to this embodiment, the resin sheet 107 is pressed and heated simultaneously in step S102. In this case, air bubbles within the resin sheet 107 can be effectively reduced, thereby effectively improving the heat dissipation and insulation properties of the resin sheet 107.

[0048] Furthermore, in the manufacturing method of the electronic component cooling structure according to this embodiment, in step S102, the pressure applied to the third region 173 by the pressure jig 180 is lower than the pressure applied to the second region 172 by the pressure jig 180. As a result, since the pressure applied to the third region 173 of the resin sheet 107 is lower than the pressure applied to the second region 172, the load on the partition wall 3 can be reduced compared to the case where the pressure applied to the third region 173 is equivalent to the pressure applied to the first region 171 and the second region 172.

[0049] Furthermore, in the manufacturing method of the electronic component cooling structure according to this embodiment, in step S102, the resin sheet 107 is heated so that it hardens. This eliminates the need for an additional heating step to further harden the resin sheet 107 after the second step and after the electronic component 4 has been placed on the resin sheet 107. Therefore, the electronic component cooling structure can be easily manufactured.

[0050] In the electronic component cooling structure 10 according to this embodiment, the thickness of the second region 72 of the resin sheet 7 is greater than the thickness of the first region 71 of the resin sheet 7. In other words, the thickness of the first region 71 is thinner than the thickness of the second region 72. Such a resin sheet 7 can be created, for example, as follows: After placing the base material for the resin sheet 7 (resin sheet 107 in this example) on the mounting surface 3a, the material is pressed using a pressing jig such that the pressing force on the portion corresponding to the second region 72 of the material is lower than the pressing force on the portion corresponding to the first region 71 of the material, thereby creating a resin sheet 7 with the above-described thickness relationship. In this case, for the same reasons as described above, the load on the partition wall 3 can be reduced while improving heat dissipation and insulation. [Differentiation]

[0051] The present invention is not limited to the embodiments and modifications described above. For example, the materials and shapes of each component are not limited to those described above, but can be made from a variety of materials and shapes. In the above embodiment, in step S102, the resin sheet 107 was pressurized using a pressurizing jig 180 in which part 181 protrudes from part 182, but it is not necessary to pressurize the resin sheet 107 using such a pressurizing jig 180.

[0052] For example, as shown in Figures 7(a) and (b), in step S102, the resin sheet 107 may be pressed using a pressurizing jig 180A in which the part 182 that pressurizes the second region 72 is made of a material that is more elastically deformable than the part 181 that pressurizes the first region 71, thereby making the pressurizing force in the second region 72 lower than the pressurizing force in the first region 71.

[0053] In this example, parts 181, 182, and 183 of the pressurizing jig 180A are made of materials that are elastically deformable, in that order. That is, part 182 is made of a material that is elastically deformable more easily than part 181, and part 183 is made of a material that is elastically deformable more easily than part 182. For example, part 181 may be made of metal, part 182 may be made of resin that is elastically deformable more easily than metal, and part 183 may be made of rubber that is elastically deformable more easily than both metal and resin. Also, the side of the mounting surface 3a of the pressurizing jig 180A is flat overall when it is separated from the resin sheet 107 (before pressurizing the resin sheet 107) (see Figure 7(a)).

[0054] Even when using such a pressurizing jig 180A, the pressurizing force in the first region 71, the second region 72, and the third region 73 can be sequentially reduced. In this way, the ease of elastic deformation of the pressurizing jig 180A can be used to control the pressurizing force in the first region 71, the second region 72, and the third region 73. Furthermore, the same relationship of elastic deformation as that of the pressurizing jig 180A may be adopted in the pressurizing jig 180 according to the above embodiment.

[0055] Furthermore, in the above embodiment, the resin sheet 107 was heated in step S102 so that it would harden. However, the resin sheet 107 may be heated so that it does not harden completely, and at least the surface of the resin sheet 107 opposite to the mounting surface 3a maintains its adhesive properties.

[0056] In this case, after step S102 and after the electronic component 4 is placed on the resin sheet 107, the resin sheet 107 is heated and hardened by applying pressure to the electronic component 4 toward the resin sheet 107, thereby performing the final hardening of the resin sheet 107 and allowing the electronic component 4 to be directly bonded to the resin sheet 107 without the use of an adhesive.

[0057] Furthermore, in the above embodiment, a resin sheet 107 with protective films attached to both sides may be used in steps S101 and S102. In this case, in step S101, one protective film is peeled off, and the resin sheet 107 is placed on the mounting surface 3a so that the peeled side faces the mounting surface 3a. Next, in step S102, heat pressing is performed with the other protective film still attached. The other protective film may be peeled off after the resin sheet 107 has completely hardened.

[0058] Furthermore, in the above embodiment, the resin sheet 107 was pressed and heated simultaneously in step S102, but the pressurization and heating of the resin sheet 107 may be performed separately. For example, the resin sheet 107 may be heated after being pressed. Also, in the above embodiment, the thickness of the resin sheet 107 does not have to be uniform throughout, and for example, the thickness may differ for the first region 171, the second region 172, and the third region 173. Also, in the above embodiment, the resin sheet 107 does not have to have a third region 173. In this case, the resin sheet 107 may be positioned in a way that does not use the third region 173. Similarly, the resin sheet 7 does not have to have a third region 73.

[0059] Furthermore, in the above embodiment, a substrate may be placed between the electronic component 4 and the leaf spring portion 50 of the pressing member 5. In this case, the electronic component 4 may be mounted on this substrate. That is, the electronic component 4 mounted on the substrate may be mounted on the mounting surface 3a such that the substrate is located on the opposite side from the mounting surface 3a. In the above embodiment, the electronic component 4 was a package including a power semiconductor element, but the electronic component 4 may be a heat-generating component such as a transformer or a coil.

[0060] The above embodiment is described below.

[0061] The method for manufacturing an electronic component cooling structure as described in the appendix may be [1] "a method for manufacturing an electronic component cooling structure comprising: a mounting surface on which an electronic component is mounted, a heat sink for dissipating heat from the electronic component, and a thermosetting resin sheet made of an insulating material and disposed between the electronic component and the mounting surface, comprising: a first step of placing the resin sheet on the mounting surface; and a second step after the first step of pressurizing the resin sheet toward the mounting surface with a pressurizing jig and heating the resin sheet to thermocompress the resin sheet toward the mounting surface, wherein the resin sheet includes a first region on which the electronic component is placed, and a second region provided outside the first region and continuously with the first region when viewed from a direction intersecting the mounting surface when the resin sheet is placed on the mounting surface, and in the second step, the pressure applied to the second region by the pressurizing jig is lower than the pressure applied to the first region by the pressurizing jig."

[0062] The method for manufacturing the electronic component cooling structure described in the appendix may be [2] "the method for manufacturing the electronic component cooling structure described in [1] above, wherein in the second step, the resin sheet is pressurized using the pressurizing jig, the portion that pressurizes the first region protrudes from the portion that pressurizes the second region toward the mounting surface, thereby making the pressurizing force in the second region lower than the pressurizing force in the first region."

[0063] The method for manufacturing the electronic component cooling structure described in the appendix may also be [3] "the method for manufacturing the electronic component cooling structure described in [1] or [2] above, wherein in the second step, the resin sheet is pressed using the pressing jig, the portion of which pressurizes the second region is made of a material that is more elastically deformable than the portion of which pressurizes the first region, thereby making the pressing force in the second region lower than the pressing force in the first region."

[0064] The method for manufacturing the electronic component cooling structure described in the appendix may be [4] "the method for manufacturing the electronic component cooling structure described in any of [1] to [3] above, wherein the second step involves simultaneously pressurizing and heating the resin sheet."

[0065] The method for manufacturing the electronic component cooling structure described in the appendix may be [5] "the method for manufacturing the electronic component cooling structure described in any of [1] to [4] above, wherein the resin sheet further includes a third region that is provided outside the second region and continuous with the second region when viewed from a direction intersecting the mounting surface when the resin sheet is placed on the mounting surface, and in the second step, the pressure applied to the third region by the pressure jig is lower than the pressure applied to the second region by the pressure jig."

[0066] The method for manufacturing the electronic component cooling structure described in the appendix may be [6] "the method for manufacturing the electronic component cooling structure described in any of [1] to [5] above, wherein in the second step, the resin sheet is heated so that the resin sheet hardens."

[0067] The method for manufacturing the electronic component cooling structure described in the appendix may be [7] "the method for manufacturing the electronic component cooling structure described in any of [1] to [5] above, wherein in the second step, the resin sheet is heated so as to maintain the adhesion of the resin sheet."

[0068] The electronic component cooling structure described in the appendix may also be [8] "an electronic component cooling structure comprising a heat sink having a mounting surface on which an electronic component is mounted, for dissipating heat from the electronic component, and a resin sheet made of an insulating material disposed between the electronic component and the mounting surface, wherein the resin sheet includes a first region on which the electronic component is mounted, and a second region provided outside the first region and continuously with the first region when viewed from a direction intersecting the mounting surface, wherein the thickness of the second region is greater than the thickness of the first region." [Explanation of Symbols]

[0069] 10... Electronic component cooling structure, 3... Heat sink, 3a... Mounting surface, 4... Electronic component, 7,107... Resin sheet, 71,171... First area, 72,172... Second area, 73,173... Third area, 180,180A... Pressurizing jig, 181,182... Part.

Claims

1. A method for manufacturing an electronic component cooling structure, comprising: a mounting surface on which an electronic component is mounted; a heat sink for dissipating heat from the electronic component; and a thermosetting resin sheet made of an insulating material and disposed between the electronic component and the mounting surface, The first step is to place the resin sheet on the mounting surface, Following the first step, a second step is performed in which the resin sheet is heat-pressed onto the mounting surface by applying pressure to the resin sheet with a pressure jig and heating the resin sheet. Equipped with, The resin sheet includes a first region on which the electronic components are arranged, and a second region that is provided outside the first region and continuous with the first region when viewed from a direction intersecting the mounting surface when the resin sheet is placed on the mounting surface. In the second step, the pressure applied to the second region by the pressurizing jig is lower than the pressure applied to the first region by the pressurizing jig. A method for manufacturing an electronic component cooling structure.

2. In the second step, the resin sheet is pressurized using the pressurizing jig, the portion that pressurizes the first region protrudes from the portion that pressurizes the second region toward the mounting surface, thereby lowering the pressurizing force in the second region to a lower pressurizing force in the first region. A method for manufacturing an electronic component cooling structure according to claim 1.

3. In the second step, the resin sheet is pressed using the pressing jig, in which the portion pressing the second region is made of a material that is more elastically deformable than the portion pressing the first region, thereby lowering the pressing force in the second region to the pressing force in the first region. A method for manufacturing an electronic component cooling structure according to claim 1.

4. In the second step described above, the pressing and heating of the resin sheet are performed simultaneously. A method for manufacturing an electronic component cooling structure according to claim 1.

5. The resin sheet, when the resin sheet is placed on the mounting surface, further includes a third region that is provided outside the second region and continuous with the second region when viewed from a direction intersecting the mounting surface, In the second step, the pressure applied to the third region by the pressurizing jig is lower than the pressure applied to the second region by the pressurizing jig. A method for manufacturing an electronic component cooling structure according to claim 1.

6. In the second step, the resin sheet is heated so that it hardens. A method for manufacturing an electronic component cooling structure according to claim 1.

7. In the second step, the resin sheet is heated so as to maintain its adhesive properties. A method for manufacturing an electronic component cooling structure according to claim 1.

8. It has a mounting surface on which electronic components are mounted, and a heat sink for dissipating heat from the electronic components, A resin sheet formed of an insulating material is placed between the electronic component and the mounting surface, Equipped with, The resin sheet includes a first region on which the electronic components are arranged, and a second region that is provided outside the first region and continuous with the first region when viewed from a direction intersecting the mounting surface. The thickness of the second region is greater than the thickness of the first region. Cooling structure for electronic components.

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