Insert molded article and method for manufacturing the same

Abstract

To provide an insert molded article capable of enhancing heat radiation efficiency even if a pressing part for pressing a heating member is not formed.SOLUTION: The insert molded article 1 of the present invention includes a heat generating member 10, heat conduction members 20, and a resin molded portion 30. The heat generating member 10 generates or transfers heat. The heat conduction members 20 are elastic members that conduct heat from the heat generating member 10 to the heat dissipating member. The resin molded portion 30 is injection-molded from a thermoplastic resin, and is integrated with the heat generating member 10 and the heat conduction members 20. Each of the heat conduction members 20 has a first main surface 21, a second main surface 22, and side surfaces 23 connecting the first main surface 21 and the second main surface 22. The first main surface 21 is in contact with the heat generating member 10, and the second main surface 22 is exposed to the outside and can be in contact with a heat radiating member. The resin molded portion 30 covers the outer peripheries of the contact portions between the first main surfaces 21 of the heat conduction members 20 and the heat generating member 10 and at least part of the side surfaces 23.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an insert-molded product provided with a thermally conductive sheet and a method for manufacturing the same. [Background technology]

[0002] Vehicles have conventionally been equipped with units that include heat-generating components such as ICs, power elements, relays, reactors, and the like. Because a relatively large current flows through these types of units, the heat-generating components generate a large amount of heat. Therefore, a configuration is needed to suppress the temperature rise of the unit by dissipating the heat generated by the heat-generating components to a heat-dissipating component such as a housing. Under these circumstances, a circuit configuration has been proposed in the past that uses a thermally conductive sheet to conduct heat from a bus bar, which is a heat-generating component, to a heat-dissipating component (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-087265 Summary of the Invention [Problem to be solved by the invention]

[0004] In the circuit assembly of the above-described prior art, a pressing portion is formed to improve the heat dissipation efficiency of the bus bar, and the bus bar is brought into contact with the thermally conductive sheet at this pressing portion. However, forming such a pressing portion results in an increase in the size and weight of the circuit assembly. One possible solution is to embed the bus bar in a molded resin part, pre-form exposure holes to expose the bus bar, and then later attach the thermally conductive sheet to the exposure holes to secure the thermally conductive sheet to the bus bar. However, this configuration makes it difficult to secure the thermally conductive sheet to the bus bar without any gaps, making it difficult to improve the heat dissipation efficiency of the bus bar (heat-generating component).

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an insert-molded product and a manufacturing method thereof that can increase heat dissipation efficiency without forming a pressing portion that presses against a heat-generating component. [Means for solving the problem]

[0006] In order to solve the above problems, the invention described in Means 1 is an insert-molded product comprising a heat-generating component that generates or transfers heat, an elastic thermally conductive material that transfers the heat from the heat-generating component to a heat-dissipating component, and a resin molded portion that is injection-molded from a thermoplastic resin and is integrated with the heat-generating component and the thermally conductive material, wherein the thermally conductive material has a first main surface, a second main surface, and a side surface that connects the first main surface and the second main surface, the first main surface contacts the heat-generating component, and the second main surface is exposed to the outside and can contact the heat-dissipating component, and the resin molded portion covers the outer periphery of the contact portion between the first main surface of the thermally conductive material and the heat-generating component and at least a part of the side surface.

[0007] Therefore, according to the invention described in Means 1, since the resin molded part integrated with the heat-generating component and the thermally conductive material is injection-molded, gaps are unlikely to form between the resin molded part and the thermally conductive material, or between the surface of the heat-generating component and the thermally conductive material. This improves the adhesion of the thermally conductive material to the heat-generating component compared to conventional techniques in which the thermally conductive material is later attached, resulting in higher heat dissipation efficiency from the heat-generating component and suppressing temperature increases. Furthermore, since the thermally conductive material can be in contact with the heat-generating component without gaps even without forming a pressing part to press the heat-generating component, the insert-molded product can be made smaller and lighter.

[0008] The invention described in means 2 is based on means 1, and is characterized in that the resin molded portion presses the first main surface of the thermally conductive material against the surface of the heat-generating member.

[0009] Therefore, according to the invention described in means 2, the adhesion of the thermally conductive material to the heat-generating member is improved, and as a result, the heat dissipation efficiency of the heat-generating member is further improved.

[0010] The invention described in means 3 is characterized in that, in means 2, the thermal conductive material has a protrusion on the side surface near the first main surface, and has a cross-sectional shape in which the length of the first main surface is longer than the length of the second main surface.

[0011] Therefore, according to the invention described in means 3, the presence of the protruding portion makes the area of ​​the first main surface larger than the area of ​​the second main surface, and increases the contact area of ​​the thermally conductive material with the heat-generating component. As a result, the heat dissipation efficiency of the heat-generating component is improved, and temperature increases can be suppressed. In addition, the formation of the protruding portion further improves the adhesion of the thermally conductive material to the heat-generating component.

[0012] The invention described in means 4 is characterized in that in any one of means 1 to 3, the hardness of the thermal conductive material measured by an Asker rubber hardness tester type C is 3 or more and 55 or less.

[0013] Therefore, according to the invention described in means 4, a thermally conductive material in this hardness range is relatively soft, so it easily deforms and adheres to the heat dissipation member when it comes into contact with the heat dissipation member. This increases the heat dissipation efficiency of the heat-generating member and suppresses temperature rise. Furthermore, because it is not too soft, it does not deform excessively due to the injection pressure during injection molding.

[0014] The invention described in means 5 is summarized as being any one of means 1 to 3, wherein the insert-molded product is a resin-coated busbar component having a structure in which the busbar, which is the heat-generating member, the thermally conductive material, and the resin molded portion are integrated together. According to the invention described in means 5, it is possible to obtain a resin-coated busbar component having a structure in which the busbar, the thermally conductive material, and the resin molded portion are integrated together.

[0015] The invention described in means 6 is characterized in that, in any one of means 1 to 3, the heat-generating component has a plurality of component surfaces that are positioned so as to intersect with each other, and the heat-conducting material is arranged in contact with at least two of the plurality of component surfaces.

[0016] Therefore, according to the invention described in means 6, by providing thermally conductive materials at a plurality of different locations, the heat dissipation efficiency of the heat-generating member is improved, and temperature rise can be efficiently suppressed.

[0017] The invention described in Means 7 is a method for manufacturing the insert molded product described in Means 1, characterized in that it includes a preparation step of setting the thermally conductive material and the heat-generating component in a mold while they are in contact with each other, and an injection molding step of injecting the molten thermoplastic resin into the mold to form the resin molded portion that covers the outer periphery of the contact area between the first main surface of the thermally conductive material and the heat-generating component and at least a part of the side surface.

[0018] Therefore, according to the invention described in Means 7, the injection pressure of the thermoplastic resin acts on the thermally conductive material during the injection molding process, making it difficult for gaps to form between the resin molded part and the thermally conductive material, and allowing the thermally conductive material to come into contact with the heat-generating component without any gaps. Therefore, it is possible to relatively easily manufacture an insert-molded product with a desired configuration.

[0019] The invention described in means 8 is characterized in that in means 7, the injection molding process is carried out while the second main surface side of the thermal conductive material is held in a positioning recess formed on the inner surface of the mold.

[0020] Therefore, according to the invention described in means 8, the thermally conductive material is held in an accurate position during injection molding, and a protruding portion corresponding to the depth of the positioning recess can be formed on the second main surface of the thermally conductive material. Furthermore, since the injection pressure of the thermoplastic resin is not applied to the inside of the positioning recess, a protruding portion with a suitable shape can be obtained. [Effects of the Invention]

[0021] As described above in detail, according to the inventions described in claims 1 to 8, it is possible to provide an insert-molded product and a manufacturing method thereof that can improve heat dissipation efficiency without forming a pressing portion that presses a heat-generating component. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a schematic perspective view showing a resin-coated bus bar component according to the embodiment; [Figure 2] A cross-sectional view corresponding to the cross section along line AA in Figure 1. [Figure 3] Cross-sectional view of line BB in Figure 2. [Figure 4] 2 is a cross-sectional view showing the mold after the preparation step, corresponding to the cross section along the line AA in FIG. 1. [Figure 5] 3 is a cross-sectional view showing the mold after the preparation step, corresponding to the cross section along the line BB in FIG. 2. [Figure 6] FIG. 4 is a cross-sectional view showing the mold after the injection molding process. [Figure 7] FIG. 2 is a plan view showing a device for measuring temperature changes of a bus bar. [Figure 8] A cross-sectional view showing the problem that occurs when a thermal conductive sheet is attached later (when the thermal conductive sheet is small). [Figure 9] A cross-sectional view showing the problem that occurs when a thermal conductive sheet is attached later (when the thermal conductive sheet is large). [Figure 10] FIG. 10 is a cross-sectional view showing a resin-coated bus bar component and an aluminum die-cast product according to another embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a reactor according to another embodiment. [Figure 12] 5A to 5C are cross-sectional views illustrating a method for manufacturing the reactor. [Figure 13] 10A and 10B are cross-sectional views showing a conventional method for manufacturing a reactor. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] As shown in FIGS. 1 and 2, the resin-coated busbar component 1 of this embodiment is an insert-molded product having a structure in which a busbar 10, which is a heat-generating component, a thermally conductive sheet 20, which is a thermally conductive material, and a resin-molded portion 30 are integrated together. The busbar 10 is strip-shaped and made of a conductive metal material (copper in this embodiment). The busbar 10 conducts electricity from one electronic component (not shown) to another electronic component and transfers heat generated in the electronic component. A first end 11 of the busbar 10 is provided with a circular first through-hole 13 penetrating the first end 11 in the thickness direction, and a second end 12 of the busbar 10 is provided with a circular second through-hole 14 penetrating the second end 12 in the thickness direction. The resin-coated busbar component 1 is housed in a resin housing component 2 (see FIG. 2). A heat sink 50 (heat dissipation member) is attached to the bottom of the resin-coated busbar component 1. Furthermore, with the first end 11 of busbar 10 overlapping the end of a busbar 15 other than busbar 10, a bolt 41 is inserted through first through hole 13 and through hole 16 of the other busbar 15, and a nut (not shown) is screwed onto the tip of the inserted bolt 41. With the second end 12 of busbar 10 overlapping the end of a busbar 17 other than busbar 10, a bolt 41 is inserted through second through hole 14 and through hole 18 of the other busbar 17, and a nut (not shown) is screwed onto the tip of the inserted bolt 41. As a result, first end 11 and second end 12 of busbar 10 are connected to the ends of the other busbars 15 and 17, respectively, allowing current to flow through busbar 10, and the busbar 10 generates heat due to the current flow. Note that the electronic component is not particularly limited, but examples include components through which a large current flows, such as power transistors and power ICs.

[0025] As shown in FIGS. 1 to 3, the thermally conductive sheet 20 is an elastic member that conducts heat from the bus bar 10 to the heat sink 50. In this embodiment, the thermally conductive sheet 20 is formed from a sheet made of a non-silicone acrylic resin (Hypersoft Heat Dissipation Sheet 6550H, manufactured by 3M Japan Ltd.). The thermal conductivity of the thermally conductive sheet 20 is 3.0 W / m·K. The hardness of the thermally conductive sheet 20, as measured with an Asker rubber hardness tester, type C (not shown), is not particularly limited, but may be, for example, 3 or more and 55 or less, and may particularly be 5 or more and 35 or less.

[0026] The thermally conductive sheet 20 has one first main surface 21, one second main surface 22, and four side surfaces 23 connecting the first main surface 21 and the second main surface 22. The first main surface 21 is in contact with the surface 10a of the busbar 10. Meanwhile, the second main surface 22 is exposed to the outside of the resin molded portion 30 (busbar resin-coated component 1) and is capable of contacting the heat sink 50. The thermally conductive sheet 20 also has protruding portions 24 on each side surface 23 near the first main surface 21. The protruding amount of the protruding portion 24 from the side surface 23 gradually increases as it approaches the first main surface 21. That is, the thermally conductive sheet 20 has a cross-sectional shape in which the vertical and horizontal lengths of the first main surface 21 are longer than the vertical and horizontal lengths of the second main surface 22. Therefore, the area of ​​the first main surface 21 is larger than the area of ​​the second main surface 22. Either the vertical or horizontal length of the first main surface 21 may be longer than either the vertical or horizontal length of the second main surface 22.

[0027] As shown in FIGS. 1 to 3, the resin molded portion 30 is formed by injection molding the bus bar 10 and the thermally conductive sheet 20 set in a mold 60 (see FIGS. 4 and 5). The resin molded portion 30 is not particularly limited as long as it is a thermoplastic resin, but examples of the resin molded portion 30 that can be used include engineering plastics such as PBT resin (polybutylene terephthalate resin), PA resin (polyamide resin), and PPS resin (polyphenylene sulfide resin). The resin molded portion 30 is preferably made of PPS resin, which has good heat resistance. The resin molded portion 30 is integrated with the bus bar 10 and the thermally conductive sheet 20.

[0028] As shown in FIGS. 2 and 3 , the resin molded portion 30 covers the rear surface 10b of the busbar 10, excluding the ends 11 and 12. The resin molded portion 30 also covers the surface 10a of the busbar 10, excluding the ends 11 and 12, on the outer periphery of the contact area with the first main surface 21 of the thermally conductive sheet 20. The resin molded portion 30 covering the surface 10a of the busbar 10 is in contact with four side surfaces 23 of the thermally conductive sheet 20. This allows the resin molded portion 30 to form a sheet holding hole 31 that is rectangular in plan view and holds the thermally conductive sheet 20 with the first main surface 21 in contact with the busbar 10 and the second main surface 22 exposed to the outside. The thermally conductive sheet 20 is thus surrounded by the resin molded portion 30, ensuring reliable support. The opening edge O of the sheet holding hole 31 (see FIG. 3 ) has a rounded, curved cross-sectional shape. Furthermore, the resin molded portion 30 covers at least a portion of the side surface 23 of the thermally conductive sheet 20, specifically, an area including the portion where the protrusion 24 is formed. The resin molded portion 30 presses the first main surface 21 of the thermally conductive sheet 20 against the front surface 10a of the busbar 10. As shown in FIG. 3 , the resin molded portion 30 covers the back surface 10b of the busbar 10, the end surface 10c of the busbar 10, and both side portions of the front surface 10a of the busbar 10. That is, the resin molded portion 30 holds the busbar 10, thereby improving the fixing strength of the busbar 10.

[0029] As shown in FIG. 3 , the thickness Y1 of the thermally conductive sheet 20 is greater than the thickness X1 of the molded resin portion 30 covering the surface 10a of the busbar 10. This causes a portion of the thermally conductive sheet 20 to protrude from the molded resin portion 30. In this case, the protruding portion of the thermally conductive sheet 20 can be deformed to ensure that the thermally conductive sheet 20 is in close contact with the heat sink 50. Since the shorter the distance from the busbar 10 to the heat sink 50, the more efficient the heat dissipation. Therefore, it is preferable that the thickness of the thermally conductive sheet 20 is as thin as possible and set to a thickness such that a portion of the thermally conductive sheet 20 protrudes from the surface of the molded resin portion 30. Note that, because the molded resin portion 30 is formed by injection molding of a thermoplastic resin, the thickness X1 of the molded resin portion 30 covering the busbar 10 is preferably at least 1 mm, and more preferably 2 mm or more.

[0030] Next, a mold 60 for molding the resin-coated bus bar component 1 will be described.

[0031] As shown in FIGS. 4 and 5 , the mold 60 includes an upper mold 61 and a lower mold 62. The upper mold 61 is disposed above the lower mold 62. A resin molded portion recess 63 for molding the resin molded portion 30 that covers the rear surface 10 b of the bus bar 10 is formed at a predetermined position on the inner surface of the upper mold 61. Meanwhile, a resin molded portion recess 65 for molding the resin molded portion 30 that covers the front surface 10 a of the bus bar 10 is formed at a predetermined position on the inner surface of the lower mold 62. Furthermore, a positioning recess 66 for positioning the thermally conductive sheet 20 is formed at a predetermined position on the bottom surface of the resin molded portion recess 65. Note that by driving at least one of the upper mold 61 and the lower mold 62 upward and downward, the upper mold 61 and the lower mold 62 can be moved toward and away from each other. When the mold 60 is closed (see Figures 4 and 5), the resin molding recess 63 of the upper mold 61 and the resin molding recess 65 of the lower mold 62 face each other, thereby forming a cavity C1 for molding the resin molded portion 30.

[0032] Next, a method for manufacturing the resin-coated bus bar component 1 using the above-described mold 60 will be described.

[0033] First, a conductive plate material (a copper plate in this embodiment) is punched out by press working or the like to form bus bar 10. When forming bus bar 10, first through holes 13 and second through holes 14 are also formed. Note that instead of performing press working or the like on the conductive plate material, bus bar 10 may be formed by cutting the conductive plate material. Alternatively, heat conduction sheet 20 is formed by cutting and processing a sheet made of a non-silicone acrylic resin into a predetermined shape.

[0034] Next, a preparation step is performed, in which the thermally conductive sheet 20 and the bus bar 10 are set in a mold 60 in a state in which they are in contact with each other (see FIGS. 4 and 5). Specifically, an upper mold 61 and a lower mold 62 constituting the mold 60 are opened, and the second main surface 22 of the thermally conductive sheet 20 is held in a positioning recess 66 of the lower mold 62. Next, a pin 67 (see FIG. 4) protruding from the lower mold 62 is inserted into the first through hole 13 and the second through hole 14 of the bus bar 10. At this time, a part of the surface 10a of the bus bar 10 comes into contact with the first main surface 21 of the thermally conductive sheet 20. Then, the upper mold 61 and the lower mold 62 are closed together to form a cavity C1 for molding the resin molded portion 30.

[0035] In the subsequent injection molding process, molten thermoplastic resin is injected into the cavity C1 through a gate 64 provided in the upper mold 61 (see FIG. 6). The injection molding process is performed with the second main surface 22 of the thermally conductive sheet 20 held in the positioning recess 66. At this time, the injection pressure of the thermoplastic resin causes the thermoplastic resin injected into the cavity C1 to press the back surface 10b of the bus bar 10 toward the lower mold 62, and the bus bar 10 presses the thermally conductive sheet 20. As the thermoplastic resin presses the side surfaces 23 of the thermally conductive sheet 20, the thermally conductive sheet 20 is pressed and deformed. As a result, the first main surface 21 side of the thermally conductive sheet 20 deforms outward, and protrusions 24 are formed on each side surface 23 in the vicinity of the first main surface 21. Next, the thermoplastic resin is cooled and solidified, so that the thermoplastic resin becomes a resin molded portion 30 that covers the back surface 10b of the busbar 10, the outer periphery of the contact area with the thermal conduction sheet 20 on the front surface 10a of the busbar 10, and at least a portion of the side surface 23.

[0036] Thereafter, the upper mold 61 and the lower mold 62 are opened to obtain the resin-coated busbar component 1. At this time, the thermoplastic resin is further cooled and contracts, causing the opening edge O of the sheet holding hole in the resin molding portion 30 to assume a rounded, curved cross-sectional shape (see FIG. 3). Then, by bringing the protruding portion of the thermally conductive sheet 20 on the second main surface 22 side into contact with the heat sink 50 and deforming it, the contact area between the thermally conductive sheet 20 and the heat sink 50 increases, making it possible to transfer heat from the busbar 10 to the heat sink 50 via the thermally conductive sheet 20.

[0037] Since the opening edge O of the sheet holding hole 31 has a rounded, curved cross-sectional shape, the opening edge O has no corners and is less likely to scratch or damage the thermally conductive sheet 20. However, the opening edge O of the sheet holding hole 31 does not necessarily have to have a rounded, curved cross-sectional shape.

[0038] Next, the evaluation method and results of the resin-coated bus bar components will be described.

[0039] First, measurement samples were prepared as follows. A busbar resin-coated component 100 (see FIG. 7) in which a thermally conductive sheet 105 was insert-molded using a mold, i.e., the same busbar resin-coated component 100 as in the above-described embodiment, was prepared and designated as an Example. A busbar resin-coated component was also prepared by embedding a busbar in a resin-molded portion, forming an exposure hole for exposing the busbar, and then later attaching a thermally conductive sheet 105 to the exposure hole, and designated as a Comparative Example. Then, the thermally conductive sheet 105 of each of the Example and Comparative Example was brought into contact with a heat sink 101 (see FIG. 7). Note that, for each measurement sample (Example and Comparative Example), a 300 mm2 area was used. 2 The thermally conductive sheet 105 used had the same shape as the above.

[0040] Next, for each measurement sample, both ends of the busbar 102 of the example and comparative example were heated by heat source 103 under the same conditions. Then, the temperature of one end of the busbar 102 was measured with thermocouple 104, and the temperature change from room temperature was compared (see FIG. 7). In addition, the temperature of the busbar 102 of the example and comparative example was measured and the temperature change from room temperature was compared for each measurement sample in which the hardness of the thermally conductive sheet 105 measured with an Asker rubber hardness tester type C was "5" and each measurement sample in which the hardness of the thermally conductive sheet 105 measured with an Asker rubber hardness tester type C was "30". The relationship between the hardness of the thermally conductive sheet 105 and the temperature change in the example and comparative example is shown in Table 1. [Table 1]

[0041] As a result, when the hardness of thermally conductive sheet 105 was "5," the temperature change of busbar 102 in the comparative example was 31.8°C, while the temperature change of busbar 102 in the example was 26.4°C. Furthermore, when the hardness of thermally conductive sheet 105 was "30," the temperature change of busbar 102 in the comparative example was 29.1°C, while the temperature change of busbar 102 in the example was 26.5°C. From the above, it was confirmed that, for each hardness of thermally conductive sheet 105, insert-molding thermally conductive sheet 105 can suppress the temperature rise of busbar 102 more effectively than post-molding.

[0042] That is, the area is 300 mm 2 When the thermally conductive sheet 105 is insert-molded, the thermally conductive sheet 105 is pressed by the thermoplastic resin injected into the mold and deformed, so that the contact area between the bus bar 102 and the thermally conductive sheet 105 is 420 mm 2 This increases to about 1.4 times the amount before deformation. From the above, it is considered that the heat from a large amount of busbar 102 is transferred to thermally conductive sheet 105, and the amount of heat dissipated from busbar 102 increases.

[0043] Therefore, according to this embodiment, the following effects can be obtained.

[0044] (1) In the conventional technology of Patent Document 1 in which the thermally conductive sheet 20 is later attached to the busbar 10, if the thermally conductive sheet 20 is small (see FIG. 8), the contact area between the thermally conductive sheet 20 and the busbar 10 becomes small, resulting in reduced heat dissipation efficiency. Also, if the thermally conductive sheet 20 is large (see FIG. 9), the thermally conductive sheet 20 does not fit into the exposure hole 111, creating a gap between the thermally conductive sheet 20 and the busbar 10, which also reduces heat dissipation efficiency.

[0045] On the other hand, in the busbar resin-coated component 1 of this embodiment, the resin molded portion 30 integrated with the busbar 10 and the thermally conductive sheet 20 is injection-molded, so that gaps are unlikely to form between the resin molded portion 30 and the thermally conductive sheet 20 or between the surface 10a of the busbar 10 and the thermally conductive sheet 20. This improves the adhesion of the thermally conductive sheet 20 to the busbar 10 compared to when the thermally conductive sheet 20 is attached to the busbar afterward, resulting in higher heat dissipation efficiency of the busbar 10 and suppression of temperature rise. Furthermore, even without forming a pressing portion that presses the busbar 10, the thermally conductive sheet 20 can be brought into contact with the busbar 10 without any gaps, allowing the busbar resin-coated component 1 to be made smaller and lighter while maintaining its heat dissipation efficiency.

[0046] (2) In the injection molding process of this embodiment, the thermoplastic resin injected into the cavity C1 presses the busbar 10 toward the thermally conductive sheet 20. As the thermoplastic resin presses against the side surfaces 23 of the thermally conductive sheet 20, the thermally conductive sheet 20 is pressed and deformed, forming protrusions 24 on each side surface 23. That is, since it is not necessary to use additional material (a sheet made of acrylic resin) for forming the thermally conductive sheet 20 to provide the protrusions 24, the amount of sheet used can be reduced. Furthermore, the thermally conductive sheet 20 can be prevented from coming off the resin molded portion 30.

[0047] The above embodiment may be modified as follows.

[0048] As shown in FIG. 10 , a busbar 71 included in a resin-coated busbar component 70 may be L-shaped, with two surfaces 72 that intersect (here, perpendicular to) each other. A thermally conductive sheet 20 may be disposed in contact with each of the surfaces 72. The second main surface 22 of each thermally conductive sheet 20 is capable of contacting an L-shaped aluminum die-cast product 73 (heat dissipation component) that also functions as a heat sink. In this case, by providing the thermally conductive sheets 20 on each of the two different surfaces 72, heat can be dissipated (cooled) from both surfaces 72, significantly suppressing temperature rise. Of course, the thermally conductive sheets 20 may be disposed in contact with multiple positions on the same surface 72. Note that a busbar may have three or more surfaces that intersect each other. In this case, the thermally conductive sheets 20 are disposed in contact with at least two of the surfaces. Furthermore, the thermally conductive sheets 20 may be disposed on two different surfaces of a rectangular heat-generating component (heat-generating member), for example.

[0049] In the above embodiment, the resin-coated busbar component 1 is used as an example of an insert-molded product, but this is not limiting. For example, a reactor 80 shown in FIG. 11 may be used as the insert-molded product. Specifically, the reactor 80 includes a core (not shown) and a coil 81 (heat-generating member) disposed around the core. The coil 81 is a substantially rectangular tubular coil formed by spirally winding a wire 82. The reactor 80 also includes a resin-molded portion 83 with a substantially U-shaped cross section that covers and integrates the core and the coil 81. The reactor 80 also includes a heat-conducting sheet 90 (thermal conductive material) that conducts heat from the coil 81 to an aluminum die-cast product 84 (heat dissipation member). A first main surface 91 of the heat-conducting sheet 90 is inserted into a sheet-retaining hole 85 formed in the resin-molded portion 83 and is in contact with the surface of the coil 81. A second main surface 92 of the heat-conducting sheet 90 is in contact with the aluminum die-cast product 84. Furthermore, the reactor 80 is attached to the aluminum die-cast product 84 by inserting a plurality of bolts 87 into through holes (not shown) in the protruding portion 86 that protrudes outward from the lower end of the resin molded portion 83, and then inserting the tip ends of the inserted bolts 87 into through holes (not shown) in the aluminum die-cast product 84 and screwing nuts (not shown) onto the tip ends of the bolts 87.

[0050] In a conventional method, the thermally conductive sheet 90 is placed below the coil 81 and then fastened with bolts 87 and nuts to deform the thermally conductive sheet 90 and fill the gap between the coil 81 and the thermally conductive sheet 90 (see FIG. 13 ). In contrast, the reactor 80 of the present invention is manufactured through a preparation process in which the thermally conductive sheet 90 and the coil 81 are placed in contact with each other and set in a mold (not shown), and an injection molding process in which molten thermoplastic resin is injected into the mold to form a resin molded portion 83 that covers the outer periphery of the contact portion between the thermally conductive sheet 90 and the coil 81 and the surface of the coil 81. In the injection molding process, the thermally conductive sheet 90 is deformed by the injection pressure of the thermoplastic resin when forming the resin molded portion 83, thereby filling the gap between the coil 81 and the thermally conductive sheet 90 (see FIG. 12 ). In this case, the gap between the coil 81 and the thermally conductive sheet 90 can be filled without fastening with bolts 87 and nuts, so that the tightening force of the bolts 87 does not need to be excessively large.

[0051] In the above embodiment, the bus bar resin-coated component 1 is exemplified as an insert-molded component, but other components such as a ferrite core insert resin component may also be used as the insert-molded component. Furthermore, the insert-molded component may be mounted on or connected to another housing such as an ECU (electronic control unit) case.

[0052] Next, in addition to the technical ideas set forth in the claims, the technical ideas grasped by the above-described embodiments will be listed below.

[0053] (1) In claim 7, the method for manufacturing an insert molded product is characterized in that, in the injection molding process, as a portion of the thermoplastic resin injected into the mold penetrates into the side surface of the thermal conductive material, the thermal conductive material is pushed and deformed, resulting in the formation of a protrusion on the side surface of the thermal conductive material at a position near the first main surface. [Explanation of symbols]

[0054] 1,70...Busbar resin-coated parts as insert molding products 10,71... Busbar as a heat-generating component 10a...Surface of heat-generating member 20,90...Thermal conductive sheet as a thermal conductive material 21,91...First main surface 22,92...Second main surface 23...Side 24...Protrusion 30,83…Resin molding part 50...Heat sink as a heat dissipation component 60...Mold 66... ​​Positioning recess 72...Component surface 73, 84...Aluminum die-cast products as heat dissipation materials 80...Reactor as an insert molding product 81...Coil as a heat generating member

Claims

1. a heat generating member that generates or transmits heat; an elastic heat-conducting material that conducts heat from the heat-generating component to a heat-dissipating component; a resin molded portion that is injection molded from a thermoplastic resin and is integrated with the heat generating member and the heat conducting material; An insert molding product comprising: the thermally conductive material has a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface; the first main surface is in contact with the heat-generating member, and the second main surface is exposed to the outside and is capable of contacting the heat-dissipating member; The resin molded portion covers an outer periphery of a contact portion between the first main surface of the thermally conductive material and the heat-generating component, and at least a part of the side surface. An insert molded product characterized by:

2. 2. The insert-molded product according to claim 1, wherein the resin molded portion presses the first main surface of the thermally conductive material against a surface of the heat-generating member.

3. The insert-molded product according to claim 2, characterized in that the thermal conductive material has a protruding portion on the side surface near the first main surface, and has a cross-sectional shape in which the length of the first main surface is longer than the length of the second main surface.

4. 4. The insert-molded product according to claim 1, wherein the hardness of the thermally conductive material measured by an Asker rubber hardness tester, type C, is 3 or more and 55 or less.

5. 4. The insert-molded product according to claim 1, wherein the insert-molded product is a bus bar resin-coated part having a structure in which the bus bar, which is the heat-generating member, the thermally conductive material, and the resin-molded portion are integrated together.

6. the heat generating member has a plurality of member surfaces that are positioned so as to intersect with each other, The thermally conductive material is disposed in contact with at least two of the surfaces of the plurality of members.

4. The insert molded product according to any one of claims 1 to 3.

7. A method for manufacturing the insert molded product according to claim 1, a preparation step of setting the heat conductive material and the heat generating component in a mold while they are in contact with each other; an injection molding process of injecting the molten thermoplastic resin into the mold to form the resin molded portion that covers an outer periphery of a contact portion between the first main surface of the thermal conductive material and the heat-generating component and at least a part of the side surface; A method for producing an insert molded product, comprising:

8. 8. The method for manufacturing an insert-molded product according to claim 7, wherein the injection molding step is performed in a state in which the second main surface side of the thermally conductive material is held in a positioning recess formed on the inner surface of the mold.

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