Electronic apparatus

Abstract

To provide an electronic apparatus that improves heat dissipation of a heating member, while preventing contact between a terminal and a heat dissipation member without applying processing to the heat dissipation member.SOLUTION: An electronic apparatus 1 comprises: a substrate 3 that has an upper surface 3a and a lower surface 3b in a front-and-back relationship and a through hole 31 connecting the surfaces; a terminal 4; a heating member 5 that is mounted on the lower surface 3b; and a heat dissipation member 8 that is arranged opposite to the lower surface 3b. The terminal 4 is inserted into the through hole 31 of the substrate 3 from a side of the upper surface 3a. The heat dissipation member 8 has a higher thermal conductivity than that of the substrate 3 and is thermally connected to the heating member 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electronic device having terminals connected to a substrate on which a heat-generating component is mounted. [Background technology]

[0002] Conventional electronic devices of this type include, for example, the one described in Patent Document 1. The electronic device described in Patent Document 1 has a structure in which a plurality of heat-generating components, such as CPUs and integrated circuit elements, are mounted on a circuit board, and press-fit terminals are inserted into through holes provided in the circuit board and held in place by press-fit. CPU is an abbreviation for Central Processing Unit. In this electronic device, a heat dissipation member, such as a heat pipe, is connected to the press-fit terminal, enabling heat dissipation through the press-fit terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-283154 Summary of the Invention [Problem to be solved by the invention]

[0004] This type of electronic device may be configured, for example, such that a circuit board on which a heat-generating component is mounted is placed on a heat-dissipating component such as a housing, and heat from the heat-generating component is dissipated to the housing via the circuit board while preventing direct contact between the terminals, such as press-fit terminals, and the housing. The heat dissipation properties of an electronic device configured in this way can be further improved by, for example, placing a heat-dissipating gel between the circuit board and the heat-dissipating component.

[0005] However, in an electronic device with the above structure, it is necessary to form a recess such as a recess or a step in the heat dissipation member in the area directly below the terminal so that the portion of the terminal that protrudes from the through hole in the circuit board does not come into contact with the heat dissipation member. Furthermore, if a recess is formed in the heat dissipation member, the heat dissipation gel placed between the circuit board and the heat dissipation member may sink into the recess, reducing the heat dissipation performance of the terminal.

[0006] In view of the above, an object of the present disclosure is to provide an electronic device in which contact between a terminal and a heat dissipation member is suppressed without processing the heat dissipation member, and in which the heat dissipation performance of the heat-generating member is improved. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, an electronic device includes: a substrate (3) having an upper surface (3a) and a lower surface (3b) that are opposite surfaces, a through hole (31) connecting the upper surface and the lower surface, and a conductive film (32) covering the wall surface of the through hole; a terminal (4) inserted into the through hole from the top surface side; A heat generating member (5, 9, 10, 11, 12, 41) mounted on the underside; The heat dissipation member (8) is disposed opposite the lower surface, has higher thermal conductivity than the substrate, and is thermally connected to the heat-generating member.

[0008] This electronic device has a structure in which terminals are inserted from the top side into through holes in a substrate having an upper surface and a lower surface, and a heat-generating component is mounted on the lower surface, thermally connected to a heat dissipation component facing the lower surface. Therefore, compared to conventional structures in which a heat-generating component is mounted on the top surface, this electronic device has a shorter distance between the heat-generating component and the heat dissipation component, improving heat dissipation. Furthermore, by mounting the heat-generating component on the lower surface of this electronic device, a gap at least equal to the height of the heat-generating component is secured between the lower surface and the heat dissipation component, preventing the portions of the terminals that protrude from the through holes to the lower surface from contacting the heat dissipation component. Therefore, this electronic device does not require a recess in the heat dissipation component to prevent contact with the terminals.

[0009] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view showing an outline of an electronic device according to a first embodiment. [Figure 2] 2 is a cross-sectional view showing the vicinity of a portion where a terminal is inserted in the electronic device of the first embodiment. FIG. [Figure 3] 10A and 10B are diagrams showing the results of thermal analysis of the electronic devices of the comparative example and the example. [Figure 4] FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing a modified example of the electronic device of the first embodiment. [Figure 5] FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing an electronic device according to a second embodiment. [Figure 6] FIG. 3 is a cross-sectional view corresponding to FIG. 2 and showing an electronic device according to a third embodiment. [Figure 7] 10A and 10B are front views showing examples of the shape of the terminal cover as viewed from the underside of the board. [Figure 8] 10A and 10B are front views showing other examples of the shape of the terminal cover as viewed from the underside of the board. [Figure 9] 10A and 10B are front views showing other examples of the shape of the terminal cover as viewed from the underside of the board. [Figure 10] FIG. 10 is a cross-sectional view corresponding to FIG. 2, showing an electronic device according to a fourth embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a first modified example of the conductive cylinder in the electronic device of the fourth embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a second modified example of the conductive cylinder in the electronic device of the fourth embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing a third modified example of the conductive cylinder in the electronic device of the fourth embodiment. [Figure 14] FIG. 13 is a front view showing a fourth modified example of the conductive tube in the electronic device of the fourth embodiment. [Figure 15]FIG. 11 is a front view showing a fifth modified example of the conductive tube in the electronic device of the fourth embodiment. [Figure 16] FIG. 10 is a cross-sectional view showing a sixth modified example of the conductive cylinder in the electronic device of the fourth embodiment. [Figure 17] FIG. 11 is a cross-sectional view showing the vicinity of a filling member in an electronic device according to a fifth embodiment. [Figure 18] 10A and 10B are front views showing examples of the shape of a filling member as viewed from the lower surface side of the substrate. [Figure 19] FIG. 10 is a cross-sectional view corresponding to FIG. 2, showing an electronic device according to a sixth embodiment. [Figure 20] FIG. 10 is a cross-sectional view corresponding to FIG. 2, showing a first modified example of the electronic device of the sixth embodiment. [Figure 21] FIG. 10 is a cross-sectional view corresponding to FIG. 2, showing a second modified example of the electronic device according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, identical or equivalent parts will be denoted by the same reference numerals.

[0012] (First embodiment) An electronic device 1 according to a first embodiment will be described. In Fig. 1, the outline of a heat generating member 5 mounted on a lower surface 3b of a substrate 3 (to be described later) is indicated by a broken line.

[0013] [Basic configuration] As shown in FIG. 1 , the electronic device 1 of this embodiment includes an upper housing 2, a substrate 3, terminals 4, a heat-generating member 5, electronic components 6, a heat dissipation material 7, and a lower housing 8. As shown in FIG. 2 , the electronic device 1 includes a substrate 3 housed in an internal space defined by the upper housing 2 and the lower housing 8, and the terminals 4 are inserted through a connector 21 of the upper housing 2. The heat-generating member 5 is mounted on the surface of the substrate 3 facing the lower housing 8, and the heat-generating member 5 and the lower housing 8 are thermally connected through the heat dissipation material 7. The electronic device 1 is suitable for use in a control device for an electrical component that generates a large current when driven, such as various ECUs for automotive applications, but can also be used for other purposes. ECU stands for Electronic Control Unit.

[0014] The upper housing 2 is made of, for example, any resin material, and is a member that covers the substrate 3 and the heat-generating component 5 and electronic components 6 mounted thereon. The upper housing 2 is formed with, for example, a plurality of connecting sections 21 each having an opening 211 into which a terminal 4 or the like connected to the substrate 3 can be inserted, and is configured to cover the top surface 3a side of the substrate 3 while allowing other components to be connected to the substrate 3. The upper housing 2 has, for example, a fastening section such as a mating claw (not shown), and is configured to be attachable to the lower housing 8.

[0015] The substrate 3 is a plate-like member having an upper surface 3a and a lower surface 3b, which are opposite surfaces, and is also referred to as a printed circuit board or a circuit board. The substrate 3 has a base made of an insulating material, such as glass epoxy resin, and has a plurality of through holes 31 connecting the upper surface 3a and the lower surface 3b. As shown in FIG. 2, the substrate 3 has a conductive film 32 covering the inner wall surfaces of the through holes 31 and wiring 33. The conductive film 32 is made of an electrically conductive material, such as copper, and covers the inner wall surfaces of the through holes 31 as well as the areas of the upper surface 3a and the lower surface 3b near the through holes 31, and is connected to the wiring 33. The wiring 33 includes, for example, upper surface wiring 331 formed on the upper surface 3a, internal wiring 332 formed inside the substrate 3, and lower surface wiring 333 formed on the lower surface 3b. The wiring 33 is formed using an electrically conductive material using a known wiring formation technique and can be in any pattern shape. The substrate 3 has, for example, terminals 4 inserted into through holes 31, a plurality of electronic components 6 mounted on the upper surface 3a side, and a heat-generating member 5 mounted on the lower surface 3b side. The substrate 3 has, for example, screw holes (not shown) provided near the four corners, and is attached to the lower housing 8 with screws (not shown), while the areas of the lower surface 3b other than those near the screw holes do not come into contact with the lower housing 8.

[0016] The terminals 4 are well-known terminals such as press-fit terminals, and are inserted into through-holes 31 in the substrate 3 from the top surface 3a through openings 211 in the upper housing 2. For example, multiple terminals 4 are inserted into the substrate 3, and are electrically connected to the heat-generating component 5 and the electronic components 6 via conductive films 32 and top-surface wiring 331 or bottom-surface wiring 333. For example, the tip portions of the terminals 4 protrude from the through-holes 31 toward the bottom surface 3b, and are thermally connected to the lower housing 8 via heat dissipation material 7. The terminals 4 do not contact the lower housing 8 and are electrically insulated from the lower housing 8. The portions of the terminals 4 protruding from the bottom surface 3b of the substrate 3 are called protruding portions 41, and the protruding portions 41 have a height that is, for example, at least less than the height of the heat-generating component 5, so that they do not come into direct contact with the lower housing 8.

[0017] The heat-generating member 5 is a power semiconductor module having semiconductor components, such as MOSFETs and IGBTs, that generate a large current when driven. MOSFETs and IGBTs are abbreviations for Metal Oxide Semiconductor Field Effect Transistor and Insulated Gate Bipolar Transistor, respectively. The heat-generating member 5 is mounted on the lower surface 3b of the substrate 3, connected to the lower surface wiring 333 via a bonding material 55 made of a conductive bonding material such as solder, and electrically connected to the terminals 4. The heat-generating member 5 is disposed, for example, separated from the lower housing 8 by a gap and thermally connected to the lower housing 8 via a heat dissipation material 7. This allows heat generated by the heat-generating member 5 when driven to be efficiently conducted to the lower housing 8 via the heat dissipation material 7, thereby suppressing temperature rise.

[0018] As shown in FIG. 2 , the heat-generating member 5 includes, for example, a lead frame 51, a semiconductor element 52, a conductive clip 53, and a sealing resin 54. The heat-generating member 5 includes, for example, the semiconductor element 52 mounted on the lead frame 51, and a plate-shaped conductive clip 53 connected to the surface of the semiconductor element 52 opposite the lead frame 51. The heat-generating member 5 has, for example, a structure in which the surface of the lead frame 51 opposite the semiconductor element 52 is exposed from the sealing resin 54, and the semiconductor element 52 and the conductive clip 53 are covered by the sealing resin 54. Alternatively, the heat-generating member 5 may have a structure in which only a portion of the conductive clip 53 is exposed from the sealing resin 54. The heat-generating member 5 has, for example, an nin1 structure in which n semiconductor elements 52 are enclosed within the sealing resin 54, where n is the number of semiconductor elements 52 (n: an integer greater than or equal to 1). The lead frame 51 is made of any conductive material, such as copper, and has a predetermined pattern shape. The semiconductor element 52 is, for example, a power semiconductor element manufactured by a known semiconductor manufacturing process, such as a power MOSFET, and at least one is mounted on the lead frame 51. The conductive clip 53 is made of any conductive material, such as copper, and is a bridging member that bridges and electrically connects the semiconductor element 52 to a part of the lead frame 51, and may also be called a metal clip. The sealing resin 54 is made of any insulating resin material, such as epoxy resin, and is a member that covers the semiconductor element 52 and the like.

[0019] A plurality of electronic components 6 are mounted on the upper surface 3a of the substrate 3, for example, and are electrically connected to the upper surface wiring 331 via bonding materials 61 made of a conductive bonding material such as solder. The electronic components 6 are various elements that can be used in electronic circuits, such as power relays, coils, electrolytic capacitors, motor relays, microcomputers, control ICs, resistors, and bus bars. IC is an abbreviation for Integrated Circuit.

[0020] The heat dissipation material 7 is a material that, for example, fills a part of the gap between the underside 3b of the substrate 3 and the lower housing 8, thereby thermally connecting at least a part of the substrate 3 and the heat-generating component 5 to the lower housing 8 and dissipating heat from the substrate 3 and the heat-generating component 5 to the lower housing 8. The heat dissipation material 7 is electrically insulating and has a thermal conductivity higher than that of air, and is made of, for example, a known heat dissipation gel, heat dissipation sheet, or heat dissipation adhesive. The heat dissipation material 7 is arranged, for example, to fill the gap between the lower housing 8 and the region of the substrate 3 that generates a large amount of heat when driven and the heat-generating component 5. The heat dissipation material 7 is also arranged, for example, to fill the gap between the terminal 4 and the lower housing 8, providing a thermal conduction path that dissipates heat from the terminal 4 to the lower housing 8.

[0021] The lower housing 8 is a member that forms a pair with the upper housing 2 and that covers the lower surface 3b side of the substrate 3. The lower housing 8 is made of, for example, a metal material such as aluminum or an alloy thereof, or a metal-resin composite material such as a highly heat-dissipating resin material containing a heat-dissipating filler, and is a heat-dissipating member that plays a role in dissipating heat from the substrate 3 and the heat-generating member 5 to the outside. The lower housing 8 may have any heat-dissipating structure, such as a heat-dissipating fin (not shown), to enhance heat dissipation.

[0022] The above is the basic configuration of the electronic device 1 of this embodiment.

[0023] [Heat dissipation] Next, the effect of improving heat dissipation by the structural model of the electronic device 1 (hereinafter referred to as the "embodiment") will be explained based on the results of thermal analysis in comparison with the structural model of the electronic device 100 (hereinafter referred to as the "comparison example") shown in Figure 3.

[0024] Although Figure 3 does not show a cross section, hatching is used to make it easier to understand the temperature distribution resulting from the thermal analysis, and areas with greater temperature increases as a result of the thermal analysis are shown with hatching that is closer to black.

[0025] 3, the comparative example differs from the example in that a heat-generating component 5 is mounted on the upper surface 3a of the substrate 3, and a recessed portion 111 is formed in a region of the lower housing 110 located directly below the terminal 4. In the comparative example, a heat dissipation material 7 is disposed in a region of the lower surface 3b of the substrate 3 located directly below the region where the heat-generating component 5 is mounted, and the gap between this region and the lower housing 110 is filled with the heat dissipation material 7. In the comparative example, the gap between the lower surface 3b of the substrate 3 and a protrusion 112 of the lower housing 110 adjacent to the recessed portion 111, i.e., the thickness of the heat dissipation material 7, is 1 mm. In the comparative example, a current path is formed on the upper surface 3a of the substrate 3 through the terminal 4, the upper surface wiring 331, and the heat-generating component 5, and heat generated in this current path is transferred to the lower housing 8 via the substrate 3 and the heat dissipation material 7.

[0026] In the comparative example and the example, through holes 31 and conductive films 32 are formed on both sides of the heat-generating member 5 in the substrate 3, and press-fit connectors are inserted into these as terminals 4. In the comparative example and the example, the thickness of the substrate 3 is the same, 1.6 mm or more. In the comparative example and the example, a plurality of through electrodes 34 that connect the wirings 331 to 333 are formed on the substrate 3. In the comparative example and the example, the lower housings 8 and 110 are made of aluminum, the heat-dissipating material 7 is a heat-dissipating gel, and the heat-generating member 5 is a power MOSFET.

[0027] In the example, for example, the gap between the region of the underside 3b where the heat-generating component 5 is mounted and the lower housing 8 is 1.4 mm, and the gap between the heat-generating component 5 and the lower housing 8 is 0.5 mm. In the example, a current path is provided on the underside 3b of the substrate 3 through the terminals 4, the underside wiring 333, and the heat-generating component 5, and heat generated in the current path is transferred to the lower housing 8 via the heat dissipation material 7. Note that the above example is an example of a sealing structure in which the surface of the heat-generating component 5 opposite the substrate 3 is completely covered with the sealing resin 54, ensuring insulation. For example, in the case of a sealing structure in which a portion of the surface of the heat-generating component 5 opposite the substrate 3 is exposed from the sealing resin 54, the gap between the heat-generating component 5 and the lower housing 8 is 1 mm in the example.

[0028] For the comparative example and the example, the temperature distribution was analyzed when the heat-generating member 5 was driven under the same conditions using known thermal analysis simulation software. The conditions for the thermal analysis were as follows.

[0029] <Conditions for thermal analysis> Wiring: Length L from terminal 4 to heat generating component 5 is 20 mm, width W is 5 mm Current value: Heat generating element 5 driving current is 1A As a result of the thermal analysis, in the comparative example, the temperature of the vicinity of terminal 4 of upper surface wiring 331 rose by 8.6°C, and the temperature of heat-generating component 5 rose by 3.1°C when a current was applied. On the other hand, in the example, the temperature of the vicinity of terminal 4 of lower surface wiring 333 rose by 6.7°C, and the temperature of heat-generating component 5 rose by 1.4°C when a current was applied, and the temperature rise of the wiring and heat-generating component 5 was suppressed more than in the comparative example. This is thought to be because in the example, heat-generating component 5 is disposed on lower surface 3b, and the distance between heat-generating component 5 and lower housing 8, which is a heat dissipation component, is shorter than in the comparative example, and the structure makes it easier for heat from heat-generating component 5 to dissipate to lower housing 8 without passing through substrate 3.

[0030] According to this embodiment, the terminals are inserted into the through holes 31 of the substrate 3 from the upper surface 3a side, the heat-generating member 5 is mounted on the lower surface 3b, and the heat-generating member 5 is thermally connected to the lower housing 8 facing the lower surface 3b via the heat dissipation member 7. Therefore, in the electronic device 1, the distance between the heat-generating member 5 and the heat dissipation member is shorter than in the comparative example in which the heat-generating member 5 is mounted on the upper surface 3a, and heat dissipation performance is improved. Furthermore, in this electronic device 1, by mounting the heat-generating member 5 on the lower surface 3b, a gap at least equal to the height of the heat-generating member 5 is secured between the lower surface 3b and the lower housing 8. Therefore, in the electronic device 1, contact between the protruding portions 41 of the terminals 4 protruding from the lower surface 3b and the lower housing 8 is suppressed without requiring the lower housing 8 to be recessed to prevent contact with the terminals 4.

[0031] (Modification of the first embodiment) 4, the electronic device 1 may have a structure in which the heat-generating member 5 is in contact with the lower housing 8 when the surface of the heat-generating member 5 opposite the substrate 3 is completely covered with sealing resin 54 to ensure insulation. In this case, the electronic device 1 may not have a heat-dissipating member 7, or the heat-dissipating member 7 may be disposed in an area of ​​the lower surface 3b of the substrate 3 different from the area where the heat-generating member 5 is mounted.

[0032] This modification also provides the electronic device 1 with the same effects as those of the first embodiment.

[0033] (Second embodiment) An electronic device 1 according to the second embodiment will be described.

[0034] 5, the electronic device 1 of this embodiment differs from the first embodiment in that, in addition to the heat-generating member 5, a bus bar 9 is mounted on the lower surface 3b of the substrate 3. This difference will be mainly described in this embodiment.

[0035] The bus bar 9 is made of a conductive material such as metal and is a generally plate-shaped member that reduces the wiring resistance of the underside wiring 333. The bus bar 9 is connected to the underside wiring 333 via a bonding material 91 made of a conductive bonding material such as solder, and serves as a current path on the underside 3b. The bus bar 9 is covered with a heat dissipation material 7, for example, and is thermally connected to the lower housing 8 via the heat dissipation material 7 while being electrically insulated from the lower housing 8. As a result, the electronic device 1 of this embodiment is configured such that the amount of heat generated on the underside 3b is suppressed by the reduction in wiring resistance due to the bus bar 9, and a heat dissipation path is provided in which heat generated on the underside 3b is transferred to the lower housing 8 via the bus bar 9 and the heat dissipation material 7.

[0036] According to this embodiment, in addition to the same effects as those of the first embodiment, the electronic device 1 has an advantage that the number of heat dissipation paths to the lower housing 8 is increased by having the bus bar 9, thereby further improving heat dissipation.

[0037] (Third embodiment) An electronic device 1 according to a third embodiment will be described. In Figures 7 and 9, the outline of a protruding portion 41 of a terminal 4 covered by a terminal cover 10 (described later) is indicated by a broken line when viewed from the lower surface 3b side.

[0038] 6, the electronic device 1 of this embodiment differs from the first embodiment in that it further includes a terminal cover 10 that covers the periphery of the portion of the terminal 4 that protrudes from the lower surface 3b. In this embodiment, this difference will be mainly described.

[0039] As shown in FIGS. 6 and 7 , the terminal cover 10 is a member that surrounds the through-holes 31 and the protruding portions 41 of the terminals 4 inserted therein. Hereinafter, for ease of explanation, the through-holes 31 into which the terminals 4 are inserted may be referred to as "terminal through-holes." When viewed from a direction normal to the bottom surface 3b, the terminal cover 10 has a bottomed, cylindrical shape with a base 10a that surrounds one or more terminal through-holes across a gap and a lid 10b that closes the end of the base 10a opposite the board 3. The terminal cover 10 is made of, for example, a conductive metal material or its alloy material with high thermal conductivity and is thermally connected to the lower housing 8 by a heat sink 7. This allows the terminal cover 10 to more easily transfer heat near the terminals 4 to the lower housing 8 and prevents electromagnetic noise from entering the terminals 4 from other locations. Furthermore, the terminal cover 10 prevents the heat dissipation material 7 from entering the terminal through-holes, and thus prevents poor contact between the terminals 4 and the conductive film 32 caused by the heat dissipation material 7 .

[0040] The terminal cover 10 may be a bottomless cylinder having only a base 10a, as shown in Fig. 8. Alternatively, the terminal covers 10 may be attached to the terminal through-holes one by one, covering the terminal through-holes individually, as shown in Fig. 9. In this case, the terminal covers 10 have, for example, wall portions 10c arranged on both sides of the terminal through-holes and the protruding portions 41 of the terminals 4, and lid portions 10b connecting the tips of the wall portions 10c and covering the protruding portions 41, and are attached side by side with their orientations aligned.

[0041] According to this embodiment, in addition to the same effects as those of the first embodiment, the electronic device 1 has the effect of increasing the number of heat dissipation paths to the lower housing 8 by having the terminal cover 10, thereby further improving heat dissipation. Furthermore, if the terminal cover 10 of this electronic device 1 is made of a conductive material, the inflow of electromagnetic noise from other parts to the terminals 4 is suppressed, thereby improving reliability.

[0042] (Fourth embodiment) An electronic device 1 according to a fourth embodiment will be described.

[0043] 10, the electronic device 1 of this embodiment differs from the first embodiment in that it further includes a conductive tube 11 that is inserted into a through hole 31. This difference will be mainly described in this embodiment.

[0044] The conductive tube 11 has, for example, a bottomless cylindrical tube portion 11a and an annular flange 11b provided at one end of the tube portion 11a, with the extension direction along the axis of the tube portion 11a. The conductive tube 11 is made of any conductive material, for example, copper, and is press-fit into the through-hole 31 to electrically connect to the conductive film 32. For example, the inner diameter of the tube portion 11a is equal to or smaller than the outer diameter of the terminal 4, and the conductive tube 11 serves to hold the inserted terminal 4 and improve the connection strength with the terminal 4. For example, the tube portion 11a of the conductive tube 11 is inserted from the bottom surface 3b, and the flange 11b connects to the bottom surface wiring 333 on the bottom surface 3b, thereby reducing the electrical resistance and thermal resistance of the bottom surface wiring 333. The conductive tube 11 also serves to reduce the electrical resistance and thermal resistance in the thickness direction of the substrate 3 by using the tube portion 11a. The conductive tube 11 may also be referred to as a busbar collar. When the conductive cylinder 11 is a cylinder with no bottom, the heat dissipation material 7 is arranged so as not to enter the conductive cylinder 11 and not to come into contact with the conductive cylinder 11, for example.

[0045] According to this embodiment, in addition to the same effects as those of the first embodiment, the electronic device 1 has the conductive tube 11, which reduces the electrical resistance and thermal resistance in the thickness direction of the substrate 3 and also improves the connection strength with the terminal 4. Furthermore, when the conductive tube 11 has the flange 11b, the electronic device 1 is electrically connected to the upper surface wiring 331 or the lower surface wiring 333, thereby achieving the effect of reducing wiring resistance.

[0046] (First modified example of the fourth embodiment) 11, the conductive tube 11 may have a flange 11b formed at a position away from the end of the tube portion 11a in the extension direction, and a lid portion 11c that closes the end. When the lid portion 11c is provided, the heat dissipation material 7 is arranged to cover the lid portion 11c of the conductive tube 11, thermally connecting the conductive tube 11 and the lower housing 8. This provides the electronic device 1 with a heat dissipation path to the lower housing 8 via the conductive tube 11 and the heat dissipation material 7, further improving heat dissipation.

[0047] According to this modified example, in addition to the same effects as those of the above-mentioned fourth embodiment, the conductive tube 11 is thermally connected to the lower housing 8 via the heat dissipation material 7, resulting in an electronic device 1 which also has the effect of further improving the heat dissipation properties of the terminals 4.

[0048] (Second modified example of the fourth embodiment) For example, as shown in FIG. 12, the conductive cylinder 11 may have a cylindrical shape with a bottom, a cylinder portion 11a having a lid portion 11c, and no flange 11b.

[0049] This modification also provides the electronic device 1 with the same effects as the first modification.

[0050] (Third modified example of the fourth embodiment) 13, the conductive tube 11 may have a cylindrical shape with a bottom, a tube portion 11a having a lid portion 11c, and a flange 11b formed on the opening side of the tube portion 11a opposite to the lid portion 11c. In this case, the conductive tube 11 is inserted into the through hole 31 from the top surface 3a side, and the flange 11b is electrically connected to the top surface wiring 331.

[0051] This modification also provides the electronic device 1 with the same effects as the first modification.

[0052] (Fourth Modification of the Fourth Embodiment) 14, the conductive tube 11 may have a cylindrical portion 11a that is elliptical when viewed in the extension direction, and may have a protrusion 11d that extends from a portion of the cylindrical portion 11a that has a smaller outer diameter. The protrusion 11d extends, for example, in a radial direction with the extension direction as its axis, and serves to press-fit and hold the conductive tube 11 when inserted into the through-hole 31. Since the cylindrical portion 11a of the conductive tube 11 is elliptical, when a press-fit terminal is used as the terminal 4, the terminal 4 is positioned in the direction of the cylindrical portion 11a that has a larger inner diameter, which prevents the terminal 4 from rotating and prevents poor fitting with the terminal 4.

[0053] According to this modified example, in addition to the effects of the above-described fourth embodiment, the electronic device 1 has an elliptical cylindrical shape in the cylindrical portion 11a of the conductive cylinder 11, which positions the terminal 4, thereby preventing rotation of the terminal 4 and resulting poor contact.

[0054] (Fifth Modification of the Fourth Embodiment) 15, the conductive tube 11 may have a cylindrical portion 11a that is substantially circular when viewed in the extension direction, and may have a slit portion 11e on the inner wall surface that can fit with the terminal 4. Even in this case, when a press-fit terminal is used as the terminal 4, the conductive tube 11 positions the terminal 4 in the slit portion 11e, thereby suppressing rotation of the terminal 4 and preventing poor fitting.

[0055] This modification also provides the electronic device 1 with the same effects as the fourth modification.

[0056] (Sixth Modification of the Fourth Embodiment) 16, the inner wall surface of the cylindrical portion 11a of the conductive tube 11 may be welded to the terminal 4. For example, with the terminal 4 inserted into the cylindrical portion 11a of the conductive tube 11, a pair of electrodes (not shown) may be connected to the terminal 4 and the conductive tube 11, respectively, and a current of a predetermined level or higher may be applied to weld the terminal 4 and the conductive tube 11. This improves the bonding strength between the terminal 4 and the conductive tube 11, reduces the contact resistance between the terminal 4 and the conductive tube 11, and ultimately reduces impedance, thereby improving the reliability of the electronic device 1. Note that the welding between the terminal 4 and the conductive tube 11 may be performed before or after inserting the conductive tube 11 into the through-hole 31.

[0057] According to this modification, in addition to the effects of the fourth embodiment, the electronic device 1 can also obtain the effect of further improving reliability by welding the terminal 4 and the conductive tube 11 together, thereby reducing the contact resistance and impedance between them.

[0058] In addition, the electronic device 1 according to this embodiment and its modified examples may be freely combined or used in conjunction with the above-mentioned configuration of the conductive tube 11 and the fitting or welding with the terminal 4, except in cases where they are clearly incompatible.

[0059] (Fifth embodiment) An electronic device 1 according to the fifth embodiment will be described.

[0060] 17, the electronic device 1 of this embodiment differs from the first embodiment in that it further includes filler members 12 attached to through holes 31 of the substrate 3 that do not have terminals 4 inserted therein. This difference will be mainly described in this embodiment.

[0061] The filler 12 is made of any conductive material, such as copper, and is attached to the through-holes 31 other than the terminal through-holes to fill the through-holes 31. As shown in FIGS. 17 and 18 , the filler 12 has a cylindrical base 12a and an annular flange 12b extending from the axial end of the base 12a. The filler 12 abuts and electrically connects to the conductive film 32, forming one of the current paths of the electronic device 1 and reducing the electrical resistance and thermal resistance in the thickness direction of the substrate 3. The filler 12 is inserted into the through-hole 31 from the bottom surface 3b, for example, and the flange 12b is connected to the bottom wiring 333. The filler 12 may also be referred to as a collar. The filler 12 is thermally connected to the lower housing 8, for example, via a heat dissipation material 7, forming one of the heat dissipation paths.

[0062] According to this embodiment, in addition to the same effects as those of the first embodiment, the electronic device 1 has the effect of reducing the electrical resistance and thermal resistance in the thickness direction of the substrate 3 due to the inclusion of the filler member 12. Furthermore, in the electronic device 1, the filler member 12 is thermally connected to the lower housing 8 via the heat dissipation material 7, so that the number of heat dissipation paths for the substrate 3 is increased, thereby improving heat dissipation.

[0063] (Sixth embodiment) An electronic device 1 according to a sixth embodiment will be described.

[0064] 19, the electronic device 1 of this embodiment differs from the first embodiment in that it further includes an insulating spacer 13 that thermally connects a member, different from the heat-generating member 5, among the members mounted on the lower surface 3b side of the substrate 3 to the lower housing 8. In this embodiment, this difference will be mainly described.

[0065] 19 , for example, the electronic device 1 has a bus bar 9 attached to the lower surface 3b of the substrate 3, and an insulating spacer 13 disposed between the bus bar 9 and the lower housing 8. The insulating spacer 13 is made of any electrically insulating material and is a component that abuts against both the bus bar 9 and the lower housing 8 to thermally connect them and serve as a heat dissipation path. By appropriately adjusting the thickness of the insulating spacer 13, it is possible to prevent direct contact between the heat-generating component 5 and the lower housing 8 while ensuring that the gap between them is equal to or smaller than a predetermined value. In other words, the insulating spacer 13 not only constitutes a heat dissipation path itself, but also serves to increase thermal conductivity between the heat-generating component 5 and the lower housing 8, thereby further improving heat dissipation.

[0066] According to this embodiment, in addition to the features of the second embodiment, the electronic device 1 has the insulating spacer 13, which allows heat from components other than the heat-generating component 5 mounted on the lower surface 3b to efficiently dissipate to the lower housing 8, thereby improving heat dissipation. Furthermore, the insulating spacer 13 in the electronic device 1 keeps the gap between the heat-generating component 5 and the lower housing 8 at a predetermined value or less, thereby increasing thermal conductivity while ensuring insulation between them, and thereby further improving the heat dissipation of the heat-generating component 5. Furthermore, the electronic device 1 has a structure in which the heat-generating component 5 and the lower housing 8 are reliably prevented from coming into contact with each other, which, in the case of an in-vehicle application, suppresses transmission of vehicle vibrations to the heat-generating component 5, thereby improving reliability by suppressing element damage caused by vibrations.

[0067] (First modified example of the sixth embodiment) When the electronic device 1 has a terminal cover 10 instead of the bus bar 9 as shown in FIG. 20, for example, an insulating spacer 13 is disposed between the terminal cover 10 and the lower housing 8.

[0068] This modification also provides the electronic device 1 with the same effects as those of the sixth embodiment.

[0069] (Second modified example of the sixth embodiment) 21, the electronic device 1 may have a conductive spacer 14 instead of the insulating spacer 13. In this case, the substrate 3 has, for example, a connection portion 35 on the lower surface 3b, which is a conductive pattern electrically insulated from the lower surface wiring 333, and the conductive spacer 14 is connected to the connection portion 35. The conductive spacer 14 is made of any conductive material, such as copper, and thermally connects the connection portion 35 and the lower housing 8. By appropriately adjusting the thickness of the conductive spacer 14, as in the case of the insulating spacer 13, the conductive spacer 14 serves to prevent direct contact between the heat-generating member 5 and the lower housing 8 while keeping the gap therebetween at a predetermined value or less.

[0070] This modification also provides the electronic device 1 with the same effects as those of the sixth embodiment.

[0071] (Other embodiments) Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one, or less than one, are also within the scope and spirit of the present disclosure.

[0072] In the above-described embodiments and their modified examples, a power semiconductor module is given as a representative example of the heat-generating member 5, but the present invention is not limited to this. For example, components that are mounted on the lower surface 3b of the substrate 3 or that are located on the lower surface 3b side and that are electrically connected, such as the bus bar 9, the terminal cover 10, the conductive tube 11, the filling member 12, and the protruding portion 41 of the terminal 4, can also be considered heat-generating members. Therefore, unless clearly incompatible, heat-generating members other than the power semiconductor module, such as the bus bar 9, can be considered as the heat-generating member 5, and the structures of the above-described embodiments and their modified examples can be applied to the extent possible.

[0073] Furthermore, in each of the above embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are particularly explicitly stated as essential or are clearly considered essential in principle. Furthermore, in each of the above embodiments, when the numbers, values, amounts, ranges, etc. of the components of the embodiments are mentioned, they are not limited to the specific numbers unless they are particularly explicitly stated as essential or are clearly limited to a specific number in principle. Furthermore, in each of the above embodiments, when the shapes, positional relationships, etc. of the components are mentioned, they are not limited to the shapes, positional relationships, etc. unless they are particularly explicitly stated or are clearly limited to a specific shape, positional relationship, etc. in principle.

[0074] (Aspects of the present disclosure) The present disclosure described above can be understood from the following viewpoints, for example.

[0075] [First viewpoint] a substrate (3) having an upper surface (3a) and a lower surface (3b) that are opposite surfaces, a through hole (31) connecting the upper surface and the lower surface, and a conductive film (32) covering the wall surface of the through hole; A terminal (4) inserted into the through hole from the top surface side; a heat generating member (5, 9, 10, 11, 12, 41) mounted on the lower surface; and a heat dissipation member (8) disposed opposite the lower surface, having higher thermal conductivity than the substrate, and thermally connected to the heat-generating member. [Second perspective] The electronic device according to the first aspect, further comprising an insulating heat dissipation material (7) connecting the heat generating member and the heat dissipation member. [Third Perspective] The electronic device according to a first aspect, wherein the heat generating member has a surface opposite to the substrate covered with an insulating resin and is in contact with the heat dissipation member. [Fourth viewpoint] The electronic device according to the first or second aspect, wherein the heat-generating component is a semiconductor package having a power semiconductor element (52), a conductive clip (53) connected to the power semiconductor element, and an insulating sealing resin (54) covering the power semiconductor element, and the side opposite to the substrate is completely covered with the sealing resin. [Fifth viewpoint] Further, a plate-shaped bus bar (9) is connected to the lower surface, The electronic device according to a second aspect, wherein the bus bar is thermally connected to the heat dissipation member via the heat dissipation material. [Sixth viewpoint] The terminal cover (10) is connected to the lower surface near the through hole, surrounds the portion of the terminal that protrudes beyond the lower surface, and is made of a material with higher thermal conductivity than the board. The electronic device according to a second aspect, wherein the terminal cover is thermally connected to the heat dissipation member via the heat dissipation material. [Seventh viewpoint] The device further includes a cylindrical conductive tube (11) made of a conductive material, inserted into the through hole, and in contact with the conductive film, The electronic device according to any one of the first to sixth aspects, wherein the terminal is press-fitted and held in the conductive tube. [Eighth viewpoint] The heat-generating member and the heat-dissipating member are connected together, and the heat-dissipating member has higher thermal conductivity than the substrate and is also electrically insulating. The electronic device according to a seventh aspect, wherein the conductive tube has a closed end protruding from the lower surface and is thermally connected to the heat dissipation member via the heat dissipation material. [Ninth viewpoint] The electronic device according to the seventh or eighth aspect, wherein the conductive cylinder has an elliptical cylindrical portion into which the terminal is inserted. [10th viewpoint] The electronic device according to a seventh or eighth aspect, wherein the conductive cylinder has a slit portion (11e) on an inner wall surface into which the terminal is inserted. [11th viewpoint] The electronic device according to any one of the seventh to tenth aspects, wherein the terminal is welded to the conductive tube. [12th viewpoint] the substrate has a plurality of the through holes and the conductive films; The connector further includes a filler member (12) that is inserted into any of the through holes other than the through hole into which the terminal is inserted, the filler member (12) being made of a metal material and filling the other through holes, The electronic device according to a second aspect, wherein the filling member is thermally connected to the heat dissipation member via the heat dissipation material. [13th viewpoint] The substrate has components (9, 10) mounted on the lower surface thereof that are different from the heat-generating component, The electronic device according to any one of the first, second, fourth to twelfth aspects, further comprising an insulating spacer (13) connecting the different components and the heat dissipation member. [14th viewpoint] The heat dissipation member further includes a conductive spacer (14) that connects the lower surface of the substrate and the heat dissipation member, The electronic device according to any one of the first, second, fourth to twelfth aspects, wherein the conductive spacer is connected to a connection portion (35) on the lower surface that is electrically insulated from at least the wiring connected to the heat-generating component. [Explanation of symbols]

[0076] 3...substrate, 3a...upper surface, 3b...lower surface, 31...through hole, 32...conductive film, 35...connection portion, 4...terminal, 5...heat-generating member, 52...semiconductor element, 53...conductive clip, 54...sealing resin, 7...heat dissipation material, 8...lower housing (heat dissipation member), 9...bus bar, 10...terminal cover, 11...conductive tube, 11e...slit portion, 12...filler member, 13...insulating spacer, 14...conductive spacer

Claims

1. a substrate (3) having an upper surface (3a) and a lower surface (3b) that are opposite surfaces, a through hole (31) connecting the upper surface and the lower surface, and a conductive film (32) covering the wall surface of the through hole; A terminal (4) inserted into the through hole from the top surface side; a heat generating member (5, 9, 10, 11, 12, 41) mounted on the lower surface; and a heat dissipation member (8) disposed opposite the lower surface, having higher thermal conductivity than the substrate, and thermally connected to the heat-generating member.

2. The electronic device according to claim 1, further comprising an insulating heat dissipation material (7) connecting the heat generating member and the heat dissipation member.

3. The electronic device according to claim 1 , wherein the heat generating member has a surface opposite to the substrate covered with an insulating resin and in contact with the heat dissipation member.

4. 2. The electronic device according to claim 1, wherein the heat-generating component is a semiconductor package having a power semiconductor element (52), a conductive clip (53) connected to the power semiconductor element, and an insulating sealing resin (54) covering the power semiconductor element, the side opposite to the substrate being completely covered with the sealing resin.

5. Further, a plate-shaped bus bar (9) is connected to the lower surface, The electronic device according to claim 2 , wherein the bus bar is thermally connected to the heat dissipation member via the heat dissipation material.

6. The terminal cover (10) is connected to the lower surface near the through hole, surrounds the portion of the terminal that protrudes beyond the lower surface, and is made of a material with higher thermal conductivity than the substrate. The electronic device according to claim 2 , wherein the terminal cover is thermally connected to the heat dissipation member via the heat dissipation material.

7. The device further includes a cylindrical conductive tube (11) made of a conductive material, inserted into the through hole, and in contact with the conductive film; The electronic device according to claim 1 , wherein the terminal is press-fitted and held in the conductive tube.

8. The heat-generating member and the heat-dissipating member are connected together, and the heat-dissipating member has higher thermal conductivity than the substrate and is also electrically insulating. The electronic device according to claim 7 , wherein the conductive tube has a closed end protruding from the lower surface and is thermally connected to the heat dissipation member via the heat dissipation material.

9. The electronic device according to claim 7 , wherein the conductive cylinder has an elliptical cylindrical portion into which the terminal is inserted.

10. 8. The electronic device according to claim 7, wherein the conductive cylinder has a slit (11e) on an inner wall surface into which the terminal is inserted.

11. The electronic device according to claim 7 , wherein the terminal is welded to the conductive tube.

12. the substrate has a plurality of the through holes and the conductive films; The connector further includes a filler member (12) that is inserted into any of the through holes other than the through hole into which the terminal is inserted, the filler member being made of a metal material and filling the other through holes, The electronic device according to claim 2 , wherein the filling member is thermally connected to the heat dissipation member via the heat dissipation material.

13. The substrate has components (9, 10) mounted on the lower surface thereof that are different from the heat-generating component, 13. The electronic device according to claim 1, further comprising an insulating spacer (13) connecting the different components and the heat dissipation member.

14. The heat dissipation member further includes a conductive spacer (14) that connects the lower surface of the substrate and the heat dissipation member, 13. The electronic device according to claim 1, wherein the conductive spacer is connected to a connection portion (35) on the lower surface that is electrically insulated from at least the wiring connected to the heat-generating component.

Images