Semiconductor module

Abstract

In semiconductor modules, this prevents corrosive gases from entering through the gap between the lid that seals the space housing the semiconductor element and the terminals. [Solution] The semiconductor module (1) comprises a semiconductor element (50), a wiring board (60) on which the semiconductor element (50) is mounted, a frame-shaped case (20) housing the semiconductor element (50) and the wiring board (60), terminals (11-13) electrically connected to the wiring board (60), a lid (30) having a lid through-hole (31) into which the terminals (11-13) are inserted and which closes the housing space (S) of the semiconductor element (50) and the wiring board (60), an inner cover (70) having an inner through-hole (71) into which the terminals (11-13) are inserted and which is disposed in the housing space (S), and a sealing material (A) that seals the space between the lid (30) and the inner cover (70) around the terminals (11-13).

Description

Technical Field

[0001] The present invention relates to a semiconductor module including a case for housing a semiconductor element and a wiring board.

Background Art

[0002] Conventionally, as a semiconductor module used in a power conversion device or the like, a semiconductor module including a case for housing a semiconductor element and a wiring board is known (see, for example, Patent Documents 1 to 3). In this type of semiconductor module, terminals such as main terminals and auxiliary terminals are insert-molded with the case, and a lid for closing the accommodation space of the semiconductor element and the wiring board is arranged, or the case is arranged such that the terminals are inserted into through-holes of the case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a configuration in which a case or a lid is put on after the terminals are connected to the substrate, the terminals are inserted into through-holes of the lid and the tip portions are bent. Therefore, a gap is generated between the terminals and the through-holes of the lid. In particular, when the tip portions of the terminals are bent, a sealing material cannot be supplied to the gap on the back side of the bent portion of the terminals. If the gap cannot be closed in this way, corrosive gases (such as hydrogen sulfide and sulfuric acid gas) flow in.

[0005] In one aspect, an object of the present invention is to provide a semiconductor module that can prevent corrosive gases from entering through the gap between the lid that seals the housing space of the semiconductor element and the terminals. [Means for solving the problem]

[0006] In one embodiment, the semiconductor module comprises a semiconductor element, a wiring board on which the semiconductor element is mounted, a frame-shaped case housing the semiconductor element and the wiring board, terminals electrically connected to the wiring board, a lid having a through-hole into which the terminals are inserted and closing the housing space for the semiconductor element and the wiring board, an inner cover having an inner through-hole into which the terminals are inserted and disposed in the housing space, and a sealing material sealing the space between the lid and the inner cover around the terminals. [Effects of the Invention]

[0007] According to the above embodiment, it is possible to prevent corrosive gases from entering through the gap between the lid that seals the housing space of the semiconductor element and the terminals. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing a semiconductor module according to one embodiment. [Figure 2] This is a plan view showing a semiconductor module according to one embodiment. [Figure 3] This is a plan view showing a heat dissipation base, a semiconductor element, and a wiring board in one embodiment. [Figure 4] This is a circuit diagram of a semiconductor module in one embodiment. [Figure 5] This is a plan view showing a case in which the main terminal and auxiliary terminal are insert-molded according to one embodiment. [Figure 6] This is a plan view showing an inner cover, case, etc., in one embodiment. [Figure 7] This is a cross-sectional view taken along line VII-VII in Figure 6. [Figure 8]This is a plan view showing an inner cover, case, etc., in a modified example of one embodiment. [Figure 9] This is a plan view showing a case in another embodiment where the main terminal and auxiliary terminal are insert-molded. [Figure 10] This is a cross-sectional view of XX in Figure 9. [Figure 11] This is a perspective view showing a semiconductor module in a comparative example. [Figure 12] This is a plan view showing a semiconductor module in a comparative example. [Modes for carrying out the invention]

[0009] Hereinafter, a semiconductor module 1 according to one embodiment and another embodiment of the present invention will be described in detail with reference to the drawings. The X, Y, and Z axes in each of the referenced figures are shown for the purpose of defining the directions and surfaces of the example semiconductor module 1, etc. The X, Y, and Z axes are orthogonal to each other and form a right-handed system. In the following description, the Z direction may be referred to as the up and down direction. Also, the surface containing the X and Y axes may be referred to as the top surface or bottom surface. These directions and surfaces are terms used for convenience of explanation, and the correspondence with the X, Y, and Z directions may change depending on the mounting orientation of the semiconductor module 1, etc. For example, in this specification, the surface facing the positive Z direction (+Z direction) of the components constituting the semiconductor module 1 is referred to as the top surface, and the surface facing the negative Z direction (-Z direction) is referred to as the bottom surface. However, the surface facing the negative Z direction may be referred to as the top surface, and the surface facing the positive Z direction may be referred to as the bottom surface. Furthermore, in this specification, a plan view means a perspective view of the top surface (XY plane) of the semiconductor module 1, etc., from the positive Z-direction to the negative Z-direction.

[0010] The aspect ratios and relative sizes of components in each diagram are purely schematic representations and do not necessarily correspond to the actual relationships in manufactured semiconductor modules. For explanatory purposes, the relative sizes of components may be exaggerated in some cases. Furthermore, the shape of the same component may differ between different diagrams.

[0011] In the following description, as an example of the semiconductor module 1 according to one embodiment and other embodiments, an apparatus applied to a power conversion apparatus such as an inverter device of an industrial or in-vehicle motor will be given. For this reason, in the following description, detailed descriptions of the same or similar configurations, functions, operations, assembly methods, etc. as those of known semiconductor modules will be omitted.

[0012] FIG. 1 is a perspective view showing the semiconductor module 1. FIG. 2 is a plan view showing the semiconductor module 1.

[0013] The semiconductor module 1 shown in FIGS. 1 and 2 includes main terminals 11 to 13, auxiliary terminals 14 to 17, a case 20, a lid 30, a heat dissipation base 40 (see FIGS. 1 and 3), a plurality of semiconductor elements 50 (see FIG. 3), a plurality of wiring boards 60 (see FIG. 3), and an inner cover 70 (see FIGS. 6 and 7).

[0014] As shown in FIG. 5, the main terminals 11 to 13 and the auxiliary terminals 14 to 17 are insert-molded in the case 20. Each of the main terminals 11 to 13 and the auxiliary terminals 14 to 17 is electrically connected to the wiring board 60 by being joined to terminal joints j1 to j8 such as solder of the wiring board 60 (first conductor layer 61) shown in FIG. 3 described later.

[0015] The main terminals 11 to 13 are input terminals and output terminals of the semiconductor module 1, and a main current flows therethrough. As also shown in FIG. 4, for example, the main terminal 11 is a C1 terminal, the main terminal 12 is an E2 terminal, and the main terminal 13 is a C2E1 terminal. As shown in FIGS. 3 and 5, the main terminal 11 is joined to the terminal joint j1 of the first conductor layer 61, the main terminal 12 is joined to the terminal joint j2 of the first conductor layer 61, and the main terminal 13 is joined to the terminal joints j3 and j4 of the first conductor layer 61.

[0016] As shown in Figures 1 and 2, each of the main terminals 11 to 13 is a plate-shaped metal member that is bent at the tip portion protruding from the cover 30. For example, the tip portions of main terminals 11 and 12 are bent to the negative side in the Y direction, and the tip portion of main terminal 13 is bent to the positive side in the Y direction. The main terminals 11 to 13 have main terminal through holes 11a, 12a, and 13a in the bent tip portions. Screws for the external terminal side (not shown) are inserted into these main terminal through holes 11a, 12a, and 13a.

[0017] Each of the auxiliary terminals 14 to 17 is electrically connected to the wiring board 60 (first conductor layer 61) by being joined to terminal joints j5 to j8 such as solder on the wiring board 60 as shown in Figure 3. They are plate-shaped metal members that penetrate the case 20 and protrude to the outside of the case 20 in a single protruding direction (positive Z direction). The auxiliary terminals 14 to 17 are terminals through which the main current does not flow, such as control terminals. As shown in Figure 4, for example, auxiliary terminal 14 is the G1 terminal, auxiliary terminal 15 is the E1 terminal, auxiliary terminal 16 is the E2 terminal, and auxiliary terminal 17 is the G2 terminal. The auxiliary terminals 14 to 17 penetrate the case 20 in a region different from the housing space S of the semiconductor element 50 and the wiring board 60 in the case 20.

[0018] The case 20 is formed using a thermoplastic resin material such as PPS (Poly Phenylene Sulfide) or PA (Poly Amide), and is insulating. As shown in Figure 5, the case 20 has a main body portion 21, a terminal holding portion 22, and a beam portion 23, and houses the semiconductor element 50 and the wiring board 60 shown in Figures 3 and 7.

[0019] As shown in Figure 7, the case 20 is fixed, for example, to the periphery of the upper surface of the heat dissipation base 40 by adhesive on the lower surface of the main body 21. As shown in Figure 1, fastening holes 21a are provided at the four corners of the case 20 (main body 21) in a plan view for fixing the case 20 together with the heat dissipation base 40 to a cooler (not shown). Also, as shown in Figure 5, the main body 21 of the case 20 has a frame shape that is located around the housing space S for the semiconductor element 50 and the wiring board 60. The case 20 as a whole has a frame shape due to having the main body 21.

[0020] As shown in Figures 5 and 7, the terminal holding portion 22 holds the insert-molded main terminals 11 to 13.

[0021] The beam section 23 connects the main body section 21 and the terminal holding section 22. For example, as shown in Figure 5, the beam section 23 includes two beam sections 23 extending in the Y direction and four beam sections 23 extending in the X direction that connect these two beam sections 23 to the main body section 21 within the housing space S surrounded by the main body section 21. Terminal holding sections 22 are provided on three of the four beam sections 23 extending in the X direction.

[0022] As shown in Figure 1, the lid 30 has three lid through holes 31 into which the main terminals 11 to 13 are inserted, and closes the upper part (positive side in the Z direction) of the housing space S for the semiconductor element 50 and the wiring board 60 in the case 20.

[0023] The lid 30 has three nut housing sections 32. Each of these three nut housing sections 32 is provided to protrude from the lid 30 toward the positive Z direction, and a nut N is positioned therein. This nut N is located below the main terminal through holes 11a to 13a of the main terminals 11 to 13 which are bent as described above. The nut housing section 32 is provided with the lid through hole 31 described above.

[0024] The lid 30 is preferably bonded to the main body 21 of the case 20 with adhesive A as shown in Figure 7, in a support recess 21b provided in the main body 21 of the case 20 so as to surround the storage space S, and the periphery of the lid 30 is sealed to the main body 21. This adhesive A can be called a first lid sealant or lid periphery sealant. Alternatively, the support recess 21b may be omitted, and the upper surface of the main body 21 and the lower surface of the periphery of the lid 30 may be sealed with adhesive A.

[0025] The assembly sequence of the semiconductor module 1 is as follows: for example, each terminal 11-17 is prepared by insert molding into the case 20. The prepared terminals 11-17 and the case 20 form an integrated structure, and the case 20 is placed on the wiring board 60 so that it is joined to the terminal joints j1-j8 shown in Figure 3, and each terminal 11-17 is joined to each terminal joint j1-j8. After joining, an inner cover 70, which will be described later, is placed on top of the case 20 so that the main terminals 11-13 are inserted into the inner through-holes 71, as shown in Figure 6. Adhesive A is placed on the inner cover 70. Then, a lid 30 is placed over the case 20 so that the main terminals 11-13 are inserted into the lid through-holes 31. This lid 30 is bonded to the case 20 at the support recess 21b of the case 20 as described above, and is also bonded to the inner cover 70, which will be described later. After that, the tips of the main terminals 11-13 are bent as described above.

[0026] As shown in Figure 3, the heat dissipation base 40 has a rectangular shape in plan view. The heat dissipation base 40 has fastening holes 41 at the four corners in plan view. The heat dissipation base 40 is fastened to a cooler (not shown) together with the case 20 as described above by screws inserted into the fastening holes 41.

[0027] The heat dissipation base 40 is a component that functions as a heat conductive member that conducts the heat generated by the semiconductor element 50 to the cooler, and is formed from a metal plate such as a copper plate or an aluminum plate.

[0028] As shown in Figures 3 and 7, the semiconductor element 50 is mounted on the wiring board 60. The semiconductor element 50 is, for example, an IGBT (Insulated Gate Bipolar Transistor), which is the switching element 50-1 shown in Figure 4, and an FWD (Free Wheeling Diode) element, which is the diode element 50-2. Other semiconductor elements, such as an RC (Reverse Conducting)-IGBT element, which integrates the switching element 50-1 and the diode element 50-2 connected in antiparallel to the switching element 50-1, may also be arranged as the semiconductor element 50. The switching element 50-1 and the diode element 50-2 in the semiconductor element 50 are not limited to a Si substrate, but may be formed on a semiconductor substrate using a wide bandgap semiconductor such as SiC (Silicon Carbide) or GaN (Gallium Nitride). Furthermore, the switching element 50-1 may be composed of, for example, a SiC-MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or a BJT (Bipolar Junction Transistor). Furthermore, the diode element 50-2 may be composed of, for example, a SiC-SBD (Schottky Barrier Diode), a JBS (Junction Barrier Schottky) diode, an MPS (Merged PN Schottky) diode, a PN diode, or the like.

[0029] The semiconductor element 50 is bonded to the first conductor layer 61 of the wiring board 60 and is electrically connected directly or indirectly to other semiconductor elements 50, the first conductor layer 61 of the wiring board 60, the main terminals 11-13, auxiliary terminals 14-17, etc., by wiring W. The wiring W is, for example, a metallic bonding wire. The wiring W may be replaced with other wiring such as leads formed by processing a metal plate such as a copper plate.

[0030] As shown in Figure 7, multiple wiring boards 60 are joined to a common single heat dissipation base 40 at their lower surfaces (second conductor layer 62) by a bonding material such as solder. The wiring board 60 has a rectangular shape in plan view and includes a first conductor layer 61, a second conductor layer 62, and an insulating layer 63. The wiring board 60 may be, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazing) substrate. The wiring board 60 may also be called a laminated substrate, an insulating circuit board, an insulating heat dissipation circuit board, etc.

[0031] The first conductor layer 61 is a component that functions as a wiring member in an inverter circuit, for example, and is provided in multiple separate portions on the upper surface of the insulating layer 63 using a metal plate or metal foil made of copper, aluminum, or the like. The first conductor layer 61 is electrically connected to other first conductor layers 61, semiconductor elements 50, main terminals 11-13, auxiliary terminals 14-17, etc., by wiring W. The first conductor layer 61 may also be called a conductor plate, conductor pattern, conductive layer, wiring pattern, etc.

[0032] The second conductor layer 62 functions as a heat conduction member that conducts heat generated in the inverter circuit to the heat dissipation base 40, and is provided on the lower surface of the insulating layer 63 using a metal plate or metal foil made of copper, aluminum, etc. The second conductor layer 62 (wiring board 60) is joined to the heat dissipation base 40 by a bonding material such as solder. The second conductor layer 62 may also be called a heat dissipation layer, heat sink, heat dissipation pattern, conductor pattern, etc.

[0033] The insulating layer 63 is, for example, a ceramic substrate. The insulating layer 63 is not limited to a specific substrate, but may be a ceramic substrate formed from a ceramic material such as aluminum nitride (AlN), aluminum oxide (Al2O3), silicon nitride (Si3N4), and a composite material of aluminum oxide (Al2O3) and zirconium oxide (ZrO2). The insulating layer 63 may also be, for example, a substrate molded from an insulating resin such as epoxy resin, a substrate impregnated with an insulating resin onto a base material such as glass fiber, or a substrate whose surface is coated with an insulating resin on a flat metal core.

[0034] The shape, number, and location of the main terminals 11-13, auxiliary terminals 14-17, semiconductor elements 50, and wiring boards 60 can be changed as appropriate. While it is desirable to have multiple units of these, the number of semiconductor elements 50 and wiring boards 60 can be any number. Furthermore, as shown in Figure 7, it is preferable that the semiconductor elements 50 and wiring boards 60 be sealed with a sealing material such as sealing gel G or epoxy resin. The sealing gel G is located above the upper end of the beam portion 23, but only below the upper end of the terminal holding portion 22.

[0035] The inner cover 70 shown in Figures 6 and 7 has three inner through holes 71 into which the main terminals 11 to 13 are inserted, and is positioned in the housing space S. The inner cover 70 may be formed in a flat plate shape from, for example, a resin material. The thickness of the inner cover 70 depends on the sealing gel G and the distance in the Z direction between the terminal holding part 22 and the lid 30, but one example is 1.5 mm to 1.8 mm. The inner cover 70 may be supported by the three terminal holding parts 22. The inner cover 70 may simply rest on the terminal holding parts 22, or it may be fixed to the terminal holding parts 22 by adhesive or the like.

[0036] Although the inner cover 70 can be a single inner cover 70, rather than having the same number of inner through-holes 71 as the main terminals 11-13, by having three (or more) inner through-holes 71, as shown in Figure 8 (a modified example of this embodiment), three inner covers 80, the same number as the main terminals 11-13, may also be arranged. In this case, each of the three inner covers 80 will have an inner through-hole 81 and will be supported by the terminal holding portion 22.

[0037] As shown in Figure 7, after the inner cover 70 is placed on the terminal holding portion 22 (case 20), an adhesive A, which is an example of a sealing material, is placed on the upper surface of the inner cover 70. This adhesive A is, for example, silicone-based and is placed in any shape, such as a sheet. This adhesive A can also be called the second lid sealing material.

[0038] Then, when the lid 30 is placed over the case 20, the adhesive A is spread around the main terminals 11-13, sealing the space between the lid 30 and the inner cover 70. In order to seal the space between the lid 30 and the inner cover 70 in this way, the adhesive A should be supplied so as to surround the main terminals 11-13 over their entire circumference (360 degrees in a plan view) and bond to the main terminals 11-13 over their entire circumference.

[0039] Here, the lid 30 is provided with a lid through-hole 31 for inserting the main terminals 11-13, and the inner cover 70 is provided with an inner through-hole 71. Therefore, the adhesive A is preferably placed in close contact with the main terminals 11-13 around their entire circumference so that the lid through-hole 31 and the inner through-hole 71 do not communicate with each other. Here, the adhesive A, which is spread out by the lid 30, may partially enter the inner through-hole 71 of the inner cover 70 and the lid through-hole 31 of the lid 30. The lid 30 and the inner cover 70 can be fixed together by using adhesive A as a sealing material to seal the space between the lid 30 and the inner cover 70 around the main terminals 11-13. However, a sealing material that does not have adhesive properties may be used instead of adhesive A.

[0040] In this embodiment, only the main terminals 11-13 are inserted into the through-hole 31 of the lid 30, so adhesive A seals the space between the lid 30 and the inner cover 70 around the main terminals 11-13. However, in a configuration where the auxiliary terminals 14-17 are also inserted into the through-hole 31 of the lid 30, it is preferable to seal the space between the lid 30 and the inner cover 70 around the auxiliary terminals 14-17 with a sealing material such as adhesive A.

[0041] Furthermore, in this embodiment, the main terminals 11-13 (and auxiliary terminals 14-17) are insert-molded with the case 20, but the main terminals 11-13 do not necessarily have to be insert-molded with the case 20. In that case, the gap between the main terminals 11-13 and the case 20 may become larger, so it is particularly effective to place the adhesive A so that it is in close contact with the main terminals 11-13 around their entire circumference.

[0042] Figures 11 and 12 are perspective and plan views, respectively, of the semiconductor module 101 in the comparative example.

[0043] The semiconductor module 101 shown in Figures 11 and 12 differs from the semiconductor module 1 according to this embodiment mainly in that the case 120 is not insert-molded with the main terminals 11-13 and auxiliary terminals 14-17, and the cover 30 is omitted.

[0044] The case 120 has a main body 121 and a nut glove 122 positioned at the opening 121b of the main body 121 for fixing the screws of the external terminals mentioned above to the main terminals 11 to 13. In this comparative example, the main terminals 11 to 13 are not bent at the tip as described above, but are metal members with a downward-facing U-shaped plate.

[0045] The main body 121 is provided with fastening holes 121a at its four corners for fixing the case 120 together with the heat dissipation base 40 to a cooler (not shown). The nut globe 122 is inserted from the negative end in the X direction to the positive end in the X direction of the opening 121b of the main body 121 after the main body 121 has been placed over the semiconductor element 50 and the wiring board 60 so that the main terminals 11-13 and auxiliary terminals 14-17 are exposed to the outside. As a result, with the nut globe 122 sandwiching the main terminals 11-13 between itself and the side wall of the opening 121b, each nut N of the nut globe 122 is positioned below the main terminal through holes 11a, 12a, and 13a of the main terminals 11-13.

[0046] In this comparative example, a gap is created between the opening 121b of the main body 121 and the nut glove 122 in case 120. This gap can be sealed from the outside of case 120 with a sealant such as adhesive, but it is not possible to supply the sealant to the gap on the back side of the main terminals 11-13. Furthermore, supplying the sealant from the outside of case 120 results in an unsightly appearance and the sealant is prone to peeling off. When the sealant peels off, not only is debris generated, but corrosive gases also enter through the gap.

[0047] The difficulty in sealing the gap with a sealant from the outside is the same in this embodiment, even when the inner cover 70 and the adhesive A that seals the space between the inner cover 70 and the lid 30 are omitted, and adhesive A is supplied from the outside of the lid 30 between the lid through hole 31 and the main terminals 11-13.

[0048] In the embodiment described above, the semiconductor module 1 comprises a semiconductor element 50, a wiring board 60 on which the semiconductor element 50 is mounted, a frame-shaped case 20 that houses the semiconductor element 50 and the wiring board 60, main terminals 11 to 13 which are an example of terminals electrically connected to the wiring board 60, a lid 30 having a lid through hole 31 into which the main terminals 11 to 13 are inserted and which closes the housing space S for the semiconductor element 50 and the wiring board 60, an inner cover 70 having an inner through hole 71 into which the main terminals 11 to 13 are inserted and which is placed in the housing space S, and an adhesive A which is an example of a sealing material that seals the space between the lid 30 and the inner cover 70 around the main terminals 11 to 13.

[0049] By sealing the space between the lid 30 and the inner cover 70 around the main terminals 11-13 in this manner, it is possible to prevent corrosive gases (hydrogen sulfide, sulfuric acid, etc.) from flowing in through the lid through-hole 31 of the lid 30. Therefore, according to this embodiment, it is possible to prevent corrosive gases from flowing in through the gap between the lid 30, which closes the housing space S of the semiconductor element 50, and the main terminals 11-13 (terminals). This suppresses the growth of corrosion products such as dendrites (tree-like crystals) and, consequently, dielectric breakdown inside the semiconductor module 1, thereby improving the reliability of the semiconductor module 1. Furthermore, since the semiconductor module 1 can be used in highly corrosive environments, the applications of the semiconductor module 1 are expanded. Moreover, in this embodiment, the adhesive A does not fill the gap between the lid through-hole 31 and the main terminals 11-13 outside the lid 30, but rather seals the space between the lid 30 and the inner cover 70 inside the lid 30, thus suppressing deterioration of appearance due to exposure of the adhesive A. Furthermore, compared to the configuration in which adhesive A is supplied to the outside of the lid 30, adhesive A is less likely to peel off, thus reliably preventing the inflow of corrosive gases.

[0050] Furthermore, in this embodiment, the sealing material (adhesive A) that seals the space between the lid 30 and the inner cover 70 is arranged in close contact with the main terminals 11 to 13 around their entire circumference.

[0051] Therefore, the inflow of corrosive gas from the inner through-hole 71 is prevented due to the communication between the through-hole 31 (external) of the lid 30 and the inner through-hole 71 of the inner cover 70. Consequently, the inflow of corrosive gas from the gap between the lid 30 and the main terminals 11-13 (terminals) can be further prevented.

[0052] In this embodiment, the main terminals 11 to 13 are insert-molded with the case 20.

[0053] Therefore, it is possible to prevent corrosive gases from entering through the gap between the main terminal 11 and the terminal holding part 22 (case 20). Consequently, it is possible to further prevent corrosive gases from entering through the gap between the lid 30 and the main terminals 11 to 13 (terminals).

[0054] In this embodiment, the case 20 also includes a frame-shaped main body portion 21 located around the housing space S for the semiconductor element 50 and the wiring board 60, a terminal holding portion 22 for holding the main terminals 11 to 13, and a beam portion 23 connecting the main body portion 21 and the terminal holding portion 22.

[0055] As a result, the terminal holding portion 22 can hold the main terminals 11-13 in the housing space S for the semiconductor element 50 and the wiring board 60. Therefore, it is also possible to suppress the inflow of corrosive gas from the inner through hole 71 of the inner cover 70. Consequently, the inflow of corrosive gas from the gap between the lid 30 and the main terminals 11-13 (terminals) can be further prevented.

[0056] In this embodiment, the inner cover 70 is supported by the terminal holding portion 22.

[0057] This stabilizes the position of the inner cover 70, allowing for a more secure seal between the lid 30 and the inner cover 70. Therefore, it is possible to further prevent the inflow of corrosive gases through the gap between the lid 30 and the main terminals 11-13 (terminals).

[0058] Furthermore, in this embodiment, the inner cover 70 has a plurality of inner through holes 71 into which the main terminals 11 to 13 are inserted.

[0059] As a result, compared to the modified example shown in Figure 8 in which an inner cover 80 is placed for each of the main terminals 11 to 13, a simpler configuration can be used to prevent corrosive gases from entering through the gap between the lid 30 and the main terminals 11 to 13 (terminals).

[0060] Furthermore, in this embodiment, the sealing material that seals the space between the lid 30 and the inner cover 70 around the main terminals 11 to 13 is adhesive A.

[0061] This allows the lid 30 and the inner cover 70 to be fixed together by the adhesive A used for sealing, stabilizing the position of the inner cover 70, and thus ensuring a more reliable seal between the lid 30 and the inner cover 70. Consequently, the inflow of corrosive gases through the gap between the lid 30 and the main terminals 11-13 (terminals) can be further prevented. Furthermore, since the adhesive A surrounds and adheres to the main terminals 11-13 360 degrees, the inflow path of corrosive gases can be completely blocked, preventing the adverse effects of corrosive gases.

[0062] In this embodiment, the terminals that seal the space between the lid 30 and the inner cover 70 around their periphery are the main terminals 11 to 13.

[0063] Therefore, for the main terminals 11-13, which are larger than the auxiliary terminals 14-17 and tend to create gaps between them and the lid 30, and which tend to be positioned to extend upward (positive Z-direction) in the housing space S, it is possible to prevent corrosive gases from entering through the gaps between them and the lid 30.

[0064] Furthermore, in this embodiment, the main terminals 11 to 13 are bent at the tip portion that protrudes from the cover 30.

[0065] Therefore, the adhesive A that seals the gap between the lid 30 and the inner cover 70 can prevent corrosive gases from entering from the back of the bent portion of the gap between the main terminals 11-13 and the through-hole 31 of the lid 30, which is difficult to seal.

[0066] Figure 9 is a plan view showing a case 20 in which the main terminals 11-13 and auxiliary terminals 14-17 are insert-molded in another embodiment. Figure 10 is a cross-sectional view of Figure 9 XX.

[0067] In this embodiment, instead of the inner covers 70 and 80 supported by the terminal holding portion 22, three inner covers 25 are integrally provided on the case 20. Other matters can be described in the same manner as above, so a detailed explanation is omitted.

[0068] In this embodiment, the inner cover 25, rather than the terminal holding portion 22, is connected to the main body portion 21 by the beam portion 23. The three inner covers 25 then hold the main terminals 11 to 13. Therefore, as shown in Figure 10, the inner cover 25 extends longer in the positive Z direction than the terminal holding portion 22 shown in Figure 7.

[0069] As shown in Figure 10, adhesive A, an example of a sealing material, is placed on the upper surface of the inner cover 25. When the lid 30 is placed over the case 20, adhesive A is spread around the main terminals 11-13, sealing the space between the lid 30 and the inner cover 25. Here, since the main terminals 11-13 are insert-molded into the inner cover 25, there is virtually no gap between the inner through-hole 25a of the inner cover 25 and the main terminals 11-13. However, it is preferable that adhesive A is placed in close contact with the main terminals 11-13 around their entire circumference. Some of the adhesive A spread by the lid 30 may enter the lid through-hole 31 of the lid 30. By using adhesive A as a sealing material to seal the space between the lid 30 and the inner cover 25 around the main terminals 11-13, the lid 30 and the inner cover 25 (case 20) can be fixed together. However, a non-adhesive sealing material may be used instead of adhesive A. Furthermore, instead of three (an example of multiple) inner covers 25, only one may be provided, and a single, integrally provided inner cover 25 may hold the three main terminals 11-13.

[0070] In the other embodiments described above, similar effects can be obtained with respect to matters similar to those of the above-described embodiment, namely, the effect of preventing the inflow of corrosive gas from the gap between the lid 30 that seals the housing space S of the semiconductor element 50 and the main terminals 11 to 13 (terminals).

[0071] In the other embodiments described above, the inner cover 25 is integrally provided with the case 20 and holds the main terminals 11 to 13. The case 20 has a frame-shaped main body portion 21 located around the housing space S and a beam portion 23 connecting the main body portion 21 and the inner cover 25.

[0072] This allows for a simpler configuration compared to a configuration in which inner covers 70 and 80 are arranged separately from the case 20, and prevents corrosive gases from entering through the gap between the lid 30 and the main terminals 11 to 13 (terminals).

[0073] The semiconductor module according to the present invention is not limited to the embodiments described above, and may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way by technological advancements or other derived technologies, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea.

[0074] The following are some of the inventions described in the specification and drawings of this application.

[0075] <Note 1> Semiconductor elements and A wiring board on which the aforementioned semiconductor elements are mounted, A frame-shaped case for housing the semiconductor element and the wiring board, Terminals electrically connected to the aforementioned wiring board, A lid having a through-hole into which the terminal is inserted, and a lid that closes the housing space for the semiconductor element and the wiring board, An inner cover having an inner through-hole into which the terminal is inserted, and positioned in the housing space, A sealing material that seals the space between the lid and the inner cover around the terminal. A semiconductor module characterized by comprising the following features.

[0076] <Note 2> The sealing material is arranged in close contact with the terminal around its entire circumference. A semiconductor module as described in Appendix 1, characterized by the features described herein.

[0077] <Note 3> The terminal is insert-molded with the case. A semiconductor module as described in Appendix 1 or 2, characterized by the above.

[0078] <Note 4> The case comprises a frame-shaped main body located around the periphery of the housing space, a terminal holding portion for holding the terminals, and a beam portion connecting the main body and the terminal holding portion. The semiconductor module described in Appendix 3, characterized by the features described herein.

[0079] <Note 5> The inner cover is supported by the terminal holding portion. A semiconductor module as described in Appendix 4, characterized by the features described herein.

[0080] <Note 6> The inner cover has a plurality of inner through holes The semiconductor module described in Appendix 5, characterized by the features described herein.

[0081] <Note 7> The inner cover is integrally provided with the case and holds the terminals. The case has a frame-shaped main body located around the storage space and a beam connecting the main body and the inner cover. The semiconductor module described in Appendix 3, characterized by the features described herein.

[0082] <Note 8> The aforementioned sealing material is an adhesive. A semiconductor module characterized by any one of the appendices 1 to 7.

[0083] <Note 9> The aforementioned terminal is the main terminal. A semiconductor module characterized by any one of the appendices 1 to 8.

[0084] <Note 10> The terminal is bent at the tip portion that protrudes from the lid. A semiconductor module characterized by any one of the appendices 1 to 9. [Industrial applicability]

[0085] As described above, the present invention has the effect of preventing corrosive gases from entering through the gap between the lid that seals the housing space of the semiconductor element and the terminals, and is particularly useful for inverter devices for industrial or electrical applications. [Explanation of Symbols]

[0086] 1. Semiconductor module 11~13 Main terminal 11a,12a,13a Main terminal through hole 14-17 Auxiliary terminals 20 cases 21 Main body 21a Fastening hole 21b Support recess 22 Terminal holding part 23 Beam section 25 Inner cover 25a Inner through hole 30 Lid 31 Lid through hole 32 Nut housing section 40 Heat dissipation base 41 Fastening hole 50 Semiconductor elements 50-1 Switching element 50-2 Diode element 60 Wiring board 61. First Conductor Layer 62 Second Conductor Layer 63 Insulating layer 70 Inner Cover 71 Inner through hole 80 Inner Cover 81 Inner through hole 101 Semiconductor Modules 120 cases 121 Main body 121a Fastening hole 121b opening 122 Nut Gloves A. Adhesive (sealant) G Sealing Gel J1~J8 terminal joint N Nut S Containment space W wiring

Claims

1. Semiconductor elements and A wiring board on which the aforementioned semiconductor elements are mounted, A frame-shaped case for housing the semiconductor element and the wiring board, Terminals electrically connected to the aforementioned wiring board, A lid having a through-hole into which the terminal is inserted, and a lid that closes the housing space for the semiconductor element and the wiring board, An inner cover having an inner through-hole into which the terminal is inserted, and positioned in the housing space, A sealing material that seals the space between the lid and the inner cover around the terminal. A semiconductor module characterized by comprising the following features.

2. The sealing material is arranged in close contact with the terminal around its entire circumference. The semiconductor module according to claim 1, characterized in that it is a semiconductor module.

3. The terminal is insert-molded with the case. The semiconductor module according to claim 1, characterized in that it is a semiconductor module.

4. The case comprises a frame-shaped main body located around the periphery of the housing space, a terminal holding portion for holding the terminals, and a beam portion connecting the main body and the terminal holding portion. The semiconductor module according to claim 3, characterized in that it is as described above.

5. The inner cover is supported by the terminal holding portion. The semiconductor module according to claim 4, characterized in that it is a semiconductor module.

6. The inner cover has a plurality of inner through holes The semiconductor module according to claim 5, characterized in that it is a semiconductor module.

7. The inner cover is integrally provided with the case and holds the terminals. The case has a frame-shaped main body located around the storage space and a beam connecting the main body and the inner cover. The semiconductor module according to claim 3, characterized in that it is as described above.

8. The aforementioned sealing material is an adhesive. The semiconductor module according to claim 1, characterized in that it is a semiconductor module.

9. The aforementioned terminal is the main terminal. The semiconductor module according to claim 1, characterized in that it is a semiconductor module.

10. The terminal is bent at the tip portion that protrudes from the lid. The semiconductor module according to claim 1, characterized in that it is a semiconductor module.

Images