Semiconductor device

Abstract

To reduce torque applied to a case when an external conductor is fastened to a main terminal in a semiconductor device.SOLUTION: A semiconductor device 1 includes: a semiconductor element 12; a main terminal (for example, P terminal 40, N terminal 50 and M terminal 60) that has a fastened portion 41 (51, 61) including a fastening hole 41a (51a, 61a) and fastened to an external conductor C1 (C2, C3) in the fastening hole by a screw S and a nut N, and an extending portion 42 (52, 62) extending from the fastened portion 41 to a semiconductor element 12 side and electrically connected to the semiconductor element 12; and a case 30 that accommodates the semiconductor element 12 therein. The case 30 has a recess 32 (33, 34) that accommodates the nut N therein. The main terminal further has a bent portion 43 (63) that is bent from a periphery of the fastened portion 41, the periphery being different from an extending portion 42 side, and that enters between the nut N and a wall surface of the recess 32 in the case 30.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a semiconductor device having a case that houses a nut for fastening an outer conductor to a main terminal. [Background technology]

[0002] Conventionally, some semiconductor devices include a main terminal electrically connected to a semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) and an external conductor (see, for example, Patent Documents 1 to 4). In addition, a method for fastening multiple members is to use bolts (see, for example, Patent Documents 5 and 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-120390 [Patent Document 2] JP 2002-076255 A [Patent Document 3] Patent Publication No. 2022-096958 [Patent Document 4] JP 2021-190553 A [Patent Document 5] JP 2002-039141 A [Patent Document 6] JP 2012-209165 A Summary of the Invention [Problem to be solved by the invention]

[0004] In some semiconductor devices, the case that houses the semiconductor element houses a nut for fastening the external conductor to the main terminal. In this type of semiconductor device, when the external conductor is fastened to the main terminal by a screw, a torque is applied from the nut to the case. As a result, a configuration that ensures the strength of the case, such as a configuration that makes the case thick, is adopted, which makes it difficult to miniaturize the semiconductor device.

[0005] An object of the present invention is to provide a semiconductor device capable of reducing the torque applied to the case when an outer conductor is fastened to a main terminal. [Means for solving the problem]

[0006] In one aspect, a semiconductor device comprises a semiconductor element, a main terminal having a fastening portion including a fastening hole and fastened to an external conductor by a screw and a nut in the fastening hole, and an extension portion extending from the fastening portion toward the semiconductor element and electrically connected to the semiconductor element, and a case for accommodating the semiconductor element, the case having a recess for accommodating the nut, and the main terminal further having a bent portion bent from a periphery of the fastening portion different from the extended portion side and extending between a wall surface of the recess in the case and the nut. Effect of the Invention

[0007] According to this aspect, it is possible to reduce the torque applied to the case when the outer conductor is fastened to the main terminal. [Brief description of the drawings]

[0008] [Figure 1] 1 is a plan view showing a semiconductor device according to an embodiment; [Diagram 2] 1 is a right side view perspectively illustrating an internal configuration of a semiconductor device according to an embodiment; [Diagram 3] 2A to 2C are a plan view, a front view, a right side view, and an exploded view of a P terminal in one embodiment. [Figure 4]1A to 1C are a plan view, a front view, a right side view, and an exploded view of a P terminal in a first modified example of the embodiment. [Diagram 5] 13A to 13C are a plan view, a front view, a right side view, and a development view of a P terminal in a second modified example of the embodiment. [Figure 6] 13A to 13C are a plan view, a front view, a right side view, and an exploded view of a P terminal in a third modified example of the embodiment. [Figure 7] FIG. 13 is a development view of a P terminal in a fourth modified example of the embodiment. [Figure 8] FIG. 13 is a development view of a P terminal in a fifth modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below, and can be appropriately modified and implemented without departing from the gist of the present invention.

[0010] 1 and 2 are a plan view and a right side view showing a perspective internal configuration of a semiconductor device 1 according to an embodiment.

[0011] 1 and 2 and 3 to 6 described later, the vertical direction of the semiconductor device 1 (thickness direction of the laminated substrate 11) is defined as the Z direction, and of the X and Y directions perpendicular to the Z direction, the longitudinal direction of the semiconductor device 1 is defined as the X direction, and the lateral direction of the semiconductor device 1 is defined as the Y direction. In some cases, the X direction may be called the left-right direction, the Y direction may be called the front-back direction, and the Z direction may be called the up-down direction. These directions are terms used for convenience of explanation, and the corresponding relationships between the X, Y, and Z directions change depending on the mounting posture of the semiconductor device 1.

[0012] The semiconductor device 1 according to the present embodiment is applied to a power conversion device such as a power control unit, and is a power semiconductor module constituting an inverter circuit. The semiconductor device 1 can be used for any purpose, but is used, for example, as an inverter device for an in-vehicle or industrial motor.

[0013] 1 includes, for example, three unit modules 10, a metal base 20 (see FIG. 2), a case 30, and a P terminal 40, an N terminal 50, and an M terminal 60 arranged for each unit module 10. For example, the semiconductor device 1 is used together with a cooler (not shown) arranged below the metal base 20 with a sealing resin or gel (not shown) injected into the case 30.

[0014] The unit module 10 includes a laminated substrate 11, a semiconductor element 12 arranged on the laminated substrate 11, and a metal wiring board 13. In this embodiment, three unit modules 10 are arranged side by side in the X direction. The three unit modules 10 constitute, for example, a U phase, a V phase, and a W phase, and together form a three-phase inverter circuit. The unit modules 10 may be called power cells or semiconductor units. Any number of unit modules 10 greater than or equal to one may be arranged.

[0015] The laminated substrate 11 is formed of, for example, a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Brazing) substrate, or a metal-based substrate. As shown in Fig. 2, the laminated substrate 11 has, for example, an insulating plate 11a, a heat sink 11b disposed on the lower surface of the insulating plate 11a, and a plurality of circuit plates 11c disposed on the upper surface of the insulating plate 11a. The laminated substrate 11 is formed, for example, in a rectangular shape in a plan view.

[0016] The insulating plate 11a is formed of an insulating material such as a ceramic material, such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), a composite material of aluminum oxide and zirconium oxide (ZrO2), a resin material, such as epoxy, or an epoxy resin material using a ceramic material as a filler. The insulating plate 11a may be called an insulating layer or an insulating film.

[0017] The heat sink 11b has a predetermined thickness in the Z direction and is formed on the lower surface of the insulating plate 11a. The heat sink 11b is made of a metal plate having good thermal conductivity, such as copper or aluminum. The heat sink 11b is joined to the upper surface of the metal base 20 by a joining material J1 such as solder.

[0018] As shown in Fig. 1, three circuit boards 11c are formed on the upper surface of insulating plate 11a. The number of circuit boards 11c formed on the upper surface of insulating plate 11a may be any number equal to or greater than one. Circuit boards 11c are metal layers such as copper foil, and are formed in islands on insulating plate 11a while being electrically insulated from one another. Circuit boards 11c may also be called circuit layers.

[0019] As shown in Fig. 2, a semiconductor element 12 is disposed on a mounting surface, which is the upper surface of the laminated substrate 11 (circuit board 11c), via a bonding material J2. Although two semiconductor elements 12 are shown for one laminated substrate 11 in Fig. 1, the number of semiconductor elements 12 is arbitrary. The semiconductor element 12 is formed in a square or rectangular shape in a plan view using a semiconductor substrate such as silicon (Si), silicon carbide (SiC), gallium nitride (GaN), diamond, or the like.

[0020] As the semiconductor element 12, a switching element such as an IGBT or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), or a diode such as an FWD (Free Wheeling Diode) may be used. The switching element and the diode may be connected in inverse parallel. As the semiconductor element 12, an RC (Reverse Conducting)-IGBT element in which an IGBT and an FWD are integrated, or a power MOSFET element, or an RB (Reverse Blocking)-IGBT having a sufficient withstand voltage against reverse bias, may be used. In particular, the RC-IGBT element can reduce the size of the internal circuit by passing electricity in both directions, and thus the size of the semiconductor device 1 (laminated substrate 11).

[0021] The semiconductor element 12 is conductively connected to a predetermined circuit board 11c via a metal wiring board 13. The metal wiring board 13 is formed by bending a metal material such as copper, copper alloy, aluminum alloy, or iron alloy by pressing or the like. For example, the semiconductor element 12 and the metal wiring board 13 are joined by a joining material such as solder. These metal wiring boards 13 may be called lead frames. Note that other connecting members such as conductor wires may be disposed instead of the metal wiring board 13.

[0022] The metal base 20 shown in Fig. 2 is a rectangular plate-shaped member. The metal base 20 functions as a heat-conducting member that conducts heat generated by the semiconductor element 12 to a cooler (not shown) located below the metal base 20, and is formed of a metal plate such as a copper plate or an aluminum plate. The metal base 20 and the cooler are joined together via a heat-conducting material such as thermal grease or thermal compound.

[0023] 1, the case 30 is formed in a rectangular frame shape having a hollow portion 31 in the center. The above-mentioned three unit modules 10 are housed in the rectangular hollow portion 31. That is, the three unit modules 10 are housed in a space defined by the frame-shaped case 30.

[0024] 2, the recesses 32, 33, and 34 have nut accommodating portions 32a, 34a and screw accommodating portions 32b, 34b. The recesses 32, 33, and 34 are recessed from the upper surface of the case 30 toward the metal base 20. Although the nut accommodating portion and the screw accommodating portion of the recess 33 are not shown, the recess 33 can have the same configuration as the recesses 32 and 34.

[0025] The nut accommodating portions 32a, 34a accommodate a nut N that is screwed into the threaded portion of the screw S. The nut accommodating portions 32a, 34a may have any shape, for example, a rectangular shape in a plan view. The screw S and the nut N are members for fastening the outer conductors C1, C2, C3 to the fastened portions 41, 51, 61 in the fastening holes 41a, 51a, 61a described below. As the nut N, any nut may be used, such as a hexagonal tubular nut or a hexagonal cap nut without a female screw hole.

[0026] The screw accommodating portions 32b, 34b accommodate the tip of the threaded portion of the screw S. The screw accommodating portions 32b, 34b may have any shape, for example, a circular shape in plan view. The screw accommodating portions 32b, 34b are smaller in size in plan view than the nut accommodating portions 32a, 34a, and the nut N is placed on the step between the nut accommodating portions 32a, 34a and the screw accommodating portions 32b, 34b. However, the nut accommodating portions 32a, 34a and the screw accommodating portions 32b, 34b may have the same size in plan view, and the nut accommodating portions 32a, 34a and the screw accommodating portions 32b, 34b may not be separated from each other.

[0027] 2, recesses 32, 33, 34 (nut accommodating portions 32a, 34a) are formed between a side surface of case 30 on the semiconductor element 12 side and a side surface of case 30 facing the side surface of case 30 on the semiconductor element 12 side. In this case, extension portion 42 passes through the inside of case 30 from fastened portion 41 and protrudes from the side surface of case 30 on the semiconductor element 12 side toward hollow portion 31. Also, recesses 32, 33, 34 may be recessed deeper from the upper surface of case 30 so that at least a part of fastened portions 41, 51, 61 of each terminal 40, 50, 60 can be inserted therein.

[0028] A plurality of through holes 35 are formed along the outer periphery of the case 30. The through holes 35 are holes for inserting bolts for fixing the semiconductor device 1 to an external device such as a cooler (not shown), for example.

[0029] The resin for the case 30 may be selected from insulating resins such as polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), polybutyl acrylate (PBA), polyamide (PA), acrylonitrile butadiene styrene (ABS), liquid crystal polymer (LCP), polyether ether ketone (PEEK), polybutylene succinate (PBS), urethane, silicone, etc. The selected resin may be a mixture of two or more types of resin. The resin may contain a filler (e.g., glass filler) to improve strength or functionality.

[0030] Furthermore, a sealing resin or gel (not shown) injected into the internal space defined by the frame-shaped case 30 seals the laminated substrate 11 and the semiconductor element 12 mounted on the laminated substrate 11 within the space. The sealing resin is, for example, made of a thermosetting resin. The sealing resin preferably contains any of epoxy, silicone, urethane, polyimide, polyamide, and polyamideimide. For example, an epoxy resin mixed with a filler is suitable as the sealing resin in terms of insulation, heat resistance, and heat dissipation. Furthermore, the gel is, for example, a silicone gel.

[0031] The case 30 is provided with main terminals (P terminal 40, N terminal 50, and M terminal 60) that function as external connection terminals for connection with external conductors C1, C2, and C3 (see FIG. 2), and control terminals for control (not shown). Each of the P terminal 40, N terminal 50, and M terminal 60 is arranged for each unit module 10. The P terminal 40 may be called a positive terminal (input terminal) or a first main terminal, the N terminal 50 may be called a negative terminal (output terminal) or a second main terminal, and the M terminal 60 may be called an intermediate terminal (output terminal) or a third main terminal.

[0032] The P terminal 40 and the N terminal 50 are located on the negative side in the Y direction with respect to the laminated substrate 11. Moreover, the M terminal 60 is located on the positive side in the Y direction with respect to the laminated substrate 11. The P terminal 40, the N terminal 50, and the M terminal 60 may be formed by bending a metal material such as a copper material, a copper alloy material, an aluminum alloy material, or an iron alloy material by pressing or the like.

[0033] The P terminal 40, the N terminal 50, and the M terminal 60 have fastened portions 41, 51, and 61, and extending portions 42, 52, and 62 that extend from the fastened portions 41, 51, and 61 toward the semiconductor element 12 side.

[0034] The fastened parts 41, 51, 61 include fastening holes 41a, 51a, 61a, and are fastened to the outer conductors C1, C2, C3 by screws S and nuts N. The fastened parts 41, 51, 61 have a rectangular shape in a plan view. The fastening holes 41a, 51a, 61a penetrate the fastened parts 41, 51, 61 in the Z direction. The fastening holes 41a, 51a, 61a have, for example, an inner circumferential surface with a constant shape in the height direction. Note that the fastened parts 41, 51, 61 are fastened to the outer conductors C1, C2, C3 while placed on the case 30, so that the fastened parts 41, 51, 61 (each of the terminals 40, 50, 60) can be said to be held by the case 30. When at least a portion of the fastened portions 41, 51, 61 is inserted into the recesses 32, 33, 34 of the case 30 as described above, the case 30 holds the P terminals 40, 50, 60 in a more stable state.

[0035] The extension parts 42, 52, 62 are bent downward (Z direction negative side) from the fastened parts 41, 51, 61 that extend horizontally, bent horizontally (Y direction side), bent downward again (Z direction negative side), and bent horizontally again (Y direction side). The extension parts 42, 52, 62 are joined at the ends opposite to the fastened parts 41, 51, 61 to the circuit board 11c or a copper block (not shown) provided on the circuit board 11c. The extension parts 42, 52, 62 are electrically connected to the semiconductor element 12 via the circuit board 11c. The extension parts 42, 52, 62 may abut against the nut N at the parts bent downward from the fastened parts 41, 51, 61, for example. As described above, the extending portions 42, 52, 62 extend from the fastened portions 41, 51, 61 while bending, but may not be bent from the fastened portions 41, 51, 61 and may extend on the same plane as the fastened portions 41, 51, 61. The extending portions 42, 52, 62 are shorter in width in the X direction than the fastened portions 41, 51, 61, but may have a width in the X direction equal to or greater than that of the fastened portions 41, 51, 61.

[0036] In the above explanation, three examples of main terminals are given: the P terminal 40, the N terminal 50, and the M terminal 60; therefore, the number of recesses 32, 33, 34, nuts N, etc. of the case 30 is also three; however, the number of main terminals, recesses 32, 33, 34, nuts N, etc. in this embodiment can be any number equal to or greater than one.

[0037] Next, details of the bent portions 43, 63 of the P terminal 40, N terminal 50, and M terminal 60 will be described using the P terminal 40 as an example with reference to Fig. 3. Note that the bent portion of the N terminal 50 is not shown, and as for the bent portion 63 of the M terminal 60, only a small portion of the bent portion 63 located on the negative side of the nut N in the X direction is shown in Fig. 2, but the N terminal 50 and the M terminal 60 can be configured similarly to the P terminal 40.

[0038] Fig. 3 shows (a) a plan view, (b) a front view, (c) a right side view, and (d) a development view of the P terminal 40. The dashed and dotted lines shown in the development views of Fig. 3(d), Fig. 4(d), Fig. 5(d), Fig. 6(d), Fig. 7, and Fig. 8 indicate the folding lines (mountain fold lines) of the P terminal 40. In Fig. 3 and Fig. 4 to Fig. 6 described later, the leading lines of the parts indicated by hidden lines (dashed lines) are indicated by dashed lines.

[0039] 3(a) to (d), the P terminal 40 has the above-mentioned fastened portion 41 and the extending portion 42, and a pair of bent portions 43, 43 bent from the fastened portion 41. These bent portions 43, 43 are an example of a peripheral edge of the fastened portion 41 different from the extending portion 42 side (positive side in the Y direction), and are bent downward (negative side in the Z direction) from both ends of the fastened portion 41 in the width direction (X direction) of the P terminal 40 intersecting with the extending direction (Y direction) of the extending portion 42. As shown in FIGS. 3(a) and 3(b), the bent portions 43, 43 enter between the wall surfaces (left and right side surfaces) of the recess 32 of the case 30 and the nut N.

[0040] As shown in Figures 3(a) to (c), the fastened portion 41 and the folded portions 43, 43 are formed to a size that fits into the recess 32 of the case 30 in a plan view, and it is desirable that the folded portions 43, 43 abut against both the wall surfaces (left and right side surfaces) of the recess 32 and the side surfaces Na (left and right side surfaces) of the nut N.

[0041] Here, it is preferable that the front corner of the nut N and the front surface of the recess 32 are positioned at a distance so that torque is not applied directly from the nut N to the wall surface of the recess 32 without passing through the bent portion 43. It is also preferable that the rear corner of the nut N and the extension portion 42 are positioned at a distance so that torque is not applied from the rear corner of the nut N to the extension portion 42.

[0042] The bent portions 43, 43 have the same lower end position as one side surface Na (left and right side surfaces) of the nut N that they abut. The bent portions 43, 43 are formed to have a width in the Y direction longer than one side surface Na of the nut N. That is, the bent portions 43, 43 are formed larger than the side surface Na of the nut N. The bent portions 43, 43 abut the entire side surface Na of the nut N, and preferably extend in at least one of the width direction (Y direction) and height direction (Z direction) from the abutting portion. Note that one of the pair of left and right bent portions 43, 43 may be omitted, but the single bent portion 43 is preferably a single bent portion 143 that faces the extension portion 142 and sandwiches the nut N as shown in FIG. 4 described later, and it is preferable that a plurality of bent portions 43 that do not face the extension portion 42 are provided so as to face each other and sandwich the nut N.

[0043] Hereinafter, first to fifth modified examples of this embodiment will be described with reference to Figures 4 to 8. Note that the fastened parts 141, 241, 341, 441, 541 and the extending parts 142, 242, 342, 442, 542 of each modified example can be similar to the fastened part 41 and the extending part 42 described above, and therefore the description will be omitted. In addition, the N terminal and the M terminal can also be configured similarly to the P terminals 140, 240, 340, 440, 540, and therefore the description will be omitted.

[0044] 4A, 4B, 4C, and 4D are a plan view, a front view, a right side view, and a development view, respectively, of a P terminal 140 in a first modified example.

[0045] As shown in Figs. 4(a) to (d), the P terminal 140 has a fastened portion 141 including a fastening hole 141a, an extending portion 142 extending from the fastened portion 141, and a bent portion 143 bent from the fastened portion 141. The bent portion 143 is an example of a periphery different from the extending portion 142 side (positive side in the Y direction) of the fastened portion 141, and is bent downward from the periphery of the end portion of the fastened portion 141 on the opposite side (negative side in the Y direction) from the extending portion 142. As shown in Figs. 4(a) and (c), the bent portion 143 enters between the wall surface (front surface) of the recess 32 of the case 30 and the side surface Na (front surface) of the nut N. The bent portion 143 faces the extending portion 142 and is shaped to sandwich the nut N.

[0046] 4(a) to 4(c), the fastened portion 141 and the bent portion 143 are formed to a size that can be accommodated in the recess 32 of the case 30 in a plan view, and it is preferable that the bent portion 143 abuts against both the wall surface (front surface) of the recess 32 and the side surface Na (front surface) of the nut N. In addition, it is preferable that the rear surface of the nut N abuts against the extending portion 142.

[0047] The six outer peripheral surfaces of the nut N are oriented differently from the example shown in FIG. 3, and the front surface extending in the XZ plane constitutes one of the side surfaces Na. The left and right corners of the nut N and the left and right side surfaces of the recess 32 are preferably positioned at intervals so that torque is not directly applied from the nut N to the wall surface of the recess 32 without passing through the bent portion 143. The bent portion 143 has the same lower end position as the side surface Na (front surface) of the nut N that it abuts. The bent portion 143 is formed to have a longer width in the X direction than one of the side surfaces Na of the nut N. That is, the bent portion 143 is formed larger than the side surface Na (front surface) of the nut N. The bent portion 143 abuts against the entire side surface Na (front surface) of the nut N, and preferably extends beyond this abutting portion in at least one of the width direction (X direction) and height direction (Z direction).

[0048] FIG. 5 is a plan view (a), a front view (b), a right side view (c), and a development view (d) of a P terminal 240 in the second modified example.

[0049] As shown in Figs. 5(a) to (d), the P terminal 240 has a fastened portion 241 including a fastening hole 241a, an extending portion 242 extending from the fastened portion 241, and a bent portion 243 bent from the fastened portion 241. The bent portion 243 is an example of a periphery different from the extending portion 242 side (positive side in the Y direction) of the fastened portion 241, and is bent downward from the periphery of the end portion of the fastened portion 241 on the opposite side (negative side in the Y direction) from the extending portion 242, as in the first modified example shown in Fig. 4. As shown in Figs. 5(a) and (c), the bent portion 243 enters between the wall surface (front surface) of the recess 32 of the case 30 and the nut N. The bent portion 243 is shaped to face the extending portion 242 and sandwich the nut N.

[0050] 5(a) to 5(c), the fastened portion 241 and the bent portion 243 are formed to a size that can be accommodated in the recess 32 of the case 30 in a plan view, and it is preferable that the bent portion 243 abuts against the nut N. In the present second modified example, there is a gap in the Y direction between the bent portion 243 (and the front corners of the nut N) and the front surface of the recess 32. Also, the bent portion 243 abuts against the wall surfaces of the recess 32 at both left and right end portions.

[0051] As in the example shown in FIG. 3, the six outer peripheral surfaces of the nut N have corners located at the front and rear, and the left and right side surfaces face the left and right side surfaces of the recess 32. The left and right side surfaces of the nut N and the left and right side surfaces of the recess 32 are preferably located at an interval so that torque is not directly applied from the nut N to the wall surface of the recess 32 without passing through the bent portions 243, 243. The bent portion 243 has an opening 243a through which the corner portion (front side) of the nut N is exposed. The extension portion 242 has an opening 242a through which the corner portion (rear side) of the nut N is exposed. The front corner portion of the nut N penetrates the bent portion 243 (the opening 243a which is a through hole). The rear corner portion of the nut N is located within the opening 243a of the bent portion 243. This opening 243a may be a through hole or a recess recessed toward the nut N side. In plan view, the opening 243a of the bent portion 243 and the opening 242a of the extended portion 242 have a narrower width in the X direction as they move away from the center of the nut N, in accordance with the tapered width of the front and rear corners of the nut N toward the apexes of the front and rear corners of the nut N. As a result, the bent portion 243 and the extended portion 242 abut against the side of the nut N at the openings 243a, 242a to hold the nut N. However, the width of the openings 242a, 243a in the X direction may be constant. The bent portion 243 has the same lower end position as the nut N. The extended portion 242 may not have an opening 242a, as in the extended portion 42 of FIG. 3. In that case, the rear corner of the nut N and the extended portion 242 may be positioned at a distance from each other so that torque is not applied to the extended portion 242 from the rear corner of the nut N. The bent portion 243 may be formed to fit along the side surface of the nut N.

[0052] 6A, 6B, 6C, and 6D are a plan view, a front view, a right side view, and a development view, respectively, of a P terminal 340 in the third modified example.

[0053] As shown in Fig. 6(a) to (d), the P terminal 340 has a fastened portion 341 including a fastening hole 341a, an extending portion 342 extending from the fastened portion 341, and a pair of bent portions 343, 343 bent from the fastened portion 341. These bent portions 343, 343 are an example of a peripheral edge of the fastened portion 341 different from the extending portion 342 side (positive side in the Y direction), and are bent downward from both ends of the fastened portion 341 in the width direction (X direction) of the P terminal 340 intersecting with the extending direction (Y direction) of the extending portion 342, as in the example shown in Fig. 3. The bent portions 343, 343 enter between the wall surfaces (left and right side surfaces) of the recess 32 of the case 30 and the nut N, as shown in Fig. 6(a) and (b).

[0054] 6(a) to 6(c), it is preferable that the fastened portion 341 and the bent portions 343, 343 are formed to a size that can be accommodated in the recess 32 of the case 30 in a plan view, and that the bent portions 343, 343 abut against the nut N. In the present third modified example, there are gaps in the X direction between the bent portion 343 (and the left and right corners of the nut N) and the left and right side surfaces of the recess 32. Also, the bent portion 343 abuts against the wall surfaces of the recess 32 at its front end.

[0055] The six outer peripheral surfaces of the nut N are oriented differently from the example shown in FIG. 3, and the front surface extending in the XZ plane faces the front surface of the recess 32. The front surface of the nut N and the front surface of the recess 32 are preferably positioned at an interval so that torque is not applied directly to the wall surface of the recess 32 from the nut N without passing through the bent portions 343, 343. Each of the bent portions 343, 343 has an opening 343a through which the corners (left and right) of the nut N are exposed. The left and right corners of the nut N penetrate the bent portions 343, 343. In plan view, the openings 343a, 343a of the bent portions 343, 343 have a narrower width in the Y direction as they move away from the center of the nut N, in accordance with the tapered width of the corners of the nut N toward the apex of the corners of the nut N. As a result, the bent portions 343, 343 abut against the side surface of the nut N at the openings 343a, 343a to hold the nut N. However, the width of the openings 343a, 343a in the Y direction may be constant. The bent portion 343 has a lower end at the same position as the nut N. The bent portion 343 may be formed to fit along the side surface of the nut N.

[0056] FIG. 7 is a development view of a P terminal 440 in the fourth modified example.

[0057] As shown in FIG. 7, the P terminal 440 has a fastened portion 441 including a fastening hole 441a, an extending portion 442 extending from the fastened portion 441, and a pair of bent portions 443, 443 and a pair of bent portions 444, 444 bent from the fastened portion 441.

[0058] The P terminal 40 shown in FIG. 3 mentioned above abuts against the left and right side surfaces Na of the nut N only at the bent portions 43, 43 bent downward from both ends of the fastened portion 41 in the width direction (X direction). On the other hand, in the present fourth modified example, the P terminal 440 has a pair of bent portions 443, 443 that abut against the side surface Na of the nut N and the wall surface of the recess 32 like the bent portions 43, 43 of the P terminal 40 shown in FIG. 3, and a pair of bent portions 444, 444 that abut against the two front surfaces of the nut N. In this way, the P terminal 440 abuts against the four side surfaces of the nut N. The pair of bent portions 444, 444 are formed to have the same size as each of the two front surfaces of the nut N, for example. Note that the pair of bent portions 443, 443 may be omitted, and at least one bent portion 444 may be provided.

[0059] FIG. 8 is a development view of a P terminal 540 in the fifth modified example.

[0060] As shown in FIG. 8, the P terminal 540 has a fastened portion 541 including a fastening hole 541a, an extending portion 542 extending from the fastened portion 541, a bent portion 543 bent from the fastened portion 541, and a pair of bent portions 544, 544.

[0061] The P terminal 140 in the first modified example shown in FIG. 4 above abuts against the side Na (front surface) of the nut N at a single bent portion 143 bent downward from the periphery of the end of the fastened portion 141 on the opposite side (negative side in the Y direction) to the extended portion 142. On the other hand, in the present fifth modified example, the P terminal 540 has a bent portion 543 that abuts against the side Na (front surface) of the nut N and the wall surface of the recess 32, similar to the bent portion 143 of the P terminal 140 shown in FIG. 4, and a pair of bent portions 544, 544 that abut against the left and right side surfaces on the front side of the nut N. In this way, the P terminal 540 abuts against the three side surfaces of the nut N. The pair of bent portions 544, 544 are formed, for example, to have the same size as the left and right side surfaces on the front side of the nut N. Note that the bent portion 543 may be omitted, and at least one bent portion 544 may be provided.

[0062] In the present embodiment (and the first to fifth modifications) described above, the semiconductor device 1 includes the semiconductor element 12, main terminals (for example, the P terminal 40, the N terminal 50, and the M terminal 60), and the case 30. The main terminals include fastening portions 41, 51, and 61, and extending portions 42, 52, and 62 that extend from the fastening portions 41, 51, and 61 toward the semiconductor element 12 and are electrically connected to the semiconductor element 12. The fastening portions 41, 51, and 61 include fastening holes 41a, 51a, and 61a, and are fastened to the external conductors C1, C2, and C3 by the screws S and nuts N at the fastening holes 41a, 51a, and 61a. The case 30 accommodates the semiconductor element 12. The case 30 also has recesses 32, 33, and 34 that accommodate the nuts N. The main terminal further has a bent portion 43 (63) that is bent from a peripheral edge of the fastened portion 41, 51, 61 different from the extending portion 42, 52, 62 side and enters between the wall surface of the recessed portion 32, 33, 34 in the case 30 and the nut N.

[0063] As a result, when the external conductors C1, C2, and C3 are fastened to the main terminals (for example, the P terminal 40, the N terminal 50, and the M terminal 60), the bent portion 43 that enters between the wall surface of the recess 32 and the nut N can receive the torque applied from the nut N. Therefore, according to this embodiment, the torque applied to the case 30 when the external conductors C1, C2, and C3 are fastened to the main terminals can be reduced. This can suppress damage to the case 30, and therefore it is possible to omit a configuration for ensuring the strength of the case 30, such as a configuration in which the case 30 is thickened, and to miniaturize the semiconductor device 1. However, if the attachment between the main terminals and the nut N is loose, the contact resistance between the main terminals and the upper surface of the nut N increases, and the main terminals are more likely to generate heat. In order to suppress this contact resistance, it is possible to increase the fastening torque of the screw S. When the fastening torque is increased in this way, the bent portion 43 receives the torque applied from the nut N as in this embodiment, and the torque applied to the case 30 can be more effectively reduced.

[0064] In addition, in this embodiment and the third and fourth modified examples, the P terminal 40, 340, 440, which is an example of a main terminal, has folded portions 43, 343, 443 bent from the periphery of the fastened portion 41, 341, 441 at both ends of the fastened portion 41, 341, 441 in the width direction (X direction) of the P terminal 40, 340, 440 that intersects with the extension direction (Y direction) of the extending portion 42, 342, 442.

[0065] This allows the nut N to be sandwiched between the pair of opposing fastened portions 41, 341, 441, so that the torque applied to the case 30 can be reduced more reliably.

[0066] In the first, second and fifth modified examples of this embodiment, the extending portion 142, 242, 542 is bent and extends from the fastened portion 141, 241, 541, and abuts against the nut N. The bent portion 143, 243, 543 is bent from the periphery of the end portion of the fastened portion 141, 241, 541 opposite to the extending portion 142, 242, 542.

[0067] This allows the nut N to be sandwiched between the bent portion 143, 243, 543 and the extended portion 142, 242, 542, so that the torque applied to the case 30 can be reduced more reliably.

[0068] In the present embodiment and the first modified example, the bent portions 43, 143 come into contact with the side surface Na of the nut N and are formed larger than the side surface Na of the nut N.

[0069] This increases the contact area between the bent portions 43, 143 and the wall surfaces of the recessed portion 32, and allows the bent portions 43, 143 to disperse the torque applied from the nut N. This makes it possible to more reliably prevent damage to the case 30. Furthermore, the increased contact area between the bent portions 43, 143 and the wall surfaces of the recessed portion 32 improves heat dissipation.

[0070] In the second and third modified examples of this embodiment, the bent portions 243, 343 have openings 243a, 343a through which the corners of the nut N are exposed.

[0071] This allows the material used for the openings 243a, 343a to be reduced, and the bent portions 243, 343 approach the fastening holes 241a, 341a to reduce the size of the fastened portions 241, 341, thereby reducing the material used for the fastened portions 241, 341. This allows costs to be reduced. In addition, the P terminals 240, 340 can be made smaller as the fastened portions 241, 341 are made smaller. Furthermore, if the P terminals 240, 340 abut against the nut N at the openings 243a, 343a, the nut N can be held more reliably, and the torque applied to the case 30 can be more reliably reduced.

[0072] In the second modification of this embodiment, the extension portion 242 has an opening 242a through which a corner of the nut N is exposed.

[0073] This allows the material used for opening 242a to be reduced, and also allows the material used for fastened portion 241 to be reduced by making fastened portion 241 smaller as extension portion 242 approaches fastening hole 241a. This allows costs to be reduced. Also, the P terminal 240 can be made smaller as the fastened portion 241 is made smaller. Furthermore, if P terminal 240 abuts against nut N at opening 242a, nut N can be held more reliably, and the torque applied to case 30 can be more reliably reduced.

[0074] In the present embodiment (and the first to fifth modifications), the bent portion 43 abuts against the wall surface of the recess 32 of the case 30.

[0075] As a result, even if the nut N tries to rotate, the bent portion 43 that enters between the wall surface of the recess 32 and the nut N can receive torque from the nut N in a stable state. Therefore, damage to the case 30 can be more reliably suppressed.

[0076] The invention as described in the claims of the original application is set forth below.

[0077] <Appendix 1> A semiconductor element; a main terminal including a fastening portion including a fastening hole and fastened to an external conductor by a screw and a nut in the fastening hole, and an extension portion extending from the fastening portion toward the semiconductor element and electrically connected to the semiconductor element; a case for accommodating the semiconductor element; the case has a recess for accommodating the nut, The main terminal further includes a bent portion that is bent from a peripheral edge of the fastened portion that is different from the extending portion side and that enters between a wall surface of the recess in the case and the nut. A semiconductor device comprising:

[0078] <Appendix 2> The main terminal has a bent portion bent from the periphery of the fastened portion at both ends of the fastened portion in a width direction of the main terminal intersecting with an extension direction of the extended portion. 2. The semiconductor device according to claim 1 .

[0079] <Appendix 3> The extension portion is bent and extends from the fastened portion and abuts against the nut, The bent portion is bent from the periphery of the end portion of the fastened portion opposite to the extended portion. 2. The semiconductor device according to claim 1 .

[0080] <Appendix 4> The bent portion abuts against a side surface of the nut and is formed larger than the side surface of the nut. 4. The semiconductor device according to claim 1,

[0081] <Appendix 5> The bent portion has an opening through which a corner of the nut is exposed. 4. The semiconductor device according to claim 1,

[0082] <Appendix 6> The extension has an opening through which a corner of the nut is exposed. 4. The semiconductor device according to claim 3.

[0083] <Appendix 7> The bent portion abuts against the wall surface of the recess. 4. The semiconductor device according to claim 1, [Industrial Applicability]

[0084] INDUSTRIAL APPLICABILITY As described above, the present invention has the effect of reducing the torque applied to a case in a semiconductor device when an outer conductor is fastened to a main terminal, and is useful, for example, in power semiconductor devices. [Explanation of symbols]

[0085] 1 Semiconductor device 10 Unit Module 11. Laminated substrate 11a Insulating plate 11b Heat sink 11c circuit board 12 Semiconductor elements 13 Metal wiring board 20 Metal Base 30 cases 31 Hollow part 32, 33, 34 Recess 32a, 34a Nut receiving section 32b, 34b Screw receiving section 35 Through hole 40,140,240,340,440,540 P terminal 50N terminal 60M terminal 41,51,61,141,241,341,441,541 Fastened part 41a,51a,61a,141a,241a,341a,441a,541a Fastening hole 42,52,62,142,242,342,442,542 Stretched part 242a aperture 43,63,143,243,343,443,543 Bending part 243a,343a opening 444,544 Folding part C1, C2, C3 Outer conductor J1,J2 Bonding material N Nut Na Side S Screw

Claims

1. A semiconductor element; a main terminal including a fastening portion including a fastening hole and fastened to an external conductor by a screw and a nut in the fastening hole, and an extension portion extending from the fastening portion toward the semiconductor element and electrically connected to the semiconductor element; a case for accommodating the semiconductor element; the case has a recess for accommodating the nut, The main terminal further includes a bent portion that is bent from a peripheral edge of the fastened portion that is different from the extending portion side and that enters between a wall surface of the recess in the case and the nut. A semiconductor device comprising:

2. The main terminal has a bent portion bent from the periphery of the fastened portion at both ends of the fastened portion in a width direction of the main terminal intersecting with an extension direction of the extended portion.

2. The semiconductor device according to claim 1.

3. The extension portion is bent and extends from the fastened portion and abuts against the nut, The bent portion is bent from the periphery of the end portion of the fastened portion opposite to the extended portion.

2. The semiconductor device according to claim 1.

4. The bent portion abuts against a side surface of the nut and is formed larger than the side surface of the nut.

4. The semiconductor device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

5. The bent portion has an opening through which a corner of the nut is exposed.

4. The semiconductor device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

6. The extension has an opening through which a corner of the nut is exposed.

4. The semiconductor device according to claim 3.

7. The bent portion abuts against the wall surface of the recess.

4. The semiconductor device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

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