Semiconductor modules, methods for manufacturing semiconductor modules, and power conversion devices

Abstract

The semiconductor module (100, 100A, 100B, 100C) comprises: a finned substrate (10) having a first surface (10a) and a second surface (10b) opposite to the first surface; an insulating sheet (30) disposed on the first surface; a plurality of frame patterns (41) disposed on the first surface with respect to the insulating sheet; a semiconductor element (50) disposed on at least one of the plurality of frame patterns; and a plurality of fins (20) clamped to the second surface in a manner that separates them from each other in a first direction (DR1). The second surface is formed with: a plurality of vertical wall portions (11) extending along a second direction (DR2) intersecting the first direction and separated from each other in the first direction; and a plurality of clamping portions (12) extending along the second direction between each of the plurality of vertical wall portions.

Description

Technical Field

[0001] This disclosure relates to semiconductor modules, methods for manufacturing semiconductor modules, and power conversion devices. Background Technology

[0002] International Publication No. 2015 / 046040 (Patent Document 1) discloses a power module with an integrated heat sink. The power module with an integrated heat sink described in Patent Document 1 has a finned substrate, a first fin and a second fin, an insulating sheet, a lead frame, a power semiconductor element and a molding resin.

[0003] The finned substrate has a first surface and a second surface opposite to the first surface. An insulating sheet is disposed on the first surface. A portion of a lead frame (hereinafter, the portion of the lead frame disposed on the first surface is referred to as the frame pattern) is disposed on the insulating sheet. A power semiconductor element is disposed on the frame pattern. The lead frame includes external terminals.

[0004] A first fin insertion groove and a second fin insertion groove are formed on the second surface. The first fin insertion groove and the second fin insertion groove extend along a first direction and are separated from each other in a second direction perpendicular to the first direction. A clamping portion is formed between the first fin insertion groove and the second fin insertion groove. A groove (hereinafter referred to as "clamping groove") extending along the first direction is formed on the upper surface of the clamping portion.

[0005] The first and second fins are clamped together by a clamping part. The molding resin seals the fin substrate, lead frame, insulating sheet, and power semiconductor element with the external terminals and the second surface exposed from the molding resin.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2015 / 046040 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] By inserting the auxiliary tool into the clamping groove, the clamping part undergoes plastic deformation, and the width of the clamping groove expands along the second direction. As a result, the first fin and the second fin are clamped together by the clamping part.

[0011] Due to the thermal shrinkage of the molding resin, the integrated power module of the heat sink described in Patent Document 1 is warped into a convex shape along the direction from the first surface to the second surface before the first fin and the second fin are installed.

[0012] Due to the load when the auxiliary tool is inserted into the groove, the aforementioned warping is forcibly flattened. At this time, due to the bending stress accompanying the flattening of the warping, there is a concern about peeling between the ends of the frame pattern and the insulating sheet or cracks in the insulating sheet. Due to the peeling of the insulating sheet and cracks in the insulating sheet, the insulation of the heat sink integrated power module described in Patent Document 1 is reduced.

[0013] This disclosure was made in view of the problems of the prior art described above. More specifically, this disclosure provides a semiconductor module capable of suppressing the reduction in insulation caused by the peeling of the insulating sheet or the formation of cracks in the insulating sheet.

[0014] Methods for solving problems

[0015] The semiconductor module disclosed herein comprises: a finned substrate having a first surface and a second surface opposite to the first surface; an insulating sheet disposed on the first surface; a plurality of frame patterns disposed on the first surface with respect to the insulating sheet; a semiconductor element disposed on at least one of the plurality of frame patterns; and a plurality of fins clamped to the second surface in a manner that separates them from each other in a first direction. The second surface is formed with: a plurality of vertical wall portions extending along a second direction intersecting the first direction and separated from each other in the first direction; and a plurality of clamping portions extending along the second direction between each of the plurality of vertical wall portions. At least one of the plurality of clamping portions includes: a contact portion contacting each of the plurality of fins; and a separation portion separating from each of the plurality of fins.

[0016] Invention Effects

[0017] The semiconductor module disclosed herein can suppress the reduction in insulation caused by peeling of the insulating sheet or the generation of cracks in the insulating sheet. Attached Figure Description

[0018] Figure 1 This is a top view of semiconductor module 100.

[0019] Figure 2 yes Figure 1 Sectional view at point II-II.

[0020] Figure 3 This is a bottom view of semiconductor module 100.

[0021] Figure 4 yes Figure 3 A cross-sectional view at point IV-IV.

[0022] Figure 5 It is a cross-sectional view of the frame pattern 41 near the end.

[0023] Figure 6 This is a process diagram illustrating the manufacturing method of the semiconductor module 100.

[0024] Figure 7 This is a schematic cross-sectional view used to illustrate the chiseling and tightening process S5.

[0025] Figure 8 It is a cross-sectional view of the chisel blade 200 parallel to the second direction DR2.

[0026] Figure 9 This is a bottom view of semiconductor module 100A.

[0027] Figure 10 This is a top view of semiconductor module 100B.

[0028] Figure 11 yes Figure 10 A cross-sectional view at XI-XI.

[0029] Figure 12 This is a top view of semiconductor module 100C.

[0030] Figure 13 yes Figure 12 A cross-sectional view at point XIII-XIII.

[0031] Figure 14 This is a block diagram showing the structure of the power conversion system 300. Detailed Implementation

[0032] The embodiments of this disclosure will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts are labeled with the same reference numerals, and the description will not be repeated.

[0033] Implementation Method 1

[0034] The semiconductor module of Embodiment 1 (hereinafter referred to as "semiconductor module 100") will be described below.

[0035] <Structure of Semiconductor Module 100>

[0036] Figure 1 This is a top view of semiconductor module 100. Figure 1 The semiconductor element 50, lead 60, and molding resin 80 are omitted from the illustration. Figure 2 yes Figure 1 Sectional view at point II-II. Figure 3 This is a bottom view of the semiconductor module 100. Figure 3 In the diagram, frame patterns 41a and 41b are represented by dashed lines. Figure 4 yes Figure 3 A cross-sectional view at point IV-IV.

[0037] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, the semiconductor module 100 has a finned substrate 10, a plurality of fins 20, an insulating sheet 30, a lead frame 40, a semiconductor element 50, a lead 60, a panel 70, and a molding resin 80.

[0038] The finned substrate 10 has a first surface 10a and a second surface 10b. The first surface 10a and the second surface 10b are the end faces of the finned substrate 10 in the thickness direction. The second surface 10b is the opposite surface of the first surface 10a. The finned substrate 10 is formed of, for example, a metallic material. This metallic material is aluminum, aluminum alloy, copper, copper alloy, etc. The finned substrate 10 has a rectangular shape when viewed from above (from a direction perpendicular to the first surface 10a).

[0039] The first surface 10a has a first end 10aa and a second end 10ab in a first direction DR1. The second end 10ab is the end opposite to the first end 10aa. The first direction DR1 is along the length direction of the fin base 10.

[0040] A plurality of upright wall portions 11 and a plurality of clamping portions 12 are formed on the second surface 10b. The upright wall portions 11 extend along a second direction DR2. The second direction DR2 is a direction that intersects (preferably perpendicular to) the first direction DR1. The plurality of upright wall portions 11 are separated from each other in the first direction DR1. The upright wall portions 11 stand upright from the second surface 10b along a direction from the first surface 10a toward the second surface 10b.

[0041] Multiple clamping portions 12 extend along a second direction DR2 between two adjacent upright wall portions 11. The clamping portions 12 stand upright from the second surface 10b along a direction from the first surface 10a toward the second surface 10b. A groove 12a is formed on the upper surface of the clamping portion 12. The groove 12a extends along the second direction DR2. Details regarding the clamping portions 12 will be described later.

[0042] The fins 20 have a flat plate shape. The thickness direction of the fins 20 is along a first direction DR1. Multiple fins 20 are spaced apart and adjacent to each other along the first direction DR1. The fins 20 extend along a second direction DR2 when viewed from above. The fins 20 are formed, for example, of a metallic material. This metallic material is aluminum, aluminum alloy, copper, copper alloy, etc. The fins 20 are disposed between adjacent vertical wall portions 11 and clamping portions 12.

[0043] When viewed from above, the fin 20 extends from the outer edge of the fin base 10 at both ends in the second direction DR2. However, when viewed from above, the fin 20 is located inside the outer edge of the panel 70.

[0044] An insulating sheet 30 is disposed on the first surface 10a. The insulating sheet 30 is formed of an insulating material. The insulating material is, for example, a resin material.

[0045] The lead frame 40 is formed of a metallic material, such as aluminum, aluminum alloy, copper, or copper alloy. The lead frame 40 has a frame pattern 41 and a terminal portion 42. The frame pattern 41 is disposed on the first surface 10a with an insulating sheet 30 in between. The terminal portion 42 is for connection to an external device. The frame pattern 41 is located closer to the first surface 10a than the terminal portion 42. That is, a step is formed between the frame pattern 41 and the terminal portion 42.

[0046] The frame pattern 41 disposed on the central portion of the first surface 10a is designated as frame pattern 41a and frame pattern 41b. Frame pattern 41a and frame pattern 41b extend along the first direction DR1. Frame pattern 41a and frame pattern 41b are disposed adjacent to each other in the second direction DR2 with a gap between them. This gap is preferably larger than the thickness of frame pattern 41a (frame pattern 41b).

[0047] The fin 20 closest to the first end 10aa is designated as fin 20a. The fin 20 closest to the second end 10ab is designated as fin 20b. The two ends of the frame pattern 41a and frame pattern 41b in the first direction DR1 are located outside the fins 20a and 20b, respectively. That is, the ends of the frame pattern 41a and frame pattern 41b on the first end 10aa side are closer to the first end 10aa than the fin 20a, and the ends of the frame pattern 41a and frame pattern 41b on the second end 10ab side are closer to the second end 10ab than the fin 20b.

[0048] The frame pattern 41 has a portion located further outward than the vertical wall portion 11 (tightening portion 12) on the side closest to the first end 10aa and the vertical wall portion 11 (tightening portion 12) on the side closest to the second end 10ab. The frame pattern 41 may also be located further inward than the vertical wall portion 11 (tightening portion 12) on the side closest to the first end 10aa and the vertical wall portion 11 (tightening portion 12) on the side closest to the second end 10ab.

[0049] Figure 5 This is a cross-sectional view of frame pattern 41 near the end. (See image) Figure 5 As shown, the frame pattern 41 has a first surface 41c, a second surface 41d, and a side surface 41e. The first surface 41c and the second surface 41d are end faces of the frame pattern 41 in the thickness direction. The first surface 41c is the surface on the semiconductor element 50 side. The second surface 41d is the opposite surface of the first surface 41c and is the surface on the insulating sheet 30 side. The side surface 41e is connected to the first surface 41c and the second surface 41d. The intersection line of the second surface 41d and the side surface 41e is defined as a corner 41f. The corner 41f is preferably formed by a curved surface.

[0050] Semiconductor element 50 is formed on a semiconductor substrate. The semiconductor substrate is formed of silicon or a material with a wider bandgap than silicon (e.g., silicon carbide, gallium nitride, diamond, etc.). Semiconductor element 50 is disposed on a frame pattern 41. The connection between semiconductor element 50 and frame pattern 41 is made, for example, by soldering (not shown).

[0051] Semiconductor element 50 is a switching element such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor). Semiconductor element 50 can also be a rectifier element such as a Schottky barrier diode or a fast recovery diode. That is, semiconductor element 50 is a power semiconductor element. Semiconductor element 50 can also be a control element used to control the aforementioned power semiconductor element.

[0052] Leads 60 connect multiple frame patterns 41. Thus, multiple semiconductor elements 50 are electrically connected to each other. Leads 60 are formed, for example, of a metallic material. This metallic material is aluminum, aluminum alloy, copper, copper alloy, gold, etc.

[0053] The panel 70 has a flat plate shape. The panel 70 is mounted on the side of the fin 20 of the fin base 10, surrounding the fin base 10. A hole 71 is formed in the panel 70. The hole 71 extends through the panel 70 along its thickness direction. The semiconductor module 100 is fixed to the housing by passing a screw or other fixing component (not shown) through the hole 71 and screwing it into the housing of other devices (not shown). Thus, an airflow path is formed by the housing and the panel 70, allowing air from an air-cooling fan to flow through the airflow path, thereby enabling air cooling of the fin 20.

[0054] The molding resin 80 is formed of an insulating resin material. This insulating resin material is, for example, a thermosetting resin such as epoxy resin. It can also be a thermoplastic resin with high hardness, such as polyphenylene sulfide. The molding resin 80 seals the fin substrate 10, insulating sheet 30, lead frame 40, semiconductor element 50, and lead wire 60 with the second surface 10b and terminal portion 42 exposed.

[0055] <Details of the chisel-tightening part 12>

[0056] The clamping portion 12 has a contact portion 12b and a separating portion 12c. The contact portion 12b is the part that contacts the fin 20. The separating portion 12c is the part that separates from the fin 20. From another perspective, the contact portion 12b is the plastically deformed portion, and the separating portion 12c is the non-plastically deformed portion. That is, the fin 20 is clamped between the contact portion 12b and the vertical wall portion 11, but the fin 20 is not clamped between the separating portion 12c and the vertical wall portion 11.

[0057] Viewed from above, the separating portion 12c is located at a position overlapping the gap between the frame patterns 41a and 41b. The length of the contact portion 12b in the second direction DR2 is defined as a first length, and the length of the separating portion 12c in the second direction DR2 is defined as a second length. The value obtained by dividing the second length by the first length is preferably 0.3 or more and 0.6 or less. Figures 1-4 In the example shown, the contact portion 12b and the separation portion 12c are formed as one unit, but the contact portion 12b and the separation portion 12c can also be separated from each other.

[0058] <Manufacturing Method of Semiconductor Module 100A>

[0059] Figure 6 This is a process diagram illustrating the manufacturing method of the semiconductor module 100. (Example) Figure 6 As shown, the manufacturing method of semiconductor module 100 includes a semiconductor element mounting process S1, a wire bonding process S2, a molding process S3, a panel mounting process S4, and a clamping process S5.

[0060] In the semiconductor device mounting process S1, firstly, solder is placed on the frame pattern 41. Secondly, with the semiconductor device 50 placed on the solder, the solder is heated and melted. After cooling, the connection between the semiconductor device 50 and the frame pattern 41 is achieved through the solder. In the wire bonding process S2, wires 60 are used to perform wire bonding between adjacent frame patterns 41.

[0061] In molding process S3, molding resin 80 is formed. The molding resin 80 is formed, for example, by a transfer mold. More specifically, first, the semiconductor module 100, which has completed the wire bonding process S2, is disposed together with a fin substrate 10 having an insulating sheet 30 on its first surface 10a within a mold. Second, resin material is filled into the mold, and the resin material is cured.

[0062] Furthermore, due to the thermal shrinkage of the molding resin 80 after the semiconductor module 100 is removed from the mold, the upper surface of the molding resin 80 of the semiconductor module 100 may warp downwards into a convex shape (protruding from the first surface 10a toward the second surface 10b). However, in the semiconductor module 100, the direction of this warping is irrelevant, and the same effect can be obtained.

[0063] In panel installation step S4, panel 70 is fixed by chiseling on the surface of fin 20 side of fin base 10.

[0064] In the tightening process S5, the fins 20 are tightened toward the first surface 10a. In the tightening process S5, firstly, the fins 20 are positioned between the vertical wall portion 11 and the tightening portion 12. Figure 7This is a schematic cross-sectional view used to illustrate the tightening process S5. For example... Figure 7 As shown, in the chiseling process S5, the second step is to chisel the fin 20 through the vertical wall portion 11 and the chiseling portion 12.

[0065] The chiseling is done using a chiseling blade 200. Figure 8 This is a cross-sectional view of the chisel blade 200 parallel to the second direction DR2. (See image.) Figure 8 As shown, the chisel blade 200 has a front end 210. The front end 210 has a first portion 211 and a second portion 212. The width of the first portion 211 in the first direction DR1 is greater than the width of the groove 12a in the first direction DR1. The width of the second portion 212 in the first direction DR1 is smaller than the width of the groove 12a in the first direction DR1. Figure 8 In the example, since the second part 212 becomes a cut, the width of the second part 212 in the first direction DR1 is 0, which is smaller than the width of the groove 12a in the first direction DR1.

[0066] The front end 210 is inserted into the groove 12a. As described above, since the width of the first part 211 in the first direction DR1 is larger than the width of the groove 12a in the first direction DR1, the portion into which the first part 211 is inserted undergoes plastic deformation toward the fin 20 side, thus tightening the fin 20. That is, the portion into which the first part 211 is inserted becomes the contact part 12b.

[0067] On the other hand, the width of the second part 212 in the first direction DR1 is larger than the width of the groove 12a in the first direction DR1, so the portion into which the second part 212 is inserted will not deform toward the fin 20 side. That is, the portion into which the second part 212 is inserted becomes the separation part 12c.

[0068] When the front end 210 is inserted into the groove 12a, a load from the punch 220 is applied to the semiconductor module 100 from the molding resin 80 side in a direction opposite to the insertion direction of the front end 210. This load flattens the warpage of the molding resin 80.

[0069] <Effects of Semiconductor Module 100>

[0070] As described above, warping occurs in the semiconductor module 100 before the fins 20 are tightened due to the heating and shrinkage of the molding resin 80. This warping is flattened by the load from the tightening blade 200 and the punch 220 when the fins 20 are tightened onto the second surface 10b. Due to the bending stress during this flattening, there is concern about delamination between the ends of the frame pattern 41 and the insulating sheet 30 or cracks in the insulating sheet 30.

[0071] However, in the semiconductor module 100, since the clamping portion 12 has a separation portion 12c (the front end 210 has a second portion 212), even if the load from the clamping blade 200 and the punch 220 is small, the surface pressure required to plastically deform the contact portion 12b can be ensured. Therefore, according to the semiconductor module 100, the bending stress generated during the planarization process described above is reduced, and the reduction in insulation caused by peeling between the end of the frame pattern 41 and the insulating sheet 30 or the generation of cracks in the insulating sheet 30 is suppressed.

[0072] The bending stress generated during the planarization process described above acts significantly on frame patterns 41a and 41b. When frame patterns 41a and 41b are arranged with a gap in the second direction DR2, and the separation portion 12c is located at a position overlapping the gap when viewed from above, it is possible to suppress the peeling of the insulating sheet 30 or the generation of cracks in the insulating sheet 30 at locations where stress concentration is likely to occur.

[0073] When the value obtained by dividing the second length by the first length is 0.3 or more and 0.6 or less, it is possible to sufficiently ensure the clamping force on the fin 20 and suppress the reduction in insulation caused by peeling of the insulating sheet 30 or the generation of cracks in the insulating sheet 30.

[0074] When the contact portion 12b and the separating portion 12c are formed separately from each other, the load during the clamping of the fin 20 can be further reduced because the contact portion 12b is easily plastically deformed. As a result, the reduction in insulation caused by peeling of the insulating sheet 30 or the generation of cracks in the insulating sheet 30 can be further suppressed.

[0075] Implementation Method 2

[0076] The semiconductor module of Embodiment 2 (hereinafter referred to as "semiconductor module 100A") will be described below. Here, the differences from semiconductor module 100 will be mainly described, and repeated descriptions will not be given.

[0077] <Structure of Semiconductor Module 100A>

[0078] Semiconductor module 100A has a finned substrate 10, multiple fins 20, an insulating sheet 30, a lead frame 40, semiconductor elements 50, leads 60, a panel 70, and molding resin 80. In this respect, the structure of semiconductor module 100A is the same as that of semiconductor module 100.

[0079] Figure 9 This is a bottom view of semiconductor module 100A. (Example) Figure 9As shown, in semiconductor module 100A, the clamping portion 12 adjacent to fin 20a and the clamping portion 12 adjacent to fin 20b are composed only of contact portion 12b (without separation portion 12c). The clamping portion 12 that is not adjacent to either fin 20a or fin 20b has both contact portion 12b and separation portion 12c. In these respects, the structure of semiconductor module 100A differs from that of semiconductor module 100.

[0080] <Manufacturing Method of Semiconductor Module 100A>

[0081] The manufacturing method of semiconductor module 100A includes a semiconductor element mounting process S1, a wire bonding process S2, a molding process S3, a panel mounting process S4, and a clamping process S5. In this respect, the manufacturing method of semiconductor module 100A is the same as that of semiconductor module 100.

[0082] Insert into the groove 12a of the clamping part 12 that is not adjacent to fins 20a and 20b. Figure 8 The front end 210 of the structure shown. On the other hand, the front end 210 inserted into the groove 12a of the clamping portion 12 adjacent to fin 20a and the groove 12a of the clamping portion 12 adjacent to fin 20b does not have a second portion 212. As a result, the clamping portion 12 adjacent to fin 20a and the clamping portion 12 adjacent to fin 20b do not have a separation portion 12c. Regarding these points, the manufacturing method of semiconductor module 100A differs from the manufacturing method of semiconductor module 100.

[0083] <Effects of Semiconductor Module 100A>

[0084] Fins 20a and 20b are the outermost fins 20 in the first direction DR1, therefore, the fixing force may decrease due to impact. In the semiconductor module 100A, the clamping portion 12 adjacent to fin 20a and the clamping portion 12 adjacent to fin 20b do not have a separation portion 12c, and the contact area between the clamping portion 12 and the fin 20 is increased, thus improving the resistance to external forces.

[0085] Implementation Method 3

[0086] The semiconductor module of Embodiment 3 (hereinafter referred to as "semiconductor module 100B") will be described below. Here, the differences from semiconductor module 100 will be mainly described, and repeated descriptions will not be repeated.

[0087] Semiconductor module 100B has a finned substrate 10, multiple fins 20, an insulating sheet 30, a lead frame 40, semiconductor elements 50, leads 60, a panel 70, and molding resin 80. In this respect, the structure of semiconductor module 100B is the same as that of semiconductor module 100.

[0088] Figure 10 This is a top view of semiconductor module 100B. Figure 10 The semiconductor element 50, lead 60, and molding resin 80 are omitted from the illustration. Figure 11 yes Figure 10 A cross-sectional view at XI-XI. (See figure) Figure 10 and Figure 11 As shown, frame pattern 41a is divided into a first segmented frame pattern 41aa and a second segmented frame pattern 41ab in the first direction DR1. Frame pattern 41b is divided into a first segmented frame pattern 41ba and a second segmented frame pattern 41bb in the first direction DR1.

[0089] The division of frame pattern 41a is performed on the central portion of frame pattern 41a in the first direction DR1. The division of frame pattern 41b is performed on the central portion of frame pattern 41b in the first direction DR1.

[0090] The first segmented frame pattern 41aa and the second segmented frame pattern 41ab are connected by a lead wire 61. The first segmented frame pattern 41ba and the second segmented frame pattern 41bb are connected by a lead wire 62. Lead wires 61 and 62 are, for example, formed of a metallic material. This metallic material is aluminum, aluminum alloy, copper, copper alloy, gold, etc.

[0091] When viewed from above, lead wire 61 overlaps with the separating portion 12c. When viewed from above, lead wire 62 overlaps with the contact portion 12b. To reduce the amount of molding resin 80, the arc height of lead wires 61 and 62 is preferably as low as possible. The shapes of lead wires 61 and 62 are, for example, circular or strip-shaped.

[0092] The first dividing frame pattern 41aa and the second dividing frame pattern 41ab are arranged with a gap between them in the first direction DR1. The lead wire 61 passes over this gap when viewed from above. The first dividing frame pattern 41ba and the second dividing frame pattern 41bb are arranged with a gap between them in the first direction DR1. The lead wire 62 passes over this gap when viewed from above.

[0093] The first segmented frame pattern 41aa and the second segmented frame pattern 41ab function electrically the same as the unsegmented frame pattern 41a, and the first segmented frame pattern 41ba and the second segmented frame pattern 41bb function electrically the same as the unsegmented frame pattern 41b. Regarding these points, the structure of semiconductor module 100B differs from that of semiconductor module 100.

[0094] <Manufacturing Method of Semiconductor Module 100B>

[0095] The manufacturing method of semiconductor module 100A includes a semiconductor element mounting process S1, a wire bonding process S2, a molding process S3, a panel mounting process S4, and a clamping process S5. In this respect, the manufacturing method of semiconductor module 100A is the same as that of semiconductor module 100.

[0096] In the manufacturing method of semiconductor module 100B, in the wire bonding process S2, not only is wire bonding of lead 60 performed, but also wire bonding of leads 61 and 62 is performed. In this respect, the manufacturing method of semiconductor module 100B differs from the manufacturing method of semiconductor module 100.

[0097] <Effects of Semiconductor Module 100B>

[0098] In the semiconductor module 100B, since the frame pattern 41a (frame pattern 41b) is segmented, the warping caused by thermal shrinkage of the molding resin 80 is flattened during clamping, and the stress generated at the ends of the frame pattern 41a is further reduced. Therefore, according to the semiconductor module 100B, the reduction in insulation caused by peeling of the insulating sheet 30 or the generation of cracks in the insulating sheet 30 is further suppressed.

[0099] Implementation Method 4

[0100] The semiconductor module of Embodiment 4 (hereinafter referred to as "semiconductor module 100C") will be described below. Here, the differences from semiconductor module 100 will be mainly described, and repeated descriptions will not be given.

[0101] Semiconductor module 100C has a finned substrate 10, multiple fins 20, an insulating sheet 30, a lead frame 40, semiconductor elements 50, leads 60, a panel 70, and molding resin 80. In this respect, the structure of semiconductor module 100C is the same as that of semiconductor module 100.

[0102] Figure 12 This is a top view of semiconductor module 100C. Figure 12 The semiconductor element 50, lead 60, and molding resin 80 are omitted from the illustration. Figure 13 yes Figure 12 A sectional view at point XIII-XIII. (See attached image.) Figure 12 and Figure 13As shown, the frame pattern 41a has a first portion 41ac, a second portion 41ad, and a step portion 41ae. The first portion 41ac and the second portion 41ad are arranged along a first direction DR1. The step portion 41ae connects the first portion 41ac and the second portion 41ad. The step portion 41ae protrudes toward the side opposite to the first surface 10a. That is, in the frame pattern 41a, a step is formed in the step portion 41ae at a distance greater than that of the first portion 41ac and the second portion 41ad.

[0103] Similarly, the frame pattern 41b has a first portion 41bc, a second portion 41bd, and a step portion 41be. The first portion 41bc and the second portion 41bd are arranged along a first direction DR1. The step portion 41be connects the first portion 41bc and the second portion 41bd. The step portion 41be protrudes towards the side opposite to the first surface 10a. That is, in the frame pattern 41b, a step is formed in the step portion 41be at a distance greater than that of the first portion 41bc and the second portion 41bd from the first surface 10a. Regarding these points, the structure of the semiconductor module 100C differs from that of the semiconductor module 100.

[0104] <Manufacturing Method of Semiconductor Module 100C>

[0105] The manufacturing method of semiconductor module 100C is the same as that of semiconductor module 100, therefore, the description of the manufacturing method of semiconductor module 100C is omitted.

[0106] <Effects of Semiconductor Module 100C>

[0107] In the semiconductor module 100C, the frame pattern 41a (frame pattern 41b) is prone to deformation at the step portion 41ae (step portion 41be). As the warping caused by the thermal shrinkage of the molding resin 80 is flattened during the tightening process, the stress generated at the end of the frame pattern 41a is further reduced, thus further suppressing the reduction in insulation caused by the peeling of the insulating sheet 30 or the generation of cracks in the insulating sheet 30.

[0108] Implementation Method 5

[0109] This embodiment applies the semiconductor modules of Embodiments 1 to 4 described above to a power conversion device. This disclosure is not limited to a specific power conversion device; hereinafter, Embodiment 5 will describe the application of this disclosure to a three-phase inverter. Hereinafter, the power conversion system of Embodiment 5 will be referred to as "Power Conversion System 300".

[0110] Figure 14 This is a block diagram showing the structure of the power conversion system 300.

[0111] Figure 14 The power conversion system shown is configured to include a power source 400, a power conversion device 500, and a load 600. The power source 400 is a DC power source that supplies DC power to the power conversion device 500. The power source 400 can be composed of various power sources, such as a DC system, solar cells, or batteries, or it can be composed of a rectifier circuit or an AC / DC converter connected to an AC system. Alternatively, the power source 400 can also be configured by a DC / DC converter that converts DC power output from a DC system into a specified power.

[0112] The power conversion device 500 is a three-phase inverter connected between the power source 400 and the load 600, which converts the DC power supplied from the power source 400 into AC power and supplies AC power to the load 600. Figure 14 As shown, the power conversion device 500 includes: a main conversion circuit 501 that converts DC power into AC power and outputs it; and a control circuit 503 that outputs a control signal to the main conversion circuit 501.

[0113] Load 600 is a three-phase motor driven by AC power supplied from power conversion device 500. Furthermore, load 600 is not limited to a specific application; it is a motor mounted on various electrical equipment, such as motors used in hybrid vehicles, electric vehicles, railway vehicles, elevators, or air conditioning equipment.

[0114] The power conversion device 500 will now be described in detail. The main conversion circuit 501 includes switching elements and freewheeling diodes (not shown). By switching the switching elements, it converts the DC power supplied from the power source 400 into AC power and supplies it to the load 600. The main conversion circuit 501 has various specific circuit structures, but in this embodiment, it is a two-level three-phase full-bridge circuit, which can be composed of six switching elements and six freewheeling diodes connected in anti-parallel to each switching element. At least one of the switching elements and freewheeling diodes in the main conversion circuit 501 is a switching element or freewheeling diode found in a semiconductor module 502, equivalent to the semiconductor module in any of embodiments 1 to 4 described above. The six switching elements are connected in series in pairs to form upper and lower arms, and each upper and lower arm constitutes a phase (U phase, V phase, W phase) of the full-bridge circuit. Furthermore, the output terminals of each upper and lower arm, i.e., the three output terminals of the main conversion circuit 501, are connected to the load 600.

[0115] The main conversion circuit 501 includes a drive circuit (not shown) for driving each switching element, but the drive circuit may be integrated into the semiconductor module 502 or it may be separate from the semiconductor module 502. The drive circuit generates drive signals to drive the switching elements of the main conversion circuit 501 and supplies them to the control electrodes of the switching elements of the main conversion circuit 501. Specifically, based on the control signal from the control circuit 503 (described later), drive signals that turn the switching element on and drive signals that turn the switching element off are output to the control electrodes of each switching element. When the switching element is maintained in the on state, the drive signal is a voltage signal above the threshold voltage of the switching element (on signal); when the switching element is maintained in the off state, the drive signal is a voltage signal below the threshold voltage of the switching element (off signal).

[0116] Control circuit 503 controls the switching elements of main conversion circuit 501 to supply the desired power to load 600. Specifically, based on the power to be supplied to load 600, the time (on-time) during which each switching element of main conversion circuit 501 should be in the on state is calculated. For example, main conversion circuit 501 can be controlled by PWM control that modulates the on-time of the switching elements according to the output voltage. Then, control commands (control signals) are output to the drive circuit of main conversion circuit 501, causing an on signal to be output for the switching elements that should be in the on state at each time, and an off signal to be output for the switching elements that should be in the off state. The drive circuit outputs an on or off signal as a drive signal to the control electrode of each switching element according to the control signal.

[0117] In the power conversion device 500, the semiconductor modules described in Embodiments 1 to 4 are used as the semiconductor module 502 constituting the main conversion circuit 501, thereby enabling the suppression of insulation degradation.

[0118] In this embodiment, an example of applying this disclosure to a two-level three-phase inverter has been described, but this disclosure is not limited thereto and can be applied to various power conversion devices. In this embodiment, a two-level power conversion device is used, but it can also be a three-level or multi-level power conversion device. When supplying power to a single-phase load, this disclosure can also be applied to a single-phase inverter. Furthermore, when supplying power to DC loads, etc., this disclosure can also be applied to DC / DC converters or AC / DC converters.

[0119] Furthermore, the power conversion device using this disclosure is not limited to the case where the load is an electric motor. For example, it can also be used as a power supply device for electrical discharge machining or laser processing machines, induction heating cookers, contactless power supply systems, and as a power regulator for solar power generation systems, energy storage systems, etc.

[0120] The embodiments disclosed herein should be considered merely illustrative in all respects and not as limiting. The essential scope of this disclosure is set forth not by the foregoing embodiments but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0121] Label Explanation

[0122] 10: Fin base; 10a: First surface; 10aa: First end; 10ab: Second end; 10b: Second surface; 11: Vertical wall portion; 12: Grate portion; 12a: Groove; 12b: Contact portion; 12c: Separation portion; 20: Fin; 20a: Fin; 20b: Fin; 30: Insulating sheet; 40: Lead frame; 41: Frame pattern; 41a: Frame pattern; 41aa: First segmented frame pattern; 41ab: Second segmented frame pattern; 41ac: First part; 41ad: Second part; 41ae: Step portion; 41b: Frame pattern; 41ba: First segmented frame pattern; 41bb: Second segmented frame pattern; 41bc: First part; 41bd: Second part; 41be: Step portion; 41c: First surface; 41d: Second surface; 41e: Side surface; 41f: Corner; 42: Terminal; 50: Semiconductor element; 60: Lead; 61: Lead; 62: Lead; 70: Panel; 71: Hole; 80: Molding resin; 100: Semiconductor module; 100A: Semiconductor module; 100B: Semiconductor module; 100C: Semiconductor module; 200: Clenching blade; 210: Front end; 211: First part; 212: Second part; 220: Punch; 300: Power conversion system; 400: Power supply; 500: Power conversion device; 501: Main conversion circuit; 502: Semiconductor module; 503: Control circuit; 600: Load; DR1: First direction; DR2: Second direction; S1: Semiconductor element mounting process; S2: Lead bonding process; S3: Molding process; S4: Panel mounting process; S5: Clenching process.

Claims

1. A semiconductor module comprising: A finned substrate having a first surface and a second surface that is the opposite surface to the first surface; An insulating sheet is disposed on the first surface; Multiple frame patterns are arranged on the first surface, separated by the insulating sheet; A semiconductor element disposed on at least one of the plurality of frame patterns; as well as Multiple fins are hewn tightly to the second surface in a manner that separates them from each other in the first direction. The second surface has a plurality of vertical wall portions that extend along a second direction intersecting the first direction and are separated from each other in the first direction; and multiple clamping portions, which extend along the second direction between each of the multiple vertical wall portions. At least one of the plurality of clamping portions includes a contact portion that contacts each of the plurality of fins; and the separation section, which is separated from each of the plurality of fins, The first direction is along the length direction of the fin substrate. The first surface includes a first end and a second end that is the opposite side of the first end in the first direction. The plurality of frame patterns includes a first frame pattern and a second frame pattern, the first frame pattern and the second frame pattern extending along the first direction on the central portion of the first surface and arranged with gaps between them in the second direction. The two ends of the first frame pattern and the second frame pattern are respectively located further outward than the first fin, which is closest to the first end, and the second fin, which is closest to the second end, among the plurality of fins. When viewed from a direction perpendicular to the first surface, the separation portion is located at a position overlapping the gap between the first frame pattern and the second frame pattern.

2. The semiconductor module according to claim 1, wherein, The first and second of the plurality of clamping portions are adjacent to the first and second fins, respectively, and are composed only of the contact portions.

3. The semiconductor module according to claim 1 or 2, wherein, The semiconductor module also has leads. The first frame pattern is divided into a first segmented frame pattern and a second segmented frame pattern in the first direction. The first segmented frame pattern and the second segmented frame pattern are connected by the lead wire.

4. The semiconductor module according to claim 1 or 2, wherein, The first frame pattern has: a first part; a second part; and a stepped part that connects the first part and the second part and protrudes to the side opposite to the first surface.

5. The semiconductor module according to any one of claims 1 to 4, wherein, The length of the contact portion in the second direction, i.e., the first length, is longer than the length of the separation portion in the second direction, i.e., the second length.

6. The semiconductor module according to claim 5, wherein, The value obtained by dividing the second length by the first length is greater than 0.3 and less than 0.

6.

7. A power conversion device comprising: A main conversion circuit having the semiconductor module as described in any one of claims 1 to 6, converting and outputting input power; and The control circuit outputs control signals to the main conversion circuit.

8. A method for manufacturing a semiconductor module, comprising the following steps: Semiconductor elements are disposed on at least one of a plurality of frame patterns; The plurality of frame patterns are configured on the first surface, separated by an insulating sheet located on the first surface of the fin substrate; as well as Multiple fins are chiseled tightly to a second surface, which is the opposite side of the first surface, in a manner that separates them from each other in a first direction. The second surface has a plurality of vertical wall portions that extend along a second direction intersecting the first direction and are separated from each other in the first direction; and multiple clamping portions, which extend along the second direction between each of the multiple vertical wall portions. A groove extending along the second direction is formed on the upper surface of each of the plurality of clamping portions. The process of chiseling the plurality of fins together is performed by widening the groove along the first direction by inserting the tip of a chiseling blade into the groove. The front end includes a first portion whose width in the first direction is greater than that of the groove, and a second portion whose width in the first direction is smaller than that of the groove. At least one of the plurality of clamping portions includes a contact portion that contacts each of the plurality of fins; and the separation section, which is separated from each of the plurality of fins, The first direction is along the length direction of the fin substrate. The first surface includes a first end and a second end that is the opposite side of the first end in the first direction. The plurality of frame patterns includes a first frame pattern and a second frame pattern, the first frame pattern and the second frame pattern extending along the first direction on the central portion of the first surface and arranged with gaps between them in the second direction. The two ends of the first frame pattern and the second frame pattern are respectively located further outward than the first fin, which is closest to the first end, and the second fin, which is closest to the second end, among the plurality of fins. When viewed from a direction perpendicular to the first surface, the separation portion is located at a position overlapping the gap between the first frame pattern and the second frame pattern.

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