Method for manufacturing semiconductor module

Abstract

The invention provides a method for manufacturing a semiconductor module in which a screw can be reliably fastened to a housing. The molding space (61a) is provided with: a molding inner surface (60d2) that defines an outer frame and a storage region; and a molding outer surface (60d1) that is provided outside the molding inner surface (60d2) and in which an injection port (60da) communicating with the molding space (61a) is formed so as to be separated inward from the respective ends thereof in plan view. And a molding bottom surface (60d3) that connects the molding inner surface (60d2) and the molding outer surface (60d1) and is in contact with the lower surface of the outer frame. The mold pin section (62) is disposed at a corner of the molding space (61a) so as to be perpendicular to the molding bottom surface (60d3) in plan view. The rod-shaped second mold member (64) is disposed so as to be parallel to the mold pin section (62) at a location closer to the molding inner surface (60d2) than the molding outer surface (60d1) in plan view in the molding space (61a) during the injection step, between the mold pin section (62) and the injection port (60da).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor module. Background Art

[0002] A semiconductor module includes a housing that houses semiconductor elements and a printed circuit board that is mounted on the upper surface of the housing using self-tapping screws. The housing is made of resin and has mounting holes through which the self-tapping screws for the printed circuit board are inserted. The entire mounting hole has a cylindrical shape, and the front end of the mounting hole is formed in a semi-spherical shape. Thereby, generation of cracks and voids during resin molding of the housing is suppressed (for example, refer to Patent Document 1).

[0003] In addition, a semiconductor device includes an insulating substrate on which a semiconductor chip is disposed, a heat sink on which the insulating substrate is disposed, and a resin housing including a threaded hole that is engaged by a self-tapping screw inserted through a through-hole of the heat sink. A high-voltage-resistant resin is filled in the void of the threaded hole of the resin housing in which the self-tapping screw is engaged, thereby improving the discharge withstand voltage and the dielectric breakdown withstand amount (for example, refer to Patent Document 2).

[0004] Prior Art Documents Patent Documents Patent Document 1: WO 2021 / 024636 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-032392 Summary of the Invention

[0005] Technical Problem The present invention has been made in view of such points, and an object thereof is to provide a method for manufacturing a semiconductor module including a housing in which a screw can be reliably fastened.

[0006] Technical Solution According to one aspect of the present invention, there is provided a method for manufacturing a semiconductor module, comprising: a preparation step of preparing a molding die and a molding material, the molding die having a first die member that forms a cavity corresponding to the shape of a housing, the housing having an outer frame that is rectangular in plan view and surrounds the four sides of a storage area provided from a lid portion to a lower surface, and cylindrical fastening portions for screw fastening are formed at the corners of the upper surface of the outer frame, the first die member having an injection port communicating with the cavity from the outside and including a rod-shaped die pin portion corresponding to the fastening portion; and an injection step of disposing the die pin portion in the cavity of the first die member and injecting the molding material into the cavity from the injection port, the cavity of the first die member including a molding space for molding the outer frame, the molding space being constituted by a molding inner surface that demarcates the outer frame and the storage area, a molding outer surface that is provided outside the molding inner surface and has the injection port communicating with the molding space formed so as to be separated inward from respective ends in plan view, and a molding bottom surface that connects the molding inner surface and the molding outer surface and contacts the lower surface of the outer frame, and the die pin portion is disposed perpendicular to the molding bottom surface at the corners of the molding space in plan view, the molding die further including a rod-shaped second die member that is disposed in a manner parallel to the die pin portion at a position between the die pin portion and the injection port in the molding space in plan view and closer to the molding inner surface than the molding outer surface during the injection step.

[0007] Further, according to one aspect of the present invention, there is provided a method for manufacturing a semiconductor module, including: a preparation step of preparing a molding die and a molding material, the molding die having a first die member that constitutes a cavity corresponding to the shape of a housing, the housing having an outer frame that is rectangular in plan view and surrounds the four sides of a storage area provided from a lid portion to a lower surface, and cylindrical fastening portions for screw fastening formed at the corners of the upper surface of the outer frame, the first die member having an injection port communicating with the cavity from the outside and including a rod-shaped die pin portion corresponding to the fastening portion; and an injection step of disposing the die pin portion in the cavity of the first die member and injecting the molding material into the cavity from the injection port, the cavity of the first die member including a molding space for molding the outer frame, the molding space being composed of a molding inner surface that demarcates the outer frame and the storage area, a molding outer surface provided outside the molding inner surface and having the injection port communicating with the molding space and separating inward from respective ends in plan view, and a molding bottom surface that connects the molding inner surface and the molding outer surface and contacts the lower surface of the outer frame, the die pin portion being disposed perpendicular to the molding bottom surface at the corners of the molding space in plan view, and the injection port being formed on the molding outer surface so as to correspond to a position 30% or less of the height from the upper surface of the outer frame to the lower surface.

[0008] Technical effects According to the disclosed technology, it is possible to provide a method for manufacturing a semiconductor module that can reliably fasten a screw to a housing, can prevent the screw from coming off during operation, and can seek to improve reliability.

[0009] The above description and other objects, features, and advantages of the present invention will become clear from the following description in association with the drawings showing preferred embodiments as examples of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a perspective view of a semiconductor module according to a first embodiment.

[0011] Figure 2 is a cross-sectional view of a semiconductor module according to a first embodiment.

[0012] Figure 3 is a rear view of a semiconductor module according to a first embodiment.

[0013] Figure 4 is a plan view of a semiconductor unit included in a semiconductor module according to a first embodiment.

[0014] Figure 5It is a first cross-sectional view of a semiconductor module with a printed circuit board of the first embodiment installed.

[0015] Figure 6 It is a second cross-sectional view of a semiconductor module with a printed circuit board of the first embodiment installed.

[0016] Figure 7 It is an enlarged cross-sectional view of a semiconductor module with a printed circuit board of the first embodiment installed.

[0017] Figure 8 It is a flowchart showing the manufacturing method of the housing included in the semiconductor module of the first embodiment.

[0018] Figure 9 It is a top view of the molding device of the first embodiment.

[0019] Figure 10 It is a first cross-sectional view of the molding die included in the molding device of the first embodiment.

[0020] Figure 11 It is a second cross-sectional view of the molding die included in the molding device of the first embodiment.

[0021] Figure 12 It is a third cross-sectional view of the molding die included in the molding device of the first embodiment.

[0022] Figure 13 It is a first cross-sectional view showing the injection process included in the manufacturing method of the housing of the comparative example.

[0023] Figure 14 It is an enlarged cross-sectional view of the housing of the comparative example.

[0024] Figure 15 It is a perspective view of the semiconductor module of the second embodiment.

[0025] Figure 16 It is a second cross-sectional view of a semiconductor module with a printed circuit board of the second embodiment installed.

[0026] Figure 17 It is an enlarged cross-sectional view of a semiconductor module with a printed circuit board of the second embodiment installed.

[0027] Figure 18 It is a top view of the molding device of the second embodiment.

[0028] Figure 19 It is a second cross-sectional view of the molding die included in the molding device of the second embodiment.

[0029] Figure 20 It is a third cross-sectional view of the molding die included in the molding device of the second embodiment.

[0030] Symbol Explanation 1, 1a Semiconductor Module 2 Semiconductor Unit 3 Molding Device 4 Molding Die 5, 5a Semiconductor Device 10 Housing 11 Outer Frame 11a~11d Side Wall 11b1, 11b5 Outermost Surface 11b2, 11b4 Inclined Surface 11b3 Outer Surface 11d1, 11d5 Outermost Surface 11d2, 11d4 Inclined Surface 11d3 Outer Surface 11e Upper Surface 11f Lower Surface 11g Step 11h Opening 12 Cover Part 12a Terminal Hole 13 Fastening Part 13a Boss Part 13b Fastening Hole 13c Fastening Surface 13d Fastening Bottom Surface 14 Mounting Part 14a Mounting Hole 15 Storage Area 16 Columnar Mark 20 Insulated Circuit Board 21 Insulated Plate 22 Conductive Pattern 23 Metal Plate 30a, 30b Semiconductor Chip 30c Electronic Component 31 Contact Component 32 External Connection Terminal 33 Conducting Wire 34 Adhesive 35 Encapsulation Component 40 Printed Circuit Board 41 Through-Hole 42 Alignment Hole 50 Self-Tapping Screw 51 Head 52 Threaded Part 60 First Die Component 60a to 60d Side surfaces 60c1, 60d1 Molded outer surfaces 60c2, 60d2 Molded inner surfaces 60c3, 60d3 Molded bottom surfaces 60bc, 60bd, 60da, 60db Injection ports 61 Cavity 61a Molded space 62 Die pin part 62a, 62b Sprue 62c, 62d Runner 63a, 63b, 63c, 63d Gate 64 Second mold part V Gap S Gate mark Detailed implementation mode

[0031] Hereinafter, the embodiments will be described with reference to the drawings. It should be noted that in the following description, "front surface" and "upper surface" represent the X-Y plane facing the upper side (+Z direction) in the semiconductor module in the figure. Similarly, "up" represents the direction of the upper side (+Z direction) in the semiconductor module in the figure. "Back surface" and "lower surface" represent the X-Y plane facing the lower side (-Z direction) in the semiconductor module in the figure. Similarly, "down" represents the direction of the lower side (-Z direction) in the semiconductor module in the figure. The same directionality is also shown in other drawings as needed. "Front surface", "upper surface", "up", "back surface", "lower surface", "down", "side surface" are just expressions for conveniently determining the relative positional relationship, and do not limit the technical idea of the present invention. For example, "up" and "down" do not necessarily refer to the vertical direction relative to the ground. That is, the directions of "up" and "down" are not limited to the direction of gravity. In addition, in the following description, "main component" means a case where it contains 80 vol% or more. In addition, "substantially the same" means within a range of ±10%. In addition, "perpendicular" and "parallel" mean within a range of ±10°. "Up" and "down" do not necessarily refer to the vertical direction relative to the ground. That is, the directions of "up" and "down" are not limited to the direction of gravity. In addition, in the following description, "main component" means a case where it contains 80 vol% or more.

[0032] [First Embodiment] Use Figures 1 to 4 To describe the semiconductor module of the first embodiment. Figure 1 Is a perspective view of the semiconductor module of the first embodiment, Figure 2 Is a cross-sectional view of the semiconductor module of the first embodiment. Figure 3 Is a rear view of the semiconductor module of the first embodiment.Figure 4 It is a top view of the semiconductor unit included in the semiconductor module of the first embodiment. It should be noted that Figure 2 is Figure 1 a cross-sectional view taken along the single-dot chain line Y1 - Y1 of

[0033] The semiconductor module 1 includes a housing 10 and a semiconductor unit 2 housed in the housing 10. A plurality of external connection terminals 32 included in the semiconductor unit 2 extend outward from the front surface of the housing 10. In addition, the inside of the housing 10 is encapsulated by an encapsulation member 35.

[0034] The housing 10 has an outer frame 11 surrounding the periphery of the components constituting the semiconductor module 1 described later, a mounting portion 14 integrally mounted on the outer frame 11, and a lid portion 12 covering the upper portion of the outer frame 11 and integrally mounted on the outer frame 11.

[0035] The outer frame 11 is in the shape of a substantially rectangular box in a top view, and includes a continuous annular upper surface 11e and a lower surface 11f. The upper surface 11e and the lower surface 11f are substantially parallel and substantially smooth. The outer frame 11 includes side walls 11a - 11d surrounding the four sides of the accommodation area 15 (refer to Figure 2 ). The side walls 11a - 11d are integrally connected and are in a continuous annular shape in a top view. It should be noted that the upper surface 11e and the lower surface 11f are constituted by the integrally connected side walls 11a - 11d. The side walls 11a and 11c correspond to the short sides of the outer frame 11 and are parallel to the short side direction (±Y direction) of the outer frame 11. The side walls 11b and 11d correspond to the long sides of the outer frame 11 and are parallel to the long side direction (±X direction) of the outer frame 11.

[0036] The side wall 11b further includes outermost surfaces 11b1, 11b5, an outer surface 11b3, and inclined surfaces 11b2, 11b4. The outermost surfaces 11b1, 11b5 are located at positions more outward (+Y direction) than the outer surface 11b3. That is, the portions of the outermost surfaces 11b1, 11b5 of the side wall 11b are thicker than the portion of the outer surface 11b3. It should be noted that this thick portion (fastening portion) includes a fastening portion 13 described later. In addition, the outermost surfaces 11b1, 11b5 include gate marks S (not shown). The gate marks S will be described later.

[0037] The inclined surfaces 11b2 and 11b4 are provided along the long side direction (±X direction) in the regions where the outermost surfaces 11b1 and 11b5 protrude from the outer surface 11b3. When viewed from the side, the inclined surfaces 11b2 and 11b4 are inclined in such a manner that the upper surface 11e on the side wall 11c and 11a sides of the outer frame 11 described later is lowered toward the center of the side wall 11b. The fastening portion becomes the portion surrounded by the outermost surfaces 11b1, 11b5, the inclined surfaces 11b2, 11b4, the upper surface 11e, and the lower surface 11f.

[0038] The side wall 11d also includes the outermost surfaces 11d1 and 11d5, the outer surface 11d3, and the inclined surfaces 11d2 and 11d4. The outermost surfaces 11d1 and 11d5 are located at positions more outward (-Y direction) than the outer surface 11d3. That is, the portions of the outermost surfaces 11d1 and 11d5 of the side wall 11d are thicker than the portion of the outer surface 11d3. It should be noted that this thick portion (fastening portion) includes the fastening portion 13 described later. In addition, the outermost surfaces 11d1 and 11d5 include the gate marks S. The gate marks S will be described later.

[0039] It should be noted that the thickness of the side walls 11a and 11c is the same as the thickness of the outer surfaces 11b3 and 11d3 of the side walls 11b and 11d, or the thickness of the side walls 11a and 11c is thinner than the thickness of the outer surfaces 11b3 and 11d3 of the side walls 11b and 11d. That is, the thickness of the side walls 11a and 11c is thinner than the thickness of the outermost surfaces 11b1 and 11b5 of the side walls 11b and 11d and the outermost surfaces 11d1 and 11d5.

[0040] The inclined surfaces 11d2 and 11d4 are provided along the long side direction (±X direction) in the regions where the outermost surfaces 11d1 and 11d5 protrude from the outer surface 11d3. When viewed from the side, the inclined surfaces 11d2 and 11d4 are inclined in such a manner that the upper surface 11e on the side wall 11c and 11a sides of the outer frame 11 described later is lowered toward the center of the side wall 11d. The fastening portion becomes the portion surrounded by the outermost surfaces 11d1, 11d5, the inclined surfaces 11d2, 11d4, the upper surface 11e, and the lower surface 11f.

[0041] In addition, when looking down at the upper surface 11e of the side walls 11b and 11d, fastening portions 13 and columnar marks 16 are respectively formed on the side wall 11b and 11d sides closer to the side walls 11a and 11c. It should be noted that the details of the fastening portion 13 and the columnar marks 16 will be described later.

[0042] The mounting portions 14 are integrally formed at the central portions of the side walls 11b and 11d, respectively. The mounting portions 14 are substantially flat plate-shaped and are formed in a plane flush with the lower surface 11f of the outer frame 11 (side walls 11b and 11d). Further, mounting holes 14a may be formed in the mounting portions 14. Such mounting portions 14 may be made of metal, for example. The semiconductor module 1 is disposed in a predetermined installation area, and a screw is inserted through the mounting hole 14a of the mounting portion 14 and fastened at this installation position. Thereby, the semiconductor module 1 can be fixed in this installation area.

[0043] The cover portion 12 covers the upper portion of the accommodation area 15 and is integrally connected to each of the side walls 11a to 11d. The cover portion 12 may not be in the same plane as the upper surfaces 11e of the side walls 11a to 11d, but may be connected to a position lower than the upper surfaces 11e. The cover portion 12 may be formed with terminal holes 12a in a lattice pattern. A plurality of external connection terminals 32 are inserted through the terminal holes 12a of the cover portion 12 and extend vertically upward (+Z direction) from the outer frame 11 with respect to the cover portion 12. Further, the cover portion 12 may be formed with an opening different from the terminal holes 12a. The diameter of this opening may be larger than that of the terminal holes 12a. The encapsulation member 35 can be filled into the housing 10 through this opening.

[0044] Such a housing 10 (except for the mounting portions 14) may be made of a thermoplastic resin. Examples of such a resin include polyphenylene sulfide resin, polybutylene terephthalate resin, polybutylene succinate resin, polyamide resin, or acrylonitrile-butadiene-styrene resin. The housing 10 is formed by injection molding using a thermoplastic resin so as to include the mounting portions 14.

[0045] The semiconductor unit 2 includes an insulating circuit board 20, semiconductor chips 30a and 30b, and a plurality of external connection terminals 32. The insulating circuit board 20 includes an insulating plate 21, a plurality of conductive patterns 22, and a metal plate 23. The insulating plate 21 and the metal plate 23 are rectangular in plan view. Further, the corners of the insulating plate 21 and the metal plate 23 may be R-chamfered or C-chamfered. The size of the metal plate 23 is smaller than that of the insulating plate 21 in plan view, and is formed inside the insulating plate 21.

[0046] The insulating plate 21 has insulating properties and is made of a material having excellent thermal conductivity. Such an insulating plate 21 may be made of ceramic. The ceramic is, for example, alumina, aluminum nitride, or silicon nitride.

[0047] A plurality of conductive patterns 22 are formed on the front surface of the insulating board 21. The plurality of conductive patterns 22 are made of a metal with excellent conductivity. Such a metal is, for example, copper, aluminum, or an alloy mainly composed of at least one of these metals. The surface of the plurality of conductive patterns 22 can be subjected to a plating treatment. At this time, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy. The corrosion resistance of the plurality of conductive patterns 22 after the plating treatment is improved.

[0048] The plurality of conductive patterns 22 are formed on the front surface of the insulating board 21 in the following manner. A metal plate is formed on the front surface of the insulating board 21, and the metal plate is subjected to etching or other processing to obtain a plurality of conductive patterns 22 with a predetermined shape. Alternatively, a plurality of conductive patterns 22 pre-cut from a metal plate can be pressed onto the front surface of the insulating board 21. It should be noted that the plurality of conductive patterns 22 are an example. The number, shape, size, and position of the conductive patterns can be appropriately selected as needed.

[0049] A metal plate 23 is formed on the back surface of the insulating board 21. The metal plate 23 is rectangular. The area of the metal plate 23 when viewed from above is smaller than the area of the insulating board 21 and larger than the area of the region where the plurality of conductive patterns 22 are formed. The corners of the metal plate 23 can also be R-chamfered or C-chamfered. The size of the metal plate 23 is smaller than the size of the insulating board 21, and the metal plate 23 is formed on the entire surface of the insulating board 21 except for the edge portion. The metal plate 23 is mainly composed of a metal with excellent thermal conductivity. The surface of the metal plate 23 can be subjected to a plating treatment, and the metal of the metal plate 23 is, for example, copper, aluminum, or an alloy including at least one of these metals. At this time, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy. The corrosion resistance of the metal plate 23 after the plating treatment is improved.

[0050] As the insulating circuit board 20 having such a configuration, for example, a DCB (Direct Copper Bonding) board or an AMB (Active Metal Brazed) board can be used. A cooler (not shown) can be mounted on the back surface of the insulating circuit board 20 (semiconductor module 1) via a bonding member. Thereby, the heat dissipation performance of the semiconductor module 1 is improved. The cooler can be constituted of, for example, aluminum, iron, silver, copper, or an alloy containing at least one of these metals and having excellent thermal conductivity. In addition, examples of the cooler include a heat sink and a water-cooling-based cooling device. A plurality of fins can be formed on the heat sink. Examples of the bonding member include solder and a thermal interface material (TIM). Solder has, for example, at least any one of aluminum alloy, titanium alloy, magnesium alloy, zirconium alloy, and silicon alloy as a main component. It can be a thermal interface material. TIM is, for example, a general term for various thermal conductive greases, elastomer sheets, RTV (Room Temperature Vulcanization) rubbers, gels, and phase change materials.

[0051] The semiconductor chips 30a and 30b can be constituted mainly of silicon, for example. The semiconductor chip 30a is a switching element. The switching element is, for example, an IGBT (Integrated Gate Bipolar Transistor) or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). When the semiconductor chip 30a is an IGBT, a collector electrode is provided as a main electrode on the back surface, a gate electrode as a control electrode is provided on the front surface, and an emitter electrode is provided as a main electrode. When the semiconductor chip 30a is a power MOSFET, a drain electrode is provided as a main electrode on the back surface, a gate electrode as a control electrode is provided on the front surface, and a source electrode is provided as a main electrode.

[0052] In addition, the semiconductor chip 30b is a diode element. As the diode element, for example, an SBD (Schottky Barrier Diode) or a PiN (P-intrinsic-N) diode can be used as an FWD (Free Wheeling Diode). Such a semiconductor chip 30b has a cathode electrode as a main electrode on the back surface and an anode electrode as a main electrode on the front surface. The back surface sides of the semiconductor chips 30a and 30b are bonded to a predetermined conductive pattern 22 via a bonding member (not shown).

[0053] Alternatively, a semiconductor chip including an RC (Reverse-Conducting)-IGBT made of silicon may be used instead of the semiconductor chips 30a and 30b. The RC-IGBT combines the functions of an IGBT as a switching element and an FWD as a diode element. A collector electrode is provided as a main electrode on the back surface of such a semiconductor chip, a gate electrode is provided as a control electrode on the front surface of such a semiconductor chip, and an emitter electrode is provided as a main electrode.

[0054] Alternatively, a semiconductor chip including a power MOSFET made of silicon carbide may be used instead of the RC-IGBT. The body diode of the power MOSFET can perform the same function as the FWD of the RC-IGBT. A collector electrode is provided as a main electrode on the back surface of such a semiconductor chip, a gate electrode is provided as a control electrode on the front surface of such a semiconductor chip, and an emitter electrode is provided as a main electrode.

[0055] It should be noted that the bonding components of the semiconductor chips 30a and 30b to the conductive pattern 22 may be, for example, solder or a metal sintered body. Lead-free solder is used. The lead-free solder has, for example, at least one of alloys composed of tin-silver-copper, tin-zinc-bismuth, tin-copper, and tin-silver-indium-bismuth as the main component. In addition, additives may be included in the solder. The additives are, for example, nickel, germanium, cobalt, or silicon. Since the solder contains additives, the wettability, gloss, and bonding strength are improved, thereby enabling an improvement in reliability. The metal sintered body has, for example, silver and silver alloys as the main component.

[0056] It should be noted that in order for the semiconductor module 1 to achieve the desired function, an electronic component 30c may be arranged on the conductive pattern 22. Examples of the electronic component 30c according to this function include a thermistor and a current sensor. The bonding of the electronic component 30c to the conductive pattern 22 may also use the above-mentioned bonding components.

[0057] The external connection terminal 32 is electrically connected to the conductive pattern 22 through the contact member 31. The contact member 31 includes a main body portion having a cylindrical through-hole formed therein and flanges respectively provided at the open end portions of the main body portion. One open end portion of the contact member 31 is bonded to a predetermined position of a plurality of conductive patterns 22 provided on the front surface of the insulating circuit board 20 through a bonding component. The external connection terminal 32 is press-fitted into the other open end portion of the contact member 31. The contact member 31 is made of a metal with excellent conductivity. Such a metal is, for example, copper, aluminum, silver, nickel, or an alloy having at least one of these metals as the main component. In order to improve the corrosion resistance, the surface of the contact member 31 may be subjected to a plating treatment. At this time, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy.

[0058] The external connection terminal 32 is a press fit terminal having a rod-shaped main body portion, tapered front end portions formed at both end portions of the main body portion, and a thick wall portion formed above the main body portion. The front end portion below the external connection terminal 32 is press-fitted into the contact member 31. The front end portion above is then press-fitted into the printed circuit board 40 (see Figure 5 ). The main body portion is, for example, prism-shaped. The external connection terminal 32 is also made of a metal with excellent conductivity. Such a metal is, for example, copper, aluminum, nickel, or an alloy mainly composed of at least one of these metals. In order to improve corrosion resistance, the surface of the external connection terminal 32 can be subjected to a plating treatment. At this time, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy. It should be noted that the external connection terminal 32 is not limited to a press fit terminal, and the main body portion can also be a substantially straight terminal without a thick wall portion.

[0059] In addition, the external connection terminal 32 can be joined to the insulating circuit board 20 without passing through the contact member 31. For example, the external connection terminal 32 can also be directly joined to the conductive pattern 22 of the insulating circuit board 20 by ultrasonic bonding or the like. In addition, the external connection terminal 32 can also be joined to the conductive pattern 22 of the insulating circuit board 20 via solder or brazing, for example.

[0060] In the semiconductor unit 2, between the semiconductor chips 30a and 30b, between the semiconductor chips 30a and 30b and the conductive pattern 22, and between the plurality of conductive patterns 22 are connected by wires 33 to form a power conversion circuit. The wire 33 is mainly composed of, for example, gold, silver, copper, aluminum, or an alloy containing at least one of these.

[0061] The encapsulation member 35 contains a thermosetting resin and a filler contained in the thermosetting resin as a filler. The thermosetting resin is, for example, an epoxy resin, a phenolic resin, or a maleimide resin. The filler is, for example, silica, alumina, boron nitride, or aluminum nitride.

[0062] In the semiconductor module 1, the housing 10 covers the components disposed on the insulating circuit board 20 and is fixed by an adhesive 34 applied along the outer peripheral edge of the insulating circuit board 20 (insulating plate 21). It should be noted that a step 11g is formed along the inside of the lower surface 11f of the outer frame 11 of the housing 10 along the opening 11h. The cross section of the step 11g is L-shaped. The outer peripheral edge of the insulating plate 21 of the insulating circuit board 20 is fitted into the step 11g, and the insulating circuit board 20 covers the opening 11h of the storage area 15 of the housing 10 (outer frame 11).

[0063] The encapsulation member 35 is filled in the accommodation area 15 of the housing 10 to encapsulate the front surface of the insulating circuit board 20. That is, the encapsulation member 35 encapsulates the lower sides of the plurality of conductive patterns 22, semiconductor chips 30a, 30b, contact members 31, external connection terminals 32, and the wire 33. A gap may be provided between the front surface of the encapsulation member 35 and the cover portion 12.

[0064] Next, Figures 5 to 7 A semiconductor module 1 on which a printed circuit board is mounted will be described. Figure 5 FIG. is a first cross-sectional view of a semiconductor module on which a printed circuit board of the first embodiment is mounted, Figure 6 FIG. is a second cross-sectional view of a semiconductor module on which a printed circuit board of the first embodiment is mounted. Figure 7 FIG. is an enlarged cross-sectional view of a semiconductor module on which a printed circuit board of the first embodiment is mounted.

[0065] It should be noted that the semiconductor device 5 is a device in which Figure 1 a printed circuit board 40 is mounted on the semiconductor module 1 shown. Figure 5 And Figure 6 are cross-sectional views of the semiconductor device 5 Figure 1 at the single-dot chain lines Y1 - Y1 and Y2 - Y2 of the semiconductor module 1 shown. Figure 7 FIG. is Figure 6 an enlarged view of the range surrounded by a dashed line in FIG.

[0066] The semiconductor device 5 includes a semiconductor module 1 and a printed circuit board 40. The printed circuit board 40 includes an insulating board (not shown) and a plurality of upper circuit patterns formed on the front surface of the insulating board. In addition, the printed circuit board 40 may include a plurality of lower circuit patterns on the back surface of the insulating board as needed. Further, a plurality of through holes 41 penetrating from the front surface to the back surface of the printed circuit board 40 are formed at positions corresponding to the external connection terminals 32 of the semiconductor module 1. In addition, the printed circuit board 40 is formed with alignment holes 42 at the four corners of the region where the plurality of through holes 41 are formed (see Figure 6 ).

[0067] The insulating board is flat and made of an insulating material. Such a material is a material obtained by impregnating a matrix with a resin. The matrix may be, for example, paper, glass cloth, or glass non-woven fabric. The resin may be, for example, phenolic resin, epoxy resin, or polyimide resin. As a specific example of the insulating board, a paper phenolic substrate, a paper epoxy substrate, a glass epoxy substrate, a glass polyimide substrate, or a glass composite substrate may be used. Such an insulating board is also rectangular in plan view. The corners of the insulating board may be R-chamfered or C-chamfered.

[0068] The upper circuit pattern and the lower circuit pattern are formed in a plurality of pattern shapes so as to constitute a predetermined circuit. The upper circuit pattern and the lower circuit pattern are made of a material with excellent conductivity. As such a material, for example, it is made of silver, copper, nickel, or an alloy containing at least one of these metals. In order to improve corrosion resistance, the surfaces of the upper circuit pattern and the lower circuit pattern may also be subjected to plating treatment. Materials used in this plating treatment include nickel, nickel-phosphorus alloy, nickel-boron alloy, etc. In addition, the through hole 41 is appropriately electrically connected to at least one of the upper circuit pattern and the lower circuit pattern.

[0069] The external connection terminals 32 of the semiconductor module 1 are press-fitted into the through holes 41 of such a printed circuit board 40. In addition, the printed circuit board 40 is fixed to the semiconductor module 1 by self-tapping screws 50 inserted into the alignment holes 42. Thus, the printed circuit board 40 is electrically connected to the semiconductor module 1. It should be noted that when the external connection terminals 32 are not press-fit terminals but are straight, the external connection terminals 32 can be respectively inserted into the through holes 41 and fixed in the through holes 41 using solder.

[0070] If the printed circuit board 40 is press-fitted into the external connection terminals 32, the back surface of the printed circuit board 40 abuts against the upper surface 11e of the housing 10 (outer frame 11). Then, the alignment holes 42 of the printed circuit board 40 are located at the fastening portions 13 of the housing 10 (outer frame 11). The self-tapping screws 50 are inserted through the alignment holes 42 of the printed circuit board 40 and mounted on the housing 10 (outer frame 11).

[0071] As described above, when looking down at the upper surface 11e of the side walls 11b, 11d, the fastening portions 13 are respectively formed on the side walls 11b, 11d closer to the side walls 11a, 11c. The fastening portion 13 includes a boss portion 13a, a fastening hole 13b, a fastening surface 13c, and a fastening bottom surface 13d.

[0072] The boss portion 13a is formed so as to continuously surround the periphery of the fastening hole 13b on the upper surface 11e in a ring shape. The fastening hole 13b is cylindrical. The fastening hole 13b is, for example, cylindrical with a circular shape in plan view. The fastening hole 13b does not reach the lower surface 11f from the upper surface 11e of the outer frame 11, but is formed longer (deeper) than the self-tapping screw 50. The fastening hole 13b is an area surrounded by the fastening surface 13c and the fastening bottom surface 13d. The fastening surface 13c is a curved surface that extends from the upper surface 11e to the lower surface 11f of the outer frame 11. The fastening surface 13c is substantially smooth before the self-tapping screw 50 is screwed in. If the self-tapping screw 50 is screwed in, the fastening surface 13c forms grooves in a spiral manner by the thread teeth of the self-tapping screw 50. The fastening bottom surface 13d is connected to the lowermost end of the fastening surface 13c. Here, the fastening bottom surface 13d is substantially circular in plan view. It should be noted that voids V are included near the inner sides of the lower side (-Z direction) of the fastening surface 13c and the fastening bottom surface 13d respectively. There are hardly any voids V near the inner side in the upper side (+Z direction) of the fastening surface 13c.

[0073] The self-tapping screw 50 includes a head 51 and a threaded portion 52. The head 51 is integrally joined to the other end portion of the threaded portion 52. The other end portion of the threaded portion 52 refers to the end portion opposite to the front end portion of the cylindrical threaded portion 52. The surface of the head 51 joined to the other end portion of the threaded portion 52 may be substantially a smooth main surface. In side view, the head 51 may be rectangular, semi-spherical, or trapezoidal. The diameter of the head 51 is longer than the diameter of the threaded portion 52, for example, more than 2 times and less than 4 times the diameter of the threaded portion 52.

[0074] The threaded portion 52 is cylindrical, and the front end portion ( Figure 7 in the -Z direction side) has a reduced diameter. Thread teeth are spirally formed on the side portion (main body portion) of the threaded portion 52 except for the front end portion. The diameter of the threaded portion 52 corresponds to the diameter of the fastening hole 13b.

[0075] Such a self-tapping screw 50 is made of a material expected to have high strength. The material is, for example, steel, stainless steel, brass, aluminum, magnesium, plastic, or titanium. The self-tapping screw 50 is inserted through the alignment hole 42 of the printed circuit board 40. If it is rotated and enters the fastening hole 13b of the housing 10 (outer frame 11), the thread teeth of the self-tapping screw 50 enter along the -Z direction while forming grooves in the fastening surface 13c. Thus, the self-tapping screw 50 is screwed into the fastening hole 13b.

[0076] In addition, the columnar mark 16 is formed on the side of the fastening hole 13b closer to the accommodation area 15 in a manner parallel to the fastening hole 13b. The columnar mark 16 is a hole extending from the upper surface 11e of the outer frame 11 to the lower surface 11f. The columnar mark 16 is columnar and longer (deeper) than the self-tapping screw 50 screwed into the fastening hole 13b. The columnar mark 16 is, for example, prismatic. The length (depth) of the columnar mark 16 from the upper surface 11e to the lower end portion may be shorter (shallower) than the length (depth) of the fastening hole 13b from the upper surface 11e to the lower end portion. The length (depth) of the columnar mark 16 from the upper surface 11e to the lower end portion may be at least 40% or more and 50% or less relative to the length (depth) of the fastening hole 13b from the upper surface 11e to the lower end portion.

[0077] Next, use Figures 8 to 12 to describe the manufacturing method of the housing 10 included in the manufacturing method of such a semiconductor module 1. Figure 8 is a flowchart showing the manufacturing method of the housing included in the semiconductor module of the first embodiment. Figure 9 is a top view of the molding device of the first embodiment. Figure 10 is a first cross-sectional view of the molding die included in the molding device of the first embodiment, Figure 11 is a second cross-sectional view of the molding die included in the molding device of the first embodiment, Figure 12 is a third cross-sectional view of the molding die included in the molding device of the first embodiment. It should be noted that hereinafter, although the Figure 9 range A will be described, the Figure 9 same applies to the other three corners of the outer frame 11 in this Figure 10 Regarding the range A of the corner of the outer frame 11 surrounded by the Figure 9 dashed line, a cross-sectional view parallel to the X-Y plane is shown. Figure 11 Shows Figure 9 a cross-sectional view taken along the single-dot chain line X-X. Figure 12 Shows Figure 9 a cross-sectional view taken along the single-dot chain line Y-Y.

[0078] First, a preparation process (step S10) for preparing the components required for manufacturing the housing 10 is performed. Examples of the components prepared here include the molding material for the outer frame 11, the metal member that becomes the mounting portion 14, and the molding device described later. In addition to the components listed here, necessary components may also be prepared.

[0079] Next, a molding device placement process (step S11) for placing the molding device is performed. As Figure 9 shown, the placed molding device 3 includes at least a molding die 4, sprue gates 62a, 62b, runners 62c, 62d, and gates 63a to 63d.

[0080] The molding die 4 includes a first die member 60 and a second die member 64. The first die member 60 is box-shaped and has a cavity 61 formed inside. The first die member 60 includes side surfaces 60a to 60d that surround the four sides in a top view in sequence. It should be noted that the side surfaces 60b and 60d correspond to the side walls 11b and 11d of the outer frame 11 formed in the cavity 61. The side surfaces 60a and 60c correspond to the side walls 11a and 11c of the outer frame 11 formed in the cavity 61. In addition, injection ports 60bd, 60bc and injection ports 60db, 60da that communicate with the cavity 61 are respectively formed in the side surfaces 60b and 60d.

[0081] The injection ports 60bd, 60bc and the injection ports 60db, 60da are respectively located inside (±X direction) of the side surfaces 60a and 60c of the side surfaces 60b and 60d at a predetermined distance in a top view. In addition, the injection ports 60bd, 60bc and the injection ports 60db, 60da are located near the bottom surfaces of the side surfaces 60b and 60d in a side view. That is, the injection ports 60bd, 60bc and the injection ports 60db, 60da are provided at positions corresponding to the outermost surfaces 11b1, 11b5 and the outermost surfaces 11d1, 11d5 of the fastening portions of the outer frame 11 and the upper surface 11e connecting the inclined surfaces 11d2, 11d4 and the inclined surfaces 11b2, 11b4 in the side surfaces 60b and 60d in a top view.

[0082] In addition, the cavity 61 of the first die member 60 includes a molding space 61a for forming the outer frame 11. As Figures 10 to 12 shown, the molding space 61a includes: molding inner surfaces 60d2, 60c2 that divide the outer frame 11 and the storage area 15 of the outer frame 11; molding outer surfaces 60d1, 60c1 provided outside the molding inner surfaces 60d2, 60c2 and in contact with the side walls 11d, 11c of the outer frame 11; and molding bottom surfaces 60d3, 60c3 that connect the molding inner surfaces 60d2, 60c2 and the molding outer surfaces 60d1, 60c1 and are in contact with the lower surface 11f of the outer frame 11. It should be noted that the widths of the molding bottom surfaces 60d3, 60c3 correspond to the thicknesses of the side walls 11d, 11c of the outer frame 11. In addition, in the molding outer surface 60d1, the injection port 60da communicating with the molding space 61a is formed to be separated inward (-X direction) from the end portion of the molding outer surface 60d1 in the (+X direction side) in a top view.

[0083] In addition, the first die member 60 includes a die pin portion 62. The die pin portion 62 is rod-shaped and corresponds to the fastening hole 13b included in the outer frame 11. The die pin portion 62 is vertically arranged at a corner of the molding space 61a with respect to the molding bottom surface 60d3 in a top view. It should be noted that the die pin portion 62 can be integrally formed with the first die member 60.

[0084] The second mold component 64 is rod-shaped and corresponds to the columnar mark 16 included in the outer frame 11. Here, as an example, the second mold component 64 is columnar in a rectangular shape when viewed from above. In addition, the second mold component 64 is arranged in the molding space 61a so as to be parallel to the mold pin portion 62 at a position between the mold pin portion 62 and the injection port 60da and closer to the inner molding surface 60d2 than the outer molding surface 60d1 when viewed from above. That is, although the second mold component 64 is arranged so as to block the gap between the inner molding surface 60d2 and the mold pin portion 62 on the injection port 60da side, it does not completely block. The second mold component 64 is preferably separated by 1 mm or more from the mold pin portion 62 toward the injection port 60da (-X direction) side when viewed from above. Since the second mold component 64 corresponds to the columnar mark 16 included in the outer frame 11, it has the same length as the columnar mark 16. That is, the length from the lower end portion of the second mold component 64 in the molding space 61a is at least 40% or more and 50% or less of the length from the lower end portion of the mold pin portion 62 in the molding space 61a. It should be noted that the case where the second mold component 64 and the mold pin portion 62 have the same length is shown here.

[0085] The filled molding material flows into the runners 62c, 62d through the gates 62a, 62b. The runners 62c, 62d cause the molding material flowing in from the gates 62a, 62b to flow into the gates 63a, 63b and the gates 63c, 63d. The gates 63a, 63b and the gates 63c, 63d are respectively connected to the injection ports 60da, 60db and the injection ports 60bc, 60bd. The gates 63a, 63b and the gates 63c, 63d cause the molding material flowing in from the runners 62c, 62d to be filled into the cavity 61 of the first mold component 60 from the injection ports 60da, 60db and the injection ports 60bc, 60bd.

[0086] A metal part serving as the mounting portion 14 is placed at a predetermined position in the cavity 61 of such a molding die 4.

[0087] Next, an injection process (step S12) of injecting a molding material into the cavity 61 of the molding die 4 is performed. While maintaining the molding die 4 at a predetermined temperature, the molten molding material flows in from the gates 62a, 62b of the molding device 3 and is injected into the cavity 61 (molding space 61a) of the molding die 4. The flow of the molding material in the cavity 61 of the molding die 4 at this time will be described later.

[0088] Next, a solidification process (step S13) of solidifying the molding material injected into the cavity 61 of the molding die 4 is performed. The molding die 4 filled with the molding material in the cavity 61 is cooled to a predetermined temperature and maintained at this temperature for a certain period of time for cooling.

[0089] Next, a molded product removal process (step S14) of removing the molded product from the molding die 4 is performed. The molding die 4 is opened, and the molded product in the molding die 4 is removed by protruding with the protruding pins. By separating the molding die 4, the die pin portion 62 of the molded product and the second die member 64 are pulled out, thereby forming the fastening hole 13b and the columnar mark 16.

[0090] Next, a gate removal process (step S15) of removing the portions corresponding to the gates 63a to 63d from the molded product taken out in step S14 is performed. The molded product taken out in step S14 remains in a state where the portions corresponding to the gates 63a to 63d are connected. By removing this portion, the housing 10 can be obtained. The gate marks S on the side walls 11b and 11d of the housing 10 are the portions where the portions corresponding to the gates 63a to 63d are connected. It should be noted that the removal of the portions corresponding to the gates 63a to 63d can be, for example, breaking. Or, when the portions corresponding to the gates 63a to 63d are too thick to break, they can be cut off using a cutter, for example.

[0091] On the other hand, the semiconductor chips 30a and 30b and the contact member 31 are joined to the predetermined conductive pattern 22 of the insulating circuit board 20 using the joining member. Wiring is performed using the wire 33. The external connection terminal 32 is pressed into the contact member 31. The semiconductor unit 2 thus formed is mounted from the opening 11h on the lower surface 11f of the housing 10. At this time, the external connection terminal 32 is inserted through the terminal hole 12a of the lid portion 12 of the housing 10. In addition, at this time, the outer edge of the insulating circuit board 20 is fixed to the step 11g of the housing 10 via the adhesive 34 applied to the outer edge. The encapsulation member 35 is filled in the accommodation area 15 in the housing 10, thereby encapsulating the components on the front surface of the insulating circuit board 20. Thus, the semiconductor module 1 can be obtained.

[0092] Here, a comparative example of the manufacturing method of the housing 10 (outer frame 11) with respect to the first embodiment will be described. In the comparative example, the housing 10 is manufactured without using the second die member 64 as compared with the molding die 4 of the first embodiment. That is, the housing 10 of the comparative example is manufactured using only the first die member 60. The housing 10 of the comparative example is also manufactured according to Figure 8 the flowchart. The flow of the molding material in the case of using only the first die member 60 in the injection process in step S12 is described using Figure 13 ... Figure 13 is a first cross-sectional view showing the injection process included in the manufacturing method of the housing of the comparative example. It should be noted that Figure 13 the solid-line arrows indicate the flow of the molding material. In addition, Figure 13 corresponds to Figure 10 and, from Figure 10Remove the second mold component 64.

[0093] The molding material flowing in from the sprue 62a passes through the runner 62c and the gate 63a, and is injected into the molding space 61a from the injection port 60da on the side surface 60d of the first mold component 60. The molding material injected into the molding space 61a diffuses within the molding space 61a. The molding material flows from the area surrounded by the molding inner surface 60d2, the molding outer surface 60d1, and the molding bottom surface 60d3 into the area surrounded by the molding inner surface 60c2, the molding outer surface 60c1, and the molding bottom surface 60c3. At this time, the molding material flows in the gap B (dashed line area) between the mold pin portion 62 and the molding inner surface 60d2.

[0094] If the molding material flows into the gap B that is narrow enough compared to other parts, the flow rate in the gap B decreases. Therefore, the molding material flows poorly around the mold pin portion 62 and is more likely to stay around it compared to other parts. Therefore, the molding material around the mold pin portion 62 is likely to cause shrinkage.

[0095] In such a state, if the curing of the molding material starts in the curing process of step S13, the molding material in the gap B cures last, and voids are generated and directly included therein. Thereafter, the housing 10 can be obtained through steps S14 and S15.

[0096] Next, use Figure 14 To describe the fastening holes 13b of the housing 10 (outer frame 11) manufactured in this way. Figure 14 It is an enlarged sectional view of the housing of the comparative example. It should be noted that Figure 14 And Figure 7 Corresponds to before installing the self-tapping screw 50.

[0097] In the housing 10 manufactured using the molding die 4 of the comparative example, a large number of voids V are contained in the vicinity of the inner side of the fastening surface 13c of the fastening hole 13b near the storage area 15 side. In this case, a plurality of voids V exist throughout the entire ±Z direction of the fastening surface 13c. Similarly, voids V are also contained near the inner side of the fastening bottom surface 13d of the fastening hole 13b.

[0098] In this way, the self-tapping screw 50 is screwed into the fastening hole 13b where voids V exist inside the fastening surface 13c. If the self-tapping screw 50 is screwed, the fastening surface 13c forms grooves in a spiral manner by the thread teeth of the self-tapping screw 50. However, the strength of the fastening surface 13c containing voids V is weak, and the grooves cannot be properly formed. Therefore, the self-tapping screw 50 cannot be reliably screwed into the fastening hole 13b. The self-tapping screw 50 idles in the fastening hole 13b or falls off from the fastening hole 13b. As a result, the printed circuit board 40 cannot be reliably fixed to the semiconductor module 1.

[0099] On the other hand, the molding die 4 of the first embodiment includes, in addition to the first die member 60, a second die member 64. In the injection step (step S12), the rod-shaped second die member 64 is arranged in the molding space 61a such that, in a plan view, it is parallel to the die pin portion 62 at a position between the die pin portion 62 and the injection port 60da and closer to the molding inner surface 60d2 than the molding outer surface 60d1. That is, the second die member 64 is arranged in parallel with the die pin portion 62 in the gap between the die pin portion 62 and the molding inner surface 60d2 and on the side closer to the injection port 60da. The molding material injected into the molding space 61a is directed toward the gap B between the die pin portion 62 and the molding inner surface 60d2 (refer to Figure 13 ). At this time, the molding material bypasses the second die member 64 in a plan view and flows into the gap B between the die pin portion 62 and the molding inner surface 60d2. That is, due to the second die member 64, the stay of the molding material around the die pin portion 62 is prevented, and the shrinkage of the molding material around the die pin portion 62 is reduced. In such a state, even if the molding material cures in the curing step of step S13, the generation of voids is reduced. In the inner side of the fastening surface 13c of the fastening hole 13b of the outer frame 11 manufactured in this way, almost no void V is included. Therefore, if the self-tapping screw 50 is screwed into the fastening hole 13b, the fastening surface 13c is reliably grooved by the thread teeth of the self-tapping screw 50. The self-tapping screw 50 does not idle relative to the fastening hole 13b and does not fall off, but is reliably fastened. Therefore, in the semiconductor device 5, the printed circuit board 40 can be reliably mounted on the semiconductor module 1.

[0100] For the self-tapping screw 50 to be reliably fastened to the fastening hole 13b, it is sufficient that there is no void V at least above the fastening surface 13c. Specifically, as Figure 7 shown, when the self-tapping screw 50 is screwed into the fastening hole 13b, it is preferable that there is no void V between the upper surface 11e of the fastening surface 13c and about half of the self-tapping screw 50. Therefore, the length (depth) of the columnar mark 16 from the upper surface 11e to the lower end portion is at least 40% or more and 50% or less of the length (depth) of the fastening hole 13b from the upper surface 11e to the lower end portion. That is, the length of the molding space 61a to the lower end portion of the second die member 64 is also at least 40% or more and 50% or less of the length of the molding space 61a to the lower end portion of the die pin portion 62.

[0101] [Second Embodiment] In the second embodiment, a case is where the housing 10 (outer frame 11) including the fastening hole 13b with few voids is manufactured in the molding die 4 of the first embodiment without using the second die member. First, use Figures 15 to 17A semiconductor module and a semiconductor device according to a second embodiment will be described. Figure 15 It is a perspective view of a semiconductor module according to the second embodiment. Figure 16 It is a second cross-sectional view of a semiconductor module with a printed circuit board according to the second embodiment mounted thereon. Figure 17 It is an enlarged cross-sectional view of a semiconductor module with a printed circuit board according to the second embodiment mounted thereon.

[0102] Similar to the first embodiment, the semiconductor module 1a includes a housing 10 and a semiconductor unit 2 housed in the housing 10. A plurality of external connection terminals 32 included in the semiconductor unit 2 extend outward from the front surface of the housing 10. In addition, the inside of the housing 10 is encapsulated with an encapsulating member 35.

[0103] In addition, in the semiconductor device 5a, the printed circuit board 40 is mounted on the semiconductor module 1a using self-tapping screws 50. The self-tapping screws 50 are inserted through through-holes 41 of the printed circuit board 40 and are reliably threadedly engaged with fastening holes 13b of the housing 10.

[0104] However, compared with the case of the first embodiment, the housing 10 does not include the columnar marks 16. In addition, the positions of the gate marks S on the side walls 11b and 11d of the housing 10 are closer to the upper surface 11e side than in the case of the first embodiment.

[0105] The housing 10 of the second embodiment is also manufactured according to the Figure 8 flowchart. Here, the molding device 3 used in the manufacture of the housing 10 of the second embodiment will be described. Figures 18 to 20 It is a plan view of a molding device according to the second embodiment.

[0106] Figure 18 It is a second cross-sectional view of a molding die included in the molding device according to the second embodiment. Figure 19 It is a third cross-sectional view of a molding die included in the molding device according to the second embodiment. It should be noted that hereinafter, although the range A of Figure 20 will be described, the same applies to this range at the other three corners of the outer frame 11 of Figure 18 . Figure 18 It corresponds to Figures 18 to 20 respectively, Figure 9 , Figure 11 and Figure 12 . Figure 19 and Figure 20 are Figure 18 cross-sectional views taken along the single-dot chain lines X-X and Y-Y of

[0107] In the molding device 3 of the second embodiment, as Figure 18 shown, it also includes at least a molding die 4, sprue gates 62a, 62b, runners 62c, 62d, and gates 63a to 63d.

[0108] The molding die 4 of the second embodiment only includes the first die component 60. The first die component 60 has the same configuration as that of the first embodiment. However, the injection port 60da is provided at a position higher in the +Z direction than in the case of the first embodiment. For example, as Figure 19 shown, the injection port 60da is formed on the molding outer surface 60d1 so as to correspond to a position at a height H1 that is 30% or less of the height H0 from the upper surface 11e. The height H0 is the height from the upper surface 11e to the lower surface 11f of the outer frame 11.

[0109] Since the injection port 60da is formed above the molding outer surface 60d1 in the +Z direction, it is possible to suppress a decrease in the flow rate of the molding material above the die pin portion 62 in the +Z direction. Therefore, the residence of the molding material above the die pin portion 62 in the +Z direction is reduced, and the shrinkage of the molding material is reduced. In such a state, even if the molding material is cured in the curing process of step S13, the generation of voids V around the die pin portion 62 in the +Z direction is reduced.

[0110] As described above, in order to reliably fasten the self-tapping screw 50 to the fastening hole 13b, it is sufficient that there is no void V above at least the fastening surface 13c. Therefore, by forming the injection port 60da above the molding outer surface 60d1 in the +Z direction, the generation of voids V around the die pin portion 62 in the +Z direction is reduced. That is, there is almost no void V around the fastening hole 13b of the housing 10 in the +Z direction. Therefore, if the self-tapping screw 50 is screwed into the fastening hole 13b, the fastening surface 13c is reliably formed with grooves by the thread teeth of the self-tapping screw 50. The self-tapping screw 50 does not idle or fall off with respect to the fastening hole 13b, but is reliably fastened. Therefore, in the semiconductor device 5a, the printed circuit board 40 can be reliably mounted on the semiconductor module 1a.

[0111] Only the principles of the present invention are shown above. For those skilled in the art, a large number of further deformations and changes can be made. The present invention is not limited to the exact configurations and application examples shown and described above, and all corresponding deformation examples and equivalents are considered to be within the scope of the present invention based on the appended claims and their equivalents.

Claims

1. A method for manufacturing a semiconductor module, characterized in that: include: a preparation step of preparing a molding die and a molding material, wherein the molding die has a first mold component, the first mold component forms a cavity corresponding to the shape of a shell, the shell has an outer frame that is rectangular in a plan view and surrounds four sides of a storage area provided from a cover portion to a lower surface, a cylindrical fastening portion for screw fastening is formed at a corner of an upper surface of the outer frame, the first mold component is formed with an injection port communicating with the cavity from the outside, and includes a rod-shaped mold pin portion corresponding to the fastening portion; and an injection step of placing the mold pin portion in the mold cavity of the first mold member and injecting the molding material into the mold cavity from the injection port, The mold cavity of the first mold component includes a molding space for molding the outer frame. The molding space is composed of a molding inner surface that divides the outer frame and the storage area, a molding outer surface that is arranged on the outer side of the molding inner surface and is separated from each end toward the inner side when viewed from above and is formed with the injection port that communicates with the molding space, and a molding bottom surface that connects the molding inner surface and the molding outer surface and contacts the lower surface of the outer frame, and the mold pin portion is arranged perpendicularly to the molding bottom surface at a corner of the molding space when viewed from above, The molding mold also includes a rod-shaped second mold component, which is arranged in parallel with the mold pin portion between the mold pin portion and the injection port when viewed from above in the molding space during the injection process and at a position closer to the molding inner surface than the molding outer surface.

2. The method for manufacturing a semiconductor module according to claim 1, wherein: The length of the second mold member in the molding space to the lower end portion is not less than 40% and not more than 50% of the length of the mold pin portion in the molding space to the lower end portion.

3. The method for manufacturing a semiconductor module according to claim 1, wherein: The second mold member is separated from the mold pin portion by 1 mm or more in a plan view.

4. The method for manufacturing a semiconductor module according to claim 1, wherein: The second mold member has a rectangular column shape when viewed from above.

5. The method for manufacturing a semiconductor module according to claim 1, wherein: In the injection process, The molding material injected from the injection port bypasses the second mold member in the molding space and flows between the mold pin portion and the molding inner surface in a plan view.

6. A method for manufacturing a semiconductor module, characterized in that: include: a preparation step of preparing a molding die and a molding material, wherein the molding die has a first mold component, the first mold component forms a cavity corresponding to the shape of a shell, the shell has an outer frame that is rectangular in a plan view and surrounds four sides of a storage area provided from a cover portion to a lower surface, a cylindrical fastening portion for screw fastening is formed at a corner of an upper surface of the outer frame, the first mold component is formed with an injection port communicating with the cavity from the outside, and includes a rod-shaped mold pin portion corresponding to the fastening portion; and an injection step of placing the mold pin portion in the mold cavity of the first mold member and injecting the molding material into the mold cavity from the injection port, The mold cavity of the first mold component includes a molding space for molding the outer frame. The molding space is composed of a molding inner surface that divides the outer frame and the storage area, a molding outer surface that is arranged outside the molding inner surface and is separated from each end toward the inside when viewed from above and is formed with the injection port that communicates with the molding space, and a molding bottom surface that connects the molding inner surface and the molding outer surface and contacts the lower surface of the outer frame. The mold pin portion is disposed perpendicularly to the molding bottom surface at a corner of the molding space when viewed from above. The injection port is formed on the molding outer surface so as to correspond to a position which is 30% or less of the height from the upper surface to the lower surface of the outer frame from the upper surface to the lower surface of the outer frame.

7. The method for manufacturing a semiconductor module according to claim 1 or 6, characterized in that: The outer frame includes a first side wall, a second side wall, a third side wall and a fourth side wall surrounding the storage area, wherein the first side wall and the third side wall are in the long side direction. The injection ports are respectively formed on the molding outer surface corresponding to the first side wall and the third side wall.

8. The method for manufacturing a semiconductor module according to claim 7, characterized in that: In the outer frame, the thickness of the first side wall and the third side wall is greater than the thickness of the second side wall and the third side wall when viewed from above, In addition, the width of a portion of the molding space corresponding to the first side wall and the third side wall is also greater than the width of a portion corresponding to the second side wall and the third side wall in a plan view.

9. The method for manufacturing a semiconductor module according to claim 8, characterized in that: With respect to the first side wall and the third side wall of the outer frame, the fastening portion including the fastening part is configured to be thicker than other portions. The molding outer surface is respectively formed with the injection ports in such a manner as to correspond to the fastening portions of the first side wall and the third side wall, respectively.

10. The method for manufacturing a semiconductor module according to claim 9, characterized in that: The fastening portion includes the upper surface and an inclined surface, the upper surface is formed with the fastening portion, the inclined surface is integrally connected to the upper surface and is inclined toward the lower surface side along the first side wall and the third side wall as it moves away from the fastening portion. The injection ports are respectively formed on the molded outer surfaces so as to correspond to the upper surfaces included in the fastening portions of the first side wall and the third side wall, respectively, in a plan view.

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