Semiconductor module and method for manufacturing semiconductor module

Abstract

The invention relates to a semiconductor module and a manufacturing method of the semiconductor module. The possibility of displacement of a connection terminal in a semiconductor module is reduced. A semiconductor module (100) is provided with: a mounting substrate (30); a semiconductor chip (40) provided on the mounting substrate (30); a cylindrical support conductor (61) provided on the mounting substrate (30); a housing part (20) that houses the mounting substrate (30), the semiconductor chip (40), and the support conductor (61); a connection terminal (62) that is electrically connected to the semiconductor chip (40), and that includes a first end portion that is press-fitted to the support conductor (61) and a second end portion that protrudes from the housing portion (20); and a conductive joining part which is located between the inner wall surface of the support conductor (61) and the outer wall surface of the connection terminal (62) and joins the support conductor (62) and the connection terminal (62).

Description

Technical Field

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

[0002] In the past, there have been proposals for semiconductor modules having a structure in which connection terminals for electrically connecting a semiconductor chip to an external device protrude from an exterior surface. For example, Patent Document 1 discloses a power semiconductor device comprising: a cylindrical electrode fixed to a circuit pattern on which a semiconductor element is mounted; and a connection terminal inserted into the cylindrical electrode.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-165836

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-125803

[0007] Patent Document 3: Japanese Patent Application Publication No. 2010-027813

[0008] Patent Document 4: Japanese Patent Application Publication No. 2010-129670 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] The connection terminal is connected to an external device such as a wiring substrate. Therefore, an external force from the external device acts on the connection terminal, and as a result, there is a possibility that the connection terminal is displaced relative to the cylindrical electrode (and then falls off). Considering the above situation, a technical solution disclosed in the present invention aims to reduce the possibility of displacement of the connection terminal.

[0011] Solutions for solving problems

[0012] In order to solve the above problems, a semiconductor module of a technical solution disclosed in the present invention comprises: a mounting substrate; a semiconductor chip, which is arranged on the mounting substrate; a cylindrical supporting conductor, which is arranged on the mounting substrate; a storage portion, which stores the mounting substrate, the semiconductor chip and the supporting conductor; a connecting terminal, which includes a first end portion pressed into the supporting conductor and a second end portion protruding from the storage portion, and the connecting terminal is electrically connected to the semiconductor chip; and a conductive first joining portion, which is located between the inner wall surface of the supporting conductor and the outer wall surface of the connecting terminal, and joins the supporting conductor to the connecting terminal.

[0013] A method for manufacturing a semiconductor module according to a technical solution of the present invention includes: an installation step, in which a semiconductor chip and a tubular supporting conductor are arranged on a mounting substrate; and a bonding step, in which the supporting conductor is bonded to the connecting terminal using a first bonding portion between an inner wall surface of the supporting conductor and an outer wall surface of the connecting terminal, with the first end portion of the connecting terminal being pressed into the supporting conductor and the second end portion of the connecting terminal protruding from a storage portion that stores the mounting substrate, the semiconductor chip and the supporting conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of the semiconductor module according to the present embodiment.

[0015] Figure 2 This is an exploded perspective view of the external terminals.

[0016] Figure 3 is a cross-sectional view of the external terminal.

[0017] Figure 4 is a cross-sectional view of the external terminal.

[0018] Figure 5 This is a cross-sectional view of a state where a semiconductor module is used.

[0019] Figure 6 This is a flowchart showing the manufacturing process of a semiconductor module.

[0020] Figure 7 This is a diagram for explaining the plating process.

[0021] Figure 8 It is a cross-sectional view of a connection terminal according to a modified example.

[0022] Description of Reference Numerals

[0023] 100, semiconductor module; 200, heat dissipation mechanism; 10, semiconductor unit; 20, storage portion; 21, housing; 22, sealing body; 23, cover; 30, mounting substrate; 31, insulating substrate; 32, metal layer; 33, conductive pattern; 40, semiconductor chip; 41, first electrode; 42, second electrode; 50, lead; 60, external terminal; 61, supporting conductor; 610, cylindrical portion; 611, first flange portion; 612, second flange portion; 614, inner wall surface; 62, connecting terminal; 621, outer wall surface; 63, joint portion; 631, first part; 632, second part. DETAILED DESCRIPTION

[0024] The method for implementing the present disclosure is described with reference to the accompanying drawings. In addition, in each of the drawings, the size and scale of each element may be different from the actual product. In addition, the form described below is an illustrative form envisioned when implementing the present disclosure. Therefore, the scope of the present disclosure is not limited to the form illustrated below.

[0025] A: Structure of the semiconductor module 100

[0026] Figure 1 It is a cross-sectional view of a semiconductor module 100 in one embodiment of the present disclosure. In addition, the Z-axis is assumed in the following description. A direction along the Z-axis is expressed as the Z1 direction, and the direction opposite to the Z1 direction is expressed as the Z2 direction. In addition, in the actual use state, the semiconductor module 100 is set in an arbitrary direction, but in the following description, for convenience, the Z1 direction is assumed to be downward, and the Z2 direction is assumed to be upward. Therefore, sometimes the surface of any element of the semiconductor module 100 facing the Z1 direction is expressed as the "lower surface", and the surface of the element facing the Z2 direction is expressed as the "upper surface". In addition, the situation of observing an object with a line of sight along the Z-axis will be expressed as "looking down" below.

[0027] The semiconductor module 100 of the present embodiment is, for example, a power semiconductor device constituting a power conversion device such as an inverter circuit. Figure 1 As illustrated, the semiconductor module 100 includes a semiconductor unit 10 and a storage portion 20 . The storage portion 20 stores the semiconductor unit 10 .

[0028] The semiconductor unit 10 includes a mounting substrate 30, a semiconductor chip 40, a plurality of leads 50, and a plurality of external terminals 60. Figure 1 Although one semiconductor chip 40 is shown in the figure for convenience, the semiconductor module 100 actually includes a plurality of semiconductor chips 40 .

[0029] The mounting substrate 30 is a wiring substrate on which the semiconductor chip 40 is provided. As the mounting substrate 30, for example, a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Brazing) substrate, or an IMS (Insulated Metal Substrate) substrate is used.

[0030] The mounting substrate 30 is formed by stacking an insulating substrate 31, a metal layer 32, and a plurality of conductive patterns 33. The insulating substrate 31 is a rectangular plate-shaped member formed of an insulating material. The insulating substrate 31 is formed of, for example, a ceramic material such as alumina, aluminum nitride, or silicon nitride, or a resin material such as epoxy resin.

[0031] The metal layer 32 is a thin plate-shaped conductor bonded to the lower surface of the insulating substrate 31. The metal layer 32 is formed of a metal material with high thermal conductivity, such as copper or aluminum, and transfers the heat generated in the semiconductor chip 40 to the heat dissipation mechanism 200. The heat dissipation mechanism 200 is a structure bonded to the metal layer 32, and is formed of a conductive material, such as aluminum or copper.

[0032] Each of the plurality of conductive patterns 33 is a thin plate-shaped conductor provided on the upper surface of the insulating substrate 31. Each conductive pattern 33 is formed of a low-resistance conductive material such as copper or a copper alloy.

[0033] The semiconductor chip 40 is a power semiconductor element provided on the mounting substrate 30, and is used as a switch element for switching the conduction / disconnection of the current. The semiconductor chip 40 of the present embodiment is, for example, an RC-IGBT (Reverse Conducting IGBT: Reverse Conducting Insulated Gate Bipolar Transistor) including an IGBT (Insulated Gate Bipolar Transistor) and a FWD (Free Wheeling Diode: Freewheeling Diode). The semiconductor chip 40 is bonded to the conductive pattern 33 using a bonding portion 34a. The bonding portion 34a is formed of, for example, a conductive bonding material such as solder or a sintered material.

[0034] The semiconductor chip 40 includes a first electrode 41, a second electrode 42, and a control electrode (not shown). The first electrode 41 and the second electrode 42 are electrodes for inputting or outputting a current to be controlled. The first electrode 41 is a collector electrode constituting the lower surface of the semiconductor chip 40, and also functions as a cathode of the FWD. The first electrode 41 of the semiconductor chip 40 is bonded to the conductive pattern 33 using a bonding portion 34a. The second electrode 42 is an emitter electrode constituting the upper surface of the semiconductor chip 40, and also functions as an anode of the FWD. The control electrode is a gate electrode to which a control voltage for controlling the on / off of the semiconductor chip 40 is applied, and the control electrode and the second electrode 42 together constitute the upper surface of the semiconductor chip 40.

[0035] Each of the plurality of leads 50 is a linear conductor that electrically connects a plurality of elements of the semiconductor unit 10. The plurality of leads 50 include leads 50 that connect the conductive patterns 33 to each other and leads 50 that connect the conductive patterns 33 to the semiconductor unit 10.

[0036] Each of the plurality of external terminals 60 is an external terminal 60 for electrically connecting the semiconductor unit 10 to an external device. Each external terminal 60 is bonded to the conductive pattern 33 by a bonding portion 34b. The bonding portion 34b is formed of a conductive bonding material such as solder or a sintered material. The bonding portion 34b is an example of a "second bonding portion".

[0037] Figure 2 It is an exploded perspective view illustrating the structure of the external terminal 60 . Figure 3 is a cross-sectional view of the external terminal 60. Figure 3 , a cross section of the external terminal 60 along the Z axis is shown. Figures 1 to 3 As illustrated, the external terminal 60 includes a supporting conductor 61 , a connecting terminal 62 , and a bonding portion 63 .

[0038] The supporting conductor 61 is a cylindrical conductor provided on the mounting substrate 30. Specifically, Figure 2 and Figure 3 As shown in the example, the supporting conductor 61 is a structure formed integrally of a cylindrical portion 610, a first flange portion 611, and a second flange portion 612. The supporting conductor 61 is formed of a low-resistance conductive material such as copper or a copper alloy. In addition, a plating layer such as tin or nickel may be formed on the supporting conductor 61.

[0039] The cylindrical portion 610 is a cylindrical portion whose central axis is along the Z axis. The inner diameter D of the cylindrical portion 610 is constant throughout the entire range in the axial direction. The cylindrical portion 610 includes a lower end Ea and an upper end Eb located on opposite sides of each other. The lower end Ea is an open end located in the Z1 direction. The upper end Eb is an open end located in the Z2 direction.

[0040] The first flange portion 611 is an annular flange that protrudes radially outward from the lower end portion Ea of the cylindrical portion 610. Figure 3 As shown in the example, the first flange portion 611 supporting the conductor 61 is joined to the conductive pattern 33 by the joint portion 34b. The second flange portion 612 is an annular flange protruding radially outward from the upper end Eb of the cylindrical portion 610. In addition, one or both of the first flange portion 611 and the second flange portion 612 may be omitted.

[0041] The connection terminal 62 is a long strip-shaped conductor. Specifically, the connection terminal 62 is a regular quadrangular prism-shaped structure with a square cross section. The connection terminal 62 is formed of a low-resistance conductive material such as copper or a copper alloy. In addition, a plating layer such as tin or nickel may be formed on the connection terminal 62.

[0042] The connection terminal 62 includes a first end E1 and a second end E2 located on opposite sides of each other in the direction of the Z axis. The first end E1 is an end in the Z1 direction (i.e., a lower end). The first end E1 is inserted into the supporting conductor 61. The second end E2 is an end in the Z2 direction (i.e., an upper end). The total length L of the connection terminal 62 exceeds the total length H of the supporting conductor 61.

[0043] The connection terminal 62 is supported by the supporting conductor 61 by being inserted into the supporting conductor 61. Figure 3As shown in the example, the first end E1 of the connection terminal 62 is not in contact with the conductive pattern 33. That is, when the connection terminal 62 is inserted into the supporting conductor 61, a gap is ensured between the first end E1 and the conductive pattern 33. On the other hand, the second end E2 protrudes from the upper end Eb of the supporting conductor 61 in the Z2 direction.

[0044] Figure 4 is a cross-sectional view of the external terminal 60. Specifically, Figure 4 The middle figure shows a cross section perpendicular to the Z axis passing through the cylindrical portion 610 at the external terminal 60. Figure 4 As shown in the example, the inner diameter D of the cylindrical portion 610 of the support conductor 61 is slightly smaller than the diagonal length G of the connection terminal 62 . Therefore, the portion of the connection terminal 62 located inside the support conductor 61 contacts the inner wall surface 614 of the support conductor 61 .

[0045] That is, the four corners of the cross section of the connection terminal 62 press the inner wall surface 614 of the supporting conductor 61 outward in the radial direction. Figure 4 As illustrated, the portion of the support conductor 61 pressed by the corner of the connection terminal 62 protrudes outward in the radial direction.

[0046] As can be understood from the above description, the first end E1 of the connection terminal 62 is pressed into the support conductor 61. Therefore, the connection terminal 62 is electrically connected to the semiconductor chip 40 via the support conductor 61 and the conductive pattern 33. Figure 4 As illustrated, the region of the outer wall surface 621 of the connection terminal 62 excluding the corner portion faces the inner wall surface 614 of the support conductor 61 with the gap S therebetween.

[0047] The joint 63 is a conductor that joins the supporting conductor 61 and the connecting terminal 62 to each other, and is formed of a conductive joint 63 such as solder or sintered material. The joint 63 is formed of, for example, an alloy material having tin as a main component and containing bismuth, copper, or nickel. The joint 63 is an example of a "first joint".

[0048] like Figure 2 As shown in the example, the joint portion 63 covers a portion of the connection terminal 62 including the first end E1. The remaining portion of the connection terminal 62 including the second end E2 is not formed with the joint portion 63. That is, the remaining portion of the connection terminal 62 including the second end E2 is exposed from the joint portion 63.

[0049] like Figure 3 As shown in the example, the joint portion 63 includes a first portion 631 and a second portion 632. The first portion 631 is a portion located between the inner wall surface 614 of the supporting conductor 61 and the outer wall surface 621 of the connecting terminal 62. Figure 4 As shown in the example, the first portion 631 fills the arc-shaped gap S between the inner wall surface 614 of the supporting conductor 61 and the outer wall surface 621 of the connecting terminal 62. Specifically, the bonding material covering the connecting terminal 62 enters the gap S by melting, and the bonding portion 63 is formed by solidifying the bonding material in the gap S. The first portion 631 also covers the end surface of the first end portion E1.

[0050] On the other hand, the second portion 632 is a portion of the bonding portion 63 located closer to the Z2 direction than the upper end Eb of the supporting conductor 61. That is, the second portion 632 is a portion of the bonding portion 63 exposed from the supporting conductor 61.

[0051] Figure 1 The storage section 20 stores the semiconductor unit 10 described above. Specifically, the storage section 20 stores the mounting substrate 30, the semiconductor chip 40, the plurality of leads 50, and the supporting conductors 61 of the external terminals 60. The storage section 20 of this embodiment includes a housing 21, a sealing body 22, and a cover 23.

[0052] The housing 21 is a rectangular frame-shaped structure surrounding the semiconductor unit 10. The mounting substrate 30 is fixed to the housing 21 by, for example, an adhesive. The housing 21 is formed of various insulating resins such as PPS (polyphenylene sulfide) resin, PBT (polybutylene terephthalate) resin, PBS (polybutylenesuccinate) resin, PA (polyamide) resin, or ABS (acrylonitrile-butadiene-styrene) resin.

[0053] The sealing body 22 is an insulating material filled in the internal space of the case 21 and seals the semiconductor unit 10. That is, the sealing body 22 is filled in the internal space surrounded by the case 21 with the mounting substrate 30 as the bottom surface.

[0054] The sealing body 22 is formed of a resin material softer than the housing 21. For example, the sealing body 22 is formed of silicone. However, the material of the sealing body 22 is not limited to the above examples. For example, the sealing body 22 may be formed of a resin material such as rubber (such as silicone rubber) that is softer than the housing 21. In addition, for example, various fillers such as silicon oxide or aluminum oxide may be contained in the sealing body 22.

[0055] The cover 23 is a flat plate-shaped member that closes the opening of the housing 21. Each connection terminal 62 passes through a through hole formed in the cover 23. Figure 1As shown in the example, the second end E2 of each connection terminal 62 protrudes from the storage portion 20. Specifically, the second end E2 protrudes in the Z2 direction from the outer surface F of the storage portion 20 facing the Z2 direction. The outer surface F is a surface of the storage portion 20 including the top surface of the housing 21 and the upper surface of the cover 23. In addition, the cover 23 may also be formed integrally with the housing 21.

[0056] Figure 5 2 is a cross-sectional view showing a semiconductor module 100 in use. Figure 5 As illustrated, in the use state, the wiring substrate 70 is fixed to the semiconductor module 100. The wiring substrate 70 is, for example, a hard circuit substrate on which a drive circuit and a power supply circuit used for driving the semiconductor module 100 are mounted.

[0057] Specifically, the wiring substrate 70 is fixed to the semiconductor module 100 in a state facing the outer surface F of the storage portion 20. The wiring substrate 70 is fixed to the housing 21 by fasteners (not shown) such as screws or bolts. Each connection terminal 62 is inserted into a through hole 71 formed in the wiring substrate 70. The second end E2 is bonded to the wiring substrate 70 by a conductive bonding material such as solder or a sintered material.

[0058] As described above, each connection terminal 62 is joined to the wiring substrate 70. Therefore, an external force in the Z2 direction is sometimes applied to each connection terminal 62 from the wiring substrate 70. For example, in the process of replacing the wiring substrate 70, when the installed wiring substrate 70 is moved in the Z2 direction to be removed, an external force in the Z2 direction also acts on the connection terminal 62. In the present embodiment, the supporting conductor 61 and the connection terminal 62 are joined by the joint portion 63, so that the displacement (and thus falling off) of the connection terminal 62 caused by the external force from the wiring substrate 70 can be suppressed compared to a structure in which the connection terminal 62 is simply inserted into the supporting conductor 61.

[0059] Next, the melting point (solid phase temperature Ts, liquid phase temperature Tl) of the bonding material used for forming the bonding portion 63 is described. The solid phase temperature Ts of the bonding portion 63 is the temperature at which the solid phase bonding material begins to melt during the temperature rise process. The liquid phase temperature Tl of the bonding portion 63 is the temperature at which the bonding material completely melts during the temperature rise process. That is, the liquid phase temperature Tl is the temperature at which the liquid phase bonding material begins to solidify during the temperature drop process, and the solid phase temperature Ts is the temperature at which the bonding material completely solidifies during the temperature drop process. The liquid phase temperature Tl exceeds the solid phase temperature Ts (Tl>Ts).

[0060] First, the solid phase temperature Ts of the joint 63 exceeds the maximum ambient temperature Tc of the semiconductor module 100 (Ts>Tc). The maximum ambient temperature Tc is the highest temperature of the environment in which the semiconductor module 100 is used. For example, the maximum value of the operating temperature in the specifications of the semiconductor module 100 is the maximum ambient temperature Tc. In addition, for example, the maximum shell temperature in the specifications of the semiconductor module 100 may be set to the maximum ambient temperature Tc. The maximum shell temperature is the maximum temperature of the shell 21 assumed under normal use. As described above, according to the structure of the present embodiment, since the solid phase temperature Ts of the joint 63 exceeds the maximum ambient temperature Tc of the semiconductor module 100, the possibility of the joint 63 melting in the actual use environment of the semiconductor module 100 can be reduced.

[0061] In addition, the liquid phase temperature Tl of the bonding portion 63 is lower than the maximum junction temperature Tjmax of the semiconductor chip 40 (Tl<Tjmax). The maximum junction temperature Tjmax is the maximum value of the temperature at which the semiconductor chip 40 operates appropriately.

[0062] In addition, the liquid phase temperature T1 of the joint portion 63 is lower than the solid phase temperature Tref of the joint portion 34a and the joint portion 34b (T1<Tref). According to the above form, the liquid phase temperature T1 of the joint portion 63 for joining the connection terminal 62 and the support conductor 61 is lower than the solid phase temperature Tref of the joint portion 34a and the joint portion 34b. Therefore, the connection terminal 62 and the support conductor 61 can be joined by melting and solidifying the joint portion 63 while maintaining the joining between the semiconductor chip 40 and the mounting substrate 30 by the joint portion 34a and the joining between the mounting substrate 30 and the support conductor 61 by the joint portion 34b.

[0063] In addition, during the process of melting the bonding material used to bond each connection terminal 62 to the wiring substrate 70, the temperature of the bonding portion 63 of the external terminal 60 may rise. However, at the stage of setting the wiring substrate 70, since the heat dissipation mechanism 200 is bonded to the metal layer 32 of the mounting substrate 30, the excessive rise in the temperature of the bonding portion 63 is suppressed by the heat dissipation from the heat dissipation mechanism 200. Therefore, when the wiring substrate 70 is set, the possibility of the bonding portion 63 melting is low. In addition, even if the bonding portion 63 temporarily melts when the wiring substrate 70 is set, the bonding portion 63 will re-solidify by cooling after the wiring substrate 70 is set. Therefore, the bonding between the supporting conductor 61 and the connection terminal 62 can be maintained, and the melting of the bonding portion 63 will not become a particular problem.

[0064] B: Method for manufacturing semiconductor module 100

[0065] A method for manufacturing the semiconductor module 100 exemplified above will be described. Figure 6The diagram is an explanatory diagram of the process of manufacturing the semiconductor module 100 .

[0066] In the mounting step P1, the semiconductor chip 40 and the supporting conductor 61 are placed on the mounting substrate 30. Specifically, first, in step P11, a paste-like bonding material is applied to the surface of the mounting substrate 30, and the semiconductor chip 40 and the supporting conductor 61 are arranged on the bonding material. In step P12 after the step P11, the bonding material is melted and solidified to form the bonding portion 34a and the bonding portion 34b. That is, the semiconductor chip 40 is bonded to the mounting substrate 30 using the bonding portion 34a, and the supporting conductor 61 is bonded to the mounting substrate 30 using the bonding portion 34b. In the wiring step P2 after the mounting step P1, a plurality of leads 50 are formed.

[0067] On the other hand, in the plating step P3, the bonding material C is provided on the connection terminal 62. For example, Figure 7 As illustrated, the connection terminal 62 is immersed in a plating bath of the bonding material C stored in the storage container 80 , and the bonding material C is provided on a portion of the connection terminal 62 including the first end portion E1 .

[0068] The time relationship between the mounting step P1 and the wiring step P2 and the plating step P3 is arbitrary. For example, the plating step P3 may be performed before or after the mounting step P1 and the wiring step P2, or may be performed in parallel with the mounting step P1 or the wiring step P2.

[0069] In the pressing step P4 after the wiring step P2 and the plating step P3 are performed, the connection terminal 62 is pressed into each supporting conductor 61. Specifically, the portion of the connection terminal 62 provided with the bonding material C (a portion including the first end E1) is pressed into the supporting conductor 61. In the stage immediately after the pressing step P4, the bonding material C that becomes the bonding portion 63 is not melted. That is, the bonding portion 63 that bonds the supporting conductor 61 and the connection terminal 62 is in a state of not being formed.

[0070] In the storage step P5 after the press-in step P4, the semiconductor unit 10 is stored in the storage portion 20. First, in the step P51 in the storage step P5, the mounting substrate 30 is fixed to the housing 21. The mounting substrate 30 is fixed, for example, by various adhesives. In the step P52 after the step P51, a resin material is formed in the space surrounded by the housing 21 with the mounting substrate 30 as the bottom surface. Specifically, a liquid resin material such as silicone is filled into the internal space of the housing 21, and the resin material is cured by heating to form the sealing body 22.

[0071] In step P53 after step P52 is performed, the opening of the housing 21 is closed by the cover 23. Each connection terminal 62 is inserted into the through hole of the cover 23. In the stage immediately after the storage step P5 described above, the bonding material C is provided on the portion of the connection terminal 62 located inside the storage portion 20, and the portion of the connection terminal 62 located outside the storage portion 20 is exposed from the bonding material C.

[0072] The steps (P1 to P5) illustrated above are assembly steps of the semiconductor module 100. Immediately after the assembly step, the first end E1 of the connection terminal 62 is pressed into the supporting conductor 61 and the second end E2 of the connection terminal 62 is protruding from the storage portion 20 that stores the semiconductor unit 10. When the assembly of the semiconductor module 100 described above is performed, the inspection step P6 of the semiconductor module 100 is performed before the product is shipped. The inspection step P6 is a step for evaluating the characteristics of the semiconductor chip 40 (pre-shipment inspection).

[0073] The inspection process P6 of this embodiment includes a dynamic characteristic test P61 and a static characteristic test P62. The dynamic characteristic test P61 is a test for evaluating the characteristics of the semiconductor chip 40 while dynamically changing the current supplied to each semiconductor chip 40. The static characteristic test P62 is a test for evaluating the characteristics of the semiconductor chip 40 when a predetermined direct current is supplied. In the dynamic characteristic test P61 and the static characteristic test P62, for example, the electrical characteristics, temperature characteristics, and insulation characteristics of the semiconductor chip 40 are tested.

[0074] In the inspection step P6, the semiconductor chip 40 is driven while the semiconductor module 100 is heated. Specifically, in the inspection step P6, each semiconductor chip 40 is driven while the semiconductor module 100 is heated to a temperature near the maximum junction temperature Tjmax, and whether each semiconductor chip 40 operates properly is evaluated.

[0075] As described above, the liquid phase temperature T1 of the bonding material C used to form the bonding portion 63 is lower than the maximum junction temperature Tjmax of the semiconductor chip 40. Therefore, in the inspection step P6, the semiconductor module 100 is heated to a temperature near the maximum junction temperature Tjmax, so that the bonding material C is melted, and the semiconductor module 100 is cooled during the inspection step P6, so that the bonding material C is solidified. The bonding portion 63 is formed by the melting and solidification of the bonding material C. In addition, as described above with reference to Figure 4 As described above, since the connection terminal 62 is in contact with the inner wall surface 614 of the support conductor 61 , even when the bonding material C is melted in the inspection step P6 , electrical conduction between the support conductor 61 and the connection terminal 62 can be maintained.

[0076] That is, the inspection process P6 of the present embodiment includes a bonding process Q of forming a bonding portion 63 by melting and solidifying the bonding material C. The bonding process Q is a process of bonding the support conductor 61 and the connection terminal 62 using the bonding portion 63 between the inner wall surface 614 of the support conductor 61 and the outer wall surface 621 of the connection terminal 62. The bonding process Q of the present embodiment is a process of melting and solidifying the bonding material C by heating the semiconductor module 100 in the inspection process P6. That is, the bonding process Q is realized by heating the semiconductor module 100 in the inspection process P6. The manufacturing process of the semiconductor module 100 is as described above.

[0077] As described above, in the present embodiment, the first end portion E1 formed with the bonding material C serving as the bonding portion 63 is pressed into the supporting conductor 61. Therefore, compared with, for example, a method of providing the bonding material C after the first end portion E1 is pressed into the supporting conductor 61, it is possible to easily provide the bonding portion 63 between the inner wall surface 614 of the supporting conductor 61 and the outer wall surface 621 of the connecting terminal 62. However, the bonding material C may be injected between the supporting conductor 61 and the connecting terminal 62 after the first end portion E1 is pressed into the supporting conductor 61.

[0078] In addition, in a method (hereinafter referred to as a "comparative example") in which the bonding material C is provided over the entirety of the connection terminal 62 including the first end E1 and the second end E2, there is a possibility that the bonding material C located near the second end E2 solidifies after melting to form a local protrusion (lump). When a protrusion is formed near the second end E2, for example, there is a possibility that the insertion of the second end E2 into the through hole 71 of the wiring substrate 70 is hindered.

[0079] In contrast to the comparative example, in the present embodiment, the bonding material C is provided at the portion of the connection terminal 62 located inside the storage portion 20, and the portion of the connection terminal 62 located outside the storage portion 20 is exposed from the bonding material C. That is, the bonding portion 63 is formed at a portion of the connection terminal 62 including the first end E1, and the second end E2 is exposed from the bonding portion 63. According to the above method, the formation of a protrusion caused by the melting of the bonding material C near the second end E2 is suppressed. Therefore, for example, the bonding of the second end E2 to the wiring substrate 70 or the like can be easily implemented. In addition, in a method in which a local protrusion does not become a particular problem, the bonding material C can also be formed over the entirety of the connection terminal 62 as in the comparative example described above.

[0080] In addition, in the present embodiment, the bonding material C for bonding the supporting conductor 61 and the connecting terminal 62 is melted by heating the semiconductor module 100 in the inspection step P6. That is, the bonding step Q is realized by a part of the inspection step P6. Therefore, compared with a method in which the step of melting the bonding material C is performed independently of the inspection step, the manufacturing process of the semiconductor module 100 is simplified. In the present embodiment, in particular, the liquid phase temperature Tl of the bonding material C is lower than the maximum junction temperature Tjmax of the semiconductor chip 40, so by heating the semiconductor module 100 to the maximum junction temperature Tjmax, the bonding material C can be melted and the supporting conductor 61 and the connecting terminal 62 can be bonded.

[0081] C: Deformation

[0082] Specific modified forms added to the above-exemplified embodiments are exemplified below. Two or more forms arbitrarily selected from the following examples may be appropriately combined within a range that does not conflict.

[0083] (1) In the above embodiment, the cross-section of the connection terminal 62 is exemplified as a square shape, but the shape of the connection terminal 62 is not limited to the above embodiment. Figure 8 As shown in Examples 1 to 3, a strip-shaped member having a polygonal cross section may be used as the connection terminal 62. Alternatively, a strip-shaped member having a circular cross section may be used as the connection terminal 62.

[0084] (2) In the above embodiment, the cylindrical portion 610 of the supporting conductor 61 is exemplified as being cylindrical, but the shape of the supporting conductor 61 is not limited to the above embodiment. For example, a supporting conductor 61 having a square cylindrical shape with a polygonal cross section may be used. That is, the supporting conductor 61 is generally represented as a conductive structure formed in a cylindrical shape into which the connecting terminal 62 can be inserted.

[0085] (3) In the above embodiment, the housing portion 20 is constituted by the case 21 , the sealing body 22 , and the lid 23 , but the present disclosure is also applicable to an embodiment in which the housing portion 20 is formed of a single resin material (full mold).

[0086] In addition, in the above-mentioned embodiment, in the method in which the semiconductor unit 10 is sealed by the soft sealing body 22, since the storage part 20 has a weak holding force on the connection terminal 62, the connection terminal 62 is easily displaced by the action of an external force. Therefore, in the above-mentioned embodiment in which the storage part 20 includes the housing 21 and the soft sealing body 22, a structure that can suppress the displacement of the connection terminal 62 by joining the supporting conductor 61 and the connection terminal 62 using the joining part 63 is particularly effective.

[0087] (4) In the plating step P3 of the above embodiment, a method of immersing the connection terminal 62 in a plating bath of the bonding material C stored in the storage container 80 is exemplified, but the method of providing the bonding material C on the connection terminal 62 is not limited to the above example. For example, the connection terminal 62 may be immersed in a bath in which the bonding material C is melted.

[0088] (5) In the above-mentioned method, the inspection step P6 includes the bonding step Q, but the bonding step Q of bonding the supporting conductor 61 and the connecting terminal 62 by the bonding portion 63 may be performed separately from the inspection step P6. For example, the bonding material C may be melted and solidified between the pressing step P4 and the storage step P5 to form the bonding portion 63. In addition, for example, in the step P52 of forming the sealing body 22 in the storage step P5, the sealing body 22 is solidified by heating the semiconductor module 100. The bonding portion 63 may be formed by melting the bonding material C by heating in the step P52 and solidifying the bonding material C by cooling after melting.

[0089] (6) In the above-mentioned embodiment, the embodiment in which the housing step P5 is performed after the press-in step P4 is performed is exemplified, but the press-in step P4 may be performed after the housing step P5 is performed. For example, in the embodiment in which the upper end Eb of the supporting conductor 61 is opened at the outer surface F of the housing portion 20, the connection terminal 62 may be inserted into the supporting conductor 61 after the housing portion 20 is formed.

[0090] (7) In the above embodiment, the semiconductor chip 40 is exemplified as an RC-IGBT, but the form of the semiconductor chip 40 is not limited to the above embodiment. For example, various electronic components such as IGBT (Insulated Gate Bipolar Transistor) or SBD (Schottky Barrier Diode) can also be used as the semiconductor chip 40. In addition, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) whose semiconductor layer is formed of silicon (Si) or silicon carbide (SiC) can also be used as the semiconductor chip 40. In the embodiment in which the semiconductor chip 40 is composed of MOSFET, the first electrode 41 is a drain electrode, and the second electrode 42 is a source electrode.

[0091] (8) The term “nth” (n is a natural number) in this application is used only as a formal and convenient identifier (label) to distinguish the various elements in the description and does not have any substantial meaning. Therefore, there is no room for restrictive interpretation of the position of the various elements or the order of manufacture based on the term “nth”.

[0092] D: Notes

[0093] According to the above-exemplified embodiment, for example, the following configuration can be understood.

[0094] A semiconductor module of one form (form 1) of the present disclosure comprises: a mounting substrate; a semiconductor chip, which is arranged on the mounting substrate; a cylindrical supporting conductor, which is arranged on the mounting substrate; a storage portion, which stores the mounting substrate, the semiconductor chip and the supporting conductor; a connecting terminal, which includes a first end portion pressed into the supporting conductor and a second end portion protruding from the storage portion, and the connecting terminal is electrically connected to the semiconductor chip; and a conductive first bonding portion, which is located between the inner wall surface of the supporting conductor and the outer wall surface of the connecting terminal, and bonds the supporting conductor to the connecting terminal. In the above manner, the supporting conductor and the connecting terminal are bonded by the first bonding portion, so that the displacement (and thus falling off) of the connecting terminal can be suppressed compared to a structure in which the connecting terminal is simply pressed into the supporting conductor.

[0095] In the specific example of form 1 (form 2), the solid phase temperature of the first joint portion exceeds the maximum ambient temperature of the semiconductor module. In the above manner, since the solid phase temperature of the first joint portion exceeds the maximum ambient temperature of the semiconductor module, the possibility of melting of the first joint portion in the actual use environment of the semiconductor module can be reduced.

[0096] In the specific example of form 1 or form 2 (form 3), the liquid phase temperature of the first bonding portion is lower than the maximum junction temperature of the semiconductor chip. In the above manner, since the liquid phase temperature of the first bonding portion is lower than the maximum junction temperature (bonding portion temperature) of the semiconductor chip, in the process of heating the semiconductor module to the maximum junction temperature, the bonding material can be melted to form the first bonding portion (i.e., the supporting conductor is bonded to the above-mentioned connection terminal).

[0097] In a specific example (Form 4) of any one of Forms 1 to 3, the supporting conductor is bonded to the mounting substrate by a second bonding portion, and the liquidus temperature of the first bonding portion is lower than the solidus temperature of the second bonding portion. According to the above method, the liquidus temperature of the first bonding portion for bonding the connecting terminal to the supporting conductor is lower than the solidus temperature of the second bonding portion for bonding the supporting conductor to the mounting substrate. Therefore, the connecting terminal can be bonded to the supporting conductor by the first bonding portion by melting and solidifying the bonding material while maintaining the bonding between the mounting substrate and the supporting conductor by the second bonding portion.

[0098] In a specific example (form 5) of any one of forms 1 to 4, the storage portion includes: a shell that surrounds the mounting substrate, the semiconductor chip, and the supporting conductor; and a sealing body that fills the internal space of the shell, and the sealing body is softer than the shell. In a manner in which the mounting substrate, the semiconductor chip, and the supporting conductor are sealed by a soft sealing body, since the storage portion weakly holds the connecting terminal, the connecting terminal is easily displaced under the action of, for example, an external force. Therefore, in a structure in which the storage portion includes a shell and a soft sealing body, the structure of the present disclosure that can suppress the displacement of the connecting terminal by utilizing the connection between the supporting conductor and the connecting terminal of the first joint portion is particularly effective.

[0099] In a specific example (form 6) of any one of forms 1 to 5, the first joining portion is formed in a portion of the connecting terminal including the first end, and the second end is exposed from the first joining portion. In a method in which a joining material for forming the first joining portion is arranged throughout the entire connecting terminal including the first end and the second end, there is a possibility that the joining material located near the second end solidifies after melting to form a local protrusion (lump). In the case where a protrusion is formed near the second end, for example, it is possible to hinder the setting of the second end relative to a wiring substrate, etc. (for example, insertion into a mounting hole of a wiring substrate). According to a method in which the first joining portion is formed only in a portion of the connecting terminal including the first end and the second end is exposed from the first joining portion, it is possible to suppress the formation of a local protrusion near the second end caused by the melting of the joining material that becomes the first joining portion. Therefore, it is possible to easily implement, for example, the setting of the second end relative to a wiring substrate, etc.

[0100] A method for manufacturing a semiconductor module according to one form (form 7) of the present disclosure includes: a mounting step in which a semiconductor chip and a tubular supporting conductor are arranged on a mounting substrate; and a bonding step in which the supporting conductor is bonded to the connecting terminal using a first bonding portion between an inner wall surface of the supporting conductor and an outer wall surface of the connecting terminal, while the first end of the connecting terminal is pressed into the supporting conductor and the second end of the connecting terminal protrudes from a storage portion that stores the mounting substrate, the semiconductor chip, and the supporting conductor. In the above manner, the supporting conductor and the connecting terminal are bonded using the first bonding portion, so that the displacement (and thus falling off) of the connecting terminal can be suppressed compared to a structure in which the connecting terminal is simply pressed into the supporting conductor.

[0101] In a specific example of form 7 (form 8), the manufacturing method of the semiconductor module further includes a pressing step before implementing the bonding step, in which the first end is pressed into the supporting conductor, a bonding material to become the first bonding portion is formed at the first end, and in the bonding step, the first bonding portion is formed by melting and solidifying the bonding material. In the above method, the first end formed with the bonding material to become the first bonding portion is pressed into the supporting conductor. Therefore, for example, compared with a method in which the bonding material is provided after the first end is pressed into the supporting conductor, the first bonding portion can be easily provided between the inner wall surface of the supporting conductor and the outer wall surface of the connecting terminal.

[0102] In a specific example of form 7 or form 8 (form 9), the bonding material is provided at the portion of the connection terminal located inside the housing portion, and the portion of the connection terminal located outside the housing portion is exposed from the bonding material. In the above manner, the bonding material is provided at the portion of the connection terminal located inside the housing portion, and the portion of the connection terminal located outside the housing portion is exposed from the bonding material, so that it is possible to suppress the formation of a local protrusion caused by the melting of the bonding material near the second end. Therefore, it is possible to easily implement, for example, the setting of the second end relative to a wiring substrate or the like.

[0103] In a specific example (form 10) of any one of forms 7 to 9, the method for manufacturing the semiconductor module includes an inspection process, in which the inspection is performed while the semiconductor module is heated, and the bonding process is a process of melting and solidifying the bonding material by heating the semiconductor module in the inspection process. According to the above method, the bonding material used to bond the supporting conductor to the connecting terminal is melted by heating the semiconductor module in the inspection process. That is, the bonding process is implemented by a part of the inspection process. Therefore, compared with a method in which the process of melting the bonding material is implemented independently of the inspection process, the manufacturing process of the semiconductor module is simplified.

Claims

1. A semiconductor module, wherein: The semiconductor module has: Install the base plate; A semiconductor chip disposed on the mounting substrate; a cylindrical supporting conductor disposed on the mounting substrate, a housing portion for housing the mounting substrate, the semiconductor chip, and the supporting conductor; a connection terminal including a first end portion pressed into the supporting conductor and a second end portion protruding from the receiving portion, the connection terminal being electrically connected to the semiconductor chip; as well as The conductive first joining portion is located between the inner wall surface of the supporting conductor and the outer wall surface of the connecting terminal, and joins the supporting conductor and the connecting terminal.

2. The semiconductor module according to claim 1, wherein: The solid phase temperature of the first joint portion exceeds the maximum ambient temperature in which the semiconductor module is used.

3. The semiconductor module according to claim 1 or 2, wherein: The liquid phase temperature of the first bonding portion is lower than the maximum junction temperature of the semiconductor chip.

4. The semiconductor module according to claim 1, wherein: The supporting conductor is bonded to the mounting substrate by a second bonding portion. The liquid phase temperature of the first joining portion is lower than the solid phase temperature of the second joining portion.

5. The semiconductor module according to claim 1, wherein: The storage portion comprises: a housing that surrounds the mounting substrate, the semiconductor chip, and the supporting conductor; and a sealing body, which fills the inner space of the housing, The sealing body is softer than the housing.

6. The semiconductor module according to claim 1, wherein: The first bonding portion is formed in a portion of the connection terminal including the first end portion. The second end portion is exposed from the first joining portion.

7. A method for manufacturing a semiconductor module, wherein: The method for manufacturing the semiconductor module comprises: A mounting step of placing the semiconductor chip and the cylindrical supporting conductor on a mounting substrate; and A joining process, in which the supporting conductor is joined to the connecting terminal by utilizing a first joining portion between an inner wall surface of the supporting conductor and an outer wall surface of the connecting terminal, while the first end portion of the connecting terminal is pressed into the supporting conductor and the second end portion of the connecting terminal protrudes from a housing portion that houses the mounting substrate, the semiconductor chip and the supporting conductor.

8. The method for manufacturing a semiconductor module according to claim 7, wherein: The method for manufacturing a semiconductor module further includes a press-fitting step before performing the bonding step, in which the first end portion is press-fitted into the supporting conductor. A bonding material serving as the first bonding portion is formed at the first end portion, In the joining step, the first joining portion is formed by melting and solidifying the joining material.

9. The method for manufacturing a semiconductor module according to claim 8, wherein: The connecting terminal includes a portion inside the receiving portion and a portion outside the receiving portion, The bonding material is disposed on the inner side of the storage portion. A portion of the outer side of the receiving portion is exposed from the bonding material.

10. The method for manufacturing a semiconductor module according to claim 8 or 9, wherein: The manufacturing method of the semiconductor module includes an inspection step in which the semiconductor module is inspected while being heated. The bonding step is a step of melting and solidifying the bonding material by heating the semiconductor module in the inspection step.

Images