Semiconductor module, semiconductor device, and method of manufacturing the semiconductor device

Abstract

To make it difficult for the heat of a molten portion to be transferred to an insulating layer when a terminal of a capacitor is laser-welded to a terminal portion having a laminated structure.SOLUTION: In a terminal portion 14 formed by laminating a second external connection terminal 16, an insulating layer 18, and a first external connection terminal 20, a first external connection terminal 20 to be joined to a positive electrode terminal 38 of a capacitor 30 via a connecting member 40 by laser welding includes a groove portion 26 directly under a weld portion 24 and not in contact with the insulating layer 18 on the side facing the insulating layer 18. The groove portion 26 cuts off heat transfer when the welding heat at the weld portion 24 is transferred to the side of the insulating layer 18. As a result, it is possible to prevent the insulating layer 18 from being altered by the heat of the molten portion and the withstand voltage of the terminal portion 14 being lowered.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor module, a semiconductor device, and a method for manufacturing a semiconductor device. [Background technology]

[0002] A semiconductor module incorporates a power device and has, for example, a power conversion function. Examples of power devices include an insulated gate bipolar transistor (IGBT), a free wheeling diode (FWD), and a metal oxide semiconductor field effect transistor (MOSFET). Such a semiconductor module may have a large-capacity capacitor connected nearby to stabilize the applied DC power supply voltage.

[0003] The semiconductor module and the capacitor are connected to their respective positive and negative power terminals by a connecting member. This connection has traditionally been performed by screw fastening to facilitate the connection process. However, with a screw fastening method, the electrical connection between the connecting member and the terminals tends to have high contact resistance at the joint and to deteriorate significantly over time. Therefore, a method of connecting the connecting member and the terminals by ultrasonic bonding has been proposed (see, for example, Patent Document 1).

[0004] In ultrasonic bonding, a horn is pressed against the joint where the connecting member is to be joined, generating ultrasonic vibrations. This vibration creates a metallurgical bond at the joint interface, electrically and mechanically connecting the connecting member and the terminal.

[0005] Since ultrasonic bonding is a method of applying ultrasonic vibrations to the connecting member and the terminals, the case that supports the terminals must have enough strength to prevent deformation due to the ultrasonic vibrations.

[0006] In response to this, laser welding is known, which can join a connecting member and a terminal together without applying physical stress to the connecting member and the terminal (see, for example, Patent Document 2). In laser welding, overlapping metals are irradiated with a focused laser beam, causing the overlapping metals to melt locally together. The molten portions then solidify, joining the overlapping metals. Because laser welding melts the base material in the direction of the laser beam by locally concentrating laser energy, strict control of the heat input to the base material is required. Even so, in some cases, the molten portion may penetrate the overlapping metals. Therefore, the invention of Patent Document 2 places a protective member with a higher melting point than the metals to be laser-welded on the side of the overlapping metals opposite the laser beam incident side. This prevents penetration by the welding, thereby preventing damage to the surrounding area due to the molten portion.

[0007] Regarding a semiconductor module connected to a capacitor, a technology for providing a terminal portion as follows is also known. That is, a technology for providing a terminal stack portion as the terminal portion of a semiconductor module is known, in which a first power terminal, an insulating sheet, and a second power terminal are stacked in this order, with a portion of the first power terminal exposed from the insulating sheet and the second power terminal positioned on the insulating sheet with a terrace portion of the insulating sheet sandwiched between the portion and the exposed portion (see, for example, Patent Document 3). A first connecting terminal and a second connecting terminal of the capacitor are laser-welded to the first power terminal exposed from the insulating sheet and the second power terminal on the insulating sheet, respectively, of such a terminal stack portion.

[0008] Regarding laser welding, there is known a technique for providing a gap between an upper terminal and a lower terminal, which are internal wiring members of a semiconductor device, when the upper terminal and the lower terminal are laser-welded together (see, for example, Patent Document 4).

[0009] In addition, with regard to laser welding, a technology is known in which a spacer with an air gap hole is inserted between a lead frame, which is a lead material for internal wiring of a semiconductor device, and a heat spreader, which is its joining member, and laser light is irradiated at a position corresponding to the air gap hole to weld the lead frame and the heat spreader (see, for example, Patent Document 5).

[0010] Also, a technique is known in which an electric wiring board including a DC positive wiring board and a DC negative wiring board of a power module used in an inverter device of a power conversion device is fixed to a positive conductor plate and a negative conductor plate of a capacitor module of the power conversion device by laser welding or the like (see, for example, Patent Document 6).

[0011] Also, a technique is known in which a metal plate (electrode member) arranged on the main surface of a semiconductor element bonded to one conductive substrate (conductive member) is joined to a lead member (connection member) that provides electrical conductivity to another conductive substrate (conductive member) by laser welding (see, for example, Patent Document 7).

[0012] Also, a technique is known in which a first terminal portion and a second terminal portion of a semiconductor device, which are arranged with an insulating member sandwiched therebetween, and a first supply terminal and a second supply terminal of a bus bar, which are arranged with an insulating member sandwiched therebetween, are joined by laser welding so that the first supply terminal portion is electrically connected to the first terminal portion and the second supply terminal portion is electrically connected to the second terminal portion (see, for example, Patent Document 8). [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-234694 [Patent Document 2] International Publication No. 2019 / 077866 Brochure [Patent Document 3] Patent Publication No. 2021-106235 [Patent Document 4] International Publication No. 2013 / 039099 Brochure [Patent Document 5] Japanese Patent Application Laid-Open No. 2008-66561 [Patent Document 6] Japanese Patent Application Laid-Open No. 2016-185067 [Patent Document 7] International Publication No. 2020 / 179369 Brochure [Patent Document 8] International Publication No. 2019 / 239771 Brochure Summary of the Invention [Problem to be solved by the invention]

[0014] Conventionally, with regard to laser welding, a technique has been known in which a protective member with a higher melting point than the metals to be laser welded is placed on the side of the overlapping metal opposite the side to which the laser light is incident, as in Patent Document 2, so that even if penetration occurs during welding, the protective member stops the progress of melting and prevents damage to the surrounding area due to the molten part.

[0015] However, when the terminal portion of the semiconductor module to which the capacitor is connected has a laminated structure in which a sheet-like insulating layer is sandwiched between positive and negative external terminals, as in Patent Document 3, the insulating layer is disposed on the back surface on the side irradiated with the laser, making it impossible to place a protective member. Therefore, when penetration occurs due to welding, the insulating layer is subjected to thermal stress, which changes the properties of the material in that portion, making it unable to maintain its original insulating performance and resulting in a decrease in withstand voltage.

[0016] The present invention has been made in consideration of these points, and aims to provide a semiconductor module in which, when a capacitor terminal is laser welded to a terminal portion having a laminated structure, heat from the molten portion is less likely to be transmitted to the insulating layer. [Means for solving the problem]

[0017] In one aspect of the present invention, a resin case and The aforementioned an insulating layer extending outward from the resin case; The aforementioned Extending outward from the resin case The aforementioned It is placed opposite the insulating layer and is The aforementioned At the position where it overlaps with the insulating layer The aforementioned In the thickness direction of the insulating layer The aforementioned a first external connection terminal having a non-contact portion spaced apart from the insulating layer; The insulating layer extends linearly inside the resin case, and the first external connection terminal has a first region disposed inside the resin case and facing the insulating layer, a second region disposed inside the resin case and in contact with the insulating layer, and a third region disposed inside the resin case and both ends of which are bent and connected to the first region and the second region. A semiconductor module is provided. Also provided is a semiconductor module comprising: a resin case; an insulating layer extending outward from the resin case; and a first external connection terminal extending outward from the resin case and positioned opposite the insulating layer, the first external connection terminal having a non-contact portion that overlaps with the insulating layer in a planar view and is spaced apart from the insulating layer in the thickness direction of the insulating layer, wherein a portion of the first external connection terminal is in contact with the insulating layer, and the non-contact portion is a recessed portion positioned on the surface of the first external connection terminal facing the insulating layer.

[0018] In another aspect of the present invention, a semiconductor device is provided, comprising the above-mentioned semiconductor module and a capacitor having a first terminal and a second terminal, wherein the first external connection terminal and the second terminal are conductively connected via a laser-welded portion of the first external connection terminal.

[0019] In yet another aspect of the present invention, a resin case and The aforementioned an insulating layer extending outward from the resin case; The aforementioned Extending outward from the resin case The aforementioned It is placed opposite the insulating layer and is The aforementioned At the position where it overlaps with the insulating layer The aforementioned In the thickness direction of the insulating layer The aforementioned a first external connection terminal having a non-contact portion spaced apart from the insulating layer; The aforementioned Insulation layer The aforementioned a semiconductor module including a second external connection terminal disposed on a surface opposite to the first external connection terminal; and a capacitor having a first terminal and a second terminal. The insulating layer extends linearly inside the resin case, and the first external connection terminal has a first region disposed inside the resin case and facing the insulating layer, a second region disposed inside the resin case and in contact with the insulating layer, and a third region disposed inside the resin case and both ends of which are bent and connected to the first region and the second region. A method for manufacturing a semiconductor device is provided. Also provided is a method for manufacturing a semiconductor device comprising: a semiconductor module including a resin case; an insulating layer extending outward from the resin case; a first external connection terminal extending outward from the resin case and arranged opposite the insulating layer, the first external connection terminal having a non-contact portion spaced apart from the insulating layer in the thickness direction of the insulating layer at a position overlapping the insulating layer in a planar view; and a second external connection terminal arranged on the surface of the insulating layer opposite the first external connection terminal; and a capacitor having a first terminal and a second terminal, wherein a portion of the first external connection terminal is in contact with the insulating layer and the non-contact portion is a recessed portion arranged on the surface of the first external connection terminal facing the insulating layer. child Rera The method for manufacturing a semiconductor device includes: The aforementioned First external connection terminal The aforementioned The method includes a step of electrically connecting the second terminal to the first terminal via the laser welding portion. [Effects of the Invention]

[0020] The semiconductor module having the above configuration has the advantage that the heat from the melted portion caused by laser welding is blocked by the non-contact portion and is not transmitted directly to the insulating layer, so that the insulating layer is not altered by the heat from the melted portion and the withstand voltage of the terminal portion is not reduced. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view showing a connection mechanism for a semiconductor module according to a first embodiment. [Figure 2] 1A and 1B are diagrams illustrating the terminal portion of a semiconductor module according to a first embodiment, in which (a) is a plan view of a first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip side in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of the welding portion of the terminal portion. [Figure 3] 10A and 10B are diagrams illustrating the effect, in which FIG. 10A shows the temperature distribution of the terminal portion when there is no non-contact portion, and FIG. 10B shows the temperature distribution of the terminal portion when there is a non-contact portion. [Figure 4] 10A and 10B are diagrams illustrating the terminal portion of a semiconductor module according to a second embodiment, in which (a) is a plan view of a first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip side in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of the welding portion of the terminal portion. [Figure 5] 10A and 10B are diagrams illustrating the terminal portion of a semiconductor module according to a third embodiment, in which (a) is a plan view of a first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip side in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of the welding portion of the terminal portion. [Figure 6] FIG. 10 is a cross-sectional view showing a connection mechanism for a semiconductor module according to a fourth embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a connection mechanism for a semiconductor module according to a fifth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing a modified example of the connection mechanism for the semiconductor module according to the fifth embodiment. [Figure 9] 13A to 13C are diagrams illustrating a method for manufacturing a semiconductor device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, taking as an example a semiconductor module having a laminated structure of a second external connection terminal, an insulating layer, and a first external connection terminal, and having a terminal portion to which a capacitor terminal is joined by laser welding.

[0023] [First embodiment] Fig. 1 is a cross-sectional view showing a connection mechanism of a semiconductor module according to a first embodiment. Fig. 2 is a diagram illustrating a terminal portion of a semiconductor module according to the first embodiment, where (a) is a plan view of a first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip end in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of a welded portion of the terminal portion. Fig. 3 is a diagram illustrating the effect, where (a) is a diagram showing the temperature distribution of the terminal portion when there is no non-contact portion, and (b) is a diagram showing the temperature distribution of the terminal portion when there is a non-contact portion.

[0024] 1, a semiconductor module 10 according to the first embodiment has a resin case 12 and terminal portions 14 extending to the outside from the resin case 12. The resin case 12 has a plurality of power devices that perform power conversion.

[0025] The terminal portion 14 has a second external connection terminal 16, an insulating layer 18, and a first external connection terminal 20, and has a laminated structure in which the insulating layer 18 is disposed on the second external connection terminal 16, and the first external connection terminal 20 is disposed on the insulating layer 18. The second external connection terminal 16, the insulating layer 18, and the first external connection terminal 20 of the terminal portion 14 can each have a shape that extends linearly inside the resin case 12, for example. The second external connection terminal 16 of the terminal portion 14 is connected to, for example, a negative power supply terminal of a circuit including a power device housed in the resin case 12, and the first external connection terminal 20 is connected to, for example, a positive power supply terminal of the circuit including the power device.

[0026] The capacitor 30 is an external element connected to the semiconductor module 10 and includes a resin case 32, a negative terminal (first terminal) 34, a sheet-like flexible insulating member 36, and a positive terminal (second terminal) 38. The negative terminal 34, the flexible insulating member 36, and the positive terminal 38 extend from the upper part of the resin case 32. After coming out of the resin case 32, the negative terminal 34 is bent to the right in the figure and extends parallel to the upper surface of the resin case 32. After coming out of the resin case 32, the positive terminal 38 is bent to the left in the figure at a position higher than the negative terminal 34 and extends parallel to the upper surface of the resin case 32.

[0027] Regarding the connection between the semiconductor module 10 and the capacitor 30, the second external connection terminal 16 of the terminal portion 14 of the semiconductor module 10 is directly joined to the negative terminal 34 of the capacitor 30, and the first external connection terminal 20 of the terminal portion 14 of the semiconductor module 10 is joined to the positive terminal 38 of the capacitor 30 via a flat connecting member 40, thereby achieving a conductive connection. The second external connection terminal 16 and the negative terminal 34 of the capacitor 30 are conductively connected by laser welding, whereby they are melted and solidified together at a welding portion 22, which is the connection portion. The positive terminal 38 of the capacitor 30 and the connecting member 40 are conductively connected by laser welding, whereby they are melted and solidified together at a welding portion 42, which is the connection portion, and the connecting member 40 and the first external connection terminal 20 of the terminal portion 14 are conductively connected by laser welding, whereby they are melted and solidified together at a welding portion 24, which is the connection portion.

[0028] The above laser welding is first performed at welding portion 22, then flexible insulating member 36 is bent to cover welding portion 22, and connecting member 40 is placed on first external connection terminal 20 and positive terminal 38, and then laser welding is performed at welding portion 42 and welding portion 24. As a result, the negative and positive conductors are arranged in parallel between semiconductor module 10 and capacitor 30, with insulating layer 18 and flexible insulating member 36 sandwiched between them, thereby reducing the inductance of the connecting portion.

[0029] The first external connection terminal 20 has a groove portion (non-contact portion) 26, which is a recess, on the surface opposite to the surface on which the welded portion 24, which is melted by laser welding, is located, i.e., on the surface in contact with the insulating layer 18. As shown in FIG. 2 , the groove portion 26 of the first external connection terminal 20 is formed on the surface directly below the welded portion 24, which is irradiated with laser light, and on the side in contact with the insulating layer 18, extending in a direction intersecting the direction extending from the resin case 12 (the vertical direction in FIG. 2( a) ). The groove portion 26 functions as a non-contact portion that does not come into contact with the insulating layer 18. The groove portion 26 forms an air layer directly below the welded portion 24 that does not come into direct contact with the insulating layer 18. Therefore, when the welded portion 24 becomes hotter than the melting point of the first external connection terminal 20 due to laser welding, the heat is blocked by the groove portion 26 and is not directly transmitted to the insulating layer 18, significantly reducing thermal damage to the insulating layer 18 directly below the welded portion 24. The first external connection terminals 20 are formed using plastic processing or cutting, in which a mold is pressed against the portions that will become the grooves 26 to plastically deform them and create a stepped shape. The first external connection terminals 20 have the grooves 26 formed inside their leading ends in the extension direction, so that the leading ends in the extension direction are in contact with the insulating layer 18. This is to hold down the insulating layer 18 at the leading ends in the extension direction. However, if the rigidity of the insulating layer 18 is sufficiently high, it is not necessary to hold down the insulating layer 18, so the non-contact portions of the first external connection terminals 20 can extend to the leading ends of the first external connection terminals 20.

[0030] Here, the connecting member 40 and the first external connection terminal 20 are made of a metal with excellent conductivity, such as copper or a copper alloy, and have a thickness of 0.8 mm to 3.0 mm. The depth of the groove 26 is preferably approximately up to one-third the thickness of the first external connection terminal 20, and is 0.05 mm to 1.0 mm, more preferably 0.1 mm. Depending on the type of laser light source, the connecting member 40, to which the laser light is irradiated, may be nickel-plated or have its surface roughened at least in the area of ​​the irradiated position to minimize reflection of the laser light at the irradiated position and absorb it as much as possible. The insulating layer 18 is, for example, a sheet-like insulating paper made of a wholly aromatic polyamide polymer, or a fluorine-based or polyimide-based resin material, with a thickness of approximately 0.2 mm to 0.5 mm, and has a heat-resistant temperature of approximately 300°C to 400°C.

[0031] 3 shows an example of the temperature distribution in the vicinity of the welded portion 24 when the connecting member 40, the first external connection terminal 20, and the insulating layer 18 are laser-welded together. That is, when the irradiation time is controlled so that the molten portion 50 penetrates the connecting member 40 and reaches the first external connection terminal 20, the melting point of copper is 1085°C, so the molten portion 50 reaches 1000°C or higher, and heat is transferred concentrically from the molten portion 50 to the surrounding area.

[0032] 3(a), when a first external connection terminal 20a that does not have a non-contact portion on the surface on the insulating layer 18 side is used, it can be seen that the insulating layer 18 reaches a temperature of 400° C. to 600° C. In this case, the insulating layer 18 is altered by the heat, and the withstand voltage may drop from 1000 V to 500 V, for example.

[0033] 3(b), when a first external connection terminal 20 having a groove 26 on the surface on the insulating layer 18 side is used, it can be seen that the temperature of the insulating layer 18 is kept at 200°C to 300°C in the illustrated example. Therefore, not only can a material with a low heat resistance temperature be used as the insulating layer 18, but the insulating layer is not subject to thermal deterioration, and therefore there is no deterioration in characteristics such as a decrease in withstand voltage.

[0034] [Second embodiment] 4A and 4B are diagrams illustrating the terminal portion of a semiconductor module according to a second embodiment, in which (a) is a plan view of the first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip side in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of the welding portion of the terminal portion.

[0035] The terminal portion 14a of the semiconductor module according to the second embodiment has a second external connection terminal 16, an insulating layer 18, and a first external connection terminal 20b. The second external connection terminal 16, the insulating layer 18, and the first external connection terminal 20b are stacked in this order. The second external connection terminal 16, the insulating layer 18, and the first external connection terminal 20b of the terminal portion 14a may each have a shape that extends linearly inside the resin case 12, for example.

[0036] The first external connection terminal 20b has a recess (non-contact portion) 26a that is oval in plan view on the surface on which the insulating layer 18 is located, directly below the welding portion 24. The recess 26a is formed, for example, by providing a step by crushing. The recess 26a may also be rectangular with steps along the entire periphery.

[0037] In this first external connection terminal 20b as well, the recess 26a provided directly below the welded portion 24 constitutes a non-contact portion that is not in direct contact with the insulating layer 18. Therefore, even if the welded portion 24 becomes hotter than the melting point of the first external connection terminal 20b due to laser welding, the heat is blocked by the air layer in the recess 26a and is not directly transmitted to the insulating layer 18, so the insulating layer 18 is not thermally damaged.

[0038] [Third embodiment] Figure 5 is a diagram illustrating the terminal portion of a semiconductor module according to the third embodiment, where (a) is a plan view of the first external connection terminal, (b) is a front view of the first external connection terminal as seen from the tip side in the extension direction, (c) is a side view of the first external connection terminal, and (d) is a cross-sectional view of the welding portion of the terminal portion.

[0039] The terminal portion 14b of the semiconductor module according to the third embodiment includes a second external connection terminal 16, an insulating layer 18, and a first external connection terminal 20c. The second external connection terminal 16, the insulating layer 18, and the first external connection terminal 20c are stacked in this order. The second external connection terminal 16, the insulating layer 18, and the first external connection terminal 20c of the terminal portion 14b may each have a shape that extends linearly inside the resin case 12. The first external connection terminal 20c of the terminal portion 14b may also have a shape that extends into the resin case 12 and is bent to contact the insulating layer 18 inside the resin case 12.

[0040] The first external connection terminal 20c has a protrusion 26b serving as a spacer near the area directly below the welded portion 24 on the surface of the insulating layer 18, forming a non-contact portion that does not contact the insulating layer 18. The protrusion 26b is fixed, for example, by attaching or embedding a cylindrical member on the surface of the first external connection terminal 20c opposite the welded portion 24. Alternatively, the protrusion 26b is preferably formed by half-blanking a copper plate by forcing a punch into the laser beam incident direction to extrude the protrusion onto the opposite surface. In the illustrated example, the first external connection terminal 20c has four protrusions 26b, but the number of protrusions 26b is not limited to four and may be one or more. The protrusions 26b may also be positioned farther from the resin case 12 than the area forming the non-contact portion.

[0041] For example, the protrusion 26b of the first external connection terminal 20c is disposed so that the distance from the resin case 12 to the protrusion 26b is longer than half the distance from the resin case 12 to the tip (end) of the first external connection terminal 20c in the extension direction. In other words, the protrusion 26b is disposed at a position farther away from the resin case 12 than half the distance from the resin case 12 to the tip of the first external connection terminal 20c in the extension direction.

[0042] In this first external connection terminal 20c, the surface opposite to the surface of the welded portion 24 is raised above the insulating layer 18 by the protrusion 26b, and therefore forms a non-contact portion that is not in direct contact with the insulating layer 18. Therefore, even if the welded portion 24 becomes hotter than the melting point of the first external connection terminal 20c due to laser welding, the heat is blocked by the air layer that is created when the first external connection terminal 20c is raised above the insulating layer 18. As a result, the heat from the laser welding is not directly transmitted to the insulating layer 18, and the insulating layer 18 is not thermally damaged.

[0043] In the terminal portion 14b of the semiconductor module according to the third embodiment, the first external connection terminal 20c may have, in addition to the protrusion 26b, a groove 26 directly below the welding portion 24, as in the example described in the first embodiment, or a recess 26a directly below the welding portion 24, as in the example described in the second embodiment. By adopting a configuration in which the groove 26 or the recess 26a is combined with the protrusion 26b in the first external connection terminal 20c, a space is formed directly below the welding portion 24, the height of which from the insulating layer 18 is higher than the height of the protrusion 26b by the depth of the groove 26 or the recess 26a. As a result, a larger space is formed directly below the welding portion 24 than when the first external connection terminal 20c, which faces the insulating layer 18 via the protrusion 26b, is formed at a height relative to the insulating layer 18 unchanged. Therefore, the effect of insulating the heat from the welded portion 24 during laser welding is enhanced, and the heat is more effectively prevented from being transmitted to the insulating layer 18.

[0044] [Fourth embodiment] Fig. 6 is a cross-sectional view showing a connection mechanism for a semiconductor module according to a fourth embodiment. In Fig. 6, components that are the same as or equivalent to those shown in Fig. 1 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0045] A semiconductor module 10a according to the fourth embodiment has a resin case 12a. Compared to the resin case 12 of the first embodiment, the resin case 12a is configured such that a surface area 16a directly below the welded portion 22 is not in contact with the surface of the second external connection terminal 16 opposite to the surface that is joined to the negative electrode terminal 34 of the capacitor 30. To achieve this, the second external connection terminal 16 protrudes outward from the outer periphery of the resin case 12a in a plan view by the length of the surface area 16a directly below the welded portion 22.

[0046] Since the resin case 12a is formed so as to avoid the surface region 16a directly below the welding portion 22, when the negative electrode terminal 34 of the capacitor 30 is laser welded to the second external connection terminal 16, heat is not transferred to the resin case 12a, and deformation or discoloration of the resin case 12a is prevented.

[0047] The resin case 12a is molded integrally with the terminal portion 14 by insert molding using a thermoplastic resin. The thermoplastic resin may be, for example, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polybutylene succinate (PBS) resin, polyamide (PA) resin, or acrylonitrile butadiene styrene (ABS) resin. The heat resistance temperature of these resins is approximately 300°C to 400°C.

[0048] 6 shows an example in which the resin case 12a employs the terminal portion 14 having the first external connection terminal 20 with the groove portion 26 as described in the first embodiment, but the form of the terminal portion employed in the resin case 12a is not limited to that shown in Fig. 6. The resin case 12a may employ the terminal portion 14a having the first external connection terminal 20b with the recess portion 26a as described in the second embodiment, or the terminal portion 14b having the first external connection terminal 20c with the protrusion portion 26b as described in the third embodiment, or a terminal portion that combines the groove portion 26 or the recess portion 26a with the protrusion portion 26b. Even when such terminal portions 14a, 14b, etc. are employed in the resin case 12a, by configuring the surface area of ​​the second external connection terminal 16 directly below the portion where the negative electrode terminal 34 of the capacitor 30 is laser welded to protrude outside the resin case 12a, it is possible to prevent the heat generated during laser welding of the negative electrode terminal 34 from being transferred to the resin case 12a, and to prevent deformation or discoloration of the resin case 12a.

[0049] [Fifth embodiment] Fig. 7 is a cross-sectional view showing a connection mechanism for a semiconductor module according to a fifth embodiment. In Fig. 7, components that are the same as or equivalent to those shown in Fig. 1 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0050] 7, a semiconductor module 10b according to the fifth embodiment includes a resin case 12b and terminal portions 14c partially extending outward from the resin case 12b. A plurality of power devices that perform power conversion are housed within the resin case 12b.

[0051] The terminal portion 14c has a second external connection terminal 16b, an insulating layer 18a, and a first external connection terminal 20d, and has a laminated structure in which the insulating layer 18a is disposed on the second external connection terminal 16b and the first external connection terminal 20d is disposed on the insulating layer 18a. The second external connection terminal 16b of the terminal portion 14c is connected to, for example, a negative power supply terminal of a circuit including a power device housed in the resin case 12b. The first external connection terminal 20d of the terminal portion 14c is connected to, for example, a positive power supply terminal of a circuit including a power device housed in the resin case 12b.

[0052] Here, the second external connection terminal 16b of the terminal portion 14c is a flat plate with a portion sealed within the resin case 12b and disposed therein, and another portion extending outward from the resin case 12b. The second external connection terminal 16b extends linearly from the outside to the inside of the resin case 12b. The second external connection terminal 16b has a welding portion 22 at a portion disposed outside the resin case 12b, where the negative electrode terminal 34 of the capacitor 30 is welded by laser welding. The second external connection terminal 16b is made of a metal with excellent conductivity, such as copper or a copper alloy.

[0053] The insulating layer 18a of the terminal portion 14c is a sheet-like layer, with a portion sealed within the resin case 12b and the other portion extending outward from the resin case 12b. The insulating layer 18a extends linearly from the outside to the inside of the resin case 12b. The insulating layer 18a is made of insulating paper made of a wholly aromatic polyamide polymer, a fluorine-based resin, a polyimide-based resin, or the like.

[0054] The first external connection terminal 20d of the terminal portion 14c has a shape in which a portion is sealed within the resin case 12b and disposed therein, and another portion extends outward from the resin case 12b. The portion of the first external connection terminal 20d disposed within the resin case 12b includes a first region 20d1 disposed opposite the insulating layer 18a, a second region 20d2 in contact with the insulating layer 18a, and a third region 20d3 whose ends are bent and connected to the first region 20d1 and the second region 20d2. The portion of the first external connection terminal 20d disposed outside the resin case 12b includes a welding region 24 to which a linking member 40 connected to the positive terminal 38 of the capacitor 30 is welded by laser welding. The first external connection terminal 20d is made of a metal with excellent conductivity, such as copper or a copper alloy.

[0055] The portion of the first external connection terminal 20d disposed inside the resin case 12b has a shape bent at a third region 20d3 connected to the first region 20d1 and the second region 20d2, which are spaced apart from and face the insulating layer 18a. The bend shape of the first external connection terminal 20d inside the resin case 12b does not necessarily have to be a crank shape bent twice at 90° as shown in FIG. 7, as long as the second region 20d2 and the third region 20d3 are bent so that the second region 20d2 and the third region 20d3 are spaced apart from and face the insulating layer 18a. In the cross-sectional view shown in FIG. 7, the angle between the second region 20d2 and the third region 20d3 is not limited to 90° and may be an acute angle or an obtuse angle. 7, the angle between the third region 20d3 and the first region 20d1 is not limited to 90° and may be an acute angle or an obtuse angle. Furthermore, the number of bends in the first external connection terminal 20d is not limited to two and may be three or more.

[0056] The portion of the first external connection terminal 20d located outside the resin case 12b is connected to a first region 20d1 located inside the resin case 12b, facing the insulating layer 18a at a distance, and extends outward from the resin case 12b. The first external connection terminal 20d extending outward from the resin case 12b is arranged parallel to and facing the second external connection terminal 16b and the insulating layer 18a thereon, at a distance. A space (non-contact portion) 26c is provided between the first external connection terminal 20d extending outward from the resin case 12b and the insulating layer 18a above the second external connection terminal 16b. In the semiconductor module 10b, the entire surface of the portion of the first external connection terminal 20d extending outward from the resin case 12b facing the insulating layer 18a constitutes a non-contact portion where the first external connection terminal 20d does not come into contact with the insulating layer 18a.

[0057] The distance between the first external connection terminal 20d and the second external connection terminal 16b, which extend outward from the resin case 12b, in the thickness direction of the insulating layer 18a or the height direction of the space 26c is set to, for example, a range of 0.05 mm to 2.0 mm. During operation of the semiconductor module 10b, the first external connection terminal 20d and the second external connection terminal 16b, which face each other and are spaced apart in parallel via the insulating layer 18a and the space 26c, have opposite polarities, thereby reducing inductance. If the distance between the first external connection terminal 20d and the second external connection terminal 16b exceeds 2.0 mm, the inductance reduction effect may be reduced or may not be achieved. If the distance between the first external connection terminal 20d and the second external connection terminal 16b is less than 0.05 mm, the heat insulation effect of the space 26c during laser welding, as described below, may be reduced or may not be achieved.

[0058] The insulating layer 18a provided between the first external connection terminal 20d and the second external connection terminal 16b extending outward from the resin case 12b is shaped to ensure an insulation distance (creepage distance) via the insulating layer 18a between the first external connection terminal 20d and the second external connection terminal 16b. For example, if the distance in the thickness direction of the insulating layer 18a or the height direction of the space 26c between the first external connection terminal 20d and the second external connection terminal 16b is within a distance range that achieves the above-described inductance reduction effect, the insulating layer 18a is shaped so that its tip in the extension direction is located closer to the tip in the extension direction of the second external connection terminal 16b than the tip in the extension direction of the first external connection terminal 20d, as shown in FIG. The positions of the leading ends in the extension direction of the first external connection terminal 20d and the insulating layer 18a are set so as to ensure a sufficient insulation distance between the leading end in the extension direction of the first external connection terminal 20d and the second external connection terminal 16b exposed outside the leading end in the extension direction of the insulating layer 18a. Note that when setting the shape of the insulating layer 18a, the insulation distance in the front and rear directions of the paper in FIG. 7 is taken into consideration in addition to the insulation distance in the cross-sectional view shown in FIG.

[0059] The first external connection terminal 20d of the terminal portion 14c is formed by bending a flat plate-shaped member by plastic processing using a mold or the like. The terminal portion 14c includes a flat plate-shaped second external connection terminal 16b, a sheet-like insulating layer 18a, and a folded first external connection terminal 20d, which are stacked in this order so that the second external connection terminal 16b contacts one surface of the insulating layer 18a and one ends of the second region 20d2 and the third region 20d3 of the first external connection terminal 20d contact the other surface of the insulating layer 18a. The terminal portion 14c is molded integrally with the resin case 12b by insert molding the second external connection terminal 16b, the insulating layer 18a, and the first external connection terminal 20d stacked in this order using a resin material such as PPS resin used for the resin case 12b.

[0060] In connection between the semiconductor module 10b and the capacitor 30 as described above, the second external connection terminal 16b of the terminal portion 14c of the semiconductor module 10b is electrically connected by being directly joined to the negative terminal 34 of the capacitor 30. The first external connection terminal 20d of the terminal portion 14c of the semiconductor module 10b is electrically connected to the positive terminal 38 of the capacitor 30 by being joined via a flat-plate-shaped connecting member 40.

[0061] In the conductive connection between the second external connection terminal 16b of the terminal portion 14c of the semiconductor module 10b and the negative terminal 34 of the capacitor 30, the negative terminal 34 is placed on the second external connection terminal 16b, and laser light is irradiated onto the welding portion 22 from the side of the negative terminal 34, thereby laser welding the negative terminal 34 and the second external connection terminal 16b together. The negative terminal 34 and the second external connection terminal 16b are conductively connected by being melted and solidified together at the welding portion 22, which is the connection portion, by laser welding. In other words, the negative terminal 34 and the second external connection terminal 16b are conductively connected via the welding portion 22 by laser welding.

[0062] In the conductive connection between the first external connection terminal 20d of the terminal portion 14c of the semiconductor module 10b and the positive terminal 38 of the capacitor 30 via the connecting member 40, the connecting member 40 is placed on the first external connection terminal 20d extending outward from the resin case 12b (the side opposite to the space 26c) and on the positive terminal 38. Then, a laser beam is irradiated onto the welding portion 42 from the connecting member 40 side, thereby laser welding the connecting member 40 and the positive terminal 38. Furthermore, a laser beam is irradiated onto the welding portion 24 from the connecting member 40 side, thereby laser welding the connecting member 40 and the first external connection terminal 20d. The order of laser welding the welding portion 42 and the welding portion 24 does not matter. The connecting member 40 and the positive electrode terminal 38 are electrically connected by being laser-welded to each other at a welding portion 42, which is a connection portion, and the connecting member 40 and the first external connection terminal 20d are electrically connected by being laser-welded to each other at a welding portion 24, which is a connection portion. That is, the connecting member 40 and the positive electrode terminal 38 are electrically connected to each other via the welding portion 42 by laser welding, and the connecting member 40 and the first external connection terminal 20d are electrically connected to each other via the welding portion 24 by laser welding.

[0063] In the semiconductor module 10b, a space 26c is provided on the side of the first external connection terminal 20d extending outward from the resin case 12b opposite to the side on which the welded portion 24, which will be melted by laser welding, is located, i.e., on the side facing the second external connection terminal 16b and the insulating layer 18a thereon. This space 26c is formed by bending the first external connection terminal 20d in the above-described shape, i.e., by bending it inside the resin case 12b so as to be away from the insulating layer 18a and extending it outward from the resin case 12b. In the semiconductor module 10b, the first external connection terminal 20d extending outward from the resin case 12b, the space 26c sandwiched between the first external connection terminal 20d and the insulating layer 18a, the insulating layer 18a, and the second external connection terminal 16b are arranged directly below the welded portion 24, which will be laser-welded to the connecting member 40.

[0064] In this manner, in the semiconductor module 10b, a space 26c is provided directly below the welded portion 24 between the first external connection terminals 20d extending outward from the resin case 12b and the insulating layer 18a, preventing the first external connection terminals 20d extending outward from the resin case 12b from contacting the insulating layer 18a. The space 26c functions as a non-contact portion that prevents the first external connection terminals 20d extending outward from the resin case 12b from contacting the insulating layer 18a. The space 26c forms an air layer directly below the welded portion 24, preventing the first external connection terminals 20d from directly contacting the insulating layer 18a. Therefore, when the welded portion 24 becomes hotter than the melting point of the first external connection terminals 20d due to laser welding, the heat is blocked by the space 26c and is not directly transferred to the insulating layer 18a, significantly reducing thermal damage to the insulating layer 18a directly below the welded portion 24. This effectively prevents the insulating layer 18a from being altered by heat and the breakdown voltage of the terminal portion 14c from decreasing. In addition, because the insulating layer 18a is prevented from being altered by heat, it becomes possible to use an insulating layer 18a with a low heat resistance temperature.

[0065] By employing the terminal portion 14c having the above-described configuration, a high-quality, high-performance semiconductor module 10b and a high-quality, high-performance semiconductor device in which such semiconductor module 10b and capacitor 30 are connected can be realized.

[0066] 8 is a cross-sectional view showing a modified example of the connection mechanism for the semiconductor module according to the fifth embodiment. In this Fig. 8, components that are the same as or equivalent to those shown in Fig. 1 and Fig. 7 are given the same reference numerals, and detailed description thereof will be omitted.

[0067] The semiconductor module 10c shown in FIG. 8 differs from the semiconductor module 10a (FIG. 6) described in the fourth embodiment in that a surface region 16a directly below the welding portion 22, which is the surface of the second external connection terminal 16b opposite to the surface bonded to the negative terminal 34 of the capacitor 30, is configured not to come into contact with the resin case 12b. That is, as in the semiconductor module 10c shown in FIG. 8, the second external connection terminal 16b may be provided so as to protrude beyond the outer periphery of the resin case 12b. In this way, the resin case 12b is formed so as to avoid the area directly below the welding portion 22. Therefore, when the negative terminal 34 of the capacitor 30 is laser-welded to the second external connection terminal 16b, heat transfer to the resin case 12b can be avoided, preventing deformation or discoloration of the resin case 12b.

[0068] In accordance with the example of the fifth embodiment, the second external connection terminal 16 and insulating layer 18 of the terminal portion 14b (FIG. 5) described in the third embodiment may each be shaped to extend linearly inside the resin case 12, and the first external connection terminal 20c may be shaped to extend inside the resin case 12 and bend to contact the insulating layer 18 inside the resin case 12. In addition, in the semiconductor modules 10b and 10c (FIGS. 7 and 8) according to the fifth embodiment, the first external connection terminal 20d extending outside the resin case 12b may be provided with a protrusion 26b that serves as a spacer between the first external connection terminal 20d and the insulating layer 18a, in accordance with the example described in the third embodiment.

[0069] In addition, in the semiconductor module 10b and the semiconductor module 10c (Figures 7 and 8) according to the fifth embodiment, the first external connection terminal 20d extending outside the resin case 12b may be provided with a groove portion 26 as described in the first embodiment above, or a recessed portion 26a as described in the second embodiment above, or a combination of the groove portion 26 or the recessed portion 26a and the protrusion portion 26b.

[0070] [Sixth embodiment] Here, an example of a method for manufacturing the above-described semiconductor device will be described as a sixth embodiment.

[0071] FIG. 9 is a diagram illustrating a method for manufacturing a semiconductor device according to the sixth embodiment. In manufacturing a semiconductor device, a semiconductor module having a configuration as described in the first to fifth embodiments, for example, semiconductor module 10, semiconductor module 10a, semiconductor module 10b, semiconductor module 10c, etc., is prepared (step S1). Furthermore, a capacitor 30 as described above is prepared to be connected to the semiconductor module 10, etc. prepared in step S1 (step S2). Furthermore, a coupling member 40 as described above is prepared to be used to connect the semiconductor module 10, etc. prepared in step S1 to the capacitor 30 prepared in step S2 (step S3). The order of steps S1 to S3 does not matter.

[0072] After preparing the semiconductor module 10 or the like, the capacitor 30, and the connecting member 40, first, the second external connection terminals 16, 16b of the semiconductor module 10 or the like and the negative terminal 34 of the capacitor 30 are laser-welded at the welding portion 22 (step S4). At this time, the negative terminal 34 is placed on the second external connection terminals 16, 16b, and laser light is irradiated onto the welding portion 22 from the side of the negative terminal 34. As a result, the negative terminal 34 and the second external connection terminals 16, 16b are laser-welded to form a conductive connection.

[0073] After the negative electrode terminal 34 and the second external connection terminals 16, 16b are laser-welded together, the flexible insulating member 36 of the capacitor 30 is bent so as to cover the welded portion 22 (step S5).

[0074] Next, the coupling member 40 is placed on the first external connection terminals 20, 20b, 20c, 20d of the semiconductor module 10 etc. and the positive terminal 38 of the capacitor 30 (step S6).

[0075] Then, the first external connection terminals 20, 20b, 20c, and 20d are laser-welded to one end of the connecting member 40 placed thereon at welding position 24 (step S7), and the positive electrode terminal 38 is laser-welded to the other end of the connecting member 40 placed thereon at welding position 42 (step S8). At this time, laser light is irradiated onto welding position 24 and welding position 42 from the connecting member 40 side. As a result, the connecting member 40 and the first external connection terminals 20, 20b, 20c, and 20d are laser-welded to be electrically connected, and the connecting member 40 and the positive electrode terminal 38 are laser-welded to be electrically connected. The order of steps S7 and S8 does not matter.

[0076] For example, a semiconductor device is manufactured using a method such as steps S1 to S8. In manufacturing a semiconductor device, as described above, a non-contact portion is provided directly below the welded portion 24 between the first external connection terminals 20, 20b, 20c, and 20d and the insulating layer 18, 18a by the groove 26, the recess 26a, the protrusion 26b, the space 26c, etc. Therefore, an air layer is formed directly below the welded portion 24, preventing the first external connection terminals 20, 20b, 20c, and 20d from coming into direct contact with the insulating layer 18, 18a. Therefore, when the welded portion 24 becomes hotter than the melting point of the first external connection terminals 20, 20b, 20c, and 20d due to laser welding, the air layer blocks the heat and prevents it from being directly transmitted to the insulating layer 18, 18a. This reduces thermal damage to the insulating layer 18, 18a directly below the welded portion 24. This prevents thermal deterioration of the insulating layer 18, 18a and the resulting decrease in breakdown voltage. A high-quality, high-performance semiconductor device is realized in which the high-quality, high-performance semiconductor module 10 and the like are connected to the capacitor 30. [Explanation of symbols]

[0077] 10, 10a, 10b, 10c semiconductor module 12, 12a, 12b Resin case 14,14a,14b,14c terminal section 16, 16b Second external connection terminal 16a surface area 18,18a Insulating layer 20, 20a, 20b, 20c, 20d First external connection terminal 20d1 1st area 20d2 2nd area 20d3 3rd area 22,24 Welding parts 26 Groove (non-contact part) 26a Recess (non-contact part) 26b Protrusion 26c Space (non-contact part) 30 capacitors 32 Resin case 34 Negative terminal (first terminal) 36 Flexible insulating member 38 Positive terminal (second terminal) 40 Connecting member 42 Welded parts 50 Melted part

Claims

1. A resin case and an insulating layer extending outward from the resin case; a first external connection terminal extending outward from the resin case and disposed opposite the insulating layer, the first external connection terminal having a non-contact portion spaced apart from the insulating layer in a thickness direction of the insulating layer at a position overlapping the insulating layer in a plan view; Equipped with the insulating layer extends linearly inside the resin case, a semiconductor module, wherein the first external connection terminal has a first region that is arranged inside the resin case and facing the insulating layer, a second region that is arranged inside the resin case and in contact with the insulating layer, and a third region that is arranged inside the resin case and has both ends bent and connected to the first region and the second region.

2. A resin case and an insulating layer extending outward from the resin case; a first external connection terminal extending outward from the resin case and disposed opposite the insulating layer, the first external connection terminal having a non-contact portion spaced apart from the insulating layer in a thickness direction of the insulating layer at a position overlapping the insulating layer in a plan view; Equipped with a portion of the first external connection terminal contacting the insulating layer; The non-contact portion is a recessed portion disposed on a surface of the first external connection terminal facing the insulating layer.

3. 3. The semiconductor module according to claim 2, wherein the recess extends in a direction intersecting a direction extending from the resin case on a surface of the first external connection terminal that is in contact with the insulating layer.

4. The semiconductor module according to claim 3 , wherein the recess has an oval or rectangular shape in a plan view.

5. The semiconductor module according to claim 1 , wherein the first external connection terminal has at least one protrusion on a surface near the non-contact portion.

6. The semiconductor module according to claim 5 , wherein the distance from the resin case to the protrusion is longer than half the distance from the resin case to the end of the first external connection terminal.

7. 2 . The semiconductor module according to claim 1 , wherein the entire surface of the first external connection terminal on the insulating layer side of the portion extending outward from the resin case is the non-contact portion.

8. The semiconductor module according to claim 1 , further comprising a second external connection terminal on a surface of the insulating layer opposite to the first external connection terminal.

9. The semiconductor module according to claim 8 , wherein the second external connection terminals protrude outward beyond an outer periphery of the resin case in a plan view.

10. The semiconductor module according to claim 1 , a capacitor having a first terminal and a second terminal; The semiconductor device, wherein the first external connection terminal and the second terminal are electrically connected via a laser-welded portion of the first external connection terminal.

11. a flat-plate-shaped connecting member having one end connected to the first external connection terminal and the other end connected to the second terminal; a laser welding portion is provided at a connection portion between the first external connection terminal and the coupling member and at a connection portion between the second terminal and the coupling member; The semiconductor device according to claim 10.

12. The semiconductor module according to claim 8 or 9; a capacitor having a first terminal and a second terminal; the second external connection terminal is connected to the first terminal, and a laser welded portion is provided at a connection portion between the second external connection terminal and the first terminal.

13. a semiconductor module including: a resin case; an insulating layer extending outward from the resin case; a first external connection terminal extending outward from the resin case and disposed opposite the insulating layer, the first external connection terminal having a non-contact portion spaced apart from the insulating layer in a thickness direction of the insulating layer at a position overlapping the insulating layer in a plan view; and a second external connection terminal disposed on a surface of the insulating layer opposite to the first external connection terminal; a capacitor having a first terminal and a second terminal; Equipped with the insulating layer extends linearly inside the resin case, a method for manufacturing a semiconductor device, wherein the first external connection terminal has a first region disposed inside the resin case and facing the insulating layer, a second region disposed inside the resin case and in contact with the insulating layer, and a third region disposed inside the resin case and having both ends bent and connected to the first region and the second region, A method for manufacturing a semiconductor device, comprising: electrically connecting the first external connection terminal and the second terminal via a laser welded portion.

14. a semiconductor module including: a resin case; an insulating layer extending outward from the resin case; a first external connection terminal extending outward from the resin case and disposed opposite the insulating layer, the first external connection terminal having a non-contact portion spaced apart from the insulating layer in a thickness direction of the insulating layer at a position overlapping the insulating layer in a plan view; and a second external connection terminal disposed on a surface of the insulating layer opposite to the first external connection terminal; a capacitor having a first terminal and a second terminal; Equipped with a portion of the first external connection terminal contacting the insulating layer; In a method for manufacturing a semiconductor device, the non-contact portion is a recessed portion disposed on a surface of the first external connection terminal facing the insulating layer, A method for manufacturing a semiconductor device, comprising: electrically connecting the first external connection terminal and the second terminal via a laser welded portion.

15. 15. The method for manufacturing a semiconductor device according to claim 13, wherein the laser welding portion that conductively connects the first external connection terminal and the second terminal is formed by irradiating a laser from the side opposite the non-contact portion of the first external connection terminal.

16. The method for manufacturing a semiconductor device according to claim 13 , further comprising the step of electrically connecting the second external connection terminal and the first terminal via a laser welded portion.

17. the semiconductor device includes a flat-plate-shaped connecting member, one end of which is connected to the first external connection terminal and the other end of which is connected to the second terminal; a step of laser welding a connection portion between the first external connection terminal and the coupling member and a connection portion between the second terminal and the coupling member, respectively; The method for manufacturing a semiconductor device according to any one of claims 13 to 16.

Images