JP7528481B2 - Semiconductor module and manufacturing method thereof - Google Patents

Description

The present invention relates to a semiconductor module and a manufacturing method thereof, in particular, a power semiconductor module and a manufacturing method thereof.

Power semiconductor modules are widely used in fields that require efficient power conversion. Examples include the renewable energy field, such as solar power generation and wind power generation, which have been attracting attention in recent years, the automotive field, such as hybrid cars and electric cars, and the railway field, such as vehicles.

These power semiconductor modules have built-in switching elements and diodes, and wide band gap semiconductors such as Si (silicon) semiconductors and SiC (silicon carbide) semiconductors are used for the power semiconductor elements. SiC semiconductors have features such as higher voltage resistance, higher heat resistance, and lower loss than Si semiconductors, and their use in power semiconductor modules makes it possible to miniaturize the device and reduce loss. In this case, the power semiconductor elements are sealed with a sealant containing epoxy resin, which has excellent moisture resistance, heat resistance, and mechanical properties, and since the insulation and shape can be guaranteed, a caseless and/or baseless structure can be used.

However, with a caseless, baseless structure, when the module size increases to accommodate a larger rated current, there are problems with stress caused by the sealing material and reduced insulation performance due to internal resin not being filled (voids, etc.), making it difficult to increase capacity.

In addition, it is possible to increase capacity by reducing the module size, making the unit with a smaller current capacity per module, and connecting multiple units with bus bars or the like. However, in order to increase the voltage resistance of a power semiconductor module, the insulation distance must be increased, making it difficult to reduce the size of the entire module.

To solve the above problem, it has been proposed to arrange semiconductor units sealed with a sealant on a base, form a recess on the top surface of the unit, join the external terminal pins of the unit to the external terminal bus bars, and fill the joints with resin (Patent Document 1). Solder joining and laser welding have been proposed as joining methods, but there are issues with joining within the recess, such as it being difficult to insert a soldering iron and laser light.

JP 2018-29141 A

The present invention was made in consideration of the above problems, and aims to provide a semiconductor module and a manufacturing method thereof that allows easy connection between an external terminal block and an external terminal bus bar and has highly reliable connections.

A semiconductor module according to an embodiment of the present invention includes a laminated substrate on which a semiconductor element is mounted,
an external terminal block provided on a mounting surface of the laminated board;
an external terminal bus bar electrically connected to the external terminal block;
a first sealing portion made of a resin in which at least the laminated substrate, the semiconductor element, and the external terminal block are embedded;
the external terminal bus bar has a connection portion formed by bending a main body portion of the external terminal bus bar,
the external terminal block has a connection surface exposed from the first sealing portion;
The connection portion of the external terminal bus bar is joined to the connection surface of the external terminal block by ultrasonic bonding.

A manufacturing method according to another embodiment of the present invention includes the steps of mounting a semiconductor element on a laminated substrate;
providing an external terminal block on a mounting surface of the laminated board;
a step of forming a first sealing portion by embedding at least the laminated substrate, the semiconductor element, and the external terminal block in a resin;
and electrically connecting the external terminal bus bars to the external terminal block.
the external terminal bus bar has a connection portion formed by bending a main body portion of the external terminal bus bar,
The step of forming the first sealing portion includes forming the first sealing portion such that a connection surface of the external terminal block is exposed from the first sealing portion;
The connecting step includes ultrasonically bonding an external terminal bus bar to the connection surface of the external terminal block exposed from the first sealing portion.

The semiconductor module according to the present invention can easily connect the external terminal block and the external terminal bus bar, and can provide a semiconductor module and a manufacturing method thereof that have highly reliable connections.

FIG. 1 is a conceptual diagram showing a cross-sectional structure of a power semiconductor module according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view that illustrates a schematic configuration of an external terminal bus bar. FIG. 3 is an enlarged cross-sectional view showing a joint between a connection portion of an external terminal bus bar and an external terminal block. FIG. 4 is a cross-sectional view showing a first modified example of the connection portion of the external terminal bus bar of the above embodiment. FIG. 5 is a cross-sectional view showing a second modified example of the connection portion of the external terminal bus bar of the above embodiment.

The following describes embodiments of the present invention with reference to the drawings. These may be modified and combined as appropriate. In the following description and accompanying drawings, substantially the same or equivalent parts are denoted by the same reference numerals. Note that the present invention is not limited to the embodiments described below.

[First embodiment]
1 is a conceptual diagram showing a cross-sectional structure of a power semiconductor module 10 according to a first embodiment of the present invention. As shown in Fig. 1, a power semiconductor element 1 is mounted on a laminated substrate 2 via a first bonding layer 3 such as solder.

An implant-type printed circuit board 6 equipped with implant pins 5 is attached to the top surface of the power semiconductor element 1 via a bonding layer (not shown) such as solder. An external terminal block 4 is erected on the top surface of the laminated substrate 2 via a bonding layer (not shown) such as solder.

The laminated substrate 2, the semiconductor element 1, the implant pin 5, and the printed circuit board 6 are embedded in a first sealing portion 8 made of a first sealing material. In this specification, the members embedded in the first sealing portion 8 and insulated and sealed are referred to as the members to be sealed.

The external terminal block 4 is embedded in the first sealing portion 8, but its upper surface is exposed from the first sealing portion 8, and this exposed surface of the external terminal block 4 serves as a connection surface 4A. The first sealing portion 8 has a flat surface (upper surface). The upper surface of the first sealing portion 8 may be flat except for the exposed portion of the external terminal block 4. The connection surface 4A of the external terminal block 4 is joined to the external terminal bus bar 7 and electrically connected.
Specifically, the first sealing portion surface may be flat with the tip (exposed portion) of the external terminal block, or the tip of the external terminal block may protrude from the first sealing portion surface. In this case, as shown in FIG. 3, the joining surface 7C of the external terminal bus bar may be wider (wider area), which makes it easier to position during ultrasonic bonding and allows for a larger joining area. The protrusion amount of the external terminal block is preferably 1 mm to 5 mm. On the other hand, the first sealing portion surface may protrude from the tip (exposed portion) of the external terminal block, and the tip of the external terminal block may be recessed. In this case, the joining surface 7C of the external terminal bus bar fits into the recess, making it easier to position, but the joining area is smaller than in the former case. The protrusion amount of the first sealing portion 8 is preferably 1 mm to 5 mm.

The laminated substrate 2 is joined to the base 11 via a second joining layer 11A such as solder. The case lid 12 is mounted on the base 11 via an adhesive or the like (not shown). A second sealing portion 9 made of a second sealing material is provided within the base 11 and the case lid 12 so as to cover at least the joint between the external terminal block 4 and the external terminal bus bar 7. The case lid 12 is made up of a case 12A made up of four sidewalls and a lid 12B covering the upper part of the case 12A. The base 11 and the case lid 12 house the first sealing portion 8 and the second sealing portion 9 in which the sealed member is embedded.

In this specification, the terms "upper surface" and "lower surface" are relative terms referring to the top and bottom in the drawings for the purpose of explanation, and are not intended to limit the top and bottom in relation to the manner of use of the power semiconductor module, etc.

The power semiconductor element 1 is a power chip such as an IGBT or a diode chip, and various Si devices, SiC devices, GaN devices, etc. may be used. A combination of these devices may also be used. For example, a hybrid module using a Si-IGBT and a SiC-SBD may be used. The number of power semiconductor elements 1 mounted is not limited to the form shown in the figure, and multiple power semiconductor elements 1 may also be mounted.

The laminated substrate 2 is composed of an insulating substrate 22, a second conductive plate 21 formed on one surface (lower surface or bottom surface) of the insulating substrate 22, and a first conductive plate 23 formed on the other surface. The insulating substrate 22 can be made of a material with excellent electrical insulation and thermal conductivity.

Examples of materials for the insulating substrate 22 include _Al2O3 , AlN, SiN, resins with excellent thermal conductivity, etc. In particular, for high-voltage applications, a material that has both electrical insulation and thermal conductivity is preferable, and _AlN and SiN can be used, but are not limited to these.

The second conductive plate 21 and the first conductive plate 23 can be made of metal materials such as Cu and Al, which have excellent workability. In addition, Cu and Al that have been treated with Ni plating or other treatments for the purpose of rust prevention may also be used. Methods for disposing the conductive plates 21 and 23 on the insulating substrate 22 include a direct copper bonding method and an active metal brazing method.

The first bonding layer 3 can be formed using lead-free solder. For example, Sn-Ag-Cu based, Sn-Sb based, Sn-Sb-Ag based, Sn-Cu based, Sn-Sb-Ag-Cu based, Sn-Cu-Ni based, Sn-Ag based, etc. can be used, but are not limited to these.

The printed circuit board 6 (wiring board) serves to electrically connect elements to elements and elements to external terminals, and may be a polyimide film board or an epoxy film board with a conductive layer of Cu, Al, or the like formed thereon. The implant pin 6 may be a copper pin made of copper. The conductive layer of the printed circuit board 7 and the implant pin 5 may be Cu or Al that has been treated with Ni plating or the like for the purpose of rust prevention, or may be treated with Sn plating or the like for the purpose of bonding.

When multiple power semiconductor elements 1 are provided, the printed circuit board 6 and implant pin 5 electrically connect the power semiconductor elements 1 to each other. Alternatively, the printed circuit board 6 and implant pin 5 electrically connect the power semiconductor elements 1 to the laminated substrate 2. The implant pin 5 and the laminated substrate 2 or the power semiconductor elements 1 can be joined by the first solder joint layer 3 described above. Note that a lead frame may be used instead of the implant pin 5.

The external terminal block 4, which is joined by the first joining layer 3 described above, can be extended from the laminated substrate 2 to the surface of the first sealing portion 8 or to the outside, where it can be connected to the external connection terminal bus bar 7.

The material of the external terminal block 4 is not particularly limited, but it is preferably the same material as the external terminal bus bar 7 described below. Metal materials such as Cu or Al, which have excellent electrical conductivity, can be used.

The bonding between the external terminal block 4 and the laminated substrate 2 is not particularly limited, but the same material as the first bonding layer 3 that bonds the power semiconductor element 1 can be used. The bonding method can also be the same as the process of bonding the power semiconductor element 1. The external terminal block 4 may also be fitted into a recess provided in the first conductive plate 23 of the laminated substrate 2.

The shape of the external terminal block 4 is preferably prismatic or cylindrical. In the case of a prismatic shape, if there are corners (corners on the side surfaces other than the joint surface), stress will be concentrated at the corners after sealing with the first sealing section 8 described below, so it is preferable that the corners are rounded (with a radius R). In this case, the radius R is not particularly limited, but it is preferable that R = 0.2 or more.

The length of the external terminal block 4 (i.e., the height from the top surface of the first conductive plate 23) is sufficient if the top surface (i.e., the connection surface) of the external terminal block 4 is exposed from the surface of the first sealing portion 8 when sealed with the first sealing portion 8. The size of the external terminal block 4 (i.e., the width of the side surface) is not particularly limited as long as it is determined according to the joining area with the external terminal bus bar 7 described below and the current rating.

The first sealing portion 8 can be formed from an epoxy resin composition that contains an epoxy resin base and a curing agent, and may optionally contain inorganic fillers and other additives. As the epoxy resin base, an aliphatic epoxy or alicyclic epoxy can be used. Alternatively, a maleimide resin or a cyanate resin can be used, and two or more types including an epoxy resin may be mixed and used. These sealing materials can adjust the linear expansion coefficient as well as provide insulation, increase the rigidity of the module (high Young's modulus), and prevent cracking.

The power semiconductor unit (hereinafter, simply referred to as the unit; shown by the dashed line in FIG. 1) sealed with the first sealing portion 8 is mounted on the base 11 via the second bonding layer 11A. The second bonding layer 11A can be bonded with solder, a sheet-shaped adhesive, or the like, without any particular problem as long as it has excellent thermal conductivity and adhesion. The material of the base 11 is not particularly limited, but materials such as AlSiC, MgSiC, and Cu can be used. The thickness is preferably in the range of 2 mm to 5 mm, depending on the material. The base 11 may be connected to a cooler (not shown). The unit may also be directly connected to the cooler via the second bonding layer 11A. By sealing with resin at the first sealing portion 8 to form a power unit semiconductor unit, the individual units can be tested for electrical characteristics, which has the advantage of not mounting defective units, but mounting the characteristics of the units together to form a semiconductor module. In addition, the unit itself can be made smaller, so thermal stress can be suppressed. Rather than increasing rigidity, the second sealing portion can be made of a material with excellent insulating properties, such as silicone resin, which can reduce thermal stress in the semiconductor module as a whole.

Furthermore, in this embodiment, the power semiconductor unit is embedded in the case 12A, which will be described later, by the second sealing portion, so there is no need to form a recessed shape on the top surface of the unit, and the shape can be made flat. A complex shape would increase the cost of the mold, but a flat shape allows the mold to be created inexpensively.

The case lid 12 may be made of a resin with excellent insulating properties, such as PPS (polyphenylene sulfide).

The external terminal bus bar 7 is a busbar of an electrical wiring member for supplying current to each electronic component and wiring, and is a conductive connection member. The external terminal bus bar 7 is, for example, a plate-shaped connection member, and is preferably held approximately parallel to the laminated substrate 20.

The external terminal busbar 7 is preferably made of the same material as the external terminal block 4, and metal materials with excellent conductivity such as Cu and Al can be used. It is particularly preferable that the external terminal block 4 and the external terminal busbar 7 are made of copper (Cu), since a Cu-Cu interface is formed.

It is also preferable to perform a treatment such as Ni plating or Ni alloy plating for the purpose of rust prevention, but in that case, it is preferable that the area to be joined to the external terminal block 4 is not plated. Although not particularly limited, the thickness of the external terminal bus bar 7 is preferably about 0.8 mm to 1.5 mm. If the base material of the external terminal bus bar 7 is Cu and is Ni or Ni alloy plated to an appropriate thickness, specifically, a plating thickness of 1 μm to 10 μm, a Cu-Cu interface is formed by ultrasonic bonding.

The configuration of the external terminal bus bar 7 and the connection between the external terminal bus bar 7 and the external terminal block 4 in this embodiment will be described in detail below. The external terminal bus bar 7 has a connection portion corresponding to the connection surface of the external terminal block 4. When multiple external terminal blocks 4 are provided, the external terminal bus bar 7 has connection portions corresponding to the multiple external terminal blocks 4.

Figure 2 is a cross-sectional view showing a schematic configuration of the external terminal busbar 7. The external terminal busbar 7 has a configuration in which a metal plate is bent into a U-shape. More specifically, the external terminal busbar 7 has a main body portion 7A and a connection portion 7B formed by bending from the main body portion 7A. Figure 3 is an enlarged cross-sectional view showing the joint between the connection portion 7B of the external terminal busbar 7 and the external terminal block 4.

More specifically, as shown in FIG. 3, the connection portion 7B is composed of a first bent portion 7B1 bent from the main body portion 7A, and a second bent portion 7B2 bent further from the first bent portion 7B1. The second bent portion 7B2 is formed so as to be parallel to the main body portion 7A. The connection portion 7B has a joining surface 7C that is joined to the connection surface 4A of the external terminal block 4. Furthermore, if the thickness of the main body portion 7A is TA and the depth of the connection portion 7B relative to the main body portion 7A (i.e., the depth of the second bent portion 7B2) is D, it is preferable that D>TA.

Ultrasonic terminal bonding (hereinafter simply referred to as ultrasonic bonding) can be used as a method for bonding the external terminal block 4 and the external terminal bus bar 7. The bonding surfaces rub against each other due to ultrasonic vibration, scattering impurities from the surface layers of the bonding surfaces, such as oxide films and adsorbed gases, and exposing clean, activated, clean metal surfaces on the bonding surfaces. Bonding can be achieved in a solid state by plastically deforming the materials using pressure. In other words, bonding can be achieved by bringing the materials close to the atomic spacing and using the bonding force between the atoms. In addition, the connection portion 7B of the external terminal bus bar 7 is easily plastically deformed, allowing for uniform bonding.

The ultrasonic bonding conditions can be set, for example, as follows: pressure between 100 N and 500 N, frequency between 19 kHz and 21 kHz, and bonding time between 300 ms and 700 ms.

The ultrasonic horn (not shown) is not particularly limited, but because the external terminal bus bar 7 is thick, a horn pattern with a wide pitch is preferable. This increases the surface pressure at the joint and makes it easier to create a joint starting point.

In the case of solder joints, the linear expansion coefficients of the solder and the external terminal bus bar 7, etc. are different, so the load due to thermal stress on the joint during thermal cycles becomes large. In the present invention, materials with the same linear expansion coefficient are used, so the load of thermal stress on the joint during thermal cycles can be reduced, improving reliability.

When the thickness of the main body portion 7A before ultrasonic bonding is TA and the thickness of the connection portion 7B (i.e., the thickness of the second bend portion 7B2) is TB, it is preferable that TA<TB and TB/3<TA<2×TB/3.

The thickness can be changed in this way by cutting or pressing. The first bent portion 7B1 may be thick on the side of the second bent portion 7B2 and thin on the side of the main body portion 7A. Specifically, the thickness of the first bent portion 7B1 on the side of the connection with the second bent portion 7B2 may be as thick as the thickness of the second bent portion, and it may become thinner as it approaches the side of the connection with the main body portion 7A, so that the thickness of the part connected to the main body portion 7A is the same as the thickness of the main body portion 7A. Having such a plate thickness has a stress relaxation effect.

Specifically, when the external terminal block 4 and the external terminal bus bar 7 are joined to form a semiconductor module and then energized for operation, the elements generate heat, generating thermal stress in each part of the module. At that time, thermal stress also acts on the external terminal bus bar 7, and tensile stress acts on the joint. Even in such a case, if the external terminal bus bar 7 is within the above range, the main body 7A can deform and the thermal stress acting on the joint can be alleviated. Furthermore, the external stress applied to the external terminal bus bar 7 during ultrasonic bonding can also be alleviated by the deformation of the main body 7A. As a result, long-term reliability in power cycle tests and the like has also been improved.

The angle (θ) between the first bent portion 7B1 and the second bent portion 7B2 is preferably 100 degrees to 150 degrees, and more preferably 105 degrees to 135 degrees. It has been found that by setting the angle in this range, the bonding strength is improved. This is thought to be because the pressure applied during ultrasonic bonding makes it easier for plastic deformation to occur. In addition, as mentioned above, long-term reliability is improved by mitigating thermal stress and external stress.

In this embodiment, a second sealing portion 9 is provided to cover the joint between the external terminal block 4 and the external terminal bus bar 7. The second sealing portion 9 may be made of any material capable of covering the joint between the external terminal block 4 and the external terminal bus bar 7, and may be made of, for example, a sealing resin or silicone gel.

In this embodiment, because the top surface of the power semiconductor unit (referring to the portion sealed with the first sealing portion 8) is flat, the joints are covered with the second sealing portion 9, making it possible to form the power semiconductor unit without having to worry about the insulation distance between the external terminal blocks 4 or between the external terminal block 4 and the conductive plate 23. In particular, in order to achieve high voltage resistance, it is necessary to increase the insulation distance, and therefore in the conventional technology the power semiconductor unit must be large, but according to this embodiment it can be made compact.

The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the scope of the following examples.

Example 1
The power semiconductor module 10 for evaluation was fabricated as follows: As the laminated substrate 2, a Denka SIN plate (manufactured by Denka, frame length 1.0 mm) having a conductive plate thickness of 0.3 mm and an insulating substrate thickness of 0.32 mm was used.

The solder 3 and power semiconductor element 1, the solder and implant pin 5, the copper (Cu) external terminal block 4 (width 3 mm x 5 mm, height 5 mm), and the printed circuit board 6 were soldered and arranged on the laminated substrate 2 in a _N2 reflow furnace. Next, these members to be sealed were set in a mold.

Next, aliphatic epoxy resin base: jER630 (Mitsubishi Chemical), hardener: jER Cure 113 (Mitsubishi Chemical), inorganic filler: Exelica (average particle size: several μm to several tens of μm) (Tokuyama) were mixed in a mass ratio of 10:5:3, then vacuum degassed and poured into a mold. This was first cured at 100°C for 1 hour, and then secondarily cured at 150°C for 3 hours, resulting in a power semiconductor unit with a flat surface and the connection part of the external terminal block exposed on the surface.

Then, the obtained power semiconductor unit was soldered to a 5 mm thick AlSiC base (manufactured by Denka) 11. The external terminal block 4 and the external terminal bus bar 7 were joined by ultrasonic bonding.

Then, the case 12A was attached to the base 11 with adhesive. Next, silicone gel (TSE3051SK, manufactured by Momentive Performance Materials Japan) was filled into the gap between the power semiconductor unit inserted into the case 12A and the case 12A, and into the upper part of the power semiconductor unit. After degassing, the gel was heated at 100°C for 1 hour to harden and seal the power semiconductor unit.

That is, the second sealing portion 9 was formed by hardening the silicone gel. The second sealing portion 9 was formed so as to embed the joint between the external terminal block 4 and the external terminal bus bar 7. Finally, the lid 12B was attached to produce the power semiconductor module 10.

Example 2
The power semiconductor module 10 was produced in the same manner as in Example 1, except that the external terminal block 4 and the external terminal bus bar 7 were joined by ultrasonic bonding and then joined to the base 11.

<Comparative Example 1>
A power semiconductor module of Comparative Example 1 was obtained in the same manner as in Example 1, except that the external terminal block 4 and the external terminal bus bar 7 were joined by soldering.

[evaluation]
A thermal cycle test was carried out on the power semiconductor modules 10 of Examples 1 and 2 and the power semiconductor module of Comparative Example 1. In the thermal cycle test, a temperature cycle of -40°C to 125°C was carried out, and the modules were removed after 500 cycles, and the degree of increase in contact resistance of the attachment portion between the external terminal block 4 and the external terminal bus bar 7 (i.e., the rate of increase when 0 cycles is used as a reference) was confirmed. The evaluation results are shown in Table 1.

熱サイクル評価では、実施例１～２のパワー半導体モジュール１０ともに、接触抵抗の上昇度合いが５％以下であり特に問題はなかった。比較例１のパワー半導体モジュールでは、１０％と接触抵抗の上昇度合いが大きかったが、これは、ブロック／バスバーの接合工程において、はんだ接合で行っているため、熱応力によって接合部が疲労したためと考えられる。
［改変例］
図４は、上記実施形態の第１の改変例であり、外部端子バスバー７の接続部７Ｂを示す断面図である。外部端子バスバー７は、本体部７Ａから屈曲して形成された第１屈曲部７Ｂ１と第２屈曲部７Ｂ２とからなるが、接続部７Ｂは、第２屈曲部７Ｂ２から屈曲し、第１屈曲部７Ｂ１よりも短い屈曲部７Ｂ３が第２屈曲部７Ｂ２の端部に形成されて終端している。従って、外部端子バスバー７の、例えば終端部７Ｅ（図２参照）に適用することによって、外部端子ブロック４と外部端子バスバー７との接合部の熱応力による疲労を低減することができ、信頼性の高い半導体モジュールを得ることができる。

In the thermal cycle evaluation, the degree of increase in contact resistance was 5% or less, which was not particularly problematic, for both the power semiconductor modules 10 of Examples 1 and 2. The degree of increase in contact resistance was large at 10% for the power semiconductor module of Comparative Example 1, but this is thought to be due to fatigue of the joint due to thermal stress caused by soldering in the joining process of the block/busbar.
[Modification example]
4 is a cross-sectional view showing a connection portion 7B of an external terminal bus bar 7, which is a first modified example of the above embodiment. The external terminal bus bar 7 is composed of a first bent portion 7B1 and a second bent portion 7B2 formed by bending from a main body portion 7A, and the connection portion 7B is bent from the second bent portion 7B2, and a bent portion 7B3 shorter than the first bent portion 7B1 is formed at an end of the second bent portion 7B2 and terminates thereat. Therefore, by applying this to, for example, the termination portion 7E (see FIG. 2) of the external terminal bus bar 7, fatigue caused by thermal stress at the joint between the external terminal block 4 and the external terminal bus bar 7 can be reduced, and a highly reliable semiconductor module can be obtained.

Figure 5 is a cross-sectional view showing the connection portion 7B of the external terminal busbar 7, which is a second modified example of the above embodiment. The external terminal busbar 7 is made up of a first bent portion 7B1 and a second bent portion 7B2 formed by bending from the main body portion 7A, and the connection portion 7B terminates at the second bent portion 7B2. Therefore, by applying this to, for example, the end portion 7E (see Figure 2) of the external terminal busbar 7, fatigue due to thermal stress at the joint between the external terminal block 4 and the external terminal busbar 7 can be reduced, and a highly reliable semiconductor module can be obtained.

According to an embodiment of the present invention, the external terminal block 4 and the external terminal bus bar 7 of the power semiconductor unit can be easily joined, and a highly reliable power semiconductor module can be provided. Note that, although the above description is directed to a power semiconductor module equipped with a power semiconductor element, the present invention can also be applied to a semiconductor module equipped with a general semiconductor element.

REFERENCE SIGNS LIST 1 Semiconductor element 2 Laminated substrate 21 Second conductive plate 22 Insulating substrate 23 First conductive plate 3 First bonding layer 4 External terminal block 5 Implant pin 6 Printed circuit board 7 External terminal bus bar 8 First sealing portion 9 Second sealing portion 10 Semiconductor module 11 Base 11A Second bonding layer 12A Case 12B Lid

Claims (7)

A laminated substrate on which a semiconductor element is mounted;
an external terminal block provided upright on a mounting surface of the laminated substrate;
an external terminal bus bar electrically connected to the external terminal block;
a first sealing portion made of a resin in which at least the laminated substrate, the semiconductor element, and the external terminal block are embedded;
the external terminal bus bar has a connection portion formed by bending a main body portion of the external terminal bus bar,
the external terminal block has a connection surface exposed from the first sealing portion,
the connection portion includes a first bent portion bent from the main body portion and a second bent portion bent further from the first bent portion and parallel to the main body portion,
The second bent portion has a joining surface that is joined to the connection surface. The semiconductor module according to claim 1, wherein the joint between the external terminal bus bar and the external terminal block is embedded in the second sealing portion. The semiconductor module according to claim 1 or 2, wherein the first sealing portion has a flat upper surface. The semiconductor module according to any one of claims 1 to 3, wherein the base material of the external terminal block and the external terminal bus bar is copper (Cu), the external terminal bus bar is plated with Ni or Ni alloy, and the joint between the external terminal bus bar and the external terminal block has a Cu-Cu interface. The semiconductor module according to any one of claims 1 to 4, wherein when the thickness of the main body of the external terminal bus bar is TA and the depth of the connection part relative to the main body is D, D>TA. Mounting a semiconductor element on a laminated substrate;
providing an external terminal block on a mounting surface of the laminated substrate;
a step of forming a first sealing portion by embedding at least the laminated substrate, the semiconductor element, and the external terminal block in a resin;
and electrically connecting an external terminal bus bar to the external terminal block.
the external terminal bus bar has a connection portion formed by bending a main body portion of the external terminal bus bar,
the connection portion includes a first bent portion bent from the main body portion and a second bent portion bent further from the first bent portion and parallel to the main body portion,
The step of forming the first sealing portion includes forming the first sealing portion such that a connection surface of the external terminal block is exposed from the first sealing portion;
A method for manufacturing a semiconductor module, wherein the connecting step includes ultrasonically bonding a bonding surface of the second bent portion to the connection surface of the external terminal block exposed from the first sealing portion. 7. The method for manufacturing a semiconductor module according to claim 6, further comprising the step of forming a second sealing portion by embedding a joint portion between the external terminal bus bar and the external terminal block, and the step of forming the first sealing portion forms the first sealing portion so that an upper surface thereof is flat.

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