Power semiconductor unit and method for manufacturing the power semiconductor unit

Abstract

To provide a power semiconductor unit including a cooler capable of balancing the cooling efficiency and mounting flexibility of the mounted power semiconductor module.SOLUTION: The power semiconductor unit includes: a power semiconductor element; a first insulating substrate bonded to one side of the power semiconductor element; a wiring metal component bonded to the other side of the power semiconductor element; a second insulating substrate bonded to the side of the wiring metal component opposite to the side to which the power semiconductor element is bonded; and a heat sink for cooling the heat from the power semiconductor element. The connection between the power semiconductor element and the first insulating circuit board, the connection between the power semiconductor element and the wiring metal component, and the connection between the wiring metal component and the second insulating substrate are a sintered metal joint.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a structure of a power semiconductor unit and a manufacturing method thereof, and more particularly to a technique that is effective when applied to a power semiconductor unit equipped with a cooler. [Background technology]

[0002] In recent years, environmentally friendly vehicles such as hybrid electric vehicles (HVs) and electric vehicles (EVs) have become more common as environmental awareness increases. To further popularize next-generation HVs and EVs, development of smaller, lower-cost, and more efficient electric systems is underway, and one of the important issues in this regard is the miniaturization, lower cost, and higher efficiency of power semiconductor units.

[0003] Background art relating to in-vehicle power semiconductor units includes, for example, technology such as that described in Patent Document 1. Patent Document 1 discloses the configuration of a power semiconductor module in which insulating substrates attached to both sides of a power semiconductor element and cooling means such as a heat sink are joined by brazing, such as soldering or brazing.

[0004] The configuration of Patent Document 1 significantly reduces the thermal resistance between the power semiconductor element and the cooling means, making it possible to obtain high cooling performance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-124430 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above Patent Document 1, the power semiconductor elements 1, 2 are joined to the insulating substrates 9, 18 by soldering or the like, and the insulating substrates 9, 18 are further joined to the heat sinks 13, 23 provided with heat dissipation fins by brazing (soldering or brazing).

[0007] Therefore, due to the heat generated during the soldering process when joining the heat sinks 13, 23 to the insulating substrates 9, 18, the solder at the joints between the power semiconductor elements 1, 2 and the insulating substrates 9, 18 may re-melt, raising concerns about a decrease in the reliability and heat transfer (cooling efficiency) of the joints between the power semiconductor elements 1, 2 and the insulating substrates 9, 18.

[0008] Patent Document 1 discloses that a high-temperature bonding material, for example a mixture of copper particles and tin particles, is used as a bonding material, such as solder, for bonding the power semiconductor elements 1, 2 to the insulating substrates 9, 18, and that a bonding material, such as solder, for bonding the heat sinks 13, 23 to the insulating substrates 9, 18 has a lower melting point than the bonding material, such as solder, for bonding the power semiconductor elements 1, 2 to the insulating substrates 9, 18, for example Sn-3Ag-0.5Cu lead-free solder.

[0009] However, both the CuSn solder, which is a high-temperature joining material exemplified in Patent Document 1, and the Sn-3Ag-0.5Cu lead-free solder are solders, and even the CuSn solder, which is a high-temperature joining material, contains Sn and has a melting point of at most 350°C. Therefore, there is a limit to how much the melting point can be changed, and the heat generated when making the Sn-3Ag-0.5Cu lead-free solder may deteriorate the quality of the CuSn solder.

[0010] Furthermore, when attempting to configure an in-vehicle electric system using the power semiconductor module of Patent Document 1, it is necessary to design a mounting structure that takes into account remelting of the solder at the joints between the power semiconductor elements 1, 2 and the insulating substrates 9, 18, which imposes certain constraints on mounting the power semiconductor module.

[0011] Therefore, an object of the present invention is to provide a power semiconductor unit equipped with a cooler, which is capable of achieving both cooling efficiency and mounting freedom for a mounted power semiconductor module, and a manufacturing method thereof. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention Power semiconductor units teeth, A power semiconductor module according to an embodiment of the present invention includes: a plurality of power semiconductor modules; and a heat sink for cooling the plurality of power semiconductor modules, a power semiconductor element, a first insulating substrate bonded to one surface of the power semiconductor element, a wiring metal component bonded to the other surface of the power semiconductor element, and a second insulating substrate bonded to a surface of the wiring metal component opposite to the surface to which the power semiconductor element is bonded; the heat sink has a first heat sink joined to a surface of the first insulating substrate opposite to a surface to which the power semiconductor element is joined, and a second heat sink joined to a surface of the second insulating substrate opposite to a surface to which the wiring metal component is joined, the first insulating substrate and the heat sink and the second insulating substrate and the second heat sink are joined by solder bonding or sintered metal bonding, the plurality of power semiconductor modules are arranged in parallel in a planar direction between the first heat sink and the second heat sink, The bonding between the power semiconductor element and the first insulating substrate, the bonding between the power semiconductor element and the metal wiring component, and the bonding between the metal wiring component and the second insulating substrate are characterized by being sintered metal bonding.

[0013] In addition, the present invention Manufacturing method for power semiconductor unit is as mentioned above. A method for manufacturing a power semiconductor unit, comprising: (a) By sintered metal bonding, The above On the first insulating substrate The above (b) bonding a power semiconductor element to the power semiconductor element by sintered metal bonding; The above (c) bonding a metal wiring component to the metal wiring component by sintering metal bonding. The above (d) a step of sealing the first insulating substrate, the power semiconductor element, the wiring metal component, and the second insulating substrate with a sealing resin; (e) after the step (d), sealing the first insulating substrate by solder bonding or sintered metal bonding. The above and bonding the power semiconductor unit to a heat sink. Effect of the Invention

[0015] According to the present invention, it is possible to realize a power semiconductor unit including a cooler, which is capable of achieving both cooling efficiency and freedom of mounting of a mounted power semiconductor module, and a method for manufacturing the same.

[0016] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0017] [Figure 1]1 is a diagram showing a cross-sectional structure of a power semiconductor unit according to a first embodiment of the present invention. [Figure 2A] FIG. 11 is a diagram showing a configuration of a power semiconductor unit according to a second embodiment of the present invention. [Figure 2B] 2B is a diagram showing a method of incorporating the power semiconductor unit of FIG. 2A into a cooling jacket. [Diagram 3] FIG. 2C is a diagram showing a modification of FIGS. 2A and 2B. [Figure 4] FIG. 11 is a diagram showing an example of mounting a power semiconductor unit according to a second embodiment of the present invention. [Figure 5A] FIG. 11 is a diagram showing a configuration of a power semiconductor unit according to a third embodiment of the present invention. [Figure 5B] FIG. 5B is a diagram showing a cross section taken along the line AA' of FIG. 5A. [Figure 6A] FIG. 11 is a diagram showing a configuration of a power semiconductor unit according to a fourth embodiment of the present invention. [Figure 6B] FIG. 6B is a diagram showing a cross section taken along the line BB' of FIG. 6A. [Figure 7A] FIG. 11 is a diagram showing a configuration of a power semiconductor unit according to a fifth embodiment of the present invention. [Figure 7B] FIG. 7B is a view showing a CC' cross section of FIG. 7A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and detailed description of overlapping parts will be omitted. EXAMPLES

[0019] A power semiconductor unit according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing a cross-sectional structure of a power semiconductor unit 1 according to the present embodiment.

[0020] In this specification, a semiconductor chip on which a power semiconductor element such as a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an insulated gate bipolar transistor (IGBT), or a diode is formed is referred to as a "power semiconductor element", a power semiconductor element mounted on an insulating substrate and sealed with resin is referred to as a "power semiconductor module", and a power semiconductor module equipped with a cooler such as a heat sink is referred to as a "power semiconductor unit".

[0021] As shown in FIG. 1, the power semiconductor unit 1 of the present embodiment mainly comprises a power semiconductor element 3 which is a semiconductor chip on which a power semiconductor element such as an IGBT is formed, an insulating substrate 2 bonded to the underside of the power semiconductor element 3, a wiring metal part 4 such as a spacer or a lead frame bonded to the upper side of the power semiconductor element 3, an insulating substrate 5 bonded to the surface of the wiring metal part 4 opposite to the surface to which the power semiconductor element 3 is bonded, and heat sinks 6 and 7 for cooling heat from the power semiconductor element 3.

[0022] The insulating substrate 2 is, for example, a DBC substrate (Direct Bonded Copper) in which copper plates 9, 10 are bonded to both sides of a ceramic substrate 8. Similarly, the insulating substrate 5 is, for example, a DBC substrate in which copper plates 12, 13 are bonded to both sides of a ceramic substrate 11.

[0023] The heat sinks 6 and 7 are provided with cooling fins, and cool the heat from the power semiconductor elements 3 by heat exchange with a coolant 19. In the case of an air-cooled heat sink, the coolant 19 is a gas such as air, and in the case of a liquid-cooled heat sink, the coolant 19 is cooling water, LLC (Long Life Coolant), or the like.

[0024] A sintered metal 14 is interposed between the power semiconductor element 3 and the insulating substrate 2, and the power semiconductor element 3 and the insulating substrate 2 are sintered-metal bonded by the sintered metal 14.

[0025] Furthermore, a sintered metal 15 is interposed between the power semiconductor element 3 and the wiring metal component 4 , and the power semiconductor element 3 and the wiring metal component 4 are sintered-metal bonded by the sintered metal 15 .

[0026] Furthermore, a sintered metal 16 is interposed between the wiring metal component 4 and the insulating substrate 5 , and the wiring metal component 4 and the insulating substrate 5 are sintered-metal bonded by the sintered metal 16 .

[0027] Sintered silver, sintered copper, etc. are used for the sintered metals 14, 15, 16. The melting point of sintered metals such as sintered silver and sintered copper is high, at 900°C or higher. The sintering temperature of the sintered metal joints that form the sintered metals 14, 15, 16 is about 200°C to 350°C, and the sintered metal joints are characterized in that once joined, the melting point becomes much higher than the sintering temperature.

[0028] The heat sink 6 is bonded to the surface of the insulating substrate 2 opposite to the surface to which the power semiconductor element 3 is bonded, and solder or sintered metal 17 is interposed at the joint between the insulating substrate 2 and the heat sink 6, and the insulating substrate 2 and the heat sink 6 are metal-bonded by the solder or sintered metal 17. In this way, since the structure is a so-called direct cooling structure in which the thermal connection is made by a metal bonding material, rather than a so-called indirect cooling structure in which the thermal connection is made by a thermal grease or a thermal sheet, the thermal resistance of the connection can be reduced. In addition, the melting point of the solder is about 200°C to 350°C. Similarly, a sintering temperature of about 200°C to 350°C can be applied for the sintering metal bonding to form the sintered metal 17. Therefore, the process of bonding by the solder or sintered metal 17 is performed at a temperature much lower than the melting point of the sintered metals 14, 15, and 16 formed in the previous process, and therefore problems such as remelting of the sintered metals 14, 15, and 16 and deterioration of quality do not occur.

[0029] In addition, the heat sink 7 is joined to the surface of the insulating substrate 5 opposite to the surface to which the wiring metal component 4 is joined, and solder or sintered metal 18 is interposed at the joint between the insulating substrate 5 and the heat sink 7, and the insulating substrate 5 and the heat sink 7 are metal-joined by the solder or sintered metal 18.

[0030] Only the main steps of the method for manufacturing the power semiconductor unit 1 will be described with reference to FIG.

[0031] First, the power semiconductor element 3 is bonded onto the insulating substrate 2 by sintered metal bonding. At this time, a sintered metal 14 is formed between the insulating substrate 2 and the power semiconductor element 3 as a bonding layer.

[0032] Next, the wiring metal component 4 is bonded onto the power semiconductor element 3 by sintered metal bonding. At this time, a sintered metal 15 is formed between the power semiconductor element 3 and the wiring metal component 4 as a bonding layer.

[0033] Subsequently, the insulating substrate 5 is bonded onto the wiring metal component 4 by sintered metal bonding. At this time, a sintered metal 16 is formed between the wiring metal component 4 and the insulating substrate 5 as a bonding layer.

[0034] The order of joining is not limited to the above order. Also, by using a positioning jig to fix the position of each part, it is possible to perform two or all of the joining processes of sintered metal 14, sintered metal 15, and sintered metal 16 at once.

[0035] Next, the insulating substrate 2, the power semiconductor element 3, the wiring metal component 4, and the insulating substrate 5 are sealed with a sealing resin (not shown). In Fig. 1, the sealing resin is not shown to make the structure easier to understand, but for example, a high heat resistant resin sealing is performed by transfer molding or the like to form a power semiconductor module.

[0036] After the resin sealing, the insulating substrate 2 and the heat sink 6, and the insulating substrate 5 and the heat sink 7 are respectively joined by soldering or sintered metal joining.

[0037] The power semiconductor unit 1 of the present embodiment is configured as described above, and sintered metals 14, 15, and 16 having a melting point of 900°C or higher are used to join the power semiconductor element 3 to the insulating substrate 2, the power semiconductor element 3 to the wiring metal component 4, and the wiring metal component 4 to the insulating substrate 5, respectively. Therefore, when joining the insulating substrate 2 to the heat sink 6, and the insulating substrate 5 to the heat sink 7 using solder or sintered metals 17, 18 having a melting point or sintering temperature of approximately 200°C to 350°C, respectively, there is no need to consider remelting or deterioration in quality of the sintered metals 14, 15, and 16 inside the power semiconductor module.

[0038] This improves the degree of freedom in mounting the heat sinks 6 and 7 to the power semiconductor module, and ensures the reliability of the joints inside the power semiconductor module and between the power semiconductor module and the heat sink. In addition, the thermal resistance of the connection between the heat sinks 6 and 7 and the power semiconductor module can be reduced, improving the cooling efficiency of the entire power semiconductor unit. EXAMPLES

[0039] A power semiconductor unit according to a second embodiment of the present invention will be described with reference to Fig. 2A to Fig. 4. Fig. 2A is a diagram showing the configuration of a power semiconductor unit 1 according to this embodiment. Fig. 2B is a diagram showing a method of incorporating the power semiconductor unit 1 of Fig. 2A into a cooling jacket 21. Fig. 3 is a diagram showing a modified example of Figs. 2A and 2B. Fig. 4 is a diagram showing an example of mounting the power semiconductor unit 1 according to this embodiment.

[0040] As described in the first embodiment, the power semiconductor unit 1 is formed by bonding the heat sinks 6 and 7 to both sides of the power semiconductor module 20 by metal bonding such as solder bonding or sintered metal bonding, as shown in FIG. 2A.

[0041] The power semiconductor unit 1 configured as shown in FIG. 2A is incorporated into a cooling jacket 21 having a plurality of openings 23 as shown in FIG. 2B, for example, and is cooled by heat exchange with a refrigerant such as water or LLC flowing through a water passage 22.

[0042] When the power semiconductor unit 1 is assembled into the cooling jacket 21, the power semiconductor unit 1 is joined to the inside of the opening 23 of the cooling jacket 21 by solder joining or sintered metal joining.

[0043] 3, it is also possible to configure a power semiconductor unit by directly bonding the power semiconductor module 20, to which the heat sinks 6 and 7 are not bonded, to a cooling jacket 24 incorporating cooling fins by solder bonding or sintered metal bonding. In this case, the cooling jacket 24 serves as a liquid-cooled heat sink. In the flow path of the cooling jacket 24, pin fins or the like (not shown) are provided to improve the cooling efficiency.

[0044] In addition, since the power semiconductor unit 1 configured as shown in FIG. 2A has improved cooling efficiency and mounting flexibility, it can be mounted together with a capacitor 25 or the like as shown in FIG. 4 and used as a power semiconductor unit for electric vehicles (EVs) that require high reliability.

[0045] An example of the configuration of the power semiconductor unit in FIG. 4 will be described later in Example 4 (FIGS. 6A and 6B). EXAMPLES

[0046] A power semiconductor unit according to a third embodiment of the present invention will be described with reference to Figures 5A and 5B. Figure 5A is a diagram showing the configuration of the power semiconductor unit according to the third embodiment. Figure 5B is a diagram showing a cross section taken along line AA' of Figure 5A.

[0047] 5A and 5B, the power semiconductor unit of this embodiment has a heat sink configured with two aluminum fixing bars 26 and a cooling jacket 24 disposed between the two aluminum fixing bars 26. The cooling jacket 24 also functions as a liquid-cooled heat sink. The aluminum fixing bar 26 also functions as an air-cooled heat sink.

[0048] Between the lower aluminum fixing bar 26 and the cooling jacket 24, there is a first power semiconductor module group in which a plurality of power semiconductor modules 20 are arranged in parallel.

[0049] Between the upper aluminum fixing bar 26 and the cooling jacket 24, there is a second power semiconductor module group in which a plurality of power semiconductor modules 20 are arranged in parallel.

[0050] The lower aluminum fixing bar 26 and the power semiconductor module 20, the cooling jacket 24 and the power semiconductor module 20, and the upper aluminum fixing bar 26 and the power semiconductor module 20 are joined by solder joints or sintered metal joints.

[0051] Two pairs of mirror-symmetric terminal arrangements are used for the power semiconductor module 20. Each of the upper-layer power semiconductor module 20 and the lower-layer power semiconductor module 20 has a main terminal through which a main current flows and a control terminal including at least a gate terminal, and the control terminal of the upper-layer power semiconductor module 20 is bent and extends in the opposite direction to the control terminal of the lower-layer power semiconductor module 20.

[0052] In the power semiconductor unit of this embodiment, as described above, the heat sink has at least one liquid-cooled heat sink (cooling jacket 24), and only one of the two main surfaces of the upper power semiconductor module 20 is thermally connected to the cooling jacket 24, while only one of the two main surfaces of the lower power semiconductor module 20 is thermally connected to the cooling jacket 24. This makes it possible to reduce the number of liquid-cooled heat sinks.

[0053] Moreover, one main surface of the upper power semiconductor module 20 is joined to the cooling jacket 24 via a metal bonding material such as solder bonding or sintered metal bonding, and one main surface of the lower power semiconductor module 20 is joined to the cooling jacket 24 via a metal bonding material such as solder bonding or sintered metal bonding. In this way, since a so-called direct cooling structure is used in which the modules are thermally connected by a metal bonding material, rather than a so-called indirect cooling structure in which the modules are thermally connected by a heat dissipation grease or a heat dissipation sheet, the thermal resistance of the connection portion can be reduced.

[0054] Although the thermal resistance of the connection portion is higher than that of a metal joint material, it is also possible to use heat dissipation grease or a heat dissipation sheet instead of a metal joint material such as solder joint or sintered metal joint.

[0055] By configuring the power semiconductor unit as in this embodiment (FIGS. 5A and 5B), it is possible to achieve a configuration that emphasizes small size and light weight and has good cost performance. EXAMPLES

[0056] A power semiconductor unit according to a fourth embodiment of the present invention will be described with reference to Fig. 6A and Fig. 6B. Fig. 6A is a diagram showing the configuration of the power semiconductor unit according to the fourth embodiment. Fig. 6B is a diagram showing a cross section taken along line BB' in Fig. 6A.

[0057] As shown in FIGS. 6A and 6B, in the power semiconductor unit of this embodiment, the heat sink is configured with two cooling jackets 24 arranged above and below each other.

[0058] A plurality of power semiconductor modules 20 are stacked in two layers between two cooling jackets 24, and the upper layer power semiconductor module 20 and the lower layer power semiconductor module 20 are joined to each other by solder joints or sintered metal joints.

[0059] In addition, the lower cooling jacket 24 is joined to the surface of the insulating substrate 2 of the lower power semiconductor module 20 opposite to the surface to which the power semiconductor elements 3 are joined, and the upper cooling jacket 24 is joined to the surface of the insulating substrate 5 of the upper power semiconductor module 20 opposite to the surface to which the wiring metal components 4 are joined.

[0060] The insulating substrate 2 of the lower power semiconductor module 20 is joined to the lower cooling jacket 24, and the insulating substrate 5 of the upper power semiconductor module 20 is joined to the upper cooling jacket 24 by solder bonding or sintered metal bonding.

[0061] Between the upper cooling jacket 24 and the lower cooling jacket 24, a plurality of power semiconductor modules 20 are arranged in parallel and are also arranged one above the other.

[0062] In the power semiconductor unit of this embodiment, as described above, the heat sink has two cooling jackets 24 arranged one above the other, with the upper cooling jacket 24 thermally connected to one main surface of the upper power semiconductor module 20 and the lower cooling jacket 24 thermally connected to one main surface of the lower power semiconductor module 20, and the other main surface of the upper power semiconductor module 20 and the other main surface of the lower power semiconductor module 20 are thermally connected.

[0063] Although the thermal resistance of the connection portion is higher than that of a metal joint material, it is also possible to use heat dissipation grease or a heat dissipation sheet instead of a metal joint material such as solder joint or sintered metal joint.

[0064] By configuring the power semiconductor unit as in this embodiment (FIGS. 6A and 6B), it is possible to achieve a configuration that emphasizes small size and light weight and has good cost performance. EXAMPLES

[0065] A power semiconductor unit according to a fifth embodiment of the present invention will be described with reference to Fig. 7A and Fig. 7B. Fig. 7A is a diagram showing the configuration of the power semiconductor unit according to the fifth embodiment. Fig. 7B is a diagram showing a CC' cross section of Fig. 7A.

[0066] As shown in FIGS. 7A and 7B, in the power semiconductor unit of this embodiment, the heat sink is configured with three cooling jackets 24 arranged in three layers, one above the other.

[0067] A plurality of power semiconductor modules 20 are stacked in two layers between three cooling jackets 24, and the upper layer power semiconductor module 20 is joined between the topmost cooling jacket 24 and the middle cooling jacket 24 by solder bonding or sintered metal bonding.

[0068] Moreover, the lower layer power semiconductor module 20 is joined between the lowermost cooling jacket 24 and the middle cooling jacket 24 by solder joints or sintered metal joints.

[0069] Although the thermal resistance of the connection portion is higher than that of a metal joint material, it is also possible to use heat dissipation grease or a heat dissipation sheet instead of a metal joint material such as solder joint or sintered metal joint.

[0070] By configuring the power semiconductor unit as in this embodiment (FIGS. 7A and 7B), both sides of all the power semiconductor modules 20 are cooled by the liquid-cooled cooling jackets 24, which is advantageous when prioritizing maximum output of the power semiconductor unit.

[0071] The present invention is not limited to the above-described embodiments, and includes various modified examples. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0072] 1...Power semiconductor unit 2,5…Insulating substrate 3...Power semiconductor element 4... Metal wiring parts 6,7…Heat sink 8,11…Ceramic substrate 9,10,12,13…Copper plate 14, 15, 16...Sintered metal 17,18...Solder or sintered metal 19...Refrigerant 20...Power semiconductor module 21,24…Cooling jacket 22...Waterway 23…Opening 25…Capacitor 26…Aluminum fixing bar

Claims

1. A plurality of power semiconductor modules; a heat sink for cooling the plurality of power semiconductor modules; Each of the plurality of power semiconductor modules includes a power semiconductor element, a first insulating substrate bonded to one surface of the power semiconductor element, a wiring metal component bonded to the other surface of the power semiconductor element, and a second insulating substrate bonded to a surface of the wiring metal component opposite to the surface to which the power semiconductor element is bonded, the heat sink includes a first heat sink bonded to a surface of the first insulating substrate opposite to a surface to which the power semiconductor element is bonded, and a second heat sink bonded to a surface of the second insulating substrate opposite to a surface to which the wiring metal component is bonded, the first insulating substrate and the heat sink, and the second insulating substrate and the second heat sink are joined by solder bonding or sintered metal bonding; the plurality of power semiconductor modules are arranged in parallel between the first heat sink and the second heat sink in a planar direction, A power semiconductor unit, characterized in that the bonding between the power semiconductor element and the first insulating substrate, the bonding between the power semiconductor element and the wiring metal component, and the bonding between the wiring metal component and the second insulating substrate are sintered metal bonding.

2. 2. The power semiconductor unit according to claim 1, The power semiconductor unit, wherein the sintered metal joint is a sintered silver joint or a sintered copper joint.

3. 2. The power semiconductor unit according to claim 1, the heat sink is bonded to a surface of the first insulating substrate opposite to a surface to which the power semiconductor element is bonded, The power semiconductor unit according to claim 1, wherein the first insulating substrate and the heat sink are joined by soldering or sintered metal joining.

4. 2. The power semiconductor unit according to claim 1, The power semiconductor unit is characterized in that the heat sink cools heat from the power semiconductor element by heat exchange with a gas or liquid.

5. 2. The power semiconductor unit according to claim 1, A power semiconductor unit, characterized in that the power semiconductor element, the first insulating substrate, the wiring metal component, and the second insulating substrate are sealed with the same sealing resin.

6. 2. The power semiconductor unit according to claim 1, the plurality of power semiconductor modules are stacked in two layers between the first heat sink and the second heat sink, A power semiconductor unit, characterized in that an upper layer power semiconductor module and a lower layer power semiconductor module are joined by solder joints or sintered metal joints.

7. 2. The power semiconductor unit according to claim 1, The heat sink includes a third heat sink, the plurality of power semiconductor modules include a first power semiconductor module group in which the plurality of power semiconductor modules are arranged in parallel in a planar direction between the first heat sink and the second heat sink, the plurality of power semiconductor modules include a second power semiconductor module group in which the plurality of power semiconductor modules are arranged in parallel in a planar direction between the second heat sink and the third heat sink, a bonding between the first heat sink and the power semiconductor module, a bonding between the second heat sink and the power semiconductor module, and a bonding between the third heat sink and the power semiconductor module, the bonding being a solder bonding or a sintered metal bonding.

8. 8. The power semiconductor unit according to claim 7, the second heat sink is disposed between the first heat sink and the third heat sink; the second heat sink is a liquid-cooled heat sink, The power semiconductor unit, wherein the first heat sink and the third heat sink are air-cooled heat sinks.

9. A method for manufacturing a power semiconductor unit according to claim 1, comprising the steps of: (a) bonding the power semiconductor element onto the first insulating substrate by sintered metal bonding; (b) joining the wiring metal component onto the power semiconductor element by sintered metal joining; (c) bonding the second insulating substrate onto the wiring metal component by sintered metal bonding; (d) sealing the first insulating substrate, the power semiconductor element, the wiring metal component, and the second insulating substrate with a sealing resin; (e) after (d), joining the first insulating substrate to the heat sink by solder bonding or sintered metal bonding.

10. In the power semiconductor unit according to claim 1, the plurality of power semiconductor modules include a first power semiconductor module and a second power semiconductor module overlapping the first power semiconductor module, The heat sink comprises at least one liquid-cooled heat sink; the first power semiconductor module has two main surfaces, only one of which is thermally connected to the liquid-cooled heat sink; The second power semiconductor module is a power semiconductor unit, characterized in that only one of two main surfaces of the second power semiconductor module is thermally connected to the liquid-cooled heat sink.

11. 11. The power semiconductor unit according to claim 10, the first power semiconductor module has one main surface joined to the liquid-cooled heat sink via a metal joining material; The second power semiconductor module has one of the main surfaces joined to the liquid-cooled heat sink via a metal joining material.

12. 11. The power semiconductor unit according to claim 10, the first power semiconductor module has one main surface thermally connected to the liquid-cooled heat sink via a thermal dissipation grease or a thermal dissipation sheet; The second power semiconductor module is a power semiconductor unit characterized in that the one main surface of the second power semiconductor module is thermally connected to the liquid-cooled heat sink via a heat dissipation grease or a heat dissipation sheet.

13. 11. The power semiconductor unit according to claim 10, the heat sink comprises a first heat sink that is not liquid-cooled and a second heat sink that is not liquid-cooled; the one main surface of the first power semiconductor module and the one main surface of the second power semiconductor module are thermally connected to a common liquid-cooled heat sink; the first heat sink is thermally connected to the other main surface of the first power semiconductor module; The power semiconductor unit, wherein the second heat sink is thermally connected to the other main surface of the second power semiconductor module.

14. 11. The power semiconductor unit according to claim 10, The heat sink includes a first liquid-cooled heat sink and a second liquid-cooled heat sink, the first liquid-cooled heat sink is thermally connected to the one main surface of the first power semiconductor module; the second liquid-cooled heat sink is thermally connected to the one main surface of the second power semiconductor module; a second main surface of the first power semiconductor module and a second main surface of the second power semiconductor module being thermally connected to each other;

15. 11. The power semiconductor unit according to claim 10, Each of the first power semiconductor module and the second power semiconductor module has a main terminal through which a main current flows and a control terminal including at least a gate terminal, A power semiconductor unit, characterized in that the control terminal of the first power semiconductor module is bent and extends in a direction opposite to the control terminal of the second power semiconductor module.

Images