Method for attaching terminals to a metal substrate structure for a semiconductor power module and semiconductor power module

Abstract

A method for attaching a terminal (4) to a metal substrate structure (3) for a semiconductor power module (10) includes providing at least one terminal (4) and providing a metal substrate structure (3) having a metal top layer (17), a metal bottom layer (19), and an insulating resin layer (18) disposed between the metal top layer (17) and the metal bottom layer (19). The method further includes providing at least one blind hole (7) that penetrates the metal bottom layer (19) and the insulating layer (18), with at least one terminal (4) positioned on the metal top layer (17) on the side opposite the blind hole (7) and at least one terminal (4) being coupled to the metal top layer (17) by welding.

Description

Technical Field

[0001] The present disclosure relates to a method for attaching terminals to a metal substrate structure for a semiconductor power module having an insulating layer. The present disclosure further relates to a semiconductor power module for a semiconductor device.

Background Art

[0002] European Patent Application Publication No. 0645815 describes a high-power module containing a high-power high-frequency semiconductor switching device and its operating method. The high-power module incorporates compositional, geometric, and electrical symmetries. The high-power module also includes short internal leads, a special IC chip substrate, a trimable gate lead resistor, a special composite metal / ceramic baseplate, and a special terminal conductor overlap.

[0003] Conventional insulated metal substrates implement technologies for low and medium power semiconductor modules having low insulation requirements and low heat resistance requirements simultaneously. Terminals are attached to the insulated metal substrate, and a reliable connection of the terminals on the insulated metal substrate is required. When the reliability requirements are low, the terminals can be soldered or adhered onto the substrate. The welding process can be important for the substrate structure. Considering the conventional configuration of such an insulated metal substrate, the corresponding terminals are connected to the top metallization using welding technology to provide a bonded connection. This can be important for a stable process on a substrate having a resin insulation sheet under the metallization. The welding process can lead to damage to the substrate structure. For example, ultrasonic welding imparts a strong impact of thermal, mechanical, and thermo-mechanical stresses to the substrate structure due to the friction and pressure between the terminal legs and the substrate. Here, the resin sheet is strongly at risk of deformation and crack formation. Further, there is a risk that the metallization peels off from the resin sheet layer. Applying ultrasonic welding of terminal legs to the circuit metallization of an insulated metal substrate can result in corresponding failure modes.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object is to avoid a failure mode due to a welding terminal leg in metallization.

Means for Solving the Problems

[0005] This object is solved by the features of the independent claims. Therefore, a method for attaching a terminal to a metal substrate structure is provided, which can contribute to a low-cost metal substrate structure for a semiconductor power module that enables highly reliable operation even in high-voltage power module applications with high reliability requirements. Furthermore, a corresponding semiconductor power module is provided.

[0006] Therefore, a method for attaching a terminal to a metal substrate structure for a semiconductor power module includes providing at least one terminal having a terminal body and a terminal leg, and providing a metal substrate structure having a metal top layer, a metal bottom layer, and an insulating layer disposed between the metal top layer and the metal bottom layer. The method further includes providing at least one stop hole that penetrates the metal bottom layer and the insulating layer such that at least one self-standing portion of the metal top layer is available. The method further includes coupling at least one terminal to at least one self-standing portion of the metal top layer of the metal substrate structure by welding, whereby a failure mode due to welding of the terminal leg in metallization is avoided.

[0007] The terminal can implement a main terminal and / or an auxiliary terminal made of copper or a copper alloy, and is welded to the circuit metallization of the insulated metal substrate by, for example, ultrasonic welding and / or laser welding or other applicable welding methods. Depending on the type and material of the terminal, the terminal leg can have a thickness of 0.25 to 2.0 mm. The top surface of the substrate and / or the terminal leg may be coated with a metal layer made of, for example, nickel, silver, and / or gold, for example, to improve the welding process or for protection from oxidation.

[0008] As welding means, ultrasonic welding by an ultrasonic welding head or laser welding by a laser beam is preferably used. The above-mentioned welding head is also known as a sonotrode.

[0009] The stop holes in the metal bottom layer and the insulating resin layer are intentionally formed cavities. The stop holes make it possible to protect the insulating layer from mechanical and thermal shocks introduced by ultrasonic welding and / or laser welding, and to realize a self-standing portion of the circuit metallization of the top metal layer under the terminals. The stop holes provide a space such that the propagation of mechanical and thermal stresses to the insulating layer is reduced.

[0010] The position on the insulating metal substrate where the terminals are mounted is usually not very important for heat dissipation. In positions important for thermal problems, such as directly under a chip that generates strong heat dissipation, stop holes are not available.

[0011] During the welding process, opposing elements may be applied to the open back side of the self-standing portion of the circuit metallization to provide mechanical support. The use of opposing elements may be particularly required in welding processes where the metal substrate is exposed to strong mechanical shocks such as pressure and vibration typically occurring in ultrasonic welding. The opposing elements may also provide improved heat dissipation that reduces the lateral heat flow in the circuit metallization and the surrounding substrate structure. Furthermore, the use of at least temporary protection of the chip or other module structures against particles generated by the welding process may be considered. The corresponding protection may be realized, for example, by coating the visible structure with a resin material.

[0012] After the welding process, the stop holes can be filled with an epoxy resin or other electrically insulating material. The material used for filling may contain any filling material such as particles or fibers in order to improve the mechanical and thermal performance. The filling process may be performed, for example, by dispensing or injection.

[0013] By the method described, it is possible to achieve a bonded connection by ultrasonic welding and / or laser welding on an insulated metal substrate, which can contribute to the stable and highly reliable operation of semiconductor power modules even in high-voltage power module applications. This method contributes, for example, to securely attaching terminals on an insulated metal substrate by ultrasonic welding and / or laser welding and / or any other applicable welding method that reduces the risk of damage to the insulating layer.

[0014] Considering alternative connection processes, ultrasonic welding and / or laser welding offer improved reliability of the ultrasonic welding interface and / or laser welding interface against thermal load cycles, improved heat conduction from the interface, ease of manufacturing, and throughput compared to soldering or adhesive bonded connections. It is also possible to use ultrasonic welding and / or laser welding as established techniques for insulated metal substrate structures with through-holes that penetrate the metal bottom layer and the insulating layer. There is no need to redesign the housing or the terminals.

[0015] By using the method described for manufacturing a metal substrate structure with one or more terminals attached, it is possible to counteract the aforementioned adverse effects by through-holes clearly introduced through the metal bottom layer and the insulating layer. One or more through-holes in the metal substrate structure attenuate or reduce the mechanical and thermal shock of welding the terminals onto the insulated metal substrate structure, which can cause severe damage to the underlying insulating layer in the vicinity of the welded connection. The risk of crack or damage formation in the insulating layer and delamination of the metal top layer can be reduced. Generally, the through-holes provide a space such that the propagation of thermal, mechanical, and thermo-mechanical stresses on the substrate structure, particularly into the insulating layer, is reduced.

[0016] For example, a stable semiconductor power module that enables highly reliable operation is achievable even for high-voltage power module applications in a voltage range from 0.5 kV up to a maximum of 10.0 kV. However, the described method also enables the manufacture of metal substrate structures and semiconductor power modules that can be applied to a variety of miscellaneous products, such as low-voltage industrial and automotive products operating in a voltage range of 0.5 kV or less. One or more terminals can be welded directly to the surface of the top metal layer, for example, to form a direct contact between copper and copper.

[0017] Finally, it is pointed out that all of the proposed features and methods can be used alone, but combinations of two or more can also be used.

[0018] The present disclosure relates to the welding of power and auxiliary terminals on a substrate structure based on alternative metal substrate structure technologies, such as stamped and formed metal substrate structures, not only on an insulated metal substrate or insulated metal baseplate. For example, the insulated metal substrate includes a relatively thick metal base or bottom layer made of, for example, aluminum and / or copper and / or corresponding alloys. The insulated metal substrate further comprises an insulating sheet based on a resin material forming a resin layer and a circuit metallization made of aluminum and / or copper and / or corresponding alloys forming a top metal layer. The resin material used for the insulating sheet is typically a thermosetting resin containing a thermally conductive filler material, or a thermoplastic resin.

[0019] As a result of being able to manufacture the described metal substrate structure by the described embodiments of the method, and as a result of the described semiconductor power module including an embodiment of the metal substrate structure, the described features and characteristics of the method are also disclosed with respect to the metal substrate structure and the semiconductor power module, and vice versa. Accordingly, the present disclosure includes several aspects, and all features described with respect to one aspect are disclosed herein with respect to other aspects as well, even if each feature is not explicitly recited in the context of a particular aspect.

[0020] Exemplary embodiments are described below using schematic diagrams and reference numbers.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0022] The accompanying drawings are included to provide further understanding. It should be understood that the embodiments shown in the drawings are exemplary representations and are not necessarily drawn to scale. The same reference numbers indicate elements or components having the same function. The description of each of the following figures will not be repeated as long as the elements or components correspond to each other with respect to their functions in different figures. For clarity, elements may not be labeled with corresponding reference signs in all figures in some cases.

[0023] FIG. 35 shows a side view of a terminal 4 attached to a metal substrate structure 3 of a semiconductor power module 10 for a semiconductor device. The semiconductor power module 10 includes a metal substrate structure 3 having a metal top layer 17, a metal bottom layer 19, and an insulating layer 18. The insulating layer 18 is disposed between the metal top layer 17 and the metal bottom layer 19 with respect to the stacking direction A.

[0024] In this regard, terms such as "above", "under", "top", "upper" and "bottom" refer to the orientation or direction as shown in the figures and as shown with respect to the stacking direction A. Thus, the height or thickness of the described elements is related to the stacking direction A, and the lateral direction B is oriented perpendicular to the stacking direction A (see FIGS. 1, 2 and 3).

[0025] The metal substrate structure 3 further comprises at least one blind hole 7 having a diameter d_bh of the circumscribed circle of the blind hole 7 that penetrates the metal bottom layer 19 and the insulating layer 18. Thus, at least one self-standing portion 171 of the metal top layer 17 is available. The terminal 4 and the self-standing portion 171 of the metal top layer 17 are intended to be connected by ultrasonic welding, for example, by an ultrasonic welding head 6 (not shown), and / or by laser welding by a laser beam 60 (not shown), with a diameter d_wc of the circumscribed circle of the welding connection portion 45. Thus, the self-standing portion 171 of the metal top layer 17 and the terminal 4 are materially bonded. The diameter d_wc of the circumscribed circle of the welding connection portion 45 is less than or equal to the diameter d_bh of the circumscribed circle of the blind hole 7. After the welding is completed, the at least one blind hole 7 is at least partially filled with a filling material 12 containing a dielectric material such as an epoxy resin, a thermoplastic resin, or any other electrically insulating material. The filling material 12 may contain fillers such as particles or fibers for improving or adjusting the thermal and / or mechanical properties.

[0026] Terminal 4 has an L-shape mainly comprising a terminal body 41 extending mainly in the stacking direction A and a terminal leg 42 extending mainly in the transverse direction B. The transverse direction B is substantially perpendicular to the stacking direction A. Alternatively, the terminal has a U-shape mainly comprising two terminal bodies 41 extending mainly in the stacking direction A and a terminal leg 42 extending mainly in the transverse direction B. Terminal 4 includes copper, aluminum and / or corresponding alloys and may realize the main terminal or auxiliary terminal of the semiconductor power module 10. The terminal leg 42 forms a plate with a thickness ranging from 0.5 mm to a maximum of 2.0 mm with respect to the stacking direction A. The terminal leg 42 can be partially or completely thinned to include a thickness of 0.5 mm or less. Therefore, the terminal leg 42 has a thickness of 0.25 - 2.0 mm.

[0027] The terminal leg 42 has a structure prepared for improved ultrasonic welding and / or laser welding. Such a welding structure can be realized by one or more slots, grooves, recesses and / or holes of the terminal leg 42 of the terminal 4, or by roughened or thinned areas (see Figure 2). Such a welding structure can be prepared on the uppermost surface 43 and / or the lowermost surface 44 of each terminal 4. A specific terminal structure can beneficially affect the ultrasonic welding process and / or the laser welding process and can contribute to the formation of a materially bonded weld joint. In particular, it is due to the reduced welding force and further reduces the thermal and mechanical impact of the welding process.

[0028] Alternatively or additionally, the whole of the terminal leg 42 is formed thinner than the body 41 of the terminal 4. For example, the thickness range of the thinned terminal leg 42 can be 0.3 - 0.8 times the thickness of the terminal body 41.

[0029] The welding process is performed on such a thinner part. Therefore, a reduced stress is provided for the ultrasonic welding process. Furthermore, since the amount of metal to be melted is reduced and the heat dissipation in the transverse direction is reduced, the laser energy required to realize the laser welding connection is reduced.

[0030] Furthermore, terminal 4 can be provided with a first coating layer 5 that partially or completely covers the uppermost surface 43 of the terminal leg portion 42 (see FIG. 3). The coating 5 is configured, for example, to face a laser beam 60 (not shown) that collides during laser welding, and is an antireflection coating that improves the irradiation efficiency of the laser beam 60. Terminal 4 can further be provided with a second coating layer 9 (not shown) that partially or completely covers the lowermost surface 44 of terminal 4.

[0031] The first and second coating layers 5, 9 can beneficially affect the ultrasonic welding process and / or the laser welding process. The first and second coating layers 5, 9 can, for example, protect the surface of terminal 4 from oxidation, and may also be made of, or contain, precious metals such as nickel, gold, silver, and / or other metals. The lower second coating layer 9 can also be useful for attaching terminal 4 to a metal top layer 17 that supports any type of welding process.

[0032] Such specifications of the material of the mating partner can contribute to a reliable and highly reliable welding process.

[0033] The thickness of the insulating layer 18 is 100 to 200 μm. The thickness of the circuit metallization formed by the top metal layer 17 is 150 to 500 μm. The thickness of the bottom metal layer 19 that can realize the base plate can be 2 to 5 mm, and it may also be configured to dissipate heat from the metal substrate structure 3 and the semiconductor power module 10. The insulating layer 18 can include an epoxy resin material, but other types of resins such as other thermosetting resins or thermoplastic resins are also possible. The resin material may include fillers such as inorganic particles or fibers to improve heat dissipation and insulation behavior. The insulating layer 18 forms a dielectric layer and can be realized as a resin sheet or prepreg sheet assembled between the top and bottom two metal plates that form the top metal layer 17 and the bottom metal layer 19. Such a metallization sheet or plate is bonded to the insulator of the dielectric resin layer 18, for example, by a lamination process. Next, the required metallization structure of the top metal layer 17 is performed by subsequent steps of masking and etching processes to locally remove the conductive metal, and the final metallization structure 17 can be created. Alternatively, the top metallization structure 17 can be formed by cutting or stamping, for example, before the formation of the completed metal substrate structure 3.

[0034] Alternatively, the insulating layer 18 can be formed by molding, for example, by injection, transfer, or compression molding. For such a molded insulating layer 18, the molding material realizes a pumpable material having predetermined material properties. The pumpable material is a liquid or viscous raw material of the resin layer to be formed. For example, the molding material is an epoxy and / or ceramic-based liquid. Alternatively or additionally, the raw material of the insulating layer 18 may be a thermosetting or thermoplastic resin material such as polyamide, PBT, or PET. Alternatively or additionally, the raw material of the insulating layer 18 includes an inorganic filler for improving the thermal conductivity and / or adjusting the CTE with respect to the metal top layer 17 and / or the metal bottom layer 19. The molded insulating layer 18 includes a resin-based dielectric material having a ceramic filler, for example, Al2O3, AlN, BN, Si3N4, or SiO2. For example, the insulating layer 18 is an epoxy containing a filler. The insulating layer 18 can also be based on other materials suitable for transfer, injection, or compression molding, or other applicable molding techniques, for example, bismaleimide, cyanate ester, polyimide, and / or silicone. Alternatively or additionally, the insulating layer 18 can include a ceramic material and / or a hydroset material, or a combination of two or more of the aforementioned components. The thickness of the insulating layer 18 has a value from 100 μm to a maximum of 200 μm.

[0035] The metal bottom layer 19 includes copper and / or aluminum and / or corresponding alloys. The circuit metallization formed by the metal top layer 17 includes copper and / or aluminum and / or corresponding alloys. Further, the metal top layer 17 may be partially or completely coated. The corresponding coating of the circuit metallization includes noble metals such as nickel and / or gold and / or silver, and / or other metals.

[0036] The dimensions and positioning of the welding connection part 45 of the terminal leg above the blind hole 7 are shown in the top view of Fig. 4. The terminal leg 42 (not shown in Fig. 4) can be positioned at the center or an eccentric position on the periphery above the blind hole 7. The diameter of the circumscribed circle of the terminal leg 42 (not shown in Fig. 4) may be larger than, smaller than, or the same as the diameter d_bh of the circumscribed circle of the blind hole 7. The shapes of the terminal leg 42 (not shown in Fig. 4) and the blind hole 7 can have any geometric shape such as a square, rectangle, circle, or other polygon. The diameter d_wc of the circumscribed circle of the welding connection part 45 of the terminal leg is equal to or less than the diameter d_bh of the circumscribed circle of the blind hole 7. Therefore, the area of the welding connection part 45 of the terminal leg is equal to or less than the cross-sectional area of the blind hole 7. Even if the terminal leg 42 (not shown in Fig. 4) is positioned slightly off-center with respect to the blind hole 7, no part of the welding connection part 45 is located above a part of the insulating layer 18 (not shown in Fig. 4).

[0037] The steps of a method for attaching the terminal 4 to the metal substrate structure 3 can follow the flowchart shown in Fig. 5. According to the embodiment shown in Fig. 1, in step S1, at least one terminal 4 is provided. The terminal 4 can be provided with the first and / or second coating layers 5, 9 on the topmost and / or bottommost surfaces of the terminal legs 43, 44. The first coating layer 5 is, for example, an anti-reflection coating for improving the laser welding process.

[0038] In step S2, the metal substrate structure 3 includes a metal top layer 17, a metal bottom layer 19, and an insulating layer 18 disposed therebetween. The coating layer can also be available at least locally on the surface of the metal substrate structure 3, particularly on the metal top layer 17.

[0039] In step S3, a blind hole 7 is provided that penetrates the metal bottom layer 19 and the insulating layer 18. Alternatively, the blind hole 7 may already be provided during the manufacture of the metal bottom layer 19 and the insulating layer 18 before step S1.

[0040] In an optional step S4, the opposing element 8 is introduced into the blind hole 7 that penetrates the metal bottom layer 19 and the insulating layer 18, providing mechanical support during the welding process and / or improved heat dissipation.

[0041] In a further step S5, the terminal 4 is welded to the self-supporting portion 171 of the metal top layer 17. Thereby, the terminal 4 is joined to the metal top layer 17 of the metal substrate structure 3 by ultrasonic welding with the ultrasonic welding head 6 and / or laser welding with the laser beam 60 or any other applicable welding method. A welded joint is formed between the terminal 4 and the metal top layer 17 by the welding process. Thus, the terminal 4 and the metal top layer 17 are firmly and materially joined. In the case of laser welding, the anti-reflection coating 5 partially or completely covers the topmost surface 43 of the terminal 4 facing the impinging laser beam 60, improving the laser welding process.

[0042] In a further optional step S6, if the opposing element 8 was introduced in step S4, the opposing element 8 is removed from the blind hole 7.

[0043] In a further optional step S7, the blind hole 7 is filled with a filling material 12 containing a dielectric material such as epoxy resin, thermoplastic resin or any other electrical insulating material.

[0044] In contrast to conventional substrates based on ceramic insulating sheets, the insulated metal substrate 3 consists of a relatively thick metal base 19 containing aluminum and / or copper and / or corresponding alloys, an insulating layer 18 based on a resin material, and a circuit metallization 17 containing aluminum and / or copper and / or corresponding alloys. The resin material used for the insulating layer 18 is typically an epoxy resin or another thermosetting resin containing a thermally conductive inorganic filler material. One advantageous component of such a filler material may be ceramic particles prepared from aluminum nitride (AlN), silicon nitride (Si3N4), boron nitride (BN), and / or aluminum oxide (Al2O3).

[0045] Mechanical, thermal, and / or thermo-mechanical shocks of an ultrasonic welding process and / or a laser welding process to the insulating layer 18 are reduced or suppressed by the implementation of the blind holes 7 that penetrate the metal bottom layer 19 of the metal substrate structure 3 and the insulating layer 18. Then, the welding connection 45 is prepared between the terminal leg 42 of the terminal 4 and the self-standing portion of the metal top layer 19, whereby the propagation of mechanical and thermal stresses into the metal substrate structure 3, and thus into the insulating layer 18, is reduced, and thus the mechanical and thermal stresses themselves are reduced. The blind holes 7 that penetrate the metal bottom layer 19 and the insulating layer 18 are provided prior to the ultrasonic welding and / or laser welding of the main terminal or auxiliary terminal 4.

[0046] The ultrasonic welding process is carried out in cooperation with the terminal 4, the blind hole 7, the opposing element 8, and the metal substrate structure 3. For example, the ultrasonic welding process is carried out at an ultrasonic frequency in the range of 10 to 100 kHz, for example 20 kHz. For example, the ultrasonic welding process is carried out with an amplitude ranging from 10 μm to a maximum of 100 μm. The ultrasonic welding process can be carried out with a predetermined mechanical pressure acting on the terminal leg 42 ranging from 100 N to a maximum of 1000 N.

[0047] Furthermore, the laser welding process can be configured to provide certain parameters that beneficially affect the formation of one or more welded joints. Thus, the laser beam 60 or corresponding laser source used for laser welding can be configured to provide an output of 300 to 3000 W. Alternatively or additionally, the laser beam or laser source for laser welding can be configured to provide a travel speed of 1 to 200 mm / s guided along the uppermost surface 43 of at least one terminal 4 facing the colliding laser beam 60. Thus, the welding need not be performed at only one limited point, and the laser spot of the laser beam providing the welding process can move at the aforementioned speed to provide a joint connection over a defined area. There may also be a plurality of small laser spots for the joint connection. The laser beam 60 can also be configured to oscillate at a predetermined frequency. Thus, the laser spot position can oscillate or sway at a frequency of up to 2 kHz. Such swaying may present an oscillation of the irradiation point position to prevent overly intense local heating and may occur in addition to the aforementioned laser movement and beneficially affect the welding process.

[0048] The described embodiments relate to ultrasonic welding and / or laser welding of power and auxiliary terminals 4 on an insulated metal substrate or insulated metal base plate realized by a metal substrate structure 3. The insulated metal substrate can be prepared by lamination or molding techniques. This can also be realized on a substrate structure based on alternative insulated metal substrate technologies, such as stamped and formed metal substrates. The ultrasonic welding and / or laser welding process is facilitated by stop holes 7 that penetrate the metal bottom layer 19 and the insulating layer 18 of the metal substrate structure 3.

[0049] The described embodiments of a method for attaching terminal 4 and / or for manufacturing a metal substrate structure 3 to which one or more terminals 4 are attached make it possible to reduce the risk of formation of cracks or damage in the insulating layer 18 by reducing thermal, mechanical, and / or thermo-mechanical shocks to the substrate structure. Thus, the method enables a stable semiconductor power module 10 with reliable operation, for example, also in high-voltage power module applications in a voltage range from 0.5 kV up to a maximum of 10.0 kV.

[0050] The embodiments shown in FIGS. 1 to 4 above represent exemplary embodiments of an improved metal substrate structure 3, a semiconductor power module 10, and a manufacturing method therefor, and thus they do not constitute a complete list of all embodiments. The actual arrangements and methods may differ, for example, from the embodiments shown with respect to the metal substrate structure 3 and the semiconductor power module 10.

Description of Reference Signs

[0051] Reference Sign 3 Metal Substrate Structure 4 Terminal 41 Terminal Body 42 Terminal Leg 43 Top Surface of Terminal Leg 44 Bottom Surface of Terminal Leg 45 Weld Connection of Terminal Leg 5 First Coating Layer 6 Ultrasonic Welding Head (not shown) 60 Laser Beam (not shown) 7 Stop Hole 8 Opposing Element 9 Second Coating Layer 10 Semiconductor Power Module 12 Filling Material 17 Metal Top Layer 171 Self-Supporting Portion of Metal Top Layer 18 Insulating Layer 19 Metal Bottom Layer A Lamination Direction B Lateral Direction d_bh Diameter of the circumscribed circle of the stop hole d_wc Diameter of the circumscribed circle of the welding connection part of the terminal leg S(i) Steps of a method for manufacturing a metal substrate structure for a semiconductor power module

Claims

1. A method for attaching a terminal (4) to a metal substrate structure (3) for a semiconductor power module (10), comprising: - providing at least one terminal (4); - a metal top layer (17); - a metal bottom layer (19), and - an insulating layer (18) disposed between the metal top layer (17) and the metal bottom layer (19); - providing the metal substrate structure (3) having the above; - providing at least one blind hole (7) penetrating the metal bottom layer (19) and the insulating layer (18), - positioning the at least one terminal (4) on the metal top layer (17) on the side opposite to the blind hole (7), - coupling the at least one terminal (4) to the metal top layer (17) by welding means. A method as described above.

2. The method according to claim 1, wherein the welding means is ultrasonic welding by an ultrasonic welding head (6).

3. The method according to claim 1, wherein the welding means is laser welding by a laser beam (60).

4. The method according to any one of the preceding claims, wherein a counter element (8) is introduced into the blind hole (7) during welding.

5. The method according to any one of the preceding claims, wherein after welding is completed, the at least one blind hole (7) is at least partially filled with a filling material (12) containing an electrically insulating material.

6. The method according to any one of the preceding claims, wherein the filling of the blind hole (7) is performed by dispensing or injecting the filling material (12).

7. - at least one metal substrate structure (3) comprising a metal top layer (17), a metal bottom layer (19), and an insulating layer (18); - at least one terminal (4); - at least one blind hole (7) penetrating the metal bottom layer (19) and the insulating layer (18), - A semiconductor power module (10) comprising: - the at least one terminal (4) is positioned on the metal top layer (17) on the side opposite to the blind hole (7) and coupled by welding means.

8. The terminal (4) comprises: - a terminal body (41); - a terminal leg (42) coupled to the terminal body (41) in an L-shape or U-shape and essentially perpendicular to the terminal body (41). The semiconductor power module (10) according to claim 7.

9. - The semiconductor power module (10) according to claim 8, wherein the size of the diameter (d_wc) of the circumscribed circle of the welding connection portion (45) of the terminal leg portion (42) is equal to or less than the diameter (d_bh) of the circumscribed circle of the stop hole (7).

10. - The semiconductor power module (10) according to any one of claims 7 to 9, wherein the terminal leg portion (42) has a thickness of 0.25 to 2.0 mm.

11. - The semiconductor power module (10) according to any one of claims 7 to 10, wherein the metal top layer (17) has a thickness of 150 to 500 μm.

12. - The semiconductor power module (10) according to any one of claims 7 to 11, wherein the insulating layer (18) has a thickness of 100 to 200 μm.

13. - The semiconductor power module (10) according to any one of claims 7 to 12, wherein the insulating layer (18) is made of a resin material.

14. - The semiconductor power module (10) according to claim 13, wherein the resin material used for the insulating layer (18) is a thermosetting resin containing a thermally conductive filler.

15. - The semiconductor power module (10) according to any one of claims 7 to 14, wherein the terminal leg portion (42) is welded to the metal top layer (17) using ultrasonic welding, laser welding, or another applicable welding method.

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