A method for manufacturing a metal substrate structure and a metal substrate structure for a semiconductor power module, and a semiconductor power module

Abstract

A metal substrate structure (10) for a semiconductor power module comprises a circuit metallization layer (11), a metal bottom layer (13) bonded to the circuit metallization layer (11), and an insulating dielectric layer (12) bonded to the circuit metallization layer (11) and the metal bottom layer (13) with respect to the stacking direction (A) and disposed between them. The circuit metallization layer (11) or the dielectric layer (12) forms at least locally the uppermost layer of the metal substrate structure (10), and the uppermost and bottommost layers (13) include fixing regions (18) configured to receive fixing elements (16) for fixing the metal substrate structure (10) to further components (14) of the semiconductor power module. At least the uppermost layer includes stress-relieving recesses (15).

Description

Technical Field

[0001] The present disclosure relates to a metal substrate structure and a corresponding method for manufacturing a metal substrate structure for a semiconductor power module. The present disclosure further relates to a corresponding semiconductor power module.

Background Art

[0002] Semiconductor power modules form technologies for low, medium, and high voltage applications, for example for fixing to a cooler or for being subjected to mechanical stress during thermal cycling. Thus, for example, mechanical or thermo-mechanical stress can cause the risk of delamination, voids or cracks in the module's encapsulation and the metal substrate. In this regard, preventing damage is generally a challenge. Japanese patent application JP2010034346A refers to a metal substrate having a circuit metallization layer with a fixed region, a bottom metal layer, and an insulating dielectric layer in between. Japanese patent application JP2006100640A refers to a metal substrate having a circuit metallization layer with a fixed region, a bottom metal layer, and an insulating dielectric layer in between. U.S. Patent Application US2019 / 157182A1 refers to a metal substrate having a metal bottom layer with a fixed region and an insulating dielectric layer.

Summary of the Invention

Means for Solving the Problems

[0003] Embodiments of the present disclosure relate to a stable metal substrate structure for a semiconductor power module with a reduced risk of damage occurring. Further embodiments of the present disclosure relate to providing a corresponding semiconductor power module and a method for manufacturing such a metal substrate structure.

[0004] According to one embodiment, a metal substrate structure for a semiconductor power module comprises a circuit metallization layer for conducting electrical signals, such as signal and / or current transfer. The metal substrate structure further comprises a bottom metal layer bonded to the circuit metallization layer, and an insulating dielectric layer bonded to the circuit metallization layer and the bottom metal layer with respect to the stacking direction of the metal substrate structure, and disposed between them. The circuit metallization layer or dielectric layer forms at least locally the top layer of the metal substrate structure, and the top layer, and possibly the bottom layer as well, comprises fixing regions configured to receive fixing elements for fixing the metal substrate structure to further components of the semiconductor power module, such as a cooler or heat sink.

[0005] The metal substrate structure further includes stress-relaxing recesses that penetrate the metallization layer and the dielectric layer and partially or completely enclose each fixed region at a predetermined distance. The fixed regions may also be referred to as fixed areas. In particular, the metal substrate structure further includes circuit regions. In particular, circuit regions are areas on which electrical components such as semiconductor chips and their electrical interconnections are located. The fixed regions and circuit regions are arranged side by side without overlap. The fixed regions are, for example, any region outside the circuit regions. The fixed regions are primarily for mechanical purposes.

[0006] By using the described configuration of the metal substrate structure, it is possible to reduce the risk of damage when it is attached, for example, to a cooler unit. One or more stress-relaxing recesses associated with the corresponding fixed area can contribute to blocking, preventing, or at least preventing the further formation of voids or cracks that may occur during the assembly of the metal substrate structure by the fixed elements. Furthermore, the described configuration can also contribute to preventing and / or preventing the delamination of the dielectric layer from the bottom metal layer. The stress-relaxing recesses function like a firewall, as further propagation of damage beyond the stress-relaxing recesses is prevented, or at least prevented.

[0007] According to one embodiment of the metal substrate structure, the fixing region includes a through-fixing opening configured to receive a fixing element, such as a screw or bolt. A stress-relieving recess is formed to partially or completely surround the fixing opening at a predetermined distance.

[0008] According to one embodiment of the metal substrate structure, stress-relieving recesses are confined by an uppermost layer in the form of a ring-shaped or funnel-shaped groove around each fixed region. Alternatively or additionally, stress-relieving recesses are conical or V-shaped uppermost layers with respect to a cross-section passing through the fixed regions and stress-relieving recesses along the lamination direction. Or, stress-relieving recesses may be confined by a rectangular or circular uppermost layer with respect to a cross-section passing through the fixed regions and stress-relieving recesses along the lamination direction.

[0009] The stress-relieving recesses penetrate the metallization layer and the dielectric layer. Each stress-relieving recess can completely or partially penetrate the top layer, and therefore the metallization layer and / or dielectric layer. Optionally, each stress-relieving recess can further partially penetrate the bottom metal layer.

[0010] According to a further embodiment of the metal substrate structure, the distance between the stress-relaxing recess and the associated fixed opening or fixed area is given in accordance with the dimensions of the fixed element and with respect to the required clamping force designed to be positioned in the fixed area.

[0011] According to a further embodiment of the metal substrate structure, stress-relaxing recesses are formed in regions that provide electrical insulation to local portions of the circuit metallization layer in contact with the fixed element.

[0012] According to a further embodiment of the metal substrate structure, the stress-relieving recess includes a predetermined depth along the lamination direction, which is 2.5 mm or less. The formation of the stress-relieving recess is configured to conform to the uppermost and / or lowermost layers of the metal substrate structure, and / or to the fastening elements intended to be used, and with respect to the required clamping force.

[0013] According to a further embodiment of the metal substrate structure, the stress-relaxing recess is formed by at least one of laser cutting, etching, and computer numerical control machining.

[0014] According to one embodiment, the semiconductor power module comprises a heat sink or cooler unit having a fixed area, e.g., a fixed opening, and one embodiment of the described metal substrate structure. The metal substrate structure is fixed to the cooler unit by fixing elements such as screws, bolts, springs and / or clamps, which are located in the fixed area of ​​the metal substrate structure, e.g., within or near the fixed opening, and in the fixed area of ​​the cooler unit.

[0015] Power semiconductor modules, which have a base plate on which a chip-equipped substrate is mounted, or an insulating metal substrate including a relatively thick metal plate, insulating layer, and circuit metallization, are typically attached to a cooler by screws or bolts. For this purpose, corresponding screw holes, openings, or recesses are provided in the base plate or insulating metal substrate.

[0016] The recognition in the context of this disclosure is that mechanically important locations occur in the vicinity of openings or adjacent to threaded or bolted joints, thereby creating, for example, a weakness in the package design. The described possible configurations of the metal substrate structure and one or more stress-relieving recesses make it possible to counteract and limit undesirable crack formation and / or delamination in the metal substrate structure due to pressures and mechanical stresses applied, particularly during assembly and / or operation including thermal cycling, mechanical shock, or vibration. The stress-relieving recesses act as barriers, preventing or at least reducing further propagation of cracks or delamination beyond the stress-relieving recesses.

[0017] According to one embodiment, a method for manufacturing one embodiment of a metal substrate structure includes providing a circuit metallization layer for conducting electrical signals, providing a metal bottom layer, and providing an insulating dielectric layer. The method further includes bonding the circuit metallization layer, the metal bottom layer, and the dielectric layer to each other such that the dielectric layer is bonded to the circuit metallization layer and the metal bottom layer with respect to the stacking direction of the metal substrate structure and positioned between them. The circuit metallization layer or the dielectric layer forms the uppermost layer of the metal substrate structure, at least locally. The method further includes forming or defining fixing regions in the uppermost and bottom layers, which are configured to receive fixing elements and fix the metal substrate structure to further components of a semiconductor power module. The method further includes forming stress-relaxing recesses that penetrate the metallization layer and the dielectric layer and at least partially enclose the fixing regions by a predetermined distance.

[0018] The step of forming stress-relieving recesses may include forming the stress-relieving recesses by laser cutting, etching, and computer numerical control machining, or at least one of any other applicable methods.

[0019] The step of providing a dielectric layer may include, for example, providing a resin sheet or forming an epoxy resin layer by molding. The resin sheet is typically filled with particles of dielectric material.

[0020] If the described semiconductor power module and the described manufacturing method include one embodiment of a metal substrate structure, or if they are related to the manufacture of one embodiment of a metal substrate structure, then the described features and properties of the metal substrate structure are also disclosed with respect to the semiconductor power module and the manufacturing method, and vice versa.

[0021] The fastening element can be implemented as a screw or bolt with an optional washer or spring washer. Alternatively or additionally, the fastening element may include a clamp or spring.

[0022] The stress-relieving recess is formed as a groove, and the position of the groove may be given so as to partially or completely enclose the fixing area of ​​the metal substrate. The groove can be located next to the fixing area or fixing opening. For example, the groove is located next to a semicircular notch or recess at the edge of the insulating metal substrate structure. The distance between the groove and the screw head or washer or spring washer or another fixing structure can have a value of, for example, within 1 to 15 mm. Other values ​​are also possible, especially depending on the size of the metal substrate structure. For example, the distance may include values ​​of 1 to 10 mm, 1 to 5 mm, or 1 to 2 mm.

[0023] The groove depth is predetermined and can partially or completely penetrate only the circuit metallization layer. Alternatively or additionally, the groove can partially or completely penetrate the insulating dielectric layer. Depending on which layer forms the top layer, the groove can partially or completely penetrate only the insulating layer, assuming there is no circuit metallization layer in its range. The bottom of the groove can also penetrate the bottom metal layer. The groove can also provide electrical insulation for metal patterns in contact with, for example, screws or bolts or clamp heads. The penetration depth can have a value of 2.5 mm or less, assuming the metallization layer has a maximum thickness of 2.0 mm in the lamination direction.

[0024] The cross-sectional shape of the stress-relaxing recess, defined by the restrictive contours of one or more layers of the metal substrate structure, can be a V-cut, or it can have a round, rectangular, or square shape.

[0025] The bottom metal layer of an insulating metal substrate structure can be made of or include copper, aluminum, iron, steel, or a corresponding alloy. The insulating dielectric layer can be made of or include epoxy resin typically filled with dielectric material particles, or another insulating material applicable to the lamination or molding process. The circuit metallization layer can be made of or include copper, aluminum, iron, steel, or a corresponding alloy.

[0026] The insulated metal substrate structure can include a relatively thick metal base forming a bottom metal layer, an insulating sheet of epoxy resin having an inorganic filler, and a circuit metallization layer. The metal plate can be completely covered by the insulating sheet and the circuit metallization, except for insulating grooves for insulating circuit patterns of different potentials. In particular, screws or bolts can be used as fixing elements for attaching the insulated metal substrate to a cooler unit or another component of a semiconductor power module.

[0027] The screws or bolts are inserted, for example, into corresponding holes or attached to recesses in the surrounding area. Here, the bottom surface of the screw head or an optional washer contacts the circuit metallization layer or the insulating sheet, applying pressure and / or torque to the substrate structure, so it is necessary to also consider at least the pressure and / or lateral force during the fixing procedure and / or during operation. Considering conventional power modules, such pressure and / or torque can lead to uncontrolled delamination or cracking of the layered structure of the insulated metal substrate, which can extend into the circuit areas of chips and terminals where high voltage levels are available. Therefore, delamination or cracking can significantly reduce the insulation properties and reliability of the insulated metal substrate. By using the described configuration of a metal substrate structure including stress-relieving recesses specially designed and arranged in the vicinity of the screw holes, it is possible to counteract and / or locally limit the aforementioned adverse effects so that important substrate areas such as the circuit area are not affected.

[0028] Exemplary embodiments of a semiconductor power package will be described below using schematic diagrams and reference numerals. The figures show the following.

Brief Description of the Drawings

[0029] [Figure 1] Embodiments of a metal substrate structure for a semiconductor power module in respective cross-sectional side views. [Figure 2]Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 3] Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 4] Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 5] Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 6] Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 7] Embodiments of a metal substrate structure for a semiconductor power module in each cross-sectional side view. [Figure 8] Flowchart of a method for manufacturing an embodiment of a metal substrate structure. [Figure 9] A top view of one embodiment of a metal substrate structure. [Figure 10] A top view of a further embodiment of the metal substrate structure. [Modes for carrying out the invention]

[0030] The attached drawings are included for further understanding. Please understand that the embodiments shown in the drawings are illustrative and not necessarily drawn to a specific scale. The same reference numerals indicate elements or components having the same function. The descriptions of elements or components in each of the following drawings will not be repeated insofar as they correspond to each other in terms of their function in different drawings. For clarity, elements may not be represented by the same reference numeral in all drawings.

[0031] Figures 1 to 7 show different embodiments of the metal substrate structure 10 for semiconductor power modules in cross-sectional side views.

[0032] The metal substrate structure 10 comprises a circuit metallization layer 11, a bottom metal layer 13 bonded to the circuit metallization layer 11, and an insulating dielectric layer 12 bonded to the circuit metallization layer 11 and the bottom metal layer 13 with respect to the stacking direction A of the metal substrate structure 10, and disposed between them. The stacking direction A may be oriented perpendicular to the lateral directions B and C of the metal substrate structure 10.

[0033] A circuit metallization layer 11 (see Figures 1-6) or dielectric layer 12 (see Figure 7) forms at least locally the uppermost layer of the metal substrate structure 10, and the uppermost and lowermost layers 13 include fixing regions 18 configured to receive fixing elements 16 for fixing the metal substrate structure 10 to further components of the semiconductor power module. The further components can be realized as a heat sink or cooler unit 14, as shown in Figures 1-7. The cooler unit 14 includes fixing ranges 19, and the metal substrate structure 10 is fixed to the cooler unit 14 by fixing elements 16 located in the fixing regions 18 of the metal substrate structure 10 and the fixing ranges 19 of the cooler unit 14. At least the uppermost layer includes stress-relieving recesses 15 that partially or completely enclose each fixing region 18 at a predetermined distance.

[0034] By using the above-described configuration of the metal substrate structure 10, it is possible to reduce the risk of significant damage when it is attached to the cooler unit 14. One or more stress-relieving recesses 15 associated with the corresponding fixed areas 18, 19 can contribute to blocking, preventing, or at least preventing the further formation of gaps or cracks that may occur during the assembly of the metal substrate structure 10 by the fixed elements 16. The progression of damage to critical areas, particularly the circuit area 20, is prevented by the stress-relieving recesses 15, and as a result, the damage is limited to particularly specific areas. Furthermore, the described configuration can also contribute to preventing the delamination of the dielectric layer 12 from the metal bottom layer 13 and / or the delamination of the metallization layer 11 from the dielectric layer 12.

[0035] According to Figures 1 and 3-7, the fixing area 18 of the metal substrate structure 10 and the fixing area 19 of the cooler unit 14 include their respective fixing openings 17, and the fixing elements 16 extend into the fixing openings 17 and are formed as screws or bolts that securely fix the metal substrate structure 10 to the cooler unit 14.

[0036] Figure 2 shows a different embodiment having a fixing element 16 formed as a clamp, and the metal substrate structure 10 is fixed to the cooler unit 14 by the clamp. Therefore, there is no need to provide fixing openings in the fixing area 18 of the metal substrate structure 10 and the fixing range 19 of the cooler unit 14.

[0037] The stress-relieving recess 15 may include a V-cut cross-sectional shape (see Figures 1, 2, and 7) that can be formed in the metal substrate structure 10, for example, by laser processing. Alternatively, the stress-relieving recess 15 may be limited by the corresponding layers 11, 12, and / or 13 of the metal substrate structure 10 and may include a conical shape (see Figure 3), a round or circular shape (see Figure 4), or a rectangular shape (see Figures 5 and 6). Exemplary top views are shown in Figures 9 and 10.

[0038] The stress-relieving recess 15 can be formed so as to be limited by one or more of the metallization layer 11, dielectric layer 12, and bottom layer 13 of the metal substrate structure 10. As shown in Figures 1 to 3, the stress-relieving recess 15 is formed as a V-cut or conical groove that completely penetrates the metallization layer 11 and dielectric layer 12, and partially penetrates the bottom layer 13.

[0039] As shown in Figure 4, the stress-relaxing recess 15 is formed as a ring-shaped groove that completely penetrates the metallization layer 11 and partially penetrates the dielectric layer 12, but does not extend into the bottom layer 13.

[0040] According to Figure 5, the stress-relaxing recess 15 is formed as a rectangular groove that partially penetrates the metallization layer 11 and does not extend into the dielectric layer 12 or the bottom layer 13. According to Figure 6, the stress-relaxing recess 15 is also formed as a rectangular groove, but the groove completely penetrates the metallization layer 11 and the dielectric layer 12 and extends deeply into the bottom layer 13.

[0041] Therefore, the depth of the stress-relieving recess 15 may vary depending on its intended location within the metal substrate structure 10, and / or depending on the respective thicknesses of layers 11, 12, and / or 13 of the metal substrate structure 10, and / or depending on the dimensions of, for example, the fixing element 16, and the applied force or pressure. This also applies to other configurations of the stress-relieving recess 15.

[0042] The distance between the stress-relieving recess 15 and the fixing element 16 is given along the lateral direction B and can be, for example, within 1 to 2 mm. This distance can point to the central axis of the stress-relieving recess 15 and the fixing element 16, respectively. Alternatively, the distance can point to the closest points of the stress-relieving recess 15 and the fixing element 16 along the lateral direction B, or it can point to the average distance. Thus, referring to Figure 1, the distance between the inner upper edge of the V-cut stress-relieving recess 15 and the outer surface of the screw or bolt head can be given a predetermined value.

[0043] As long as the stress-relieving recess 15 encloses at least half of the fixed element 16, the stress-relieving recess 15 can be formed symmetrically around the fixed element 16, as shown in Figures 1 to 3 and Figures 5 to 7. Alternatively, the stress-relieving recess 15 can be formed asymmetrically with respect to the fixed element 16, as shown in Figure 4.

[0044] Therefore, the positioning of the stress-relieving recess 15 and the distance between the stress-relieving recess 15 and the fixing element 16 may vary, for example, depending on its intended location within the metal substrate structure 10, and / or depending on the respective thicknesses of layers 11, 12, and / or 13 of the metal substrate structure 10, and / or depending on the dimensions of the fixing element 16. This also applies to other configurations of the stress-relieving recess 15 and the fixing element 16.

[0045] As shown in the top view of Figure 9, the metal substrate structure 10 includes a circuit region 20 located, for example, in the central area of ​​the metal substrate structure 10. The fixed region 15 is located outside the circuit region 20. In the operational ready state, electrical components such as semiconductor chips or devices are placed within the circuit region 20 and electrically connected. As shown exemplary in relation to the fixed region in the upper left, the fixed opening 17 may be surrounded by a plurality of stress relief recesses 15. This is, of course, also possible with other fixed openings 17. It is possible to arrange any feasible number of stress relief recesses 15, for example, two, three, or four stress relief recesses 15 arranged concentrically around the fixed opening or in other arrangements.

[0046] Figure 10 shows an embodiment in which the stress-relieving recess 15 surrounds the circuit region 20. For example, the embodiments of Figures 9 and 10 can be combined such that the stress-relieving recess 15 surrounds the fixed opening 17 and further stress-relieving recess 15 surrounds the circuit region 20. Only the stress-relieving recess 15 surrounding the fixed opening 17, or only the stress-relieving recess 15 surrounding the circuit region 20, may be provided. Any feasible number of stress-relieving recesses 15 can surround the circuit region 20 (partially or completely), for example, two, three, or four stress-relieving recesses 15 arranged in layers around the circuit region 20.

[0047] Figure 8 shows a flowchart of a method for manufacturing an embodiment of the metal substrate structure 10. In step S1, a circuit metallization layer 11, a bottom metal layer 13, and an insulating dielectric layer 12 may be provided. For example, these layers 11-13 are provided with a given fixing opening 17 for receiving screws or bolts.

[0048] In step S2, the circuit metallization layer 11, the metal bottom layer 13, and the dielectric layer 12 are bonded to each other so that the dielectric layer 12 is bonded to the circuit metallization layer 11 and the metal bottom layer 13 and positioned between them.

[0049] In step S3, one or more stress-relaxing recesses 15 are formed in the circuit metallization layer 11 and / or dielectric layer 12, and optionally partially in the bottom metal layer 13. The step of forming the stress-relaxing recesses 15 in at least the top layer can be carried out by laser cutting and / or etching and / or computer numerical control machining.

[0050] The described manufacturing process enables the realization of a stable and resistant metal substrate structure 10, which can reduce the risk of damage formation during mounting, particularly during operation including thermal cycling and mechanical shock or vibration. Thus, the described embodiments can contribute to reducing the further formation of voids or cracks to at least as limited damage as possible, and / or the delamination of the dielectric layer 12 to a specific range. The stress relaxation recess 15 acts like a firewall to protect the circuit area 20, as it prevents, or at least hinders, further propagation of damage into the circuit area 20 beyond the stress relaxation recess 15.

[0051] Sufficient pressure applied to the surface of the mounted insulating metal substrate structure 10 by screw heads or clamps is necessary to achieve a proper thermal interface between the back surface of the metal substrate structure 10 and the cooler unit 14. The screw heads can be in direct contact with the upper metallization layer 11, or optional washers and / or spring washers can be placed between the screw heads and the upper metallization layer 11. Thus, mechanical stress on the metal substrate structure 10 cannot be avoided, especially in the vicinity of the fixed elements.

[0052] The described embodiments of the metal substrate structure 10 and its stress-relieving recess 15 can enable the limitation and control of the progression of mechanical stress or damage to a specific range. The stress-relieving recess 15 forms a recess or groove applied to the upper surface of the insulating metal substrate structure 10, which at least partially surrounds the location of a screw hole, or screw head, or an optional washer, at a specific relative distance. If the pressure and / or torque applied by the screw head or bolt or clamp causes delamination and / or cracking, the propagation of delamination or cracking is blocked or at least hindered by the stress-relieving recess 15. Since further propagation beyond the stress-relieving recess 15 is prevented or at least hindered, the stress-relieving recess 15 acts like a firewall.

[0053] The described configuration of the metal substrate structure 10 offers several advantages, considering the mounting of the corresponding power semiconductor module to the cooler unit 14. The insulating metal substrate structure 10 is a cost-competitive solution, particularly for low-voltage class power modules. The proposed metal substrate structure 10 counteracts the adverse effects of delamination and / or crack formation caused by pressure and / or torque applied by the fixing element 16 by clamping or screwing. The stress relief recesses act like a firewall, preventing, or at least hindering, further propagation of damage beyond the stress relief recesses. If a laser cutting process is used to form the stress relief recesses 15, the preparation of the corresponding grooves adjacent to the screw positions can be integrated, for example, into the preparation process of the V-cut grooves used for piecemaking of the substrate. Nevertheless, the described configuration of the metal substrate structure 10 is applicable to all low-voltage products and further products when the use of an insulating metal substrate is planned. [Explanation of symbols]

[0055] Reference sign 10 Metal substrate structure 11. Metallization layer 12 Dielectric layer 13. Bottom metal layer 14 Cooler Unit 15 Stress relaxation recess 16 fixed elements 17 Fixed opening 18 Fixed area 19 Fixed range 20 circuit area A Stacking direction B Horizontal C Lateral direction Each step of the method for manufacturing an S(i) molded power module

Claims

1. A metal substrate structure (10) for a semiconductor power module, - A circuit metallization layer (11) for conducting electrical signals, - The bottom metal layer (13) bonded to the circuit metallization layer (11), - The metal substrate structure (10) comprises an insulating dielectric layer (12) bonded to the circuit metallization layer (11) and the bottom metal layer (13) with respect to the stacking direction (A) of the metal substrate structure (10), and disposed between them. The circuit metallization layer (11) or the insulating dielectric layer (12) forms at least locally the uppermost layer of the metal substrate structure (10), The uppermost layer and the lowermost metal layer (13) include a fixing region (18) configured to receive fixing elements (16) for fixing the metal substrate structure (10) to further components of the semiconductor power module. The stress-relaxing recess (15) is a metal substrate structure (10) that penetrates the circuit metallization layer (11) and the insulating dielectric layer (12).

2. The metal substrate structure (10) according to claim 1, wherein the stress-relaxing recess (15) at least partially surrounds each of the fixed regions (18) by a predetermined distance.

3. The metal substrate structure (10) according to claim 2, wherein the fixing region (18) includes through-fixing openings (17) configured to receive the fixing elements (16), and the stress-relieving recesses (15) at least partially surround each of the through-fixing openings (17) by a predetermined distance.

4. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recesses (15) are limited by the uppermost layer in the form of a ring-shaped or funnel-shaped groove around each of the fixed regions (18).

5. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relieving recess (15) is limited by the uppermost layer which is conical or V-shaped in cross-section with respect to the fixed region (18) and the stress-relieving recess (15) along the stacking direction (A).

6. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relieving recess (15) is limited by the uppermost layer which has a rectangular or circular shape in cross-section with respect to the fixed region (18) and the stress-relieving recess (15) along the stacking direction (A).

7. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recess (15) partially penetrates the bottom metal layer (13) further.

8. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the distance between the stress-relieving recess (15) and the fixing region (18) associated with the stress-relieving recess (15) is given in accordance with the dimensions of the fixing element (16) which is designed to be positioned within the fixing region (18).

9. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recess (15) is formed in a region that provides electrical insulation to a local portion of the circuit metallization layer (11) that is in contact with the fixed element (16).

10. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recess (15) has a predetermined depth along the stacking direction (A) which is 2.5 mm or less.

11. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recess (15) is formed by at least one of laser cutting, etching, and computer numerical control machining.

12. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relaxing recess (15) at least partially surrounds the circuit region (20) by a predetermined distance.

13. The metal substrate structure (10) according to any one of claims 1 to 3, wherein the stress-relieving recess (15) comprises a plurality of recesses.

14. It is a semiconductor power module, - A cooler unit (14) having a fixed range (19), A semiconductor power module comprising a metal substrate structure (10) according to any one of claims 1 to 3, wherein the metal substrate structure (10) is fixed to the cooler unit (14) by fixing elements (16) arranged in the fixing region (18) of the metal substrate structure (10) and the fixing range (19) of the cooler unit (14).

15. The semiconductor power module according to claim 14, wherein the fixing element (16) comprises at least one of a screw, a bolt, a clamp, and a spring.

16. A method for manufacturing a metal substrate structure (10) for a semiconductor power module, - To provide a circuit metallization layer (11) for conducting electrical signals, - To provide the bottom metal layer (13), - To provide an insulating dielectric layer (12), - The insulating dielectric layer (12) is bonded to the circuit metallization layer (11) and the bottom metal layer (13) with respect to the stacking direction (A) of the metal substrate structure (10), and the circuit metallization layer (11), the bottom metal layer (13), and the insulating dielectric layer (12) are bonded to each other so that the insulating dielectric layer (12) is bonded to the circuit metallization layer (11) and the bottom metal layer (13) with respect to the stacking direction (A) of the metal substrate structure (10), and the circuit metallization layer (11) or the insulating dielectric layer (12) forms at least locally the top layer of the metal substrate structure (10). - Forming or defining a fixed region (18) in the uppermost layer and the lowermost metal layer (13), which are configured to receive a fixed element (16) and fix the metal substrate structure (10) to further components of the semiconductor power module, A method comprising: forming stress-relaxation recesses (15) penetrating the circuit metallization layer (11) and the insulating dielectric layer (12).

17. The step of forming the stress-relieving recess (15) in at least the uppermost layer is: The method according to claim 16, comprising forming the stress-relieving recess (15) by at least one of laser cutting, etching, and computer numerical control machining.

18. The step of forming the stress-relieving recess (15) in at least the uppermost layer is: The method according to claim 16 or 17, comprising forming the stress-relieving recess (15) such that the stress-relieving recess (15) at least partially surrounds the fixed area (18) and / or the circuit area (20) by a predetermined distance.

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