Insulating multi-layer Clip applied to power module and preparation method of insulating multi-layer Clip

Abstract

The invention discloses an insulating multi-layer Clip applied to a power module and a preparation method of the insulating multi-layer Clip, aging and layering risks of a traditional adhesive are eliminated through an adhesive-free laminated structure of the insulating multi-layer Clip, heat resistance, chemical resistance and long-term reliability of a product are improved, and meanwhile, an adhesive layer is omitted, so that the overall thickness of the product is thinner and more flexible; through the connection of deep drawing forming and the surface silver / nickel plating process, the three-dimensional assembly requirement of the insulation multi-layer Clip is met, and the conductive performance and the contact reliability of the circuit are improved. Multiple alignment errors are avoided through a one-time pressing process, the interlayer alignment precision is extremely high, the thickness of the dielectric layer is uniform, and the electrical performance consistency is good; the size precision and the circuit integrity of the product are guaranteed through the working procedures of drilling, etching, laser cutting and the like in combination with the precise temperature control and positioning technology. The method can be applied to the technical field of chip packaging.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, and in particular to an insulating multilayer clip for power modules and its fabrication method. Background Technology

[0002] As electronic products become thinner, lighter, and more flexible, flexible printed circuit boards (PCBs) are widely used in consumer electronics, automotive electronics, and medical devices. Automotive electronics, in particular, places higher demands on the reliability of PCBs. In traditional PCB manufacturing, the bonding between polyimide (PI) material and copper foil typically requires adhesives. This process suffers from problems such as insufficient bonding strength, poor high-temperature resistance, and complex procedures.

[0003] In existing technologies, although there are solutions that use thermoplastic polyimide (TPI) to replace traditional adhesives, there are still problems in practical applications, such as difficulty in controlling the thickness of the TPI layer, easy generation of bubbles and delamination during high-temperature pressing, and insufficient laser cutting precision, which limit the performance improvement and application expansion of flexible printed circuit boards.

[0004] The above problems urgently need to be addressed. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide an insulating multilayer clip for power modules and its preparation method. The adhesive-free lamination structure of the insulating multilayer clip eliminates the aging and delamination risks associated with traditional adhesives, thereby improving the heat resistance, chemical resistance, and long-term reliability of flexible printed circuit board products.

[0006] The first technical solution adopted in this invention is: An insulating multilayer clip for use in power modules, the insulating multilayer clip comprising a plurality of copper layers and a plurality of TPI modified layers alternately stacked along the thickness direction, the copper layers having a thickness of 100-300 μm, the TPI modified layers having a thickness of 50-100 μm, the copper layers being used to form circuit signal transmission paths, and adjacent copper layers being bonded together with insulation through the TPI modified layers, the TPI modified layers being made of polyimide through material modification treatment.

[0007] The second technical solution adopted in this invention is: A method for fabricating a multilayer insulating clip for a power module, comprising the following steps: TPI films are obtained by modifying both sides of polyimide films using one or more methods, including plasma treatment, excimer laser microprocessing, and chemical grafting modification. The copper foil and the TPI film are stacked in a preset alternating stacking pattern to obtain a pre-stacked structure. The pre-stacked structure is then pressed under high temperature, high pressure and vacuum conditions to obtain an integrated composite large board. The integrated composite board is drilled and copper plated to obtain an electroplated composite board; The upper and lower surfaces of the electroplated composite board are respectively coated with dry film, exposed and developed, and etched and stripped to obtain a composite board with circuit patterns. The composite board with circuit patterns is divided into multiple unit boards; The unit board is deep-drawn according to the preset three-dimensional shape of the product to obtain a three-dimensional flexible circuit structure. Selective chemical silver / nickel plating or electroplating silver / nickel plating is performed on the electrical contact area and / or functional area of ​​the three-dimensional flexible circuit structure to obtain the insulating multilayer Clip.

[0008] Furthermore, in one embodiment of the present invention, the material modification treatment is used to roughen the two sides of the polyimide film at the microscopic level, increase the surface area and reactive sites of the two sides of the polyimide film, and also to break the imide rings in the polyimide molecular chains on the two sides of the polyimide film, and introduce reversible crosslinking points to transform the polyimide film into thermoplastic behavior.

[0009] Furthermore, in one embodiment of the present invention, the pressing process is used to cause the TPI film to undergo micro-flow under high temperature and high pressure, thereby causing the molecular chains of the TPI film to form physical intercalation and chemical bonding with the surface of the copper foil.

[0010] Furthermore, in one embodiment of the present invention, the drilling and copper plating process performed on the integrated composite board to obtain the electroplated composite board specifically includes: Drill holes at predetermined positions on the integrated composite panel to create multiple through holes penetrating the integrated composite panel; The integrated composite board after drilling is subjected to descaling, activation, and chemical copper plating to form a conductive thin layer. The integrated composite board is electroplated throughout, so that the copper layer on the hole wall of the through hole reaches a preset thickness, thus obtaining the electroplated composite board.

[0011] Furthermore, in one embodiment of the present invention, the process of applying dry film, exposing and developing, and etching and stripping the upper and lower surfaces of the electroplated composite board to obtain a composite board with circuit patterns specifically includes: The upper and lower surfaces of the electroplated composite plate are coated or covered with a photo-resistant dry film. The preset circuit image is transferred onto the photoresist dry film using an exposure machine, and the copper area that needs to be etched away is exposed after development. The exposed copper areas are etched using an etching solution, and excess photoresist is removed by photo-irradiation to obtain the composite board with circuit patterns.

[0012] Furthermore, in one embodiment of the present invention, the step of deep drawing the unit board according to a preset three-dimensional product shape to obtain a three-dimensional flexible circuit structure specifically includes: The corresponding hydraulic / pneumatic control timing is determined based on the three-dimensional shape of the product. The unit board is placed in a hydraulic / pneumatic forming equipment, and under heating conditions, the unit board is gradually or in one step drawn according to the hydraulic / pneumatic control sequence to obtain the three-dimensional flexible circuit structure.

[0013] Furthermore, in one embodiment of the present invention, when the electrical contact area and / or functional area are selectively electrolessly plated with silver or electroplated with silver, the corresponding silver plating thickness is 0.5-5 μm; when the electrical contact area and / or functional area are selectively electrolessly plated with nickel or electroplated with nickel, the corresponding nickel plating thickness is 1-3 μm.

[0014] The beneficial effects of this invention are as follows: This invention provides an insulating multilayer clip for power modules and its preparation method. The adhesive-free lamination structure of the insulating multilayer clip eliminates the aging and delamination risks associated with traditional adhesives, improving the product's heat resistance, chemical resistance, and long-term reliability. Simultaneously, eliminating the adhesive layer results in a thinner and more flexible overall product. The integrally formed substrate structure has low internal stress, and combined with subsequent precise heating and deep drawing processes, it can achieve complex and stable three-dimensional structures, meeting the requirements of more complex three-dimensional circuits. The deep drawing process, combined with surface silver / nickel plating, not only meets the three-dimensional assembly requirements of the insulating multilayer clip but also improves the circuit's conductivity and contact reliability. The single-stage lamination process avoids multiple alignment errors, resulting in extremely high interlayer alignment accuracy, uniform dielectric layer thickness, and good electrical performance consistency. The combination of drilling, etching, and laser cutting processes with precise temperature control and positioning technology ensures the product's dimensional accuracy and circuit integrity. The overall manufacturing process is compact, reducing the number of laminations and material usage, and is more environmentally friendly as it does not use organic adhesives. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a multilayer insulating clip applied to a power module, provided by an embodiment of the present invention. Figure 2A flowchart illustrating the steps of a method for fabricating a multilayer insulating clip for a power module, as provided in an embodiment of the present invention; Figure 3 A schematic diagram of an integrated composite panel provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an electroplated composite large plate provided in an embodiment of the present invention; Figure 5 A schematic diagram of a composite board with circuit patterns provided in an embodiment of the present invention; Figure 6 A schematic diagram of a unit board provided in an embodiment of the present invention; Figure 7 A schematic diagram of a three-dimensional flexible circuit structure provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of an insulating multilayer Clip after silver / nickel plating, provided in an embodiment of the present invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0017] In the description of this invention, "multiple" means two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or the order in which the indicated technical features are presented. Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and not for limiting the invention.

[0018] In the traditional manufacturing process of flexible printed circuit boards, adhesives are usually required to bond polyimide (PI) material to copper foil. This process has problems such as insufficient bonding strength, poor high-temperature resistance, and complex process flow.

[0019] While existing technologies have explored the use of thermoplastic polyimide (TPI) to replace traditional adhesives, practical applications still face challenges such as difficulty in controlling TPI layer thickness, the potential for air bubbles and delamination during high-temperature lamination, and insufficient laser cutting precision. These issues limit the performance improvement and application expansion of flexible printed circuit boards (PCBs). Furthermore, existing flexible printed circuit board products also suffer from the following problems: 1) Interlayer bubbles and warping are prone to occur during the lamination process of multi-layer structures; 2) Defects such as burrs and cracks are easily generated during the forming process; 3) Uneven copper layer thickness on the hole wall during through-hole fabrication affects the reliability of electrical connections; 4) The low accuracy of graphic transfer makes it difficult to control the line width and spacing.

[0020] To address the aforementioned technical problems, this invention proposes an insulating multilayer clip for power modules and its fabrication method. It should be noted that the insulating multilayer clip of this invention is a multilayer flexible circuit structure with the corresponding functions of a flexible printed circuit board.

[0021] Reference Figure 1 This invention provides an insulating multilayer clip for use in power modules. The insulating multilayer clip includes several copper layers and several TPI modified layers that are alternately stacked along the thickness direction. The thickness of the copper layers is 100-300 μm, and the thickness of the TPI modified layers is 50-100 μm. The copper layers are used to form circuit signal transmission paths. Adjacent copper layers are bonded together with insulation through the TPI modified layers. The TPI modified layers are made of polyimide through material modification treatment.

[0022] Specifically, the insulating multilayer Clip of this invention comprises several copper layers and several TPI modified layers, with the copper layers and TPI modified layers alternately stacked to achieve the desired effect. Figure 1 Taking the three-layer structure shown as an example, from top to bottom, they are as follows: First copper layer 11: Electrolytic copper foil with a thickness of 100-300μm and a surface with micro-roughening treatment is used to form the circuit signal transmission path; TPI modified layer 12: Made of polyimide (PI) through plasma modification and deformation treatment, with a thickness of 50-100μm, it has excellent flexibility, high temperature resistance and adhesion to copper layers, and serves as an insulating adhesive layer for the upper and lower copper layers. The second copper layer 13 has the same material and thickness as the first copper layer 11, forming a symmetrical structure and improving the overall structural stability and conductivity balance of the insulating multilayer Clip.

[0023] The three-layer structure is tightly integrated, with an overall thickness that can be controlled between 250-700μm, a flexible bending radius of 0.3-1.0mm, and a temperature resistance range of -55℃ to 200℃, meeting the requirements for use in harsh environments.

[0024] It should be noted that the insulating multilayer Clip of the present invention is not limited to... Figure 1 The three-layer structure shown can be stacked to form a multi-layer structure according to actual needs, and there is no fixed requirement for the order of the copper layer and the TPI modified layer.

[0025] Reference Figure 2 This invention provides a method for fabricating a multilayer insulating clip for power modules, comprising the following steps: S101. The double sides of the polyimide film are modified by one or more of the following methods: plasma treatment, excimer laser microprocessing, and chemical grafting modification, to obtain a TPI film. S102. Copper foil and TPI film are stacked in a preset alternating stacking manner to obtain a pre-stacked structure. The pre-stacked structure is pressed under high temperature, high pressure and vacuum environment to obtain an integrated composite board. S103. Drilling and copper plating are performed on the integrated composite board to obtain an electroplated composite board. S104. Dry film is applied to the upper and lower surfaces of the electroplated composite board, and exposure and development, as well as etching and film removal are performed to obtain a composite board with circuit patterns. S105. Divide the composite board with circuit patterns into multiple unit boards; S106. The unit board is stretched and formed according to the preset three-dimensional shape of the product to obtain a three-dimensional flexible circuit structure. S107. Selectively chemically plate silver / nickel or electroplat silver / nickel to the electrical contact area and / or functional area of ​​the three-dimensional flexible circuit structure to obtain an insulating multilayer Clip.

[0026] The method for preparing the insulating multilayer Clip according to an embodiment of the present invention will be further described below with reference to the accompanying drawings.

[0027] As a further optional implementation, the material modification treatment is used to roughen the two sides of the polyimide film at the microscopic level, increase the surface area and reactive sites of the two sides of the polyimide film, and also to break the imide rings in the polyimide molecular chains on the two sides of the polyimide film, and introduce reversible crosslinking points to transform the polyimide film into thermoplastic behavior.

[0028] Specifically, a standard-sized polyimide (PI) film is provided in advance, and both sides of the PI film are pre-shaped using one or a combination of methods, including plasma treatment, excimer laser microprocessing, and chemical grafting modification. This process roughens the PI surface at the microscopic level, increasing its surface area and reactive sites; partially breaks the imide rings in the PI molecular chain, introducing reversible crosslinking points or transforming it into thermoplastic behavior, thereby generating a modified PI film (TPI film), i.e., a TPI interlayer material.

[0029] As a further optional implementation, the lamination process is used to cause the TPI film to undergo micro-flow under high temperature and high pressure, thereby enabling the molecular chains of the TPI film to form physical intercalation and chemical bonding with the surface of the copper foil.

[0030] Specifically, taking a three-layer structure as an example, such as Figure 3 As shown, the pretreated TPI film 21 is used as the intermediate layer, and copper foil 22 is coated on both the top and bottom surfaces to form a three-layer pre-overlapped structure of "copper foil-TPI-copper foil". This structure is then placed in a vacuum hot press and pressed under high temperature, high pressure, and vacuum conditions. Through the microscopic flow of the TPI layer under high temperature and high pressure, its molecular chains form a strong physical intercalation and chemical bond with the copper foil surface, thereby forming a structure as shown in the diagram. Figure 3 The image shows an integrated composite panel without adhesive.

[0031] As a further optional implementation, the integrated composite board is drilled and copper-plated to obtain an electroplated composite board, which specifically includes: Drill holes at predetermined positions on the integrated composite panel to create multiple through holes that penetrate the integrated composite panel. After drilling, the integrated composite board undergoes descaling, activation, and chemical copper plating to form a conductive thin layer. The integrated composite board is electroplated throughout to achieve a preset copper layer thickness on the walls of the through holes, thus obtaining the electroplated composite board.

[0032] Specifically, such as Figure 4 As shown, on the laminated integrated composite board, through holes 23 are processed by laser drilling or mechanical drilling to penetrate the upper and lower copper foils 22 and TPI film 21. The board after drilling is de-smeared, activated, and chemically deposited with copper to form a conductive thin layer. Then, the entire board is electroplated to thicken the copper layer so that the copper layer on the hole wall reaches the specified thickness, so as to achieve a reliable electrical connection between the upper and lower copper layers, and finally obtain the electroplated composite board.

[0033] As a further optional implementation, the upper and lower surfaces of the electroplated composite board are respectively coated with dry film, exposed and developed, and etched and stripped to obtain a composite board with circuit patterns, specifically including: Apply or coat photoresist dry film to the upper and lower surfaces of the electroplated composite plate; The preset circuit image is transferred onto a photoresist dry film using an exposure machine, and the copper area that needs to be etched away is exposed after development. The exposed copper areas are etched using an etching solution, and excess photoresist is removed by photo-irradiation to obtain a composite board with circuit patterns.

[0034] Specifically, the following processes are performed on the upper and lower surfaces of the electroplated composite plate: 1) Applying dry film: Coating or applying photoresist dry film.

[0035] 2) Exposure and Development: The circuit pattern is transferred to the dry film using an exposure machine, and the copper areas that need to be etched away are exposed after development.

[0036] 3) Etching and Stripping: After cleaning, acidic or alkaline etching solutions are used to etch away the exposed copper, forming precise upper and lower layer circuit patterns, resulting in... Figure 5 The composite board shown has circuit patterns. Finally, the remaining dry film is removed by light-based debonding, and the board is cleaned and transferred to the next process.

[0037] In some optional embodiments, after obtaining the composite board with circuit patterns, ultraviolet laser cutting or high-precision die punching is used to divide the composite board with circuit patterns into independent unit boards 30 with precise outlines, such as... Figure 6 As shown.

[0038] As a further optional implementation, the unit board is stretched and formed according to a preset three-dimensional shape of the product to obtain a three-dimensional flexible circuit structure, which specifically includes: Determine the corresponding hydraulic / pneumatic control timing based on the product's three-dimensional shape; The unit board is placed in a hydraulic / pneumatic forming equipment, and under heating conditions, the unit board is gradually or one-step stretched and formed according to the hydraulic / pneumatic control sequence to obtain a three-dimensional flexible circuit structure.

[0039] Specifically, the unit board is placed in a hydraulic / pneumatic forming machine. Based on the final three-dimensional shape of the product, under heating (temperature below the glass transition temperature of PI) and controlled pressure, the unit board is progressively or in a single-step deep drawing process. This permanently shapes the multilayer insulating clip into the desired non-planar three-dimensional structure, resulting in a three-dimensional flexible circuit structure, such as... Figure 7 As shown. The three-dimensional structure allows the product to adapt more flexibly to complex circuits and meet the requirements of three-dimensional assembly.

[0040] As a further optional implementation, when the electrical contact area and / or functional area are selectively electrolessly silvered or electroplated with silver, the corresponding silver plating thickness is 0.5-5 μm; when the electrical contact area and / or functional area are selectively electrolessly nickeled or electroplated with nickel, the corresponding nickel plating thickness is 1-3 μm.

[0041] Specifically, such as Figure 8As shown, the formed three-dimensional flexible circuit structure undergoes selective chemical silver / nickel plating or electroplating silver / nickel plating in its designated electrical contact area 31 or functional area 32 to ultimately obtain an insulating multilayer Clip. The plating provides excellent conductivity, oxidation resistance, and solderability. Before plating, the target area needs to be cleaned and activated to ensure plating adhesion; after plating, passivation treatment can be performed to further enhance oxidation resistance.

[0042] It is understood that the embodiments of the present invention eliminate the aging and delamination risks of traditional adhesives through the glue-free lamination structure of the multilayer insulating clip, improving the heat resistance, chemical resistance and long-term reliability of the product. At the same time, eliminating the adhesive layer makes the overall product thinner and more flexible. The one-piece molded substrate structure has low internal stress, and combined with the subsequent precise heating and deep drawing process, it can realize complex and stable three-dimensional structures to meet the requirements of more complex three-dimensional circuits. By connecting the deep drawing process with the surface silver / nickel plating process, it not only meets the three-dimensional assembly requirements of the multilayer insulating clip, but also improves the conductivity and contact reliability of the circuit. The single-pressing process avoids multiple alignment errors, with extremely high interlayer alignment accuracy, uniform dielectric layer thickness and good electrical performance consistency. The combination of drilling, etching, laser cutting and other processes with precise temperature control and positioning technology ensures the dimensional accuracy and circuit integrity of the product. The overall manufacturing process is compact, reducing the number of laminations and material usage, and it is more environmentally friendly as it does not use organic adhesives.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] In this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of the present invention. Within the scope of protection of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A multilayer insulating clip for use in power modules, characterized in that, The insulating multilayer Clip includes several copper layers and several TPI modified layers stacked alternately along the thickness direction. The thickness of the copper layers is 100-300 μm, and the thickness of the TPI modified layers is 50-100 μm. The copper layers are used to form circuit signal transmission paths. Adjacent copper layers are bonded together through the TPI modified layers. The TPI modified layers are made of polyimide through material modification treatment.

2. A method for fabricating a multilayer insulating clip for a power module, used to fabricate the multilayer insulating clip for a power module as described in claim 1, characterized in that, Includes the following steps: TPI films are obtained by modifying both sides of polyimide films using one or more methods, including plasma treatment, excimer laser microprocessing, and chemical grafting modification. The copper foil and the TPI film are stacked in a preset alternating stacking pattern to obtain a pre-stacked structure. The pre-stacked structure is then pressed under high temperature, high pressure and vacuum conditions to obtain an integrated composite large board. The integrated composite board is drilled and copper plated to obtain an electroplated composite board; The upper and lower surfaces of the electroplated composite board are respectively coated with dry film, exposed and developed, and etched and stripped to obtain a composite board with circuit patterns. The composite board with circuit patterns is divided into multiple unit boards; The unit board is deep-drawn according to the preset three-dimensional shape of the product to obtain a three-dimensional flexible circuit structure. Selective chemical silver / nickel plating or electroplating silver / nickel plating is performed on the electrical contact area and / or functional area of ​​the three-dimensional flexible circuit structure to obtain the insulating multilayer Clip.

3. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, The material modification treatment is used to roughen the two sides of the polyimide film at the microscopic level, increase the surface area and reactive sites of the two sides of the polyimide film, break the imide rings in the polyimide molecular chains on the two sides of the polyimide film, and introduce reversible crosslinking points to transform the polyimide film into thermoplastic behavior.

4. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, The pressing process is used to cause the TPI film to undergo micro-flow under high temperature and high pressure, thereby enabling the molecular chains of the TPI film to form physical intercalation and chemical bonding with the surface of the copper foil.

5. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, The process of drilling and copper plating the integrated composite board to obtain an electroplated composite board specifically includes: Drill holes at predetermined positions on the integrated composite panel to create multiple through holes penetrating the integrated composite panel; The integrated composite board after drilling is subjected to descaling, activation, and chemical copper plating to form a conductive thin layer. The integrated composite board is electroplated throughout, so that the copper layer on the hole wall of the through hole reaches a preset thickness, thus obtaining the electroplated composite board.

6. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, The process of applying dry film, exposing and developing, and etching and stripping the film onto the upper and lower surfaces of the electroplated composite board to obtain a composite board with circuit patterns specifically includes: The upper and lower surfaces of the electroplated composite plate are coated or covered with a photo-resistant dry film. The preset circuit image is transferred onto the photoresist dry film using an exposure machine, and the copper area that needs to be etched away is exposed after development. The exposed copper areas are etched using an etching solution, and excess photoresist is removed by photo-irradiation to obtain the composite board with circuit patterns.

7. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, The step of deep drawing the unit board according to the preset three-dimensional shape of the product to obtain a three-dimensional flexible circuit structure specifically includes: The corresponding hydraulic / pneumatic control timing is determined based on the three-dimensional shape of the product. The unit board is placed in a hydraulic / pneumatic forming equipment, and under heating conditions, the unit board is gradually or in one step drawn according to the hydraulic / pneumatic control sequence to obtain the three-dimensional flexible circuit structure.

8. The method for fabricating a multilayer insulating clip for a power module according to claim 2, characterized in that, When the electrical contact area and / or functional area are selectively electrolessly silvered or electroplated with silver, the corresponding silver plating thickness is 0.5-5 μm. When the electrical contact area and / or functional area are selectively electrolessly nickeled or electroplated with nickel, the corresponding nickel plating thickness is 1-3 μm.

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