Semiconductor equipment and double-sided silver-coated prefabricated wafer manufacturing process

Abstract

The present application discloses a semiconductor device and a double-sided silver-coated prefabricated sheet manufacturing process thereof, belonging to the field of electronic material preparation. The process comprises preparing a silver paste for sintering; uniformly coating the silver paste on a transfer substrate; drying the silver paste into a silver film; transferring the silver film to the front and back sides of a metal foil to prepare and shape a double-sided silver-coated prefabricated sheet; the double-sided silver-coated prefabricated sheet is used for sintering and welding between a power module and a heat sink. In other words, the double-sided silver-coated prefabricated sheet obtained by the double-sided silver-coated prefabricated sheet manufacturing process of the present application has a uniform thickness. Under the premise of ensuring the normal heat dissipation requirements after welding, the defects of the original welding silver paste are reduced, thereby improving the welding reliability, and further ensuring the stability of the heat dissipation performance when the double-sided silver-coated prefabricated sheet is used as a welding sheet between a heat sink and a power module.

Description

Technical Field

[0001] The present application relates to the field of electronic material preparation, and in particular to a semiconductor device and a process for manufacturing a double-sided silver-coated prefabricated sheet thereof. Background Art

[0002] With the rapid development of electronic technology, the application of semiconductor devices has become more and more extensive. However, due to the characteristics of semiconductor devices, a large amount of heat is generated when they are used. If the heat dissipation of semiconductor devices is not timely, their working efficiency and service life will be affected.

[0003] In order to solve the heat dissipation problem of semiconductor devices, sintered silver technology is used to coat silver paste between the semiconductor device and the substrate, which is usually a DBC (Direct Bonding Copper) substrate or an AMB substrate (Active Metal Brazing), so as to package it into a power module, and coat silver paste between the power module and the radiator, and sinter and fix them by brazing.

[0004] However, in this process, the large soldering area between the power module and the heat sink often results in a certain amount of deformation in the substrate. Therefore, when using silver paste for sintering and soldering, a very thick layer of silver paste must be printed to ensure a reliable soldering connection. However, when the silver paste is printed thickly, the organic solvent in the paste is difficult to evaporate completely, which can easily cause defects such as voids and uneven density during the sintering process, thus preventing the thermal conductivity from reaching the expected high level. Summary of the Invention

[0005] In view of this, the main purpose of this application is to provide a semiconductor device and a double-sided silver-coated prefabricated sheet manufacturing process thereof, aiming to improve the stability of the thermal conductivity of the sintered silver paste.

[0006] To achieve the above objectives, the present application provides a semiconductor device, including a power module, a double-sided silver-coated preform, and a heat sink:

[0007] The power module is used to perform the corresponding functions of the semiconductor devices in the power module;

[0008] The radiator is used to dissipate heat from the power module;

[0009] The double-sided silver-coated prefabricated sheet is used to weld and fix the power module to the heat sink.

[0010] Optionally, the radiator is provided at the lower end of the power module, the double-sided silver-clad prefabricated sheet is connected between the power module and the radiator, and the double-sided silver-clad prefabricated sheet fixes the power module and the radiator by sintering and welding;

[0011] The power module is encapsulated by coating silver paste between the semiconductor device and the ceramic copper-clad plate, and the double-sided silver-coated prefabricated sheet is obtained by coating silver paste of uniform thickness on both sides of a metal foil made of ferrous metal or non-ferrous metal.

[0012] To achieve the above objectives, the present application provides a process for manufacturing a double-sided silver-coated prefabricated sheet, comprising the following steps:

[0013] preparing silver paste for sintering;

[0014] Evenly coating the silver paste on a transfer substrate;

[0015] drying the silver paste to form a silver film;

[0016] The silver film is transferred to the front and back sides of the metal foil to prepare and shape it to obtain a double-sided silver-coated prefabricated sheet; the double-sided silver-coated prefabricated sheet is used for sintering and welding between the power module and the heat sink.

[0017] Optionally, after transferring the silver film to both sides of the metal foil to prepare and shape a double-sided silver-coated prefabricated sheet, the process further includes:

[0018] Transfer the silver film of a preset silver-covered area to both sides of the metal foil;

[0019] Determining the area to be cut of the double-sided silver-coated prefabricated sheet;

[0020] The double-sided silver-coated prefabricated sheet is processed and cut according to the area to be cut, and the cut double-sided silver-coated prefabricated sheet is packaged; wherein, a wafer carrier or a feeder belt is used for packaging.

[0021] Optionally, the step of uniformly coating the silver paste on the transfer substrate comprises:

[0022] Select high temperature resistant film material as transfer substrate;

[0023] Silver paste with a thickness of 20 μm to 200 μm is evenly coated on the transfer substrate.

[0024] Optionally, drying the silver paste to form a silver film includes:

[0025] When drying the silver paste to form a silver film, the silver paste is dried at a heating temperature of 100° C. to 200° C. until solidified and formed.

[0026] Optionally, before transferring the silver film to the front and back sides of the metal foil, the process includes:

[0027] Select a metal foil with a thickness of 20um to 500um; wherein the material selection range of the metal foil includes ferrous metals and non-ferrous metals;

[0028] The surface of the metal foil is plated; wherein, the front and back sides of the plated metal foil are to be covered with a silver film; wherein, the selection range of the plating material includes gold, silver, nickel / gold, nickel / palladium / gold, and nickel / silver.

[0029] Optionally, the silver film is transferred to both sides of the metal foil to prepare a double-sided silver-coated prefabricated sheet, comprising:

[0030] After transferring the silver film to both the front and back sides of the metal foil, heating and pressurizing the combination of the silver film and the metal foil;

[0031] After the composition is prepared and formed, a double-sided silver-coated prefabricated sheet is obtained.

[0032] Optionally, the heating and pressurizing treatment of the combination of the silver film and the metal foil comprises:

[0033] placing the combination of the silver film and the metal foil in a vacuum state, and subjecting the combination to heating and pressurizing treatment;

[0034] Alternatively, the combination of the silver film and the metal foil is placed under an inert gas protection state, and the combination is subjected to heating and pressurization treatment;

[0035] The temperature required for the heating and pressurizing treatment is 100° C. to 200° C., and the pressure required is 3 to 10 MPa.

[0036] Optionally, the preparation and shaping of the composition to obtain a double-sided silver-coated prefabricated sheet comprises:

[0037] After the composition is subjected to the heating and pressurizing treatment, a double-sided silver-coated prefabricated sheet is prepared; wherein the structural system of the silver layer of the double-sided silver-coated prefabricated sheet includes a nanometer, micrometer and micro-nano hybrid system.

[0038] Compared with the prior art method of coating silver paste between the power module and the heat sink and sintering and fixing them by brazing, when the silver paste is thick, the organic solvent in the silver paste is difficult to evaporate completely, which easily causes defects such as voids and uneven density during the sintering process, thereby preventing the thermal conductivity from reaching a normal high level. In the present application, a silver paste for sintering is prepared and evenly coated on a transfer substrate. On the transfer substrate, the silver paste is dried into a silver film, and the silver film is transferred to the front and back sides of a metal foil to prepare and shape a double-sided silver-coated prefabricated sheet. By using this double-sided silver-coated prefabricated sheet, it is placed between the power module and the heat sink and used for sintering and welding. That is, the thick silver paste originally used for sintering and fixing is replaced with a double-sided silver-coated prefabricated sheet of uniform thickness, avoiding the problem of defects in the silver paste caused by the influence of organic solvents, thereby improving the welding density, and then keeping the thermal conductivity of the welding layer stable, thereby ensuring the stability and reliability of heat exchange between the power module and the heat sink. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0041] Figure 1 This is a schematic flow chart of a first embodiment of a process for manufacturing a double-sided silver-coated prefabricated sheet of the present application;

[0042] Figure 2 This is a schematic diagram of the structure of traditional sintered silver paste welding power module and heat sink;

[0043] Figure 3 This is a schematic diagram of the structure of a double-sided silver-coated prefabricated sheet;

[0044] Figure 4 This is a schematic diagram of the structure of the double-sided silver-coated prefabricated sheet when in use.

[0045] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0047] The present invention provides a semiconductor device including a power module, a double-sided silver-coated prefabricated sheet, and a heat sink.

[0048] The power module is used to perform the corresponding functions of the semiconductor devices in the power module;

[0049] The radiator is used to dissipate heat from the power module;

[0050] The double-sided silver-coated prefabricated sheet is used to weld and fix the power module to the heat sink.

[0051] Optionally, the radiator is provided at the lower end of the power module, the double-sided silver-clad prefabricated sheet is connected between the power module and the radiator, and the double-sided silver-clad prefabricated sheet fixes the power module and the radiator by sintering and welding;

[0052] The power module is encapsulated by coating silver paste between the semiconductor device and the ceramic copper-clad plate, and the double-sided silver-coated prefabricated sheet is obtained by coating silver paste of uniform thickness on both sides of a metal foil made of ferrous metal or non-ferrous metal.

[0053] The present invention provides a method for manufacturing a double-sided silver-coated prefabricated sheet. Figure 1 , Figure 1 This is a flow chart of the first embodiment of the process for manufacturing a double-sided silver-coated prefabricated sheet of the present application.

[0054] In this embodiment, the process for manufacturing the double-sided silver-coated prefabricated sheet includes:

[0055] Step S110: preparing silver paste for sintering;

[0056] In this embodiment, a silver paste is prepared for sintering. The sintering process is to sinter and fix the power module and the heat sink, apply the silver paste between the power module and the heat sink, and sinter the silver paste layer to convert it into a solder layer.

[0057] Among them, the power module is obtained by encapsulating semiconductor devices with silver paste.

[0058] Reference Figure 2 , Figure 2 This is a schematic diagram of the structure of traditional sintered silver paste welding power module and heat sink. Figure 2 The middle chip is a general semiconductor device. A DBC substrate is provided at the lower end of the chip. The substrate and the chip are coated with silver paste (that is, the power module is obtained by silver paste packaging, including the chip, silver paste, and DBC substrate, wherein the DBC substrate can be replaced with an AMB substrate). A heat sink is provided at the lower section of the power module, and silver paste is coated between the heat sink and the power module. The silver paste is brazed to connect the heat sink and the power module, but there is a problem of unstable thermal conductivity.

[0059] Step S120: evenly coating the silver paste on the transfer substrate;

[0060] The process of evenly coating the silver paste on the transfer substrate is mainly used to prepare the silver film. Among them, uniform coating is the key to avoid uneven thickness and excessive thickness of the silver paste, thereby avoiding the influence of the thickness of the silver paste on the thermal conductivity after welding.

[0061] In this embodiment, when the silver paste is coated on the transfer substrate, the thickness of the coated silver paste is controlled by using automated equipment, wherein the automated equipment includes but is not limited to coating equipment, printing equipment, etc.

[0062] Taking the coating equipment as an example, the larger the coating gap, the thicker the silver paste coated on the transfer substrate; the slower the coating speed, the thicker the silver paste coated on the transfer substrate; when the silver paste used has high viscosity and high solid content, the thicker the silver paste coated on the transfer substrate; conversely, the thickness of the silver paste coated on the transfer substrate is thinner.

[0063] In this embodiment, automated equipment is used to ensure that the thickness of the silver paste coated on the transfer substrate is uniform and thin. When other automated equipment is used, it is similar to the above content, but different equipment has different debugging methods, which will not be repeated here.

[0064] Optionally, the step of uniformly coating the silver paste on the transfer substrate comprises:

[0065] Select high temperature resistant film material as transfer substrate;

[0066] Before applying the silver paste to the transfer substrate, a suitable material must be selected as the transfer substrate. When preparing the silver film, the silver paste needs to be heated and dried, so the transfer substrate needs to be a high-temperature resistant material.

[0067] In this embodiment, a high-temperature resistant film material is selected as the transfer substrate. For example, the high-temperature resistant film material includes but is not limited to PET film (Polyester Film).

[0068] Silver paste with a thickness of 20 μm to 200 μm is evenly coated on the transfer substrate.

[0069] In order to avoid directly applying a thick layer of silver paste between the power module and the heat sink, two parameters of the silver paste need to be controlled when applying the silver paste on the transfer substrate: the flatness (uniformity) parameter and the thickness parameter. When using automated equipment for coating, the flatness parameter of the coated silver paste needs to be controlled. At this time, the thickness of the silver paste needs to be further controlled.

[0070] In this embodiment, the thickness of the silver paste coated on the transfer substrate is controlled within a range of 20 um to 200 um, wherein the thickness of the silver paste includes two parameters: 20 um and 200 um.

[0071] Step S130: drying the silver paste to form a silver film;

[0072] After the silver paste is coated on the transfer substrate, the silver paste is heated and dried to fix the shape of the silver paste (parameters such as area and thickness, including the flatness of the silver paste). The dried silver paste forms a silver film.

[0073] In this embodiment, the prepared silver film is the raw material for the subsequent preparation of a double-sided silver-coated prefabricated sheet. The process of preparing the silver film is a continuous production process. Every time two silver films of the same size are prepared, they can be used to prepare a double-sided silver-coated prefabricated sheet of the same size as the silver film.

[0074] Optionally, drying the silver paste to form a silver film includes:

[0075] When drying the silver paste to form a silver film, the silver paste is dried at a heating temperature of 100° C. to 200° C. until solidified and formed.

[0076] In this embodiment, the silver paste used is a sintered silver paste, which is essentially a nanometer or micrometer-level fine structure. When heating the silver paste, it only needs to be heated at a temperature of 100°C to 200°C to achieve the effect of solidifying it into shape.

[0077] Step S140: transferring the silver film to both sides of the metal foil to prepare and shape a double-sided silver-coated prefabricated sheet; the double-sided silver-coated prefabricated sheet is used for sintering and welding between the power module and the heat sink.

[0078] The traditional power module and the heat sink are fixed by coating a certain thickness of silver paste and brazing them. The heat sink then transfers the heat from the power module to the heat sink through the welding layer.

[0079] In this embodiment, a double-sided silver-coated prefabricated sheet is used instead of the silver paste layer used in the welding layer. In order to ensure that the prefabricated sheet can be used, the heat sink and the power module are fixed by welding or sintering. Therefore, both the front and back sides of the prefabricated sheet need to be covered with silver film, so that the middle of the prefabricated sheet is a metal foil. The front side of the prefabricated sheet is connected to either the power module or the heat sink, and the back side of the prefabricated sheet is connected to the other power module or the heat sink. The heat sink, the double-sided silver-coated prefabricated sheet and the power module are fixedly connected by the silver film.

[0080] Therefore, silver films are attached to both sides of the metal foil, and the silver films are attached to the metal foil by transfer printing. The metal foil and the silver films on both sides of the metal foil are integrally prepared to obtain a double-sided silver-coated prefabricated sheet.

[0081] Reference Figure 3 , Figure 3 It is a schematic diagram of the structure of the double-sided silver-coated prefabricated sheet. Figure 3 In the figure, the double-sided silver-clad preform is divided into a three-layer structure. From top to bottom, the first and third layers are silver films, and the second layer in the middle is metal foil. The double-sided silver-clad preform with this structural feature is to divide the original thicker layer of sintered silver into two parts and prepare them on both sides of the metal foil, so that the organic component of the silver film to be sintered is less, the film layer is uniform and has a certain density, and the overall thickness of the prefabricated solder sheet also meets the requirements of sintering the power module and the heat sink.

[0082] Optionally, before transferring the silver film to the front and back sides of the metal foil, the process includes:

[0083] Select a metal foil with a thickness of 20um to 500um; wherein the material selection range of the metal foil includes ferrous metals and non-ferrous metals;

[0084] Before making a double-sided silver-coated preform, it is necessary to select the material of the metal foil in the middle of the preform. The metal foil serves as the substrate for the two layers of silver film. The material selection range of the metal foil includes ferrous metals and non-ferrous metals, including pure metals such as gold, silver, copper, aluminum, and molybdenum. Alloy materials such as stainless steel and Invar36 (a special low-expansion iron-nickel alloy with an ultra-low expansion coefficient) can also be used.

[0085] In order to prevent the thickness of the double-sided silver-coated prefabricated sheet from being too large, the thickness of the metal foil is selected to be 20um to 500um, and the thickness includes parameters at both ends of the range.

[0086] The surface of the metal foil is plated; wherein, the front and back sides of the plated metal foil are to be covered with a silver film; wherein, the selection range of the plating material includes gold, silver, nickel / gold, nickel / palladium / gold, and nickel / silver.

[0087] Optionally, the silver film is transferred to both sides of the metal foil to prepare a double-sided silver-coated prefabricated sheet, comprising:

[0088] After transferring the silver film to both the front and back sides of the metal foil, heating and pressurizing the combination of the silver film and the metal foil;

[0089] After the composition is prepared and formed, a double-sided silver-coated prefabricated sheet is obtained.

[0090] After the silver film is transferred to the front and back sides of the metal foil, the combination of the silver film and the metal foil needs to be heated and pressurized to prepare a double-sided silver-coated prefabricated sheet.

[0091] In this embodiment, the silver film is obtained by drying the silver paste. When preparing the double-sided silver-coated prefabricated sheet, the combination of the silver film and the metal foil is heated and pressurized, so that the silver film and the metal foil form an integral fixed structure.

[0092] Optionally, the heating and pressurizing treatment of the combination of the silver film and the metal foil comprises:

[0093] placing the combination of the silver film and the metal foil in a vacuum state, and subjecting the combination to heating and pressurizing treatment;

[0094] Alternatively, the combination of the silver film and the metal foil is placed under an inert gas protection state, and the combination is subjected to heating and pressurization treatment;

[0095] The temperature required for the heating and pressurizing treatment is 100° C. to 200° C., and the pressure required is 3 to 10 MPa.

[0096] In this embodiment, the composition of metal foil and silver film is heated and pressurized to obtain a double-sided silver-coated preformed sheet. The required temperature for heating and pressurizing treatment is 100°C to 200°C and the required pressure is 3 to 10 MPa.

[0097] In addition, when the composition is subjected to heating and pressurizing treatment, the composition needs to be placed in a special environment to ensure that the composition can be stably formed during the heating and pressurizing process.

[0098] In this embodiment, the composition needs to be placed in a vacuum state or under an inert gas protection state, and the composition needs to be heated and pressurized.

[0099] Optionally, the preparation and shaping of the composition to obtain a double-sided silver-coated prefabricated sheet comprises:

[0100] After the composition is subjected to the heating and pressurizing treatment, a double-sided silver-coated prefabricated sheet is prepared; wherein the structural system of the silver layer of the double-sided silver-coated prefabricated sheet includes a nanometer, micrometer and micro-nano hybrid system.

[0101] In this embodiment, the silver paste used is used as a welding material for the intermediate connection between the power module and the heat sink, that is, a sintered material. The structure of the sintered silver paste is a nanometer, micrometer, or micro-nano mixed structure. The characteristic of this structure is that the silver paste can be transformed from a fluid state to a fixed crystal at medium or high temperature. Therefore, when heating the silver paste, there is no need to use excessively high temperatures. That is, 100°C to 200°C is sufficient to complete the preparation process of the double-sided silver-coated prefabricated sheet.

[0102] Reference Figure 4 , Figure 4 This is a schematic diagram of the structure of the double-sided silver-coated prefabricated sheet when in use. Figure 4 The upper layer is the power module, the lower layer is the heat sink, and a double-sided silver-clad preform is placed between the power module and the heat sink. Using this double-sided silver-clad preform for sintering and welding the power module and heat sink together ensures welding reliability due to its structural characteristics (thickness, uniformity, density, etc.). It also significantly reduces defects in the weld layer and effectively increases weld density, thereby ensuring a stable and high thermal conductivity of the weld layer.

[0103] Optionally, after transferring the silver film to both sides of the metal foil to prepare and shape a double-sided silver-coated prefabricated sheet, the process further includes:

[0104] The silver film with a preset silver-covered area is transferred to the front and back sides of the metal foil.

[0105] At the same time, the area of ​​the end of the power module to be cooled is used to determine the area of ​​the bonding area between the power module and the heat sink, which affects the area required for the double-sided silver-coated prefabricated sheet.

[0106] In order to ensure that the prefabricated sheet can perfectly fit the end of the power module to be cooled, the area of ​​the prefabricated sheet is larger than the end of the power module to be cooled.

[0107] The preset silver coating area is a range of silver coating that is a preset percentage larger than the area of ​​the power module's heat dissipation end. Based on this silver coating area, the area transferred to the front and back surfaces of the metal foil is determined. This preset ratio can be 5% or 10%, and can be adjusted based on actual conditions.

[0108] Therefore, if the area of ​​the end to be cooled of the power module is 10 and the preset ratio is 10%, then the preset silver-coated area is determined to be 11.

[0109] Determining the area to be cut of the double-sided silver-coated prefabricated sheet;

[0110] In this embodiment, the area to be cut is calculated for power modules of different sizes and the area of ​​the end to be dissipated of the power module, so that the prepared double-sided silver-coated prefabricated sheet can better fit the power module.

[0111] The double-sided silver-coated prefabricated sheet is processed and cut according to the area to be cut, and the cut double-sided silver-coated prefabricated sheet is packaged; wherein, a wafer carrier or a feeder belt is used for packaging.

[0112] The double-sided silver-coated prefabricated sheets are processed and cut according to the area to be cut, and after the cutting is completed, the cut and shaped double-sided silver-coated prefabricated sheets (with different areas) are packaged. The packaging process includes automatic packaging and manual packaging. At the same time, wafer carriers or feeder belts are used for packaging. The packaging process includes but is not limited to the above two general methods of packaging electronic materials.

[0113] In addition, the packaging method also includes using a packaging box, which is a chip storage box, a chip storage tray or a waffle box. Such a box has a plurality of fixed squares for placing chips, and the size of the squares is determined according to the size required for actual use.

[0114] In this embodiment, the area of ​​the double-sided silver-coated prefabricated sheet is close to the size of the chip (power module), and this type of box can be used to store the double-sided silver-coated prefabricated sheet.

[0115] Compared with the prior art method of coating silver paste between the power module and the heat sink and sintering and fixing them by brazing, when the silver paste is thick, the organic solvent in the silver paste is difficult to evaporate completely, which easily causes defects such as voids and uneven density during the sintering process, thereby preventing the thermal conductivity from reaching a normal high level. In the present application, a silver paste for sintering is prepared and evenly coated on a transfer substrate. On the transfer substrate, the silver paste is dried into a silver film, and the silver film is transferred to the front and back sides of a metal foil to prepare and shape a double-sided silver-coated prefabricated sheet. By using this double-sided silver-coated prefabricated sheet, it is placed between the power module and the heat sink and used for sintering and welding. That is, the thick silver paste originally used for sintering and fixing is replaced with a double-sided silver-coated prefabricated sheet of uniform thickness, avoiding the problem of defects in the silver paste caused by the influence of organic solvents, thereby improving the welding density, and then keeping the thermal conductivity of the welding layer stable, thereby ensuring the stability and reliability of heat exchange between the power module and the heat sink.

[0116] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, technique, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, technique, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, technique, article, or system comprising the element.

[0117] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0118] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A semiconductor device, characterized in that: The semiconductor device includes a power module, a double-sided silver-coated prefabricated sheet and a heat sink: The power module is used to perform the corresponding functions of the semiconductor devices in the power module; The radiator is provided at the lower end of the power module, and the double-sided silver-coated prefabricated sheet is connected between the power module and the radiator, and the double-sided silver-coated prefabricated sheet fixes the power module and the radiator by sintering and welding; The power module is encapsulated by coating silver paste between the semiconductor device and the ceramic copper-clad laminate, and the double-sided silver-coated prefabricated sheet is obtained by coating silver paste of uniform thickness on both sides of a metal foil made of ferrous metal or non-ferrous metal; The surface of the metal foil is subjected to a coating treatment; wherein the front and back sides of the coated metal foil are to be covered with a silver film; wherein the coating material is selected from the range of gold, nickel / gold, nickel / palladium / gold, and nickel / silver; The radiator is used to dissipate heat from the power module; The double-sided silver-coated prefabricated sheet is used to weld and fix the power module to the heat sink.

2. A process for preparing a semiconductor device according to claim 1, characterized in that: The manufacturing process of the semiconductor device comprises the following steps: preparing silver paste for sintering; Evenly coating the silver paste on a transfer substrate; drying the silver paste to form a silver film; The silver film is transferred to the front and back sides of the metal foil to prepare and shape it to obtain a double-sided silver-coated prefabricated sheet; the double-sided silver-coated prefabricated sheet is used for sintering and welding between the power module and the heat sink.

3. The process for preparing a semiconductor device according to claim 2, wherein: After transferring the silver film to the front and back sides of the metal foil to prepare and shape a double-sided silver-coated prefabricated sheet, the method further includes: Transfer the silver film of a preset silver-covered area to both sides of the metal foil; Determining the area to be cut of the double-sided silver-coated prefabricated sheet; The double-sided silver-coated prefabricated sheet is processed and cut according to the area to be cut, and the cut double-sided silver-coated prefabricated sheet is packaged; wherein, a wafer carrier or a feeder belt is used for packaging.

4. The process for preparing a semiconductor device according to claim 3, wherein: The step of uniformly coating the silver paste on the transfer substrate comprises: Select high temperature resistant film material as transfer substrate; Silver paste with a thickness of 20 μm to 200 μm is evenly coated on the transfer substrate.

5. The process for preparing a semiconductor device according to claim 3, wherein: The step of drying the silver paste to form a silver film comprises: When drying the silver paste to form a silver film, the silver paste is dried at a heating temperature of 100° C. to 200° C. until solidified.

6. The process for preparing a semiconductor device according to claim 2, wherein: Before transferring the silver film to the front and back sides of the metal foil, the method includes: Select a metal foil with a thickness of 20um to 500um; wherein the material selection range of the metal foil includes ferrous metals and non-ferrous metals; The surface of the metal foil is subjected to a coating treatment; wherein, the front and back sides of the coated metal foil are to be covered with a silver film; wherein, the selection range of the coating material includes gold, nickel / gold, nickel / palladium / gold, and nickel / silver.

7. The process for preparing a semiconductor device according to claim 6, wherein: The silver film is transferred to the front and back sides of the metal foil to prepare a double-sided silver-coated prefabricated sheet, comprising: After transferring the silver film to both the front and back sides of the metal foil, heating and pressurizing the combination of the silver film and the metal foil; After the composition is prepared and formed, a double-sided silver-coated prefabricated sheet is obtained.

8. The process for preparing a semiconductor device according to claim 7, wherein: The heating and pressurizing treatment of the combination of the silver film and the metal foil comprises: placing the combination of the silver film and the metal foil in a vacuum state, and subjecting the combination to heating and pressurizing treatment; Alternatively, the combination of the silver film and the metal foil is placed under an inert gas protection state, and the combination is subjected to heating and pressurization treatment; The temperature required for the heating and pressurizing treatment is 100° C. to 200° C., and the pressure required is 3 to 10 MPa.

9. The process for preparing a semiconductor device according to claim 7, wherein: The process of preparing the composition to form a double-sided silver-coated prefabricated sheet comprises: After the composition is subjected to the heating and pressurizing treatment, a double-sided silver-coated prefabricated sheet is prepared; wherein the structural system of the silver layer of the double-sided silver-coated prefabricated sheet includes a nanometer, micrometer and micro-nano hybrid system.

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