Preparation method of test sample suitable for reliability test and test sample

Abstract

The invention relates to a test sample preparation method suitable for reliability test and a test sample, and the method comprises the steps: providing a power device chip to be subjected to reliability test, and assembling the power device chip on a DBC board to form a power chip assembly; assembling the formed power chip assembly on a radiator so as to utilize the radiator to radiate heat of the power chip assembly, preparing an insulation isolation protection layer in the assembly fixing piece, and enabling the insulation isolation protection layer to cover the power chip assembly, and the insulation isolation protection layer is used for carrying out insulation isolation protection on the power chip assembly. According to the method, the reliability test cost can be saved, the product and process reliability evaluation period is shortened, and the product development or process verification efficiency is improved.

Description

Technical Field

[0001] The invention relates to a test sample preparation method and the test sample, in particular to a test sample preparation method and the test sample suitable for reliability testing. Background Art

[0002] Reliability testing is an essential part of power device product development and process verification. It is an effective means of evaluating power device design and manufacturing processes. It is also the most effective way to evaluate the performance and life of power device chips.

[0003] When evaluating the reliability of power device chip products or manufacturing processes, the first step is chip production, then chip packaging, and finally chip on-machine assessment, such as HTRB (High Temperature Reverse Bias) or HTGB (High Temperature Gate Bias) reliability tests.

[0004] As is well known to those skilled in the art, sending power devices to packaging factories for packaging is expensive and slow. The general packaging process is as follows: the chip manufacturer finds a suitable packaging factory for packaging, the chip manufacturer places an engineering order with the packaging factory, and the packaging factory arranges production. The entire process takes at least one week, and at most one or two months. If the packaging factory needs to customize a new mold or has tight production capacity, the entire process may take several months. Therefore, the chip packaging process is too long for chip design and development, which will lengthen the entire development cycle and reduce development efficiency.

[0005] On the other hand, most packaging manufacturers currently charge engineering fees and material packaging fees, resulting in each batch of packaging process requiring several thousand yuan in packaging fees. If reliability tests are required for multiple batches of multiple products, the entire testing process will require a large amount of packaging fees.

[0006] Therefore, how to quickly and cost-effectively test power devices is a technical problem that urgently needs to be solved. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a test sample preparation method and a test sample suitable for reliability testing, which can save the cost of reliability testing, shorten the product and process reliability evaluation cycle, and improve the efficiency of product development or process verification.

[0008] According to the technical solution provided by the present invention, a test sample preparation method suitable for reliability testing comprises: Providing a power device chip to be tested for reliability, and assembling the power device chip onto a DBC board to form a power chip assembly; The power chip assembly formed as above is assembled onto a heat sink, so as to utilize the heat sink to dissipate heat from the power chip assembly, wherein: When performing reliability testing on a power device chip, after heat dissipation by a heat sink, at least the test temperature of the power device chip is adapted to the target test junction temperature; When the power chip assembly is assembled on the heat sink, the power chip assembly is fixed on the heat sink by using the assembly fixing member, wherein after the power chip assembly is fixed on the heat sink by using the assembly fixing member, at least the power device chip of the power chip assembly is in an exposed state; An insulating isolation protection layer is prepared in the component fixture, and the insulating isolation protection layer is covered on the power chip component, so as to utilize the insulating isolation protection layer to perform insulating isolation protection on the power chip component.

[0009] When assembling the power device chip onto the DBC board and forming a power chip assembly, it includes: A DBC board adapted to a power device chip is provided, wherein the DBC board comprises a supporting substrate and a chip terminal connector adapted to the power device chip, and the chip terminal connector is arranged on the supporting substrate; Place the power device chip on the DBC board, and make the corresponding end pins of the power device chip fit and connect with the corresponding chip terminal connector on the DBC board; At least one connection terminal is welded on each chip terminal connection body of the DBC board, and the connection terminal is electrically connected to the welded chip terminal connection body.

[0010] The power device chip is welded on a chip terminal connector of the DBC board so that one end pin of the power device chip is electrically connected to the welded chip terminal connector, and then the remaining end pins of the power device chip are wire-bonded to the corresponding chip terminal connector, wherein: During wire bonding, the bonding wires used include aluminum wires, copper wires or copper ribbons.

[0011] The shape of the terminal block includes column or strip, wherein: All the wiring terminals are parallel to each other and all the wiring terminals are located on the same side of the DBC board.

[0012] When assembling the power chip assembly onto the heat sink, first apply thermal grease on the connection surface of the heat sink to form a thermal grease layer on the connection surface of the heat sink, wherein the area of ​​the thermal grease layer is not less than the area of ​​the DBC board; The back side of the DBC board in the power chip assembly is placed on the thermal grease layer, and then the power chip assembly is fixed on the heat sink using an assembly fixing piece.

[0013] The central area of ​​the component fixture is provided with a fixture through hole adapted to the power chip component, and the back of the component fixture is provided with a fixed alignment groove adapted to the DBC board, wherein: When the power chip assembly is fixed by the assembly fixing piece, the assembly fixing piece is aligned with the DB board by the fixing alignment groove and covers the heat sink, and the assembly fixing piece is fixed to the connection surface of the heat sink by the fixing connecting piece, wherein when the assembly fixing piece is pressed on the heat sink, the power device chip on the DBC board is exposed through the fixing piece through hole.

[0014] A plurality of heat dissipation components are arranged on the heat dissipation surface of the heat sink, wherein the heat dissipation components include heat dissipation fins; The method of fixing the component fixing part on the heat sink by using the fixing connecting part includes bolt connection, and the component fixing part is insulated from the power chip component and the heat sink.

[0015] When preparing the insulating isolation protective layer, it includes: An insulating isolation protection material is provided and injected into the fixing member through hole to form an insulating isolation protection layer after the insulating isolation protection material is solidified, and the insulating isolation protection layer is completely located in the fixing member through hole.

[0016] The insulating isolation protection material is at least silica gel; the temperature that the component fixing part can withstand is higher than the reliability temperature of the power device chip.

[0017] A test sample suitable for reliability testing, wherein the test sample is prepared by the preparation method.

[0018] The advantages of the present invention are as follows: the power device chip is assembled on the DBC board to form a power chip assembly, the power chip assembly is assembled on the radiator, and is fixed on the connecting surface of the radiator by means of an assembly fixing part, and thereafter, the power chip assembly is insulated and protected by means of an insulating isolation protection layer, thereby achieving rapid packaging of the power device chip, shortening the product packaging time, thereby accelerating the product reliability evaluation cycle, and reducing the reliability testing process cost.

[0019] When preparing the test samples, the materials and equipment used are easy to obtain and the cost is low; the heat sink is used to dissipate the heat of the power chip assembly to ensure that the temperature of the power device chip during the reliability test is adapted to the target test junction temperature, so as to ensure that the temperature of the actual power device chip is as close as possible to the set target test junction temperature. Through the heat dissipation of the heat sink, the heat generated by the self-heating of the power device chip during the reliability test can be quickly and effectively discharged, rather than accumulated inside the power device chip to increase the temperature of the power device chip, thereby avoiding the temperature of the power device chip being significantly higher than the set target test junction temperature, and even generating a positive feedback loop, so that the temperature continues to rise and then damages the power device chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of an embodiment of test sample preparation of the present invention.

[0021] Figure 2 A schematic diagram of an embodiment of the test sample of the present invention.

[0022] Figure 3 It is a schematic diagram of an embodiment of the present invention after the fixed connecting piece on the test sample is removed.

[0023] Figure 4 It is a schematic diagram of an embodiment of the present invention after the component fixing piece on the test sample is removed.

[0024] Figure 5 For the general Figure 4 A schematic diagram of an embodiment after the insulating isolation protection layer is removed.

[0025] Figure 6 It is a schematic diagram of an embodiment of the component fixing part of the present invention.

[0026] Explanation of the accompanying drawings: 1-heat sink, 2-component fixing part, 3-insulating isolation protective layer, 4-connecting terminal, 5-fixed connecting part, 6-fixed part connecting hole, 7-heat sink fin, 8-heat sink connecting hole, 9-power chip component, 10-DBC board, 11-power device chip, 12-first chip terminal connector, 13-second chip terminal connector, 14-third chip terminal connector, 15-first bonding wire, 16-second bonding wire, 17-fixed alignment groove, 18-fixed positioning groove, 19-fixed part through hole, 20-connection surface. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0028] In order to save the cost of reliability testing, shorten the product and process reliability evaluation cycle, and improve the efficiency of product development or process verification, the present invention provides a test sample preparation method suitable for reliability testing. Specifically, the test sample preparation method includes: Providing a power device chip 11 to be tested for reliability, and assembling the power device chip 11 onto a DBC board to form a power chip assembly 9; The power chip assembly 9 formed as above is assembled onto the heat sink 1, so as to utilize the heat sink 1 to dissipate heat from the power chip assembly 9, wherein: When the reliability test is performed on the power device chip 11, after the heat is dissipated by the heat sink 1, at least the test temperature of the power device chip 11 is adapted to the target test junction temperature; When the power chip assembly 9 is assembled on the heat sink 1, the power chip assembly 9 is fixed on the heat sink 1 by the assembly fixing member 2, wherein after the power chip assembly 9 is fixed on the heat sink 1 by the assembly fixing member 2, at least the power device chip 11 of the power chip assembly 9 is in an exposed state; An insulating isolation protection layer 3 is prepared in the component fixture 2 , and the insulating isolation protection layer 3 is covered on the power chip component 9 , so that the insulating isolation protection layer 3 is used to perform insulating isolation protection on the power chip component 9 .

[0029] Figure 1 , an embodiment of a method for preparing a test sample is shown in the figure. As can be seen from the figure, when preparing the test sample, at least a power device chip 11 is provided, wherein the power device chip 11 is a chip to be subjected to a reliability test, and the reliability test to be conducted may include the above-mentioned HTRB test and / or HTGB test. The type of reliability test conducted on the power device chip 11 can be selected as required, and will not be described in detail here. It can be understood that the prepared test sample is to prepare the power device chip 11 to be subjected to a reliability test into a sample that is convenient for reliability testing.

[0030] In order to be suitable for reliability testing, the power device chip 11 should be assembled on a DBC (Direct Bond Copper) board, wherein after the power device chip 11 is assembled on the DBC board, a power chip assembly 9 can be formed. The following is an example of the method and process of forming the power chip assembly 9.

[0031] In one embodiment of the present invention, when assembling the power device chip 11 onto the DBC board to form the power chip assembly 9, the process includes: A DBC board adapted to a power device chip 11 is provided, wherein the DBC board comprises a support substrate 10 and a plurality of chip terminal connectors adapted to the power device chip 11, wherein the chip terminal connectors are arranged on the support substrate 10; Place the power device chip 11 on the DBC board, and make the corresponding end pins of the power device chip 11 fit and connect with the corresponding chip terminal connector on the DBC board; At least one connection terminal 4 is welded on each chip terminal connection body of the DBC board, and the connection terminal 4 is electrically connected to the welded chip terminal connection body.

[0032] It is understandable that the DBC board should be related to the type of the power tube device chip 11, wherein the type of the power device chip 11 can be an IGBT chip, or a VDMOS chip, a diode or other power device, and the type of the power device chip 11 can be selected as needed to meet the requirements of reliability testing. It should be noted that the DBC board is adapted to the power device chip 11, specifically, it can be connected to the corresponding pins of the power device chip 11, so as to conduct subsequent reliability testing.

[0033] Figure 5 , an embodiment of a power chip assembly 9 and a DBC board is shown in the figure, in which the DBC board may include a support substrate 10 and a plurality of chip terminal connectors, wherein the support substrate 10 may be made of ceramic materials such as aluminum oxide or aluminum nitride, or materials such as silicon carbide, the support substrate 10 does not have a conductive ability, but the chip terminal connector should have a conductive ability, that is, the chip terminal connector should be made of a metal material, and the chip terminal connectors are independent of each other on the support substrate 10. Figure 5 2 shows an embodiment in which three chip terminal connectors are arranged on a support substrate 10 , wherein the three chip terminal connectors are: a first chip terminal connector 12 , a second chip terminal connector 13 and a third chip terminal connector 14 .

[0034] Placing the power device chip 11 on the DBC board, specifically, the power device chip 11 is at least placed on the support substrate 10, and can also be directly placed on a chip terminal connector. Figure 5 An embodiment of placing a power device chip 11 on a first chip terminal connector 12 is shown in FIG. After placing the power device chip 11 on the DBC board, the corresponding end pins of the power device chip 11 are adapted and connected to the corresponding chip terminal connectors. Thereafter, at least one connection terminal 4 may be welded on each chip terminal connector, and the connection terminal 4 should be electrically connected to the welded chip terminal connector.

[0035] In a specific implementation, the shape of the connection terminals 4 includes a column shape or a strip shape, wherein all the connection terminals 4 are parallel to each other, and all the connection terminals 4 are located on the same side of the DBC board. Figure 52 shows an embodiment in which a connection terminal 4 is welded on each chip terminal connector. As can be seen from the above description, the connection terminal 4 can be electrically connected to the corresponding terminal pins of the power device chip 11, that is, the terminal pins of the power device chip 11 can be led out.

[0036] In one embodiment of the present invention, the power device chip 11 is welded on a chip terminal connector of the DBC board so that one end pin of the power device chip 11 is electrically connected to the welded chip terminal connector, and then the remaining end pins of the power device chip 11 are wire-bonded to the corresponding chip terminal connector, wherein: During wire bonding, the bonding wires used include aluminum wires, copper wires or copper ribbons.

[0037] It should be noted that the power device chip 11 is generally a chip formed by preliminary packaging. For example, when the power device chip 11 is formed based on an IGBT device, the power device chip 11 should include three end pins to correspond to the gate, emitter and collector of the power device chip 11. When the power device chip 11 is formed based on a power diode, the power device chip 11 should include two end pins to correspond to the anode and cathode ends of the power diode.

[0038] When the power device chip 11 is welded to a chip terminal connector, one end pin of the power device chip 11 may be welded to the corresponding chip terminal connector; Figure 5 In the embodiment, when the power device chip 11 is formed based on an IGBT device, the gate terminal of the power device chip 11 can be welded to the first chip terminal connector 12; when the power device chip 11 is based on a power diode, the cathode terminal of the power device chip 11 can be welded to the first chip terminal connector 12. In specific implementation, when welding the power device chip 11, the welding method used includes soldering, solder sheet sintering or solder paste sintering.

[0039] From the above description, it can be seen that the corresponding end pins of the power device chip 11 need to be led out to the corresponding chip terminal connector. In specific implementation, the remaining end pins of the power device chip 11 can be connected to the corresponding chip terminal connector by wire bonding. During wire bonding, the bonding wire used includes aluminum wire, copper wire or copper tape, and the wire bonding method can be consistent with the existing technology. Figure 5 In the embodiment, the remaining pins of the power device chip 11 are electrically connected to the second chip terminal connector 13 through the first bonding wire 15, and are electrically connected to the third chip terminal connector 14 through the second bonding wire 16; when the power device chip 11 is of other types, the corresponding wire bonding connection can refer to Figure 5 As well as the instructions here, I will not repeat them here.

[0040] After the corresponding power chip assembly 9 is prepared by the sampling method mentioned above, the power chip assembly 9 should be assembled on the heat sink 1 so that the heat sink 1 can be used to dissipate the heat of the power chip assembly 9 to ensure that the temperature of the power device chip 11 during the reliability test is adapted to the target test junction temperature to ensure that the actual temperature of the power device chip 11 is as close to the set target test junction temperature as possible. Through the heat dissipation of the heat sink 1, the heat generated by self-heating of the power device chip 11 during the reliability test can be quickly and effectively discharged, rather than accumulated inside the power device chip 11 to increase the temperature of the power device chip 11, thereby avoiding the temperature of the power device chip 11 being significantly higher than the set target test junction temperature, or even generating a positive feedback loop, thereby causing the temperature to continue to rise and damage the power device chip 11.

[0041] In one embodiment of the present invention, when assembling the power chip assembly 9 onto the heat sink 1, thermal grease is first applied onto the connection surface 20 of the heat sink 1 to form a thermal grease layer on the connection surface 20 of the heat sink 1, wherein the area of ​​the thermal grease layer is not less than the area of ​​the DBC board; The back side of the DBC board in the power chip assembly 9 is placed on the thermal grease layer, and then the power chip assembly 9 is fixed on the heat sink 1 using the assembly fixing part 2 .

[0042] Specifically, the heat sink 1 can generally adopt the existing commonly used form, such as the heat sink 1 has a connection surface 20 and a heat dissipation surface. Generally, the heat dissipation surface and the connection surface 20 are located on two corresponding surfaces of the heat sink 1, wherein the connection surface 20 is the surface that is mutually connected with the power chip component 9, and the heat dissipation surface is the surface used to achieve heat dissipation. A plurality of heat dissipation components are arranged on the heat dissipation surface of the heat sink 1, wherein the heat dissipation component includes heat dissipation fins 7, Figure 2~Figure 5 An embodiment of setting a plurality of heat dissipation fins 7 on the heat dissipation surface is shown in the figure. Of course, the heat sink 1 can also adopt other forms. The design of the heat sink 1 should be as large as possible to ensure sufficient heat melting and then reduce the temperature increase. The specific form can be selected according to needs to meet the heat dissipation requirements of the power chip component 9. When assembling the power chip assembly 9 on the connection surface 20, thermal grease should be coated on the connection surface 20 first to form a thermal grease layer on the connection surface 20 of the heat sink 1, so that the heat of the power chip assembly 9 can be transferred to the heat sink 1 by using the thermal grease layer. Generally, the area of ​​the thermal grease layer is not less than the area of ​​the DBC board; in addition, the thermal grease layer is generally located in the central area of ​​the connection surface 20.

[0043] After forming the thermal grease layer, the support substrate 10 is placed on the thermal grease layer. The back of the DBC board is the back of the support substrate 10. The back of the support substrate 10 specifically refers to the surface where the power device chip 11 is not provided. At this time, the power device chip 11 is located on the connection surface 20. After that, the power chip assembly 9 can be fixed on the heat sink 1 using the assembly fixture 2. When the power chip assembly 9 is fixed using the assembly fixture 2, the stability and reliability of the power device chip 11 in the power chip assembly 9 during the reliability test can be ensured.

[0044] In one embodiment of the present invention, a fixing through hole 19 adapted to the power chip component 9 is provided in the central area of ​​the component fixing member 2, and a fixing alignment groove 17 adapted to the DBC board is provided on the back side of the component fixing member 2, wherein: When the power chip assembly 9 is fixed by the assembly fixture 2, the assembly fixture 2 is aligned with the DB board by the fixed alignment groove 17, and covers the heat sink 1, and the assembly fixture 5 is fixed to the connection surface 20 of the heat sink 1 by the fixed connecting member 5. When the assembly fixture 2 is pressed on the heat sink 1, the power device chip 11 on the DBC board is exposed through the fixing member through hole 19.

[0045] Figure 6 An embodiment of the component fixing member 2 is shown in FIG. Figure 2~Figure 6 It can be seen that the component fixture 2 can be rectangular, and the component fixture 2 should generally be supported by non-conductive materials. The central area of ​​the component fixture 2 is provided with a fixture through hole 19, and the size of the fixture through hole 19 is based on the exposure of the power device chip 11. For example, three terminal blocks 4 can be passed through the component fixture 2, such as Figure 2 and Figure 3 shown.

[0046] In order to cooperate with the power chip component 9, a fixed alignment groove 17 is set on the back side of the component fixture 2, and the fixed alignment groove 17 corresponds to the edge of the supporting substrate 10. Therefore, when the power chip component 9 is fixed by the component fixture 2, the component fixture 2 is aligned with the edge of the supporting substrate 10 by using the fixed alignment groove 17, so as to achieve alignment with the power chip component 9, and after alignment, it is pressed on the connecting surface 20 of the heat sink 1. It should be noted that after alignment by using the fixed alignment groove 17, the power device chip 11 can correspond to the fixing through hole 19, so that the power device chip 11 can be exposed.

[0047] In order to improve the reliability of the connection between the component fixing member 2 and the radiator 1, the component fixing member 2 should be fixed to the radiator 1 through the fixing connecting member 5. Figure 2An embodiment of fixing the component fixture 2 to the heat sink 1 using four fixing connectors 5 is shown. Specifically, the method of fixing the component fixture 2 to the heat sink 1 using the fixing connectors 5 includes bolt connection, and the component fixture 2 is insulated from the power chip component 9 and the heat sink 1.

[0048] It should be noted that, if the method of fixing the component fixing part 2 to the radiator 1 by means of a bolt connection using the fixing connector 5, the fixing connector 5 should be in the form of a bolt. At this time, a fixing connector connection hole 6 should be provided on the component fixing part 2, and a radiator connection hole 8 should be provided on the radiator 1, wherein the fixing connector connection hole 6 and the radiator connection hole 8 generally correspond to each other, and a fixing connector 5 can be screwed into the fixing connector connection hole 6 and the radiator connection hole 8, thereby realizing a fixed connection between the component fixing part 2 and the radiator 1, and then fixing the power chip component 9 on the connection surface 20 of the radiator 1 through the component fixing part 2. Figure 6 In the embodiment, a fixing positioning groove 18 is further provided in the inner circle of the component fixing member 2 , and the component fixing member 2 can be sleeved on the radiator 1 by using the fixing positioning groove 18 .

[0049] In one embodiment of the present invention, the insulating isolation protection layer 3 is prepared, comprising: An insulating isolation protection material is provided and injected into the fixing member through hole 19 to form an insulating isolation protection layer 3 after the insulating isolation protection material is solidified, and the insulating isolation protection layer 3 is completely located in the fixing member through hole 19 .

[0050] From the above description, it can be seen that after the power chip component 9 is fixed on the heat sink 1 using the component fixing part 2, the fixing part through hole 19 is empty at this time, which is not conducive to the protection of the power device chip 1. An insulating isolation protective layer 3 should be prepared in the fixing part through hole 19, and the insulating isolation protective layer 3 is used to cover the power chip component 9, but the terminal 4 passes through the insulating isolation protective layer 3 so that the connection can be achieved during the reliability test.

[0051] In a specific implementation, the insulating isolation protection material is at least silica gel; the temperature that the component fixing part 2 can withstand is higher than the reliability temperature of the power device chip 1.

[0052] In one embodiment of the present invention, the silicone material used for the insulating isolation protection material can be selected according to needs, so as to achieve insulation isolation and protection for the power chip assembly 9. After selecting the type of insulating isolation protection material, injection and curing can be achieved by commonly used technical means in this technical field. It should be noted that the component fixture 2 should be made of high temperature resistant material, such as the temperature that the component fixture 2 can withstand is higher than the reliability temperature of the power device chip 11, wherein the reliability temperature of the power device chip 11 specifically refers to the maximum junction temperature of the power device chip 11; in addition, the component fixture 2 should also remain unchanged at high temperatures to ensure the stability and reliability of the power chip assembly 9 on the heat sink 1.

[0053] In summary, the present invention can obtain a test sample suitable for reliability testing. Specifically, the test sample is prepared by the preparation method.

[0054] Specifically, after the test sample is prepared, the test sample can be subjected to reliability testing using existing commonly used reliability testing equipment, and after the reliability test, the process and results of the reliability test are tested and evaluated, and finally the product or process is evaluated to see whether it has passed the assessment. It should be noted that the reliability testing equipment, the reliability testing process, and the evaluation method can be consistent with the existing technology, subject to the need to achieve reliability testing, and will not be repeated here.

Claims

1. A method for preparing a test sample suitable for reliability testing, characterized in that: The test sample preparation method comprises: Providing a power device chip to be tested for reliability, and assembling the power device chip onto a DBC board to form a power chip assembly; The power chip assembly formed as above is assembled onto a heat sink, so as to utilize the heat sink to dissipate heat from the power chip assembly, wherein: When performing reliability testing on a power device chip, after heat dissipation by a heat sink, at least the test temperature of the power device chip is adapted to the target test junction temperature; When the power chip assembly is assembled on the heat sink, the power chip assembly is fixed on the heat sink by using the assembly fixing member, wherein after the power chip assembly is fixed on the heat sink by using the assembly fixing member, at least the power device chip of the power chip assembly is in an exposed state; An insulating isolation protection layer is prepared in the component fixture, and the insulating isolation protection layer is covered on the power chip component, so as to utilize the insulating isolation protection layer to perform insulating isolation protection on the power chip component.

2. The method for preparing a test sample suitable for reliability testing according to claim 1, characterized in that: When assembling the power device chip onto the DBC board and forming a power chip assembly, it includes: A DBC board adapted to a power device chip is provided, wherein the DBC board comprises a supporting substrate and a chip terminal connector adapted to the power device chip, and the chip terminal connector is arranged on the supporting substrate; Place the power device chip on the DBC board, and make the corresponding end pins of the power device chip fit and connect with the corresponding chip terminal connector on the DBC board; At least one connection terminal is welded on each chip terminal connection body of the DBC board, and the connection terminal is electrically connected to the welded chip terminal connection body.

3. The method for preparing a test sample suitable for reliability testing according to claim 2, characterized in that: The power device chip is welded on a chip terminal connector of the DBC board so that one end pin of the power device chip is electrically connected to the welded chip terminal connector, and then the remaining end pins of the power device chip are wire-bonded to the corresponding chip terminal connector, wherein: During wire bonding, the bonding wires used include aluminum wires, copper wires or copper ribbons.

4. The method for preparing a test sample suitable for reliability testing according to claim 2, characterized in that: The shape of the terminal block includes column or strip, wherein: All the wiring terminals are parallel to each other and all the wiring terminals are located on the same side of the DBC board.

5. The method for preparing a test sample suitable for reliability testing according to any one of claims 1 to 4, characterized in that: When assembling the power chip assembly onto the heat sink, first apply thermal grease on the connection surface of the heat sink to form a thermal grease layer on the connection surface of the heat sink, wherein the area of ​​the thermal grease layer is not less than the area of ​​the DBC board; The back side of the DBC board in the power chip assembly is placed on the thermal grease layer, and then the power chip assembly is fixed on the heat sink using an assembly fixing piece.

6. The method for preparing a test sample suitable for reliability testing according to claim 5, characterized in that: The central area of ​​the component fixture is provided with a fixture through hole adapted to the power chip component, and the back of the component fixture is provided with a fixed alignment groove adapted to the DBC board, wherein: When the power chip assembly is fixed by the assembly fixing piece, the assembly fixing piece is aligned with the DB board by the fixing alignment groove and covers the heat sink, and the assembly fixing piece is fixed to the connection surface of the heat sink by the fixing connecting piece, wherein when the assembly fixing piece is pressed on the heat sink, the power device chip on the DBC board is exposed through the fixing piece through hole.

7. The method for preparing a test sample suitable for reliability testing according to claim 6, characterized in that: A plurality of heat dissipation components are arranged on the heat dissipation surface of the heat sink, wherein the heat dissipation components include heat dissipation fins; The method of fixing the component fixing part on the heat sink by using the fixing connecting part includes bolt connection, and the component fixing part is insulated from the power chip component and the heat sink.

8. The method for preparing a test sample suitable for reliability testing according to claim 6, characterized in that: When preparing the insulating isolation protective layer, it includes: An insulating isolation protection material is provided and injected into the fixing member through hole to form an insulating isolation protection layer after the insulating isolation protection material is solidified, and the insulating isolation protection layer is completely located in the fixing member through hole.

9. The method for preparing a test sample suitable for reliability testing according to claim 8, characterized in that: The insulating isolation protection material is at least silica gel; the temperature that the component fixing part can withstand is higher than the reliability temperature of the power device chip.

10. A test sample suitable for reliability testing, characterized in that: The test sample is prepared by the preparation method described in any one of claims 1 to claim 9.

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