A preparation method and application for rapidly generating an all-intermetallic compound joint

Abstract

A preparation method and application for rapidly generating an all-intermetallic compound joint, which belong to the technical field of electronic packaging. Method: First, pretreatment; Second, prepare an electroplating solution; Third, electroplate; Fourth, ultrasonically clean the tin foil; Fifth, prepare a copper-tin-copper "sandwich" structure; Sixth, brazing to obtain an all-intermetallic compound joint. The present invention prepares a copper micro-nano surface structure with a (111) crystal orientation through a green electroplating method. By forming a micro-nano structure-solder-micro-nano structure solder joint, the tip of the copper micro-nano structure with a special size effect directly pierces the oxide film on the surface of the solder and reaches the interior for diffusion, so as to achieve the purpose of rapidly generating an all-intermetallic compound joint under micro-pressure and low-temperature conditions. The all-intermetallic compound joint prepared by the present invention has excellent high-temperature resistance and can meet the requirements of high-temperature service of third-generation semiconductor power devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic packaging, and particularly relates to a preparation method and application for rapidly generating a full intermetallic compound joint. Background Art

[0002] With the rapid development of semiconductor technology and the realization of the goals of high integration and miniaturization of electronic devices, there has emerged the problem that power devices cannot dissipate heat quickly in a narrow space, resulting in long-term service at high temperatures. Especially in special environments such as nuclear energy and aerospace, the operating temperature of semiconductor devices exceeds 500 °C. Traditional silicon-based devices will fail due to the junction temperature effect when the operating temperature exceeds 150 °C, unable to meet the requirements of scientific and technological development. This situation has been solved until the emergence of the third-generation semiconductors. However, traditional packaging technologies and interfacial connection materials still cannot meet the requirements for devices to operate under extreme high-temperature conditions. If the traditional soldering method is used to solve the problem, higher melting point solders and higher process temperatures are required, and the high temperature generated will directly damage the chip and result in high residual stress, thus damaging the packaging system. Therefore, the development of high-temperature service connection technologies corresponding to the third-generation semiconductors is of great significance.

[0003] Currently, particle sintering, high-temperature soldering, and transient liquid phase bonding technology (TLP) are the mainstream packaging technologies for the third-generation semiconductor devices. Au-based, Bi-based, Sn-based, and high-Pb solders are the commonly used high-temperature interconnect materials. Among them, Sn-based solders are widely used because of their moderate price, good electrical and thermal conductivity, and excellent wettability. However, its melting point is lower than the requirements of high-temperature interconnect packaging, and the problem of low shear strength also needs to be solved. The properties of the materials produced by particle sintering are closely related to those of nanomaterials. The nanoscale size of nanomaterials endows the materials with special surface effects, interfacial effects, dielectric effects, and quantum size effects. Nanomaterials can be spontaneously connected at low temperatures, and still maintain their physical properties as metals after being sintered into bulk materials. Therefore, it meets the working environment requirements of the third-generation semiconductors within a certain range. However, after the sintering of nanometer particles, there will be problems such as particle agglomeration, a large number of pores, and high costs. The essence of TLP is that after the low melting point metal and the high melting point metal are bonded at low temperature, an intermetallic compound with a high melting point is generated. Through the intermetallic compound as the connecting layer, the interconnect material can meet the high-temperature working environment. The solder joints prepared by the TLP technology have a sandwich structure, with the low melting point metal sandwiched between the high melting point metals. After welding, the intermediate layer is composed of metal compounds. However, when connecting, it requires long-term continuous high-temperature heating, resulting in relatively high energy consumption. Summary of the Invention

[0004] The object of the present invention is to solve the problems of long manufacturing time, large applied pressure, and poor physical and mechanical properties of the joint in the existing high-temperature resistant welding joint of power chips, and to provide a preparation method and application for rapidly generating an all-intermetallic compound joint.

[0005] The present invention provides a method for rapidly preparing an all-intermetallic compound joint for power device packaging by transient liquid phase bonding technology under micro-pressure and low-temperature conditions.

[0006] A preparation method for rapidly generating an all-intermetallic compound joint is specifically completed according to the following steps:

[0007] I. Pretreatment:

[0008] First, use sandpaper to polish the surface of the pure copper plate, then pickling, then rinse with deionized water, and dry to obtain the pretreated pure copper plate;

[0009] II. Configure the electroplating solution:

[0010] Add copper sulfate pentahydrate, boric acid, and methylene green to deionized water in sequence, heat and stir magnetically to obtain the electroplating solution;

[0011] III. Electroplating:

[0012] Immerse the pretreated pure copper plate into the electroplating solution, use direct current electroplating, and then clean and dry the electroplated sample to obtain a copper plate with a copper micro-nano structure;

[0013] IV. Put the tin foil into absolute ethanol for ultrasonic cleaning, take it out and dry it to obtain the cleaned tin foil;

[0014] V. Place the cleaned tin foil between two copper plates with copper micro-nano structures. The tin foil is in contact with the copper micro-nano structures on the surfaces of the upper and lower copper plates respectively to form a copper-tin-copper "sandwich" structure, and then apply soldering paste around the "sandwich" structure;

[0015] VI. Place the copper-tin-copper "sandwich" structure on the working table of a hot press, control the heating temperature at 250 °C, and perform brazing at 250 °C for 1 min to 7 min. Continuously apply pressure during the brazing process to obtain an all-intermetallic compound joint.

[0016] The principle of the present invention:

[0017] I. The present invention micronanostructures the surface of the substrate, enabling the nano tips with special size effects to directly pierce the oxide film on the surface of the solder and reach the interior of the solder, making it easier for auto-diffusion and recrystallization to occur on the surface of the copper substrate. Moreover, the intermetallic compounds generated can still serve at high temperatures, improving the welding efficiency of the transient liquid phase bonding technology (TLP), thereby reducing the high energy consumption problem in TLP bonding. In summary, in order to reduce the welding conditions in the TLP process and promote the diffusion bonding between the substrate and the interlayer, it is very meaningful to prepare a micronano-scale coating on the substrate surface. The interlayer of the transient liquid phase bonding technology (TLP) has a relatively low cost, and the generated intermetallic compounds can meet the conditions for high-temperature service.

[0018] II. The present invention prepares a copper micro-nano surface structure with (111) crystal orientation through a green electrodeposition method. By forming a micro-nano structure - solder - micro-nano structure solder joint, the tips of the copper micro-nano structures with special size effects directly pierce the oxide film on the surface of the solder and reach the interior for diffusion, thereby achieving the purpose of quickly generating a full intermetallic compound joint under micro-pressure and low-temperature conditions. The full intermetallic compound joint prepared by the present invention has excellent high-temperature resistance and can meet the requirements for high-temperature service of third-generation semiconductor power devices.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] I. When sanding with sandpaper, 400#, 800#, 1500#, 3000#, and 5000# sandpapers are used in sequence. The purpose is to remove the oxide layer on the surface of the material. The copper plate is polished on a polishing machine equipped with 2000# water sandpaper, and micro-nano grooves are constructed on the surface of the material through physical grinding, enabling ions to discharge at the original micro-nano protrusions, making the grains finer and the bonding force between the copper substrate and the deposition layer stronger.

[0021] II. The electrodeposition solution mainly includes copper sulfate pentahydrate, boric acid, and Janus green. The exchange time of the electrodeposition solution is between 4 min and 16 min, and the current density is between 0.4 A / dm 2 ~2.4 A / dm 2 , and the temperature is between 20 and 60 °C. The above components form a solution suitable for electroplating a copper layer with a large current density. Using current density filling will not cause problems such as voids and burning, and the surface is bright, which can effectively prevent the defects of uneven electrodeposition layers caused by voids and burning.

[0022] III. During welding, the copper micro-nano structure prepared by electrodeposition greatly improves the wettability of liquid tin, eliminates interface voids, and reduces the bonding time and bonding temperature.

[0023] IV. The method provided by the present invention for rapidly generating a fully intermetallic compound joint under micro-pressure and low-temperature conditions has the advantages of simple process, easy parameter control, high process repeatability, and stable system, meeting the requirements of energy conservation and emission reduction in the current policy development, and also having better production and application prospects. Description of the Drawings

[0024] Figure 1 It is a surface topography diagram. In the figure, (a) is the copper plate with copper micro-nano structure obtained in Step 3 of Example 1, (b) is the copper plate with copper micro-nano structure obtained in Step 3 of Example 2, (c) is the copper plate with copper micro-nano structure obtained in Step 3 of Example 3, and (d) is an ordinary copper plate without any treatment;

[0025] Figure 2 It is an XRD diagram of the copper micro-nano structure on the surface (111) crystal orientation of the copper plates prepared in Examples 1, 4, 5 and 6 and an ordinary copper plate without any treatment;

[0026] Figure 3 It is a cross-sectional view of the fully intermetallic compound joints prepared in Examples 1 and 7. In the figure, (a) is Example 1 and (b) is Example 7;

[0027] Figure 4 It is a fracture diagram of the shear test of the fully intermetallic compound joints prepared in Examples 1 and 7;

[0028] Figure 5 It is the shear strength of the solder joints. (a) is Example 1, (b) is Example 2, (c) is Example 3, and (d) is Comparative Example 1. Detailed Embodiments

[0029] Detailed Embodiment 1: A preparation method for rapidly generating a fully intermetallic compound joint in this embodiment is specifically completed according to the following steps:

[0030] I. Pretreatment:

[0031] First, use sandpaper to polish the surface of the pure copper plate, then pickling, and then rinse with deionized water and dry to obtain the pretreated pure copper plate;

[0032] II. Prepare the electroplating solution:

[0033] Add copper sulfate pentahydrate, boric acid and methylene green to deionized water in sequence, heat and stir magnetically to obtain the electroplating solution;

[0034] III. Electroplating:

[0035] Immerse the pretreated pure copper plate into the electroplating solution, use direct current electroplating, and then clean and dry the electroplated sample to obtain a copper plate with copper micro-nano structure;

[0036] IV. Put the tin foil into absolute ethanol for ultrasonic cleaning, take it out and dry it to obtain the cleaned tin foil.

[0037] V. Place the cleaned tin foil between two copper plates with copper micro-nano structures. The tin foil is in contact with the copper micro-nano structures on the surfaces of the upper and lower copper plates respectively to form a copper-tin-copper "sandwich" structure, and then apply soldering paste around the "sandwich" structure.

[0038] VI. Place the copper-tin-copper "sandwich" structure on the working table of a hot press welder, control the heating temperature at 250 °C, perform brazing at 250 °C for 1 min to 7 min, and continuously apply pressure during the brazing process to obtain a full intermetallic compound joint.

[0039] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that in Step I, the surface of the pure copper plate is polished successively with 400#, 800#, 1500#, 3000#, and 5000# sandpapers, and then the copper plate is polished on a polishing machine equipped with 2000# water sandpaper for 1 min. Other steps are the same as those in Specific Embodiment 1.

[0040] Specific Embodiment 3: The difference between this embodiment and either Specific Embodiment 1 or 2 is that in Step I, the polished pure copper sheet is pickled with sulfuric acid with a mass fraction of 10% for 25 s to 35 s, and then rinsed 3 to 5 times with deionized water. Other steps are the same as those in Specific Embodiment 1 or 2.

[0041] Specific Embodiment 4: The difference between this embodiment and any one of Specific Embodiments 1 to 3 is that in Step II, the concentration of copper sulfate pentahydrate in the electrodeposition solution is 0.2 mol / L, the concentration of boric acid is 0.2 mol / L to 0.4 mol / L, and the concentration of Janus green is 0.1 g / L to 0.4 g / L; preferably, the concentration of boric acid in the electrodeposition solution is 0.3 mol / L, and the concentration of Janus green is 0.2 g / L to 0.3 g / L. Other steps are the same as those in Specific Embodiments 1 to 3.

[0042] Specific Embodiment 5: The difference between this embodiment and any one of Specific Embodiments 1 to 4 is that in Step II, the heating temperature is 40 °C to 45 °C; the speed of magnetic stirring in Step II is 800 r / min to 1200 r / min; in Step II, heat and stir magnetically until copper sulfate pentahydrate, boric acid, and Janus green are completely dissolved in deionized water. Other steps are the same as those in Specific Embodiments 1 to 4.

[0043] Specific Embodiment 6: The difference between this embodiment and any one of Specific Embodiments 1 to 5 is that in Step III, the pretreated pure copper plate is immersed in the electrodeposition solution at a temperature of 20 °C to 60 °C, and then at a current density of 0.4 A / dm 2~2.4 A / dm 2 Electrodeposit for 4 min to 16 min under the condition of; preferably, electrodeposit for 12 min to 16 min under the condition that the current density is 1.2 A / dm 2 ~2.4 A / dm 2 . Other steps are the same as those in the first to fifth specific embodiments.

[0044] Specific embodiment seven: The difference between this embodiment and any one of the first to sixth specific embodiments is that: the cleaning in step three is: sequentially use anhydrous ethanol and deionized water to clean the electrodeposited sample 1 to 3 times respectively. Other steps are the same as those in the first to sixth specific embodiments.

[0045] Specific embodiment eight: The difference between this embodiment and any one of the first to seventh specific embodiments is that: the thickness of the tin foil described in step four is 10 μm to 50 μm; the soldering paste described in step five is AMTECH soldering paste from the United States. Other steps are the same as those in the first to seventh specific embodiments.

[0046] Specific embodiment nine: The difference between this embodiment and any one of the first to eighth specific embodiments is that: in step six, brazing is carried out at 250 °C for 5 min to 7 min, and the pressure continuously applied during the brazing process is 0.07 MPa. Other steps are the same as those in the first to eighth specific embodiments.

[0047] Specific embodiment ten: The difference between this embodiment and any one of the first to ninth specific embodiments is that: the all-metal intermetallic compound joint is used for power device packaging. Other steps are the same as those in the first to ninth specific embodiments.

[0048] The following examples are used to verify the beneficial effects of the present invention:

[0049] Example 1: A preparation method for rapidly generating an all-metal intermetallic compound joint, which is specifically completed according to the following steps:

[0050] I. Pretreatment:

[0051] Prepare two sizes of copper plates, with sizes of 38 mm × 25 mm × 1 mm and 4 mm × 4 mm × 1 mm respectively; polish the two sizes of copper plates respectively, that is, first polish the surface of the pure copper plate with 400#, 800#, 1500#, 3000#, and 5000# sandpapers in sequence, then polish the copper plate on a polishing machine equipped with 2000# water sandpaper for 1 min, then pickle the polished pure copper sheet with 10% sulfuric acid by mass for 30 s, and then rinse with deionized water 5 times; dry to obtain the pretreated pure copper plate;

[0052] II. Configure the electrodeposition solution:

[0053] Add copper sulfate pentahydrate, boric acid, and Janus green to deionized water in sequence, heat to 40 °C, and magnetically stir at 40 °C and a stirring speed of 1000 r / min until copper sulfate pentahydrate, boric acid, and Janus green are completely dissolved in deionized water to obtain an electrodeposition solution;

[0054] In the electrodeposition solution described in step 2, the concentration of copper sulfate pentahydrate is 0.2 mol / L, the concentration of boric acid is 0.3 mol / L, and the concentration of Janus green is 0.2 g / L;

[0055] III. Electrodeposition:

[0056] Immerse the pretreated pure copper plate into the electrodeposition solution at a temperature of 40 °C, and then electro-deposit for 12 min under the condition of a current density of 1.2 A / dm 2 Then, wash the electro-deposited sample with absolute ethanol and deionized water once each and blow dry to obtain a copper plate with a copper micro-nano structure;

[0057] IV. Put the tin foil into absolute ethanol for ultrasonic cleaning for 1 min, take it out and dry it to obtain the cleaned tin foil;

[0058] The thickness of the tin foil described in step 4 is 20 μm;

[0059] V. Cut the cleaned tin foil into 4 mm × 4 mm, place the 38 mm × 25 mm × 1 mm copper plate with a copper micro-nano structure at the bottom, place the 4 mm × 4 mm × 1 mm copper plate with a copper micro-nano structure on top, place the cleaned tin foil between the two copper plates with a copper micro-nano structure, and make the tin foil contact the copper micro-nano structures on the surfaces of the upper and lower copper plates respectively to form a copper-tin-copper "sandwich" structure, and then apply soldering paste around the "sandwich" structure;

[0060] The soldering paste described in step 5 is AMTECH soldering paste from the United States;

[0061] VI. Place the copper-tin-copper "sandwich" structure on the working table of a hot press, control the heating temperature to 250 °C, perform brazing at 250 °C for 7 min, and continuously apply a pressure of 0.07 MPa during the brazing process to obtain a full intermetallic compound joint;

[0062] The full intermetallic compound joint obtained in step VI is used for power device packaging.

[0063] Example 2: The difference between this example and Example 1 is that in step 3, the pretreated pure copper plate is immersed into the electrodeposition solution at a temperature of 40 °C, and then electro-deposited for 12 min under the condition of a current density of 0.4 A / dm 2 Other steps and parameters are the same as those in Example 1.

[0064] Example 3: The difference between this example and Example 1 is that in the electroplating solution described in Step 2, the concentration of copper sulfate pentahydrate is 0.2 mol / L, the concentration of boric acid is 0.3 mol / L, and the concentration of Janus green is 0.1 g / L. Other steps and parameters are the same as those in Example 1.

[0065] Example 4: The difference between this example and Example 1 is that the pretreated pure copper plate is immersed in the electroplating solution at a temperature of 40 °C, and then electroplated for 16 min under the condition of a current density of 1.2 A / dm 2 . Other steps and parameters are the same as those in Example 1.

[0066] Example 5: The difference between this example and Example 1 is that the pretreated pure copper plate is immersed in the electroplating solution at a temperature of 40 °C, and then electroplated for 8 min under the condition of a current density of 1.2 A / dm 2 . Other steps and parameters are the same as those in Example 1.

[0067] Example 6: The difference between this example and Example 1 is that the pretreated pure copper plate is immersed in the electroplating solution at a temperature of 40 °C, and then electroplated for 4 min under the condition of a current density of 1.2 A / dm 2 . Other steps and parameters are the same as those in Example 1.

[0068] Example 7: The difference between this example and Example 1 is that brazing is carried out at 250 °C for 5 min in Step 6. Other steps and parameters are the same as those in Example 1.

[0069] Control Example 1:

[0070] I. Put the tin foil into absolute ethanol for ultrasonic cleaning for 1 min, take it out and dry it to obtain the cleaned tin foil;

[0071] The thickness of the tin foil described in Step 1 is 20 μm;

[0072] II. Cut the cleaned tin foil to 4 mm × 4 mm, place the copper plate with dimensions of 38 mm × 25 mm × 1 mm that has not undergone any process treatment at the bottom, place the copper plate with dimensions of 4 mm × 4 mm × 1 mm that has not undergone any process treatment on top, place the cleaned tin foil between the two copper plates, and the tin foil is in contact with the upper and lower surfaces of the two pure copper plates respectively to form a copper-tin-copper "sandwich" structure. Then, apply soldering paste around the "sandwich" structure;

[0073] The soldering paste described in Step 2 is AMTECH soldering paste from the United States;

[0074] III. Place the copper-tin-copper "sandwich" structure on the workbench of a hot press welder, control the heating temperature at 250°C, perform brazing at 250°C for 7 minutes, and continuously apply a pressure of 0.07 MPa during the brazing process to obtain a full intermetallic compound joint.

[0075] Figure 1 Figure 4 shows the surface morphology diagrams. In the figure, (a) is the copper plate with copper micro-nano structures obtained in Step III of Example 1, (b) is the copper plate with copper micro-nano structures obtained in Step III of Example 2, (c) is the copper plate with copper micro-nano structures obtained in Step III of Example 3, and (d) is an ordinary copper plate without any treatment.

[0076] From Figure 1 it can be seen that the surface of the micro-nano structure prepared in Example 1 has a unique, uniform, and dense conical morphology as shown in Figure 1 (a). Compared with the fine granular structure prepared during the electroplating process when the current density is lower than 0.8 A / dm 2 as shown in Figure 1 (b), and the tumor-like structure prepared without adding or adding less than 0.1 g / L of Janus green in the electroplating solution as shown in Figure 1 (c), as well as the smooth and flat surface of the ordinary copper plate without any treatment as shown in Figure 1 (d).

[0077] Figure 2 Figure 5 is the XRD diagram of the copper micro-nano structures on the surface of the copper plates prepared in Examples 1, 4, 5, and 6 and an ordinary copper plate without any treatment.

[0078] From Figure 2 it can be seen that there are significant differences in the diffraction peaks of the (111) crystal phase between the pure copper plate without electroplating and the copper plates with surface micro-nano structures after electroplating for 4 - 16 minutes. As the electroplating time increases, the diffraction peaks of the (111) crystal phase gradually increase, indicating that the crystal crystallization degree of the (111) crystal phase gradually enhances.

[0079] Figure 3 Figure 6 is the cross-sectional view of the full intermetallic compound joints prepared in Examples 1 and 7. In the figure, (a) is Example 1 and (b) is Example 7.

[0080] The cross-sectional view of the full intermetallic compound joint prepared in Example 1 is shown in Figure 3 (a). It can be seen that the joint has been completely formed, and it can be observed that the Cu6Sn5 at both ends has completely come into contact and fused, and the entire interface is completely filled with IMC compounds without observing any remaining tin islands. The cross-sectional view of the full intermetallic compound joint prepared in Example 7 is shown in Figure 3 (b). The heads of the scallop-shaped Cu6Sn5 at the upper and lower ends begin to come into contact and fuse with each other, and independent tin islands are generated in the uncontacted intermetallic compound layer.

[0081] Figure 4 Fracture diagrams of the shear tests of the all-intermetallic compound joints prepared in Examples 1 and 7;

[0082] The fracture diagram of the shear test of the all-intermetallic compound joint prepared in Example 1 is shown in Figure 4 (a). It can be seen that the fracture surface is relatively flat, without elongated dimples, and no exposed Cu substrate is found on the fracture surface. Therefore, the cracks all occur inside Cu6Sn5, and it is a transgranular fracture of Cu6Sn5. There is no plastic deformation in this area, which is a brittle fracture.

[0083] The fracture diagram of the shear test of the all-intermetallic compound joint prepared in Example 7 is shown in Figure 4 (b). It can be seen that Cu6Sn5 wrapped with Sn is distributed at the fracture interface, resulting in an uneven interface. It can be seen that the fracture mainly occurs inside Cu6Sn5, Cu6Sn5 / Cu3Sn, and Cu3Sn. At this time, the fracture mechanism is brittle fracture.

[0084] The conical tips with unique morphologies can greatly improve the bonding force between the substrate surface and the solder, and further enhance the mechanical properties of the solder joints. The shear strength of the solder joints prepared based on the surface micro-nano structures prepared by different electroplating processes is shown in Figure 5 ;

[0085] Figure 5 where is the shear strength of the solder joint, (a) is Example 1, (b) is Example 2, (c) is Example 3, and (d) is Comparative Example 1;

[0086] From Figure 5 it can be known that: compared with the shear strength of the solder joints prepared in Example 1, the surface of the fine granular structure has no obvious conical tips, which will cause the formation of intermetallic compounds between the solder and the substrate to slow down and reduce the connection strength; the tumor-like structure, due to its uneven cluster morphology and large gaps, further slows down the reaction with the solder, and the shear strength is further reduced; the untreated ordinary copper plate has the slowest reaction with the solder because it does not have a micro-nano structure with special surface energy, and the shear strength is the lowest.

Claims

1. A preparation method for quickly generating an all-intermetallic compound joint, characterized in that The preparation method is specifically completed according to the following steps: I. Pretreatment: First, use sandpaper to polish the surface of the pure copper plate, then pickle it with acid, and then rinse it with deionized water and dry it to obtain the pretreated pure copper plate; II. Prepare the electroplating solution: Add copper sulfate pentahydrate, boric acid, and Janus green to deionized water in sequence, heat and stir magnetically to obtain the electroplating solution; In the electroplating solution described in step II, the concentration of copper sulfate pentahydrate is 0.2 mol / L, the concentration of boric acid is 0.3 mol / L, and the concentration of Janus green is 0.2 g / L; III. Electroplating: Immerse the pre-treated pure copper plate into the electrodeposition solution at a temperature of 40 °C, and then electro-deposit for 12 min under the condition of a current density of 1.2 A / dm 2 , and then wash and dry the electro-deposited sample to obtain a copper plate with a copper micro-nano structure; IV. Put the tin foil into absolute ethanol for ultrasonic cleaning, take it out and dry it to obtain the cleaned tin foil; V. Place the cleaned tin foil between two copper plates with copper micro-nano structures. The tin foil is in contact with the copper micro-nano structures on the surfaces of the upper and lower copper plates respectively to form a copper-tin-copper "sandwich" structure, and then apply solder paste around the "sandwich" structure; VI. Place the copper-tin-copper "sandwich" structure on the working table of a hot press welding machine, control the heating temperature at 250 °C, perform brazing at 250 °C for 7 min, and continuously apply a pressure of 0.07 MPa during the brazing process. Continuously apply pressure during the brazing process to obtain a full intermetallic compound joint.

2. The preparation method of a method for rapidly generating an all-intermetallic compound joint according to claim 1, characterized in that In step I, polish the surface of the pure copper plate with 400#, 800#, 1500#, 3000#, and 5000# sandpapers in sequence, and then polish the copper plate on a polishing machine equipped with 2000# water sandpaper for 1 min.

3. The preparation method of a rapid generation of an all-intermetallic compound joint according to claim 1, characterized in that In step I, pickle the polished pure copper sheet with 10% sulfuric acid by mass for 25 s to 35 s, and then rinse it with deionized water 3 to 5 times.

4. The preparation method for rapidly generating an all-intermetallic compound joint according to claim 1, wherein The heating temperature described in step II is 40 °C to 45 °C; the magnetic stirring speed described in step II is 800 r / min to 1200 r / min; in step II, heat and stir magnetically until copper sulfate pentahydrate, boric acid, and Janus green are completely dissolved in deionized water.

5. The preparation method of a rapid generation of an all-intermetallic compound joint according to claim 1, characterized in that The cleaning described in step III is: clean the electroplated sample with absolute ethanol and deionized water 1 to 3 times in sequence.

6. The preparation method of a method for rapidly generating an all-intermetallic compound joint according to claim 1, characterized in that The thickness of the tin foil described in step IV is 10 μm to 50 μm; the solder paste described in step V is AMTECH solder paste from the United States.

7. Use of an all-intermetallic compound joint prepared by the preparation method according to claim 1, characterized in that The full intermetallic compound joint is used for power device packaging.

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