Wafer and metal bump bonding structure and manufacturing process thereof

Abstract

The invention relates to a wafer and metal bump bonding structure and a manufacturing process thereof, and relates to the technical field of chip manufacturing, and the process comprises the following steps: S1, providing a metal sheet and a wafer; s2, a supporting film is attached to one face of the metal sheet, a sintering face is manufactured on the other face of the metal sheet, and a metal protruding block is obtained; s3, manufacturing a slurry layer on the wafer, and placing the surface, with the sintering surface, of the metal bump on the slurry layer; or manufacturing a dry slurry film on the sintering surface of the metal bump, and placing the surface, with the dry slurry film, of the metal bump in the lead bonding area of the wafer; s4, sintering the metal bump and the wafer to obtain a bonding structure; and S5, cutting the bonding structure to separate out single chips. According to the invention, the thickness of the metal bump bonded by the wafer is controlled to be 50-300 microns, so that the metal bump can be conveniently bonded with a thick copper wire or a thick copper sheet in subsequent packaging or can be directly and inversely arranged on the substrate, and the current-carrying capability and the heat dissipation capability of the chip are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of chip manufacturing, and specifically discloses a wafer and metal bump bonding structure and a manufacturing process thereof. Background Art

[0002] The patent application number is CN106170856A, and the patent name is "Patent application for a bracket and clip with a sinterable curable paste connected to a semiconductor element, a sintering paste, a production process and a use". It discloses the use of pre-coating sintering paste on a bonding copper sheet, and then on the chip bonding area, through a pressure sintering process to form a bond between the chip and the pin; this process has more stringent requirements on the size of the chip bonding area. Due to the limitations of the glue coating process, it is not suitable for smaller bonding areas (usually less than 2mm×2mm), and there are problems such as copper sheet drift causing short circuits and inconvenience in operation, and there is a problem of inconvenience in gluing for copper sheets with height differences.

[0003] The patent application number is TW202345248A, and the patent name is "Sinter-ready multi-layer wire / ribbon pad and process for die top attachment". It discloses the use of pre-coating on the copper sheet and the same pressure sintering process to sinter to the chip bonding area; due to the limitations of the pre-coating process, there are also size requirements for the chip bonding area, and it is also not suitable for smaller bonding areas. At the same time, due to the requirements of the characteristics of the pre-coated metal film, after the pre-coating of the metal film, it is necessary to cover the exposed side of the metal film with a protective film to prevent the metal film from being damaged or oxidized during the transfer process. This causes the problem of metal film damage and inconvenience in operation during the subsequent film removal process. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a wafer and metal bump bonding structure and a manufacturing process thereof, so as to solve the problems of metal layer damage and cracking caused by insufficient metal layer thickness in the chip wire bonding area during the manufacturing process of traditional semiconductor devices, and at the same time provide sufficient metal bump thickness to facilitate bonding thick copper wires or thick copper sheets, or flip-chip mounting on a substrate, thereby improving the current carrying capacity and heat dissipation capacity of the chip. Compared with traditional processes, the present invention has a simple process, high metal layer bonding strength, strong reliability, and low cost, and has broad application prospects, especially in the field of power semiconductor devices based on third-generation semiconductor silicon carbide.

[0005] The technical solution adopted in the present invention is:

[0006] A process for manufacturing a wafer and metal bump bonding structure, wherein the process comprises the following steps:

[0007] Step S1: providing a metal sheet and a wafer;

[0008] Step S2: attaching a support film to one side of the metal sheet, chemically etching the other side of the metal sheet to form a sintered surface, forming a support frame around the sintered surface, forming a plurality of spaced metal bumps within the support frame of the sintered surface, and cleaning to obtain metal bumps with a support frame and a support film;

[0009] Step S3, forming a slurry layer on the wire bonding area of ​​the wafer, and placing one side of the metal bump on the slurry layer; or forming a dry slurry film on the sintered surface of the metal bump, and placing one side of the dry slurry film on the wire bonding area of ​​the wafer;

[0010] Step S4, sintering the metal bumps and the wafer in step S3, and removing the support film and the support frame to obtain a bonding structure;

[0011] Step S5: cutting the bonded structure to separate individual chips.

[0012] Preferably, in the manufacturing process of the wafer and metal bump bonding structure, the material of the metal sheet in step S1 is selected from one of copper, copper-molybdenum alloy, and tungsten-copper alloy, and the thickness of the metal sheet is 50-300 microns; step S2 also includes: electroplating silver on the sintered surface of the metal sheet to form a sintered surface with a silver layer, and the thickness of the silver layer is 1-4 microns.

[0013] Preferably, the process for manufacturing the wafer and metal bump bonding structure, wherein step S3 comprises preparing a slurry layer on the wire bonding area of ​​the wafer and placing one side of the metal bump on the slurry layer, specifically comprises the following steps:

[0014] Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry;

[0015] Step S32: Covering the wire bonding area of ​​the wafer with a layer of wet slurry by screen printing or dispensing to form a slurry layer with a thickness of 10-200 μm;

[0016] Step S33: placing one side of the metal bump on the slurry layer.

[0017] Preferably, in the process for manufacturing the wafer and metal bump bonding structure, step S4 specifically includes the following steps:

[0018] Transfer the metal bump and the wafer in step S3 into an oxygen-free oven, fill it with nitrogen, control the oxygen content to below 50 ppm, heat it to 150°C within 0.5h and keep it for 0.5h, then heat it to 220°C within 0.5h and keep it for 1h, then remove the support film and support frame at 220°C to obtain a bonding structure.

[0019] Preferably, the process for manufacturing the wafer and metal bump bonding structure, wherein step S3 comprises preparing a slurry layer on the wire bonding area of ​​the wafer and placing one side of the metal bump on the slurry layer, specifically comprises the following steps:

[0020] Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry;

[0021] Step S32: Covering the wire bonding area of ​​the wafer with a layer of wet slurry by screen printing or dispensing to form a slurry layer with a thickness of 10-200 μm;

[0022] Step S33, transferring the wafer coated with the slurry layer into an oxygen-free oven, filling it with nitrogen to control the oxygen content to be less than 50 ppm, heating it to 150° C. within 0.5 h and maintaining it for 1 h to obtain a semi-cured slurry layer;

[0023] Step S34: placing one side of the metal bump on the semi-cured slurry layer.

[0024] Preferably, the process for manufacturing the wafer and metal bump bonding structure, wherein step S3 is to form a layer of dry slurry film on the sintering surface of the metal bump, and place one side of the dry slurry film on the wire bonding area of ​​the wafer, specifically comprises the following steps:

[0025] Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry;

[0026] Step S32: transferring the wet slurry onto a support film through a screen printing process;

[0027] Step S33: transfer the wet slurry and the support film into an oven, heat it to 100-150°C over 0.5h, and maintain it for 1-3h to obtain a dry slurry film;

[0028] Step S34, laminating the dry slurry film on the side of the metal bump with the sintered surface by pressure transfer;

[0029] Step S35 , placing one side of the dry slurry film on the wire bonding area of ​​the wafer.

[0030] Preferably, the manufacturing process of the wafer and metal bump bonding structure is characterized in that the metal particles in step S31 are selected from silver particles or copper particles, the particle size of the metal particles is 50nm-100nm, the solvent is an alcohol or ether organic matter with a carbon chain of 4 to 8, and the sintering accelerator is a fatty amine with a decomposition temperature of about 150°C.

[0031] Preferably, in the process for manufacturing the wafer and metal bump bonding structure, step S4 specifically includes:

[0032] The metal bumps and the wafer transfer and pressure sintering mold of step S3 are transferred to a pressure sintering machine for sintering, and then the support film and support outer frame are removed to obtain a bonding structure. The sintering temperature is 230-280°C, the sintering time is 150-250 seconds, the sintering pressure is 8-20Mpa, and the temperature for removing the support film is 220°C.

[0033] Preferably, the manufacturing process of the wafer and metal bump bonding structure further includes a molding step after step S4, which is specifically: filling the gap between the wafer and the metal bump in the bonding structure with epoxy resin, and molding it with a transfer film to obtain a transfer-molded bonding structure, the molding temperature is 110-150°C, and the molding time is 50-150s.

[0034] A wafer and metal bump bonding structure is manufactured using a manufacturing process for the wafer and metal bump bonding structure.

[0035] The present invention has the following advantages:

[0036] (1) The manufacturing process of the wafer and metal bump bonding structure of the present invention solves the problems of metal layer damage and cracking during the wire bonding process caused by insufficient metal layer thickness in the chip wire bonding area during the manufacturing process of traditional semiconductor devices. By controlling the thickness of the metal bump to 50-300 microns, the metal bump is easy to bond with thick copper wire, thereby improving the current carrying capacity and heat dissipation capacity of the chip.

[0037] (2) In the manufacturing process of the wafer and metal bump bonding structure of the present invention, the metal layer is bonded to the chip lead area through a reliable sintering process, and epoxy resin sealant is filled in the gap between the metal layer and the wafer to protect the isolation area, interconnection layer and passivation layer of the chip, thereby improving the reliability of the chip in subsequent use.

[0038] (3) The manufacturing process of the wafer and metal bump bonding structure of the present invention realizes wafer-level coverage of the metal support film, and the thickness of the metal support film exceeds 100 microns, providing reliable support for subsequent thick copper wire bonding; greatly improving the current carrying capacity and heat dissipation capacity of the chip, especially the silicon carbide chip; the reliable sintering layer and epoxy resin sealant protect the isolation area, interconnection area and passivation area of ​​the wafer, thereby improving the reliability of the wafer.

[0039] (4) The manufacturing process of the wafer and metal bump bonding structure of the present invention is convenient and economical to operate; the electrode of the chip is led out by the copper sheet, and the gap between the wafer and the copper sheet is protected by the epoxy resin sealant. It can be directly applied to the PCB board, eliminating the need for packaging support, thereby improving the convenience and economy of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of Example 1 in which a support film is attached to one side of a metal sheet.

[0041] Figure 2 This is a schematic structural diagram of Example 1 in which a supporting outer frame is formed on one side of a metal sheet.

[0042] Figure 3 It is a schematic structural diagram of the slurry layer covering the wire bonding area of ​​the wafer in Example 1.

[0043] Figure 4 It is a schematic diagram of the structure in which the metal bumps are placed on the slurry layer in Example 1.

[0044] Figure 5 It is a structural schematic diagram of the wafer and metal bump bonding structure of Example 1.

[0045] Figure 6 It is a structural schematic diagram of the bonding structure of the transfer plastic seal in Example 1.

[0046] Figure 7 It is a schematic diagram of the structure of separating a single chip from the bonding structure in Example 1.

[0047] Figure 8 This is a schematic structural diagram of Example 2 in which a support film is attached to one side of a metal sheet.

[0048] Figure 9 It is a schematic structural diagram of the slurry layer covering the wire bonding area of ​​the wafer in Example 2.

[0049] Figure 10 It is a schematic diagram of the structure of Example 2 where the metal bump is placed on the semi-cured slurry layer.

[0050] Figure 11 It is a structural schematic diagram of the wafer and metal bump bonding structure of Example 2.

[0051] Figure 12 It is a structural schematic diagram of the bonding structure of the transfer plastic seal in Example 2.

[0052] Figure 13 It is a schematic diagram of the structure of separating a single chip from the bonding structure in Example 2.

[0053] Figure 14 It is a schematic structural diagram of Example 3 in which a support film is attached to one side of a metal sheet.

[0054] Figure 15 It is a schematic structural diagram of Example 3 in which a wet slurry is arranged on a supporting film.

[0055] Figure 16 Schematic diagram of the structure of the dry paste film bonded to the metal bump in Example 3.

[0056] Figure 17 It is a schematic structural diagram of the metal bump placed on the wire bonding area of ​​the wafer in Example 3.

[0057] Figure 18 It is a structural schematic diagram of the wafer and metal bump bonding structure of Example 3.

[0058] Figure 19 It is a structural schematic diagram of the bonding structure of the transfer plastic seal in Example 3.

[0059] Figure 20 It is a schematic diagram of the structure of separating a single chip from the bonding structure in Example 3.

[0060] Figure 21 It is a three-dimensional image of a metal bump with a support frame and a support film.

[0061] Figure 22 It is a three-dimensional schematic diagram of the bonding structure between the wafer and the metal bump. DETAILED DESCRIPTION

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and examples. Unless otherwise specified, the terms used herein should be understood according to the conventional usage of those skilled in the art.

[0063] As used in this article, a support film is attached to one side of the metal sheet, and the material of the support film is polyimide. The preferred material of the metal sheet is copper, and the brand can be C7025, EFTET64. In certain applications requiring a low thermal expansion coefficient, copper-molybdenum alloy or tungsten-copper alloy can be selected; the thickness of the metal sheet is preferably 50-300 microns, more preferably 100 microns, and more than 300 microns can also be used, but there will be greater residual stress; the sintered surface of the metal sheet can be silver-plated, and the thickness of the silver layer is 1-4 microns, preferably 3 microns.

[0064] Preferably, the wet slurry described in the present invention includes 60-80% metal particles, 20-30% solvent and 1-5% sintering accelerator, the metal particles are silver particles or copper particles, the average particle size of the metal particles is 50nm, and the maximum particle size does not exceed 100nm. The solvent is an alcohol or ether organic matter with a carbon chain of 4 to 8, and the sintering accelerator is a fatty amine with a decomposition temperature of about 150 degrees; the solvent specifically includes 60-70% isobutanol, 20-30% 2-pentanone and 5-10% propylene glycol methyl ether or isopropyl alcohol; the sintering accelerator can be an amine inorganic substance such as hexadecylamine, octadecylamine, and dodecylamine.

[0065] One side of the metal sheet is chemically etched to form a sintered surface, and a support frame is formed around the sintered surface. A plurality of spaced metal bumps are formed inside the support frame of the sintered surface. The support frame can be circular, square or other shapes that can play a supporting role.

[0066] Example 1

[0067] A process for manufacturing a wafer and metal bump bonding structure, the process comprising the following steps:

[0068] Step S1: providing a metal sheet 9 and a wafer 4. The metal sheet is made of copper, the grade is C7025, and the thickness of the metal sheet is 100 microns.

[0069] Step S2: Figure 1 Attach the support film 2 to one side of the metal sheet 9, as shown in FIG. Figure 2 , chemical etching is performed on the other side of the metal sheet 9 to form a sintered surface, a support outer frame 1 is formed on the periphery of the sintered surface, and a plurality of metal bumps 3 arranged at intervals are formed in the support outer frame 1 of the sintered surface. Silver is electroplated on the sintered surface of the metal sheet 9 to form a sintered surface with a silver layer. The thickness of the silver layer is 3 microns. After cleaning, the metal bumps 3 with the support outer frame 1 and the support film 2 are obtained. The three-dimensional image of the metal bumps 3 with the support outer frame 1 and the support film 2 is shown as follows Figure 21 , a plurality of metal bumps 3 arranged at intervals are formed in the supporting outer frame 1;

[0070] Step S3, preparing a slurry layer 5 on the wire bonding area of ​​the wafer 4, and placing one side of the metal bump 3 on the slurry layer 5;

[0071] Step S3 specifically includes the following steps:

[0072] Step S31, mixing 70% metal particles, 25% solvent, and 5% sintering accelerator by mass to obtain a wet slurry, wherein the metal particles are copper particles with a particle size of 50 nm, the solvent comprises 65% isobutanol, 25% 2-pentanone, and 10% propylene glycol methyl ether, and the sintering accelerator is hexadecylamine;

[0073] Step S32: Figure 3 , covering the wire bonding area of ​​the wafer 4 with a layer of wet slurry by screen printing or dispensing to form a slurry layer 5, the thickness of the slurry layer 5 being 100 microns;

[0074] Step S33, as Figure 4 , placing one side of the metal bump 3 on the slurry layer 5;

[0075] Step S4, transfer the metal bump 3 and the wafer 4 of step S3 into an oxygen-free oven, fill with nitrogen, control the oxygen content to below 50ppm, heat to 150℃ within 0.5h and keep for 0.5h, then heat to 220℃ within 0.5h and keep for 1h, then at 220℃, as shown in FIG. Figure 5, remove the support film 2 and the support frame 1 to obtain the wafer and metal bump bonding structure. The three-dimensional schematic diagram of the bonding structure is shown in FIG. Figure 22 ;

[0076] Step S5: Figure 6 , fill the gap between wafer 4 and the copper sheet in the bonding structure with epoxy resin powder, and then seal it with a transfer film at a temperature of 150°C for 100 seconds. Use a mechanical grinding process to remove excess plastic material and expose the copper sheet;

[0077] Step S6: Figure 7 The transferred plastic-sealed bonding structure is cut and separated into single chips by a wafer separator. The separated chips include a metal sheet 9, a wafer 4, a sintering slurry and an epoxy resin sealant 8. The metal sheet 9 is bonded to the lead bonding area of ​​the wafer 4 through the sintering slurry, and the epoxy resin sealant is filled in the gap between the wafer and the metal sheet to play a sealing role.

[0078] Example 2

[0079] A process for manufacturing a wafer and metal bump bonding structure, the process comprising the following steps:

[0080] Step S1: providing a metal sheet 9 and a wafer 4. The metal sheet is made of copper with a grade of C7025 and a thickness of 100 μm.

[0081] Step S2: Figure 8 Attach a support film 2 to one side of the metal sheet 9, chemically etch the other side of the metal sheet 9 to form a sintered surface, form a support outer frame 1 around the sintered surface, form a plurality of spaced metal bumps 3 within the support outer frame 1 of the sintered surface, electroplate silver on the sintered surface of the metal sheet 9 to form a sintered surface with a silver layer having a thickness of 3 microns, and then clean the surface to obtain the metal bumps 3 with the support outer frame 1 and the support film;

[0082] Step S3, preparing a slurry layer 5 on the wire bonding area of ​​the wafer, and placing one side of the metal bump 3 on the slurry layer 5;

[0083] Step S3 specifically includes the following steps:

[0084] Step S31, mixing 70% metal particles, 25% solvent, and 5% sintering accelerator by mass to obtain a wet slurry, wherein the metal particles are copper particles with a particle size of 50 nm, the solvent comprises 65% isobutanol, 25% 2-pentanone, and 10% propylene glycol methyl ether, and the sintering accelerator is hexadecylamine;

[0085] Step S32: Figure 9, covering the wire bonding area of ​​the wafer 4 with a layer of wet slurry by screen printing or dispensing to form a slurry layer 5 with a thickness of 100 microns;

[0086] Step S33, transferring the wafer 4 coated with the slurry layer 5 into an oxygen-free oven, filling it with nitrogen to control the oxygen content to be less than 50 ppm, heating it to 150° C. within 0.5 h and maintaining it for 1 h to obtain a semi-cured slurry layer 5;

[0087] Step S34: Figure 10 , placing one side of the metal bump 3 on the semi-cured slurry layer 5 .

[0088] Step S4: The metal bump 3 and the wafer 4 are transferred and the pressure sintering mold is transferred to a pressure sintering machine for sintering. Figure 11 , then remove the support film 2 and the support outer frame 1 to obtain a bonding structure, the sintering temperature is 250°C, the sintering time is 180 seconds, the sintering pressure is 12 MPa, and the temperature for removing the support film 2 and the support outer frame 1 is 220°C;

[0089] Step S5: Figure 12 , fill the gap between wafer 4 and the copper sheet in the bonding structure with epoxy resin powder, and then seal it with a transfer film at a temperature of 150°C for 100 seconds. Use a mechanical grinding process to remove excess plastic material and expose the copper sheet;

[0090] Step S6: Figure 13 The transferred plastic-sealed bonding structure is cut and separated into single chips by a wafer separator. The separated chip includes a metal sheet 9, a wafer 4, a sintering slurry and an epoxy resin sealant 8. The metal sheet is bonded to the wafer lead bonding area through the sintering slurry, and the epoxy resin sealant fills the gap between the wafer and the metal sheet to play a sealing role.

[0091] Example 3

[0092] A process for manufacturing a wafer and metal bump bonding structure, the process comprising the following steps:

[0093] Step S1: providing a metal sheet 9 and a wafer 4. The metal sheet is made of copper, the grade is C7025, and the thickness of the metal sheet is 100 microns.

[0094] Step S2: Figure 14Attach a support film 2 to one side of the metal sheet 9, chemically etch the other side of the metal sheet 9 to form a sintered surface, form a support outer frame 1 around the sintered surface, form a plurality of spaced metal bumps 3 within the support outer frame 1 of the sintered surface, electroplate silver on the sintered surface of the metal sheet 9 to form a sintered surface with a silver layer having a thickness of 3 microns, and then clean the surface to obtain the metal bumps 3 with the support outer frame 1 and the support film;

[0095] Step S3, forming a layer of dry paste film 6 on the sintering surface of the metal bump 3, and placing one side of the dry paste film 6 on the wire bonding area of ​​the wafer 4;

[0096] Step S3 specifically includes the following steps:

[0097] Step S31, mixing 70% metal particles, 25% solvent, and 5% sintering accelerator by mass to obtain a wet slurry, wherein the metal particles are copper particles with a particle size of 50 nm, the solvent comprises 65% isobutanol, 25% 2-pentanone, and 10% propylene glycol methyl ether, and the sintering accelerator is hexadecylamine;

[0098] Step S32: Figure 15 , transferring the wet slurry onto the support film 7 through a screen printing process;

[0099] Step S33: transfer the wet slurry and the support film 7 into an oven, heat it to 120° C. in 0.5 h, and maintain it for 1 h to obtain a dry slurry film 6;

[0100] Step S34: Figure 16 , attaching the dry slurry film 6 to the side of the metal bump 3 with the sintered surface by pressure transfer;

[0101] Step S35: Figure 17 , placing one side of the dry paste film 6 on the wire bonding area of ​​the wafer 3;

[0102] Step S4: The metal bump 3 and the wafer 4 of step S3 are transferred and the pressure sintering tool is transferred to a pressure sintering machine for sintering. The pressure sintering tool is a tray, such as Figure 18 , then remove the support film 2 and the support outer frame 1 to obtain a bonding structure, the sintering temperature is 250°C, the sintering time is 180 seconds, the sintering pressure is 12 MPa, and the temperature for removing the support film and the support outer frame is 220°C;

[0103] Step S5: Figure 19 , fill the gap between wafer 4 and the copper sheet in the bonding structure with epoxy resin powder, and then seal it with a transfer film at a temperature of 150°C for 100 seconds. Use a mechanical grinding process to remove excess plastic material and expose the copper sheet;

[0104] Step S6: Figure 20 The transferred plastic-sealed bonding structure is cut and separated into single chips by a wafer separator. The separated chips include metal bumps 3, wafers 4, sintering slurry and epoxy resin sealant 8. The metal sheet is bonded to the wafer lead bonding area through the sintering slurry, and the epoxy resin sealant fills the gap between the wafer and the metal sheet to play a sealing role.

[0105] Traditional method: The chip surface metal is aluminum silicon copper with a thickness of 5 microns, the bonding copper sheet thickness is 10 mm, and the package form is TO247.

[0106] Comparative Example 1

[0107] The patent application number is CN106170856A, and the patent name is "Patent application for a bracket and clip with a sinterable curable paste connected to a semiconductor element, a sintering paste, a production process and a use." The chip prepared by the disclosed method has an aluminum silicon copper surface metal with a thickness of 5 microns. The bonding copper sheet is oxygen-free copper. Due to process limitations, the thickness is selected to be 50 microns. The package form is TO247.

[0108] In Example 1-3, a finished chip with copper bumps (copper material grade: EFTET64, thickness: 100 μm) was obtained, the bonding copper sheet thickness was 10 mm, and the package form was TO247.

[0109] After packaging the chips produced by the manufacturing processes of Examples 1-3, as well as the chips produced by the conventional method and Comparative Example 1, the following tests were performed:

[0110] Thermal conductivity test method: Based on the International Electrotechnical Commission's test standard JESD51.

[0111] Reliability test method: Refer to the Automotive Electronics Council discrete device test standard AEC-Q101.

[0112] The test results are shown in Table 1.

[0113] Table 1

[0114]

[0115] It can be concluded from the test results in Table 1 that the current carrying capacity and heat dissipation capacity of the single chip obtained by Examples 1-3 of the present invention are superior to those of the traditional method and Comparative Example 1.

[0116] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A process for manufacturing a wafer and metal bump bonding structure, characterized in that: The process includes the following steps: Step S1, providing a metal sheet (9) and a wafer (4); Step S2, attaching a support film (2) to one side of the metal sheet (9), chemically etching the other side of the metal sheet (9) to form a sintered surface, forming a support outer frame (1) on the periphery of the sintered surface, forming a plurality of spaced metal bumps (3) within the support outer frame (1) of the sintered surface, and cleaning to obtain metal bumps (3) with the support outer frame (1) and the support film (2); Step S3, forming a slurry layer (5) on the wire bonding area of ​​the wafer (4), and placing one side of the metal bump (3) on the slurry layer (5); or forming a dry slurry film (6) on the sintered surface of the metal bump (3), and placing one side of the dry slurry film (6) on the wire bonding area of ​​the wafer (4); Step S4, sintering the metal bump (3) and the wafer (4) in step S3, and removing the support film and the support outer frame (1) to obtain a wafer and metal bump bonding structure; Step S5: cutting and separating the bonded structure in step S4 into individual chips.

2. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 1, wherein: In step S1, the material of the metal sheet (9) is selected from one of copper, copper-molybdenum alloy, and tungsten-copper alloy, and the thickness of the metal sheet (9) is 50-300 microns; step S2 also includes: electroplating silver on the sintered surface of the metal sheet (9) to form a sintered surface with a silver layer, and the thickness of the silver layer is 1-4 microns.

3. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 1, wherein: Step S3, wherein a slurry layer (5) is formed on the wire bonding area of ​​the wafer (4), and one side of the metal bump (3) is placed on the slurry layer (5), specifically comprising the following steps: Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry; Step S32: Covering the wire bonding area of ​​the wafer (4) with a layer of wet slurry by screen printing or dispensing to form a slurry layer (5) with a thickness of 10-200 microns; Step S33: placing one side of the metal bump (3) on the slurry layer (5).

4. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 3, wherein: Step S4 specifically includes the following steps: The metal bump (3) and the wafer (4) of step S3 are transferred to an oxygen-free oven, filled with nitrogen, and the oxygen content is controlled to be below 50 ppm. The temperature is raised to 150° C. within 0.5 h and maintained for 0.5 h, and then the temperature is raised to 220° C. within 0.5 h and maintained for 1 h. Thereafter, at a temperature of 220° C., the support film (2) and the support outer frame (1) are removed to obtain a wafer and metal bump bonding structure.

5. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 1, wherein: Step S3, wherein a slurry layer (5) is formed on the wire bonding area of ​​the wafer (4), and one side of the metal bump (3) is placed on the slurry layer (5), specifically comprising the following steps: Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry; Step S32: Covering the wire bonding area of ​​the wafer (4) with a layer of wet slurry by screen printing or dispensing to form a slurry layer (5) with a thickness of 10-200 microns; Step S33, transferring the wafer (4) coated with the slurry layer (5) into an oxygen-free oven, filling it with nitrogen, controlling the oxygen content to be less than 50 ppm, heating it to 150° C. within 0.5 h and maintaining it for 1 h, to obtain a semi-cured slurry layer (5); Step S34: placing one side of the metal bump (3) on the semi-cured slurry layer (5).

6. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 1, wherein: Step S3 comprises forming a layer of dry paste film (6) on the sintering surface of the metal bump (3), and placing one side of the dry paste film (6) on the wire bonding area of ​​the wafer (4). The steps specifically include the following steps: Step S31: mixing metal particles, a solvent, and a sintering accelerator to obtain a wet slurry; Step S32, transferring the wet slurry onto the support film (7) through a screen printing process; Step S33, transfer the wet slurry and the support film (7) into an oven, heat it to 100-150°C for 0.5h, maintain it for 1-3h, and obtain a dry slurry film (6); Step S34, laminating the dry slurry film (6) on the side of the metal bump (3) with the sintered surface by pressure transfer; Step S35: placing one side of the dry slurry film (6) on the wire bonding area of ​​the wafer (3).

7. The process for manufacturing a wafer-to-metal bump bonding structure according to any one of claims 3, 5, and 6, wherein: In step S31 , the metal particles are selected from silver particles or copper particles, the particle size of the metal particles is 50 nm-100 nm, the solvent is an alcohol or ether organic compound with a carbon chain of 4 to 8, and the sintering accelerator is a fatty amine.

8. The process for manufacturing a wafer-to-metal bump bonding structure according to any one of claims 5 and 6, wherein: Step S4 specifically includes: The metal bump (3) and the wafer (4) in step S3 are transferred and the pressure sintering mold is transferred to a pressure sintering machine for sintering, and then the support film (2) and the support outer frame (1) are removed to obtain a wafer and metal bump bonding structure. The sintering temperature is 230-280°C, the sintering time is 150-250 seconds, the sintering pressure is 8-20Mpa, and the temperature for removing the support film is 220°C.

9. The process for manufacturing a wafer-to-metal bump bonding structure according to claim 1, wherein: After step S4, a plastic sealing step is also included, which specifically includes: filling the gap between the wafer (4) and the metal bump (3) in the bonding structure with epoxy resin, and plastic sealing with a transfer film to obtain a transfer-molded bonding structure. The plastic sealing temperature is 110-150° C. and the plastic sealing time is 50-150 seconds.

10. A wafer and metal bump bonding structure, characterized in that: The invention is produced by the production process according to any one of claims 1 to 9.

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