CN-121075726-B - Low-temperature curing slurry for enhancing temperature cycle resistance and preparation method thereof

CN121075726BCN 121075726 BCN121075726 BCN 121075726BCN-121075726-B

Abstract

The invention discloses a low-temperature curing slurry for enhancing temperature cycle resistance and a preparation method thereof, and relates to the field of chip packaging, wherein the low-temperature curing slurry comprises, by mass, 1-20% of thermoplastic resin particles, 0.1-5.0% of thermosetting resin, 0.1-1.5% of solvent and the balance of silver powder, the silver powder comprises, by mass, 10-45% of spherical nano silver particles a, 1-5% of spherical nano silver particles b and the balance of micron silver flakes, the particle size of the micron silver flakes is 1-10 mu m, the particle size of the spherical nano silver particles a is 50-100nm, the particle size of the spherical nano silver particles b is 5-50nm, and the particle size of the thermoplastic resin particles is 1-15 mu m. According to the invention, the slurry prepared from the components such as the thermoplastic resin particles, the silver powder and the like is used, when the joint structure formed by solidifying the slurry is subjected to temperature circulation, the thermoplastic resin particles can be melted at high temperature and dynamically fill the pores among the silver powder particles, so that migration paths of silver atoms are blocked, metal grain growth caused by temperature fluctuation is inhibited, and internal stress generated by grain coarsening is reduced.

Inventors

JIANG LIANG
YANG FAN
WU WEIZHEN
LAI YUPING

Assignees

深圳芯源新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20251107

Claims (8)

1. A preparation method of low-temperature curing slurry for enhancing temperature cycle resistance is characterized by comprising, by mass, 1-20% of thermoplastic resin particles, 0.1-5.0% of thermosetting resin, 0.1-1.5% of solvent and the balance of silver powder, wherein the preparation method of the low-temperature curing slurry for enhancing temperature cycle resistance comprises the following steps: step S1, mixing silver powder comprising micron silver flakes, spherical nano silver particles a, spherical nano silver particles b and thermoplastic resin particles, wherein the silver powder comprises, by mass, 10-45% of spherical nano silver particles a, 1-5% of spherical nano silver particles b and the rest micron silver flakes, the particle size of the micron silver flakes is 1-10 mu m, the particle size of the spherical nano silver particles a is 50-100nm, the particle size of the spherical nano silver particles b is 5-50nm, and the particle size of the thermoplastic resin particles is 1-15 mu m; s2, performing surface active treatment on the mixed powder to obtain active powder; S3, mixing the active powder, the aliphatic hydrocarbon solvent, the monomer mixture and the AIBN to obtain a mixed solution, filtering the mixed solution to obtain a solid product, and washing and drying the solid product through ethanol to obtain composite powder; S4, mixing the composite powder with thermosetting resin and a solvent, and obtaining low-temperature curing slurry after mixing; the step S2 specifically includes the following steps: Step S21, placing the mixed powder on a porous plate in a plasma reactor, vacuumizing a plasma reactor chamber to below 10Pa, allowing a first gas to pass through the porous plate with the pore diameter of 0.5-5 mu m to enable the mixed powder to tumble, and introducing oxygen to perform preliminary treatment on the mixed powder to obtain the preliminary powder, wherein in the step S21, the preliminary treatment time is 5-15min, the working gas pressure of the plasma reactor chamber is 20-100Pa, the power is 100-200W, the flow rate of the oxygen is 50-200sccm, the flow rate of the first gas is 500-2000sccm, and the first gas is argon; and step S22, maintaining the state of the step S21, and enabling a second gas to pass through holes of a porous plate and the mixed powder to perform secondary treatment, wherein the active powder is obtained after the secondary treatment is completed, the secondary treatment time is 20-40min, the temperature of a plasma reactor chamber is 70-90 ℃, the working pressure is 50-200Pa, the flow rate of the second gas is 100-500sccm, the second gas is the mixed gas of the vaporizing VTES and the argon, and the volume flow rate ratio of the vaporizing VTES to the argon is 1 (1-5).
2. The method for producing a low-temperature-curable slurry having enhanced temperature cycle resistance according to claim 1, wherein, The mixed solution is obtained according to the following steps: Step S31, primarily mixing the active powder, the aliphatic hydrocarbon solvent and the monomer mixture to obtain a primary mixture; step S32, mixing the primary mixture with AIBN again to obtain a mixed solution.
3. The method for producing a low-temperature-curable slurry having enhanced temperature cycle resistance according to claim 2, wherein, In the step S31, the rotating speed of the primary mixing is 100-300rpm, the time is 30-60, the mass ratio of the monomer mixture to the aliphatic hydrocarbon solvent to the active powder is (5-15): (30-60): 100, the aliphatic hydrocarbon solvent is any one of n-hexane, n-heptane and isooctane, the monomer mixture is a mixture of HEMA and EGDMA, wherein the mass ratio of HEMA to EGDMA is (95-98): (2-5); In the step S32, the addition amount of AIBN is 0.5-1.0% of the total mass of the monomer mixture in the step S31, the remixing temperature is 70-80 ℃, the rotating speed is 50-150rpm, the time is 6-12h, and the heating rate is 1-3 ℃ per minute.
4. The method for producing a low-temperature curing paste for enhancing temperature cycle resistance according to claim 1, wherein the thermoplastic resin particles are any one of polyvinyl chloride, polyvinyl acetate, polyamide, polymethyl methacrylate, and natural rubber.
5. The method for preparing a low-temperature curing paste for enhancing temperature cycle resistance according to claim 1, wherein the thermosetting resin is any one or more of epoxy resin, polyurethane resin, vinyl acid resin, silicone resin.
6. The method for preparing a low-temperature curing paste for enhancing temperature cycle resistance according to claim 1, wherein the solvent is any one of an alcohol-based solvent, an acetic acid-based solvent, a hydrocarbon-based solvent and a mixture of the three.
7. The method for preparing the low-temperature curing paste for enhancing the temperature cycle resistance according to claim 1, wherein the low-temperature curing paste further comprises less than 1.5% of curing agent and less than 0.5% of curing accelerator in percentage by mass, wherein the curing agent is any one or more of dicyandiamide, anhydride and phenol resin, and the curing accelerator is any one or more of imidazole-based curing accelerator, amine-based curing accelerator, diazabicyclo-based curing accelerator and urea-based curing accelerator.
8. A low temperature curing paste for enhancing temperature cycle resistance, characterized in that the low temperature curing paste is obtained by the preparation method according to claims 1 to 7.

Description

Low-temperature curing slurry for enhancing temperature cycle resistance and preparation method thereof Technical Field The invention relates to the field of chip packaging, in particular to low-temperature curing slurry for enhancing temperature cycle resistance and a preparation method thereof. Background As the chip is miniaturized, the chip integration level and the power density are gradually increased, so that the chip operation temperature is higher and higher, and the high Wen Fuyi capability of the packaging structure is also more and more important. The traditional packaging conductive glue is low in melting point, is easy to fail at high temperature to cause damage to a chip, cannot be applied to high-density packaging, is excellent in electric conduction and heat conduction performance, is high in melting point, is high in price and is difficult to apply to a large scale in production, the melting point of metal silver is 961 ℃, the electric conduction and heat conduction performance is excellent, nano-sized silver particles have the characteristics of low-temperature sintering and high-temperature service under the effect of size effect, and has a great application prospect in the field of high-power electronic device packaging. The existing silver paste in the market mainly comprises silver powder, a solvent and thermosetting resin, wherein the silver powder is used for conducting electricity and heat and performing interface sintering, the thermosetting resin is used for uniformly dispersing the silver powder to prevent precipitation and accumulation of the silver powder, meanwhile, interface auxiliary bonding is realized, the solvent is used for adjusting paste viscosity to improve paste operability, however, when temperature fluctuation occurs in the service process of the interconnection joint structure formed by the conductive paste, large stress is generated due to metal grain growth caused by high temperature, and finally, the joint and a substrate are separated. Therefore, a low-temperature curing slurry for enhancing temperature cycle resistance and a preparation method thereof are provided for solving the problem that a joint structure causes metal grain growth along with temperature fluctuation and generates larger stress. Disclosure of Invention The invention aims to provide low-temperature curing slurry for enhancing temperature cycle resistance and a preparation method thereof, which solve the problem that a joint structure causes metal grain growth along with temperature fluctuation and generates larger stress. To achieve the purpose, the invention adopts the following technical scheme: The low-temperature curing slurry for enhancing the temperature cycle resistance comprises, by mass, 1-20% of thermoplastic resin particles, 0.1-5.0% of thermosetting resin, 0.1-1.5% of solvent and the balance of silver powder; the silver powder comprises, by mass, 10-45% of spherical nano silver particles a, 1-5% of spherical nano silver particles b and the rest of micron silver flakes; The particle size of the micron silver flake is 1-10 mu m, the particle size of the spherical nano silver particle a is 50-100nm, the particle size of the spherical nano silver particle b is 5-50nm, and the particle size of the thermoplastic resin particle is 1-15 mu m. The thermoplastic resin particles are any one of polyvinyl chloride, polyvinyl acetate, polyamide, polymethyl methacrylate and natural rubber. The thermosetting resin is any one or more of epoxy resin, polyurethane resin, vinyl acid resin and silicone resin. The solvent is any one of alcohol-based solvent, acetic acid solvent, hydrocarbon solvent and mixture of the three. The low-temperature curing slurry also comprises less than 1.5% of curing agent and less than 0.5% of curing accelerator according to mass percent, wherein the curing agent is any one or more of dicyandiamide, anhydride and phenol resin, and the curing accelerator is any one or more of imidazole-based curing accelerator, amine-based curing accelerator, diazabicyclo-based curing accelerator and urea-based curing accelerator. A method for preparing a low-temperature-curable slurry having enhanced temperature cycle resistance, the method being applied to the low-temperature-curable slurry as described above, the method comprising the steps of: Step S1, mixing silver powder comprising micron silver flakes, spherical nano silver particles a and spherical nano silver particles b with thermoplastic resin particles, and obtaining mixed powder after the mixing is completed; s2, performing surface active treatment on the mixed powder to obtain active powder; S3, mixing the active powder, the aliphatic hydrocarbon solvent, the monomer mixture and the AIBN to obtain a mixed solution, filtering the mixed solution to obtain a solid product, and washing and drying the solid product through ethanol to obtain composite powder; and S4, mixing the composite powder with thermosetting resin and a sol