Forming method of high-thermal-conductivity silicon nitride substrate

Abstract

The invention discloses a forming method of a high-thermal-conductivity silicon nitride substrate, and the forming process comprises the following steps: S1, burdening and ball milling: adding an organic monomer and a cross-linking agent into a solvent to prepare a premixed solution, and then mixing the premixed solution, a dispersing agent, silicon nitride and auxiliary ceramic powder for ball milling; and S2, adding a plasticizer to increase the flexibility of the silicon nitride sheet after tape casting. Then carrying out secondary ball milling, wherein the ball milling time is 4-30 hours; s3, vacuum defoaming: performing vacuum defoaming on the slurry obtained by secondary ball milling, and meanwhile, adding an initiator and stirring; s4, gel tape casting: carrying out tape casting operation on the slurry obtained by vacuum defoaming; and S5, drying the thin sheets, namely drying the thin sheets with certain strength and toughness after being cured for a certain time. According to the preparation method, a gel and tape casting combined technology is adopted, the advantages of two types of forming are integrated, the production cost is reduced, the environmental pollution is reduced, and the preparation of the high-performance silicon nitride ceramic substrate is realized.

Description

technical field [0001] The invention relates to the technical field of ceramic molding, in particular to a molding method of a silicon nitride substrate with high thermal conductivity. Background technique [0002] Silicon nitride ceramics have the advantages of high thermal conductivity, high dielectric strength, and matching the thermal expansion coefficient of Si, SiC, GaN, etc., and become ideal heat dissipation and packaging materials for a new generation of large-scale integrated circuits, semiconductor module circuits, and high-power devices. . [0003] At present, the main method for preparing silicon nitride ceramic substrates is tape casting, and most of them are organic solvent tape casting. Although after decades of development, tape casting technology has been applied to industrial production, there are still many problems, such as the use of certain toxic organic solvents (benzene, toluene, xylene, acetone, methyl ethyl ketone, etc.) are more toxic, High prod...

AI Technical Summary

Problems solved by technology

Although after decades of development, tape casting technology has been applied to industrial production, there are still many problems, such as the use of certain toxic organic solvents (benzene, toluene, xylene, acetone, methyl ethyl ketone, etc.) are more toxic, High production cost, unfriendly to the environment and harmful to health; the introduction of a large amount of organic matter in the slurry leads to low density of the green body, and the green body is easy to crack and deform during the debinding process; the ceramic powder settles during the drying process, and the upper and lower surfaces of the green body A density gradient is formed, which can lead to cracks, pits, peeling, etc. on the upper surface