Preparation method of high-thermal-conductivity net-size silicon nitride ceramic substrate

Abstract

The invention relates to a preparation method of a high-thermal-conductivity net-size silicon nitride ceramic substrate, which comprises the following steps of (1) mixing at least one of silicon nitride powder and silicon powder as original powder, a sintering aid, a dispersing agent, a defoaming agent, a binder and a plasticizer in a protective atmosphere, and performing vacuum degassing to obtain mixed slurry, (2) carrying out tape casting and drying in a nitrogen atmosphere to obtain a first biscuit, (3) carrying out shaping pretreatment on the obtained first biscuit to obtain a second biscuit, (4) debonding the obtained second biscuit in a nitrogen atmosphere with micro-positive pressure at 500-900 DEG C to obtain a third biscuit, and (5) placing the obtained third biscuit in a nitrogen atmosphere, and carrying out air pressure sintering at 1800-2000 DEG C to obtain the high-thermal-conductivity net-size silicon nitride ceramic substrate.

Description

technical field [0001] The invention relates to a method for preparing a silicon nitride ceramic substrate with high thermal conductivity and net size, and belongs to the field of ceramic material preparation. Background technique [0002] In recent years, semiconductor devices have developed rapidly along the direction of high power, high frequency, and integration. The heat generated by the operation of semiconductor devices is the key factor causing the failure of semiconductor devices, and the thermal conductivity of the insulating substrate is the key to affecting the overall heat dissipation of semiconductor devices. In addition, such as in the fields of electric vehicles and high-speed rail, semiconductor devices often face complex mechanical environments such as bumps and vibrations during use, which imposes strict requirements on the mechanical reliability of the materials used. [0003] High thermal conductivity silicon nitride (Si 3 N 4 ) Ceramics have excellen...

AI Technical Summary

Problems solved by technology

Among them, due to the non-uniformity of powder flow and the process characteristics of mechanical pressing, the substrates formed by dry pressing often have difficulties such as direct preparation of ceramic substrates with a thickness of less than 0.5mm, the thickness cannot be accurately controlled, and the thickness is uneven. Hence the need for subsequent machining

The rolling film forming process is complicated, and it is necessary to repeatedly roll the film to eliminate the uneven thickness caused by the limitations of the process itself and the bumps caused by the agglomeration of raw materials, resulting in the prepared substrates prone to blistering and uneven surfaces. Machining can meet the subsequent copper clad process requirements

In contrast, the tape casting process has high production efficiency, low cost, can realize full automation, and is convenient for continuous batch production. It is the most promising and potential technology for ceramic substrate forming, but there are also tape casting The film is prone to blistering, cracking, deformation, uneven thickness, etc., resulting in problems such as low yield, low flatness, uneven thickness, and the need for subsequent machining

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