| CPC C04B 37/003 (2013.01) [C04B 35/584 (2013.01); C04B 35/638 (2013.01); C04B 35/64 (2013.01); C04B 2235/428 (2013.01); C04B 2235/6025 (2013.01); C04B 2235/6567 (2013.01); C04B 2235/6581 (2013.01); C04B 2235/6582 (2013.01); C04B 2237/08 (2013.01); C04B 2237/368 (2013.01)] | 14 Claims |

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1. A batch sintering method for making a high-property silicon nitride ceramic substrate, comprising the following steps:
(1) stacking silicon nitride ceramic substrate green bodies, putting the silicon nitride ceramic substrate green bodies into a boron nitride crucible, and applying a layer of boron nitride powder between adjacent silicon nitride ceramic substrate green bodies;
(2) performing step-by-step vacuumization, and then debinding in a nitrogen atmosphere or a reducing atmosphere at 500° C. to 900° C.; wherein the step-by-step vacuumization is performed in at least two steps or at least three steps; if vacuumization is performed in the at least two steps, parameters of the step-by-step vacuumization include: a first step of 20 to 30 minutes of vacuumization for making a vacuum degree reach 20 kPa to 30 kPa, and a second of 10 to 20 minutes of vacuumization for making a vacuum degree less than 10 Pa; or if vacuumization is performed in the at least three steps, parameters of the step-by-step vacuumization include: a first step of 10 to 15 minutes of vacuumization for making a vacuum degree reach 60 kPa to 80 kPa, a second step of 10 to 15 minutes of vacuumization for making a vacuum degree reach 10 kPa to 30 kPa, and a third step of 10 to 15 minutes of vacuumization for making a vacuum degree less than 10 Pa; and then
(3) performing gas pressure sintering in a nitrogen atmosphere at 1800° C. to 2000° C., thereby completing a batch preparation of the high-property silicon nitride ceramic substrate.
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