Eutectic welding method for box dam on silicon nitride ceramic base plate

Abstract

The invention discloses a eutectic welding method for a box dam on a silicon nitride ceramic base plate. The method includes the following steps that step 1, a metal circuit coating is printed on thesilicon nitride ceramic base plate through a thick-film printing technology, and the shape of the metal circuit coating fits the shape of the box dam required to be welded onto silicon nitride ceramic; step 2, the silicon nitride ceramic base plate and the box dam are placed into a eutectic welding device; step 3, alloy solder is placed on the metal circuit coating of the silicon nitride ceramic base plate, then the box dam is printed or placed onto the silicon nitride ceramic base plate across the alloy solder, and the box dam is corresponding with the metal circuit coating in shape; step 4,the eutectic welding device is started for welding, and the welding temperature ranges from 150 DEG C to 1,500 DEG C; and step 5, welding is completed. According to the method, box dam welding of thesilicon nitride ceramic is performed in the eutectic welding manner, and compared with the prior art which adopts magnetron sputtering, the method is more convenient to operate and lower in cost.

Description

technical field [0001] The invention relates to the technical field of glass packaging, in particular to a method for eutectic welding of dams on silicon nitride ceramic substrates. Background technique [0002] Si 3 N 4 It has three crystal structures, namely α phase, β phase and γ phase (among which α and β phase are the most common forms), all of which are hexagonal structures, and its powder and substrate are off-white. Si 3 N 4 The elastic modulus of the ceramic substrate is 320GPa, the bending strength is 920MPa, the thermal expansion coefficient is only 3.2×10 6 / ℃, and the dielectric constant is 9.4. It has the advantages of high hardness, high strength, small thermal expansion coefficient and high corrosion resistance. Since Si 3 N 4 The ceramic crystal structure is complex and has a large scattering of phonons, so early studies believed that its thermal conductivity is low, such as Si 3 N 4 The thermal conductivity of bearing balls, structural parts and oth...

AI Technical Summary

Problems solved by technology

However, its preparation process is complicated, its cost is high, and its thermal conductivity is low. It is mainly suitable for applications in fields that require high strength but low heat dissipation requirements.

[0007] When the silicon nitride ceramic substrate is used as the LED substrate, the dam needs to be welded. The existing welding is performed by magnetron sputtering, which is relatively complicated and costly.

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