Sintering mechanism of ceramic and metal substrate
The distribution of a large area of metal graphics is the final important factor warp of the single metal porcelain deformation is most serious, the reason is because the metal contraction stress is greater than the ceramic shrinkage stress, resulting from the direction of bending metal porcelain. The mechanism is in the process of sintering, metal and glass ceramic substrate inside the glass phase in mutual penetration, the combination of the interface relative to the internal contains more glass phase, the glass phase is greater than the shrinkage shrinkage grain ceramic matrix, so the direction of bending metal to ceramic.
The metal porcelain face sintering, the roughness increased, this is because the porcelain in high temperature softening, the arched upward bending of the trend of decline in the porcelain under its own gravity; and the metal layer in the process of contracting, at the same time by following molybdenum plate friction, offset a part of the uneven shrinkage stress.
When the porcelain pieces have a more serious warping, the surface of the surface pressure to smooth and flat plate of molybdenum, under the conditions of sintering temperature to re burn once, can improve the flatness, to meet the use requirements. Therefore, proper control of green tape shrinkage rate match, sintering control system, reasonable design of metal graphic distribution, making it as uniform as possible, with the leveling technology properly, can ensure the porcelain warpage is less than 1 per thousand.
For the electric vacuum device case for PGA type plug, the requirements of the metal parts and ceramics with a high bonding strength, to meet the use requirements. And the intensity of the metal directly affects the sealing strength and air tightness, as the main cause of the failure of the seal, it is based on the strength of the seal to determine whether the strength of the metal is qualified.