The effect of surface treatment using ceramic powder on adhesion properties in high reliability pressure sensor

An increasing number of pressure sensors are built in Si MEMS bridge structure using resistance devices. Recently, due to advance in autonomous driving and vehicles, numerous research in stability and sensitivity of pressure sensors have been conducted. In this research, metal diaphragm surface treatment characteristics, when MEMS devices are adhesived to the structure, to which pressure is transferred from the metal diaphragm, were studied. For surface structure shape, sand blasting process was used for the surface treatment. It is known that during the sand blasting process, adhesive strength increases with increases in penetration of the adhesive material and in surface roughness which results from an increase in powder sizes. However, based on the result obtained from this experiment, the uniformity of roughness determines adhesion, after a certain level of roughness is reached. Past a particular size of a SiC ceramic powder, adhesion shows decreasing trend because the thickness of adhesive materials decreases due to local variation in the surface. We could verify that in order to optimize the adhesion of the adhesive material from the sand blasting treatment, SiC ceramic powder sizes and treatment pressure need to be optimized.