Low temperature bonding mechanism of porous Si3N4 ceramics by Sn9Zn solder in ultrasonic-assisted soldering

Porous Si3N4 ceramics are widely used materials but very difficult to join. In this work, we successfully ultrasonically soldered porous Si3N4 ceramic rapidly at a low temperature of 230 degrees C. The wetting and bonding mechanism at the ceramic/solder interface was studied. Results showed that the solder rapidly infiltrated the micro-channels of the ceramic during soldering, and high ultrasonic power contributed the sonocapillary distance. Zn and O acted as the main bonding elements. Bonding was realized by the formation of nanocrystalline and amorphous ZnOx region at the wetting interface. Rapid bonding was achieved due to the high liquid velocity, high temperature, and high pressure caused by the collapse of the cavitation bubbles.

Automated summary

In this study, we achieved rapid soldering of porous Si3N4 ceramics at a low temperature using ultrasound. The solder rapidly infiltrated the micro-channels of the ceramic and bonding was realized by the formation of nanocrystalline and amorphous ZnOx region.