Induction of tin pest transformation in solder joints in ceramic packages of sub-THz scanner

Tin pest (transformation of β-tin into α-tin) may cause deterioration of the mechanical properties of joints or even their complete disintegration. The method of simulation of α-tin growth can be essential in diagnostic testing of the susceptibility of different tin-rich solder alloys to tin pest. The method described in this work ensures rapid diagnosis. Especially the devices working at sub-zero temperatures, where ceramic substrate or packages are involved could be prone to the risk of damage because of the tin pest in solder joints. The inoculation using different agents with cubic structure with simultaneous surface pre-treatment with HCl and compression of 30kN ensures an efficient way to induce growth in a time shorter than 48 hours. The influences of the inoculation depth and additional strains presence have been also proved.