Glass to Glass Joint by Low Temperature Soldering Using Localized Induction Heating Process

Thermally sensitive devices, such as micro- LEDs, require low-temperature bonding to prevent thermal damage. Conventional reflow processes pose overheating risks due to uniform heat input. This study evaluates induction heating as a localized bonding technique, utilizing a magnetic Ni sheet inserted as a heat source for glass-glass joints. Compared to samples without a Ni insert, temperature measurements showed that configurations with the inserted Ni sheet reached the melting point of the Sn-Bi solder in just 2 s, with the glass chip temperature maintained at 90°C. Microstructural analysis using SEM and SAT confirmed the bonding quality was satisfactory. The results demonstrate that inserting a magnetic material enables rapid solder joint formation while minimizing thermal impact on substrates and chips. This method shows significant promise for applications involving thermally sensitive devices.