Application of ultrasonic assisted soldering method to hard-to-solder material

In this study, Pb-free solders were bonded to soda-lime glass and fused quartz plates using the ultrasonic assisted soldering (UAS) method. The solder–glass interfaces were observed and analyzed to clarify the effect of the elements in the solder and glass bonding behavior. As a result, the Sn–Zn solder was bonded to glass without the intermetallic compound (IMC) layer. However, the Sn–Ag–Cu solder was not able to bond to glass even though ultrasonication was performed during the soldering process. Chemical shifts for Zn 2p and O 1s spectra were observed at the interface by X-ray photoelectron spectroscopy (XPS) analysis, which is attributed to the chemical bonding between the substrates and elements in solder alloy. In conclusion, O in the substrate and Zn in the solder were important to form the bond between the glass and solder.