Dry (fluxless) thermal soldering processes

Summary form only given. With the shrinking sizes of all electronic components and bonding pads, the very fast growth of surface-mount technology (SMT), and the greater demand for flip-chip device bonding, both fluxing and cleaning steps are becoming more difficult to perform effectively. A dry fluxless soldering process can avoid these limitations and provide a practical solution especially attractive to SMT. An approach for dry fluxless thermal soldering using conventional solders and soldering temperatures is being developed. The process is, however, not limited to specific solder joints and can be extended to different solder systems and different metallurgies. The basic process and the results of applying it to dry soldering of SMT parts with 60/40 solder at 240 degrees C are presented.<>