Electronic component packing density is increasing rapidly because of requirements for greater reliability, greater resistance to vibration and shorter signal path. SMT techniques, representing state-of-the-art, require advanced soldering technology including dual-wave, IR, ultrasonic and blanketed vapor phase soldering. The sheer number of solder connections in DAIC/PC will require new extremely high-yield, high-reliability solder attachment equipment. A solder joint connects a component to a PC board both electrically and mechanically. Therefore, solder integrity is a critical factor in military equipment reliability. In this proposal unique gas curtain soldering equipment is described that produces strong, reliable, reproducible solder bonds without the use of chemical fluxes. Elimination of fluxes and flux removal will be a major advance because fluxes are abietic acids that can later cause reliability problems in SMT and DAIC/PC assemblies. Increased throughput is another major goal of the program. An industry survey of 720 companies has been undertaken with results showing overriding interest and need for equipment of the type proposed.
