Evaluating vapor phase soldering for fine pitch BGA

Surface mounted components are considered fine pitch if lead pitches are equal or lower than 0.65 mm (25 mils). Fine pitch Ball Grid Array (BGA) Integrated Circuits (IC-s) require special considerations for design, assembly and failure analysis. Design for Manufacturing (DfM) is a key aspect in the PCB design process. As for soldering, Vapor Phase Soldering (VPS) is an emerging reflow method for fine pitch surface mounted components. Thermal profiling investigation is also important during the process of VPS. The Department of Electronics Technology of BME has been carrying out research and prototyping with the use of an Asscon Quicky 450 type Vapor Phase Soldering system and a locally developed experimental VPS system. The application of two systems makes it possible to use parallel experiments with two different Galden liquids with distinct boiling points. The experimental VPS system is very flexible considering heat profiling and temperature control. In this paper an experiment is presented, where a custom set of test boards and 0.65 mm pitch BGA were used and a set of thermal profiles were measured to evaluate VPS reflow soldering for fine pitch surface mounted components.