Thermal management of heat sensitive components in lead-free assembly and rework process

In adapting to lead-free processing there are a number of challenges that electronics manufacturers face. The two main concerns faced are related to the alternative Pb-free solder alloys and the effect of higher temperatures on heat-sensitive components and the PCB itself. This thesis concentrates on the issues related to the heat-sensitive components in Pb-free assembly and rework processes.; In this thesis, different challenges related to heat-sensitive components in lead-free assembly and rework are discussed in detail. An effort is made to solve the issues in the form of a novel thermal management approach that uses cooling/thermal caps. Different types of cooling caps and their respective applications in Pb-free assembly and rework processes are discussed in detail.; Challenges of processing heat-sensitive components, along with the design of appropriate cooling caps, are discussed via different case studies. The studies are divided into four parts: challenges in the process, process details, cooling cap configurations used, and results. Performance of various cooling cap designs is analyzed with according to different inputs, such as assembly and rework profiles, varying component sizes, and different test vehicles.; This technology is shown to facilitate the assembly and rework of legacy and other heat-sensitive components in Pb-free processing. Results indicate that, with the use of these cooling caps, the thermally sensitive components along with the PCB substrates can be protected from the harsh Pb-free assembly and reflow environments.; The future scope and recommendations that have been identified based on the in-house and ongoing beta testing, are also summarized.