Characterisation of 980nm Pump Laser Solder Joint Integrity Using Heat Pump Tests

We describe a means of assessing the quality of the solder joints of chip-on-carrier (CoC), housing and heat pump assembly of 980 nm pump laser modules. Organic and oxide contamination on piece parts will lead to poor solder flow which may impact the thermal performance of the heat pump (or thermal electric cooler). In this paper, heat pump tests have been conducted for the evaluation of solder joint integrity using fluxless vacuum soldering. Structured experimental design was used to determine the critical vacuum soldering parameters .The results indicate that the condition of the Sn/Pb solder perform is the most critical parameter followed by the peak reflow temperature in terms of the heat pump performance. A technique was also developed for quantifying the visual observation criteria. The results show the peak reflow temperature as the most critical parameter that impacts the flow of solder.