Towards a standard for differential scanning calorimetry measurement of solder paste products

With the continuing technological advancement in circuit board and component design there is a need to understand the overall soldering process including solder materials, printing applications and reflow processes. This is due to increased component packing density with the subsequent decrease in feature sizes and increases in joint counts per assembly. This places greater emphasis on the design of joint formation processes in order to manage, or predict, the outcome of the inherent process-materials interactions which determine the quality of joint formed. Differential Scanning Calorimetry (DSC) offers a potential avenue to describe, quantitatively, the interactions of joining media with joining processes and study the behaviour of solder pastes. This paper presents the results of a series of trials with DSC analysis of solder paste materials in order to determine the suitability of the DSC technique as a means to characterise these materials with respect to intended manufacturing processes. The results indicate that there is a necessity for standardised DSC testing methodologies which control key test variables including the mass of the solder sample