Precision high temperature lead-free solder interconnections by means of high-energy droplet deposition techniques

This paper presents a number of numerical models that illustrate the experimental details of the key physical phenomena affecting the operation of novel materials deposition processes for electronics assembly. These processes include both laser and electric arc based droplet deposition processes. These are being developed in the electronics industry to allow the use of new lead-free alloys as replacements for high temperature lead based alloys, such as Sn5Pb95. The paper presents models of physical processes with respect to the desired process metrics of droplet size and deposition accuracy and reviews the potential limiting product - process interactions such as excessive thermal excursions and their effects on the target materials being joined.