Electronics assembly, rework, and reliability evaluation using lead-free soldering materials, halogen-free laminate materials, and surface finishes with nanomaterials.

摘要

For the past decade, there has been a global effort in the electronics industry to initiate a move towards using lead-free materials for the production of printed circuit boards. However, there are numerous technical and economic challenges, such as long term reliability and rework capability, that remain to hinder the universal implementation of lead-free materials. Consequently, many electronics products are still currently manufactured and assembled using materials containing lead.;This research included an evaluation of the assembly of test vehicles using various lead-free, halogen-free and nano-materials. The test vehicles included a variety of both surface mount and through hole components. The lead-free materials evaluated during the assembly included various component finishes, four board surface finishes, three through hole component solders, and four surface mount component solder pastes. In addition, a halogen-free laminate material and a nano-material based surface finish were also included. The results of the lead-free assemblies were compared against baseline data obtained by assembling test vehicles with tin/lead materials. These test vehicles were then subject to thermal cycling and internal stress testing to evaluate the long term reliability of these assemblies. In addition, research was conducted on the effectiveness of lead-free materials for rework capability. Various statistical tools were used to compare the results including Design of Experiments, Analysis of Variance, Pareto Charts, Main Effects Plots, and Interaction Plots.