Home ›

GPLF Optimization Study

Idea/Definition Information
Background: 

The introduction of RoHS and similar environmental legislation has driven the need to transition PCB products to be manufactured with Pb Free solder. While simpler designs can be produced with alternative Tin Solder Copper solder with little difficult, manufacturing larger and more complicated products, with high reliability demands, presents significant challenges, specifically in minimizing thermal stresses on certain components through the SMT solder reflow process. In order to overcomethese issues, process optimization is essential.

Problem: 

Assembling  large and densely populated printed circuit boards while ensuring that the components on the boards are not exposed to reflow temperatures that exceed supplier's and industry standard regulations is a demanding task for PCB manufacturers. This project characterizes the process window the solder reflow process and conducts reliability trials on test vehicles/components produced at the limits of these optimized processes. 

Approach: 

A preliminary set of trials were conducted to determine the peak temperature variation between different types of components on sample boards when solder using a variety of different sets of reflow parameters. Several optmized profiles that minimized both temperature variation and max peak temperature on the hottest components were developed and these profiles were used to produce over 100 test vehicles. Post assembly analysis was conducted on sample TVs and the rest were submitted for accelerated temperature cycling. Daisy chains within the components were continuously monitored and Weibull analysis / failure anaysis were conducted on failed parts.