Switching solder paste when you’re getting the yields you want may sound like throwing out the solder paste with the circuit board, but listen again. Advances in paste technology necessitate continual evaluation. Whether you need to tackle lead-free, head-and-pillow or another reflow issue, the surge in materials coming to market warrants an intermittent process to evaluate and qualify these new solder pastes.
But, what is an appropriate level of testing considering time and budgetary constraints? World-class suppliers perform rigorous laboratory testing. These tests, performed by reputable organizations, are solid. Is there any merit in replicating them? Generally speaking, no.
Today, it’s more commonly accepted to buy into the test results that are done by the paste manufacturer lab. However, you may want to consider conducting your own performance tests or process tests. These are tests that evaluate how each new paste performs during your specific process. They make look at printability, shelf life, tack and more.
Then, consider doing a design of experiments (DOE) such as the 27-board challenge developed by Cookson Electronics. It’s an economical and practical test that examines several parameters with a small sample size.
Keeping apprised of new developments in technology helps to ensure you are always operating at peak performance, so making any number of switches will always sound like music to your ears.