Easing the way to lead-free solder
Scientists at the National Physical Laboratory (NPL) are helping the electronics industry move to using lead-free solder alloys and meet regulatory changes, by researching how the potentially damaging 'tin pest' and 'tin whiskers' could affect them.
Tin pest, the allotropic phase transformation in tin and its alloys, can decompose tin into powder at low temperatures, which could dangerously affect the safety and functionality of electronic products used across many manufacturing sectors, such as the avionics industry. NPL has developed a method to measure the transformation rate to tin pest of lead-free alloys.
Pure tin component termination finishes are prone to the spontaneous growth of 'tin whiskers', which can cause catastrophic failures in electronic circuits. A new measurement system for evaluating the mitigation of tin whiskers by conformal coatings is available for use now, the test method can assess the ability of different conformal coatings to stop or slow down tin whisker growth. The method can also help developers to modify their coatings to inhibit whisker initiation, growth and penetration.