Did you see the DigiTimes story last week?
“Although the major cause of the recent Sony battery recall has not been revealed, passive component makers suspect that cracking of the multi-layer ceramic capacitors (MLCCs) or the inappropriate use of negative temperature coefficient (NTC) resistors caused the batteries to overheat.
“Sources at US-based passive component makers commented that overheating may have originated in the electrical insulation of the batteries and that MLCC and other passive components should not be the major cause of the incident.
“Some Taiwan-based makers, on the other hand, suspect that the adopted MLCCs had been cracked by printed circuit board (PCB) assembly, and that this may have caused an unstable flow of current, leading eventually to overheating.”
So some are suggesting that lead-free is behind the Sony battery failures. As Kathy Nargi-Toth, my colleague at Printed Circuit Design and Manufacture, says, “Make that link and we might have an interesting situation.”
We are one of the most successful PCB manufacturers in the UK and we believe it is no longer acceptable to ignore the complexity of the printed circuit board when considering the implications of the lead free assembly process; the interaction between PCB Design, PCB Manufacture and PCB Assembly does have an effect on the product during its manufacturing life. Lead Free assembly temperatures have been shown to affect the pcb during the wave process and can cause de-lamination along with other assembly issues: tomb-stoning, copper dissolution, out gassing, pad cratering, poor wet out, etc.,.
As an experienced PCB manufacturer, we are reacting to feedback from our customers by providing guidelines for Lead Free Assembly from the laminate manufacturers on our website.
Please visit http://www.lyncolec.co.uk and you will find this from the dropdown capabilities menu under technical. See also under quality menu for the â€œBest Practice â€œguidelines for packing lead free boards.