Loctite 3508 is a Cornerbond underfill system designed for CSPs and BGAs in Pb-free environments. Benefits reportedly include higher throughput, reduced manufacturing costs and improved pot life. Is a one-component epoxy cornerfill engineered for process optimization with curing taking place during normal Pb-free solder reflow. Said to permit component self-alignment. Is preapplied to the board at the corners of the CSP pad site using a standard dispensing system. Has six-month shelf life, a pot life greater than 75 hours, and can be stored under standard refrigeration. Other advantages reportedly include improved adhesive strength over previous versions and a reworkable feature that enables defective components to be removed.
Henkel Corporation,
www.electronics.henkel.com