"Nothing solders like solder!" An old, but true saying. Try pretinning. If it won't pretin, it won't solder well in all likelyhood. My experience. Ron Dieselberg -----Original Message----- From: Eric Christison [mailto:[log in to unmask]] Sent: Thursday, October 21, 1999 08:36 To: [log in to unmask] Subject: [TN] Micro BGA on Flex I'd be interested in hearing a few opinions. Weve built a small batch of flex PCB's populated with a micro BGA. We used Ni/AU on the pads and got a terrible yield due to poor solder wetting. We're having another go and this time we're thinking of trying HASL or immersion tin instead. Which would be better? Thanks, Eric Christison Mechanical Engineer VLSI Vision Ltd Aviation House 31 Pinkhill Edinburgh EH12 7BF Tel: +44 (0) 131 539 8165 Fax: +44 (0) 131 539 7141 A company of the STMicroelectronics Group ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################