Hi Terri, A possible alternative to Charles's suggestion, (and his would probably be the preffered route), would be to consider something like Pd (3-12uin )over EN(50-100uin) with Au flash, this is "potentially" an expensive option, but has been succesfully used as a wire bondable and solderable metallurgy. You will need to re-evaluate your wire bond process for Pd, and also you would expect a shorter capillary life due to the high hardness of Pd. One word of warning though, the Pd is real thin, and needs to be handled real careful to avoid scratches etc. If going to a Pd finish, its a pretty big undertaking, but it is an option, and has been used in volume manufacture Good luck Roger Roger Massey Materials Technologist Motorola AIEG UK -----Original Message----- From: Houston, Terri [mailto:[log in to unmask]] Sent: 26 October 1999 06:19 To: [log in to unmask] Subject: [TN] Board finish for BGAs and wirebonds Hi, We're designing boards that will use both solderable (BGA and QFP) components and wirebonded die (that need gold bond pads). It also looks like the QFPs will be on the backside of the board in the "shadow" of the BGA topside component. I would appreciate any advice on: (1) recommended surface finish on the board (2) component placement guidelines Thanks, Terri ############################################################## 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 ##############################################################