I'd find a new assembly house. We use soldermask encroached vias and fan out typical 1mm bga's that have 21 mil pads with 20 mil vias and hold around 7.34 to 7.35 mils spacing. The key is to encroach the vias. My 20 mil via has an 8 mil plated hole. The soldermask opening is only 14 mils in diameter. Good luck. Jim S. Wages / SR. PCB Layout Designer: Cary, NC - (919) 466-1596 -----Original Message----- From: icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Mark Salberg Sent: Thursday, February 16, 2006 4:25 AM To: Cadence User Group Subject: [PCB_FORUM] BGA Fanout / Filled vias Hello all, What BGA Ball pad to via clearance is needed for BGA fanout? Our Assembly house is telling us that we need 10 mil copper to copper (15mil preferred). On 1mm BGA's using an 18mil via with 8mil drill gets us 9.8mil via to pad. On our .75mm BGA this via gets us 4mil via to pad. Which also breaks the soldermask dam. Is epoxy filled and tented vias our best or only option at this point? Thanks for any input. Mark ________________________________________________________________________ _____ Scanned by IBM Email Security Management Services powered by MessageLabs. For more information please visit http://www.ers.ibm.com ________________________________________________________________________ _____ ----------------------------------------------------------- To subscribe/unsubscribe: Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx with a subject of subscribe or unsubscribe To view the archives of this list please login at //www.freelists.org. Our list name is icu-pcb-forum or go to //www.freelists.org/archives/icu-pcb-forum/ Problems or Questions: Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx Want to post a job listing ? DON'T DO IT HERE! Better yet, join our jobs listing forum. SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx POST: icu-jobs-forum@xxxxxxxxxx ----------------------------------------------------------- ----------------------------------------------------------- To subscribe/unsubscribe: Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx with a subject of subscribe or unsubscribe To view the archives of this list please login at //www.freelists.org. Our list name is icu-pcb-forum or go to //www.freelists.org/archives/icu-pcb-forum/ Problems or Questions: Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx Want to post a job listing ? DON'T DO IT HERE! Better yet, join our jobs listing forum. SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx POST: icu-jobs-forum@xxxxxxxxxx -----------------------------------------------------------