We're currently designing a flexi which will be populated with a micro BGA device, 0.35 dia balls on a 0.75 pitch. Someone told me in passing some time ago that joint reliability would be increased if the holes in the covercoat above the pads were made larger than the pads. This ensures the solderjoint is not undercut by the covercoat thus introducing a fatigue sensitive defect. The trouble is they didn't tell me how much to pull it back by. Does anyone know? Regards, 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 E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################