Mike, Exellent call! However not every BGA land will need a via tied to it. I did a quick scan of the micro BGA and did in fact find one via that would have been isolated from the plane. The rest are okay. Thanks for the input. Again good call. Greatly appreciated Dennis -----Original Message----- From: Mike Pulvermacher [SMTP:[log in to unmask]] Sent: Friday, March 31, 2000 2:54 PM To: TechNet E-Mail Forum.; Dennis Ward Subject: RE: [TN] Soldermask clearance Dennis, One factor to consider is that the power plane anti-pads required for the 13 mil via will likely overlap. This means that power and ground vias will not be able to tie to plane layers directly. Mike Pulvermacher Senior PCB/DFM Technologist Plexus Technology Group Direct: (920) 751-3295 Fax: (920) 751-5659 -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Dennis Ward Sent: Friday, March 31, 2000 1:32 PM To: [log in to unmask] Subject: [TN] Soldermask clearance Good afternoon everyone, Problem of the day. I'm trying to use a conventional via with a .8mm pitch microBGA. The spacing between the soldermask clearance around the land pad to the via pad is 2.7 mils. The via is cover with soldermask. What sort of problems should I expect with this situation? Will there be a problem? The via and land pad are not necessarily part of the same net. In case any one is interested the board parameters .093 thick board - 10 layers 13 mil via - 23 mils pad BGA - 9X9 .8mm pitch BGA ball size @.45mm (17.7 mils) BGA land pad @12 mils - 16 mil mask opening SMOBC LPI mask Any input appreciated! Dennis Ward Net to Net Technologies, Inc. 603 427-0600 [log in to unmask] http://www.nettonettech.com ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ############################################################## ############################################################## 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 Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################