Judy, To paraphrase, you are going to take unsused pins and route traces to them, from ground net without providing access via hole to them. I don't see why this wouldn't work, but getting to them may be an issue. You may want to evaluate option like via in pad, or step drilling if the layer count and penetration through your planes are not allowing enough current capacity. You have probably already considered increased plating as well, but that is a thought. Since we don't know what he art looks like, we are being general in response... I don't think clean up should be a problem, especially if youre solder finish is electroplated variety and the mask is properly applied over tented vias. Rodney L. Miller, CID VP / Director of Manufacturing Tri-onics Inc. ph (618) 654-9831 fx (618) 654-6122 e [log in to unmask] <mailto:[log in to unmask]> -----Original Message----- From: Kile, Judy K (MED) [mailto:[log in to unmask]] Sent: Tuesday, September 30, 2003 4:11 PM Subject: BGA780 tied directly to gnd plane Hello, I am looking for potential issues with a proposed design "solution" on a 780pin BGA. Reason for this approach 1.) reduce ground bound to this BGA by tying unused pins to gnd 2.) minimize routing layers Proposed solution for the 1mm 780 BGA is to tie the BGA pads directly to a gnd plane (top side assembly & plane) very similar to the dog bone pattern. The thermal tie will be 1 "spoke" and covered with soldermask. There is ~25-30 unused pins that would be tied in this manner. ??? 1.) What are the potential assembly issues with solution? 2.) Are there any reliability issues long term? 3.) Are there other issues with this design proposal? Thanks for your advice, Judy Kile Global Electrical Technology Center Phone: 262-548-2241 Fax: 414-908-9584 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------