1.) I am going to assume that you mean 0.8mm, not 8mm for the BGA pitch, 2.) and that you are using 0.3mm diameter lands. 3.) Based on these criteria and on input from one of the fabricators I work with I use 0.1mm drill / 0.45mm pad (internal and external) and .1mm trace and space design rules. 4.) Remember to fan-out all unused balls to via, and teardrop all connections and you should get a reasonable yield out of the design. Jeffrey A McGlaughlin, CID Engineering Designer Battelle Memorial Institute Columbus Ohio http://www.battelle.org [log in to unmask] -----Original Message----- From: Fred Dark [mailto:[log in to unmask]] Sent: Wednesday, June 25, 2003 1:57 PM To: [log in to unmask] Subject: [DC] 8mm pitch BGA Hello All, I Would like to know if anyone has used a BGA with a 8mm pitch. What I'm looking for is some design recommendation... What via size to use and trace width and clearances... Thank's, Fred Dark Jr. ---------------------------------------------------------------------------- ----- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------