Hi, As we all know the standard shape for 50 mil pitch BGA used the via hole (usually with dia of 12 mil finished with 25 mil pad) connected with trace to the ball's pad (25-27 mil). When speaking of standard aspect ratio there is no problem with that design but when going up to 160 mil board thickness this design is almost impossible for most of the manufacturer( A.R=13.3). My question is if there is any problem with the following design: - Ball's Pad dia.- 35 mil - The via hole dia. located on the ball's pad: 16-20mil That design will contribute to the manufacturability of the board regarding the aspect ratio, the reliability of production will increase and we'll free some space at the BGA's area that will make the option of 5 mil trace route at that area more easy. I would appreciate any comment and if any one experience that design type. Best regards, Tamir Ben-Shoshan Charlotte's Web Networks --------------------------------------------------------------------------------- Technet 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet 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 ---------------------------------------------------------------------------------