Are the vias being used as test points? if they are then you would not want them to be tented. Have you asked the customer why they are so resistant to changing there design? Ted -----Original Message----- From: Rick Thompson [mailto:[log in to unmask]] Sent: Thursday, April 19, 2001 9:46 AM To: [log in to unmask] Subject: [TN] Vias under BGA's - Tented or Not?? Hi, We're running several designs from a new customer with multiple BGA's. The boards are laid out such that the vias under the BGA's are not soldermask tented on either side. Our experience with this type of layout is for a greater tendency to bridge as well as requiring the bottom side to be masked prior to any wave solder operation. The customer is resistant to changing this layout but I'd like to get some other opinions. My questions are: What are others doing in terms of PCB layout of BGA's? Is the above layout common? What if any trends are there in the industry for these types of layout? Thanks in advance for any insights. Rick Thompson Ventura Electronics Assembly 2655 Park Center Dr. Simi Valley, CA 93065 +1 (805) 584-9858 x-304 voice +1 (805) 584-1529 fax [log in to unmask] ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------