In the case of vias being used at test point such as with a BGA's we have specified that the vias be covered or pluged on the topside and left open on the bottomside. If you plug the topside of the via solder will not fill the hole as you need positive pressure to move solder through a PTH or VIA in this case. Best regards Shawn C. Murphy Process Engineer 6640 185th Ave NE Redmond, WA 98052-5038 [log in to unmask] Tel: (425) 885-0107 Ext. 678 Fax: (425)867-5600 -----Original Message----- From: Jerry Mosur [mailto:[log in to unmask]] Sent: Tuesday, April 10, 2001 7:03 AM To: [log in to unmask] Subject: [TN] Masking Vias Hello, Have anyone specified via solder mask on top and not on bottom? I am trying to fill-in vias as much as I can. What pitfalls in term of assembly, reliability, etc.. I can expect? Thanks, Jerry ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------------