Another method is not to tent your vias. Currently we are using a 24mil pad with 12 mil hole with 19mil opening in the soldermask. We have not had any yield issues, even under .050 BGAs. Under the 1mm BGAs we use 20mil pad 10mil hole 16 mil soldermask. "Beerman, Dennis" <[log in to unmask]>@IPC.ORG> on 06/27/2002 09:19:39 AM Please respond to "(Designers Council Forum)" <[log in to unmask]>; Please respond to "Beerman, Dennis" <[log in to unmask]> Sent by: DesignerCouncil <[log in to unmask]> To: [log in to unmask] cc: Subject: Re: [DC] Tented Vias? LPI WILL slump into the hole, and your QA department may not be too happy with the results! We started using a via hole filler material, Peters SD2361 to fill the vias, with good success. I believe we started specifying tenting and filling to avoid any contamination that may reside in the barrel after processing and cleaning. -----Original Message----- From: Hybiske, Tom [mailto:[log in to unmask]] Sent: Thursday, June 27, 2002 8:17 AM To: [log in to unmask] Subject: [DC] Tented Vias? Correct me if I'm wrong members, but the term "Tented Via" was coined when dry film solder mask was popular. The film was allowed to cover, but not fill, the hole which both insulated it from adjacent copper features, and in our use, negated inspection of the via holes in general. It was good to use when specifying the option of plating to the point of closure, i.e.. 0.012 +.001-.012. Our inspectors would scrutinize untented vias that were specified in this manner, and an argument usually ensued. Covering them solved the problem. No partially filled holes. Nowadays with the use of LPI, I guess the term "tenting" is a misnomer as the material will slump and possible fill the hole rather than just covering it. At a previous employer, we first plugged the via holes with a liquid mask then covered them with LPI. I'm presently using a 24/10 via and just mask over it with LPI, so although while it's not tented, it accomplishes the same result. Tom Hybiske Bose Corporation The Mountain Framingham, MA 01701 > -----Original Message----- > From: Karthik, P.V.S. (IE03x) [mailto:[log in to unmask]] > Sent: Thursday, June 27, 2002 7:25 AM > To: [log in to unmask] > Subject: [DC] Tented Vias? > > > Hello All, > > I would like to know what is a "Tented Via" and its application . > > ---------------------------------------------------------------------------- ----- 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 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------