My apologies, I read the pad size as 22 with an 18 mil mask opening, but you were referencing the via pad not the BGA pad.............. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Preuschl, Thomas Sent: Wednesday, May 10, 2006 11:09 PM To: [log in to unmask] Subject: Re: [TN] Unplugged via under BGA Hello John, what do you mean with 90 degree wetting angle? Tom -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Burke Sent: Wednesday, May 10, 2006 6:32 PM To: [log in to unmask] Subject: Re: [TN] Unplugged via under BGA 1 You should not be using solder mask defined pads particularly if you are going lead fre s gives a 90 degree wetting angle which acts as a stress riser. 2 If you are plugging the vias, you will not be able to do this at most fab shops on a silver finish. 3Yes I have reworked them obviously with the plugged via no problem on degradation. If the vias are unplugged, have used a process to apply a double layer of mask at the via hole only to protect it during re-work. This works great if you can't plug. 4 Do not have cost data available. John http://www.rohsusa.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Miswald, Ron Sent: Wednesday, May 10, 2006 7:41 AM To: [log in to unmask] Subject: [TN] Unplugged via under BGA All There is a board where this recently came up on. The vendor is one we haven't dealt with before. I looked in the tech net archives, and did not find an answer to this specific question. The vias under the BGA are 22 mil pad, 18 mil solder mask, and 12 mil hole. I usually ask for the vias to be filled or plugged... My question: 1) Has anyone else had experience with running this type of board? 2)If not, has anyone had them reworked? a)by who? b) what was cost per via, or board? Any shared experiences appreciated Ron --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------