The Print did not specify SMOBC. But it also didn't specify SOS (Soldermask
over solder) either! The implication is that the order of the notes IMPLIES
that we want soldermask after the solder coating process.  Don't all PCB
vendors know that the solder under the soldermask will reflow, wrinkle and
damage the soldermask in assembly?  If we have soldermask on a thru hole
technology board.... we are going to wave solder the board. Why would a
vendor interpret the drawing in such a way as to compromise the performance
of the board? I can't believe this is still happening in 2002. I thought we
learned our lesson back in 1980.....the first time I ever saw anyone DO
that...

 Doesn't IPC have a spec that tells us not to do it that way?

Bill Brooks

-----Original Message-----
From: Steve Gregory [mailto:[log in to unmask]]
Sent: Tuesday, October 22, 2002 11:44 AM
To: [log in to unmask]
Subject: Re: [TN] Solder UNDER Soldermask Accept/Reject Criteria?


Hi Bill!

Was that called out on the fab drawing? I've ran across a few boards here
that still call that out on the drawing, and TRY and get that changed before
the boards are fabbed...most of the time I've been lucky, but there's been a
few that slipped by me.

Bottomline, if it's called out on the drawing, you don't have much
recourse...

-Steve Gregory-




Anyone aware of a spec that sets the accept/reject criteria for boards that
come in with solder UNDER the soldermask? Is this actually done as a
legitimate practice? WHY would a vendor make the boards this way? Shouldn't
we be making all boards to be SMOBC when there is a soldermask?

Bill Brooks




--------------------------------------------------- Technet Mail List
provided as a free 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/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 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------