Lou,
This Apache Indian, who split his time between living in a Tee Pee on one
Reservation and a Wigwam on another, was suffering from anxiety. He went to
a Doctor who described his condition as " too tense".
If your market is such that your PWB( board) is disposable, it doesn't
matter: one tent; two tents; or no tents. After all a nod is as good as a
wink to a blind Horse.
If you are looking for long term reliability, a LPI Solder Mask on both
sides of the via is a must. In some cases( hole size, end use environment ),
the via must be plugged or filled before the LPI Solder Mask is applied.
Some people use plated-over filled vias, where the Solder Mask may or may
not be applied.
The Customer and Supplier must work together to choose a proper ( conductive
or non-conductive ) filling or plugging material and processing technique to
meet the defined needed criteria for acceptance.
There are Companies in China that can do this.
Dewey
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Takach, Lou J
Sent: Tuesday, March 22, 2005 4:53 AM
To: [log in to unmask]
Subject: [TN] VIA Tenting Question
Good Morning Technetters....
I have a VIA tenting / plugging question. For quite some time, we have been
requiring a 100% plug in our VIA's. LPI mask was then applied over the plug
giving us tented VIA's on both sides of the board. Within the last year and
a half, we started receiving boards from offshore suppliers (China). We
noticed that the VIAS were not plugged. The solder mask was applied and
whatever material ran into the holes was what they delivered. After
reviewing, we found that most, if not all, offshore suppliers could not plug
the VIAS's. By the way, our domestic suppliers had no trouble with this
process. Anyway, with the considerable cost savings achieved by using China
as our supplier, we modified our spec, removing the plug requirement. Now
when we receive our boards from our domestic supplier, all of our VIA's are
exposed, i.e. not tented with soldermask. We were told that they could give
us a partial plug and then tent on one side, but not both. I need some
advice. We want the VIA's to be tented on both sides. How would you
accomplish this?
Thanks in advance...
Lou Takach
Union Switch & Signal
Pittsburgh, PA
412-688-2574
---------------------------------------------------
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
-----------------------------------------------------
|
