TECHNET Archives

November 2004

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Chellis, Tammy" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Chellis, Tammy
Date:
Fri, 19 Nov 2004 14:48:39 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (123 lines)
The plugs are inserted from the top side of the board and the problem occurs
on both sides of the board. The problem that is driving this investigation
is due to voids in the conformal coating Conap -1170 that we apply using an
automated process. The vias with the copper appearance are the vias that
cause voids in the conformal coating. When I began the investigation I found
that they were conductive.

-----Original Message-----
From: Franklin D Asbell [mailto:[log in to unmask]]
Sent: Friday, November 19, 2004 2:19 PM
To: [log in to unmask]
Subject: Re: [TN]


Okay I'm curious now...what would you call a "standard" via?

Franklin

----- Original Message -----
From: "Jeffrey Bush" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, November 19, 2004 12:56 PM
Subject: Re: [TN]


Vias that are required to be plugged and tented should not have this
condition.  Weak LPI at the knee is due to the LPI running into the
barrel during coating, leaving a thin coating.  On a standard via this
is not normally an issue and many LPI materials have lower viscosity and
present more of an issue for via coverage.  Are the vias plugged and is
the condition on the opposite side of the plug?


Jeffrey Bush
Director, Quality Assurance and Technical Support

VERMONT CIRCUITS INCORPORATED
  76 Technology Drive - POB 1890
    Brattleboro, Vermont 05302
      Voice: 802.257.4571.21 Fax: 802.257.0011
           http://www.vtcircuits.com


-----Original Message-----
From: Chellis, Tammy [mailto:[log in to unmask]]
Sent: Friday, November 19, 2004 12:33 PM
To: [log in to unmask]
Subject: [TN]

We do incoming inspections on the PCB and we are having troubles with
identifying if variations in the LPI layer is acceptable. We are having
a
problem with coverage on the Vias. I
have a customer who specifies the vias are plugged and tented. I am
getting
boards with a copper color at some of the vias. I have tried to solder
and
it
will not take the solder but using a DMM the via is not electrically
isolated. I am not sure if this is a problem or not. Is a board in IPC
compliance
with out electrical isolation of a plugged and tented via?
The tenting is to be done with the LPI layer and appears to be very thin
on some vias. We are not trying to solder to them I just tiring to find
out
if it is a defect. The thing that does not make sense to me is the
conductivity to the via.

---------------------------------------------------
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
-----------------------------------------------------

ATOM RSS1 RSS2