TECHNET Archives

March 2007

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:
Ian Hanna <[log in to unmask]>
Reply To:
Date:
Tue, 6 Mar 2007 16:26:11 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (157 lines)
That's why they build church roofs out of it I suppose...

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kevin Glidden
Sent: Tuesday, March 06, 2007 4:20 PM
To: [log in to unmask]
Subject: Re: [TN] immersion silver and exposed copper in small vias

Is this really true?  I have only been at this around 7 yrs, but
everything
I was ever taught says exposed Cu is not allowed for risk of corrosion.
 

-----Original Message-----
From: Wayne Thayer [mailto:[log in to unmask]] 
Sent: Tuesday, March 06, 2007 3:52 PM
To: [log in to unmask]
Subject: Re: [TN] immersion silver and exposed copper in small vias

And what's wrong with exposed copper?  You certainly aren't going to try
and
solder down there, are you?  Copper does not corrode quickly, and if its
going to be in a corrosive environment, you're going to have to
conformal
coat anyway!

The silver is put on boards only to extend the solderability lifetime of
the
bare copper, not as a protectant to prevent opens due to corrosion.

This is not a reliability issue at all.

Wayne Thayer

>>> [log in to unmask] 3/6/2007 12:10:08 pm >>>
Hi Fran
The amount of mask intruding into the hole will depend on the
application
method. Our curtain coat operation can cause the mask (circa
1-2 microns) to penetrate about 1/3rd into the hole from both sides but
it
has not affected the silver taking on the remaining surface. Is the mask
too
thick at the hole entrance to prevent the plating solution getting good
access?
You may also need to confirm by micro section what your customer thinks
he
is seeing. Is the mask covering all the hole surface? Hope this helps.

Regards

Alistair

Alistair F Murray   MICT
Technical Manager
Artetch Circuits Limited
England UK
Direct Dial: 01903-712931

www.artetch.co.uk 


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Fran Juliot
Sent: 06 March 2007 15:58
To: [log in to unmask]
Subject: [TN] immersion silver and exposed copper in small vias

Our customer is questioning what they feel is exposed copper in 8 mil
vias
holes on silver boards.  We feel there is mask residue in the holes
which
does not allow silver to take.  These are holes that are allowed to be
plugged.  Has anyone else ran into this issue with thier customers and
do
you have the same look or are your small vias covered with silver all
the
way through the via?  

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 15.0
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 15.0
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