Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 11 May 2004 16:00:32 -0400 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Kerry - as part of a longterm wetting balance study I tested solderability
versus real time storage - laid out on strips to allow air flow. For ENIG I
ran out of coupons after 899 days. Solderability was still okay after this
time but wetting force was reduced 30+ % versus the original values. Your
parts are slightly older and your assembly flux will be stronger than my
test flux so you may not have any issues. Baking of the boards if FR4 should
not be necessary - their moisture uptake is very little, if Polyimide that's
another issue.
For HASL I ran the same test with HASL at a minimum thickness of 80
micro-inches - ran out of samples after 650+ days - not such a significant %
reduction in wetting force. Provided you have sufficient HASL deposit this
deposit should also be no problem
Regards
Gerard O'Brien
Photocircuits Corporation
-----Original Message-----
From: McMullen, Kerry [mailto:[log in to unmask]]
Sent: Tuesday, May 11, 2004 10:33 AM
To: [log in to unmask]
Subject: [TN] Bare PWB's - Storage Limits
Fellow Technetters,
I have two different boards (unpopulated) that have been in inventory since
May 2001.
One of the boards is ENIG, and the other is HASL.
They were stored in bags, but not sealed.
I want to populate them. I will inspect the plating on both boards, and
bake them prior to assembly.
Any other steps I should take?
Thanks,
Kerry
---------------------------------------------------
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
847-509-9700 ext.5315
-----------------------------------------------------
---------------------------------------------------
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 847-509-9700 ext.5315
-----------------------------------------------------
|
|
|