TECHNET Archives

August 2005

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:
Joe Russeau <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Joe Russeau <[log in to unmask]>
Date:
Tue, 9 Aug 2005 15:14:07 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (88 lines)
Hi Paul,

This is one of those "It Depends" questions.

Most of the studies I have read with respect to storage of tin-lead HASL
boards suggests a shelf life of up to twelve months.  I have not seen any
studies for boards with that surface finish being stored for that extended
period of time (2 years).  In my opinion, the ideal situation would be to
purchase the boards as you need them and eliminate the issues surrounding
extended storage. But since you already have the boards that is not an
option.

My 2 cents are to make sure that if you plan on storing them, that you
package for the long term (2 years) and not for the short term (6mos).  I
would suggest vacuum packaging them in a clean, moisture and debris
resistant container (e.g. Kapak heat-sealable bag). Depending on how many
boards you have to store and their dimensions, it may be advisable to store
them in a dessicated environment after vacuum sealing them.  Controlling the
humidity is going to be key to reducing the oxidation rate. Unless you use a
nitrogen blanket to store the boards, you will not eliminate oxidation, but
by controlling the humidity, you should be able to slow the process a bit.

It is hard to say what will happen after long term storage, but I would
suggest checking a few boards (provided you have extra) for solderability.
If the boards solder as you expect, then you may be safe to continue to
assembly. If you have problems, you may want to consider a mild saponified
wash to remove any oxidation or debris that has accumulated from storage and
repeat the solderability.  Best of luck!

Joe Russeau
Process Analyst

Precision Analytical Laboratory, Inc.
4106 Cartwright Dr. Ste. A
Kokomo, IN 46902

P: 765-455-1993
F: 765-455-1996
E: [log in to unmask]
----- Original Message -----
From: "Black, Paul" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, August 09, 2005 2:31 PM
Subject: [TN] PCB Storage


> Hi All,
>
> I have some bare PC boards that may be built up in the future, but not in
the near future. I would like to put them into storage until needed
(anywhere from 6 months to 2 years). The boards are .062" FR-4 HASL boards.
What would you recommend  for protection, assuming that the storage
conditions are typical of an office environment? Would I have to do anything
special to them when they are removed from storage? Any suggestions would be
greatly appreciated.
>
> Thank you,
> Paul Black
> Manufacturing Engineer
> Kronos
> E-mail: [log in to unmask]
>
> ---------------------------------------------------
> 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