Hi Joe,
I have seen the method of baking parts at elevated temperatures used to
validate plating adhesion on plated RF connectors. It tests the bond of the
materials well and failure usually results in pealing or chipping plating
flakes under visual inspection.
Discoloration may be cosmetic or the result of failure. Testing is the best
way to determine which. Try to solder a lot sample and record the results.
I agree with treating the parts as a QA issue. Verify the materials stand up
to the specs that created them and disposition accordingly. If shelf life is
specified in the specs, you should have no trouble getting replacement parts
provided the parts are still within the appropriate time limit.
Bill Brooks
"The person who says it cannot be done should not interrupt the person doing
it."
--Chinese Proverb
-----Original Message-----
From: Barmuta, Mike [mailto:[log in to unmask]]
Sent: Thursday, July 24, 2003 3:35 PM
To: [log in to unmask]
Subject: Re: [TN] Gold plating shelf life and discoloration resolution
Hi Joe: First a couple of questions to help answer your question:
1. Has the gold thickness been verified to be > 1.5 microns on the actual
parts?
2. What type of gold plating is it?
3. What is the type and thickness of the Ni plating?
4. What is the problem the discoloration is causing, is it solderability or
is it a perception that they will be a problem?
As for comments in general:
1. If they were "properly" plated with electroplated 3-5 microns of Ni
followed by 1.5 microns of electroplated hard gold, the one year shelf life
should not be a problem. Thinner or different types of plating could be
problematic.
With a proper Ni undercoat as specified I don't think the porosity should be
an issue.
I also don't understand the vendors comments on baking, doesn't make sense.
If it's a solderability problem baking could make them worse and sure won't
help the discoloration.
2. As for the vendor, I feel they should have been willing to have some of
the parts returned for analysis to determine if the were defective or not
and if they met the drawing/spec. However you don't say whether it is a real
problem or perceived, just that the parts are discolored. I think the
vendor needs to know exactly what the issue is that he's being put on the
spot for.
Regards
Mike Barmuta
Fluke Corp.
Everett WA
425-446-6076
-----Original Message-----
From: Joe Fjelstad [mailto:[log in to unmask]]
Sent: Thursday, July 24, 2003 2:56 PM
To: [log in to unmask]
Subject: [TN] Gold plating shelf life and discoloration resolution
Hello friends from around the globe,
Component time limits seem to be a sore spot these days. This brings to mind
a related topic.
You see, I have a friend with a problem...
(I know what you might be thinking but the answer is: No, it really is not
me ;-)
At any rate, he received a quantity of ceramic chip carrier package shells
with gold plated leads over a year ago and upon removing them from storage
found many of them to be discolored near the copper/gold brazed welds
(apparently due to moisture from micro pores in the welds) The welds with
the micro pores were over plated with nickel and gold, with the final gold
plated to an average of greater than 1.5µm (60 millionths of an inch).
The vendor told him to bake them but it is hard to see how this will remove
and discoloration. They are also refusing to replace or repair the parts nor
will they say if the packages will be reliable in the field or take any
responsibility for them.
I realize that times are hard but the response seemed rather uncaring and
not very service oriented.
So the questions are:
1) What is the consensus expectation for storage life of gold plated parts
on a shelf in a benign environment with the plating series above?
2) What is the concessus on how folks here feel that the vendor should
respond?
A) Replace the parts? B) Repair them? or C) Tell the customer to eat them?
There are no right or wrong answers here. I am just looking for the valued
opinions of the many here who spend every day in the trenches on this
particular matter.
Thanks in advance to all who respond.
Kindest regards to all,
Joe ---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
