Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 21 Nov 2000 18:52:40 -0600 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Hi Albert! I can shed some light on your question: Steam conditioning is
one method of determining the robustness of a tin or tin/lead printed
wiring board finish. The JSTD-003 committee has two studies which show that
steam conditioning can be used to differentiate between poor plating and
good plating for plated thru holes pwbs. Note I didn't not say steam
"aging" - the next revision of JSTD-003 will contain this verbiage change.
There is no correlation that steam conditioning is equal to any amount of
storage time and in fact there are two studies which show that the tin
oxide produced in steam conditioning is not the same tin oxide produced
during typical storage conditions. There are several printed wiring board
fabricators which can produce a tin or tin/lead finish which can survive
hours of steam conditioning but you need to ask yourself two questions: a)
do I want to pay extra for that type of finish (nothing is free in life)?;
b) do I really need a tin or tin/lead finish which will survive steam
conditioning for the amount of storage time/conditions I expect to see in
my soldering processes?. Most people do not need tin or tin/lead finishes
which can survive steam conditioning. Also, the JSTD-003 committee has
shown that steam conditioning is not applicable to other pwb finishes such
as OSPs or silver. The Alternative Final Finishes committee is working on a
round robin study which may produce a set of conditioning parameters which
can be used for all pwb finishes - that data should be published by mid
2001. Hope this helps.
Dave Hillman
JSTD-003 Committee Chair
[log in to unmask]
¿àÁJ·½( sylai ) Q80_5381 <[log in to unmask]>@IPC.ORG> on 11/21/2000
06:39:08 AM
Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
to ¿àÁJ·½( sylai ) Q80_5381 <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
To: [log in to unmask]
cc:
Subject: [TN] Fw:Steam Aging
Dear Technetters,
???? For IPC-J-STD-003, the solderability test after steam aging is only
for tin and tin/lead coatings board. Why is this? For other coatings
board, say gold or silver, do the test have the mean? If have, how can?I
do the?test??Where can?I find?the description about these? Please tell me.
Thanks!
|
|
|