The test you need to run depends upon your coupons.
For example, the dip test is good for smt, the rotary dip is for PIH product.
I recommend these two over the wetting balance testing.
Both of these tests call for a flux that is far more aggressive than most assy
processes use, and therefore the tests are quite out of date, its time we (ipc
members) took another look at them.
These tests will sniff out gross problems. If you think you have a more
marginal condition, I recommend a paste a reflow process; Here's what I
usually have done; Create the stencil the assy site will use for paste apply
(smt product). Stencil a no clean or water soluble fluxed paste down. Reflow
using the appropriate oven profile (IR Reflow), This test is more realistic,
though it does have some problems/limitations of its own. In its benefit it is
STATIC, (ie solder doesn't move -- more like smt assy process) and flux is less
aggressive.
Actually, in practice, you'll find the results are either good or bad, there
doesn't tend to be much "interpretation". Either the features have a nice
smooth bright uniform coating of solder, or they have something "strange".
Anything less than perfect is worthy of understanding and investigation
IF you fail these tests chances are your assembly site is doing a lot of
touchup , and you've been lucky not to get a complaint yet.
Hope this helps some
Jim Herard
IBM Microelectronics
Quality Engineering
[log in to unmask]
---------------------- Forwarded by Jim Herard/Endicott/IBM on 06-11-97 11:35 AM
---------------------------
Richard_Olsen @ contcirc.com
06-06-97 10:29 PM
Please respond to [log in to unmask] @ internet
To: technet @ ipc.org @ internet
cc: John_Maddux @ smtpr @ internet, Stuart_Lansburg @ smtpr @ internet
Subject: Solderability Tests of Boards
Hello,
I am interested in testing solderability of printed circuit boards.
There are 5 techniques mentioned in ANSI/J-STD-003 "Solderability
Tests for Printed Boards". They are : Edge dip, rotary dip , float,
wave, and wetting balance. The first three are done in a solder pot.
There is another method called "SERA Testing" that is not mentioned.
Do any of these prove reliable in predicting a boards performance
during assembly? Is it better to age the samples before testing? If so
then is steam aging the best method?
Interpretation of results seems to have a certain amount of
latitude. Is there a comprehensive authoritative work on the subject.
Some of the contacts for equipment manufactures mentioned in
section 6 of the document mentioned above are no longer valid. Are
there still sources for this equipment?
There is no source for wave solder testing equipment listed. Is
there a lab scale unit available?
I am interested in presenting a paper in September at the IPC
Summit on PWB Surface Finishes and Solderability in September titled
something like "Survey of Solderability Testing Techniques". I plan on
using information gathered on TECHNET in this paper. If you have
information and wish to assist please contact me.
Thanks
Rich
------------------------------------------------------------------
Richard Olsen Telephone (602)-232-9154
Continental Circuits Corp. Main (602)-268-3461
3502 East Roeser Road Fax (602)-268-0208
Phoenix Arizona Pager (602)-310-6245
85040-2905 Internet [log in to unmask]
USA I make circuit boards,what do you do?
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