Hi all,
the discussion reminds me of 'Salt Spray Test'. In the ingress you can see
an observandum that reads that 'this test does NOT correspond to a certain
environment, but is a test for COMPARISON of various components ' (not exact
phrase). Similarly, the mentioned solderability test can be used for
comparing boards from different manufacturers, or you can use the test for
best in show if you do a factor test. In such a case, the solderability test
may not necessarily correspond to your daily process window.
/Inge
----- Original Message -----
From: "Ioan Tempea" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, August 11, 2009 2:51 PM
Subject: [TN] PCB wetting issue saga, final question
Hello Technos,
I have been asking questions on Technet about some wetting issues we see on
a particular board and got many useful answers. In the end we've had the
boards tested for solderability by respectable labs and the bare boards
passed J-STD-003 testing with flying colors.
To back track a little bit, the original doubt came from the fact that in
reflow, the solder does wet very well on both the board and the component in
the component pin area, but would stop spreading pretty far from the land's
end. It just stops spreading, even though the wetting angles at the stop
points are very low, so denoting excellent wetting.
And here comes the question: why is testing per J-STD-003 done at 235 C and
with a rather aggressive flux, when the reflow soldering takes place at 205
C (HASL finish) using a milder flux (I am using WS, but it could very well
be no-clean...)?
Thanks,
Ioan Tempea, ing.
Ingénieur Principal Fabrication / Sr. Manufacturing Engineer
30 ans déjà! - Already 30 years!
950 rue Bergar, Laval, Québec, H7L 5A1
t : 450-967-7100 ext : 244
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