Don't think so. The oven recipe produces a nice time temperature profile,
and we have experimented with removing the gold. The results are near target
solder filets.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Dehoyos, Ramon
Sent: Friday, August 19, 2005 1:28 PM
To: [log in to unmask]
Subject: Re: [TN] max thickness electroplated gold
Hi Guy:
It could also be that the profile is burning off most
of the flux, the RSS profile maybe, the result is dull and grainy. A
ramp to spike profile or something in between as it is done by some,
forget the name of that profile, may be the solution.
Regards,
Ramon
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Guy Ramsey
Sent: Thursday, August 18, 2005 4:38 PM
To: [log in to unmask]
Subject: [TN] max thickness electroplated gold
Many of our customers are using the old MIL-STD-275 to specify gold
thickness for Hard Gold. They are ordering this because they are doing
both wafer and package testing at the die and device level. So, we are
seeing 50 to 100 uin of gold over nickel. It hasn't been much of an
issue because we build most of the boards by hand soldering methods.
We are starting to see components in the parts list for these assemblies
that cannot be installed with hand soldering methods.
When we solder with printed paste and reflow methods we see dull, grainy
joint that are clearly contaminated with gold.
When we hand solder this condition is not evident. (I believe the
condition may actually be worse because the dissolved gold is more
concentrated near the bottom of the fillet. But, that is another
discussion).
Does any one have a rule of thumb for the maximum thickness of
electroplated gold on land patterns intended to receive SMT components .
. . say, 0402 passives or MLFs?
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