Ioan,
Pardon me if this has already been commented on. Have been falling behind
in my Techie e-mails.
I've also seen something like this before, but it was related to
'over-activation' prior to electroless plating. In that case, however, the
slivers and feathers were under the solder mask. These look like they are
on top of the solder mask....
Are they on top of the mask? Or below?
If on top - is there a slitting, routing, etc. operation somewhere along the
board fab line that is creating the debris on your boards by
transference...?
If below the solder mask - check on plating issues.
Steve C
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of stephengregory5849
Sent: Wednesday, January 28, 2009 11:26 AM
To: [log in to unmask]
Subject: Re: [TN] Metal particles on the PCB
Hi Ioan!
Got your pictures finally and have them posted now, they're here:
http://stevezeva.homestead.com/files/Photo_002.jpg
http://stevezeva.homestead.com/files/Photo_004.jpg
I've seen something like this before, and it was caused by overetching which
caused plating slivers. Luckily, we found these before we populated the
boards. We rejected the boards back to the fab vendor and had them replaced
for new ones. We rejected them because of the possibilty that minimum
electrical clearances were being violated.
Steve
----- Original Message -----
From: "Ioan Tempea" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, January 27, 2009 1:48 PM
Subject: [TN] Metal particles on the PCB
Dear Technos,
I have these PCB shaving a lot of small, but visible with unaided eye, Au or
Cu particles on them, all over. I have sent Steve a couple of images, but in
the mean time I would like to state my questions.
As per IPC-A-610D, 10.4.2, this is a defect condition. The exceptions at
5.2.6.1 say this would be acceptable if the particles were entrapped in
flux, which is not the case.
Big part of the litter goes away if wiped with alcohol soaked cloth, but not
all. Brushing will not remove the leftovers, which seem to be well attached
to the soldermask, but a solid nail scratching will.
First of all: is this a defect?
Secondly, are there any better methods to clean than what I have tried?
Plasma and other funky methods are not an option and solvent cleaning is
probably not either, since the boards are already populated on one side with
no-clean flux.
Thank you,
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
Mtl : 514-990-5762
f : 450-967-7444
[log in to unmask]
www.digico.cc <http://www.digico.cc/>
P N'imprimer que si nécessaire - Print only if you must
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