We have used Comco microblasting for many years without problems. There is no need for such a process today, so we sold the equiment. From what I remember, you need a special station with ionized air flow to avoid ESD risk. We used alumina powder, can't remember any problems. By the way, Comco has today gone through some improvements.

http://www.reed-electronics.com/semiconductor/index.asp?layout=article&articleid=CA267222&industryid=3026

Ingemar Hernefjord
Ericsson Microwave Systems

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Guenter Grossmann
Sent: den 7 juni 2005 09:11
To: [log in to unmask]
Subject: [TN] Antw: [TN] micro abrasive blasting for conformal coating
removal


micro shot blasting? Sounds interesting. Do you have any reference where
these things can be bought?

Best regards

Guenter

EMPA
Swiss Federal Laboratories  for Materials Testing and Research
Centre for Reliability
Guenter Grossmann,  Senior Engineer

8600 Duebendorf
Switzerland

Phone: xx41 1 823 4279
Fax :     xx41 1 823 4054
mail:     [log in to unmask]

>>> [log in to unmask] 03.06.2005 19:29:05 >>>
Has anyone used one of the micro shot blasting systems for removal of
conformal coating?

I have some concerns about static and the residue left behind. We use
a
moisture cure silicone coating, so abrasion works well to remove it,
but the
dry powder in the air stream must produce high static charges and if it
is
not possible to wash the assembly the shot residue will be left
behind.
There are multiple different shot materials offered including walnut
shell,
plastic pellet, and sodium bicarbonate. Since powders are difficult to
remove from the soft silicone coating, are there any of these materials
that
a trace residue left behind would not cause reliability issues?







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