There are a variety of methods for
application of electrolytic nickel/gold
to printed circuit boards, most use a
buss connection to the features which
is removed at the routing or secondary
drill operations. The buss can be
internal or external however serves the
same function. Some designs do not
allow a buss type connection, it
becomes necessary to use the base foil
as the buss after pattern plate prior
to etch. A selective gold application
requires an additional coating of dry
film photo resist to cover all but the
features to be nickel/gold plated. The
nickel/gold process is very aggressive
on photo resist, causing film lifting
and under plate of nickel/gold under
the film.

	Does anyone in the manufacturing
industry know of a photo resist capable
to survive this process without 
lifting ? (double coat,image and
develop)

	How are other manufacturers coping
with nickel/gold application when buss
connections are not an option ? 

Electroless nickel/gold is an even more
aggressive process than the
electrolytic process, is there a
process to apply hard gold selectively
to boards with the electroless process?
What is used to mask the other portions
of the board ?

Tony King
Elexsys International Inc.
Nashua N.H.
[log in to unmask]
603-886-0066

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