As a medium volume PWB manufacturer, with a large portion of our business
in the Telecommunications field, we have found quite slow acceptance of the
OPC finishes in this market. Even though Bellcore have no fundamental
objections to the finish, the issue of "apparent exposed copper" after
assembly continues to be the major hurdle to overcome, at least in the minds
of our customers. This is copper on the top side of the board which is not
tinned during wave solder or fusing.

        The customers who have converted have all had to modify their
assembly methods to some degree. Solder paste and flux, and temperature
curves all need to be reviewed.

        The benefit which our customers have realised is in a price
reduction of 2 to 4% from an equivelant HASL product. On a typical 4 layer,
18 by 24 panel, this would be in the order of $1.50 to $3.00 depending on
complexity. This benefit is a straight pass through savings in our costs. We
run a conveyorised, dedicated line, for OPC application minimising the
handling issues associated with batch type "dip" methods. Other areas where
the savings come from include, lower line maintenace costs, compared to our
horizontal HASL and yield improvements from elimination of solder shorts and
reduced damage to soldermask.

        As discussed in some of the other replies to your request the
savings and benefits will vary depending on the individual board shop and
end user requirements. The industry still seems to be a long way from
universal application of this finish.

Regards
	Keith Lumley, Rexcan Circuis, Inc