As an Enthone-OMI representative, I am very pleased to continually read
positive responses to "ENTEK" questions.

The industry is rapidly accepting organic solderability preservative (OSP)
coatings as an alternative to hot air solder leveling (HASL).  This has been
primarily due to the growing number of assemblers reporting increased first
pass yields when processing cards coated with OSP in place of HASL.
 Fabricators, with installed OSP processes have reported many advantages as
well.

As I have read the many articles in this forum, a concern has come to mind,
and since the children are all nestled in their beds (meaning I get some time
on the machine) I thought I would bring it to the group's attention.

Occasionally, a product hits the marketplace and becomes the namesake for the
process it represents.  Such is the case for "ENTEK".

The word "ENTEK" does not in fact describe a product, or coating process, due
to the fact that there are two products with the name "ENTEK" included, ENTEK
CU-56 and ENTEK PLUS CU-106A.

ENTEK CU-56 has been used as an OSP (HASL alternative) for over twenty years.
 The major definition is that it forms a mono-molecular coating on copper
 which can break down after one thermal excursion.

ENTEK PLUS CU-106A is a more robust coating as it should build a thickness of
0.2 to 0.5 microns on copper and will yield good solderability through 5
thermal excursions in assembly.

Likewise, the term Organic Solderability Preservative (OSP) is a generic term
for any organic coating which preserves copper for subsequent soldering
processes.  ENTEK CU-56 and ENTEK PLUS CU-106A fit into the OSP category,
however, other OSPs do not perform the same as ENTEK CU-56 or ENTEK PLUS
CU-106A.

The purpose of my little rant here is that we should be careful when
describing any circuit coating so that the troubleshooters hit their mark.

With regard to the recent questions about teflon cards, the people from
Automata and Merix have covered them well.

As to the nickel / gold inquiries, there are several studies such as
K.Banerji that would answer many of the questions raised.  We have compiled
many of these reports into a booklet to facilitate your review.

Please contact me if you are interested in any futher information regarding
the above.

Tom Eshelman
Enthone-OMI Inc.