Appeal No. 1998-0036 Page 6
Application No. 08/431,203
ordinary skill in the art were cognizant of the adhesion problem posed by the presence of absorbed
water in the organic material which is used in metallized polymer film laminates such as copper-
polyimide laminates. The references also show that those of ordinary skill in the art knew that vacuum
application results in desorption of the troublesome water and results in an increase in peel strength.
The various references use various levels of vacuum and heat to remove the moisture.
While the particular moisture levels recited in claim 1 of about 1% to about 2% by weight are
not expressly disclosed in the references, these levels are within the levels one of ordinary skill in the art
would have expected to result in adhesion improvements. The upper limit, about 2%, represents a
removal of up to half the moisture within a polyimide initially containing 4% by weight water. The lower
limit, about 1%, represents a removal of more than three quarters of the moisture in such a polyimide.
We note that the lower limit of “about 1%” is somewhat unclear. The specification provides little
guidance on the interpretation of “about”. In fact, the specification indicates that the true moisture level
resulting from the outgassing conditions may not be entirely known. The water level is only an
estimated level of “about 1% to about 2%” (specification, page 10, lines 17-25) based on the particular
vacuum and temperature conditions of the process used.
Under such circumstances, it would have been obvious for one of ordinary skill in the art to
perform routine experimentation in order to determine the workable ranges of vacuum and temperature
levels which would result in adhesion enhancing moisture reduction levels. We note that it is well settled
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