Hi Luis,

        I see you are still pursuing the PWB business, it's been a few years
since Dallas, but this old boy is still working in the field. To answer your
question, CIC is still being made and utilized in constrained core boards. As
far as the aramid being utilized, it is also, But don't be deceived it has it's
own set of problems. I'm sure they are not insurmountable, but if you go this
route, be prepared for some development effort. As you may recall there are
some problems in getting a good bond to CIC as well. Gould can supply a good
surface for bonding, however.

Regards,

Les Connally

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>  From: Luis Rivera <[log in to unmask]>, on 8/12/97 6:00 AM:
>  In the last few weeks, we have had a few customers ask about boards
>  with copper-invar-copper cores used in their construction.
>
>  A few years ago, while working at another PCB fab facility, I used to
>  hear that the CIC cores themselves where difficult to obtain, and
>  that once a source was secured, that it was difficult to work with
>  the CIC material. Comments were made as to the lamination, drilling
>  and plating processes not being trivial when CIC substrates were
>  introduced into the picture.
>
>  Recently, I have heard that aramid dielectrics are an easier
>  alternative to fabricating boards that match the X-Y CTE of ceramics.
>
>  Is it still difficult to obtain CIC cores? Can anyone offer comments
>  on what it takes to get into the CIC business? Are aramid materials
>  indeed easier to pursue?
>
>  Thanks,
>
>  Luis Rivera
>  CompuRoute, Inc.
>  [log in to unmask]
>
>