At 20:02 23/03/98 +0000, you wrote:
>Hello all;
>I would be interested in hearing any comments about etching down 1oz.
>copper foil to 1/4 oz or 3/8 oz.  It is our understanding that this requires a
>specific equipment set to control the uniformity of the thickness across
>the panel surface; it is also our understanding that chemical control is
>very important (although I am not sure what types of chemistry may used
>for this process, i.e. cupric, sulfuric/peroxide, etc.).
>
>Any suggestions for equipment and chemistries would be appreciated.
>
>Regards,
>Fred Johnson
>JMSPI

Fred !
To do such job You really do need very good and sofisticated etching
equipment . All kind of spray equipment I know is not able to assure good
distribution after etching . On spray machines there is allways overetching
of edges . I might be easier in immersion with microetch solutions (
persulfates , peroxides ) , but take into account how long I will take !!
I guess You need it for fine lines . From cost and yield point of view it is
better to use 1/4 oz copper foil with protection sheet .
Edward
Edward Szpruch
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]

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