Die and method of making same

Abstract From the Canadian patent

A method for chemically milling an etchable workpiece by exposure thereof to an enchant in order to mill selected etchant-active areas and thereby form a plurality of raised die elements separated and bounded by a plurality of recessed cavities, which method is comprised of the steps of initially, partially etching the workpiece to form recessed die element precursors separated and bounded by recessed cavities, depositing a film of an etchant-resistant composition on the workpiece in at least selected ones of the recessed cavities, filling those selected cavities with an etchant-resistant filler and then subsequently processing the workpiece. In a highly preferred embodiment the method …