. . "As an example, SU-8-25 (Microchem Corp.) may be spun on the substrate at about 1,000 to about 3,000 rpm, for example about 2,000 rpm, to provide a film having a thickness of about 10 to about 100 ??m such as from about 20 to about 50 ??m or from about 20 to about 40 ??m." . .