Abstract: A substrate having embossed thereon a plurality of shaped recesses of a predetermined precise geometric profile, each recess having a flat bottom surface having a major dimension of about 500 &mgr;m or less, the substrate being capable of undergoing a thermal cycle of about one hour at about 150° C. while maintaining about ±10 &mgr;m or less dimensional stability of the embossed shaped indentations, and wherein the substrate comprises an amorphous thermoplastic material. During the thermal cycle the substrate has an elastic modulus greater than about 1010 dynes/cm2 and a viscoelastic index of less than about 0.1.

Abstract: A substrate having embossed thereon a plurality of shaped recesses of a predetermined precise geometric profile, each recess having a flat bottom surface having a major dimension of about 500 &mgr;m or less, the substrate being capable of undergoing a thermal cycle of about one hour at about 150 ° C. while maintaining about ±10 &mgr;m or less dimensional stability of the embossed shaped indentations, and wherein the substrate comprises an amorphous thermoplastic material. During the thermal cycle the substrate has an elastic modulus greater than about 1010 dynes/cm2 and a viscoelastic index of less than about 0.1.