Method of fabrication of long arrays using a short substrate

Claim 1

A method of forming a flexible array of circuit elements and electrical contacts interconnected by continuous wires, comprising the steps of (a) providing a body of semiconductor material having opposed major surfaces, (b) forming a plurality of said circuit elements on first major surface of said body, (c) providing conductive interconnections on said first major surface to interconnect said circuit elements, said conductive interconnections forming two or more substantially parallel, substantially linear regions, such regions connected at their ends by shorter regions substantially perpendicular to said parallel regions in such a manner as to form a continuous meandering path, (d) attaching a flexible polymer layer to said conductive interconnections and said first major surface, (e) providing an opening or openings in said polymer layer to allow contact to said conductive interconnections, (f) removing portions of said body of semiconductor material by etching, leaving separated islands of semiconductor material supported by said polymer layer, (g) attaching an additional polymer layer over the second major surface of said islands and polymer, forming a resulting layer of polymer which encases said islands (h) cutting said resulting polymer layer between and substantially parallel to said parallel regions, but not through said perpendicular regions, (i) folding the said resulting polymer layer through an angle of approximately 180° about an axis perpendicular to said parallel regions, where such fold point is at or near the juncture of said perpendicular region with one of said parallel regions, and then (j) folding the said resulting polymer layer through an angle of approximately 180° about an axis parallel to said parallel regions, where such fold point is at or near the juncture of said perpendicular region with the other adjacent parallel region, and (k) fastening said resulting shape to make it retain its folded shape.

Claim 2

A method of forming a flexible array of circuit elements and electrical contacts interconnected by continuous wires, comprising the steps of (a) providing a body of semiconductor material having opposed major surfaces, (b) forming a plurality of said circuit elements on first major surface of said body, (c) providing conductive interconnections on said first major surface to interconnect said circuit elements, said conductive interconnections forming two or more substantially parallel, substantially linear regions, such regions connected at their ends by shorter regions substantially perpendicular to said parallel regions in such a manner as to form a continuous meandering path, (d) attaching a flexible polymer layer to said conductive interconnections and said first major surface, (e) providing an opening or openings in said polymer layer to allow contact to said conductive interconnections, (f) removing portions of said body of semiconductor material by etching, leaving separated islands of semiconductor material supported by said polymer layer, (g) attaching an additional polymer layer over the second major surface of said islands and polymer, forming a resulting layer of polymer which encases said islands (h) cutting said resulting polymer layer between and substantially parallel to said parallel regions, but not through said perpendicular regions, (i) folding the said resulting polymer layer through an angle of approximately 180° about an axis perpendicular to said parallel regions, where such fold point is at or near the juncture of said perpendicular region with one of said parallel regions, and then (j) folding the said resulting polymer layer through an angle of approximately 180° about an axis parallel to said parallel regions, where such fold point is at or near the juncture of said perpendicular region with the other adjacent parallel region, and (k) fastening said resulting shape to make it retain its folded shape.