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Curved Silicon Electronics

Published online by Cambridge University Press:  15 February 2011

Linlin Wang
Affiliation:
Material Science & Engineering
Dieter G. Ast
Affiliation:
Material Science & Engineering
Peeyush Bhargava
Affiliation:
Theoretical and Applied MechanicsCornell UniversityIthaca, NY, 14853-1501
Alan T. Zehnder
Affiliation:
Theoretical and Applied MechanicsCornell UniversityIthaca, NY, 14853-1501
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Abstract

An electronic imaging system using a curved image sensor can use a faster lens, and cover a greater field of view, than an imaging system using a planar sensor. The simpler lens systems also weight less, a decisive advantage in portable applications.

This paper describes a method to fabricate a curved silicon substrate from a flat wafer containing appropriate circuits. To curve the substrate, the processed wafer is diced, by dry-etching from the backside, into 1x1cm tiles. The tiles are separated by 0.5mm gaps, which are bridged, in turn, by a dense array of 45x100μm gold leads formed by electroplating using lithographically defined leads as seeds. Two methods were used to curve the wafer. In the first one, the wafer was bonded with epoxy to a PMMA disk, and then curved by heating the sandwich, under a load of ∼ 230gr, for 1.5 hrs at 130°C in a concave metal mold with a radius of curvature of 7.8cm. In the second method, the wafer was put into a curved metal mold, radius 14cm, loaded with 230gr, and heated to 290°C for 2 hrs. The normal and shear strains accommodated by the flexible interconnects were measured by analyzing their deformation. The experimentally measured strains are compared with a model that calculates the deformation required to deform a flat sheet into a spherical surface.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

[1] McLoughlin, J.R. and Tobolsky, A.V., J. Colloid. Sci, Vol 7, (1952) 555 Google Scholar
[2] Monroe, Tiara, REU report, CCMR, Cornell University (2001)Google Scholar
[3] Alekseyev, Leo, REU report, CNF, Cornell University (2000)Google Scholar