Method and apparatus for cleaving a semiconductor wafer into individual die and providing for low stress die removal

Claim 1

A combination for cleaving a semiconductor wafer into individual die and providing for low stress die removal, comprising: A) a circular hoop having on its upper surface an adherent resilient air impermeable membrane, designed, when flat, to hold a semiconductor wafer applied thereto with substantial adhesion; B) a wafer cleaving apparatus, comprising (1) a rigid plate adapted to accept said hoop, including (i) means to seal said rigid plate to the bottom of said hoop to form a chamber under said membrane coextensive with said wafer, and (ii) an opening in said plate permitting the application of air pressure or a vacuum to said chamber; (2) a perforated first member through which air may pass contained within said chamber having an undulatory surface, disposed under said membrane and coextensive therewith; and (3) means for supplying air under pressure to said chamber via said opening for spherical inflation of said membrane, adherence of the wafer to said inflating membrane causing bending and tensile stresses on said wafer, internal strains resulting from the stresses cleaving the wafer at predetermined scribed lanes into individual die; and (4) means for applying a vacuum to said chamber via said opening to draw said membrane into conformity with said undulatory surface to provide decreased surface contact to reduce adhesion between the membrane and die to facilitate low stress removal.

Claim 5

A method of cleaving a semiconductor wafer into individual die and providing for low stress die removal, the wafer including an active surface, comprising the steps of: A) mounting a planar semiconductor wafer with the active surface exposed upon an adherent first resilient membrane supported along its perimeter by a hoop and scribing the exposed surface in scribe lanes along die boundaries, the first membrane being supported in a planar configuration during scribing; and B) applying uniform air pressure to said first hoop supported membrane for spherical inflation of said membrane thereby forming a convex surface of the first membrane with the wafer disposed on the convex surface, adherence of the wafer to said inflating first membrane causing ending and tensile stresses on said wafer, internal strains resulting from the stresses cleaving the wafer at predetermined scribed lanes into individual die; and C) applying uniform vacuum pressure to said hoop supported membrane while supported against an undulatory surface to cause said first membrane to conform to said undulatory surface to provide decreased surface contact between the first membrane and die to reduce adhesive forces to facilitate low stress die removal.

Claim 6

A method of cleaving a semiconductor wafer into individual die and providing for low stress die removal, the wafer including an active surface, comprising the steps of: A) mounting a planar semiconductor wafer with the active surface exposed upon an adherent first resilient membrane supported along its perimeter by a hoop and scribing the exposed surface in scribe lanes along die boundaries, the first membrane being supported in a planar configuration during scribing; and B) applying uniform air pressure to said first hoop supported membrane for spherical inflation of said membrane thereby forming a convex surface of the first membrane with the wafer disposed on the convex surface, adherence of the wafer to said inflating first membrane causing ending and tensile stresses on said wafer, internal strains resulting from the stresses cleaving the wafer at predetermined scribed lanes into individual die; and C) applying uniform vacuum pressure to said hoop supported membrane while supported against an undulatory surface to cause said first membrane to conform to said undulatory surface to provide decreased surface contact between the first membrane and die to reduce adhesive forces to facilitate low stress die removal.