Machine for grinding an edge contour on a semiconductor wafer

Claim 2

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine comprising: a chuck for holding the wafer; means for rotating said chuck; a grinding head having a plurality of resilient grinding elements extending therefrom, each of said resilient grinding elements having a grinding surface facing the wafer held by said chuck, means for moving said grinding head laterally in a circular path that is substantially coaxial wIth the axis of rotation of said chuck, said chuck and said head being longitudinally spaced to cause the grinding surfaces of said grinding elements to be pressed resiliently against the edge of said wafer at all relative positions of said head and said chuck, and the angle between said grinding surface of each of said grinding elements and the axis of said chuck being less than 90* at each point of contact between said grinding surface and the edge of said wafer so as to form a rounded contour on said edge.

Claim 3

The grinding machine of claim 1 comprising, in addition, means to adjust the position of said grinding head laterally with respect to said wafer.

Claim 4

The grinding machine of claim 1 in which said edge of said semiconductor wafer comprises a circular portion and a straight portion, and said chuck is a vacuum chuck to hold one of said wafers at a time.

Claim 5

The grinding machine of claim 1 comprising, in addition, means to move said grinding head toward and away from said chuck to control the pressure of said grinding surface against said wafer.

Claim 6

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine comprising: a chuck for holding the wafer; means for rotating the chuck; and a grinding device including a head spaced axially from said chuck, and a plurality of grinding elements spaced apart about said head, each of said grinding elements being constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of the chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck to provide a grinding surface facing toward the wafer held by said chuck, the angle included between said shank portion and end portion of said flexibly resilient rod being greater than 90*, and the axial spacing of said head and said chuck being selected to cause said grinding surface of each of said grinding elements to be pressed resiliently against the edge of said wafer held by the chuck in all rotary positions of the chuck.

Claim 7

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine comprising: a chuck for holding the wafer; means for rotating the chuck; and a grinding device including a head spaced axially from said chuck, and a plurality of grinding elements spaced apart about said head, each of said grinding elements being constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of the chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck to provide a grinding surface facing toward the wafer held by said chuck, the angle included between said shank portion and end portion of said flexibly resilient rod being greater than 90*, and the axial spacing of said head and said chuck being selected to cause said grinding surface of each of said grinding elements to be pressed resiliently against the edge of said wafer held by the chuck in all rotary positions of the chuck.

Claim 8

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine comprising: a chuck for holding the wafer; means for rotating the chuck; and a grinding device including a head spaced axially from said chuck and a plurality of grinding elements spaced apart about said head, each of said grinding elements being constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of said chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck, each of said rods being in the form of strip of resilient material having a width greater than its thickness and being bent so that the directions in which the thicknesses of said shank and end portions are measured lie in a common plane, said end portion having a curved cross-section comprising a segment of a circular cylinder with the convex side thereof facing said chuck to define a grinding surface, the angle included between said shank portion and end portion of each resilient rod being greater than 90*, and the axial spacing of said head and said chuck being selected to cause said grinding surface of each of the grinding elements to be pressed resiliently against the edge of the wafer held by said chuck in all rotary positions of the chuck.

Claim 9

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine comprising: a chuck for holding the wafer; means for rotating the chuck; and a grinding device including a head spaced axially from said chuck and a plurality of grinding elements spaced apart about said head, each of said grinding elements being constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of said chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck, each of said rods being in the form of strip of resilient material having a width greater than its thickness and being bent so that the directions in which the thicknesses of said shank and end portions are measured lie in a common plane, said end portion having a curved cross-section comprising a segment of a circular cylinder with the convex side thereof facing said chuck to define a grinding surface, the angle included between said shank portion and end portion of each resilient rod being greater than 90*, and the axial spacing of said head and said chuck being selected to cause said grinding surface of each of the grinding elements to be pressed resiliently against the edge of the wafer held by said chuck in all rotary positions of the chuck.

Claim 10

The grinding machine of claim 6 in which the outer portion of said convex surface of each of said strips has grinding material electrodeposited thereon.

Claim 11

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine cmprising: a chuck for holding the wafer; means for rotating said chuck; and a grinding device including a head spaced axially from said chuck a plurality of grinding elements spaCed apart about said head, each of said grinding elements being a constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of said chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck to provide a grinding surface facing toward the wafer held by said chuck, the angle included between said shank portion and end portion of said flexibly resilient rod being greater than 90*, the axial spacing of said head and chuck being selected to cause said grinding surface of each of said grinding elements to be pressed resiliently against the edge of said wafer held by the chuck in all rotary positions of said chuck, and a resilience adjustment ring encirling and attached to said shank portion of each of said resilient rods and spaced from said head to control the flexing of said rods when said grinding surfaces of the rods are pressed against said wafer.

Claim 12

A grinding machine for grinding a predetermined edge contour on a semiconductor wafer, said machine cmprising: a chuck for holding the wafer; means for rotating said chuck; and a grinding device including a head spaced axially from said chuck a plurality of grinding elements spaCed apart about said head, each of said grinding elements being a constituted by a flexibly resilient rod having a shank portion extending from said head toward said chuck generally parallel to the axis of rotation of said chuck and an end portion extending from said shank portion generally laterally outward with respect to said axis of rotation of the chuck to provide a grinding surface facing toward the wafer held by said chuck, the angle included between said shank portion and end portion of said flexibly resilient rod being greater than 90*, the axial spacing of said head and chuck being selected to cause said grinding surface of each of said grinding elements to be pressed resiliently against the edge of said wafer held by the chuck in all rotary positions of said chuck, and a resilience adjustment ring encirling and attached to said shank portion of each of said resilient rods and spaced from said head to control the flexing of said rods when said grinding surfaces of the rods are pressed against said wafer.

Claim 13

A grinding machine for grinding a predetermined edge contour simultaneously on a plurality of semiconductor wafers, said machine comprising: A. a plurality of chucks to hold a plurality of said wafers in a substantially common plane; B. means to rotate all of said chucks simultaneously, each on its own axis; C. a plurality of grinding heads corresponding in number to the number of said chucks, each of said grinding heads comprising a plurality of resilient grinding devices attached thereto, each of said devices comprising an oblique grinding surface facing the respective wafer and extending beyond the edge thereof at an angle of less than 90* with respect to the axis of the respective chuck; D. common means to adjust the position of each of said grinding heads laterally with respect to the respective wafer; and E. common means to swing all of said grinding heads simultaneously along a lateral circular path wherein each of said heads moves in a circle substantially coaxial with the axis of its respective chuck all of said chucks being longitudinally spaced from said heads to cause said grinding surfaces to be pressed against the edge of the respective one of said wafer at all rotary positions of the respective chuck.

Claim 14

A grinding machine for grinding a predetermined edge contour simultaneously on a plurality of semiconductor wafers, said machine comprising: A. a plurality of chucks to hold a plurality of said wafers in a substantially common plane; B. means to rotate all of said chucks simultaneously, each on its own axis; C. a plurality of grinding heads corresponding in number to the number of said chucks, each of said grinding heads comprising a plurality of resilient grinding devices attached thereto, each of said devices comprising an oblique grinding surface facing the respective wafer and extending beyond the edge thereof at an angle of less than 90* with respect to the axis of the respective chuck; D. common means to adjust the position of each of said grinding heads laterally with respect to the respective wafer; and E. common means to swing all of said grinding heads simultaneously along a lateral circular path wherein each of said heads moves in a circle substantially coaxial with the axis of its respective chuck all of said chucks being longitudinally spaced from said heads to cause said grinding surfaces to be pressed against the edge of the respective one of said wafer at all rotary positions of the respective chuck.

Claim 15

The grinding machine of claim 9 in which said means to swing said grinding head comprises a plate having means therein for holding said grinding heads in position.

Claim 16

The grinding machine of claim 10 in which said means to adjust the position of said grinding heads comprises: A. A pair of main shafts, each comprising a first extension at one end laterally offset with respect to the axis of said main shaft and a second extension at the other end; B. Means attaching said plate to each of said second extensions to allow rotation rotation of said second extension with respect to said plate; C. A pair of driving gear means, each of said first extensions being attached to one of said driving gear means to be rotated thereby, each of said driving gear means comprising an eccentrically bored shaft to received a respective one of said first extensions; and d. Means to adjust the angular orientation of each of said main shafts to adjust the diameter of the circle of motion of said plate.

Claim 17

The grinding machine of claim 11 comprising, in addition, detent adjustment means between each of said gear means and the respective one of said main shafts to set the diameter of the circle of motion of said plate to specific values.

Claim 18

The grinding machine of claim 9 comprising, in addition: A. A plate having a plurality of apertures corresponding in number to the number of said chucks; B. Means to support said last-named plate to place each of said apertures in coaxial alignment with a respective one of said chucks; C. Guide means concentric with each of said apertures on said plate to locate one of said semiconductor wafers with respect tO that aperture; and D. Means to lower said plate relative to said chucks to allow said chucks to lift said semiconductor wafers therefrom.