Systems and methods for ingot grinding
View Patent ↗A method of grinding an ingot for use in manufacturing a semiconductor or solar wafer is disclosed. The method includes providing an ingot including four flat sides and four rounded corner portions, each corner portion extending between an adjacent pair of the flat sides, and grinding a plurality of planar facets on each corner portion, each planar facet of the corner portion joined to an adjacent facet at a juncture and oriented such that each corner portion has a substantially arcuate shape. A wafer and ingot are also disclosed.
1. A wafer of solar or semiconductor material, the wafer comprising:
a plurality of flat sides; and
a corner portion extending between an adjacent pair of the flat sides, the corner portion including a plurality of planar facets, each planar facet of the corner portion joined to an adjacent facet at a juncture and oriented such that the corner portion has a substantially arcuate shape, wherein the corner portion includes a finite number of planar facets and includes at least six planar facets.
2. A wafer in accordance with claim 1 , wherein each juncture is rounded such that the corner portion has a smooth, creaseless surface formed by the finite number of planar facets.
3. A wafer in accordance with claim 1 , wherein the corner portion includes a first planar facet joined to a first flat side at a first interface and a second planar facet joined to a second flat side at a second interface, and wherein the first and second interfaces are rounded to form smooth surfaces between the corner portion and the first and second flat sides.
4. A wafer in accordance with claim 1 , wherein the wafer comprises four flat sides and four corner portions.
5. A wafer in accordance with claim 1 , wherein the wafer is made of mono-crystalline silicon.
6. A wafer in accordance with claim 1 , wherein the substantially arcuate corner portion has a radius of approximately 100 millimeters.
7. A wafer in accordance with claim 1 , wherein each of the plurality of planar facets has the same length.
8. A wafer in accordance with claim 1 , wherein the wafer has a thickness between approximately 180 and 200 micrometers.
9. A wafer in accordance with claim 1 , wherein the corner portion includes only six planar facets.
10. A wafer in accordance with claim 1 , wherein the plurality of facets are formed by grinding an ingot with at least one cup wheel, and slicing the ground ingot.
11. A wafer in accordance with claim 10 , wherein the plurality of facets are formed by grinding the ingot using both a first cup wheel with a rough grinding surface and a second cup wheel with a fine grinding surface.