Metal silicon ingots

Description

First class:
1: surface is a little stain, slight line mark.
"0 + *0 microns or less TV **0 plus or minus *0 microns or less.
Second:
1: surface is a little stain, the line mark, dent, slight edge collapse.
2:*****0 microns or less TV **0 + *0 microns or less.
The sum of 3: dent: silicon wafer surface dent *0 microns or less.
4: side damage range: collapse edge of mouth is not a triangular shape, collapse edge length of 1 mm or less, the depth of 0.5 mm or less
Level 3:
1: the surface of the oil but silicon color is not black, cable lines and the silicon fall phenomenon.
"0 + *0 microns or less TV **0 + *0 microns or less.
3: silicon falls: the entire silicon fall off or edges of a silicon wafer silicon fall off.