**First, excellent products ** 1: The silicon surface is smooth and clean.

2: TV: 220Â±20 Î¼m.

3: Geometry:

Side length 125 Â± 0.5mm; diagonal 150 Â± 0.5mm, 148 Â± 0.5mm, 165 Â± 0.5mm;

Side length 103 Â± 0.5mm, diagonal 135 Â± 0.5mm;

Side length 150Â±0.5mm, 156Â±0.5mm, diagonal 203Â±0.5mm, 200Â±0.5mm.

Concentricity: The difference between the chord lengths of any two arcs is â‰¤ 1 mm.

Verticality: The angle between any two sides: 90Â°Â±0.3.

**Second, qualified products ** First grade:

1: There is a little stain on the surface, slight line marks.

2:220Â±20 Î¼m â‰¤TVâ‰¤220Â±30 Î¼m.

3: Geometry:

Side length 125 Â± 0.5mm; diagonal 150 Â± 0.5mm, 148 Â± 0.5mm, 165 Â± 0.5mm;

Side length 103 Â± 0.5mm, diagonal 135 Â± 0.5mm;

Side length 150Â±0.5mm, 156Â±0.5mm, diagonal 203Â±0.5mm, 200Â±0.5mm.

Concentricity: The difference between the chord lengths of any two arcs is â‰¤1.2mm.

Verticality: The angle between any two sides: 90Â°Â±0.5.

Secondary product:

1: The surface has a few stains, line marks, dents, and slight collapse.

2: 220Â±30 Î¼m â‰¤TVâ‰¤220Â±40 Î¼m.

3: Dent: The sum of the dents on the surface of the silicon wafer is â‰¤ 30 Î¼m.

4: collapse range: collapse port is not triangular shape, collapse port length â‰¤ 1mm, depth â‰¤ 0.5mm

5: Geometry:

Side length 125 Â± 0.52mm; diagonal 150 Â± 0.52mm, 148 Â± 0.52mm, 165 Â± 0.52mm;

Side length 103 Â± 0.52mm, diagonal 135 Â± 0.52mm;

Side length 150Â±0.52mm, 156Â±0.52mm, diagonal 203Â±0.52mm, 200Â±0.52mm.

Concentricity: The difference between the chord lengths of any two arcs is â‰¤ 1.5 mm.

Verticality: The angle between any two sides: 90Â° Â± 0.8.

Three best products:

1: There is oil on the surface but the color of silicon wafer is not black, and the line marks and silicon fall off.

2:220Â±40 Î¼m â‰¤TVâ‰¤220Â±60 Î¼m.

3: Silicon falling: The entire silicon wafer is detached from the edge of the silicon crystal or part of the silicon crystal falls off.

**Third, unqualified products ** Severe line marks, thick flakes: TV>220Â±60 Î¼m.

Flaps: Silicon wafers with defects that can be changed to Î¦103.

Air hole piece: There are perforations in the middle of the silicon piece.

Profiles: Cut square round silicon wafers that have not been ground.

Chamfers (concentricity): The difference between the chord lengths of any two arcs is >1.5mm.

Diamond plate (perpendicularity): The angle between any two sides is >90Â°Â±0.8.

Indentation: The sum of the dents on both sides of the wafer is >30 Î¼m.

Dirty film: The surface of the wafer is heavily stained and yellowish black.

Deviation of size: The geometric size exceeds the range of secondary products.

Note: The silicon thickness for the above standard is 220Î¼m.

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