Method for production of photovoltaic wafers and abrasive slurry
AssigneeRec Solar Pte. Ltd.
InventorsMohan Menon, Anne Lohne, Erik Sauar, Stian Sannes
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Abstract
The present invention relates to a method for production of photovoltaic wafers and abrasive slurries for multi-wire sawing of wafers for photovoltaic applications, and more specific to abrasive slurries which are easy to remove from the wafers after sawing, where the abrasive slurry comprises one part recycled abrasive slurry, an alkali in sufficient amount to provide a pH in the abrasive slurry mixture in the range from 6.0 to 9.0, and one part novel abrasive slurry in an amount sufficient to provide an ion content in the abrasive slurry mixture to provide an electric conductivity of less than 50 μS/cm.
Claims4
Abrasive slurry mixture for use in wire sawing of photovoltaic wafers, wherein the abrasive slurry mixture comprises:
- one part recycled abrasive slurry,
- one part alkali, and
- one part novel abrasive slurry in an amount sufficient to provide an ion content in the abrasive slurry mixture to provide an electric conductivity of less than 50 μS/cm and a pH in the abrasive slurry mixture in the range from 6.0 to 9.0,
- wherein the abrasive slurry being employed is a polar organic liquid with free abrasive particles, and
- the polar organic liquid is one or more of the following liquids;
- polyethylene glycol (PEG), polypropylene glycol (PPG), co polymers of various polyalkylene oxides, and polyalkylene glycol (PAG), and
- the free abrasive particles are one or more of the following abrasive particles;
- aluminium oxide (corundum), silicon carbide (SiC), boron carbide (BC), and gallium carbide.
Dependencies are inferred from the claim text.