Chemical recovery method for mortar in wire cutting technology

Abstract

The invention relates to a recovery method for mortar in a wire cutting technology, in particular to a chemical recovery method for the mortar in the wire cutting technology. The chemical recovery method comprises the following operation steps: firstly, solid-liquid separation is carried out on the mixed mortar containing cutting liquid A, silicon powders, metal filings and silicon carbide abrasives after wire cutting to obtain a liquid part B and a solid part C; secondly, the silicon powders and the metal filings in the solid part C are removed by adopting a chemical treatment method to obtain a solid part D which is rich in the silicon carbide abrasives; and thirdly, the solid part D which is rich in the silicon carbide abrasives is directly and uniformly stirred with cutting liquid E to obtain mixed materials G, and the mixed materials G are used for wire cutting again. The invention removes metal impurities and the silicon powders, can be used for secondary cutting without drying the silicon carbide abrasives, and enables the silicon carbide abrasives and water soluble cutting liquid to be repeatedly and reasonably utilized. The use effect of recovered mortar is nearly same with the use effect of new mortar, therefore, the cost of chemical recovery of the mortar is greatly lowered.

Description

technical field [0001] The invention relates to a method for recovering mortar in a wire cutting process, in particular to a chemical recovery method for mortar in a wire cutting process. Background technique [0002] In the processing of silicon wafers, cutting silicon rods or blocks into sheets of different diameters and thicknesses through special wire cutting equipment is currently a common processing method in the world. The cutting principle is to use thousands of steel wires with a diameter of about 120-160 μm as the cutting carrier, use silicon carbide abrasives whose hardness is second only to diamond as the main cutting medium, and use silicon carbide abrasives with good wettability, strong cutting ability and strong resistance to silicon carbide Cutting fluids such as polyethylene glycol-based, propylene glycol-based or oil-based suspensions with excellent dispersing properties are used as dispersants for silicon carbide abrasives to prepare mortars that are unifo...

AI Technical Summary

Problems solved by technology

Although this mortar recycling system solves the problem of mortar recycling to a certain extent, there are other defects: the method adopted by this recycling system cannot remove the metal impurities in the old mortar and the silicon powder attached to the surface of the silicon carbide abrasive, so after The recovered mortar cannot be directly recycled, and a certain proportion of new silicon carbide abrasives must be added to be used for wire cutting again. At the same time, the wire cutting process becomes unstable when it is used again due to the presence of metal impurities and silicon powder. The surface quality of the chip is reduced, and the scrap rate is high

Affected by this concept, the existing literature reports believe that the recycling of silicon carbide abrasives also needs to be dried to avoid poor uniform dispersion.

Images