Solar silicon wafer cutting mortar and preparation method thereof

Abstract

The invention provides solar silicon wafer cutting mortar which comprises a polyethylene glycol cutting liquid, silicon carbide micropowder and a dispersing stabilizer, wherein the dispersing stabilizer comprises a modified carbamido polymer, and the ratio of the mass sum of the polyethylene glycol cutting liquid, the silicon carbide micropowder to the mass of the modified carbamido polymer is 1: (0.02-4%). The solar silicon wafer cutting mortar provided by the invention is low in sedimentation rate and high in stability. Under the premise of not reducing the water content of the mortar, the solar silicon wafer cutting mortar is used for continuously cutting a silicon wafer twice, so that the yield of the silicon wafer is improved. The invention further provides a preparation method of the solar silicon wafer cutting mortar.

Description

technical field [0001] The invention belongs to the technical field of mortar used for silicon wafer wire cutting, and in particular relates to a solar silicon wafer cutting mortar and a preparation method thereof. Background technique [0002] In the process of wire cutting of solar silicon wafers, silicon carbide micropowder is usually added to the cutting fluid in a certain proportion, and fully dispersed, configured into a uniform and stable cutting mortar and then used for silicon wafer cutting, taking advantage of the hard characteristics of silicon carbide particles Cut the silicon rod into pieces with a sharp water chestnut. [0003] The standard water content of cutting mortar is below 0.5%. The polyethylene glycol (PEG) in the cutting fluid is easy to absorb water during the cutting process, causing the water content of the mortar after cutting twice to rise to about 3%. SiC is dispersed in The hydrophilic PEG in the mortar is adsorbed on the surface of SiC throug...

AI Technical Summary

Problems solved by technology

[0003] The standard water content of cutting mortar is below 0.5%. The polyethylene glycol (PEG) in the cutting fluid is easy to absorb water during the cutting process, causing the water content of the mortar after cutting twice to rise to about 3%. SiC is dispersed in The hydrophilic PEG in the mortar is adsorbed on the surface of SiC through hydrogen bonds. After the water content of the mortar increases, because the hydrogen bonds of water molecules are more active than the hydrogen bonds of PEG, the adsorption amount of PEG on the SiC surface will be greatly reduced, resulting in being The SiC adsorbed by water is easy to settle, and the dispersion effect of the mortar becomes poor, which affects the yield rate of silicon wafers

Therefore, it is necessary to solve the problem that the moisture in the slurry increases during the silicon wafer cutting process and affects the dispersion of SiC

[0004] There are two ways to solve this problem in the prior art: one is to reduce the moisture in the mortar by designing a moisture absorption device (such as patent documents CN 203408492U, CN 203664250U), but the desiccant used in the water absorption device is usually silica gel, and the water absorption capacity Limited; the other is to improve the dispersibility by adding additives, such as the invention CN 102093925B using polyorganic carboxylic acid dispersants to improve the dispersibility of SiC, but its dispersibility to SiC mortar systems with a water content of 2-3% is improved The space is small, and after adding an acidic dispersant, it is necessary to adjust the pH of the mortar to neutral before it can be used

Images