CN111979033A

CN111979033A - Diamond wire cutting liquid for sapphire cutting

Info

Publication number: CN111979033A
Application number: CN202010892478.5A
Authority: CN
Inventors: 祁有丽
Original assignee: Zhongkefudi Technology Development Co ltd
Current assignee: Zhongkefudi Technology Development Co ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-11-24
Anticipated expiration: 2040-08-31
Also published as: CN111979033B

Abstract

The invention discloses diamond wire cutting liquid for sapphire cutting, and relates to the technical field of processing of semiconductor hard and brittle materials. The invention discloses diamond wire cutting fluid for sapphire cutting, which consists of the following components in percentage by weight: 35-55% of deionized water, 10-20% of water-soluble lubricant, 15-20% of wetting penetrant, 5-10% of water-soluble antirust agent, 3-6% of coupling agent, 10-15% of base number retaining agent, 3-5% of complexing agent and 0.5-1.5% of defoaming agent. The diamond wire cutting liquid for sapphire cutting provided by the invention is suitable for a diamond wire multi-wire cutting process, the dilution rate is 20-30 times when the diamond wire cutting liquid is used, the diamond wire cutting liquid has good lubricity, cooling property, dispersibility, cleaning property, antirust property and foam stability in the using process, the slicing yield reaches 99%, and the wire marks, TTV values and edge breakage conditions on the surface of a sapphire wafer can be effectively reduced.

Description

Diamond wire cutting liquid for sapphire cutting

Technical Field

The invention belongs to the technical field of processing of semiconductor hard and brittle materials, and particularly relates to diamond wire cutting fluid for sapphire cutting.

Background

Sapphire has increasingly wide application in the fields of LED substrates, window sheets and national defense due to a series of excellent physicochemical characteristics of high melting point (2050 ℃), high hardness (second to diamond), high temperature resistance, friction resistance, corrosion resistance, chemical stability, good light transmittance, electric insulation and the like. For example, as a substrate for growing a light emitting diode, a sapphire wafer is basically used as a substrate for a light emitting diode used in a domestic LED lamp. With the continuous penetration of the artificial intelligence field in various fields, the application of sapphire as a window sheet is more and more extensive. Such as a mobile phone camera, a mobile phone screen, a watch mirror surface, various cash register devices, a window needing good light transmission and skid resistance, and the like. In the field of national defense, sapphire crystals are important window materials for infrared military devices, missiles, submarines, satellite space technologies, high-energy detection and high-power strong lasers. According to statistics, the LED consumed 77.23% of the global sapphire capacity in 2015, and then mobile phone glass, camera lens, watch and the like. At present, the LED substrate material is the first large application field of sapphire, and consumer electronics applications represented by smart phones and the like are the market potential of sapphire materials in the future.

The LED chip is used as the first large application field of sapphire, and has important influence on the development of the sapphire industry. The growth of the LED material needs to manufacture a gallium nitride (GaN) -based epitaxial wafer on a substrate, the growth process is mainly completed in a Metal Organic Chemical Vapor Deposition (MOCVD) epitaxial furnace, commonly used substrates mainly comprise sapphire, silicon carbide and silicon substrates, and the sapphire material occupies an absolute mainstream position of the substrate material by virtue of the advantages of good epitaxial lattice matching and high cost performance. The quality of the sapphire wafer has great influence on the growth quality of the gallium nitride epitaxial wafer and the performance and yield of the blue light diode. The first choice for high quality LED products is to ensure the quality of the substrate chip. Sapphire crystal bars are processed into window sheets, substrates and the like with required precision by slicing, chamfering, grinding, surface flattening and surface treatment technologies. Slicing is a preliminary stage of sapphire processing and is one of the most critical steps affecting subsequent wafer quality. Sapphire processing starts late in China, and a slicing process mainly refers to a process technology for referencing semiconductor silicon wafers, but the sapphire processing and the slicing process are essentially different. As the photovoltaic industry and the ultra-large integrated circuit industry require thinner and thinner silicon chips, the number of the abrasive materials per unit surface area of the diamond wire for cutting silicon is far greater than that of the diamond wire for cutting sapphire. Thus, while belonging to the category of diamond wire multi-wire dicing, the processing parameters and the quality of the wafer surface for the two different materials are completely different. The literature patent reports more about silicon wafer cutting. Mainly relates to multi-line cutting from original steel wire mortar cutting to diamond wires. However, research papers and patents about diamond wire cutting fluid for sapphire wafers are rarely reported.

Patent CN201810249891.2 reports a diamond wire cutting fluid for cutting silicon wafers, the invented cutting fluid has excellent lubricating and cooling properties; patent CN109370760A reports a high-lubrication high-dilution-ratio diamond wire cutting liquid and preparation thereof, the diamond wire cutting liquid provided by the invention is a high-dilution-ratio diamond wire cooling liquid developed according to the requirements that silicon wafers in the photovoltaic industry are thinner and the processing cost is lower and lower, and the product is a mainstream product in the current silicon wafer cutting industry and has excellent cooling performance and foam inhibition capability. Patent CN201710345871 reports a low-foam water-based diamond wire cutting liquid, mainly utilizes a low-foam polyether and polyether modified siloxane formula system, invents the low-foam diamond wire cutting liquid, and solves the problems that a large amount of small-size silicon powder is easy to agglomerate when a silicon wafer is cut, so that a large amount of foam is accumulated and cannot disappear in time, the wetting dispersibility of the system is reduced, and finally the surface of the silicon wafer is cracked, line marks and other bad phenomena. However, since the hardness of silicon is different from that of sapphire, and the required thickness of a silicon wafer is different from that of a sapphire wafer, the size and number of surface abrasives of diamond wires used, and the diameter of the wires are different from each other, and thus, the diamond wire cutting fluid for cutting silicon wafers is not suitable for cutting sapphire wafers. With the popularization of 5G and the development of OLED and micro LED technologies, the application of sapphire wafers in China is more and more extensive, and therefore the requirement on sapphire wafer processing technology is higher and higher. However, as a result of research on documents and patent queries, domestic studies on diamond-wire cutting fluid products for sapphire cutting are rarely reported, and studies on the influence of sapphire diamond-wire cutting fluid compositions on TTV, BOW and WARP values of wafers are not found.

The diamond wire cutting fluid is an important component of diamond wire cutting and has the following properties: (1) the lubricating property is that cutting fluid permeates into the surface of the diamond wire and the surface of the sapphire, and in the high-speed cutting process of the diamond wire, the lubricant in the formula plays a role in reducing friction on the surface of a friction pair in relative motion, so that cutting damage, stress and microcrack are reduced; (2) the wetting dispersion effect and the good wetting property are beneficial to improving the cooling effect of the cutting fluid, and the heat generated by high-speed cutting can be transferred out through the circulating cutting fluid, so that the deformation of the surface of the wafer is avoided. The good wetting dispersibility can enable a large amount of sapphire powder generated in the cutting process to be dispersed and suspended in the cutting liquid in time, and the problems of broken lines, surface scratches, foams and the like caused by particle aggregation are prevented. (3) The diamond wire cutting machine has the advantages that the abrasive on the surface of the diamond wire can fall off in the cleaning effect and a large amount of sapphire powder is formed, and fine particles are easy to agglomerate due to high surface energy, so that the TTV value, the WARP value and the BOW value which reflect the surface quality of a wafer are large, the quality of the wafer cannot meet the requirements, and the abrasion of the diamond wire cutting machine is large. The cutting fluid with good cleaning performance can take away the sapphire powder gathered on the surface of the wafer and the fallen diamond wire grinding material at any time. (4) The antirust effect is that the main material of the machine tool is ferrous metal, and a large amount of cutting fluid continuously washes the machine tool in the multi-line cutting process to be easily corroded. The antirust property of the cutting fluid can effectively prevent the machine tool machining precision from being reduced due to corrosion, and the service life of the machine tool is shortened.

In the prior art, the sapphire wafer is still processed by using the cutting fluid for cutting the silicon wafer. In fact, the diamond wire unit area abrasive used for cutting the sapphire wafer is much smaller than that of the diamond wire surface used for cutting silicon, and the thickness of the sapphire wafer is much larger than that of the silicon wafer. Therefore, for sapphire cutting, a cutting fluid having higher extreme pressure lubricity, a lower friction coefficient, and better dispersion wettability is required. The invention aims to provide diamond wire cutting liquid specially used for cutting sapphire wafers, and the diamond wire cutting liquid can meet the requirement of multi-wire cutting of the sapphire wafers at present.

Disclosure of Invention

The invention aims to provide diamond wire cutting fluid for sapphire cutting, which has excellent lubricating, cooling, permeating, cleaning and antirust performances, is safe and environment-friendly, has stable physical and chemical properties and high cost performance, replaces imported products, and effectively reduces the processing cost of enterprises.

In order to achieve the purpose of the invention, the invention provides diamond wire cutting fluid for sapphire cutting, which consists of the following components in percentage by weight: 35-55% of deionized water, 10-20% of water-soluble lubricant, 15-20% of wetting penetrant, 5-10% of water-soluble antirust agent, 3-6% of coupling agent, 10-15% of base number retaining agent, 3-5% of complexing agent and 0.5-1.5% of defoaming agent.

Further, the molecular structure of the water-soluble lubricant has long-chain alkyl groups, namely one or more of polyethylene glycol orthosilicate, polyethylene glycol oleate monoester, polyethylene glycol oleate diester, dimer acid amide, potassium dimer, ammonium metasilicate, ammonium ricinoleate and ammonium tetrameric ricinoleate.

Further, the water-soluble antirust agent is one or more of sebacic acid, neodecanoic acid, tribasic acid and N-amide aminocaproic acid.

Further, the wetting penetrating agent is one or more of EO/PO block polyoxyethylene ether, polyoxyethylene and penetrating agent JFC.

Further, the coupling agent is one or more of diethylene glycol monobutyl ether, C16 Guerbet alcohol, isopropanol, C6-C8 alkyl glycoside surfactant and sodium isophenylsulfonate.

Further, the alkali retention agent is one or more of monoethanolamine, monoisopropanolamine, triethanolamine and diglycolamine.

Further, the complexing agent is one or more than two of sodium tripolyphosphate, potassium pyrophosphate, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylamine triacetic acid, ethylene glycol-bis- (B-aminoethyl ether) -N, N-tetraacetic acid, methyl glycine diacetic acid trisodium and EDTA disodium.

Further, the defoaming agent is one or more of organic silicon modified polyether esters, high-carbon alcohols and alkynol defoaming agents.

The invention achieves the following beneficial effects:

1. the diamond wire cutting fluid for sapphire processing is suitable for a diamond wire multi-wire cutting process, the dilution rate is 20-30 times when the diamond wire cutting fluid is used, and the diamond wire cutting fluid has good lubricity, cooling property, dispersibility, cleaning property, rust resistance and foam stability in the using process.

2. The diamond wire cutting fluid is used for processing the sapphire wafer, so that the slicing yield reaches 99%, and the wire mark, TTV value and edge breakage condition on the surface of the sapphire wafer can be effectively reduced.

3. The diamond wire cutting fluid for sapphire processing can effectively prolong the service life of diamond wires, improve the quality of wafers, improve the yield of the wafers from 95.24 percent to 99.01 percent, greatly reduce the cost of enterprises in the aspect of processing the sapphire wafers, and provide the sapphire wafers with reliable quality for the epitaxial growth of gallium nitride.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A diamond wire cutting fluid for sapphire cutting is composed of the following components in percentage by weight:

35-55% of deionized water;

10 to 20 percent of water-soluble lubricant,

15 to 20 percent of wetting penetrant,

5 to 10 percent of water-soluble antirust agent,

3 to 6 percent of coupling agent,

10 to 15 percent of alkali value retention agent,

3 to 5 percent of complexing agent,

0.5-1.5% of defoaming agent.

Wherein, the molecular structure of the water-soluble lubricant has long carbon chain alkyl, namely one or more of polyethylene glycol orthosilicate, polyethylene glycol oleate monoester, polyethylene glycol oleate diester, dimer acid amide, potassium dimer, ammonium metasilicate, ammonium ricinoleate and ammonium tetrapolymer ricinoleate;

the wetting penetrating agent is one or more of EO/PO block polyoxyethylene ether, polyoxyethylene and penetrating agent JFC;

the water-soluble antirust agent is one or more of sebacic acid, neodecanoic acid, tribasic acid and N-amido caproic acid;

the coupling agent is one or more of diethylene glycol monobutyl ether, C16 Guerbet alcohol, isopropanol, C6-C8 alkyl glycoside surfactant and sodium isophenylsulfonate;

the alkali retention agent is one or more of monoethanolamine, monoisopropanolamine, triethanolamine and diglycolamine;

the complexing agent is one or more than two of sodium tripolyphosphate, potassium pyrophosphate, diethylene triamine pentaacetic acid, N-hydroxyethyl ethylamine triacetic acid, ethylene glycol-bis- (B-aminoethyl ether) -N, N-tetraacetic acid, methyl glycine diacetic acid trisodium (MGDA) and EDTA disodium;

the defoaming agent is one or more of organic silicon modified polyether esters, high-carbon alcohols and alkynol defoaming agents.

The diamond wire cutting fluid for sapphire cutting of the present invention will be described with reference to specific embodiments.

Example 1:

an enamel blending kettle is started for pulse stirring, 30 kg of deionized water is added, 3 kg of complexing agent methyl glycine diacetic acid trisodium (MGDA), 15 kg of alkali retention agent triethanolamine, 15 kg of diglycolamine and 7 kg of water-soluble antirust agent dodecanedioic acid are sequentially added, and when the added alcohol amine and the antirust agent completely react, the system is a transparent solution. And sequentially adding 20 kg of water-soluble lubricant potassium dimer, 5 kg of wetting penetrant fatty alcohol-polyoxyethylene ether, 5 kg of coupling agent C16 Guerbet alcohol and 0.5 kg of polyether modified siloxane defoamer, stirring until the whole system is transparent and uniform, detecting key indexes such as foam, lubricity, friction coefficient, surface tension, permeability and the like, and taking out of a kettle and packaging by a plastic barrel. Example 1 the test data are shown in table-1.

Example 2

Starting an enamel mixing kettle for pulse stirring, adding 40 kg of deionized water, then sequentially adding 3 kg of complexing agent EDTA disodium salt, 12 kg of alkaline maintainer triethanolamine, 12 kg of diglycolamine, and 10 kg of water-soluble antirust agent sebacic acid, and reacting the added alkanolamine with the antirust agent completely, wherein the system is a transparent solution. Then adding 15 kg of water-soluble lubricant oleic acid polyethylene glycol 400 diester, 4 kg of water-soluble penetrant JFC, 3 kg of couplant diethylene glycol monobutyl ether and 1 kg of polyether modified siloxane defoamer in sequence, stirring until the whole system is transparent and uniform, detecting key indexes such as foam, lubricity, friction coefficient, surface tension, permeability and the like, and taking out of a kettle and packaging with a plastic barrel. Example 2 the test data are shown in table-1.

Example 3

An enamel blending kettle is started for pulse stirring, 42 kg of deionized water is added, then 3 kg of complexing agent sodium tripolyphosphate, 2 kg of Diethylene Triamine Pentaacetic Acid (DTPA), 10 kg of alkali retention agent triethanolamine, 8 kg of monoethanolamine, 5 kg of water-soluble antirust agent tribasic acid and 2 kg of n-capric acid are sequentially added, and when the added alkanolamine and the antirust agent completely react, the system is a transparent solution. Then sequentially adding 5 kg of water-soluble lubricant ammonium tetrapolyricinoleate, 13 kg of lauric acid polyethylene glycol 600 ester, 5 kg of water-soluble penetrant EO/PO block polyoxyethylene ether, 4.5 kg of coupling agent sodium isophenylsulfonate and 0.5 kg of alkynol defoamer, stirring until the whole system is transparent and uniform, detecting key indexes such as foam, lubricity, friction coefficient, surface tension, permeability and the like, and taking out of a plastic barrel for packaging. Example 3 the test data are shown in table-1.

Example 4

An enamel blending kettle is started for pulse stirring, 43 kg of deionized water is added, 4 kg of complexing agent potassium pyrophosphate, 3 kg of ethylene glycol-bis- (B-aminoethylether) -N, N-tetraacetic acid, 10 kg of alkali retention agent triethanolamine, 10 kg of monoisopropanolamine and 6 kg of aqueous antirust agent N-acylamino acid are sequentially added, and when the added alcohol amine and the antirust agent completely react, the system is a transparent solution. Then adding 15 kg of water-soluble lubricant dimer acid amide, 3 kg of C6-C8 alkyl glycoside surfactant, 5 kg of couplant diethylene glycol monobutyl ether and 1 kg of polyether modified siloxane defoamer in sequence, stirring until the whole system is transparent and uniform, detecting key indexes such as foam, lubricity, friction coefficient, surface tension, permeability and the like, and taking out of a kettle and packaging with a plastic barrel. The measurement indexes of example 4 are shown in Table-1.

Example 5

Starting an enamel blending kettle for pulse stirring, adding 50 kg of deionized water, then sequentially adding 5 kg of complexing agent EDTA-2Na, 12 kg of triethanolamine as an alkali retention agent, 8 kg of monoethanolamine, 5 kg of tribasic acid as a water-soluble antirust agent and 3 kg of neodecanoic acid, and reacting the added alkanolamine with the antirust agent completely until the system is a transparent solution. Then adding 5 kg of water-soluble lubricant oleic acid polyethylene glycol 600 monoester, 5 kg of dipotassium, 3 kg of water-soluble penetrating agent JFC, 3 kg of coupling agent C16 Guerbet alcohol and 1 kg of polyether modified siloxane defoaming agent in sequence, stirring until the whole system is transparent and uniform, detecting key indexes such as foam, lubricity, friction coefficient, surface tension, permeability and the like, and taking out of a kettle and packaging with a plastic barrel. The measurement indexes of example 5 are shown in Table-1.

Key technical indexes of the sapphire diamond wire cutting fluid are detected, and the technical indexes of comparison data between the embodiment 1-5 and products corresponding to the current local brands are shown in a table-1.

TABLE-1 Performance indices of examples 1-5 and comparative examples

According to the test results in table-1, three representative gates of the above examples 1, 3 and 5 were selected for the cutting fluid of sapphire diamond wire, and the properties can represent the cutting fluids of all formulations related to the present invention. Slicing was performed at a sapphire processing enterprise and compared with imported products currently used by the enterprise, and the results are shown in table-2.

Table 2 performance testing of diamond wire cutting fluid and comparative cutting fluid of the present invention

From the comparative test results in table-2, it can be seen that the diamond wire cutting fluid for sapphire cutting provided by the invention has the following advantages compared with the existing imported products:

(1) the product has excellent lubricating property, the service life of the diamond wire is effectively prolonged, the diamond wire cutting liquid of the original imported brand cuts a four-inch sapphire wafer, 1111 pieces of wire can be cut by ten thousand meters of wire, namely the average length of the wire required for cutting one piece is 9 meters, 1233 pieces of wire can be cut by ten thousand meters of the diamond wire cutting liquid designed by the invention, and the average length of each piece of the required diamond wire is 8.11 meters.

(2) The product has longer service life, the cutting fluid in the provided embodiment can be recycled for 6 times, and the fluid is replaced when the current imported brand is used for 5 times. The service life of the cutting fluid is prolonged, so that the use amount and the cost of subsequent wastewater treatment can be effectively reduced.

(3) The sapphire diamond wire cutting fluid designed by the invention has good wetting dispersibility and lubricity, so that the qualification rate of wafers is effectively improved compared with imported products.

The invention can combine the cutting process and parameter requirements of sapphire site, build formula with pertinence, and endow the product with excellent lubrication, cooling, infiltration and cleaning performance. The sapphire cutting fluid provided by the invention is safe and environment-friendly, has stable physical and chemical properties and high cost performance, replaces imported products, and effectively reduces the cost of processing plants of certain enterprises.

The formula of the invention is green and environment-friendly, and does not contain chemicals which have harmful effects on human bodies, soil, water sources and atmosphere. The waste cutting fluid can be precipitated and filtered to remove solid waste residues, can be directly discharged and meets the requirements of environmental protection regulations.

The technical features of the embodiments described above can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. The diamond wire cutting fluid for sapphire cutting is characterized by comprising the following components in percentage by weight: 35-55% of deionized water, 10-20% of water-soluble lubricant, 15-20% of wetting penetrant, 5-10% of water-soluble antirust agent, 3-6% of coupling agent, 10-15% of base number retaining agent, 3-5% of complexing agent and 0.5-1.5% of defoaming agent.

2. A diamond wire cutting fluid for sapphire cutting according to claim 1, wherein the water-soluble lubricant has a molecular structure in which long-chain alkyl groups, i.e., one or more of polyethylene glycol ester of lauric acid, polyethylene glycol monoester of oleic acid, polyethylene glycol diester of oleic acid, dimer acid amide, potassium dimer acid, amine salt of lauric acid, ammonium salt of ricinoleic acid, and ammonium salt of tetrapoly ricinoleic acid, are present.

3. The diamond wire cutting fluid for sapphire cutting as claimed in claim 1, wherein the water-soluble antirust agent is one or more of sebacic acid, neodecanoic acid, tribasic acid and N-amide aminocaproic acid.

4. The diamond wire cutting fluid for sapphire cutting as claimed in claim 1, wherein the wetting penetrant is one or more of EO/PO block polyoxyethylene ether, polyoxyethylene and penetrant JFC.

5. A diamond wire cutting fluid for sapphire cutting as claimed in claim 1, wherein the coupling agent is one or more of diethylene glycol monobutyl ether, C16 Guerbet alcohol, isopropanol, alkyl glycoside surfactant of C6-C8, and sodium isophenylsulfonate.

6. A diamond wire cutting fluid for sapphire cutting according to claim 1, wherein the alkali retention agent is one or more of monoethanolamine, monoisopropanolamine, triethanolamine and diglycolamine.

7. A diamond wire cutting fluid for sapphire cutting according to claim 1, wherein the complexing agent is one or more of sodium tripolyphosphate, potassium pyrophosphate, diethylenetriamine pentaacetic acid, N-hydroxyethylethylamine triacetic acid, ethylene glycol-bis- (B-aminoethyl ether) -N, N-tetraacetic acid, trisodium methylglycinediacetic acid, and disodium EDTA.

8. A diamond wire cutting fluid for sapphire cutting as claimed in claim 1, wherein the defoaming agent is one or more of silicone modified polyether esters, high carbon alcohols and alkynol defoaming agents.