CN102784977A - Silicon crystal line cutting fluid - Google Patents
Silicon crystal line cutting fluid Download PDFInfo
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- CN102784977A CN102784977A CN201210267898XA CN201210267898A CN102784977A CN 102784977 A CN102784977 A CN 102784977A CN 201210267898X A CN201210267898X A CN 201210267898XA CN 201210267898 A CN201210267898 A CN 201210267898A CN 102784977 A CN102784977 A CN 102784977A
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Abstract
The invention relates to a silicon crystal line cutting fluid, which comprises the following components by mass percentage: 60-70 percent of dispersing agent by weight, 8-12 percent of organic base by weight, 4-6 percent of surfactant by weight, 2-6 percent of defoamer by weight, 1-3 percent of chelating agent by weight, and 3-25 percent of deionized water by weight. Polyethylene glycol 400 is adopted as the dispersing agent, diethanolamine is adopted as the organic base, dimethyl silicone oil is adopted as the defoamer, sodium dodecylbenzene sulfonate is adopted as the surfactant, and disodium edentate is adopted as the chelating agent. The line cutting fluid has an appropriate pH value, appropriate viscosity and better lubrication permeability. Moreover, the line cutting fluid has a higher suspension rate for SiC abrasive grains. Tests show that the line cutting fluid has a higher material removal rate for silicon crystals, surface roughness and damage of silicon wafers can be reduced effectively, and metal ion contamination can be eliminated.
Description
Technical field
The present invention relates to the crystal-cut technical field, especially relate to a kind of cutting liquid that is used to cut silicon crystal.
Background technology
Along with the develop rapidly of global solar and microelectronic industry, the demand of silicon chip is increased fast.Section is the first road critical process of silicon chip processing, also is simultaneously to cause silicon chip stress, top layer and subsurface stratum damage and collapse one of the master operation on limit.Stress can cause the silicon chip breakdown voltage to descend and leakage current increases, and the existence of stress simultaneously can cause dislocation, makes carrier lifetime reduce, and the amplification coefficient of device dwindles; The damage of surface and subsurface stratum can increase the following process difficulty, reduces working (machining) efficiency, improves processing cost.Along with development of modern industry, the machining accuracy and the efficient of silicon chip are had higher requirement, strengthen the research of the silicon crystal microtomy development for China's semiconductor and solar energy industry is significant.
Multi-thread cutting technique is a kind of novel crystalline material microtomy that occurs the nineties in 20th century; Its principle is that a steel wire is entangled between the retractable line wheel through a series of guide wheels; And by the regulating wheel tensioning, finally be wrapped in the parallel nets that formation is uniformly distributed with on several working rolls, and workpiece is done the to-and-fro thread motion relatively; The abrasive material (diamond or SiC) that is suspended in the cutting liquid is driven the cutting zone attrition process; Simultaneously, workpiece is perpendicular to the gauze radial feed, disposablely cuts out a large amount of wafers.The researcher has done number of research projects to multi-thread cutting technique both at home and abroad; The result show with tradition in circle cutting compare; Characteristics such as multi-thread cutting has the production efficiency height, the joint-cutting loss is little, surface damage is little, stress is little, machining accuracy height are more suitable for the cutting processing of following major diameter thin slice.Scroll saw is cut the thick high conformity of silicon chip sheet, and easily abrasive forming has effectively reduced inferior rate, and the scroll saw system is flexible diced system, stressed evenly, give the littler cutting residual stress of silicon chip, surface and subsurface stratum damage little in the cutting process.Through grinding and polishing, remove damage layer and micro-crack than being easier to, reduced the fragment possibility in the later process process of circulation effectively.
Numerous researchs show, under the stable situation of wire cutting technology, the performance of cutting liquid is one of key factor that influences silicon chip cutting efficiency and quality.In the cutting process; Cutting liquid is processed with machinery and chemical dual effect to silicon crystal; Can play lubrication, the strong mechanical friction between steel wire, abrasive particle and silicon material is converted into the intermolecular interior friction of lubricating film, make the friction pair motion steadily; Reduce damage and stress, in time taken away the heat that cutting process produces simultaneously; But also can play cleaning action, and under the prerequisite of environmental protection, improve the rust resistance and corrosion resistance performance of lathe.Well behaved cutting liquid requires nontoxic, soluble in water, the easy cleaning of its composition, little, the ability biodegradation and functional at aspects such as lubricated infiltration, dispersion suspensions of volatility.Cutting fluid power with characteristics such as good lubrication permeability, abrasive particle are uniformly dispersed, the pH value is suitable enough greatly reduces the loss of silicon material when cutting, effectively reduces the silicon chip surface damaging stress, reduces cutting damage layer, improves silicon chip machining accuracy and quality.
At present, existing both at home and abroad multiple wire cutting liquid shaped article, but its prescription belongs to the rare report of trade secret.Cutting liquid is monopolized by offshore company for a long time, and cost is high, and domestic homemade cutting liquid hanging wire poor-performing; The dispersion suspension poor performance, surface adsorption is serious, is unfavorable for cleaning; There is more metal ion pollution; Mechanism is strong excessively in the cutting process, causes surface damage and residual stress bigger etc., causes not ideal enough the having much room for improvement of silicon chip quality that cuts out.
Summary of the invention
To the problems referred to above that prior art exists, the applicant provides a kind of silicon crystal wire cutting liquid.This wire cutting liquid has suitable pH value, viscosity and lubricated preferably permeability; And the SiC abrasive particle had high suspensibility, through overtesting, it has higher material removal rate to silicon crystal; Silicon chip surface roughness and damage can be effectively reduced, and the pollution of metal ion can be removed.
Technical scheme of the present invention is following:
A kind of silicon crystal wire cutting liquid, the mass percent of its component and each component is following: dispersant 60 ~ 70 wt%, organic base 8 ~ 12 wt%, surfactant 4 ~ 6wt%, antifoaming agent 2 ~ 6 wt%, chelating agent 1 ~ 3 wt%, deionized water 3 ~ 25 wt%.
Said dispersant is a polyethylene glycol; Said organic base is a hydramine alkali; Said surfactant is an anion surfactant; Said antifoaming agent is a silicone oil.Said polyethylene glycol is a PEG400, and said hydramine alkali is diethanol amine, and said silicone oil is dimethicone, and said anion surfactant is a neopelex.Said chelating agent is a disodium ethylene diamine tetraacetate.
The preparation method of said cutting liquid is: get dispersant, under stirring condition, add deionized water, make it to dissolve each other fully with dispersant; And then the adding organic base, stir, and then add antifoaming agent; Add surfactant and chelating agent at last, stirring gets final product.
The mixing quality of prepared wire cutting liquid and abrasive material (the green SiC of 800#) is than being 1:0.6 ~ 1, preferred 1:0.8.
Beneficial technical effects of the present invention is:
The collocation of each raw material components of wire cutting liquid of the present invention and selection are through well-designed, thereby have the good technical effect:
(1) employed dispersant polyethylene glycol is a nonionic among the present invention, can be adsorbed on the SiC grain, and is sterically hindered in the generation of SiC grain, helps the even dispersion of SiC abrasive particle, can effectively hinder reunion; The surfactant neopelex is an anionic; Except having extraordinary cleaning dirt-removing power; The anionic activating agent can also be adsorbed in grain makes abrasive particle repel each other because of having like charges, improves dispersed also obstruction of abrasive particle and reunites.So under the neopelex acting in conjunction of the polyethylene glycol of nonionic and ion-type; Can make grain produce sterically hindered and Zeta electric potential simultaneously; As shown in Figure 1; Because the acting in conjunction that grain barrier potential and electricity are built can more effectively increase the dispersion suspension performance of abrasive particle, this is that this present invention has one of major reason of the buoyancy of uphanging.
(2) detergency ability of neopelex can reduce with hardness of water among the present invention; Therefore adopt deionized water to reduce hardness ions content in the water; And add an amount of chelating agent composition; Metal ion in the complexing cutting liquid can reduce hardness of water under the double action greatly, thereby improves the cleaning dirt-removing power of neopelex.So under the acting in conjunction of neopelex, chelating agent and deionized water, make the present invention cut the ability that liquid has good cleaning decontamination.
(3) neopelex has very high surface-active among the present invention; Its critical micelle concentration (cmc) has only 0.0012 mol/L; Under extremely low concentration, can significantly reduce the surface tension of cutting liquid, effectively strengthen the wetability and the lubricated permeability of cutting liquid.Adopt the antifoaming agent of dimethicone in addition, in effective froth breaking, also can play lubricated effect to a certain extent, and reduce surface tension, strengthen wetting and permeability as cutting liquid.So under neopelex and dimethicone acting in conjunction, can significantly improve the wetting and lubricated permeance property of cutting liquid, this is to make the present invention cut the major reason that liquid has lower coefficient of friction.
(4) diethanol amine among the present invention is as the organic base of regulating cutting liquid pH value, and regulating power is strong, and its degree of ionization in solution is similar to highly basic, the chemical action in can effectively reinforcement cutting process, and effectively reduce stress and damage.Research shows; When near pH value during greater than isoelectric point (pH=3.9), the Zeta potential on SiC surface raises with the rising of pH value, and the present invention cuts the pH value of liquid under the effect of diethanol amine; The pH value reaches 11 ~ 12; Can improve the Zeta potential of grain greatly, thereby the electrostatic repulsion between the abrasive particle is strengthened, improve dispersed.So diethanol amine when strengthening chemical action, reducing surface damage and stress, can also improve the dispersion suspension property of SiC abrasive particle in the cutting liquid, this is that the present invention cuts the another major reason that liquid has the higher suspension rate and forms low roughness, low injured surface.
(5) diethanol amine also can become stable product with complexing of metal ion; Reduce the pollution of metal ion to a certain extent; Be used with chelating agent disodium ethylene diamine tetraacetate among the present invention, be used for complexation of metal ions, can reduce the pollution of metal ion to a great extent.
In sum, the present invention has strengthened the alkalescence of wire cutting liquid, thereby has improved the chemical action in the cutting process, reduces the strong mechanical friction effect of abrasive particle and material, can effectively reduce surface stress and damage, and cutting off machine is played rust inhibition; With the polyethylene glycol is main body, and wellability is good, and the chip removal ability is strong, and carborundum class abrasive material is had the characteristic of higher suspension, high lubricated, high dispersive; Have higher water content and defoaming effect, make the cutting liquid have be with preferably hot; Have suitable viscosity index, make the flowability and the hanging wire performance of cutting liquid obtain better optimized; Under the acting in conjunction of surfactant, antifoaming agent, chelating agent, can under extremely low concentration, significantly reduce the surface tension of cutting liquid, improve its permeability, can effectively remove metal ion simultaneously, be prone to clean.
Description of drawings
Fig. 1 acts on the principle schematic that SiC produces sterically hindered and Zeta electric potential for dispersant polyethylene glycol in the raw material components of the present invention and surfactant neopelex.
Fig. 2 be prepared wire cutting liquid of embodiment 1 ~ 3 and Comparative Examples wire cutting liquid coefficient of friction over time.
The specific embodiment
Introduce effect of the present invention below in conjunction with specific embodiment and experimental data.
Embodiment 1: the wire cutting liquid that disposes 100 g
Taking polyethylene glycol 400 (PEG 400) 60 g under the condition of continuous stirring, slowly add the deionized water of 25 g respectively, the diethanol amine of 8 g, the dimethicone of 2 g, the neopelex of 4 g, the disodium ethylene diamine tetraacetate of 1 g.Be stirred well to whole dissolve the wire cutting liquid of 100 g.
Above-mentioned wire cutting liquid is mixed with the green SiC abrasive material of 800# of 80 g, stir, promptly can be used as the slurry of silicon crystal line cutting through the magnetic stirring apparatus brute force.
Embodiment 2: the wire cutting liquid that disposes 100 g
Taking polyethylene glycol 400 (PEG 400) 65 g under the condition of continuous stirring, slowly add the deionized water of 14 g respectively, the diethanol amine of 10 g, the dimethicone of 4 g, the neopelex of 5 g, the disodium ethylene diamine tetraacetate of 2 g.Be stirred well to whole dissolve the wire cutting liquid of 100 g.
Above-mentioned wire cutting liquid is mixed with the green SiC abrasive material of 800# of 80 g, stir, promptly can be used as the slurry of silicon crystal line cutting through the magnetic stirring apparatus brute force.
Embodiment 3: the wire cutting liquid that disposes 100 g
Taking polyethylene glycol 400 (PEG 400) 70 g under the condition of continuous stirring, slowly add the deionized water of 3 g respectively, the diethanol amine of 12 g, the dimethicone of 6 g, the neopelex of 6 g, the disodium ethylene diamine tetraacetate of 3 g.Be stirred well to whole dissolve the wire cutting liquid of 100 g.
Above-mentioned wire cutting liquid is mixed with the green SiC abrasive material of 800# of 80 g, stir, promptly can be used as the slurry of silicon crystal line cutting through the magnetic stirring apparatus brute force.
Comparative example: certain market cutting liquid 100 g
Use silicon crystal wire cutting liquid 100 g that bought on certain market, with the green SiC abrasive material of the 800# mixing and stirring of itself and 80 g.
The embodiment effect:
In order to investigate the performance of this wire cutting liquid, at first use Accurate pH instrumentation amount pH value of slurry; Secondly, wire cutting liquid is slowly poured in the tool plug graduated cylinder of 100 ml to liquid level and alignd with 100 ml graduation marks, observe the height of clear liquid behind 48 h, by formula suspensibility is calculated in (1), in order to estimate the dispersion suspension performance of cutting liquid:
In the formula,
is suspensibility, and H is tool plug graduated cylinder 100 ml graduation mark place height; H is a clear liquid height behind 48 h, then, and on MMW-1A type abrasion tester; With the friction-wear test of slurry as silicon crystal; (test power: 20 N, the speed of mainshaft: 60 rpm, friction pair: little thrust circle friction pair under experimental condition; Test period: 20 min); Measure its coefficient of friction f, by formula (2) calculate the silicon material material removal rate (material removal rate, MRR):
In the formula;
is average quality before the silicon grinding abrasion;
is wearing and tearing back average quality;
is the density of silicon; T is a test period, and s is the fray area.
At last, with scanning probe microscopy scanning fray surface topography, measure its fray surface roughness Ra, in order to estimate the cutting performance of slurry.
Test result such as table 1 are with shown in Figure 2, and wherein table 1 be the comparison of embodiment 1 ~ 3 and Comparative Examples wire cutting liquid performance, Fig. 2 be embodiment 1 ~ 3 and Comparative Examples wire cutting liquid coefficient of friction over time.
Table 1 embodiment 1 ~ 3 and Comparative Examples wire cutting liquid performance are relatively
Can find out that from table 1 the pH value of three embodiment and suspensibility are obviously greater than comparative example, the fray surface roughness then is significantly less than comparative example.As can beappreciated from fig. 2, the coefficient of friction of three embodiment each time period all less than comparative example.
Hence one can see that, and the present invention has strengthened the alkalescence of wire cutting liquid, thereby can strengthen the chemical action of cutting process, effectively reduces surface damage and stress; The present invention cuts liquid and has high suspensibility, and the SiC micro mist can cut good dispersion suspension in the liquid in the present invention; Wire cutting liquid coefficient of friction of the present invention is less, shows that the lubricated permeability of cutting liquid is better, can effectively reduce friction, reduces stress.Though the present invention is low slightly aspect material removal rate, the surface roughness that obtains is less, and top layer and subsurface stratum damage are little, have better surface quality.
Claims (5)
1. a silicon crystal wire cutting liquid is characterized in that the mass percent of its component and each component is following: dispersant 60 ~ 70 wt%, organic base 8 ~ 12 wt%, surfactant 4 ~ 6wt%, antifoaming agent 2 ~ 6 wt%, chelating agent 1 ~ 3 wt%, deionized water 3 ~ 25 wt%.
2. silicon crystal line according to claim 1 is cut liquid, it is characterized in that said dispersant is a polyethylene glycol; Said organic base is a hydramine alkali; Said surfactant is an anion surfactant; Said antifoaming agent is a silicone oil.
3. silicon crystal wire cutting liquid according to claim 2 is characterized in that said polyethylene glycol is a PEG400, and said hydramine alkali is diethanol amine, and said silicone oil is dimethicone, and said anion surfactant is a neopelex.
4. silicon crystal wire cutting liquid according to claim 1 is characterized in that described chelating agent is a disodium ethylene diamine tetraacetate.
5. silicon crystal wire cutting liquid according to claim 1 is characterized in that the preparation method of said cutting liquid is: get dispersant, under stirring condition, add deionized water; Make it to dissolve each other fully with dispersant; And then the adding organic base, stir, and then add antifoaming agent; Add surfactant and chelating agent at last, stirring gets final product.
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| CN201210267898XA CN102784977A (en) | 2012-07-31 | 2012-07-31 | Silicon crystal line cutting fluid |
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| CN201210267898XA CN102784977A (en) | 2012-07-31 | 2012-07-31 | Silicon crystal line cutting fluid |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105754700A (en) * | 2016-03-23 | 2016-07-13 | 苏州亚思科精密数控有限公司 | Environment-friendly micro-emulsified cooling liquid and preparation method |
| CN112334604A (en) * | 2018-05-25 | 2021-02-05 | 弗劳恩霍夫应用研究促进协会 | Apparatus and method for electrochemical machining of materials |
| CN112658411A (en) * | 2020-12-11 | 2021-04-16 | 东莞市克鲁森润滑油有限公司 | High-mirror-surface spark processing liquid and preparation method thereof |
| CN115572577A (en) * | 2022-01-27 | 2023-01-06 | 淄博理研泰山涂附磨具有限公司 | High-fluidity grinding material and preparation method thereof |
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| CN102344776A (en) * | 2010-08-06 | 2012-02-08 | 安集微电子（上海）有限公司 | Cutting fluid for cutting of scroll saw |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105754700A (en) * | 2016-03-23 | 2016-07-13 | 苏州亚思科精密数控有限公司 | Environment-friendly micro-emulsified cooling liquid and preparation method |
| CN112334604A (en) * | 2018-05-25 | 2021-02-05 | 弗劳恩霍夫应用研究促进协会 | Apparatus and method for electrochemical machining of materials |
| CN112334604B (en) * | 2018-05-25 | 2023-08-25 | 弗劳恩霍夫应用研究促进协会 | Device and method for electrochemical processing of materials |
| CN112658411A (en) * | 2020-12-11 | 2021-04-16 | 东莞市克鲁森润滑油有限公司 | High-mirror-surface spark processing liquid and preparation method thereof |
| CN115572577A (en) * | 2022-01-27 | 2023-01-06 | 淄博理研泰山涂附磨具有限公司 | High-fluidity grinding material and preparation method thereof |
| CN115572577B (en) * | 2022-01-27 | 2024-02-27 | 淄博三共泰山涂附磨具有限公司 | High-fluidity abrasive and preparation method thereof |
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Application publication date: 20121121 |