CN102285010B

CN102285010B - Solar-grade silicon chip cut by using diamond wires and cutting method

Info

Publication number: CN102285010B
Application number: CN201110258624XA
Authority: CN
Inventors: 于景; 俞建业; 曾斌; 叶平; 欧阳思周; 汤玮; 胡凯
Original assignee: Energy Technology Co Ltd Jiangxi Jinkui
Current assignee: Energy Technology Co Ltd Jiangxi Jinkui
Priority date: 2011-08-08
Filing date: 2011-09-04
Publication date: 2012-10-03
Anticipated expiration: 2031-09-04
Also published as: CN102285010A

Abstract

The invention discloses a solar-grade silicon chip cut by using diamond wires and a cutting method. The silicon chip cutting technology includes the monocrystal round silicon rod technology and the technology for cutting monocrystal square silicon rods by using diamond wires, wherein the monocrystal round silicon rod technology comprises the following steps: qualified round silicon rods are extracted and barreled by an extracting machine, and a mirror surface effect us achieved after flat grinding and polishing; and the technology for cutting monocrystal square silicon rods by using diamond wires comprises the steps: the surface of the silicon rods undergoing flat grinding and polishing is cleaned, then the silicon rods are bonded on resin rods, the resin rods are fixed on an adhesive board, the silicon rods and the adhesive board are arranged on a diamond wire cutting machine to be cut, and the solar-grade silicon chips are formed by the diamond wire cutting machine. As for the solar-grade silicon chip cut by using diamond wires, the processing technology is advanced and simple, the control precision is high, the silicon powder can be recycled, the manufacturing cost of the silicon sheets are reduced greatly, the phenomenon of breaking of wires are reduced, the production efficiency and the surface quality of the chips are improved, and the qualification rate is increased.

Description

A kind of solar level silicon wafer thin slice and cutting method thereof of using the diamond wire cutting

Technical field

The present invention relates to a kind of solar level silicon wafer thin slice and cutting method thereof of using the diamond wire cutting.

Background technology

Solar level battery silicon wafer is that the silicon single crystal rod cutting is formed at present.And silicon materials shortage in the market, price is higher.In order to reduce production costs, a lot of enterprises are all in the continuous effort of sheet.The silicon suitable for solar purposes sheet thickness of domestic at present, international most of enterprise production is at 200 ± 20 um, and the direction of main flow sheet is that thickness is the silicon chip of 180 ± 20 um.Application number 200810019894.3 has been announced a kind of ultra-thin solar silicon slice and cutting technique thereof; Silicon wafer thickness is between the 165-195um; Angularity is less than 75um; Must use the mortar that stirs by suspension and corundum during cutting; Change simultaneously tradition uses four jiaos of emery wheel barreling as the operation of fillet for adopt silicon crystal bar evolution machine through twice evolution, chamfering with the silicon wafer pole directly cut into the cross section be square, four jiaos be identical 45 to spend the anistree square cylinder of chamferings, and then cut into ultra-thin solar silicon slice.

There is following shortcoming in this ultra-thin solar level silicon wafer:

(1) still there is the damage layer in silicon rod surface after evolution and chamfering, and the surface does not reach mirror effect, in cutting process, possibly cause broken string, increases fragment rate.

The mortar that must use suspension and corundum to stir when (2) cutting, mortar are difficult to recycle, and cause serious environmental to pollute.

(3) this free type mortar cutting is difficult to solve the problems that there are a large amount of damage layers in silicon chip surface, and total thickness variations (TTV), angularity (WARP), flexibility (BOM) index all can be bigger than normal, limited sheet.

Summary of the invention

To the problem that ultra-thin solar silicon slice in the prior art exists, the technical problem that the present invention will solve is through using the diamond wire cutting that a kind of low cost of manufacture, the excellent solar level silicon wafer thin slice of performance are provided.

The technical scheme that the present invention provides a kind of silicon wafer thin slice that uses the diamond wire cutting to produce to be taked is: said silicon wafer sheet thickness 160 ± 15um, and silicon chip total thickness variations (TTV) is less than 10um, and flexibility (BOW) is less than 40um.

The present invention also provides a kind of use diamond wire cutting solar level silicon wafer thin slice cutting technique; Said silicon wafer thin slice cutting process method comprises circular silicon rod technology of monocrystalline and the square silicon rod diamond wire of monocrystalline slice process; The circular silicon rod technology of said monocrystalline is that the circular silicon rod that is up to the standards is carried out the evolution barreling with the evolution machine; Then obtain to meet the square silicon rod of diamond wire cutting technique through plain grinding polishing back; Square silicon rod surface reaches mirror effect, and roughness is less than 0.2um, and the silicon rod depth of parallelism is less than 0.02um; The square silicon rod diamond wire of said monocrystalline slice process is bonded on the resin streak after being the silicon rod process cleaning surfaces with the plain grinding polishing, selects the fat bar because of reaching on the sizing plate; Compress 0.5-3 hour with the 5-10kg compression weight; Static placement is after 6 hours, silicon rod is installed on the diamond wire cutting machine together with the sizing plate cuts into slices, and the diamond wire of 138-150um is used in section; The diamond wire Trace speed is 1000-1400mm/min during section; Workbench decline 0.3-0.8mm/min, diamond wire cutting machine guided wheel slot use the special-purpose cutting of diamond wire liquid apart from 320-340um during cutting.

The special-purpose cutting of said diamond wire liquid is stirred through the stirring at low speed cylinder by the antifoaming agent of the emulsifying agent of the antirust agent of 19～59% polyethylene glycol, 40.5～80.5% pure water, 0.05～0.2%wt, 0.05～0.2%wt and 0.3～0.5%wt and mixed in 2 hours.Close 1.01 ~ the 1.08g/cm of said diamond wire special-purpose cutting liquid ³, viscosity 10 ~ 20 mm ²/ s, coolant rate 300-350 L/min, coolant temperature is in 20-30 ℃ of scope.

Table 1 is for adopting silicon wafer sheet thickness, thickness deviation and the geometric parameter of cutting method processing of the present invention

After adopting technique scheme, make the silicon rod surface form minute surface owing to adopt polisher lapper to carry out plane polishing, adopt the diamond wire cutting technique, cut into solar level silicon wafer thin slice, its advantage is:

(1) solar level silicon wafer thin slice is all formed by the cutting of diamond wire slicer, processing technology elder generation and then simple, and control accuracy is high, and silica flour can be recycled, and greatly reduces the manufacturing cost of silicon chip.

(2) solar level silicon wafer thin slice is in manufacture process; Circular silicon rod is through the laggard parallel planes grinding and polishing of evolution barreling; Make the silicon rod surface reach mirror effect, reduced the broken string phenomenon in the cutting process, improved production efficiency; Sheet surface is bright and clean, smooth, indefectible, has improved product qualified rate.

(3) because the diamond wire cutting technique of adopt optimizing makes the thickness of silicon wafer drop to 160um from 200um, and the flexibility that guarantees silicon wafer is less than 40um, and the silicon wafer quantum of output of per kilogram silicon wafer pole increases, and economic benefit is greatly improved.

The specific embodiment

Present embodiment is that 125 * 125mm solar level silicon wafer thin slice does, silicon wafer thickness 160+/-15um,

A kind of use diamond wire cutting solar level silicon wafer thin slice cutting technique of the present invention; Said silicon wafer thin slice cutting technique comprises: circular silicon rod technology of monocrystalline and the square silicon rod diamond wire of monocrystalline slice process; The circular silicon rod technology of said monocrystalline is that the circular silicon rod that is up to the standards is carried out the evolution barreling with the evolution machine; Then through obtaining to meet the square silicon rod of diamond wire cutting technique behind the gyro-finishing of plane; Square silicon rod surface reaches mirror effect, and roughness is less than 0.2um, and the silicon rod depth of parallelism is less than 0.02um; The square silicon rod diamond wire of said monocrystalline slice process is with behind the process of the silicon rod behind the evolution gyro-finishing cleaning surfaces, is bonded on the resin streak, compresses 1-2 hour with the 5-10kg compression weight; Take off counterweight, static placement 6 hours then is installed on the diamond wire cutting machine and cuts into slices; The diamond wire of 150um is used in section; The diamond wire Trace speed is 1200 mm/min during section, and the workbench decrease speed is at 0.65 mm/min, and diamond wire cutting machine guided wheel slot is apart from 320um; Cooling fluid adopts the special-purpose cutting of diamond wire liquid during section, the special-purpose cutting of said diamond wire liquid density 1.01 ~ 1.08g/cm ³, viscosity 10 ~ 20 mm ²/ s, coolant rate 320 L/min, coolant temperature is in 20-30 ℃ of scope.

Silicon wafer sheet thickness, thickness deviation and geometric parameter by above-mentioned cutting method processing

Because the thickness of present embodiment is 160 ± 15um, thinner than existing regular solar level silicon wafer 200um ± 20um, can have more 10 through calculating per kilogram silicon material, per tonly have more 10000, calculate with 12 yuan/sheet, can increase income 120,000 yuan.

Claims

1. cutting method of using the solar level silicon wafer thin slice of diamond wire cutting; It is characterized in that: said silicon wafer thin slice cutting process method comprises circular silicon rod technology of monocrystalline and the square silicon rod diamond wire of monocrystalline slice process; The circular silicon rod technology of said monocrystalline is that the circular silicon rod that is up to the standards is carried out the evolution barreling with the evolution machine; Then obtain to meet the square silicon rod of diamond wire cutting technique through plain grinding polishing back; Square silicon rod surface reaches mirror effect, and roughness is less than 0.2um, and the silicon rod depth of parallelism is less than 0.02um; After the square silicon rod diamond wire of said monocrystalline slice process is the silicon rod process cleaning surfaces with the plain grinding polishing; Be bonded on the resin streak; Compress 0.5-3 hour with the 5-10kg compression weight; Static placement is after 6 hours, silicon rod is installed on the diamond wire cutting machine cuts into slices, and the diamond wire of 138-150um is used in section; The diamond wire Trace speed is 1000-1400mm/min during section; Workbench decline 0.3-0.8mm/min, diamond wire cutting machine guided wheel slot use the special-purpose cutting of diamond wire liquid apart from 320-340um during cutting; The special-purpose cutting of said diamond wire liquid is stirred through the stirring at low speed cylinder by the antifoaming agent of the emulsifying agent of the antirust agent of the pure water of the polyethylene glycol of 19～59%wt, 40.5～80.5%wt, 0.05～0.2%wt, 0.05～0.2%wt and 0.3～0.5%wt and mixed the special-purpose cutting of said diamond wire liquid density 1.01 ~ 1.08g/cm in 2 hours ³, viscosity 10 ~ 20 mm ²/ s.