KR100896071B1 - Reclaiming method of silicon powder - Google Patents

Abstract

The present invention relates to a regeneration method that collects, purifies and regenerates silicon powder from a slurry generated from a back lapping process, which is a semiconductor back process, and more particularly, a slurry generated from a back lapping process. A low-purity silicon powder is collected using a collecting centrifuge, the silicon powder collected from the collecting centrifuge is mixed with a chemical solution to dissolve impurities, and the silicon powder mixed with the chemical solution is used in a centrifuge for tablets. The present invention relates to a method for regenerating silicon powder from a slurry resulting from a back lapping process of obtaining a silicon powder purified by the reclaimed powder and regenerating it into high purity silicon powder.

Regeneration method of the silicon powder from the slurry generated from the back lapping process of the present invention,

The slurry generated from the back lapping process is supplied to a collection centrifuge in which the Paul and the screw are installed horizontally and the Paul motor (M1) and the screw shaft motor (M2) are installed so that the rotation of the paul and the screw is controlled. A collecting step (S100) of collecting the silicon powder from the slurry by a separation method;

A stirring step (S210) of dissolving impurities by mixing the silicon powder collected in the collecting step (S100) with a chemical solution having an acid as a main component; A purification step (S200) of purifying the silicon powder collected from the slurry consisting of a separation step (S220) of supplying the mixture mixed in the stirring step (S210) to a centrifuge for purifier to separate the silicon powder;

A drying step (S300) of drying the silicon powder purified in the purification step (S200) in a vacuum dryer;

Packing step (S400) of packaging the silicon powder dried in the drying step (S300).

Wafer, Backlapping, Slurry, Silicon Powder, Centrifuge, Purifier, Regeneration Method

Description

Recycling method of silicon powder from slurry generated from back lapping process {RECLAIMING METHOD OF SILICON POWDER}

The present invention relates to a regeneration method that collects, purifies and regenerates silicon powder from a slurry generated from a back lapping process, which is a semiconductor back process, and more particularly, a slurry generated from a back lapping process. A low-purity silicon powder is collected using a collecting centrifuge, the silicon powder collected from the collecting centrifuge is mixed with a chemical solution to dissolve impurities, and the silicon powder mixed with the chemical solution is used in a centrifuge for tablets. The present invention relates to a method for regenerating silicon powder from a slurry resulting from a back lapping process of obtaining a silicon powder purified by the reclaimed powder and regenerating it into high purity silicon powder.

In general, the process of processing semiconductor wafers is generally divided into preparatory stage, preprocess, and postprocess.

The previous process refers to wafer fabrication that forms electronic circuits by forming various kinds of films on the surface of the wafer, and repeatedly scrapes a specific part by using a mask that has already been made. It is called.

The post-process is divided into a back lapping process of cutting the back surface of the wafer having electronic circuits on one side to a predetermined thickness, an assembly process of cutting chips on the wafer individually and combining them with a lead frame, and an inspection process.

Normally, semiconductor wafers are manufactured in 3 ", 4", 6, "and 8" depending on the size, and the thickness is about 600 ~ 800㎛ for the first time, and about 200㎛ after wafer processing. Shave off.

The slurry generated in the back lapping process of the back-end process, which is a semiconductor manufacturing process, includes silicon powder, and the size of the silicon powder contained in the slurry has a size of 0.02-5 μm, an average of 2 Have a size of μm.

The content of the silicon powder contained in the slurry generated in the back lapping process is about 0.05%, which includes 0.5 kg of silicon powder per 1000 kg, and is currently used in a semiconductor company in Korea. The amount is 2000 tons per day. The amount of silicon powder contained in the 2000 ton slurry is about 1 ton.

The use of semiconductors is increasing due to the development of industrial technology, and thus the amount of slurry generated during semiconductor processing is increasing.

As described above, the content of the silicon powder contained in the slurry generated in the back lapping process is not only very small but also the size of the silicon powder is fine, so it is very difficult to collect and is usually disposed of through a waste company.

The present invention is a regeneration method for collecting and purifying a slurry generated in a back lapping process, which is usually treated as waste, to regenerate it into high purity silicon powder of about 99.9999% (6N).

In general, when the centrifuge is used to collect the silicon powder contained in the slurry, the centrifuge and its operation method are generally characterized by the size and content of the silicon powder contained in the slurry generated in the back lapping process. Since the silicon powder is not collected, the filter method is used.

A general centrifuge supplies a slurry through a supply pipe, and when the Paul and the screw are rotated, the slurry supplied by the Paul's rotation is subjected to centrifugal force, and the silicon powder contained in the slurry is collected on the inner side of the Paul by the centrifugal force. And the fluid is discharged, and the silicon powder collected on the inner side of the Paul is collected by being discharged to the outlet while a large amount of moisture is dried by Paul's rapid rotation while transferring along the inclined surface of the Paul by a screw.

However, when the size of the silicon powder contained in the slurry generated in the back lapping process is minute, and the centrifuge is used as described above, the silicon powder collected on the inner surface of Paul is first moved when the inclined surface of Paul is moved by the blade of the screw shaft. There is a small amount of scattering, and the more moisture is dried, the amount of scattering increases and eventually the silicon powder is not discharged as an outlet for collecting, and the fine silicon powder of 2 to 3㎛ or less is mostly scattered and discharged to the outside. The silicon powder contained in the slurry generated in the back lapping process was not collected by using a centrifuge because it was mixed with the liquid and then moved outward through the fluid discharge passage. Therefore, the situation is using the waste treatment or the collection method using a filter.

However, the collecting method using the filter has the disadvantage of frequently replacing the filter and the amount of the silicon powder contained in the slurry is small and the collecting amount is low, and the filter component is mixed with the collected silicon powder due to the filter. There is a disadvantage that the purity of the silicon powder falls.

In addition, as a method of purifying low purity silicon powder with high purity, a chemical method is generally used in which the silicon powder is put into a stirrer having a chemical solution and purified by chemical methods.
The chemical solution is used to separate impurities adhering to the silicon powder and is mainly composed of an acid. The acid is usually used for sulfuric acid, hydrogen peroxide, hydrochloric acid, nitric acid, phosphoric acid, and the like, which are used for cleaning and etching wafers of semiconductors. do.

In the conventional chemical method, a device for separating a mixture of a silicon powder and a chemical solution is not provided. Thus, a filter method and a precipitation method have been commonly used.

The separation method by the filter has a disadvantage in that a high purity silicon powder cannot be obtained due to frequent replacement of the filter and foreign matter added to the silicon powder from the filter, and when the separation method is separated by precipitation, a large amount of separation time is required. There was a drawback of not refining the silicone powder.

Therefore, it takes a lot of time to refine the low-purity silicon powder into a high-purity silicon powder, thereby increasing the purification cost.

The present invention invented to solve the above disadvantages,

Back lapping in a short time by providing a method for collecting the silicon powder contained as fine particles in the slurry furnace resulting from the back lapping process with a centrifuge and a method for purifying the silicon powder collected from the centrifuge. The purpose of the present invention is to regenerate the silicon powder by purifying the silicon powder obtained from the slurry into a higher purity silicon powder by providing a regeneration method for collecting, purifying and regenerating the silicon powder from the slurry generated from the back lapping process.

In order to achieve the above object, the method of regenerating silicon powder from the slurry generated from the back lapping process according to the present invention includes the slurry generated from the back lapping process, and the Paul and the screw are horizontally installed, so that the rotation of the paul and the screw shaft is controlled. A collecting step (S100) of collecting silicon powder from the slurry by a centrifugal separation method by supplying the collecting centrifuge having the motor M1 and the screw shaft motor M2 installed therein;

A stirring step (S210) of dissolving impurities by mixing the silicon powder collected in the collecting step (S100) with a chemical solution having an acid as a main component; A purification step (S200) of purifying the silicon powder collected from the slurry consisting of a separation step (S220) of supplying the mixture mixed in the stirring step (S210) to a centrifuge for purifier to separate the silicon powder;

A drying step (S300) of drying the silicon powder purified in the purification step (S200) in a vacuum dryer;

Packing step (S400) of packaging the silicon powder dried in the drying step (S300).

The purification step (S200), drying step (S300) and packaging step (S400) is carried out in a clean room to obtain a high-purity silicon powder.

In the purification step (S200), the separating step (S220) and the separating step (S220) for forming a mixture are repeatedly performed in order of stirring step → separation step → stirring step → separation step to obtain a high purity silicon powder. Usually repeat two to six times.

In the collecting step using the collecting centrifuge (S100), the silicon powder is separated from the slurry from the slurry and the silicon powder is separated from the slurry while Paul stops the screw so that the silicon powder is collected on the inner surface of the Paul. The fluid is rotated at a high speed so as to be discharged to the fluid outlet and collects the silicon powder on the inner surface of the Paul supplying the slurry (S110), and the slurry to discharge the silicon powder collected on the inner surface of the Paul in the step (S110). Stop supplying, Paul decelerates, but decelerates and rotates so that the silicon powder collected on the inner side of the Paul is maintained, and rotates the screw shaft that is stopped to discharge the silicon powder collected on the inner side of the Paul (S120). The collection centrifuge is driven.

The collection centrifuge, using a horizontally installed Paul, and a centrifuge with a screw shaft installed horizontally inside the paul, control the driving and rotation of the screw and the screw shaft to collect the silicon powder of the fine particles, respectively Paul motor (M1) and screw shaft motor (M2) is installed so that.

Separation step (S220) using the centrifuge for the refiner, supplies the mixture to the inside of the Paul, by rotating the Paul at high speed to separate the silicon powder (S) and the chemical solution from the mixture to collect the silicon powder (S) inside the Paul. Collecting step (S221); A chemical solution discharging step (S222) of stopping the supply of the mixture after the collecting step (S221), reducing the rotational speed of the Paul, and discharging the chemical solution remaining in the Paul using a spatula blade; After the chemical solution discharging step (S222) is divided into a collection step (S223) to collect the silicon powder collected inside the Paul by moving the spatula, the centrifuge for the purifier is driven.

The collection centrifuge, the cylindrical housing is installed horizontally, the drain formed in the lower side; A cylindrical-shaped Paul installed to collect silicon powder on an inner side of the housing by a hole formed at one side thereof installed to rotate with the power of a motor inwardly of the housing; A supply pipe installed to supply a mixture of silicon powder to the inside of the paul; An outlet for discharging the silicon powder collected on the inner surface of the paul to the outside; Consists of a spatula blade for supplying the silicon powder collected on the inner surface of the Paul to the outlet, the spatula blade is installed to move outward from the center of rotation of the Paul by a moving device.

The silicon powder contained in the form of fine particles in a small amount in the slurry generated in the back lapping process by the method of regenerating the silicon powder from the slurry generated from the back lapping process of the present invention made as described above can be regenerated with high purity. There is a characteristic.

That is, collecting the silicon powder on the inner surface of the Paul (S110) and collecting the centrifugal separator centrifugally installed horizontally with the Paul and the screw shaft capable of controlling the driving and rotation (S110) and discharging the silicon powder collected on the inner surface of the Paul ( S120) is characterized in that it can collect the silicon powder contained in the form of fine particles in a small amount in the slurry generated in the back lapping process,

The mixture made by mixing the collected low-purity silicon powder with the chemical solution is characterized by being able to separate the purified silicon powder and fluid in a short time using the centrifuge for the purifier provided above.

Therefore, by refining the low purity silicon powder into high purity silicon powder in a short time, there is an effect that can save the regeneration time and the cost of the silicon powder.

Hereinafter, described in detail with reference to the drawings showing an embodiment of the present invention,

1 is a step diagram showing a method of regenerating silicon powder from the slurry generated from the back lapping process of the present invention, Figure 2 is a schematic diagram showing a method of regenerating silicon powder from the slurry generated from the back lapping process of the present invention, the present invention silicon Powder recycling method is to collect the silicon powder from the slurry (10) generated in the back lapping process to the collection centrifuge (S100) (S100), and the low-purity silicon powder collected in the collecting step (S100) Purifying the silicon powder to be purified to high purity by using a centrifuge 300 for the refiner (S200), the drying step (S300) for drying the purified silicon powder in the purification step (S200), and the dried silicon Packaging step is made of packing powder (S400).

The step of collecting the silicon powder from the slurry generated in the back lapping process (S100) is a step of collecting silicon powder on the inner surface of the collecting centrifuge 100 (S110), and in the step (S110) in Paul Discharging the silicon powder collected on the side (S120).

In more detail, in the step of collecting the silicon powder from the slurry (S100), in the state in which the screw shaft is stopped so that the silicon powder is collected on the inner surface of the Paul, the silicon powder and the silicon powder separated from the slurry are separated from the fluid. Collecting the silicon powder on the inner surface of the Paul and collecting the silicon powder on the inner surface of the Paul for supplying the slurry and rotating the fluid at high speed so as to be discharged to the fluid outlet (S110), and the silicon collected on the inner surface of the Paul in the step (S110). The slurry stops the supply to discharge the powder, Paul decelerates, but decelerates and rotates to maintain the silicon powder collected on the inner side of the Paul, and the screw is stopped to rotate to discharge the silicon powder collected on the inner side of the Paul It is made of (S120).

The collection centrifuge 100 is a cylindrical cylindrical pole 120 is installed horizontally so that both ends are supported by a bearing to the inside of the housing 110 of the cylindrical shape formed horizontally as shown in Figs. The screw shaft 130 installed horizontally so that both ends are supported by a bearing and rotated inside the paul 120 may be installed with a motor for Paul M1 and a motor for screw shaft M2, respectively, so that driving and rotation are respectively controlled. Is done.

In more detail, the collection centrifuge 100 is largely cylindrical and horizontally installed in the housing 110, and both ends of the bearing by receiving the power of the motor for Paul (M1) inside the housing 110. Both ends are formed with a horizontal cylindrical cylindrical rod 120 that is supported and rotates, and a screw-shaped blade 131 that rotates by receiving the power of the screw shaft motor M2 inside the paul 120. And horizontally installed cylindrical screw shaft 130, supply pipe 140 for supplying the slurry to the inside of the screw shaft 130, the collecting outlet 150 for discharging the collected silicon powder, and from the slurry The fluid outlet 160 for discharging the fluid from which the silicon powder is separated, the rotation of the paul 120 and the screw shaft 130, and the slurry flow rate Q are controlled by the controller.

The lower side of the housing 110 is provided with a leg 170 is adjustable height to adjust the horizontal of the centrifuge.

The Paul 120 and the screw shaft 130 are addressed to the respective power transmission devices 125 and 135 to be driven by the power of the motor for Paul M1 and the motor for the screw shaft M2, and for each Paul in the controller. The motor M1 and the screw shaft motor M2 are controlled to control the driving and rotation of the paul 120 and the screw shaft 130.

The power transmission devices 125 and 135 generally use a power transmission device using a V-belt, and the power transmission device 125 that transmits power to the Paul 120 has a Paul motor M1 as shown in FIG. 5. The V-belt drive pulley 126 addressed to drive the V-belt driven pulley 127 addressed to the drive pulley 126, and the driven pulley 127 is hollowed out to be spoken with Paul 120. The shaft 128 is rotated to transmit power.

The power transmission device 135 that transmits power to the screw shaft 130 has a V-belt drive pulley 136 addressed to the screw shaft motor M2 as shown in FIG. The belt driven pulley 137 is driven, and the driven pulley 137 rotates the shaft installed inside the connecting bundle 138 to connect the shaft 139 connected with the screw shaft 120 connected with the shaft. Rotate to cut power.

3 to 5, the Paul 120 is formed in a cylindrical shape, formed in a cone shape on one side is formed with an inclined surface 121 inward, the silicon powder is collected toward the end of the inclined surface 121 A plurality of holes 122 are formed in the circumferential direction to discharge, and a plurality of holes 123 are formed in the circumferential direction so that the fluid can be discharged to the other side.

The screw 130 installed into the inside of the Paul 120 is made of a cylindrical shape is formed with a screw-shaped wing 131 to the outside, the sludge supplied to the supply pipe 140 in the front (left side in the drawing) of the inside Is introduced into the inlet chamber 132 is formed, a plurality of supply holes 133 are formed to supply the sludge supplied in the circumferential direction of the inlet chamber 132 to the inside of the Paul (120).

The supply pipe 140 for supplying the slurry is formed to supply the sludge to the inlet chamber 132 of the screw 130, the supply valve 141 is installed to adjust the flow rate (Q) of the slurry.

The collection centrifuge 100 made as described above controls the Paul motor M1 and the screw shaft motor M2 during the collection time Δt1 and the discharge time Δt2 set in the control unit. The driving and rotation of the shaft 130 is controlled, and the flow rate Q of the slurry is adjusted by adjusting the supply valve 141 installed in the supply pipe 140.

In this method of operating the collection centrifuge 100, as shown in FIG. 6, the screw shaft 130 is stopped for the collection time Δt1 input to the control unit, and the slurry 120 is rotated at a high speed at 4000 to 7000 rpm. When supplied to the supply pipe 140, the supplied slurry is supplied to the inside of the Paul 120 through the supply hole 133 formed in the inlet chamber 132 formed in the screw 130, the inside of the Paul 120 The slurry supplied to the silicon powder and the fluid is separated by the high-speed rotation of the Paul (120), the silicon powder is collected on the inner surface of the Paul (120), the remaining fluid from the silicon powder is separated from the slurry is formed in the Paul (120) The fluid is discharged to the fluid outlet 160 through the hole 123.

When the collection time Δt1 input to the control unit elapses, the control unit drives the screw shaft motor M2 to discharge the silicon powder collected on the inner surface of the Paul 120 during the input discharge time Δt2. Rotate 130. At this time, by stopping the supply valve 141 installed in the supply pipe 140 to stop the supply of slurry, the pole 120 is reduced to 1500 ~ 2500rpm to rotate at a low speed.

As shown in FIG. 5, the silicon powder collected on the inner surface of the Paul 120 by the rotation of the screw shaft 130 moves toward the inclined surface 121 of the Paul 120 to form a hole formed at the end of the inclined surface 121. 122 is discharged to the collecting outlet 150 through.

The purification step (S200) is a stirring step (S210) of dissolving impurities in the silicon powder by mixing a low-purity silicon powder collected in the collecting step (S100) with a chemical solution in a stirrer as shown in Figure 1, and the stirring It consists of a separation step (S220) for separating the silicon powder using a centrifuge (300) for purifier from the mixture mixed in step (S210),

The separating step (S220) is a step of collecting the silicon powder in the Paul (S221), the discharge step of discharging the remaining chemical solution in the Paul (S222), and the collection step of collecting the purified silicon powder in the Paul (S223).

The stirring step (S210) and separation step (S220) is repeated as shown in FIG. Usually repeat 1 to 6 times.

The stirring step (S210) is a step of stirring the low-purity silicon powder collected in the collecting step (S100) into a stirrer with a chemical solution to dissolve the impurities mixed in the silicon powder into the chemical solution.

The separation step (S220) is a step of separating the silicon powder from the mixture of the silicon powder in which impurities are dissolved in a chemical reaction with the chemical solution in the stirring step (S210) by the centrifuge 300 for the purifier, the centrifuge for the purifier 300, the collection step (S221) for supplying the mixture to the inside of the Paul, by rotating the Paul at high speed to separate the silicon powder (S) and the chemical solution from the mixture to collect the silicon powder (S) inside the Paul; A chemical solution discharging step (S222) of stopping the supply of the mixture after the collecting step (S221), reducing the rotational speed of the Paul, and discharging the chemical solution remaining in the Paul using a spatula blade; After the chemical solution discharging step (S222) is operated in the collecting step (S223) to collect the silicon powder collected inside the Paul by moving the spatula.

The centrifuge 300 for the refiner is large as shown in Figs. 7 to 10, the housing 320 of the cylindrical shape horizontally installed on the base 310, the rotatable inside the housing 320 Paul 330 having a cylindrical shape and horizontally installed, a motor 340 addressed to a power transmission device for rotating the Paul 330, and a discharge pipe 50 through which silicon powder separated from the Paul 330 is discharged. ), A spatula blade 60 for discharging the silicon powder S separated and collected on the inner surface of the Paul 330, and a mixture of the silicon powder and the chemical solution mixed into the Paul 330. It consists of a supply pipe 70 to.

The base 310 has an upper base 311 formed of a rectangular plate having a thickness as shown in FIGS. 7 and 8, a lower base 312 formed to correspond to the upper base 311, and the upper base ( 311 and the lower base 312 is composed of a plurality of shock absorbing member 313 is installed, the shock absorbing member 313 is a rubber that is usually used to absorb the shock.

The housing 320 is formed in a cylindrical shape as shown in FIGS. 7 to 10 and is installed horizontally on the upper portion of the base 310. A drain 321 is formed at a lower portion thereof to form silicon powder from the mixture in the Paul 330. The remaining fluid from which S is separated is discharged.

One side of the housing 320 is provided with a rotating shaft housing 344, which is installed with a rotating shaft 343, which is addressed to the posture Paul 330, and a cover 322 is formed on the other side.

The Paul 330 is formed in a cylindrical shape as shown in FIG. 9 and installed to rotate horizontally inside the housing 320, and one side is supported to rotate on a rotating shaft 343 installed in the rotating shaft housing 344. Is rotated by the rotation of the rotary shaft 343, the other side is formed with a hole 331 as shown in Figure 9 to 12 except for the fluid excluding the silicon powder (S) of the mixture supplied to the inside of the Paul 330 It is discharged outward through the drain 321 of the housing 320.

The size of the hole 331 formed on one side of the Paul 330 is smaller than the inner diameter of the Paul 320 as shown in Figs. 9 to 12 to form a silicon powder (S) separated and collected on the inner surface of the Paul (330) Is prevented from being discharged through the hole 331.

The motor 340 is installed on one side of the base 310 to rotate the Paul 330 by a power transmission device. The power transmission device includes a driving belt pulley 341, a driven belt pulley 341 and a belt pulley 342 which are extended to the belt as the motor 340 as shown in FIG. 7, and the driven belt pulley. 342 and a rotating shaft 343 that is spoken.

The motor 340 is electrically addressed to the controller to control the driving and rotation of the paul 330 by the controller.

The discharge pipe 350 penetrates through the cover 322 of the housing 320 as shown in FIG. 9 and is installed inside the Paul 320 through the hole 321 of the Paul 320. Separately collected silicon powder (S) to discharge the tube to the outside.

9 through 12, the inlet 351 is formed in the inner side of the paul 320, and the silicon powder S supplied by the spatula blade 360 is set as the inlet 351. Guiding guide plate 352 is formed.

As shown in FIG. 11, the discharge pipe 350 includes a screw shaft 354 having a screw wing formed inside the discharge pipe 350 so as to easily discharge the silicon powder S introduced into the inlet 351 to the outside, and the screw shaft. A screw shaft motor 355 capable of rotating 354 may be further installed, and a discharge port 353 is formed at one side of the discharge pipe 350.

The screw shaft motor 355 is electrically spoken to the controller so that the controller controls the driving and rotation of the screw shaft 354.

The spatula 360 is installed inside the Paul 330 as shown in FIGS. 7 to 12, and is installed to move outward from the center of rotation of the Paul 330 to be separated and collected on the inner side of the Paul 330. Silicon powder (S) is supplied to the inlet 351 of the discharge pipe (350).

The spatula blade 350 is moved outwardly from the inner side (the center of rotation of Paul) of the paul 320 by a moving device, and the moving device for moving the spatula blade 360 is as shown in FIGS. 7 to 10. The spatula blade 363 of the spatula blade 360 is installed to be spaced apart from the center of rotation of the paul 330 and the other side penetrates the cover 322 of the housing 320 and the spatula shaft 363. A cam link 362 fixedly interlocked with the end and a piston 61 pivotally installed on the cam link 362 and pivoted on the cam link 362, the cover of the housing 320 as shown in Figs. On one side of the 322, a stopper 365 for limiting the rotation of the cam link 362 is provided.

In this moving device, the cam link 362 rotates about the spatula shaft 363 by the expansion and contraction of the cylinder 361, and the spatula shaft 363 rotates by the rotation of the cam link 362. The spatula 360 is moved from the inner side of the paul 320 to the outer side as shown in FIGS. 10 to 12.

The pressure sensor 364 is installed at the end of the spatula 360.

The pressure sensor 364 measures the pressure applied to the spatula 360 to distinguish the material guided by the spatula 360.

The cylinder 361 is stretched and controlled by a control unit, so that the control unit controls the movement of the spatula 360, and the control unit is guided from the spatula 360 by a signal transmitted to the pressure sensor 364. Distinguish between phosphorus silicon powder and chemical solution (fluid).

The supply pipe 370 is installed through the cover 322 of the housing 320 to the hole 321 of the Paul 330 to supply the mixture to the inside of the Paul 330, as shown in FIG.

The supply mixture of the silicon powder and the chemical solution is agitated in the stirrer to the supply pipe 370, the control unit to control the supply of the mixture supplied to the supply pipe 370, the normal supply of the supply pipe 370 A valve is installed at the inlet to control the mixture supplied to the supply pipe 370.

The housing 320 and the paul 330 and the discharge pipe 350, the spatula 360, which is the configuration, are treated with Teflon coating so that foreign substances are not included in the silicon powder to be purified.

The drying step (S300) is preferably a step of drying the purified silicon powder with high purity in a vacuum dryer.

The packaging step (S400) is a step of packaging the dried silicon powder.

The purification step 200, the drying step (S300) and the packaging step (S400) are carried out in a clean room state to obtain a high-purity silicon powder.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Figure 1 is a step showing a method for regenerating the silicon powder from the slurry generated from the back lapping process of the present invention.

Figure 2 is a schematic diagram showing a method for regenerating silicon powder from the slurry resulting from the present invention back lapping process.

Figure 3 is a front sectional view of a centrifuge showing a preferred embodiment of the collection centrifuge used in the present invention.

Figure 4 is a partial detailed cross-sectional view of the collection centrifuge used in the present invention.

Figure 5 is a partial detailed cross-sectional view of the collection centrifuge used in the present invention.

Figure 6 is a graph showing the operating step of the present inventors centrifuge.

7 is a plan view of a centrifuge for a purifier used in the present invention.

8 is a side view of a centrifuge for a purifier used in the present invention.

Figure 9 is a front sectional view of a centrifuge for a purifier used in the present invention.

Figure 10 is a side cross-sectional view of a centrifuge for a purifier used in the present invention.

Figure 11 is a partial detailed cross-sectional view of a centrifuge for a purifier according to another embodiment of the present invention.

12 is an operating state diagram of a centrifuge for a purifier showing another embodiment of the present invention.

[Explanation of symbols on the main parts of the drawings]

S100: collection step S200: purification step

S300: drying step S400: packing step

Δt1: collection time Δt2: discharge time

10: slurry

100: collection centrifuge

110: housing 120: Paul

121: slope 122, 123: hole

130: screw shaft 31: wing

133: supply hole 40: supply pipe

M1: Motor for Paul M2: Motor for Screw Shaft

300: centrifuge for purification

310: base 320: housing

321: Drain 330: Paul

331: hole 340: motor

341, 342: belt pulley 343: power transmission shaft

350: discharge pipe 351: inlet

352: guide plate 353: outlet

354: screw shaft 355: motor for screw shaft

360: spatula 361: cylinder

362: cam link 363: spatula shaft

364: pressure sensor 365: stopper

370: supply pipe

Claims (5)

The slurry generated from the back lapping process is installed in the collection centrifuge 100 in which the Paul and the screw are installed horizontally, and the Paul motor M1 and the screw shaft motor M2 are installed so that the rotation of the paul and the screw are controlled. A collecting step (S100) of supplying and collecting the silicon powder from the slurry by centrifugation; A stirring step (S210) of dissolving impurities by mixing the silicon powder collected in the collecting step (S100) with a chemical solution having an acid as a main component; Supplying the mixture mixed in the stirring step (S210) to the centrifuge 300 for the purifier consists of a purification step (S200) for purifying the silicon powder collected from the slurry consisting of a separation step (S220) for separating the silicon powder. A method for regenerating silicon powder from a slurry resulting from a back lapping process. The method of claim 1, A drying step (S300) of drying the silicon powder purified in the purification step (S200) in a vacuum dryer; Recycling method of the silicon powder from the slurry resulting from the back lapping process, characterized in that it further comprises a packaging step (S400) for packaging the dried silicon powder in the drying step (S300). The method of claim 1, Separation step (S220) of separating from the stirring step (S210) to form a mixture in the purification step (S200) is a method of regenerating the silicon powder from the slurry, characterized in that repeated in the stirring step → separation step → stirring step → separation step . The method of claim 1, The collection step (S100) using the collection centrifuge 100, With the screw stopped to collect the silicon powder on the inner side of the Paul, the silicon powder and the fluid were separated from the slurry by Paul. The separated silicon powder was collected on the inner side of the Paul, and the fluid was rotated at high speed to discharge the fluid to the fluid outlet. Collecting the silicon powder on the inner surface of the Paul to supply (S110), In step (S110), the slurry stops the supply so as to discharge the silicon powder collected on the inner surface of Paul, Paul decelerates, but decelerates and rotates to maintain the silicon powder collected on the inner surface of Paul, and the stationary screw is rotated. The method of regenerating the silicon powder from the slurry generated from the back lapping process characterized in that the drive is divided into the step (S120) to discharge the silicon powder collected on the inner surface. The method of claim 1, Separation step (S220) using the centrifuge 300 for the purifier, Supplying the mixture to the inside of the Paul, and collecting the silicon powder (S) inside the Paul by separating the silicon powder (S) and the chemical solution by rotating the Paul at high speed (S221); A chemical solution discharging step (S222) of stopping the supply of the mixture after the collecting step (S221), reducing the rotational speed of the Paul, and discharging the chemical solution remaining in the Paul using a spatula blade; After the chemical solution discharging step (S222), the silicon powder collected in the inside of the Paul is collected by moving the spatula (S223) to recover the silicon powder from the slurry generated from the back-lapping process, characterized in that consisting of.

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