KR100839829B1 - Ingot production apparatus and method for solar cell using waste silicon - Google Patents

Abstract

According to the present invention, after removing impurities from waste silicon, a single crystal ingot for solar cells may be grown to produce a single crystal substrate for solar cells, or a single crystal / polycrystalline substrate for solar cells may be manufactured by growing a polycrystalline ingot for solar cells by a polycrystalline casting method. The present invention relates to a method and apparatus for manufacturing a solar cell ingot using waste silicon, which comprises: (1) a primary crushing step of first crushing silicon remaining in a crucible using physical means and thermal expansion principles; (2) a separation step of determining whether impurities attached to one side of the silicon can be automatically separated after heating the first crushed silicon; (3) a resistance measurement step of measuring a resistance value of the first crushed silicon using a resistance measurement probe when it is determined that the automatic separation mode is performed through the separation step; (4) a secondary crushing step of crushing the silicon that is usable through the resistance measurement process by using crushing means in the first crushed silicon; (5) a silicon processing step of performing fine etching to separate impurities attached to the second crushed silicon; And (6) an ingot growth step of growing an ingot for a solar cell using silicon in which the impurities are separated.

Waste Silicon, Ingot, Monocrystalline, Polycrystalline, Solar Cell Substrate

Description

Ingot production apparatus and method for solar cell using waste silicon}

1 is a view for explaining the waste silicon generated during the growth of single crystal silicon ingot,

2 is a view for explaining the configuration of a solar cell ingot manufacturing apparatus using waste silicon according to the present invention;

3 is a view for conceptually explaining a method for manufacturing a solar cell ingot using waste silicon according to the present invention;

4 is a process chart for explaining a method for manufacturing a solar cell ingot using waste silicon according to the present invention;

Figure 5 is a graph showing the test results after recycling to the raw material silicon for solar cells (Pot Loss) in accordance with the present invention.

*** Explanation of symbols on main parts of drawing ***

100: primary shredding means

200: heater

300: resistance measurement probe

400: type measurement probe

500: separation means

600: secondary shredding means

700 silicon processing means

800: metal wire roller

900: Silicone Storage

The present invention relates to a solar cell ingot manufacturing method and apparatus using waste silicon.

More specifically, by growing a single crystal ingot and removing impurities from the waste silicon remaining in the crucible, a single crystal ingot for solar cells can be grown to produce a single crystal substrate for solar cells, or a polycrystalline ingot for solar cells can be grown by a polycrystalline casting method. The present invention relates to a solar cell ingot manufacturing method and apparatus using waste silicon for manufacturing a single crystal / polycrystalline substrate for a solar cell.

In general, a semiconductor silicon wafer fabrication process involves extracting high-purity silicon in an ingot state through silicon single crystal growth in a grower, polishing it to a specification, and processing ingot blocks. After the process, the wafer is cut and the surface of the substrate is polished using wire saws.

As described above, the waste silicon generated during the growth of the single crystal silicon is the top (1), the bottom (Tail, 2) of the ingot as shown in FIG. 1, the slug sample (3) cut for quality evaluation of the ingot. And it can be divided into silicon (Pot Loss = Scrap, 4) remaining in the crucible (5) used for single crystal growth.

At this time, the upper and lower portions (1, 2) of the ingot are classified according to the type (P-Type, N-Type) and the characteristics (Res, Oi, Carbon, Metal etc), and some low-level semiconductors through the purification process And the fact that it is reproduced and used as an ingot for Cathode is widely known.

On the other hand, solar cell ingots have grown into monocrystalline and polycrystalline ingots using silicon or semiconductor grade silicon, which is lower than semiconductor grade in consideration of quantity and price competitiveness, and thus silicon substrate price, which is the raw material cost that determines solar cell price. If this increases, the price of the solar cell increases, there is a problem that the diffusion of the solar cell is delayed, the industrial economics for the solar cell is reduced.

In addition, in the conventional solar cell recycling technology, single crystal silicon is grown, and then processed into a square rectangle using the top and the tail of the ingot as the scrap (waste silicon) part of the silicon ingot, and the processed forward quadrangle A method of manufacturing a solar cell substrate by cutting with a wire saw has already been developed.

However, in the case of silicon remaining in the crucible, since the regeneration treatment method was not introduced because the quality of the substrate and the cell was not satisfied, the regeneration was impossible. It has gone impossible.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to grow a single crystal ingot and remove impurities from the waste silicon remaining in the crucible and grow a single crystal ingot for solar cells to grow a single crystal substrate for solar cells The present invention provides a method and apparatus for manufacturing a solar cell ingot using waste silicon for manufacturing or growing a polycrystalline ingot for a solar cell by a polycrystalline casting method to produce a single crystal / polycrystalline substrate for a solar cell.

One embodiment of the present invention proposed to solve the above technical problem, (1) the primary crushing step of first crushing the silicon remaining in the crucible using a physical means; (2) a separation step of determining whether impurities attached to one side of the silicon can be automatically separated after heating the first crushed silicon; (3) a resistance measurement step of measuring a resistance value of the first crushed silicon using a resistance measurement probe when it is determined as the automatic separation mode through the separation step; (4) a secondary crushing step of crushing the silicon that is usable through the resistance measurement process by using crushing means in the first crushed silicon; (5) a silicon processing step of performing fine etching to separate impurities attached to the second crushed silicon; And (6) an ingot growth step of growing an ingot for a solar cell using silicon in which the impurities are separated.

In addition, another embodiment of the present invention, the crushing means for primarily crushing the silicon remaining in the crucible by applying a physical force to the crucible; A heater heating the first crushed silicon; A resistance measuring probe measuring a resistance of the heated silicon; Separating means for determining whether the silicon is available by receiving the resistance measured through the resistance measuring probe and separating the available silicon; Crushing means for crushing the first crushed silicon in the second case when the usable silicon is found through the resistance measurement process; It is characterized in that it is provided as a silicon processing means to finely etch the secondary crushed silicon to separate the impurities attached to the silicon to grow a solar cell ingot.

Hereinafter, a solar cell ingot manufacturing apparatus using waste silicon will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, a crushing means 100 for primary crushing of silicon remaining in the crucible by applying a physical force to the crucible, and a heater 200 for heating the first crushed silicon; Resistance measurement probe 300 for measuring the resistance value of the heated silicon, type measurement probe 400 for checking the type of primary crushed silicon, and resistance value measured through the resistance measurement probe 300 It is determined by separating the available silicon to receive the input, but the separation means 500 for separating by the type checked by the type measuring probe 400 and, if it is found that the silicon available through the resistance measurement process primary Secondary crushing means 600 for crushing the crushed silicon secondary, and finely etched the secondary crushed silicon to separate impurities attached to one side of the silicon to grow a solar cell ingot Li is made up of silicon processing means 700.

In addition, the separating means 500 is to be transferred to the secondary crushing means 600 only for the silicon having a resistance value of 0.1 to 15Ωcm of the primary crushed silicon.

The secondary crushing means 600 is applied by the thermal shock crushing means or the separating means 500 by applying a thermal shock to the silicon conveyed by the separating means 500 to crush the first crushed silicon secondary One of the ball blasting means (Ball Blasting) for putting the ball into the transferred silicon to crush the first crushed silicon second by the movement of the ball.

The silicon processing means 700 injects an etchant consisting of hydrofluoric acid or a hydrofluoric acid / nitric acid mixture into secondary crushed silicon to etch impurities attached to the waste silicon, and as shown in FIG. A storage box 710 that can be stored, a hydrofluoric acid injection device 720 connected to the storage box 710 to inject 25% hydrofluoric acid into the storage box 710, and etching by the hydrofluoric acid solution. It consists of a steam injection device 730 for injecting steam to clean the waste silicon, and a discharge part 740 provided under the storage box 710 to discharge water formed by hydrofluoric acid and water vapor.

In this case, the hydrofluoric acid injection device 720 is to be injected into the storage box 710 through the passage 723 from the hydrofluoric acid filler 721 and the hydrofluoric acid filler 721 filled with the hydrofluoric acid liquid. It consists of a pump 725. In addition, the submersible injector 730 is a steam filling box 731 filled with water vapor, and the pump 735 to inject water vapor into the storage box 710 through the passage 733 from the steam filling box 731. It is composed.

The separating means 500 injects 25% hydrofluoric acid into the secondary crushed silicon to etch for 3 to 6 hours to achieve fine etching. In this case, the hydrofluoric acid solution may be replaced with a hydrofluoric acid / nitric acid mixture.

The ingot grown from the waste silicon has a characteristic of an oxygen concentration of 1.0xE19 atoms / cm3 or less and a carbon concentration of 5.0xE17 atoms / cm3 or less for producing a solar cell substrate and a cell.

Each waste silicon is transferred to each process region by the metal wire roller 800.

Thus, look at the manufacturing method of the solar cell ingot manufacturing apparatus using the waste silicon as described above are as follows.

2 to 4, when the impact is applied to the outside of the crucible using the primary shredding means 100 made of a physical means such as a hammer, the waste silicon remaining in the crucible is broken by the applied impact. It becomes (S100).

The waste silicon crushed as described above is transferred to the bottom of the heater 200 through the metal wire roller 800. After the waste silicon is heated by the heater 200, the separating means 500 determines whether or not the quartz attached to the waste silicon can be automatically separated, and is capable of automatically separating. If so, transfer to the position to measure the resistance and type of waste silicon. If it is determined that the quartz cannot be automatically separated from the waste silicon, the separation device 500 discharges the worker so as to manually separate the quartz from the waste silicon (S110).

In addition, the separating means 500 measures the resistance of the waste silicon separated as described above using the resistance measuring probe 300 (S120) and determines whether the resistance of the waste silicon is 0.1 to 15 μm cm. As a result of determination, when the resistance value of the waste silicon is included in 0.1 ~ 15Ω㎝, it is separated to perform the next secondary crushing process. If the resistance of waste silicon exceeds 0.1 ~ 15Ωcm, it is regarded as waste and separated and discharged.

At this time, the separation means 500 is a waste silicon is N-type or P-type by using the type measurement probe 400 when the resistance value is contained in 0.1 ~ 15Ω ㎝ as shown above to be recycled silicon Determine and separate (S130).

When the waste silicon separation process is completed as described above, the metal wire roller 800 is moved to the secondary crushing means 600 and crushed more finely (S140).

The secondary crushing means 600 applies thermal shock to the transferred waste silicon, and thermal shock crushing means for crushing the first crushed silicon again to the second or the ball into the transferred silicon as a ball movement The first crushed silicon is secondly crushed by any one of ball blasting (Ball Blasting) means or the like to finely crush the waste silicon before etching.

The finely crushed waste silicon as described above is transferred to the storage box 710 of the silicon processing apparatus 700 and loaded.

When a predetermined amount of waste silicon is loaded into the storage box 710 as described above, the silicon processing apparatus 700 performs a silicon processing process (S150). In more detail with respect to the silicon processing step (S150), 25% of the hydrofluoric acid is filled in the hydrofluoric acid filler 721 by driving the pump 725 of the hydrofluoric acid injection device 720 passage 723 Is moved through to be injected into the storage box (710). The waste silicon loaded in the storage box 710 is immersed in the 25% hydrofluoric acid solution for 3 to 6 hours to perform a fine etching process, and the silicon attached to the waste silicon is separated and recycled by the micro vision process. Will be. At this time, the hydrofluoric acid used in the fine etching process is discharged out of the storage box 710 by the discharge port 740.

The silicon, which has undergone a fine etching process to be recycled as described above, is cleaned by water vapor injected through the steam injection device 730 and then transferred to the silicon storage 900 and stored therein and stored in the silicon storage 900. Is later used to grow solar cell ingots. At this time, the ingot for solar cells has a characteristic of oxygen concentration of 1.0 × E19 atoms / cm 3 or less and carbon concentration of 5.0 × E17 atoms / cm 3 or less.

On the other hand, the waste silicon discharged so that the worker can manually separate the quartz from the waste silicon through the separating means 500, the worker removes the quartz attached to the waste silicon by applying a physical force, the resistance measuring probe Using the 300 and the type measurement probe 400 to measure the resistance value and type of the waste silicon to separate the recyclable waste silicon. Then, the operator cleans the separated waste silicon and manually dry it to store it in a silicon reservoir so that it can be used to grow the solar cell ingot later.

That is, the ingot for the solar cell is grown using the waste silicon treated through the above-described process (S160). At this time, depending on the impurity content of the waste silicon, refined growth may be performed.The grown ingot is cut into squares through block processing, then sliced using a wire saw, and cleaned to make a solar cell wafer. do. The size of the solar cell substrate depends on the growth of the ingot, and the growth of the ingot can grow from 100 mm to 300 mm in width and length.

As described above, the silicon treated to be recycled according to the process can be seen that there is no big problem in using it for solar cells as can be seen in the graph of FIG. 5.

The present invention is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention included in the appended claims.

The present invention having the configuration and operation and the preferred embodiment as described above using the silicon discharged as a waste in the conventional cement factory to produce a solar cell ingot, which is an environmentally friendly energy source, further processing the produced ingot (Slicing) By recycling to a battery substrate, it is possible to reduce environmental pollution as well as to supply the raw materials of solar cells at low cost, thereby increasing the spread of solar cells, which are environmentally friendly energy.

In addition, the present invention is to process the waste silicon by a polycrystalline casting method to produce a polycrystalline substrate for solar cells, as well as to reduce the environmental pollution as described above, and to supply the raw material of solar cells at low cost, solar cells There is an effect to improve the industrial economics for.

Claims (16)

(1) a primary crushing step of first crushing silicon remaining in the crucible using physical means and thermal expansion principles; (2) a separation step of determining whether impurities attached to one side of the silicon can be automatically separated after heating the first crushed silicon; (3) a resistance measurement step of measuring a resistance value of the first crushed silicon using a resistance measurement probe when it is determined as the automatic separation mode through the separation step; (4) a second crushing step of crushing the second crushed silicon first by using a crushing means when it is found to be usable silicon through the resistance measuring process; (5) a silicon processing step of performing fine etching to separate impurities attached to the second crushed silicon; And (6) ingot growth process of growing ingot for solar cell using silicon from which impurities are separated Solar cell ingot manufacturing method using waste silicon, characterized in that consisting of. According to claim 1, wherein the resistance measuring step, And a type checking process of checking a type of primary crushed silicon using a type measuring probe when the automatic separation mode is determined through the separation process. According to claim 1, wherein the resistance measuring step, A method for producing a solar cell ingot using waste silicon, characterized in that the secondary crushing process is performed only on silicon having a resistance of the first crushed silicon of 0.1 to 15Ωcm. The method of claim 1, wherein the secondary crushing step, Method for producing a solar cell ingot using waste silicon, characterized in that the second crushed by applying a thermal shock (Thermal Shock) to the first crushed silicon when it turns out to be usable silicon. The method of claim 1, wherein the secondary crushing step, Method for producing a solar cell ingot using waste silicon, characterized in that the primary crushed silicon when the second crushed silicon by using a ball blasting (Ball Blasting) method. The etching solution of claim 1, wherein Method for producing a solar cell ingot using waste silicon, characterized in that the hydrofluoric acid or hydrofluoric acid / nitric acid mixture. The method of claim 1, wherein the second crushed silicon in the separation process, Method for producing a solar cell ingot using waste silicon, characterized in that the fine etching is performed by etching in 25% hydrofluoric acid for 3 to 6 hours. delete Primary crushing means for primary crushing of the silicon remaining in the crucible by applying a physical force to the crucible; A heater heating the first crushed silicon; A resistance measuring probe measuring a resistance of the heated silicon; Separating means for determining whether the silicon is available by receiving the resistance measured through the resistance measuring probe and separating the available silicon; Secondary shredding means for secondly shredding the first shredded silicon when it is found to be usable by the separating means; Silicon treatment means for processing the second crushed silicon fine etching to separate the impurities attached to the silicon to grow the ingot for solar cells Solar cell ingot manufacturing apparatus using waste silicon, characterized in that provided with. The apparatus of claim 9, wherein the apparatus for producing a solar cell ingot using the waste silicon includes: A solar cell ingot manufacturing apparatus using waste silicon, characterized in that it further comprises a type measuring probe for checking the type of primary crushed silicon. The method of claim 9, wherein the separating means, An apparatus for manufacturing a solar cell ingot using waste silicon, characterized in that the primary crushed silicon is transferred to secondary crushing means only for silicon having a resistance of 0.1 to 15Ωcm. The method of claim 9, wherein the secondary shredding means, Apparatus for manufacturing a solar cell ingot using waste silicon, characterized in that the thermal shock (crushing) the first crushed silicon by applying a thermal shock to the silicon conveyed by the separating means second. The method of claim 9, wherein the secondary shredding means, Ingot manufacturing apparatus for a solar cell using waste silicon, characterized in that the ball blasting (Ball Blasting) means for crushing the first crushed silicon by the movement of the ball by putting the ball into the silicon transferred by the separating means. The method of claim 9, wherein the silicon processing means, An apparatus for producing a solar cell ingot using waste silicon, comprising injecting an etching solution comprising a hydrofluoric acid or a hydrofluoric acid / nitric acid mixture into secondary crushed silicon. The method of claim 14, wherein the separating means, Ingot manufacturing apparatus for solar cells using waste silicon, characterized in that the fine etched for 3 to 6 hours by injecting 25% hydrofluoric acid into the second crushed silicon. delete

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