KR101012518B1 - An apparatus and a method for forming electrode patterns of solar cell using multi-dispensing method - Google Patents

Abstract

PURPOSE: An apparatus and a method for forming an electrode pattern of a solar cell are provided to prevent a silicon wafer from being damaged by forming an electrode pattern with a non-contact method. CONSTITUTION: A first dispensing nozzle(410a) comprises a first nozzle hole for forming a first electrode pattern. A first stage relatively move forward and back based on the first dispensing nozzle. A second dispensing nozzle includes a second nozzle hole for forming a second electrode pattern. A second stage relatively moves forward and backward based on the second dispensing nozzle. A transfer device transfers a silicon wafer from a first stage to a second stage after a first electrode pattern is formed by the first dispensing nozzle.

Description

An Apparatus and A Method for Forming Electrode Patterns of Solar Cell Using Multi-Dispensing Method}

The present invention relates to an electrode pattern forming apparatus and a forming method of a solar cell using a multi-dispensing method. More specifically, the present invention by applying a paste (P) in a non-contact manner using an electrode pattern consisting of bus bars (finger bars) and finger bars (finger bars) formed on the front of the solar cell using a multi-dispensing nozzle By forming, the damage or breakage of the silicon wafer is prevented, the electrode pattern has a regular shape, the formation of the electrode pattern having a fine line width is possible, the thickness of the electrode pattern can be easily adjusted, and the thickness can be easily increased. The present invention relates to an electrode pattern forming apparatus and a method of forming a solar cell using a multi-dispensing method having an effect of implementing an electrode pattern, thereby reducing materials, reducing manufacturing time, increasing solar cell efficiency, and increasing productivity.

Recently, as the prediction of depletion of existing energy sources such as oil and coal is increasing, interest in alternative energy to replace them is increasing. Among them, solar cells are particularly attracting attention because they are rich in energy resources and have no problems with environmental pollution. A solar cell generally refers to a device that converts photons energy into electrical energy using properties of a semiconductor.

1 is a view schematically showing the basic structure of a typical solar cell.

Referring to FIG. 1, a solar cell has a junction structure of a p-type semiconductor 101 and an n-type semiconductor 102, such as a diode, and when light is incident on the solar cell, the solar cell is formed of light and a material constituting the semiconductor of the solar cell. Interactions result in the release of negatively charged electrons and electrons, resulting in positively charged holes. When these electrons and holes move, a current flows, which is called a photovoltaic effect. Of the p-type semiconductor 101 and the n-type semiconductor 102 constituting the solar cell, electrons are attracted toward the n-type semiconductor 102 and holes are directed toward the p-type semiconductor 101, respectively. The electrodes 103 and 104 are bonded to the semiconductor 102. At this time, when the electrodes 103 and 104 are connected by wires, electricity flows to obtain power.

2 is a schematic cross-sectional view of a single crystal silicon solar cell according to the prior art.

2, a silicon solar cell according to the related art includes a first conductive silicon substrate 201, a second conductive conductive layer 202, an antireflection film 205, a front electrode 203, and a rear electrode ( 204). When the second conductive type conductive layer 202, which is a different conductive type layer, is formed on the silicon substrate 201, a p-n junction is formed, thereby forming a p-n structure. As the silicon substrate 201, both a p-type silicon substrate and an n-type silicon substrate may be used. Among them, a p-type silicon substrate having electrons as a minority carrier has a long lifetime and mobility of minority carriers. Most preferably used. The p-type silicon substrate is typically doped with group III elements such as B, Ga, and In, and the n-type conductive layer is formed by doping the p-type silicon substrate with group 5 elements such as P, As, and Sb. A junction can be formed.

Meanwhile, the second conductive conductive layer 202 and the pn junction forming step may be performed in various ways. Typically, a dopant may be formed by placing a silicon substrate in a diffusion furnace and forming a second conductive conductive layer 202. A method of heating a diffusion furnace after injecting a gas containing therein and a method of applying a composition containing a dopant to one surface of a semiconductor substrate and putting it in the diffusion furnace and heating it are used. In the former method, since the second conductivity type conductive layer 202 is formed on the entire surface of the silicon substrate, an edge isolation process of cutting off the side edge portion of the silicon substrate is required. Through this, the electrical connection between the front electrode 203 and the rear electrode 204 can be prevented.

In addition, the anti-reflection film 205 is for lowering the reflectance of sunlight, and is formed on the second conductivity type conductive layer 202 formed on the silicon substrate 201. The anti-reflection film 205 may be formed by a method typically selected from the group consisting of plasma chemical vapor deposition (PECVD), chemical vapor deposition (CVD), and sputtering. A passivation layer (not shown) may be further formed between the anti-reflection film 205 and the second conductivity type conductive layer 202, and the passivation layer may typically include silicon oxide.

In addition, the front electrode 203 includes an electrode pattern including a plurality of finger bars and one or more bus bars electrically connecting the plurality of finger bars. The front electrode 203 is formed on the antireflection film 205 and penetrates the antireflection film 205 and is connected to the second conductivity type conductive layer 202. The finger bar 303a and the bus bar 303b of the front electrode 203 (refer to FIG. 3 below) may be made of a paste including silver (Ag) and glass frit, and the back electrode ( 204 may typically consist of a paste comprising aluminum and glass frit.

The front electrode 203 and the back electrode 204 described above may be formed by, for example, a heat treatment process after applying an electrode forming paste according to a predetermined pattern. Through heat treatment, the front electrode 203 penetrates the anti-reflection film 205 and is connected to the second conductive type conductive layer 202, and the silicon substrate 201 has a back electrode 204 on the silicon substrate 201. The back surface field (BSF) layer 206 is formed from a surface in contact with the surface to a predetermined depth. Since the order of formation of the front electrode 203 and the formation of the back electrode 204 is not limited, it is also possible to form any one first or to apply heat treatment to each paste at the same time.

The silicon solar cell according to the prior art illustrated in FIGS. 1 and 2 is a Korean patent application No. 10-A on April 12, 2007 named “front electrode pattern of a single crystal silicon solar cell and a single crystal silicon solar cell”. It is described in detail in Korean Patent Publication No. 10-2008-0092583, filed 2007-0036077, published October 16, 2008.

3A is a schematic view illustrating a screen printing method for forming an electrode pattern including a plurality of finger bars and at least one bus bar of a silicon solar cell according to the prior art, and FIG. 3B is a screen according to the prior art. A diagram illustrating the steps of the printing method.

Referring to FIG. 3A, in the screen printing method according to the related art, a screen having a silicon wafer W positioned on a table T and a plurality of pattern openings 312 positioned on the silicon wafer W is provided. 310 is used. The screen 310 is positioned on the silicon wafer W spaced apart by the gap G height. Both ends of the screen 310 are fixedly mounted to a pair of frames 314 to maintain a constant tension.

Referring to FIG. 3B, in step (1) of the screen printing method according to the related art, the paste P is provided on the screen 310, and a squeegee 316 slides the paste P in a horizontal direction. Push it out in the (A direction). Thereafter, the paste P is printed onto the silicon wafer W while the squeegee 316 passes through the first pattern opening 312a in step (2). In this case, the squeegee 316 receives the force in the downward direction (B direction) to bring the screen 310 into contact with the silicon wafer (W). Thereafter, in step (3), the paste P is printed onto the silicon wafer W while the squeegee 316 passes through the second pattern opening 312b. Thereafter, in step (4), the paste P is printed onto the silicon wafer W while the squeegee 316 passes through the third pattern opening 312c. Meanwhile, in steps (2) to (4), as the squeegee 316 continues to move in a horizontal square, the first to third pattern openings 312a, 312b, and 312c are sequentially spaced from the silicon wafer W so that the screen ( 310 is maintained in a state where a constant gap G (see FIG. 3A) is maintained on the silicon wafer W. As shown in FIG. As a result, the paste P printed on the silicon wafer W forms the electrode pattern 303 (ie, the plurality of finger bars 303a or one or more bus bars 303b). Thereafter, the paste P remaining on the screen 310 is removed using a scraper 318 shown in FIG. 3A.

As described above, the screen printing method of the related art using the screen 310 and the squeegee 316 has the following problems.

1. The squeegee 316 applies pressure on the silicon wafer W while slidingly moving on the screen 310. In this case, since the squeegee 316 moves, the position of the portion under pressure on the silicon wafer W also changes continuously. In addition, when the squeegee 316 passes over the plurality of pattern openings 312, since the silicon wafer W is momentarily not subjected to pressure, the upper surface of the silicon wafer W may generate pressure variation as a whole. The silicon wafer W has a very thin thickness of about 0.2 mm. Thus, when forming the electrode pattern 303 (i.e., the finger bar 303a or the bus bar 303b) using the screen printing method of the prior art, the silicon wafer W is damaged by the above-described pressure deviation, or Can be broken.

2. After the paste P is printed onto the silicon wafer W, the paste P remaining on the screen 310 must be removed by the scraper 318. Therefore, since the material according to the residual paste P is consumed, the cost increases, and the processing time due to the removal of the residual paste P increases.

3. In addition, when forming the electrode pattern 303, a plurality of finger bars 303a should be formed first, and then one or more bus bars 303b should be formed in a direction crossing the plurality of finger bars 303a. . Thus, the process time for forming the electrode pattern 303 increases.

4. Since the electrode pattern 303 is formed using the screen 310, the electrode pattern formed on the silicon wafer W by the adhesion between the paste P and the portions of the plurality of pattern openings 312 of the screen 310. The shape of 303 is irregular. Referring to FIG. 3C, the shape of both side portions 303s of the electrode pattern 303 formed on the silicon wafer W using the screen printing method of the related art is not only irregular, but also in the width direction of the electrode pattern 303. It can be seen that it has a state spread in (ie, the W1 direction). When the electrode pattern 303 has an irregular shape, the plurality of electrode patterns 303 have different resistance values from each other, and thus the current values flowing through the plurality of electrode patterns 303 are also different. As a result, the resistance values are low. Excessive current flows in the electrode pattern 303 and a short may cause a failure of the solar cell. In addition, when the electrode pattern 303 has a state spread in the width direction, the value of the solar energy absorbed through the anti-reflection film 205 shown in FIG. 2 is reduced. Thus, the efficiency of the solar cell is lowered.

The present invention is to solve at least one or more of the above-described problems of the prior art, using a multi-dispensing method of the electrode pattern consisting of bus bars (finger bars) and bus bars formed on the front surface of the solar cell By applying the paste (P) in a non-contact manner to prevent damage or damage to the silicon wafer, the electrode pattern has a regular shape, it is possible to form an electrode pattern of fine line width, and to control the thickness of the electrode pattern It is easy to increase the thickness and can also implement the electrode pattern on the ultra-sized silicon wafer substrate, so that the electrode of the solar cell using a multi-dispensing method that has the effect of saving material, shortening manufacturing time, increasing efficiency of the solar cell, and increasing productivity It is for providing a pattern forming apparatus and a forming method.

According to a first aspect of the invention, in the electrode pattern forming apparatus of the solar cell using a multi-dispensing method, at least one for forming a first electrode pattern constituting the front electrode of the solar cell on the silicon wafer (W) A first dispensing nozzle having a first nozzle hole; A first stage on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the first dispensing nozzle; A second dispensing nozzle having at least one second nozzle hole for forming a second electrode pattern constituting the front electrode; A second stage on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the second dispensing nozzle; And a transfer device for transferring the silicon wafer W from the first stage to the second stage after the first electrode pattern is formed by the first dispensing nozzle.

According to a second aspect of the present invention, in the electrode pattern forming apparatus of a solar cell using a multi-dispensing method, at least one for forming a first electrode pattern constituting the front electrode of the solar cell on the silicon wafer (W) A first dispensing nozzle having a first nozzle hole; A second dispensing nozzle having at least one second nozzle hole for forming a second electrode pattern constituting the front electrode; And a stage S on which the silicon wafer W is mounted, which is capable of moving forward and backward relative to the first dispensing nozzle and the second dispensing nozzle, and capable of rotational movement. have.

According to a third aspect of the present invention, in the method of forming an electrode pattern of a solar cell using the multi-dispensing method, a) a width M corresponding to the width of the first and second electrode patterns constituting the front electrode of the solar cell; Providing first and second dispensing nozzles each having one or more nozzle holes each having: b) forming a first electrode pattern on the silicon wafer (W) by moving the first stage (S1) on which the silicon wafer (W) is mounted relative to the first dispensing nozzle; c) rotating the silicon wafer W on which the first electrode pattern is formed by 90 °; d) transferring the silicon wafer (W) onto a second stage (S2); And e) forming the second electrode pattern 403b on the silicon wafer W by moving the second stage S2 relative to the second dispensing nozzle.

According to a fourth aspect of the present invention, in the method of forming an electrode pattern of a solar cell using the multi-dispensing method, a) a width M corresponding to the width of the first and second electrode patterns constituting the front electrode of the solar cell; Providing first and second dispensing nozzles each having one or more nozzle holes each having: b) forming the first electrode pattern (403a) on the silicon wafer (W) by moving the stage (S) on which the silicon wafer (W) is mounted relative to the first dispensing nozzle; c) rotating the silicon wafer W on which the first electrode pattern is formed by 90 °; And d) forming the second electrode pattern 403b on the silicon wafer W by moving the stage S relative to the second dispensing nozzle.

Using the electrode pattern forming apparatus and the forming method using the multi-dispensing method of the solar cell of the present invention the following advantages are achieved.

1. Since the multi-dispensing method is a non-contact method, there is no pressure applied to the silicon wafer W when forming the electrode pattern, so there is no pressure deviation occurring on the upper surface of the silicon wafer W. Therefore, damage or breakage of the silicon wafer W is prevented when forming the electrode pattern.

2. Compared with the prior art, the waste of the material (that is, the paste P) is reduced and the cost is reduced. Unlike the prior art, the removal process of the residual paste P is unnecessary.

3. Since the electrode pattern consisting of a plurality of finger bars and one or more bus bars can be simultaneously formed on the silicon wafer W, the processing time is significantly reduced.

4. In the multi-dispensing method, the electrode pattern finally formed in a non-contact manner is uniformly formed. Therefore, the plurality of electrode patterns have substantially the same resistance value, thereby minimizing the possibility of a short and a failure of the solar cell. In addition, since the width direction of the electrode pattern is uniformly formed, the area of the anti-reflection film is increased. Therefore, the electrical conductivity of the solar cell is improved, it is possible to manufacture a highly efficient solar cell.

5. Since the multi-dispensing method is a non-contact method, the number and time of electrode pattern former processes of the solar cell are significantly reduced, thereby increasing productivity.

6. Since the multi-dispensing method is a non-contact method, it is easy to adjust the line width and height of the electrode pattern, and it is possible to form the electrode pattern on the ultra-large silicon wafer (W).

Further advantages of the present invention can be clearly understood from the following description with reference to the accompanying drawings, in which like or similar reference numerals denote like elements.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention.

4A is a schematic cross-sectional view of an electrode pattern forming apparatus of a solar cell using a multi-dispensing method according to a first embodiment of the present invention, and FIG. 4B is a first embodiment of the present invention shown in FIG. 4A. Figure is a side cross-sectional view schematically showing an electrode pattern forming apparatus of a solar cell using a multi-dispensing method according to the example. In FIG. 4B, for convenience of description, the first and second stages S1 and S2, the silicon wafer W, and the first and second dispensing nozzles 410a and 410b are shown in partial perspective. Care must be taken.

4A and 4B, the electrode pattern forming apparatus 400 of the solar cell using the multi-dispensing method according to the first embodiment of the present invention forms a front electrode of the solar cell on the silicon wafer (W). A first dispensing nozzle 410a having one or more first nozzle holes 411a (see FIGS. 4C and 4D) for forming the first electrode pattern 403a; A first stage (S1) on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the first dispensing nozzle (410a); A second dispensing nozzle 410b having at least one second nozzle hole 411b (see FIGS. 4C and 4D) for forming a second electrode pattern 403b constituting the front electrode; A second stage (S2) on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the second dispensing nozzle (410b); And after the first electrode pattern 403a is formed by the first dispensing nozzle 410a, the silicon wafer W is transferred from the first stage S1 to the second stage S2. A transfer device 440. Here, the transfer device 440 may be implemented by, for example, a robot arm or a conveyor. In addition, the first electrode pattern 403a and the second electrode pattern 403b constituting the electrode pattern 403 are formed perpendicular to each other. The first electrode pattern 403a and the second electrode pattern 403b may each be a plurality of finger vias or one or more bus bars. That is, when the first electrode pattern 403a is a plurality of finger bars, the second electrode pattern 403b is at least one bus bar, and when the first electrode pattern 403a is at least one bus bar, the second electrode pattern 403b is A plurality of finger bars.

In the embodiment of FIGS. 4A and 4B described above, the first dispensing nozzle 410a is detachably mounted to the first gantry 416a. The first gantry 416a is mounted on a pair of first linear motion guides 448a to enable forward and backward movements. The pair of first linear motion guides 448a is located on the first table T1. Here, the use of a pair of first linear motion guides 448 is optional. The silicon wafer W is mounted on the first stage S1 capable of moving forward and backward. The first stage S1 is relatively movable with the first dispensing nozzle 410a of the present invention that is movably mounted on the first table T1. In addition, the second dispensing nozzle 410b is detachably mounted to the second gantry 416b. The second gantry 416b is mounted on a pair of second linear motion guides 448b to enable forward and backward movement. The pair of second linear motion guides 448b is located on the second table T2. Here, the use of a pair of second linear motion guides 448b is optional. After the first electrode pattern 403a is formed by the first dispensing nozzle 410a, the silicon wafer W is transferred onto the second stage S2 capable of moving forward and backward by the transfer device 440. The second stage S2 is relatively movable with the second dispensing nozzle 410a of the present invention that is movably mounted on the second table T2.

As shown in FIGS. 4A and 4B, the first stage S1 moves on the first table T1. When the first stage S1 moves along the horizontal direction (A1 direction in FIG. 4B), the first dispensing nozzle 410a is pasted onto the silicon wafer W through the one or more first nozzle holes 411a. P) is discharged. As a result, the first electrode pattern 403a is formed on the silicon wafer W. As shown in FIG. In this case, since the first dispensing nozzle 410a is fixedly mounted on the first table T1, the pair of first linear motion guides 448a need not be used.

Meanwhile, when the first stage S1 is stopped, the first dispensing nozzle 410a mounted on the first gantry 416a may be provided with a pair of first linear motion guides provided on the first table T1. The first electrode pattern 403a is formed on the silicon wafer W mounted on the stationary first stage S1 while moving in the horizontal direction (A2 direction in FIG. 4B) along 448a.

As described above, after the first electrode pattern 403a is formed on the silicon wafer W, the silicon wafer W is transferred to the second stage S2 by the transfer device 440. Since the first electrode pattern 403a and the second electrode pattern 403b should be formed perpendicular to each other, the silicon wafer W should be rotated 90 ° after the first electrode pattern 403a is formed. The 90 ° rotational operation of the silicon wafer W may be performed by the transfer device 440 or the first stage S1. For example, the transfer device 440 may move the silicon wafer W 90 ° while transferring the silicon wafer W having the first electrode pattern 403a from the first stage S1 to the second stage S2. Can be rotated. In this case, the rotational movement of the first stage S1 is unnecessary. Alternatively, after the first electrode pattern 403a is formed on the silicon wafer W, the first stage S1 may rotate the silicon wafer W by 90 °. In this case, the first stage S1 should have a rotation movement function in addition to the forward and backward movement functions.

Thereafter, when the second stage S2 moves along the horizontal direction (the A1 direction in FIG. 4B) on the second table T2, the second dispensing nozzle 410b opens the at least one second nozzle hole 411a. The paste P is discharged onto the silicon wafer W through the wafer. As a result, the second electrode pattern 403b is formed on the silicon wafer W. As shown in FIG. In this case, since the second dispensing nozzle 410b is fixedly mounted on the second table T2, the pair of second linear motion guides 448b need not be used.

On the other hand, when the second stage S2 is stopped, the second dispensing nozzle 410b mounted on the second gantry 416b is provided with a pair of second linear motion guides provided on the second table T2. The second electrode pattern 403b is formed on the silicon wafer W mounted on the stationary second stage S2 while moving in the horizontal direction (A2 direction in FIG. 4B) along 448b.

In the electrode pattern forming apparatus 400 according to the first exemplary embodiment of the present invention, relative movement between the first dispensing nozzle 410a and the first stage S1 and the second dispensing nozzle 410b and the second stage S2 are performed. The first and second electrode patterns 403a and 403b are sequentially formed on the silicon wafer W through the relative motion between them.

4C is a schematic cross-sectional view of a dispensing nozzle according to a first embodiment of the present invention, and FIG. 4D is a schematic cross-sectional view of a dispensing nozzle according to a second embodiment of the present invention. to be.

4C and 4D, the dispensing nozzle 410 according to the first and second embodiments of the present invention is commonly applied to the first dispensing nozzle 410a and the second dispensing nozzle 410b. . In the case of the dispensing nozzle 410 according to the first embodiment shown in FIG. 4C, the first ribs 412a1 and 412b1 constituting the dispensing nozzle 410 have a height H1 and a width M on the lower surface thereof. And at least one nozzle hole 411a, 411b (collectively referred to as "411"), and the second lip 412a2, 412b2 constituting the dispensing nozzle 410 has a nozzle hole at its lower surface. 411 is not provided. On the other hand, in the dispensing nozzle 410 according to the second embodiment shown in FIG. 4D, the first lips 412a1 and 412b1 and the second lips 412a2 and 412b2 constituting the dispensing nozzle 410 One or more nozzle holes 411 each having a height H1 and a width M on its lower surface. That is, the height H2 of the nozzle hole 411 according to the embodiment of FIG. 4D is twice as high as the height H1 of the nozzle hole 411 according to the embodiment of FIG. 4C. The number of one or more nozzle holes 411 shown in the above-described embodiments of 4c and 4d corresponds to the number of the first electrode pattern 403a and the second electrode pattern 403b, respectively. For example, when the first electrode pattern 403a is ten fingers and the second electrode pattern 403b is two busbars, the number of nozzle holes 411 of the first dispensing nozzle 410 is ten. The number of nozzle holes 411 of the second dispensing nozzle 410 is two. Further, in the prior art using the screen printing method, the widths of the first electrode pattern 403a and the second electrode pattern 403b are approximately 150 to 200 µm (hereinafter referred to as "existing width"), and the interval between the electrode patterns ( Hereinafter referred to as "existing spacing" is approximately 3 mm. However, in the present invention, since the width M of the nozzle hole 411 and the gap G between the nozzle holes 411 are easily adjusted to be larger or smaller than the existing width and the existing gap, the width of the electrode pattern of the solar cell is easy. It is possible to make various gaps between the electrode and the electrode pattern.

FIG. 4E schematically illustrates an electrode pattern formed when the paste P is ejected onto the silicon wafer W using the dispensing nozzles according to the first and second embodiments of the present invention shown in FIGS. 4C and 4D, respectively. It is a figure shown.

Referring to FIG. 4E, (1) is a case where the paste P is discharged onto the silicon wafer W using the dispensing nozzle 410 according to the first embodiment of the present invention shown in FIG. 4C. , (2) is a case where the paste P is discharged onto the silicon wafer W using the dispensing nozzle 410 according to the second embodiment of the present invention shown in FIG. Comparing (1) and (2), the formed electrode pattern 403 has the same width m, but the height h2 of the electrode pattern 403 of (2) is the pole pattern 403 of (1). It can be seen that it is approximately twice higher than the height h1 of. This result indicates that the height H2 of the nozzle hole 411 of the dispensing nozzle 410 according to the second embodiment of the present invention shown in FIG. At twice the height H1 of the nozzle hole 411 of the fencing nozzle 410, the dispensing nozzle 410 moves along the horizontal direction (the A2 direction shown in FIGS. 4C and 4D) and the silicon wafer W This is because the amount of the paste P discharged onto the image is doubled. The higher the height of the electrode pattern 403, the wider the multi-faceted area serving as the electrical passage, the lower the resistance and the higher the electrical conductivity.

4F is a schematic cross-sectional view of an electrode pattern forming apparatus of a solar cell using a multi-dispensing method according to a second embodiment of the present invention, and FIG. 4G is a second embodiment of the present invention shown in FIG. 4F. Figure is a side cross-sectional view schematically showing an electrode pattern forming apparatus of a solar cell using a multi-dispensing method according to the example.

4F and 4G, the electrode pattern forming apparatus 400 of the solar cell using the multi-dispensing method according to the second embodiment of the present invention forms a front electrode of the solar cell on the silicon wafer (W). A first dispensing nozzle 410a having one or more first nozzle holes 411a (see FIGS. 4C and 4D) for forming the first electrode pattern 403a; A second dispensing nozzle 410b having at least one second nozzle hole 411b (see FIGS. 4C and 4D) for forming a second electrode pattern 403b constituting the front electrode; And a stage S on which the silicon wafer W is mounted, which is capable of moving forward and backward relative to the first dispensing nozzle 410a and the second dispensing nozzle 410b and capable of rotating movement. Include.

In the embodiments of FIGS. 4F and 4G described above, the first dispensing nozzle 410a is detachably mounted to the first gantry 416a. The first gantry 416a is mounted on a pair of first linear motion guides 448a to enable forward and backward movements. A pair of first linear motion guides 448a are located on the table T. Here, the use of a pair of first linear motion guides 448 is optional. In addition, the second dispensing nozzle 410b is detachably mounted to the second gantry 416b. The second gantry 416b is mounted on a pair of second linear motion guides 448b to enable forward and backward movement. A pair of second linear motion guides 448b is located on the table T. Here, the use of a pair of second linear motion guides 448b is optional. The silicon wafer W is mounted on the stage S, which is capable of moving forward and backward. The stage S is movable relative to the first dispensing nozzle 410a and the second dispensing nozzle 410b of the present invention, which is movably mounted on the table T.

As shown in FIGS. 4F and 4G, when the stage S moves along the horizontal direction (the A1 direction in FIG. 4G) on the table T, the first dispensing nozzle 410a moves to at least one first nozzle hole. The paste P is discharged onto the silicon wafer W through 411a. As a result, the first electrode pattern 403a is formed on the silicon wafer (W). In this case, since the first dispensing nozzle 410a is fixedly mounted on the first table T1, the pair of first linear motion guides 448a need not be used.

On the other hand, when the stage S stops, the first dispensing nozzle 410a mounted on the first gantry 416a is along a pair of first linear motion guides 448a provided on the table T. The first electrode pattern 403a is formed on the silicon wafer W mounted on the stationary stage S while moving in the horizontal direction (A2 direction in FIG. 4G).

As described above, after the first electrode pattern 403a is formed on the silicon wafer W, since the first electrode pattern 403a and the second electrode pattern 403b should be formed perpendicular to each other, the silicon wafer W Mounted stage S rotates by 90 °.

Thereafter, when the stage S continues to move along the horizontal direction (the A1 direction in FIG. 4G) on the table T, the second dispensing nozzle 410b moves through the one or more second nozzle holes 411a. Paste P is discharged on (W). As a result, the second electrode pattern 403b is formed on the silicon wafer W. As shown in FIG. In this case, since the second dispensing nozzle 410b is fixedly mounted on the second table T2, the pair of second linear motion guides 448b need not be used.

On the other hand, when the stage S is stopped (in this case, the stage S rotates by 90 °), the second dispensing nozzle 410b mounted on the second gantry 416b is provided on the table T. The second electrode pattern 403b on the silicon wafer W mounted on the stationary stage S while moving in a horizontal direction (A2 direction in FIG. 4G) along a pair of second linear motion guides 448b. ).

In the electrode pattern forming apparatus 400 according to the second embodiment of the present invention, the first and second electrodes are formed through relative movement between the first dispensing nozzle 410a and the second dispensing nozzle 410b and the stage S. FIG. Patterns 403a and 403b are sequentially formed on silicon wafer W. As shown in FIG.

As described above, in the electrode pattern forming apparatus 400 according to the first and second embodiments of the present invention, the first and second dispensing nozzles 410a and 410b are in contact with the silicon wafer W in a non-contact state. Since the first and second electrode patterns 403a and 403b are discharged to form P, the possibility of damage or breakage of the silicon wafer W is eliminated as compared with the prior art, and the number of processes and time for forming the electrode pattern is increased. Significantly reduced.

4H illustrates a perspective view of a typical dispensing nozzle according to one embodiment of the invention.

4H, a typical dispensing nozzle 410 according to one embodiment of the invention includes a first lip 412a; A second lip 412b provided opposite the first lip 412a; And one or more nozzle holes 411 (see FIGS. 4C and 4D) formed in the bottom surface of one or both of the first lip 412a and the second lip 412b. On top of the dispensing nozzle 410 is provided a hanger 413 for mounting to the gantry 416a or 416b (see FIGS. 4A and 4F), the first lip 412a and the second lip 412b. The paste supply member 415 for supplying the paste P to any one (first lip 412a in FIG. 4H) is connected.

The conventional dispensing nozzle 410 according to the embodiment of the present invention illustrated in FIG. 4H described above may be used when the paste P has a low viscosity. However, when the paste P has a high viscosity, since a high pressure pumping operation is required, the quantitative or uniform discharge of the high viscosity paste P through one or more nozzle holes 411 may not be easy due to vibration.

4I is a perspective view of a dispensing nozzle according to another embodiment of the present invention.

Referring to FIG. 4I, the dispensing nozzle 410 according to another embodiment of the present invention may include a first lip 412a and a second lip of the conventional dispensing nozzle 410 of the present invention shown in FIG. 4H. A heater 414 provided on an outer surface of 412b and supplying heat to the first lip 412a and the second lip 412b; A heat shield member 416 provided on an outer surface of the heater 414 to block heat emitted from the heater 414; And a temperature sensor 418 provided on an upper portion of any one of the first lip 412a and the second lip 412b. In the embodiment of FIG. 4I, the temperature sensors 418 are illustrated in pairs, but those skilled in the art will fully appreciate that the temperature sensors 418 can be increased or decreased as needed. In addition, the heater 414 is preferably implemented as a plate-type heater.

In the dispensing nozzle 410 according to the embodiment of FIG. 4I, since the first lip 412a and the second lip 412b are heated by the heater 414, the first lip 412a and the second lip 412b. Also, the high viscosity paste P in Fig. 1 may be heated to discharge the high viscosity paste P quantitatively or uniformly through one or more nozzle holes 411 without using high pressure pumping.

5A is a flowchart illustrating a method of forming an electrode pattern of a solar cell using a multi-dispensing method according to an embodiment of the present invention.

Referring to FIG. 5A together with FIGS. 4A to 4D, an electrode pattern forming method 500 of a solar cell using a multi-dispensing method according to an embodiment of the present invention may include a) a first configuration of a front electrode of the solar cell; And providing (510) first and second dispensing nozzles (410a, 410b) having one or more nozzle holes each having a width (M) corresponding to the width of the second electrode patterns (403a, 403b). b) forming the first electrode pattern 403a on the silicon wafer W by moving the first stage S1 on which the silicon wafer W is mounted relative to the first dispensing nozzle 410a. 520; c) rotating (530) the silicon wafer (W) on which the first electrode pattern (403a) is formed by 90 °; d) transferring (540) the silicon wafer (W) onto a second stage (S2); And e) forming the second electrode pattern 403b on the silicon wafer W by moving the second stage S2 relative to the second dispensing nozzle 410b. .

5B is a flowchart illustrating a method of forming an electrode pattern of a solar cell using the multi-dispensing method according to another embodiment of the present invention.

Referring to FIG. 5B together with FIGS. 4F to 4G, an electrode pattern forming method 500 of a solar cell using a multi-dispensing method according to another embodiment of the present invention may include a) forming a front electrode of the solar cell; Providing (510) the first and second dispensing nozzles 410a, 410b with one or more nozzle holes each having a width M corresponding to the width of the first and second electrode patterns 403a, 403b. ); b) forming the first electrode pattern 403a on the silicon wafer W by moving the stage S on which the silicon wafer W is mounted relative to the first dispensing nozzle 410a. ); c) rotating (530) the silicon wafer (W) on which the first electrode pattern (403a) is formed by 90 °; And d) forming the second electrode pattern 403b on the silicon wafer W by moving the stage S relative to the second dispensing nozzle 410b.

5A and 5B, the first electrode pattern 403a and the second electrode pattern 403b may each be a plurality of finger vias or one or more bus bars.

Since various examples can be made in the configurations and methods described and illustrated herein without departing from the scope of the present invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be illustrative, and not intended to limit the invention. no. Therefore, the scope of the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

1 is a view schematically showing the basic structure of a typical solar cell.

2 is a schematic cross-sectional view of a single crystal silicon solar cell according to the prior art.

FIG. 3A is a view schematically illustrating a screen printing method for forming an electrode pattern including a plurality of finger bars and one or more bus bars of a silicon solar cell according to the prior art.

3B is a view showing the steps of the screen printing method according to the prior art.

3C is a view showing photographs of electrode patterns formed on the silicon wafer W using the screen printing method of the prior art.

4A is a schematic cross-sectional view of an electrode pattern forming apparatus of a solar cell using the multi-dispensing method according to the first embodiment of the present invention.

FIG. 4B is a schematic cross-sectional view of the electrode pattern forming apparatus of the solar cell using the multi-dispensing method according to the first embodiment of the present invention shown in FIG. 4A.

4C is a schematic cross-sectional view of a dispensing nozzle according to a first embodiment of the present invention.

4D is a schematic cross-sectional view of a dispensing nozzle according to a second embodiment of the present invention.

FIG. 4E schematically illustrates an electrode pattern formed when the paste P is ejected onto the silicon wafer W using the dispensing nozzles according to the first and second embodiments of the present invention shown in FIGS. 4C and 4D, respectively. It is a figure shown.

4F is a schematic cross-sectional view of an electrode pattern forming apparatus of a solar cell using the multi-dispensing method according to the second embodiment of the present invention.

4G is a schematic cross-sectional view of an electrode pattern forming apparatus of a solar cell using the multi-dispensing method according to the second embodiment of the present invention shown in FIG. 4F.

4H illustrates a perspective view of a typical dispensing nozzle according to one embodiment of the invention.

4I is a perspective view of a dispensing nozzle according to another embodiment of the present invention.

5A is a flowchart illustrating a method of forming an electrode pattern of a solar cell using the multi-dispensing method according to an embodiment of the present invention.

5B is a flowchart illustrating a method of forming an electrode pattern of a solar cell using the multi-dispensing method according to another embodiment of the present invention.

Claims (14)

In the electrode pattern forming apparatus of a solar cell using a multi-dispensing method, A first dispensing nozzle having at least one first nozzle hole for forming a first electrode pattern constituting a front electrode of a solar cell on a silicon wafer (W); A first stage on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the first dispensing nozzle; A second dispensing nozzle having at least one second nozzle hole for forming a second electrode pattern constituting the front electrode; A second stage on which the silicon wafer (W) is mounted and capable of moving forward and backward relative to the second dispensing nozzle; And After the first electrode pattern is formed by the first dispensing nozzle, a transfer device for transferring the silicon wafer (W) from the first stage to the second stage Electrode pattern forming apparatus of a solar cell comprising a. The method of claim 1, The transfer device is an electrode pattern forming apparatus of a solar cell implemented by a robot arm or a conveyor. The method of claim 1, And the first electrode pattern and the second electrode pattern are a plurality of finger bars or at least one bus bar, respectively. The method according to any one of claims 1 to 3, The electrode pattern forming apparatus of the solar cell A pair of first linear motion guides for moving forward and backward of the first gantry on which the first dispensing nozzle is mounted; A first table T1 on which the pair of first linear motion guides are mounted; A pair of second linear motion guides for moving forward and backward of the second gantry on which the second dispensing nozzle is mounted; And A second table T2 on which the pair of second linear motion guides are mounted; In addition, The first stage S1 moves relative to the first dispensing nozzle on the first table T1, The second stage S2 moves relative to the second dispensing nozzle on the second table T2. Electrode pattern forming apparatus of a solar cell. The method according to any one of claims 1 to 3, The first and second dispensing nozzles are respectively First lip; A second lip provided opposite the first lip; At least one nozzle hole formed in a lower surface of one or both of the first lip and the second lip; And A paste supply member connected to any one of the first lip and the second lip and supplying a paste P; Electrode pattern forming apparatus of a solar cell comprising a. The method according to any one of claims 1 to 3, The first and second dispensing nozzles are respectively First lip; A second lip provided opposite the first lip; At least one nozzle hole formed in a lower surface of one or both of the first lip and the second lip; A heater provided on an outer surface of the first lip and the second lip, the heater supplying heat to the first lip and the second lip; A heat blocking member provided on an outer surface of the heater to block heat emitted from the heater; A temperature sensor provided on an upper portion of either the first lip or the second lip; And A paste supply member connected to any one of the first lip and the second lip and supplying a paste P; Electrode pattern forming apparatus of a solar cell comprising a. In the electrode pattern forming apparatus of a solar cell using a multi-dispensing method, A first dispensing nozzle having at least one first nozzle hole for forming a first electrode pattern constituting a front electrode of a solar cell on a silicon wafer (W); A second dispensing nozzle having at least one second nozzle hole for forming a second electrode pattern constituting the front electrode; And The stage (S) on which the silicon wafer (W) is mounted, which is capable of moving forward and backward relative to the first dispensing nozzle and the second dispensing nozzle, and capable of rotational movement. Electrode pattern forming apparatus of a solar cell comprising a. The method of claim 7, wherein And the first electrode pattern and the second electrode pattern are a plurality of finger bars or at least one bus bar, respectively. The method according to claim 7 or 8, The electrode pattern forming apparatus of the solar cell A pair of linear motion guides for moving forward and backward the first gantry on which the first dispensing nozzle is mounted and the second gantry on which the second dispensing nozzle is mounted; A table (T) on which the pair of linear motion guides are mounted; And A pair of second linear motion guides for forward and backward movement of a second gantry on which the second dispensing nozzle is mounted In addition, The stage S moves relative to the first dispensing nozzle and the second dispensing nozzle on the table T. Electrode pattern forming apparatus of a solar cell. The method according to claim 7 or 8, The first and second dispensing nozzles are respectively First lip; A second lip provided opposite the first lip; At least one nozzle hole formed in a lower surface of one or both of the first lip and the second lip; And A paste supply member connected to any one of the first lip and the second lip and supplying a paste P; Electrode pattern forming apparatus of a solar cell comprising a. The method according to claim 7 or 8, The first and second dispensing nozzles are respectively First lip; A second lip provided opposite the first lip; At least one nozzle hole formed in a lower surface of one or both of the first lip and the second lip; A heater provided on an outer surface of the first lip and the second lip, the heater supplying heat to the first lip and the second lip; A heat blocking member provided on an outer surface of the heater to block heat emitted from the heater; A temperature sensor provided on an upper portion of either the first lip or the second lip; And A paste supply member connected to any one of the first lip and the second lip and supplying a paste P; Electrode pattern forming apparatus of a solar cell comprising a. In the method of forming an electrode pattern of a solar cell using a multi-dispensing method, a) providing first and second dispensing nozzles having one or more nozzle holes each having a width M corresponding to a width of the first and second electrode patterns constituting the front electrode of the solar cell; b) forming a first electrode pattern on the silicon wafer (W) by moving the first stage (S1) on which the silicon wafer (W) is mounted relative to the first dispensing nozzle; c) rotating the silicon wafer W on which the first electrode pattern is formed by 90 °; d) transferring the silicon wafer (W) onto a second stage (S2); And e) forming the second electrode pattern 403b on the silicon wafer W by moving the second stage S2 relative to the second dispensing nozzle. Electrode pattern forming method of a solar cell comprising a. In the method of forming an electrode pattern of a solar cell using a multi-dispensing method, a) providing first and second dispensing nozzles having one or more nozzle holes each having a width M corresponding to a width of the first and second electrode patterns constituting the front electrode of the solar cell; b) forming the first electrode pattern (403a) on the silicon wafer (W) by moving the stage (S) on which the silicon wafer (W) is mounted relative to the first dispensing nozzle; c) rotating the silicon wafer W on which the first electrode pattern is formed by 90 °; And d) forming the second electrode pattern 403b on the silicon wafer W by moving the stage S relative to the second dispensing nozzle. Electrode pattern forming method of a solar cell comprising a. The method according to claim 12 or 13, And the first electrode pattern and the second electrode pattern are each a plurality of finger vias or one or more bus bars.

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