KR101160641B1 - Method and apparatus for forming selective emitter of solar cell - Google Patents

Abstract

A method and apparatus for forming a selective emitter of a solar cell are disclosed. The apparatus includes: transfer means for transferring a substrate having an upper surface of a first emitter layer formed by diffusion of n-type impurities; A table receiving the substrate from the transfer means and supporting the substrate; Preheating means for preheating the substrate supported on the table; And laser irradiation means positioned at an upper side of the table and irradiating a laser to a portion of the first emitter layer to form a second emitter layer formed by further diffusing the n-type impurity.

Description

Method and apparatus for forming selective emitter of solar cell {Method and apparatus for forming selective emitter of solar cell}

The present invention relates to a method and apparatus for forming a selective emitter of a solar cell.

Recently, as the environmental pollution problem becomes serious, researches on renewable energy that can reduce environmental pollution have been actively conducted. Among renewable energy, in particular, attention is focused on solar cells that can produce electrical energy using solar energy. However, in order for a solar cell to be applied to an actual industry, the photoelectric conversion efficiency of the solar cell must be high and its manufacturing price must be low.

In terms of photoelectric conversion efficiency, the theoretical marginal efficiency of silicon solar cells is not so high, so there is a limit to increase the photoelectric conversion efficiency of actual solar cells. It is reported to have.

However, when mass production of solar cells, the average photoelectric conversion efficiency of solar cells is actually difficult to exceed 17%. Therefore, there is a demand for a high efficiency production method that can be applied in an automated mass production process line of 30MW or more per year.

The present invention provides a method and apparatus for forming a selective emitter of a solar cell, which can stably form a selective emitter while improving the photoelectric conversion efficiency of the solar cell through selective emitter formation.

According to an aspect of the invention, the transfer means for transferring the substrate formed on the upper surface of the first emitter layer formed by the diffusion of the n-type impurities; A table receiving the substrate from the transfer means and supporting the substrate; Preheating means for preheating the substrate supported on the table; And laser irradiation means positioned to be spaced above the table and irradiating a laser to a portion of the first emitter layer to form a second emitter layer formed by further diffusing the n-type impurity. An optional emitter forming apparatus for a cell is provided.

The preheating means may preheat the substrate through the table.

The second emitter layer may include a bus bar layer formed at a position where a bus bar electrode is to be formed, and a finger layer formed at a position at which a finger electrode is to be formed, wherein the laser irradiation means includes the bus bar layer. First laser irradiation means movable in a first direction to form a light source; And second laser irradiation means movable in a second direction crossing the first direction to form the finger layer.

The table may include a first table and a second table that are continuously arranged in series, wherein the first laser irradiation means is located above the first table to form the busbar layer, and the second laser irradiation. The means may be located above the second table to form the finger layer.

The laser irradiation means may be movable in a first direction to form the busbar layer, and may also be movable in a second direction crossing the first direction to form the finger layer.

The conveying means may comprise a conveyor belt, wherein the table may be disposed below the conveyor belt.

The electronic device may further include a substrate detection sensor positioned at the front of the table to sense a transfer of the substrate, and adjusting an operation of the conveyor belt to stop the substrate at the table.

It may further include an alignment sensor unit for detecting the alignment state of the substrate located on the table, the laser irradiation means may be corrected in accordance with the alignment state of the substrate.

The alignment sensor unit may be positioned below the table, and the table may be provided with a transparent area so that the alignment sensor unit can detect the alignment state of the substrate.

The sensor unit may include a first sensor detecting a rear surface of the substrate; A second sensor for sensing a side surface of the substrate; And a third sensor configured to detect a rotation state of the substrate.

The first sensor, the second sensor, and the third sensor may include a lighting unit and a camera, respectively.

In order to prevent movement of the substrate located on the table, a negative pressure hole for supplying a negative pressure may be formed in the table.

According to another aspect of the invention, the step of placing a substrate formed on the upper surface of the first emitter layer formed by the diffusion of the n-type impurities on the table; Preheating the substrate located on the table; And irradiating a laser to a portion of the first emitter layer to form a second emitter layer formed by further diffusing the n-type impurity.

The preheating step may be performed through the table.

The second emitter layer may include a bus bar layer formed at a position where a bus bar electrode is to be formed, and a finger layer formed at a position at which a finger electrode is to be formed, and irradiating the laser may include: First laser irradiation means moving in a first direction to form; And second laser irradiating means moving in a second direction crossing the first direction to form the finger layer.

On the other hand, the step of irradiating the laser, is performed by the laser irradiation means which is movable in a first direction to form the bus bar layer, and also movable in a second direction crossing the first direction to form the finger layer. May be

The laser irradiation step may be performed by a laser irradiation means spaced apart from the upper side of the substrate, the step of detecting the alignment of the substrate located on the table; And correcting the position of the laser irradiation means according to the alignment state of the substrate.

Sensing the alignment of the substrate may include illuminating the substrate; And photographing an end of the substrate.

Detecting the alignment of the substrate located on the table comprises: detecting a front surface of the substrate; Sensing a side of the substrate; And detecting a rotation state of the substrate.

A negative pressure hole is formed in the table, and may further include supplying a negative pressure to the substrate to fix the substrate on the table.

According to a preferred embodiment of the present invention, it is possible to stably form the selective emitter while improving the photoelectric conversion efficiency of the solar cell through the formation of the selective emitter.

1 is a flow chart showing a selective emitter forming method of a solar cell according to an aspect of the present invention.
2 and 3 are views showing the coating of impurities on the surface of the substrate.
4 is a diagram showing the application of thermal energy to a substrate to form a first emitter layer.
5 is a cross-sectional view showing a substrate on which a first emitter layer is formed.
6 is a view showing a state of irradiating a laser to form a second emitter layer.
7 is a sectional view of a substrate on which a second emitter layer is formed.
8 and 9 are graphs showing the change of diffusion coefficient with temperature.
10 is a plan view showing a state in which a bus bar layer and a finger layer are formed.
11 is a plan view showing a state in which a busbar electrode and a finger electrode are formed.
12 is a side view showing an embodiment of a selective emitter forming apparatus of a solar cell according to another aspect of the present invention.
13 to 15 are perspective views showing various modified embodiments of the selective emitter forming apparatus of the solar cell according to another aspect of the present invention.
16 is a plan view of the transfer assembly.
17 is a perspective view of a table assembly.
FIG. 18 is a plan view illustrating a state in which a table is removed from FIG. 17. FIG.
19 is a side view of the table assembly.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, a preferred embodiment of the method and apparatus for forming a selective emitter of a solar cell according to the present invention will be described in detail with reference to the accompanying drawings, in the description with reference to the accompanying drawings, the same or corresponding components are the same drawings The numbering and duplicate description thereof will be omitted.

First, a method of forming a selective emitter of a solar cell according to an aspect of the present invention will be described with reference to FIGS. 1 to 11.

First, the substrate 10 having the first emitter layer 14 formed by diffusion of the n-type impurity 12 is formed on the table (see 200 of FIG. 12) on the table (S100). The table 200 supports the substrate 10, and a process of forming a selective emitter on the substrate 10 while the substrate 10 is supported by the table 200 is performed. As such, the process of forming the selective emitter in a state where the substrate 10 is fixed on the table 200 may be performed to stably form the selective emitter without fear of vibration in the substrate 10. .

The substrate 10 may be a p-type silicon substrate doped with boron ions, and a first emitter layer 14 is already formed on the surface thereof. That is, according to the present embodiment, the selective emitter, that is, the second emitter layer 16 is formed through a process separate from the process of forming the first emitter layer 14.

Here, the first emitter layer 14 corresponds to an n layer formed by diffusion of impurities 12 such as phosphorous. In order to fabricate the substrate 10, a solution of an impurity 12 such as phosphorus is coated on the surface of the substrate 10 (see FIGS. 2 and 3), and thermal energy E1 is applied to the surface of the silicon substrate 10. Can be used (see FIG. 4). When thermal energy E1 is applied to the surface of the silicon substrate 10, the impurities 12 may diffuse into the silicon substrate 10 to form the first emitter layer 14 (see FIG. 5).

Next, as shown in FIG. 6, after preheating the substrate 10 positioned on the table (200 of FIG. 12) (S200), the laser L is applied to a portion of the first emitter layer 14. Irradiation forms a second emitter layer 16 in which the n-type impurity 12 is further diffused (S300). That is, after a predetermined energy is applied to the entire substrate 10, the laser L is irradiated to a part of the first emitter layer 14 in which the n-type impurity 12 has already been diffused.

At this time, in order to form the second emitter layer 16 in the partial region of the first emitter layer 14, the energy E3 applied to the substrate 10 by preheating and the energy applied by the laser L are applied. The sum of (E2) needs to be greater than the energy (E1) that was used to form the first emitter layer 14 (E2 + E3> E1). At this time, if an energy greater than the energy E1 used to form the first emitter layer 14 using only the laser L is applied, the laser L having an excessive intensity is part of the substrate 10. In this case, there is a concern that damage, such as surface explosion, may occur at a corresponding portion of the substrate 10 as a result.

In order to solve this problem, in the present embodiment, the preheating process is performed separately from the irradiation of the laser L, so that the predetermined energy E3 is applied to the entire substrate 10 through preheating, and is supplied by preheating. In addition to the energy E3, the remaining necessary energy E2 is to be supplied through laser irradiation. As a result, it is possible to reduce the excessive energy difference between the region to which the laser L is irradiated and the region not to be irradiated, thereby preventing damage to the substrate 10. At this time, the preheating process and the laser irradiation process may be performed sequentially or may be performed at the same time.

As described above, by preheating and laser irradiation, energy E2 + E3 larger than the energy E1 used to form the first emitter layer 14 is transferred to a portion of the first emitter layer 14. When applied, a phenomenon in which the n-type impurity 12 is further diffused occurs in a region where the laser L is irradiated, whereby a second emitter layer 16 is formed in a portion of the first emitter layer 14. (See FIG. 7). This principle will be described in more detail below.

The diffusion of atoms in a solid occurs from a high concentration region to a low concentration region when the concentration of atoms is uneven, until the concentration of atoms is uniform throughout the solid by thermal motion. The equation which is the basis of the diffusion phenomenon according to the first law of the peak that the diffusion amount is proportional to the concentration gradient is as follows.

In Equation 1, J represents the diffusion amount (ie, the amount of diffusion material passing through the unit area), and D is the diffusion coefficient. In addition, C represents the concentration of the diffusion material, x represents the moving distance of the diffusion material on the Y axis.

At this time, the diffusion coefficient rapidly increases as the temperature is increased, and is expressed as a function below.

In Equation 2, D ₀ is a temperature insensitive constant, k is a Boltzmann constant, and T is a temperature. Q is called activation energy and has a value of about 2 to 5 eV depending on the substance. Graphs showing changes in diffusion coefficient with temperature based on Equation 2 are shown in FIGS. 8 and 9. For example, when Q = 2 eV and D0 = 8 x 10 ^-5 m 2 / sec, D ≒ 10 ^-38 m 2 / sec at 300 ° K, but at T = 1500 ° K, D = 10 ^-11 m 2 Increased rapidly to / sec.

Therefore, as shown in FIG. 8, assuming that two energy E1 and E2 + E3 having different temperatures are respectively injected to two points of the silicon substrate 10, the diffusion coefficients for the two regions are different from each other as D ₁ and D ₂ . Because different (i.e., the diffusion coefficient increases as the temperature increases), the degree of arrival of the impurity 12 is different, so that the second emitter layer in some regions of the first emitter layer 14 as shown in FIG. (16) is formed so that both can be distinguished from each other.

 As shown in FIG. 9, the graph illustrated in FIG. 8 may be represented as a graph representing a relationship between a log function and the inverse of temperature. Equation (2) is represented by a logarithmic function corresponding to the graph shown in FIG.

Meanwhile, as shown in FIG. 10, the second emitter layer 16 selectively formed on the first emitter layer 14 is formed at a position where a bus bar electrode (see 13a of FIG. 11) of the solar cell is to be formed. The bus bar layer 16a and a finger layer 16b formed at a position where a finger electrode (see 13b of FIG. 11) will be formed may be included. In order to form both the busbar layer 16a and the finger layer 16b, the above-described laser irradiation process includes a first process for forming the busbar layer 16a and a second process for forming the finger layer 16b. It can be divided into.

In this case, the first process and the second process may be performed by one laser irradiation means, or may be performed by two laser irradiation means. The structure of the specific device for this will be described later. In FIG. 11, a finger electrode 13b is formed on a finger layer (see 16b of FIG. 10), and a busbar electrode 13a is formed on a busbar layer (see 16a of FIG. 10). The anti-reflection film 11 is formed on the remaining portion where the finger electrode 13b and the busbar electrode 13a are not formed.

The method of forming a selective emitter of a solar cell according to an aspect of the present invention has been described above. Hereinafter, the selective emitter forming apparatus of a solar cell according to another aspect of the present invention will be described. The method of forming the selective emitter of the solar cell described above may be performed through the same or similar device as the selective emitter forming apparatus of the solar cell to be described below. Therefore, the description of the operation of each device to be described below can be applied to the above-described selective emitter forming method of the solar cell.

As shown in FIG. 12, the selective emitter forming apparatus of the solar cell according to another aspect of the present invention includes a transfer means 100a for transferring the substrate 10 on which the first emitter layer (see 14 of FIG. 7) is formed. 100b, 100c in FIG. 16, hereafter referred to as 100); A table 200 for supporting the supplied substrate 10; Preheating means 300 for preheating the substrate 10; The laser irradiation means 400 which forms a 2nd emitter layer (refer 16 of FIG. 7) by which a laser is irradiated to the some area | region of the 1st emitter layer 14 and is formed by further spreading n type impurity has a main structure. .

The transfer means 100 performs a function of supplying the substrate 10 on which the first emitter layer 14 is formed to the table 200 to be described later. The transfer means 100 may be a robot arm (not shown) or the like, but in this embodiment, it is to present a conveyor belt that is advantageous for continuous production. As in the case of this embodiment, by using the in-line method for transferring the substrate 10 by using a conveyor belt, it is possible to improve the production yield by enabling a continuous processing.

The table 200 supports the substrate 10 supplied through the conveying means 100, and in the state where the substrate 10 is supported by the table 200, a second emitter layer ( The process of forming 16) of FIG. 7 is performed. As such, the process of forming the second emitter layer 16 selectively in a state where the substrate 10 is fixed on the table 200 is performed, thereby stably selecting the emitter without fear of vibration in the substrate 10. Can be formed.

On the other hand, the above-described conveying means 100 and the table 200, etc. may exist in one assembly form as shown in FIG. 16, which will be referred to as a conveying assembly 1000. The detailed structure of the transfer assembly 1000 will be described later.

Meanwhile, the substrate 10 supplied to the table 200 by the transfer means 100 may be a p-type silicon substrate doped with boron ions, and the first emitter layer (see 14 in FIG. 7) is already formed on the surface thereof. Formed. As described above, the process of preparing the substrate 10 on which the first emitter layer 14 is already formed is as described above, and thus a detailed description thereof will be omitted.

The preheating means 300 performs a function of preheating the substrate 10 supported by the table 200. A predetermined energy (see E3 in FIG. 6) is applied to the entire substrate 10 through the preheating means 300, and the remaining necessary energy (see E2 in FIG. 6) in addition to the energy E3 supplied by the preheating will be described later. By supplying through the laser irradiation means 400, it is possible to reduce the excessive energy difference between the region to which the laser (L) is irradiated and the other region. In this way, as the laser of excessive intensity is irradiated intensively on a portion of the substrate 10, the possibility of damage occurring at the corresponding portion of the substrate 10 can be reduced as described above.

At this time, the preheating means 300 may preheat the substrate 10 through the table 200. That is, the preheating means 300 may heat the table 200 so that the heated table 200 preheats the substrate 10. In this case, the preheating means 300 may use a hot wire or the like embedded in the table 200 as shown in FIG. 12.

Meanwhile, in the present exemplary embodiment, the case in which the substrate 10 is preheated through the table 200 is illustrated as an example, but is not necessarily limited thereto, and the substrate 10 may be directly heated separately from the table 200. It is also possible to use non-contact preheating means.

The laser irradiation means 400 is spaced apart from the upper side of the table 200 and irradiates the laser L to a predetermined position of the substrate 10 supported by the table 200. In the region where the laser L is irradiated, impurities are further diffused to form a second emitter layer (see 16 in FIG. 7).

Meanwhile, as described above with reference to FIG. 10, the second emitter layer 16 selectively formed on the first emitter layer (see 14 of FIG. 7) may include a bus bar electrode (see 13a of FIG. 11). The bus bar layer 16a may be formed at a position to be formed, and the finger layer 16b may be formed at a position at which a finger electrode (see 13b of FIG. 11) is to be formed. In order to form both the busbar layer 16a and the finger layer 16b, the laser irradiation process is divided into a first process for forming the busbar layer 16a and a second process for forming the finger layer 16b. Can be.

In this case, both the first process and the second process may be performed by one laser irradiation means 400, or may be performed by being divided by two laser irradiation means (see 400a and 400b of FIGS. 13 and 15). There will be. 13 shows a first laser irradiation means 400a which is movable in one direction (for example, x-axis direction) to perform a first process, and another direction (for example, y-axis direction) to perform a second process. There is shown a second laser irradiation means 400b that can be moved by.

Meanwhile, FIG. 14 shows one laser irradiation means 400 which is movable in both the x-axis direction and the y-axis direction so as to perform both the first process and the second process.

On the other hand, as shown in FIG. 15, the first process and the second process may be divided by using two transfer assemblies 1000a and 1000b and two laser irradiation means 400a and 400b arranged in series with each other. Could be That is, in the table 200a of the transfer assembly 1000a located at the front side, the first process is performed by using the first laser irradiation means 400a which is movable in the x-axis direction, and the table of the transfer assembly 1000b positioned at the rear side. At 200b, the second process may be performed using the second laser irradiation means 400b that is movable in the y-axis direction.

In FIG. 15, two conveying assemblies 1000a and 1000b are slightly spaced apart for convenience of illustration. However, when two conveying assemblies 1000a and 1000b are disposed in succession to each other, a conveyor positioned between two tables is provided. The belt may be transported continuously by the belt.

Hereinafter, the structure of the transfer assembly 1000 will be described in more detail with reference to FIGS. 16 to 19. Since the structures of the two transfer assemblies 1000a and 1000b shown in FIG. 15 are also the same, a separate description thereof will not be provided.

The transfer assembly 1000 receives the substrate 10, supports the substrate 10 while the laser irradiation is performed, and transfers the substrate 10 on which the laser irradiation is completed to a subsequent process. FIG. 16 illustrates a table plate 500 having a substantially plate-like shape, a front conveying means 100a, a table assembly TA, a rear conveying means 100b, and the like, which are positioned on the table frame 500. Is shown.

The front transfer means 100a performs a function of supplying the substrate 10 to the table assembly TA, and the rear transfer means 100b performs a function of transferring the substrate 10 on which the laser irradiation is completed to a subsequent process. . In addition, the table assembly TA receives the substrate 10 from the front transfer means 100a and performs a function of supporting the substrate 10 while laser irradiation is performed on the substrate 10. At this time, the center assembly means 100c is provided in the table assembly TA.

According to this embodiment, a conveyor belt is used as the front conveying means 100a, the rear conveying means 100b, and the central conveying means 100c. Applying the in-line type using a conveyor belt in this way, it is possible to improve the yield by enabling a continuous processing. On the other hand, the center transfer means (100c) for positioning the substrate 10 on the table 200 may be coupled to the belt frame (260 of FIG. 17) provided with a roller (240 of FIG. 17) may be driven.

As described above, when the conveyor belt is used as the conveying means 100 for positioning the substrate 10 on the table 200, the table 200 may be formed at the lower side of the central conveying means 100c. May be provided at the location. However, the present invention is not limited thereto, and the position of the table 200 may be changed according to the structure of the transfer means 100.

Meanwhile, in front of the table 200, as illustrated in FIG. 16, a substrate detection sensor 110 that detects a transfer of the substrate 10 may be located. The substrate detection sensor 110 may detect a substrate 10 transferred toward the table 200 and perform a function of accurately positioning the substrate 10 on the table 200 to stop. To this end, after the substrate detection sensor 110 detects the transfer of the substrate 10, a method of stopping the operation of the conveyor belt 100 after a predetermined time (for example, about 1.5 seconds) may be used. Can be.

Meanwhile, a groove (230 of FIG. 17) may be formed on the upper surface of the table 200 to insert the conveyor belt 100c. When the groove 230 is formed in the table 200 as described above, the substrate 10 may be prevented from being separated more than necessary on the table 200 by the conveyor belt 100c positioned above the table 200. , More stable support by the table 200 can be enabled.

On the other hand, according to the present embodiment, it may be provided with an alignment sensor unit (222a, 222b, 222c, hereinafter referred to as 222 in Figure 18) for detecting the alignment of the substrate 10 located on the table 200. The alignment sensor unit 222 detects an alignment state of the substrate 10 located on the table 200. That is, in order to secure the degree of registration between the laser irradiation means 400 and the substrate 10, the alignment state of the substrate 10 is sensed. The sensed alignment state of the substrate 10 is transmitted to the above-described laser irradiation means 400, 400a, 400b, so that the position of the laser irradiation means 400, 400a, 400b depends on the alignment state of the substrate 10. Can be corrected.

In this embodiment, the alignment sensor unit 222, the camera and the lighting means located on the lower side of the table 200 is presented. At this time, the table 200 may be provided with a transparent area (220a, 220b, 220c, referred to below 220 in Figure 17) so that the camera can detect the alignment of the substrate 10. Here, the transparent region 220 does not mean completely transparent, but should be interpreted to include a case where the transparent region 220 is semitransparent enough to optically detect the alignment of the substrate 10. In this embodiment, a structure in which quartz is provided in the transparent region 220 is provided.

On the other hand, the alignment sensor unit 222 is a first sensor 222a for detecting the rear surface of the substrate 10, a second sensor 222b for sensing the side surface of the substrate 10, the substrate ( It may include a third sensor 222c for detecting the rotation state of the 10). In this case, the front and side edges of the substrate 10 are sensed by using the first sensor 222a and the second sensor 222b, and then the X and Y axes of the substrate 10 are detected. The alignment error can be determined, and the alignment error in the rotational direction of the substrate 10 can be determined using the third sensor 222c.

When the alignment state of the substrate 10 is detected, the table 200 and the substrate 10 positioned on the table 200 may be lifted by the table lifter 250 (FIG. 17). The table lifting unit 250 performs a function of raising and lowering the table 200 by a predetermined height. In the state where the substrate 10 is raised by the table lifting unit 250, laser irradiation may be performed on the substrate 10.

The table lifting unit 250 includes: a plurality of support legs 251 arranged to be spaced apart along the edge of the table 200 to support the table 200 and to extend vertically; The cylinder 252 which moves the belt frame 260 up and down can be used. Each support leg 251 may be fastened to the support frame 253 to improve assembly. In addition, various power transmission structures such as a linear actuator (not shown) and a gear train (not shown) may be used.

On the other hand, in order to prevent the movement of the substrate 10 located on the table 200, a negative pressure hole 210 for supplying a negative pressure may be formed in the table 200. When the negative pressure hole 210 is formed in the table 200, and a negative pressure is supplied to the lower surface of the substrate 10 using a pump (not shown), the substrate 10 comes into close contact with the table 200. The alignment state of (10) will not be disturbed.

The structure of the selective emitter forming apparatus of the solar cell according to another aspect of the present invention has been described above. Hereinafter, an embodiment of its operation will be described.

First, when the substrate 10 is supplied on the table 200, the preheating means 300 supplies thermal energy to the substrate 10. This supply of thermal energy may continue until the laser irradiation is completed.

On the other hand, the alignment state of the substrate 10 located on the table 200 is detected by the alignment sensor unit 222, after which the table 200 on which the substrate 10 is placed rises.

On the other hand, the alignment state of the previously detected substrate 10 is transmitted to the laser irradiation means 400 which is spaced apart above the table 200, according to the alignment state of the substrate 10 of the laser irradiation means 400 The position is corrected.

The position-corrected laser irradiation means 400 selectively irradiates a laser to a predetermined position on the substrate 10 to form a second emitter layer (see 16 in FIG. 7).

When the laser irradiation is completed, the table 200 is lowered and returned to its original position, after which the substrate 10 is transferred to a subsequent process line.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

10: Substrate
12: impurities
13a: busbar electrode
13b: finger electrode
14: first emitter layer
16: second emitter layer
16a: busbar floor
16b: finger layer
1000, 1000a, 1000b: transfer assembly
100a, 100b, 100c: transfer means
200: table
300: preheating means
400, 400a, 400b: laser irradiation means

Claims (20)

transfer means for transferring a substrate having an upper surface of a first emitter layer formed by diffusion of n-type impurities;
A table receiving the substrate from the transfer means and supporting the substrate;
Preheating means for preheating the substrate supported on the table;
Laser irradiation means positioned at an upper side of the table and irradiating a laser to a portion of the first emitter layer to form a second emitter layer formed by further diffusing the n-type impurity; And
An alignment sensor unit for sensing the alignment of the substrate located on the table,
The laser irradiation means is characterized in that the position is corrected according to the alignment state of the substrate, selective emitter forming apparatus of a solar cell.
The method of claim 1,
And the preheating means preheats the substrate through the table.
The method of claim 1,
The second emitter layer includes a bus bar layer formed at a position where the bus bar electrode is to be formed, and a finger layer formed at a position where the finger electrode is to be formed.
The laser irradiation means,
First laser irradiation means movable in a first direction to form the busbar layer; And
And a second laser irradiating means movable in a second direction crossing the first direction to form the finger layer.
The method of claim 3,
The table comprises a first table and a second table arranged in series,
The first laser irradiation means is located above the first table to form the bus bar layer,
And the second laser irradiating means is positioned above the second table to form the finger layer.
The method of claim 1,
The second emitter layer includes a bus bar layer formed at a position where the bus bar electrode is to be formed, and a finger layer formed at a position where the finger electrode is to be formed.
The laser irradiation means,
Movable in a first direction to form the busbar layer,
And moveable in a second direction crossing the first direction to form the finger layer.
The method of claim 1,
The conveying means comprises a conveyor belt,
The table is disposed on the lower side of the conveyor belt, Selective emitter forming apparatus of a solar cell.
The method of claim 6,
And a substrate detection sensor positioned at the front of the table to sense the transfer of the substrate and to regulate the operation of the conveyor belt so that the substrate is positioned on the table to stop. Emitter forming device.
delete The method of claim 1,
The alignment sensor unit is located below the table,
The table is characterized in that the alignment sensor unit is provided with a transparent area to detect the alignment state of the substrate, selective emitter forming apparatus of a solar cell.
10. The method of claim 9,
The sensor unit includes:
A first sensor detecting a rear surface of the substrate;
A second sensor for sensing a side surface of the substrate; And
And a third sensor for sensing a rotation state of the substrate.
The method of claim 10,
The first sensor, the second sensor and the third sensor, characterized in that it comprises a lighting means and a camera, selective emitter forming apparatus of a solar cell.
The method of claim 1,
In order to prevent movement of the substrate located on the table, the table is formed with a negative pressure hole for supplying a negative pressure, selective emitter forming apparatus of a solar cell.
positioning a substrate having a first emitter layer formed by diffusion of n-type impurities on a table;
Preheating the substrate located on the table; And
Irradiating a laser to a portion of the first emitter layer to form a second emitter layer formed by further diffusing the n-type impurity,
The laser irradiation step is performed by a laser irradiation means spaced apart from the upper side of the substrate,
Detecting an alignment of a substrate located on the table; And
And correcting the position of the laser irradiation means according to the alignment state of the substrate.
The method of claim 13,
The preheating step, characterized in that performed via the table, selective emitter forming method of a solar cell.
The method of claim 13,
The second emitter layer includes a bus bar layer formed at a position where the bus bar electrode is to be formed, and a finger layer formed at a position where the finger electrode is to be formed.
Irradiating the laser,
First laser irradiation means moving in a first direction to form the busbar layer; And
And a second laser irradiating means moving in a second direction intersecting the first direction to form the finger layer.
The method of claim 13,
The second emitter layer includes a bus bar layer formed at a position where the bus bar electrode is to be formed, and a finger layer formed at a position where the finger electrode is to be formed.
Irradiating the laser,
Selective solar cell, characterized in that carried out by the laser irradiation means which is movable in a first direction to form the bus bar layer, and also movable in a second direction crossing the first direction to form the finger layer. How to form an emitter.
delete The method of claim 13,
Detecting the alignment of the substrate,
Illuminating the substrate; And
And photographing the end of the substrate.
19. The method of claim 18,
Detecting the alignment of the substrate located on the table,
Sensing a front surface of the substrate;
Sensing a side of the substrate; And
And sensing the rotational state of the substrate.
The method of claim 13,
A negative pressure hole is formed in the table,
And supplying a negative pressure to the substrate to fix the substrate placed on the table.

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