KR101325572B1 - Solar cell using printed circuit board - Google Patents

Abstract

The present invention provides a solar cell using a PCB. The solar cell includes a substrate in which a plurality of fixing holes and penetration holes are alternately formed and which is made of insulating material; a plurality of silicon balls which are fixed onto the substrate by being inserted into the fixing holes and generates the photoelectric effect by receiving light through an exposure region on the top surface of the substrate; a plurality of top electrode which are formed on the top surface of the substrate and are connected to the light receiving region of each silicon ball; and a plurality of bottom electrodes which are formed on the bottom surface of the substrate to be connected to the insertion region of each silicon ball and are electrically conductive to the top electrodes.

Description

Solar cell using PCC {SOLAR CELL USING PRINTED CIRCUIT BOARD}

The present invention relates to a solar cell having a structure using a PCB and a silicon ball.

A solar cell is a device that converts light energy into electric energy and generates electricity using two types of semiconductors, a P-type semiconductor and an N-type semiconductor. When light shines on a solar cell, electrons and holes are generated inside. The generated charges move to the P and N poles to generate a potential difference (photovoltaic power) between the P and N poles. At this time, if the load is connected to the solar cell, the current flows, which is called the photoelectric effect.

Silicon solar cells generally used in photovoltaic power generation systems have a structure including a silicon wafer substrate, an upper electrode, a lower electrode, and the like. In a silicon wafer substrate, a P layer and an N layer are bonded to form a P-N junction. In general, an upper portion of the substrate is formed of an N layer and a lower portion of the substrate is formed of a P layer. An upper electrode and an anti-reflection film are formed on the upper surface of the N layer, and a lower electrode is formed on the lower surface of the P layer. When light shines on a solar cell having such a structure, electrons and holes are generated inside, and electrons move toward the N-type semiconductor and holes move toward the P-type semiconductor. Each charged charge moves to the bonded electrode so that a current flows.

According to the solar cell structure as described above, there is a problem that the light receiving area is shrouded by the upper electrode and the light receiving area is reduced. there is a problem. Efforts to improve the photoelectric conversion efficiency include attempts to reduce the line width of the upper electrode to increase the light receiving area, or to reduce the reflection loss by lowering the reflectance of the solar cell. On the other hand, with the above attempts, various researches are being conducted to lower the manufacturing cost of solar cells.

The present invention has been made in view of the above, and to provide a solar cell having a new structure different from the prior art that can increase the light receiving area using a silicon ball and also lower the manufacturing cost by using a PCB substrate structure. will be.

In order to achieve the above object, the present invention provides a substrate made of an insulating material having a plurality of fixing holes and conductive holes alternately formed therein, and a portion of which is inserted into the fixing hole to be fixed to the substrate and exposed to an upper portion of the substrate. A plurality of silicon balls that receive light to generate a photoelectric effect, a plurality of upper electrodes formed on an upper surface of the substrate and connected to a light receiving area of each silicon ball, and connected to an insertion area of each silicon ball Disclosed is a solar cell using a PCB including a plurality of lower electrodes formed on a rear surface and electrically connected to the upper electrode through the through hole.

The silicon ball may include P-type or N-type silicon, and a diffusion layer forming a P-N junction may be formed on a surface of the light-receiving region of the silicon ball.

The surface of the silicon ball may have a texture, and a coating layer coated with an antireflective material may be formed on the surface of the silicon ball.

The upper electrode is formed to define the fixing hole and is connected to the light receiving region of the silicon ball, a first extension extending in a first direction from the ball connection portion, and formed at the end of the first extension portion And an upper conductive part formed to define the conductive hole.

The lower electrode is filled in the fixing hole and connected to the insertion region of the silicon ball, a second extension extending from the charging portion in a second direction opposite to the first direction, and the second It may have a structure including a lower conductive portion formed at the end of the extension portion and formed to define the conductive hole.

An anti-reflection film formed by coating an anti-reflection material may be additionally formed on the upper surface of the substrate, and a glass plate having a CNT coating layer may be installed on the upper surface of the anti-reflection film.

According to the present invention having the above-described configuration, since the light is absorbed using the silicon ball, the light receiving area can be increased compared to the conventional flat panel solar cell, and since the upper electrode is located under the silicon ball, the light is emitted by the upper electrode. Fixed the problem of obscurity.

In addition, it is possible to manufacture a solar cell using a circuit pattern manufacturing technique of the PCB substrate, which can simplify the manufacturing process and reduce the manufacturing cost.

In addition, the reflection loss can be significantly reduced through the surface texture structure of the silicon ball, the antireflective coating layer of the silicon ball, and the CNT coating layer structure of the glass plate.

In addition, solar cells having various areas can be manufactured according to the area of the substrate and the number of silicon balls. Since there is no need to use a ribbon for connecting cells, the power loss problem caused by the lead resistance of the ribbon can be solved. .

1 is a cross-sectional view of a solar cell using a PCB according to an embodiment of the present invention.
2 is a plan view of the substrate shown in FIG.
3 is a rear view of the substrate shown in FIG.
4 is an enlarged cross-sectional view of the silicon ball shown in FIG.
5 is a plan view of a substrate illustrating an example of an upper electrode array;
6 is a rear view of the substrate, showing an example of the lower electrode array;

Hereinafter, a solar cell using a PCB according to the present invention will be described in more detail with reference to the accompanying drawings.

1 is a cross-sectional view of a solar cell using a PCB according to an embodiment of the present invention. 2 is a plan view of the substrate shown in FIG. 1, and FIG. 3 is a rear view of the substrate shown in FIG. 1.

1 to 3, a solar cell of the present invention includes a substrate 110 made of an insulating material, a plurality of silicon balls 120 installed on the substrate 110, and a plurality of substrates formed on an upper surface of the substrate 110. An upper electrode 130 and a plurality of lower electrodes 140 formed on the bottom surface of the substrate 110.

The substrate 110 is an insulating material, and a substrate used for a general printed circuit board (PCB) is used. The substrate 110 may be formed of a material such as an epoxy resin, a phenol resin, or a polyimide.

The plurality of fixing holes 111 and the conductive holes 112 are alternately formed in the substrate 110. The fixing hole 111 and the conductive hole 112 are alternately formed along a specific direction. The fixing hole 111 provides a space in which the silicon ball 120 is seated, and the through hole 112 provides a space for conducting the upper electrode 130 and the lower electrode 140.

A plurality of silicon balls 120 is inserted into each of the fixing holes 111 and fixed to the substrate 110, and have a diameter larger than the diameter of the fixing holes 111. The silicon ball 120 receives a light through a portion exposed to the upper portion of the substrate 110 (hereinafter, referred to as an “exposure region”) to generate a photoelectric effect. The configuration of the silicon ball 120 will be described later in detail.

The plurality of upper electrodes 130 are formed on the upper surface of the substrate 110 and are connected to the light receiving regions (ie, exposed regions) of the silicon balls 120. Referring to FIG. 2, the upper electrode 130 may have a structure including a ball connecting portion 131, a first extension portion 132, and an upper conductive portion 133.

The ball connector 131 is formed to define the fixing hole 111 and is connected to the light receiving region of the silicon ball 120. The ball connecting portion 131 may be formed in a ring shape and is in contact with and electrically connected to the light receiving region of the silicon ball 120.

The first extension part 132 has a structure extending from the ball connection part 131 along the first direction (the right direction in FIG. 2). The first extension part 132 extends from the ball connection part 131 to the through hole 112 at a position away from the ball connection part 131 in the first direction.

The upper conductive portion 133 is formed at an end portion of the first extension portion 132 and is formed to define the conductive hole 112. The upper conductive portion 133 may be formed in a ring shape like the ball connecting portion 131.

The plurality of lower electrodes 140 are formed on the rear surface of the substrate 110 and are connected to portions inserted into the fixing holes 111 of the silicon balls 120 (hereinafter, referred to as insertion regions). The lower electrode 140 is electrically connected to the upper electrode 130 through the through hole 112 to allow electrical connection (serial connection) of each silicon ball 120.

Referring to FIG. 3, the lower electrode 140 includes a charging unit 141, a second extension part 142, and a lower conductive part 143.

The charging unit 141 is filled in the fixing hole 111 to be connected to the insertion region of the silicon ball 120. The charging unit 141 is formed by filling a conductive material in the fixing hole 111. An insulating material 115 may be formed in the fixing hole 111 to insulate the ball connecting portion 131 from the charging portion 141.

The second extension part 142 has a structure extending from the charging part 141 along the second direction (the direction opposite to the first direction, the left direction in FIG. 3), and is located in a second direction away from the charging part 141. It extends to the through hole 112.

The lower conductive portion 143 is formed at the end of the second extension portion 142 and is formed to define the conductive hole 112. The lower conductive portion 143 may be formed in a ring shape like the upper conductive portion 133 and is connected to the upper conductive portion 133 of the upper electrode 130 through the plating layer 115 of the inner wall of the conductive hole 112. .

The upper electrode 130 and the lower electrode 140 may be formed of a conductive material such as copper or silver, and may be formed by the same method as a general circuit pattern forming method of a printed circuit board (PCB). Through the above electrode configuration, the light receiving region of the silicon ball 120 is electrically connected to the lower electrode 140 at a position separated in the first direction through the upper electrode 130, and the insertion region of the silicon ball 120 is The upper electrode 130 is electrically connected to the second electrode 140 in the second direction through the lower electrode 140.

The upper surface of the substrate 110 is coated with an anti-reflection material (for example, fluorine resin, nanoparticles, SiO ₂ , TiO _2, etc.) to form an anti-reflection film 150, and the lower surface of the substrate 110 is made of an insulating material An overcoat layer 180 is formed to protect the lower electrode 140.

On the upper surface of the anti-reflection film 150, a light transmissive plate 160 made of a light transmissive material (eg, glass) capable of passing light is disposed to protect the upper electrode 130. A CNT coating layer 170 containing a carbon nanotube material may be formed on an upper surface of the light transmissive plate 160. The CNT coating layer 170 reduces the reflectance so that the maximum amount of light is transmitted to the silicon ball 120.

According to the structure of the solar cell described above, since the light is absorbed by using the silicon ball 120, the light receiving area can be increased compared to the conventional flat solar cell, and the upper electrode 130 is located under the silicon ball. There is no room for the problem that light is blocked by the upper electrode 130. In addition, it is possible to manufacture solar cells using circuit pattern fabrication techniques of PCB substrates, which simplifies the manufacturing process and reduces manufacturing costs.

4 is an enlarged cross-sectional view of the silicon ball illustrated in FIG. 1.

The silicon ball 120 includes P-type or N-type silicon, and a diffusion layer 121 forming a P-N junction is formed on the light-receiving region surface of the silicon ball 120. The silicon ball 120 may further include a P-type or N-type dopant.

4 illustrates a structure in which the silicon ball 120 is formed of P-type silicon and an N-type diffusion layer 121 is formed on the surface of the silicon ball 120. In this case, the N-type diffusion layer 121 may be formed by performing a doping process by diffusing POCl ₃ , H ₃ PO ₄ , and the like containing a Group 5 element into the silicon ball 120 made of P-type silicon at a high temperature. It is also possible to perform the doping process with the silicon ball 120 attached to the substrate 110. In this case, a POCl ₃ or H ₃ PO ₄ layer is additionally formed on the substrate 110.

Meanwhile, the silicon ball 120 as shown in FIG. 4 may not only have a structure formed of silicon, but also a structure in which silicon is coated on the insulating ball.

The ball connector 131 of the upper electrode 130 is in contact with the diffusion layer 121 and the N pole, and the charging unit 141 of the lower electrode 140 is connected to the P-pole region of the silicon ball 120. When light shines on the silicon ball 120, electrons and holes are generated in the silicon ball 120. The electrons move toward the N-type diffusion layer 121 to move to the upper electrode 130, and the holes are lower electrode 140. Current flows.

The surface of the silicon ball 120 may have a texture shape 122 to reduce the reflectance, and the coating layer 123 coated with an antireflective material may be further formed on the surface of the silicon ball 120. Can be. As described above, not only the texture surface is formed on the silicon ball 120 and the anti-reflective coating layer 123 is formed on the surface thereof, but also the CNT coating layer 170 is formed on the light transmissive plate 160 to significantly reduce the reflection loss.

5 is a plan view of a substrate illustrating an example of an upper electrode array, and FIG. 6 is a rear view of a substrate illustrating an example of an lower electrode array.

5 and 6, the upper electrode 130 is arranged to form a plurality of rows, and the lower electrode 140 is arranged to correspond to the arrangement of the upper electrode 130. In addition to such a shape, solar cells having various structures may be manufactured according to the pattern shape and arrangement of the upper electrode.

In particular, in the case of the conventional silicon solar cell manufactured a solar cell module by connecting a plurality of cells, according to the present invention, such a concept is not necessary and various areas according to the area of the substrate 110 and the number of silicon balls 120 Can manufacture solar cells. It also eliminates the need to use ribbon to connect cells, eliminating the power loss problem caused by ribbon lead resistance.

In the above described with reference to the accompanying drawings, a solar cell using a PCB according to the present invention, the present invention is not limited to the embodiments and drawings disclosed herein, those skilled in the art within the scope of the technical idea of the present invention Various modifications can be made by way of example.

Claims (9)

A substrate made of an insulating material in which a plurality of fixing holes and conductive holes are alternately penetrated;
A plurality of silicon balls, a portion of which is inserted into the fixing hole and fixed to the substrate and which receives a light through an exposed area exposed to an upper portion of the substrate to generate a photoelectric effect;
A plurality of upper electrodes formed on an upper surface of the substrate and connected to the light receiving regions of the silicon balls; And
And a plurality of lower electrodes formed on a rear surface of the substrate so as to be connected to the insertion regions of the silicon balls, and including a plurality of lower electrodes connected to the upper electrodes through the through holes. The method of claim 1,
The silicon ball includes a P-type or N-type silicon, the solar cell using a PCB, characterized in that the diffusion layer forming a PN junction is formed on the surface of the light receiving region of the silicon ball. The method of claim 1,
Surface of the silicon ball is a solar cell using a PCB, characterized in that having a texture (texture) shape. The method of claim 1,
Solar cell using a PCB, characterized in that the coating layer coated with an anti-reflection material is formed on the surface of the silicon ball. The method of claim 1, wherein the upper electrode,
A ball connection part formed to define the fixing hole and connected to the light receiving area of the silicon ball;
A first extension part extending in a first direction from the ball connection part; And
A solar cell using a PCB, which is formed at an end portion of the first extension portion and includes an upper conductive portion formed to define the conductive hole. The method of claim 5, wherein the lower electrode,
A charging unit filled in the fixing hole and connected to an insertion region of the silicon ball;
A second extension part extending from the charging part in a second direction opposite to the first direction; And
A solar cell using a PCB, which is formed at an end of the second extension portion and includes a lower conductive portion formed to define the conductive hole. The method according to claim 6,
The solar cell using a PCB, characterized in that an insulating material is formed in the fixing hole to insulate between the ball connecting portion and the charging portion. The method of claim 1,
The solar cell using a PCB, characterized in that it further comprises an anti-reflection film formed by coating an anti-reflection material on the upper surface of the substrate. 9. The method of claim 8,
A glass plate disposed on an upper surface of the anti-reflection film; And
The solar cell using a PCB formed on the upper surface of the glass plate, further comprising a CNT coating layer containing a carbon nanotube material.

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