KR20110138435A - A small sized solar cell module and the method thereof - Google Patents

Abstract

PURPOSE: A small solar cell module and a manufacturing method thereof are provided to drastically reduce melting or coagulation of a solar cell cutting surface, thereby drastically increasing the efficiency of a small solar cell. CONSTITUTION: A solar cell is half-cut by laser scribing. The half-cut solar cell is full-cut by a brake work. (+) terminal and (-) terminal are formed on one side of the frontal side of a solar cell electrode substrate. A unit solar cell includes the top of (-) part and the bottom of (+) part. (+) bus bar and (-) bus bar are vertically formed on one side of a unit solar cell.

Description

Small solar cell module and its manufacturing method {a small sized solar cell module and the method

The present invention relates to a small solar cell module manufacturing method and a small solar cell module according to the manufacturing method, and more specifically, using a flexible printed circuit board as a solar cell connection means to minimize the gap between the cells, the manufacturing process It is possible to improve the workability in the system, and after cutting the half cell with the ultra-precision laser scribing technology, the full cell is cut by the braking operation, and the solar cell is arranged side by side on the substrate to make the small solar cell module simple. The present invention relates to a small solar cell module that can be easily manufactured and has excellent durability and very low defect rate.

In general, a solar cell is a device that converts solar light into electrical energy by using a semiconductor property, and recently, a small, thin, and light that can be used as an auxiliary power source for a portable information device such as a mobile phone or a PDA (Personal Digital Assistance).

High power solar cell modules are being studied.

As shown in FIG. 1, in a typical solar cell, a cell is composed of a semiconductor that absorbs sunlight to generate a charge, an upper electrode positioned on the side of the light receiving surface on which light is incident, and a lower electrode positioned on an opposite side of the upper electrode. Each cell in the solar cell module is connected by a metal ribbon (metal connector).

The entire connected solar cell is then filled with transparent resin and protected from the external environment by the lower sheet and the transparent upper sheet.

In this case, since most individual cells have an output voltage of 0.6 or less, several cells must be connected in series in order to obtain a high voltage actually required. This allows each metal ribbon to connect the top electrode of one cell and the bottom electrode of a neighboring cell.

It is arranged in the form.

However, in the structure using the metal ribbon, since the metal ribbon must pass between the cells, at least 1 mm gap between the cells is indispensable and there is a limit in miniaturization of the module. In addition, the metal ribbon is easily deformed even with a small force, which lowers workability in the process after cell connection, and has disadvantages in automation.

Regarding the cell connection structure of the solar cell module described above, U.S. Patent No. 4,019,924 describes a laminate in which a plurality of conductive layers are patterned between a pair of insulating sheets, and a tab that can be bent by cutting a portion of the laminate and making it bendable. The structure of connecting the upper electrode of the cell with the exposed portion of the conductive layer in the tab is disclosed.

U.S. Pat.Nos. 4,131,755 and 4,227,298 also describe laminates consisting of a conductive layer and a dielectric layer, and forming acute taps through a portion of the laminate and extending the tabs over the top electrode of the cell to connect the conductive layer and the top electrode. The structure is disclosed.

However, the structures disclosed by the above patents involve a process of cutting or drilling a laminate in addition to the soldering work for cell connection, which complicates the manufacturing process of the module, and has a large area occupied by non-cell members in the module, which is disadvantageous for miniaturization of the module. .

In addition, due to the formation of cutouts and holes in the laminate, it is not structurally stable. For this reason, workability after the cell connection work is deteriorated, and there is a disadvantage in automation.

The solar cell module is mainly produced by large enterprises as a large-scale power plant or an integrated solar cell module. However, small solar modules, that is, solar modules for wireless IT devices, are mostly manufactured in China. Conventional small Chinese solar cell modules have the disadvantages of poor design and very low cell efficiency due to the limitation of laser scribing technology and lamination using epoxy.

In addition, the problem of the cell connection method seen in the prior art is exposed as it is, and due to this problem, the conventional solar cell is not only in a very difficult environment to integrate with existing IT devices, but also in a situation where the efficiency is significantly reduced. There is an urgent need for a compact solar cell module with improved efficiency and manufacturing method. In addition, as shown in FIG. 1, in order to connect a plurality of conventional solar cells in series or in parallel, a plurality of solar cells are cut by a worker using a connection means such as a conductive metal foil. Soldering (soldering) one by one while matching.

In the case of manufacturing a solar cell module in the manner as described above, a solar cell that requires a precise design because it takes a lot of time to produce, a high occurrence rate of defects, and it is difficult to constantly match the gap between the solar cell and other cells when soldering. There was a disadvantage that the production of the module is difficult.

In addition, in the case of a small solar cell module using EVA, PET or tempered glass, it is very difficult to manufacture by using a series connection method of the up and down cross form, which has a fatal disadvantage that it takes a long time and increases the defective rate.

In order to solve the above problems,

Half-cutting the cell with laser scribing,

Full cutting of half cut solar cell by brake work,

A process of manufacturing a solar cell electrode substrate having a positive terminal and a negative terminal formed on one side of the front surface, and a positive terminal and a negative terminal connected in series on the rear surface thereof;

(+) Bus bar of the full-cut small solar cell is bonded to the solar cell electrode substrate (+) terminal with a solder cream, and then connected to (-) bus bar of the small solar cell and (- ) The process of soldering to the terminal with connecting elements,

The present invention provides a small solar cell manufacturing method and a small solar cell module including laminating after the final process.

The small solar cell module manufacturing method of the present invention can provide a solar cell module that is smaller in size than a conventional solar cell module and can be applied to a product of a durable IT device.

The half cutting scribing / breaking method of the present invention significantly reduces melting and solidification due to laser heat on the solar cell cutting surface, which is a disadvantage of the laser pull cutting or brake method used in the conventional small solar cell manufacturing method. There is an effect that can significantly increase the efficiency of the small solar cell.

In addition, the present invention has the effect of minimizing the efficiency reduction of the solar cell even in the manufacture of a small solar cell in the one side of the cell range of 4mm ~ 40mm.

In addition, the solar cell substrate according to the present invention is capable of manufacturing a large capacity of a small solar cell, and exhibits a functional effect that can be achieved by an automatic system rather than by hand.

In addition, the small solar cell module manufacturing method according to the solar cell electrode substrate according to the present invention is simplified in the work and remarkably shortened working time than the conventional method, the inconvenience of the work is eliminated, and does not require the skill of the work Of course, there is an effect that significantly reduces the defective rate of the solar cell.

In addition, since the electrode substrate according to the present invention does not require wiring, an unnecessary process of manufacturing a solar cell module is eliminated.

1 is a method of manufacturing a small solar cell module according to the present invention.
Figure 2 is a conventional small cell module manufacturing method.
3 is one example of a method of manufacturing a small solar cell module according to the present invention.

As shown in FIG. 1, the small solar cell module manufacturing process of the present invention uses the ultra-precision laser scribing technique to half-cut the cell by optimally adjusting the processing conditions of the laser, that is, the scan speed, pulse period, and oscillation time. , The cell is completely cut by the braking operation, and manufactured into a unit cell (meaning the cutting cell of FIG. 2). A small unit solar cell is mounted on a solar cell substrate (PCB substrate) having a special technical feature of the present invention. A method of manufacturing a small solar cell module and a small solar cell module by arranging the solar cells on the solar cell substrate as described above and then soldering and then laminating using EVA, PET, or tempered glass. to provide.

The present invention has a special technical feature on the solar cell substrate (PCB substrate) as described above. Conventional solar cell module PCB substrate is difficult to assemble the solar cell by using a method of connecting the solar cells using the wiring, not only takes a long time but also a high failure rate, the present invention requires wiring The present invention provides a method of designing a solar cell substrate, which significantly reduces manufacturing time and defect rate of a small solar cell module, and a small solar cell module.

Hereinafter, a small solar cell module and a method of manufacturing the same according to the present invention will be described in detail.

The small solar cell module of the present invention starts by performing a process of cutting a mother solar cell (typically 125 mm x 125 mm in width and length) into unit cells using a scribing technique. It manufactures by the method of half cutting (half cutting) a unit cell. One of the technical features of the present invention is to half-cut the solar cell.

In general, the method of cutting any material can be carried out by physical and chemical means. Various cutting means, such as a method of applying an external force, a method of chemically cutting, or a method of using a laser, may be used according to the physical characteristics such as the type or strength or hardness of the material to be cut.

Therefore, the present invention is carried out by half-cutting the cutting cross-sectional area of the solar cell using any of the above methods. Recently, a method of cutting a material using a laser is known in detail among the cutting methods. In the present invention, cutting by scribing (cutting) using a laser is efficient and preferable.

As a method of irradiating a workpiece with a laser beam to remove a small amount, scribing, trimming, mask making and mask repair, engraving, etc., in the present invention, Ice cutting is efficient. Scribing generally refers to a method of making a groove using a diamond scriber when cutting a semiconductor wafer and then breaking the wafer by applying stress to the back side of the wafer. Although many diamond scribers are used in the scribing process, scribing using a laser is also widely used. Therefore, the present invention may use a scriber such as diamond, but scribing using a laser is more preferable.

Diamond scribing is efficient because laser scribing has the disadvantage of having a large cutting width, defects at the tip of the material, and minute cracks that affect the performance of the solar cell device. This is because laser scribing can sharpen the end shape of the cutting groove very much and concentrate the stress on the very sharply formed groove when stress is applied so that the cutting of the solar cell is very easy and the cutting surface is clean. Moreover, in the related art, full cutting for completely cutting a solar cell through laser scribing has been performed, but such a full cutting has a disadvantage of lowering the efficiency of solar cell engraving. In addition, the full cutting using this laser was mainly suitable for manufacturing a large-sized solar cell. In general, when cutting a solar cell using a laser, a small solar cell is manufactured because the cutting edge of the solar cell is melted and solidified again by laser heat, thereby causing a problem of significantly deteriorating the function of the solar cell. Because it was very unsuitable.

In particular, when a small solar cell is completely cut through laser scribing, the cutting surface is melted by the heat of the laser and cooled again, which significantly reduces the function of the solar cell. Therefore, it cannot be used as a small solar cell that can be used for IT equipment. .

Moreover, considering the size of the small and horizontal cell is 4mm to 40mm, it can be said that the function of the small solar cell is completely deteriorated when the laser is used for full cutting. Therefore, through such a conventional scribing it is impossible to manufacture an intact solar cell module.

On the other hand, the present invention can manufacture a complete unit solar cell through a process of half-cutting a solar cell using laser scribing and then completely cutting it in a breaking process. Such half-cutting scribing / breaking process of the present invention can be said to be one of the technical breakthroughs in the manufacture of small solar cells. Laser half-cutting of the solar cell in the present invention does not mean that it cuts half of the cross-section of the cell literally, but a preliminary to make a complete cutting in the next brake process by making a cutting groove in the portion to be cut of the solar cell. Means fair. Thus, the cut cross section in half cutting by scribing means cutting more than 0% and less than 100% of the total cut cross section (cutting cross section of the cell) by scribing, but preferably 15 of the total cut cross section. It is recommended to cut ~ 85%. Even more preferably it is better to cut 25 to 45% of the cut cross section. Within this range, a clean solar cell cross section can be obtained during the next braking operation, resulting in a compact unit cell with full efficiency.

Laser scribing generally uses pulsed lasers and must be drilled at regular intervals rather than overlapping pulses. The repetition rate of energy per pulse is selected in consideration of the shape of the pulse. Although the type of laser varies depending on the material, 355 nm, 532 nm, and 1064 nm high power pulse lasers are widely used.

Therefore, the present invention is to use the ultra-precision laser scribing technology to half-cut the solar cell by optimally adjusting the laser processing conditions, ie scan speed, pulse period, oscillation time, etc., for the solar cell material. Such processing conditions can be obviously performed by those skilled in the art. That is, according to the linear width and length of the electrode pattern, the processing conditions such as the energy intensity and the scanning speed of the laser beam can be controlled together with the characteristics of the substrate to be processed such as thermal conductivity. Therefore, depending on the line width and length, the laser head is finely controlled on the X-axis or Y-axis, or the initial output is monitored at the initial stage every such X-axis Y-axis movement. By controlling the energy, pulse, etc., the energy intensity can be adjusted to half-cut the solar cell.

After the scribing, the brake process means that the solar cell is completely cut by applying stress to the half-cut solar cell as described above. That is, the half-cut solar cell mentioned above is subjected to a process of cutting the solar cell by braking. The brake process is generally a process of placing a brake bar on a solar cell on which a minute crack-shaped cutting line is formed and applying a momentary force to the solar cell. In a typical brake process, instantaneous and strong force is transmitted to the solar cell in which the crack is formed, and defects of the cutting surface are increased due to minute pieces during cutting, and the performance of the solar cell is reduced. Particularly, in the case of the conventional small solar cell, a very small solar cell is manufactured, and thus the defect rate is higher and the performance of the solar cell is significantly reduced.

However, by performing the half cutting in the scribing process and then completely cutting in the brake process as described above in the present invention, it is possible to significantly lower the defective rate and increase the performance, which is the aforementioned problem. As such, it is a feature of the present invention that the half cutting scribing / breaking process can dramatically increase the performance of a small solar cell.

Another technical feature of the present invention lies in the specificity of the substrate which drastically improves the problem of the conventional solar cell substrate, thereby eliminating the inconvenience of assembly and also reducing the defective rate.

Conventional solar cell substrates use a PCB (Printed Circuit Board) plate using a variety of materials. As shown in FIG. 2, the conventional solar cell PCB board has a (-) bus bar at the center of the cell after aligning the solar cells in which (-) and (+) devices are formed on the cell support substrate in a row. The solar cell module was completed by zigzag-connecting "connectors" commonly referred to as ribbons with the positive and negative bus bars. However, when manufactured by the conventional method in a small solar cell module, assembling the unit cell, ie, aligning it on the substrate, is not only a difficult process, but also connecting the unit cell once aligned and fixed to the connection element. In addition, the manufacturing process takes a long time due to the difficult process, as well as a large increase in the defective rate.

However, in the solar cell substrate of the present invention, (+) terminal and (-) terminal are formed on one side of the front surface, and the (+) terminal and (-) terminal in series on the back surface. The unit cell is mounted side by side with the same electrode terminal facing the same direction on one side of the front side of the electrode substrate, but the positive bus bar of the solar cell is The technical feature is that it is soldered to the (+) terminal and the (-) bus bar of the solar cell is configured to be soldered to the (-) terminal on the front of the substrate.

As the solar cell substrate structure is taken, solder cream is applied to the same electrode terminal (specifically, the (+) terminal), and the (+) bus bar of the unit cell is mounted side by side so that it is naturally bonded to the (+) terminal. do. In addition, the (-) bus bar of the unit cells is oriented side by side in the opposite direction of the (+) bus bar. Therefore, the connection between the (-) terminal of the solar cell board and the (+) bus bar of the unit solar cell is simple. Soldering not only makes the production considerably easier, but also enables large-scale production and standardizes the process, resulting in an automated process.

In particular, in the case of small solar cells, such a large-scale manufacturing process was not possible in the past, but the process according to the present invention can be applied to small solar cells, thereby achieving the effect of shortening the manufacturing time and remarkably reducing the defective rate.

Referring to the solar cell substrate of the present invention in more detail, (-) and (+) terminals are formed in a zigzag form on one side of the front surface of the solar cell substrate. Zigzag type means that the (-) terminal and the (+) terminal are sequentially formed at regular intervals.

On the back surface of the solar cell substrate, the negative terminal and the positive terminal are connected in series. (-) Terminal is connected to (+) terminal and (+) terminal is connected to (-) terminal, but (-) terminal and (+) terminal, which are the first and last terminals, are not connected It means that it is formed in a good position to output power.

In addition, unit cells are arranged side by side on the (-) and (+) terminals which are formed in a zigzag pattern with a predetermined pattern on the front surface of the electrode substrate. In this case, the unit cell is characterized in that the negative bus bar and the positive bus bar are formed on one side. The negative bus bar and the positive bus bar of the unit cell can be formed on one side because the half cutting scribing / breaking process is used as described above. Therefore, a conventional unit solar cell is formed with a negative bus bar and a positive bus bar at the center of the unit cell, and there is a remarkable difference from connecting the ribbon with a connecting element.

Of course, in the past, various PCB substrates are created and have various names to be utilized. For example, there is a flexible printed circuit board (FPCB) of Patent No. 10-0416139, which not only complicates the manufacturing of the substrate but also takes the method of soldering the conductive film exposed through the front opening, which adds to the cumbersome process. I just let you.

However, unlike the conventional method, the solar cell electrode substrate of the present invention applies solder cream to the (+) terminal of the electrode substrate as described above, so that the (+) bus bar of the unit cells is parallel to the (+) terminal of the electrode substrate. It is possible to join. This effect enables the innovation of the solar cell deployment interval. In addition, the joints can also be exactly matched at the same position, so the joining effect is significantly increased. As described above, the (-) bus bars of the unit cells that are aligned not only point in the same direction but also form the same spatial coordinates, so that the (-) bus bar of the solar cell and the (-) formed at a predetermined position on the electrode substrate The terminal can be soldered simply by using a connection element. As shown in Fig. 3, the connecting element can be freely used in any form such as a Z-shaped S-shaped one-shaped shape.

As such, when a plurality of unit solar cells are disposed on the solar cell substrate and soldered, the lamination process is then performed. Laminating is a process of forming a transparent barrier film in order to prevent oxidation and breakage by air of the solar cell. In general, the laminating material may be a polymer and glass such as polyethylene, polypropylene and the like, preferably EVA, PET or tempered glass. Such a laminating step can be performed in a usual laminating step, of course.

Even after the laminating process or before the process, when the electrode is attached to the first and last terminals of the (-) and (+) terminals of the solar cell substrate of the present invention and used as a power source, a small solar cell module is completed.

Claims (4)

In the small cell module manufacturing method,
Half-cutting the cell with laser scribing,
Full cutting of half cut solar cell by brake work,
A process of manufacturing a solar cell electrode substrate having a positive terminal and a negative terminal formed on one side of the front surface, and a positive terminal and a negative terminal connected in series on the rear surface thereof;
(+) Bus bar of the fully-cut unit cell is bonded to the solar cell electrode substrate (+) terminal with a solder cream, and then connected (-) bus bar of the unit cell and (-) ) The process of soldering to the terminal with connecting elements,
A method of manufacturing a small solar cell module including laminating after the final process.
The method of claim 1,
Half cutting scribing / breaking is carried out to form (+) bus bar and (-) bus bar on one side of the unit cell,
Laminating method of manufacturing a small solar cell module, characterized in that the lamination with EVA, PET or tempered glass.
A unit cell having an upper surface of the (-) part and a lower surface of the (+) part;
A solar cell electrode substrate having a positive terminal and a negative terminal on one side of the front surface, and a positive and negative terminal connected to the rear surface thereof;
The solar cells are mounted on one side of the front side of the solar cell substrate in a state where the cutting cells of the unit cells are aligned side by side. A small solar cell module bonded and laminated with a (-) bus bar of the unit solar cell soldered to the negative terminal on the front surface of the cell electrode substrate with connecting elements.
The method of claim 3,
On one side of the unit cell, (+) bus bar and (-) bus bar is formed up and down,
Compact solar cell module, which is laminated with EVA, PET or tempered glass.

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