JP4275121B2 - Manufacturing method of glass substrate for solar cell - Google Patents

Description

The present invention relates to a method for producing a glass substrate for a solar cell.

  A conventional solar cell in which a power generation film is formed on a substrate such as amorphous silicon (hereinafter referred to as a-Si), microcrystalline silicon, or thin film polycrystalline silicon is a solar cell module between a thick cover glass 4 and a back cover sheet 5. 2 is sandwiched. The solar cell module 2 is formed by sequentially laminating a transparent electrode layer, a power generation layer such as a-Si, and a metal electrode layer on a thin glass substrate having a thickness of about 1 mm.

  In the laminating process, as shown in FIG. 9, a plurality of, for example, four solar cell modules 2 are covered with a cover glass 4 on the light incident surface side, and the solar cell modules are electrically collected and connected in series and parallel as appropriate. The back cover sheet 5 is overlaid on the back side, and for example, a heat-adhesive EVA sheet 3 is placed between the cover glass 4 and the battery module 2 and between the back cover sheet 5 and the battery module 2, respectively. Insert and heat-press it. A solar cell having a cover glass size prepared in advance as a predetermined dimension is obtained.

  By the way, since the conventional solar cell module 2 is set in advance assuming a size close to the final product, the size of the cover glass 4 is fixed to approximately an integral multiple of the size of the battery module 2. For this reason, a size out of the standard is handled as a custom-made product, and there is a problem in terms of cost and delivery time, so a mass production factory cannot actually manufacture a size out of the standard.

  Therefore, a solar cell functional layer is directly laminated on a cover glass of any size, and a back cover sheet is laminated by lamination to form a panel, and the panel is cut and divided into desired sizes to meet various customer requirements. It is possible to do so.

  However, if an attempt is made to cut the cover glass, cracks will develop around it and it will be divided into small small pieces that cannot be cut sharply along the planned cutting line. This is due to the fact that tempered glass is used so that sufficient strength can be obtained even with a thin plate thickness to reduce the weight of the cover glass. This is because the high residual stress is eliminated by the notch, the apparent tensile strength is lowered, and a large number of cracks develop around. For this reason, there is a problem that it is practically impossible to divide the glass into a desired size after the glass is used for both the solar cell function glass substrate and the protective cover glass in the accepting state.

  In addition, mass production plants need to have production lines that correspond to each product size, and in order to distribute products of different sizes to the same production line, there are various restrictions such as handling devices and positioning devices, so it is actually a standard. Other different size products cannot be manufactured on the same line. For this reason, there exists a problem that it cannot respond to a customer's various requests and requests.

The present invention has been made to solve the above-described problems, and is most suitable between a tempered glass and a green glass for facilitating the division of a solar cell panel capable of accommodating various sizes. An object of the present invention is to provide a method for manufacturing a glass substrate for a solar cell, which can be divided into high strength levels and can be divided.

  Glass is a material that is strong against compression but weak against tension. Further, since a surface defect called Griffith Flow exists on the surface layer of the glass, the surface layer tends to be a starting point of the breakage when the glass is broken. Therefore, in the tempered glass, the apparent tensile strength is improved by artificially applying a compressive stress to the surface layer.

  There are three types of tempered glass: physical (thermal) tempered glass, chemically tempered glass, and laminated tempered glass. For example, physically tempered glass is tempered so as to impart a high compressive residual stress to the surface layer portion by a heat treatment that is rapidly cooled to a temperature near the softening point and then has a strength two to three times that of green glass. When notches are generated on the surface of such tempered glass, the residual stress on the surface layer is eliminated by the notches, the apparent tensile strength decreases, and a large number of cracks develop around the surface. Can't cut. Therefore, as a result of intensive studies on measures for cutting tempered glass, the present inventors have completed the present invention.

The method for manufacturing a solar cell glass substrate according to the present invention has a role as a cover for protecting the power generation functional layer, and the power generation functional layer is directly laminated, and is cut after the power generation functional layer is laminated. A method of manufacturing a glass substrate for a solar cell that is divided into a desired product size, using green glass as a starting material, and before laminating the power generation functional layer, the green glass is brought to a temperature range of 500 to 550 ° C. By heating and holding for a predetermined time and then rapidly cooling, the strength is set in a range from 1.20 times to 1.70 times the strength of soda-lime glass in a state of being unmolded.

Here, “green plate glass” refers to colorless and transparent soda-lime glass (ordinary plate glass) in a state in which no special treatment is performed after die cutting. The strength of the green glass is generally about 5000 to 10000 Pa (5 to 10 kg / mm ² ).

  Here, “tempered glass” refers to physical (heat) tempered glass. The strength of physically strengthened glass is about 2 to 3 times the strength of green glass.

“Strain point” refers to the temperature at which the viscosity is 4 × 10 ¹⁴ poise (log η = 14.5). At this strain point temperature, viscous flow cannot practically occur, so when the temperature falls below the strain point, strain cannot be removed from the glass.

The “softening point” refers to a temperature when the viscosity is 4.5 × 10 ⁷ poise (log η = 7.65). When heated to the softening point temperature, a glass yarn having a diameter of 0.55 to 0.75 mm and a length of 230 mm is stretched at a rate of 1 mm / min.

  A correlation characteristic curve between viscosity and temperature is determined for each glass composition. When the strain point and the softening point are examined using the correlation characteristic curve of soda-lime glass, the strain point is about 480 to 510 ° C and the softening point is about 720 to 735 ° C.

  In the present invention, when using raw glass as received, it is necessary to make it thick due to insufficient strength, and because it is heavy and unsuitable as a glass substrate for solar cells, A semi-tempered glass that is heated and held in a temperature range of 550 ° C. for a predetermined time, and then rapidly cooled to raise its strength from 1.20 times to 1.70 times the strength of soda-lime glass in an unmolded state. It is thinned so that it can be used as glass for solar cells. Here, the reason why the lower limit value of the strength of the semi-strengthened glass is 1.20 times that of the soda-lime glass (raw glass) in the state of being unmolded is that the worker has a strength lower than this at the time of solar cell installation work. Can not withstand natural disasters such as trampling, cracking and falling rocks, and the function as a protective cover is lost.To prevent this, it is necessary to increase the thickness of the glass, which increases the weight and costs. Because it becomes. On the other hand, the reason why the upper limit of the strength of the semi-strengthened glass is 1.70 times that of the green glass is that if the strength exceeds this, the residual compressive force of the surface layer becomes excessive, and it is difficult to cut cleanly along the planned cutting line. Because it becomes.

  In FIG. 3, the horizontal axis represents the substrate thickness (mm) and the vertical axis represents the steel ball 227g drop height (m), and the strength of each glass substrate was measured. According to the steel ball 227g drop height test specified in JIS standard C8938, the strength of three types of tempered glass, semi-tempered glass, and green glass with various thicknesses in the range of 3-8mm was examined. did.

  B) The semi-tempered glass of the present invention has cleared the weather resistance standard (withstands the impact force of dropping 227 g of steel balls from a height of 1 m) defined by JIS standards at all practical plate thicknesses (3 to 8 mm). . That is, the semi-tempered glass has a steel ball 227g drop height of 1.2 to 2.2 m when the plate thickness is 3 mm, and a steel ball 227 g drop height of 1.5 to 2.6 m when the plate thickness is 6 mm. When the thickness was 8 mm, the steel ball showed a strength of 2.1 to 3.8 m at a drop height of 227 g.

  B) The strength of the tempered glass, semi-tempered glass, and green glass increased gradually as the plate thickness increased. That is, when the plate thickness was increased from 3 mm to 8 mm, the steel ball 227 g dropped by about 1 to 1.5 m.

  A curve E1 in FIG. 3 indicates a lower limit condition of the substrate strength that can be cut by the semi-strengthening process, and a curve E2 indicates an upper limit condition of the substrate strength that can be cut by the semi-strengthening process. Also, the alternate long and short dash line C indicates the strength of the steel ball 227g drop height 1m as the weather resistance standard defined in the JIS standard.

  The destruction of glass exhibits two phases: a quasi-static thermal process and an adiabatic process in which cracks grow rapidly, and the boundary is determined by the critical fracture energy Gc. When the semi-strengthened glass of the present invention is cut, energy exceeding the critical fracture energy Gc is applied to the glass substrate by the cutting means, and a crack in the heat insulating process in which the cracks are rapidly extended is generated. As a result, a sharp cut surface with few chips and cracks can be obtained.

As described above in detail, according to the present invention, when a plurality of small solar cells are divided from a large glass substrate, a method for producing a semi-strengthened glass substrate suitable for cutting can be provided.

  In addition, since the film forming process and the semi-strengthening process can be integrated by optimizing the film forming conditions of the transparent electrode, an existing heat treatment apparatus for transparent electrodes can be used without newly establishing a dedicated heat treatment furnace. The glass substrate can be semi-strengthened. For this reason, an increase in operating cost and equipment cost can be suppressed.

  Hereinafter, various preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  First, a solar cell manufacturing method using an amorphous silicon solar cell as an example will be described with reference to FIGS.

  At least a section from the transparent electrode forming step S1 to the dividing step S7 in the solar cell production line is configured as a fully automatic integrated production line controlled by a computer so that the glass substrates 4 flow one after another on the conveyance path. The section after the power generation inspection step S8 is sorted by product size by the operator, individually inspected using an inspection device, and the sealing material is sealed around the solar cell panel and the terminal block using the sealing device. It is a semi-automatic line that injects necessary parts, stores them in a temporary storage place, aged sealing materials, and packs them using a packing device.

  The glass substrate 4 is received in the substrate receiving unit, and the substrates 4 are sorted into lots and stored in a temporary storage. The size of the glass substrate 4 is, for example, plate thickness 3 mm × width 1000 mm × length 1000 mm. The glass substrates 4 are taken out from the temporary storage one by one, placed on a conveyance path, conveyed to a barcode printing device, and a barcode for identification is printed on the substrate 4. Further, the substrate 4 is conveyed to a cleaning processing apparatus, the substrate 4 is cleaned, and the adhered foreign matter is removed from the surface.

  The substrate 4 is carried into a heat treatment furnace 44 shown in FIG. 4 and preheated to about 450 to 500 ° C. The preheated substrate 4 is carried into a thermal CVD apparatus (or an ion plating apparatus or a sputtering apparatus), and a transparent electrode 11 having a predetermined film thickness is formed on one side (cleaning surface) of the glass substrate 4 (step S1). The film thickness of the first transparent electrode 11 is about 750 nm.

  When the received substrate 4 is physically strengthened glass, the substrate 4 is semi-strengthened by the heat treatment furnace 44 used for the preheating. Although the substrate 4 is placed on the belt conveyor 42 and heated by the heater 45 while being conveyed in the heat treatment furnace 44, it is not necessary to rapidly cool the substrate 4. The semi-strengthening treatment condition is to heat and hold in a temperature range of 400 to 550 ° C. for 20 to 30 minutes, and immediately thereafter, gradually cool at a cooling rate of about 100 ° C./minute. As a result, the strength of the glass substrate 4 is halved to about 50% of the initial strength (about 1.5 times that of the green glass), and the required strength as a solar cell cover glass is secured along the planned dividing lines 31 and 32. It becomes the strength level that can be cut.

  In this embodiment, the heat treatment furnace used for preheating before forming the transparent electrode is used for the semi-strengthening treatment of the glass substrate. However, the glass substrate is half-heated using another heat treatment furnace provided separately from this. You may make it strengthen processing. In addition, when the received substrate 4 is not tempered glass, for example, when it is in a semi-tempered state having a strength about 1.5 times that of raw glass, and the raw glass that secures the required strength although there is a problem of weight increase, this heat treatment Can be omitted. In addition, the intensity | strength of the glass substrate 4 can be measured with a certain amount of precision not only by the steel ball 227g drop test shown in FIG. 3 but by the optical nondestructive inspection using a moire interference fringe.

  After the heat treatment, the substrate 4 is transferred to the cleaning processing apparatus, the substrate 4 is cleaned, and then the substrate 4 is transferred to, for example, a laser etching apparatus to etch the transparent electrode 11 into a predetermined pattern (step S2).

  Next, the substrate 4 is transferred to a plasma CVD film forming apparatus, and an amorphous silicon layer 12 is formed on the transparent electrode 11 subjected to pattern etching (step S3). The total film thickness of the a-Si layer 12 is about 400 nm, for example.

  Next, for example, the substrate 4 is conveyed to a laser etching apparatus, and the a-Si layer 12 is etched into a predetermined pattern (step S4).

  Next, the substrate 4 is conveyed to an ion plating apparatus (or a sputtering apparatus or a CVD apparatus), and a metal electrode 13 made of, for example, aluminum is laminated and formed on the a-Si layer 12 subjected to pattern etching (step). S5). The film thickness of the metal electrode 13 is about 500 nm, for example.

  Next, for example, the substrate 4 is conveyed to a laser etching apparatus, and the metal electrode 13 is etched into a predetermined pattern (step S6). In this etching step S6, an electrical short circuit at the cut surface is prevented by forming an insulating band that completely removes up to the transparent electrode 11 along a planned cutting line in a dividing step S7 described later.

  Thus, the laminated body 9 in which the power generation function layers 11, 12, and 13 are sequentially laminated on the substrate 4 is conveyed to a laminator device, and, for example, the thermally adhesive EVA sheet 3 and the water-resistant back cover sheet 5 are laminated. The panel 10 is laminated on the laminated surface 9 and pressed at a predetermined pressure while being heated to about 150 ° C., and joined to form an integrated panel 10. The adhesive protruding outside from the panel 10 is removed by the trimming unit and further heated in a crosslinking furnace to promote the crosslinking reaction of the adhesive, and then cooled to room temperature in the cooling unit. Next, the panel 10 is transported to the terminal block mounting portion, the plus terminal is attached to the transparent electrode 11, the minus terminal is attached to the metal electrode 13, and wiring is performed. The panel 10 is conveyed to an aging unit, and the adhesive is dried and cured.

  Next, the panel 10 is transported to a cutting machine, and the panel 10 is collectively cut from the glass substrate 4 side or the back cover sheet 5 side (step S7). The panel 10 is placed on the XY table, and the panel 10 is cut by the cutting means while moving the panel together with the XY table. Thus, the panel 10 is divided into a plurality of solar cells 1A having a desired size. In the present embodiment, the same panel is divided so as to obtain four small-sized solar cells 1A of the same size shown in FIG. 1B from one panel 10 shown in FIG. The size of the divided solar cell 1A is approximately 500 mm wide × 500 mm long.

  The cutting machine as the cutting means can use various means and methods as will be described later. Further, in this embodiment, an example in which the panel is equally divided into four has been described. However, the present invention is not limited to this, and the panel is divided evenly into solar cells of different sizes by changing the planned cutting line. It is also possible to divide the panel into two, six and eight.

  The solar cell 1A is transported to the trimming unit, the cut end face is ground and polished, and the terminals are wired. Next, simulated sunlight is irradiated on the glass substrate 4 side using a power generation inspection device, and a power generation current is passed through a load connected between the electrodes 11 and 13 to inspect the power generation capability of the solar cell 1A (step S8). .

  Solar cells 1A that have passed in step S8 are sorted by product size. A sealing device is used for each size to inject a sealing material around the solar cell 1A and necessary parts such as a terminal block, and if necessary, a rubber frame or an aluminum frame frame is fitted and bonded to the outer peripheral edge as needed. Store in a storage location and age the encapsulant. Thereby, solar cell 1A is completed as a product, and is packed and shipped by a packing device.

  Next, various examples of the semi-strengthening process will be described.

(Example 1)
After laminating the transparent electrode 11, physically tempered glass with soda lime glass (composition: SiO ₂ : 70 to 74%, Na ₂ O: 12 to 16%, etc.) called blue plate (or white plate) glass is used. It was heated and held at a temperature of 455 ± 5 ° C. for about 20 minutes, and then slowly cooled at a cooling rate of about 100 ° C./min and then carried out.

  As a result, a strength of 1.6 m was obtained at a drop height of 227 g of steel balls.

(Example 2)
Physically tempered glass of 4 mm thick soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 455 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and a cooling rate of about 100 ° C./min It was slowly cooled and carried out.

  As a result, a strength of 1.8 m was obtained at a drop height of 227 g of steel balls.

(Example 3)
Physically tempered glass of 3 mm thick soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 500 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and a cooling rate of about 100 ° C./min. It was slowly cooled and carried out.

  As a result, a strength of 1.0 m was obtained at a drop height of 227 g of steel balls.

(Example 4)
Physically tempered glass of 4 mm thick soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 500 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and a cooling rate of about 100 ° C./min. It was slowly cooled and carried out.

  As a result, a strength of 1.2 m was obtained at a drop height of 227 g of steel balls.

(Example 5)
A soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 450 ± 5 ° C. for about 20 minutes with a physical tempered glass having a thickness of 3 mm serving as a film forming condition of the transparent electrode (SnO ₂ film) 11. Then, it was slowly cooled at a cooling rate of about 100 ° C./min and carried out.

  As a result, a strength of 1.8 m was obtained at a drop height of 227 g of steel balls.

(Example 6)
A soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 450 ± 5 ° C. for about 20 minutes with a physical tempered glass having a thickness of 4 mm serving as a film forming condition of the transparent electrode (SnO ₂ film) 11. Then, it was slowly cooled at a cooling rate of about 100 ° C./min and carried out.

  As a result, a strength of 2.0 m was obtained at a drop height of 227 g of steel balls.

  In Examples 5 and 6, the film forming conditions of the transparent electrode are optimized, and the film forming process and the semi-strengthening treatment process are integrated, so that existing equipment can be used without introducing a new apparatus. Therefore, there is an advantage that increase in operation cost and equipment cost can be suppressed.

(Example 7)
Soda lime glass called blue plate (or white plate) glass, raw plate glass having a thickness of 3 mm, is heated and held at a temperature of 510 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and immediately at room temperature (about 23 ° C.) The air was blown onto the substrate 4 for rapid cooling.

  As a result, a strength of 1.2 m was obtained at a drop height of 227 g of steel balls.

(Example 8)
Soda lime glass called blue plate (or white plate) glass, raw plate glass having a thickness of 4 mm is heated and held at a temperature of 510 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and immediately at room temperature (about 23 ° C.) The air was blown onto the substrate 4 for rapid cooling.

  As a result, a strength of 1.4 m was obtained at a drop height of 227 g of steel balls.

(Comparative Example 1)
Physically tempered glass of 3 mm thick soda lime glass called blue plate (or white plate) glass is heated and held at a temperature of 550 ± 5 ° C. for about 20 minutes after lamination of the transparent electrode 11, and a cooling rate of about 100 ° C./min It was slowly cooled and carried out.

  As a result, only a strength of 0.7 m was obtained at a drop height of 227 g of steel balls.

(Comparative Example 2)
A soda lime glass called blue plate (or white plate) glass is simply heated and held at a temperature of 550 ± 5 ° C. for about 20 minutes while also serving as a film forming condition for the transparent electrode (SnO ₂ film) 11. The rapid cooling operation was not performed.

  As a result, only a strength of 0.7 m was obtained at a drop height of 227 g of steel balls.

  Next, the cutting means and method used in the dividing step S7 will be described with reference to FIGS.

  A wheel cutter 20 shown in FIGS. 6 and 7 was used as a cutting means. The cutter blade 24 of the wheel cutter 20 is made of a cemented carbide harder than hard glass. The cutter blade 24 is supported by a holder 22 so as to be rotatable around a shaft 23, and the holder 22 is connected and supported by a support arm 21 driven by a robot (not shown). The robot is equipped with an optical sensor, and the cutting line is detected by the optical sensor, or the position is set in advance by a program, and the support arm 21 is driven and controlled based on this, and the cutter blade of the wheel cutter 20 is controlled. 24 is pressed against the glass substrate 4 at a predetermined pressure, and is moved relative to the planned cutting line position. That is, the panel 10 is placed on the XY table, the cutter blade 24 is pressed on the planned cutting line of the panel 10, and the panel 10 is moved together with the XY table to cut out the panel 10.

  The cutting edge 24 of the cutter blade 24 is moved while being pressed against the surface of the glass substrate 4 to form a notch 8a having a depth of less than about 0.5 mm. Next or simultaneously, the back cover sheet 5 is cut with another cutter blade following the planned cutting line of the back cover sheet 5. Next, the glass substrate 4 is pressed and broken by applying a pressing force to the notch 8a. At this time, only the vertical crack 8b develops from the notch 8a, and the horizontal crack 8c does not substantially propagate at all, so that a clean cut surface is obtained. Such a glass splitting method is the same as the principle used for ampule cutting by a file or general glasswork, for example. Thereafter, chamfering is performed so that chips and cracks do not remain on the cut end face.

  When the wheel cutter 20 of this example was used, the cutting speed was about 4 to 6 m / min. Moreover, according to the cutting method of the present Example, the cutting allowance was able to be suppressed to 0.2 mm or less. In addition, by using the XY table, the panel can be moved relative to the cutting means with high accuracy, and can be suppressed to within ± 1 mm (actual power within ± 0.5 mm) from the planned cutting line.

  In addition, by selecting a hard cutter blade here, the back cover sheet can be cut off, and at the same time, scratches with a predetermined depth can be applied to the glass substrate from the back side of the glass substrate together with the laminated film. it can.

  In addition, although the present Example demonstrated the example which forms a notch in a glass substrate using the wheel cutter made from a cemented carbide, the same effect is acquired even if it uses a diamond cutter in addition to this.

  Next, another cutting means and method will be described with reference to FIG.

As another cutting means, an energy beam such as a CO ₂ gas laser cutting device was used. The wavelength (10.6 μm) of the CO ₂ gas laser beam is easily absorbed by the glass, and the thermal energy conversion efficiency is high. This is because the irradiation laser light can supply the amount of heat energy necessary for cutting the glass. The CO ₂ gas laser cutting device includes an automatic focus alignment mechanism, a scanning sensor, a mechanism for setting a numerical value by a program, and a laser emission unit supported by a scanning arm. The laser beam 30 excited from the oscillator is oscillated, and the optical focus position is adjusted so that the laser beam 30 is focused on the cutting line of the back cover sheet 5 of the panel 10 by a plurality of optical lenses, and the cutting line is cut by the scanning sensor. By controlling the operation of the scanning arm based on the detection signal, or by controlling the operation with a program in which numerical values are set in advance, the laser beam emitted from the laser emitting unit is scanned and irradiated to the planned cutting line position. It has become. The diameter of the laser beam can be reduced to a minimum of 0.05 mm.

  Further, the nozzle of the gas cooling mechanism is scanned so as to follow the laser emitting portion, and the cooling gas is sprayed on the portion immediately after cutting. It is desirable that the nozzle of the gas cooling mechanism sprays the cooling gas simultaneously on both sides of the panel cutting part. Note that it is preferable to use low-temperature air or nitrogen gas as the cooling gas.

  When the laser beam is irradiated, first, the back cover sheet 5 is burned out, and then the light is incident from the irradiation point 31 to the glass substrate 4 almost vertically or slightly obliquely so that the reflected light does not return to the racer emitting portion. Is rapidly heated, and immediately after that, it is rapidly cooled by blowing a cooling gas. The glass substrate 4 is split along the split surface 32 by this rapid heating and cooling.

  Moreover, in the thing with thick plate | board thickness, the glass substrate 4 may not fully be cut | disconnected by rapid cooling. At this time, the back cover sheet 5 is burned out by the laser beam along the planned cutting line of the panel, and after the vertical crack is formed in the surface layer of the glass substrate 4, it is divided along the split surface 32 by using the press splitting together. .

Here, the CO ₂ gas laser described a method for cutting collectively from the back cover sheet 5 side, in order to increase the cutting accuracy of the glass substrate 4, CO ₂ from the both side of the glass substrate front side and backside cover sheet 5 In some cases, a gas laser is irradiated. Thereafter, chamfering is performed so that chips and cracks do not remain on the cut end face.

In this example, when a CO ₂ gas laser cutting device having an output of about 10 kW was used, the cutting speed was about 5 to 10 m / min. Further, according to the cutting method of this example, the cutting allowance could be suppressed to 0.3 mm or less. In addition, by using the XY table, the panel can be moved relative to the cutting means with high accuracy, and can be suppressed to within ± 1 mm (actual power within ± 0.5 mm) from the planned cutting line.

  Furthermore, a water jet cutting device was used as another cutting means. A water jet stream containing abrasive grains is sprayed along the planned cutting line of the glass substrate 4 or the back cover sheet 5. In this case, for example, garnet particles are preferably used as the abrasive grains contained in the water jet. Thereby, the chamfering polishing operation after cutting can be omitted or reduced.

  When a water pressure of about 300 Pa was applied to about # 150 garnet abrasive grains using the water jet cutting device of this example, the cutting speed was about 0.5-3 m / min. Moreover, according to the cutting method of a present Example, the cutting allowance was able to be 1-2 mm. In addition, by using the XY table, the panel can be moved relative to the cutting means with high accuracy, and can be suppressed to within ± 1 mm (actual power within ± 0.5 mm) from the planned cutting line.

  In the above embodiment, the case of collectively cutting a panel having a size of 3 mm in thickness, 1000 mm in width, and 1000 mm in length has been described. However, the present invention is not limited to this and is, for example, 3-6 mm in thickness × 1500-2500 mm in width. X It is also possible to collectively cut a large panel having a length of 1500 to 3000 mm.

(A) is an exploded perspective view showing a panel before cutting in order to explain the method of the present invention, (b) is an exploded perspective view showing a panel after cutting in order to explain the method of the present invention. The flowchart which shows the manufacturing process of the solar cell using the semi-strengthening processing method of the glass substrate for solar cells which made the amorphous silicon solar cell which concerns on embodiment of this invention an example. The characteristic line figure which shows the steel ball drop test result of various glass substrates. The schematic block diagram which shows the heat processing line of a glass substrate. The cross-sectional schematic diagram which expands and shows a part of solar cell panel which used the amorphous silicon solar cell as an example. The partial cross-section schematic diagram which shows the glass substrate under cutting | disconnection using the method of 1st Embodiment seeing from the direction orthogonal to a cutting line. The partial cross section schematic diagram which shows the glass substrate under the cutting | disconnection using the method of 1st Embodiment seeing from a direction parallel to a cutting line. The perspective view which shows the glass substrate in process of cutting | disconnection using the method of 2nd Embodiment. (A) is an exploded perspective view showing a panel before cutting in order to explain a conventional method, (b) is an exploded perspective view showing a panel after cutting in order to explain a conventional method.

Explanation of symbols

1 ... Panel,
1A ... solar cell,
2 ... Solar cell module,
3 ... Adhesive sheet (EVA sheet),
4 ... Glass substrate (cover glass),
5 ... Back cover sheet,
8a, 8b, 8c ... cracks,
9 ... laminate,
10 ... Panel,
11 ... Transparent electrode,
12 ... a-Si film,
13 ... Metal electrode,
20 ... Glass cutter,
21 ... Support arm,
22 ... Holder,
23 ... axis,
24 ... wheel cutter,
30 ... Laser light,
31 ... irradiation point,
32 ... Split face.

Claims (1)

A glass substrate for a solar cell that serves as a cover for protecting the power generation functional layer, is directly laminated, is cut after the power generation functional layer is laminated, and is divided into a desired product size a method of manufacturing a Namaita glass as a starting material, before laminating the power generation function layer, by a biological glazing predetermined time heating and holding the temperature range of 500-550 ° C., and then quenched, the intensity Is a range from 1.20 times to 1.70 times the strength of soda-lime glass in a state of being unmolded, and a method for producing a glass substrate for a solar cell.

Images