JP2011135068A - Method for manufacturing solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a solar cell module excellent in design and power generation efficiency. <P>SOLUTION: The method for manufacturing a solar cell module by pressing a laminated module members where solar cell elements are arranged via fillers between a substrate and a protective material includes: a first step of heating the fillers to a temperature equal to or higher than the melting point thereof; a second step of increasing the pressure of press from that in the first step acceleratedly; a third step of keeping the increased pressure; a fourth step of reducing pressure from the pressure kept in the third step; and a fifth step of keeping pressure lower than that kept in the third step for a longer period of time than that in the third step. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a solar cell module.

  In general, a solar cell module has a laminated structure in the order of a translucent substrate, a light receiving surface side filler, a plurality of solar cell elements electrically connected to each other by a conducting wire, a back surface side filler, and a back surface protective material. is doing.

  This laminated structure (module laminated body) is a laminating step in the manufacturing process of a solar cell module. The module laminated body is placed on a heater panel of a laminator, the housing is closed and the pressure is reduced, and then the module laminated body is pressurized. Integration was performed by heating the heater panel.

  However, the conventional laminating process has a problem that the filler flows out from the peripheral portion of the solar cell module during pressurization, and the thickness of the filler at the peripheral portion of the solar cell module tends to be thin.

  Therefore, for the purpose of manufacturing a solar cell module having a sufficient thickness of filler at the peripheral edge, a method for manufacturing a solar cell module is disclosed in which the module stack is pressed and heated in the frame (for example, Patent Document 1).

  Furthermore, in order to prevent cracking of the solar cell element in the laminating process, a method for manufacturing a solar cell module in which the module laminate is pressed at a low pressure for a long time is disclosed (for example, Patent Document 2).

JP 2000-31519 A JP 2008-294486 A

  However, in the method for manufacturing a solar cell module described in Patent Document 1, the time during which the maximum pressure is applied after the temperature rise occupies about half of the laminating step, and the light receiving surface of the solar cell element as shown in FIGS. As a result, the back side filler colored on the side wraps around, making the appearance of the solar cell element uneven, blocking incident light on the light receiving surface side of the solar cell element, and reducing power generation efficiency. It was.

  Moreover, in the manufacturing method of the solar cell module described in Patent Document 2, priority is given to prevention of cracking of the solar cell element, and the laminating process is pressurized at a low pressure for a long time. Therefore, productivity is low and it is not suitable for actual manufacturing. There was a problem.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a method for manufacturing a solar cell module excellent in appearance and power generation efficiency.

The method for manufacturing a solar cell module according to the present invention is a method for manufacturing a solar cell module in which a module laminate in which a solar cell element is arranged between a substrate and a protective material via a filler is used. A first step of increasing the pressure of the press, a second step of increasing the pressure of the press at an accelerated rate, a third step of maintaining the pressure, and a fourth step of reducing the pressure from the pressure held in the third step. And a fifth step of holding the pressure for a time longer than that of the third step at a pressure lower than that of the third step.

  According to the method for manufacturing a solar cell module of the present invention, in the method for manufacturing a solar cell module for pressing a module laminate in which a solar cell element is arranged between a substrate and a protective material via a filler, the filler is The first step of raising the temperature to a temperature equal to or higher than the melting point, the second step of increasing the pressure of the press at an accelerated rate, the third step of holding the pressure, and reducing the pressure from the pressure held in the third step. A solar cell module is manufactured with a low load and a short tact time by including a fourth step and a fifth step of holding the pressure for a longer time than the third step at a pressure lower than that of the third step. In addition, a solar cell module excellent in appearance and power generation efficiency can be manufactured.

  In addition, according to the solar cell module of the present invention, the solar cell element includes a first filler on the light receiving surface side that sandwiches the solar cell element from the front and back sides, and a second filler on the non-light receiving surface side. A solar cell module having a wedge portion outside the region on the light-receiving surface, wherein a part of the second filler extends into the first filler, so that the light-receiving surface side due to a wedge effect Peeling between the filler and the back surface side filler can be reduced.

It is a sectional side view which shows the manufacturing method of the solar cell module of this invention, (a) is a sectional side view which shows a 1st process, (b) is a sectional side view which shows a 2nd process and a 3rd process. (C) is a sectional side view which shows a 4th process and a 5th process. It is a disassembled perspective view of a solar cell module, (a) is a perspective view showing a solar cell matrix formed by connecting a plurality of solar cell elements with connecting conductors, (b) is a translucent substrate, a light receiving surface side filler, It is a disassembled perspective view explaining the lamination | stacking state of the module laminated body which consists of a solar cell matrix, a back surface side filler, and a back surface sheet. It is a schematic diagram which shows a solar cell module, (a) is the top view seen from the light-receiving surface side, (b) is a sectional side view seen from the A-A 'cross section direction in (a). It is a graph which shows temperature and pressure in the manufacturing method of the solar cell module of this invention. It is a schematic diagram which shows the conventional solar cell module, (a) is a top view, (b) is the sectional side view which looked at (a) from the B-B 'cross section. It is a partial expanded sectional view of a solar cell module. It is a partial expanded sectional view of the conventional solar cell module. (A) is drawing substitute photograph which shows the external appearance of a solar cell module, (b) is drawing substitute photograph which shows the conventional solar cell module.

  One embodiment of a method for manufacturing a solar cell module according to the present invention is a method for manufacturing a solar cell module in which a module laminate in which a solar cell element is arranged between a substrate and a protective material via a filler is pressed. The first step of heating the substrate to a temperature equal to or higher than the melting point, the second step of increasing the pressure of the press at an accelerated rate, the third step of maintaining the increased pressure, and reducing the pressure from the pressure held in the third step. And a fifth step of holding the pressure for a longer time than the third step at a pressure lower than the pressure in the third step.

  First, in the first step, the temperature of the filler is set to the melting point or higher.

  In the second step, since the pressure is increased at an accelerated rate, the time during which the pressure is transiently pressed at a high pressure can be relatively shortened. In addition, in the second step, the increase in pressing pressure is moderate and the fluidity of the filler 22 is still low, so that a gap can be left until the module stack is deaerated.

  In the third step, by pressing with pressure, the primary bonding force due to chemical interaction between the adherend surface and the filler 22 and the intermolecular force due to physical interaction are increased, and the filler 22 flows on the entire adherend surface. By making it, the adhesive force can be increased. Further, in the third step, when the filling material 22 has high fluidity, the pressing time with a large pressure is shortened, the collapse of the shape of the filling material 22 at the end of the solar cell module is suppressed, and the solar cell element 25 receives light. The wraparound of the back surface side filler 22b to the surface side can be reduced, and the solar cell module 30 excellent in appearance and power generation efficiency can be manufactured.

  By reducing the pressure from the pressure in the third step in the fourth step, an excessive pressure can be lowered before the temperature of the filler in the fourth step is increased.

  By holding the pressure lower than that of the third step for a longer time than that of the third step in the fifth step, the time at the higher pressure of the third step can be reduced.

  Thereby, a solar cell module can be manufactured with a low load and a short tact time as a whole.

  Furthermore, it is preferable that the manufacturing method of the solar cell module of this invention raises the temperature of a filler from a 1st process to a 5th process.

  As a result, the problem of the slow follow-up of the temperature rise / fall is eliminated, and the pressure control according to the temperature rise is facilitated, so that the tact time is improved.

  Furthermore, in the method for manufacturing a solar cell module of the present invention, it is preferable that the pressure is reduced at an accelerated rate in the fourth step.

  Thereby, before fluidity | liquidity can fully go up by the temperature rise of the filler 22 in a 4th process, a pressure can be reduced more rapidly so that an excessive pressure may not be applied to the module laminated body 20. FIG.

  Furthermore, it is preferable that the manufacturing method of the solar cell module of this invention raises the temperature of a filler at high speed from a 3rd process to a 4th process.

  Thereby, temperature can be raised more rapidly so that it may become the temperature which can be made to flow the filler 22 to the whole to-be-adhered surface at a 5th process.

  Furthermore, in the method for manufacturing a solar cell module of the present invention, the pressure in the fifth step is preferably 5 to 25% of the pressure in the third step.

  Within this range, the filler 22 can be sufficiently flowed and supplied to the entire gap between the module stacks 20 without applying excessive pressure in a state where the fluidity of the filler 22 is high. it can.

In the method for manufacturing a solar cell module of the present invention, it is preferable that the time for holding the pressure in the fifth step is 1.5 to 2.5 times the time for holding the pressure in the third step.

  If it is this range, the filler 22 can fully flow and be supplied to the whole adherend surface with a low pressure.

  And the solar cell module of this invention is obtained by pressing a module laminated body using the manufacturing method of the said solar cell module.

  Thereby, the solar cell module excellent in appearance and power generation efficiency can be obtained.

  Further, according to the solar cell module of the present invention, the solar cell element, the first filler positioned on the light receiving surface side that sandwiches the solar cell element from the front and back, and the second filler positioned on the non-light receiving surface side. A solar cell module comprising a filler, and located outside the region on the light receiving surface of the solar cell element, wherein a part of the second filler has a wedge portion extending into the first filler. is there.

  Thereby, since the light-receiving surface side filler 22a which is the wedge part 31 bites into the back surface side filler 22b, the solar cell which reduced peeling with the light receiving surface side filler 22a and the back surface side filler 22b by the wedge effect. You can get a module.

  Moreover, it can be controlled by managing the length, the width | variety, and the range which the wedge part 31 bites in whether it is in the state laminated | stacked appropriately.

  As an inspection method, a destructive inspection may be performed and a cross-sectional view may be performed. However, it is possible to observe the wedge portion 31 with a CCD camera from an oblique direction on the light receiving surface side.

  Furthermore, it is preferable that the second filler protrudes into the first filler at the side of the solar cell element.

  Thereby, the side part 32 of a solar cell element is not exposed to the space | gap when it generate | occur | produces by peeling with a 1st filler and a 2nd filler, and is not eroded.

  Hereinafter, the manufacturing method of the solar cell module of this invention is demonstrated using FIG.

(First step)
FIG. 1 is a side sectional view of a laminator 1 in a first step in the method for manufacturing a solar cell module of the present invention, and a module laminate 20 is placed in the laminator 1. As shown in FIG. 2, the module laminate 20 includes a translucent substrate 21, a light receiving surface side filler 22a, a solar cell matrix 23 in which solar cell elements 25 are electrically integrated by a conductor 26, and a back surface side. It is comprised in order of the filler 22b and the back surface protection material 24. In particular, the back surface side filler 22b may be colored from the viewpoint of improving the appearance and power generation efficiency.

  First, as shown in FIG. 1A, the module laminate 20 is placed on the heating plate 8 in the lower housing 3 of the laminator 1 so that the translucent substrate 21 faces down, and the upper housing 2 Is lowered to the lower housing 3 side to close the housing, and the whole is decompressed while heating the module laminate 20 to a temperature equal to or higher than the melting point temperature of the filler 22. For example, when EVA (ethylene / vinyl acetate copolymer resin) is used for the filler 22, the melting point thereof is about 60 ° C. to 75 ° C., and the module laminate is formed so that the temperature of the entire filler 22 is equal to or higher than the melting point temperature. 20 is preferably heated to 75 ° C to 85 ° C. As other fillers, fillers based on polyolefin may be used.

  In addition, the translucent board | substrate 21 can use white board tempered glass, an acrylic board, a polycarbonate board etc., for example. Further, as the back surface protective material 24, for example, a PET resin sheet, a PEN resin sheet, a PVF resin sheet, glass, or a laminate thereof can be used.

(Second step)
Next, when the pressure in the upper vacuum region 5 is stopped and the pressure is maintained, a pressure difference is generated between the upper vacuum region 5 and the vacuum region 6 as shown in FIG. 1B, and the diaphragm sheet 4 expands. Then, the module laminate 20 is pressed.

  Here, preferably, the pressure is increased in an acceleration (exponential) manner, that is, the pressure is gradually increased in the first half of the second step and rapidly increased in the second half.

  In the first half of the second step, since the pressure increase is gradual, there are many gaps through which air molecules can pass between the translucent substrate 21, the filler 22, the solar cell matrix 23, and the back surface protective material 24, and the module Air bubbles in the laminate 20 can be degassed to the vacuum region 6, and the molten filler 22 can be poured into a macro shape such as a gap or unevenness of the solar cell matrix 23.

  In the second half of the second step, by applying a high pressing force, the primary binding force due to chemical interaction and the intermolecular force due to physical interaction are increased, and the filler 22 is caused to flow in the in-plane variation of the adherend. An anchoring effect can be produced and the adhesive strength can be increased. Moreover, since the increase in the pressure of the second half of the second step is abrupt, the time during which the pressure of the high pressure is applied is shortened, and the flow of the filler at the corners of the module laminate 22 can be suppressed. it can.

  Thus, even if the fluidity of the filler 22 is increased at a high temperature in the second half of the second step, the time during which a high pressure is applied is short, so that the filler 22 at the end of the module laminate 20 is horizontally oriented. Difficult to flow.

  Therefore, it can reduce as shown in FIG. 6 that the colored back surface side filler 22b as shown in FIG. 7 covers the light receiving surface side of the solar cell element 25 and prevents power generation.

  Although the pressing force in the second step varies depending on the specification of the filler 22, for example, when EVA (ethylene / vinyl acetate copolymer resin) is used, the maximum pressure may be 45 kPa to 200 kPa.

  Moreover, it is preferable that the temperature of the module laminated body 20 in a 2nd process increases at 75 to 110 degreeC.

  Also, the holding time of the pressing force in the second step is 130 to 250 seconds so that the filler 22 does not wrap around the light receiving surface side of the solar cell element 25 and does not protrude around the module laminate 20. It is preferable that

(Third step)
Next, the boosting of the upper vacuum region 5 is stopped.

  If the primary bonding strength between the layers of the module laminate is sufficient in the second step, the pressing force may be lowered directly by moving to the fourth step.

  If the primary bonding force between the layers of the module laminate is insufficient in the second step, the pressing force may be maintained as the third step so that the primary bonding force is increased.

  The holding time is preferably the minimum time for securing the adhesive force from the viewpoint of preventing the back surface side filler 22b from covering the light receiving surface side of the solar cell element 25, and is preferably 100 seconds or less. .

(4th process)
Next, the upper vacuum region 5 is depressurized, and the diaphragm sheet 4 is contracted as shown in FIG. 1 (c), so that the pressing force to the module stacked body 20 is lower than the pressure in the third step.

(5th process)
Next, the module laminate 20 is held for a longer time than the third step in a state where a pressing force lower than that in the third step is applied, so that the translucent substrate 21, the solar cell matrix 23, the back surface protective material 24, and It is possible to increase the primary bonding force and intermolecular force to increase the adhesive force by adapting the filler 22 to a uniform and stable micro shape.

  By providing the fifth step, the time for pressing with a high pressure in the third step can be shortened. The pressing force in the fifth step is preferably 4 to 25% of that in the third step, and specifically, the pressing may be performed with a pressure of 2 kPa to 50 kPa.

  After passing from the first step to the fifth step, the upper vacuum region 5 and the lower vacuum region 6 are returned to atmospheric pressure, the upper housing 2 is opened, and the laminated module laminate 20 is taken out.

  The laminated module laminate 20 is heated in a crosslinking furnace until the degree of crosslinking of the filler 22 becomes 90% or more. The heating temperature is preferably maintained at 120 to 150 ° C.

  Further, after the fifth step, the module laminate 20 is kept warm by a laminator at 100 to 120 ° C. within the total time of the first step to the fifth step, preferably 5 to 10 minutes, and then filled in a crosslinking furnace. More preferably, the temperature is further raised until the degree of crosslinking of 22 is 90% or more.

  Even if the deaeration is sufficient, the fluidity of the filler 22 is not sufficiently increased, and even when the filler 22 does not sufficiently surround the solar cell element 25, the temperature of 80 ° C. after the fifth step is increased. By adjusting the time for keeping the temperature at ˜120 ° C. and flowing the filler 22, the gap around the solar cell element 25 can be tightly sealed with the filler 22.

  Alternatively, after the fifth step, instead of the laminator described above, the module laminate 20 is subjected to a tunnel-type bridging furnace at 80 to 120 ° C. within the total time of the first step to the fifth step, preferably 3 to After holding for 10 minutes, the temperature may be further increased until the degree of crosslinking of the filler 22 reaches 90% or more.

  Similarly to the above, a solar cell module in which the periphery of the solar cell element 25 is tightly sealed with the filler 22 can be obtained.

  Thereafter, the terminal box 27 made of polyphenylene ether resin or the like is fixed to the non-light-receiving surface side with an adhesive, and the solar cell module is manufactured.

  In order to confirm the effect of the present invention, a solar cell module using the manufacturing method of the present invention and a solar cell module manufactured by a conventional method that monotonously increases the pressing force from the second step to the fifth step are prepared. A comparison was made.

  In the embodiment of the present invention, in the first step, the module laminate 20 is placed in the laminator 1 on the heating plate 8 in the lower housing 3 of the laminator 1 so that the translucent substrate 21 is located below. The upper housing 2 is lowered to the lower housing 3 side to close the housing, and the module laminate 20 is heated to 85 ° C., which is higher than the melting point temperature of EVA (ethylene / vinyl acetate copolymer resin) as the filler 22. The entire housing 2 was depressurized to a vacuum. Here, the translucent substrate 21 was made of white plate tempered glass, and the back surface protective material 24 was made of a PET resin sheet.

  In the second step, the diaphragm sheet 4 gradually increases the pressing pressure of the module laminate 20 in the first half and rapidly increases in the second half to 100 kPa at maximum, and the temperature of the module laminate 20 increases from 80 ° C. to 100 ° C. The holding time in the third step was 80 seconds.

  In the fourth step, the pressing force to the module laminate 20 was lowered than the pressure in the third step, and in the fifth step, the pressure was held for 100 seconds. The pressing force in the fifth step was 25% of the third step and was pressed at a pressure of 25 kPa (total required time 300 seconds).

  As a conventional example, the process up to the first step was the same as in the example, and thereafter, pressing was performed at 85 ° C. and a pressure of 25 kPa for 300 seconds.

  In the solar cell module using the manufacturing method of the present invention, the side portion 32 of the solar cell element 25 is not covered by the back surface side filler 22b as shown in FIGS. It has been confirmed that the side portion 32 of the present invention has a linear appearance and can maintain high power generation efficiency.

  In the solar cell module manufactured by the conventional method, as shown in FIG. 5 and FIG. 7B, about 1.2 mm to 2 mm of the side portion 32 of the solar cell element 25 is filled with the colored back surface side. The appearance was covered with the material 22b and the side portions 32 of the solar cell elements 25 meandered.

  Furthermore, it was covered with the colored back surface side filler 22b, and the problem that electric power generation efficiency fell was seen.

  If the back surface side filler 22b wraps around the side portion 32 evenly using the solar cell element 25 of 15 cm × 15.5 cm, the amount of power generation per solar cell element is calculated by area ratio. Is reduced by about 1.6% to 2.6%.

  Hereinafter, as an evaluation of the fluidity of the filler 22 in the present embodiment, the results of evaluating the presence or absence of a gap in the filler 22 will be described.

  Table 1 below shows.

  Samples 1 to 10 were evaluated by changing the temperature and time conditions in the fifth step. Here, the samples 3 and 8 have the same conditions.

  Samples 3, 4, 8, 9, and 10 were in good condition with no gaps.

  If the temperature is too low, the fluidity is low and therefore a gap remains (Sample Nos. 1 and 2), and if the temperature is too high, crosslinking occurs before flowing to leave a gap (Sample No. 5). When the time was too short, a gap remained (Sample 6), and when the time was too long, the profitability was poor (Sample 10).

  Next, samples 11 to 20 were evaluated by changing the temperature and time conditions in the crosslinking furnace in the subsequent process with respect to the sample in which the gap in the fifth process was observed. Here, the samples 13 and 18 have the same conditions.

  Samples 12-14 and 17-20 were in good condition with no gaps.

  If the temperature is too low, the fluidity is low and the gap remains (Sample No. 11). If the temperature is too high, the gap remains after crosslinking before flowing (Sample No. 15). Further, when the time was too short, the fluid could not flow sufficiently, leaving a gap (sample number 16), and when the time was too long, the profitability was poor (sample 20).

  Next, in order to verify the effectiveness of each process, the following experiments were performed as Comparative Examples 1 to 5 by changing some conditions of the first to fifth steps on the basis of the sample 3 of this example.

  In the sample (Comparative Example 1) in which the temperature of the filler 22 in the first step was lower than the melting point (65 ° C.), the fluidity of the filler 22 in the initial stage was poor and many gaps were observed.

  In the sample (Comparative Example 2) in which the pressure of the press in the second step was linearly increased, unevenness occurred in the wraparound of the filler 22.

  Further, in the sample from which the third step was omitted (Comparative Example 3), the fluidity was insufficient and many gaps were observed.

  Further, in the sample (Comparative Example 4) in which the pressure was maintained at a pressure lower than that of the third step (25 kPa) in the fifth step and for a shorter time (40 seconds) than that of the third step, many voids remained.

  In the sample (Comparative Example 5) in which the pressure was maintained at a higher pressure (150 kPa) than the third step in the fifth step and maintained for a longer time (100 seconds) than the third step, the protrusion of the filler 22 was often observed. .

  As described above, according to the present invention, it can be seen that each of the first to fifth steps works effectively.

1: Laminator 2: Upper housing 3: Lower housing 4: Diaphragm sheet 5: Upper vacuum area 6: Lower vacuum area 7: Upper vacuum pump 8: Heating plate
10: Lower vacuum pump 20: Module laminate 21: Translucent substrate 22: Filler 22a: Light receiving surface side filler 22b: Back surface side filler 23: Solar cell matrix 24: Back surface side protective material 25: Solar cell element 26 : Conductor 28: Frame 30: Solar cell module 31: Wedge 32: Side

Claims (9)

In the method of manufacturing a solar cell module for pressing a module laminate in which solar cell elements are arranged via a filler between a substrate and a protective material,
A first step of raising the filler to a temperature above the melting point;
A second step of acceleratingly increasing the pressure of the press;
A third step of maintaining the pressure;
A fourth step of reducing pressure from the pressure held in the third step;
And a fifth step of holding the pressure for a time longer than that of the third step at a pressure lower than that of the third step. The method for manufacturing a solar cell module according to claim 1, wherein the temperature of the filler is increased from the first step to the fifth step. 3. The method for manufacturing a solar cell module according to claim 1, wherein the pressure of the filler is acceleratedly decreased in the fourth step. 4. The method for manufacturing a solar cell module according to any one of claims 1 to 3, wherein the temperature of the filler is acceleratedly increased from the third step to the fourth step. The method for manufacturing a solar cell module according to any one of claims 1 to 4, wherein the pressure in the fifth step is 5 to 25% of the pressure in the third step. 6. The method of manufacturing a solar cell module according to claim 1, wherein the time of the fifth step is 1.5 to 2.5 times the time of the third step. A solar cell module, wherein the module laminate is pressed using the method for manufacturing a solar cell module according to claim 1. A solar cell module comprising: a solar cell element; a first filler positioned on the light receiving surface side that sandwiches the solar cell element from the front and back sides; and a second filler positioned on the non-light receiving surface side. ,
A solar cell module, wherein the solar cell module is located outside a region on a light receiving surface of the solar cell element and has a wedge portion in which a part of the second filler material extends into the first filler material. The solar cell module according to claim 8, wherein the second filler protrudes into the first filler at a side portion of the solar cell element.