JPS6124426A - Laminating and bonding device - Google Patents

Abstract

PURPOSE:To enable to seal solar cell elements at low cost by preventing the elements from cracking by a method wherein a method similar to vacuum packaging is employed to stick the solar cell elements sealed in between resin films on a support. CONSTITUTION:Molding chambers 1 and 1' are partitioned by a push plate 2, which is flexible and has restoring force such as of rubber sheet. A heater 4 is equipped in the one chamber 1'. Solar cell elements 15 and 15', which are put between resin sheet 14 and 14' made of ethylene-vinyl acetate or polyvinyl butyral and placed on a support 17 such as glass sheet of the like, are placed onto the heater so as to evacuate the chamber 1' in order to press the flexible push plate 2 against the solar cell elements by the force developed due to the atmospheric pressure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses EVA or PVB resin sheets for other members (for example, glass plates, thin plates such as aluminum plates),
It relates to lamination adhesives used for pasting solar cell elements and the like.

[Prior art]

In recent years, solar cells have been in the spotlight as an alternative energy source, but their cost is still several dozen times higher than conventional fossil energy. This requires not only a reduction in the cost of solar cell elements, but also a reduction in costs of other components. In particular, there are great expectations for cost reduction through mass production, so there is an urgent need to develop laminated materials, lamination methods, and equipment that enclose solar cell elements and provide weather resistance.

[Problem that the invention seeks to solve]

Recently, a device for laminating solar cell elements using these laminated members and resin sheets has been developed and commercially available.
Polycrystalline solar cell elements with low mechanical strength have the disadvantage of causing cracking and chipping of the element during adhesive sealing. In particular, since a solar cell module is made up of a plurality of elements connected in series and parallel and sealed with adhesive, even if one element cracks, the solar cell module will not be able to generate electrical output. Therefore, when producing solar cell modules, not only the yield is lowered but also the module cost is increased, making production difficult.

An object of the present invention is to provide a lamination adhesive device that does not cause cracking of elements.

[Means for solving problems]

The present invention divides the chamber 1 + 1' that accommodates the laminated member 3 of the solar cell element into two chambers 12 and 12', and connects the two chambers to a vacuum device through valves 9 and 8.
One chamber 12 of the chamber is connected to a variable leak valve 13°1.
A flexible pressing plate 2 that presses the laminated member 3 in response to a pressure difference between the two chambers is used as a partition member that is connected to the chamber through a valve and divides the inside of the chamber into two chambers. be.

[Effect]

A pressure difference is created between the chamber chambers 12 and 12' which are divided into two in the chambers 1 and 1', and the pressure is received by the suppression plate 2 to press the laminated member 3. An embodiment of the invention will be described with reference to the drawings.

In FIG. 1, chambers 1 and 1' are divided into two upper and lower chamber chambers 12 and 12' by a flexible pressing plate 2 made of, for example, a rubber plate with restoring force.
, 12', and each exhaust pipe 6, 7 is branched into two pipes.

The branch pipe 7a is opened to the atmosphere through a valve 10, and the other branch pipe 7b is communicated with a rotary pump (vacuum device) 11 through a valve 8. Further, the branch pipe 6a has a valve 9.
The two variable leak valves 13, 13' are connected in parallel through valves 10, 10'', and 101 to the other branch pipes.

As shown in FIG. 2, the laminated member 3 includes a glass plate 17, resin sheets 14, 14', and solar cell elements 15, 15'.
, a backing material 16 are laminated in this order. Laminated member 3
is placed on top of the heater 4 shown in Figure 1, and the chamber 1゜1'
The rotary pump 11 is operated, the valves 8 and 9 are opened, and the chamber chambers 12 and 12' are simultaneously evacuated. Gas and moisture present between the laminated members are completely degassed, and the laminated member 3 is heated to about 150° C. by the heater 4. Next, valve 9 is closed, valves 10 and 10'' are opened and connected to the first stage variable leak valve 13, and air is gradually introduced into the chamber 12 to about 0.5 atmosphere.

As a result, the pressure increases, and the suppressing plate 2 enters the state 2 shown by the dotted line, and gradually continues to suppress the laminated member 3 to a uniform pressure in accordance with the amount of leak from the variable leak valve 13. On the other hand, the resin sheets 14 and 14' are melted and begin to be bonded, and after maintaining the melting temperature completely, the valve 10'' is closed, the valve 10'' is opened, and the resin sheets 14 and 14' are connected to the second stage variable leak valve 13'. Air is gradually introduced to bring the chamber chamber 12 to 1 atmosphere, thereby perfecting the adhesion. At the same time, turn off heater 4.9
Then, cooling water is flowed through the cooling pipes 5 and 5' to cool it down to a temperature at which the laminated member can be taken out, and the valve 8 is closed and the valve 10' is opened to introduce air to open the chamber chamber 12°12'. The atmosphere is exposed, chambers 1 and 1' are opened, and the adhesively sealed laminated member 3 is taken out to complete the work.

These working condition processes are shown in FIG.

In FIG. 3, tl is the time to start applying pressure, t2 is the time to reach the degree of vacuum, t3 is the time to apply the heater, t4 is the time to complete the first stage pressurization, t5 is the time to reach temperature, t6 is the time to start cooling,
t7 indicates the pressure release time, and t[l indicates the adhesion completion time. Further, t represents the second stage pressurization completion time, Po represents the atmospheric pressure, P□ represents the ultimate degree of vacuum, and P2 represents the first stage degree of vacuum.

In the cycle diagram shown in Figure 3, the bottom row shows the temperature of the laminated member;
The middle row shows the pressure in the chamber 12', and the top row shows changes in the pressure in the chamber 12. What is important here is that the solar cell element located in the middle of the laminated member 3 does not crack due to adhesive pressure. Therefore, the way this adhesive pressure is applied determines whether cracking occurs or not. During this work process, the adhesive pressure is separated into P2 and Po, and the rate of increase in the adhesive pressure can be varied. When EVA is actually used as a resin sheet and a polycrystalline solar cell element is adhesively sealed, T is 150°C, P2 of the chamber 12 is 3 atm, and the pressure rise time (t4 to 11
), 10-15 minutes was the condition under which no cracking of the device occurred.

In the example, variable leak valves are used in two stages as a means of increasing the rate of increase in adhesive pressure, but if more fine pressure control is required, they may be provided in multiple stages, or if it is desired to adjust the pressure itself. If there are multiple stages, the adhesive pressure is determined by the differential pressure between the chambers 12 and 12' and can be easily set by closing the final stage variable leak valve and maintaining the degree of vacuum.

〔Effect of the invention〕

As described above, the present invention performs adhesive sealing while adjusting the adhesive pressure, so that it is possible to eliminate cracks, chips, etc. of the element that occur during adhesive sealing. Furthermore, since the chamber is divided into 2') and the adhesive pressure is adjusted based on the pressure difference between the two chambers, the rate of increase in pressure can be controlled, and the generation of bubbles that occur during adhesive sealing can be suppressed. It is effective.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing a stacked structure of solar cells, and FIG. 3 is a diagram showing a cycle of lamination adhesion. In the figure, 1, 1'... chamber, 2... rubber plate, 3... laminated member, 4... heater, 5, 5'...
Water cooling pump, 6-. 7-...Exhaust pipe, 8, 9, 10.1
σ, 1o", 1o"'...Valve, 12°12'
...Chamber chamber, 13, 13'...Variable leak valve, 14°14'...Resin sheet, 15, 15'...
...Solar cell element, 16...Backing material, 17...Glass plate Patent applicant NEC Corporation Figure 1 11--Rotary pump. /2.12'-------------Nayanbar Room/
3. /3'----------------Variable leter valve Fig. 2 Fig. 3

Claims (1)

[Claims] (1) In an apparatus for laminating and bonding solar cell elements to other members using EVA (ethylene vinyl acetate) or PVB (polyvinyl butyral), the chamber containing the laminated member of the solar cell element is divided into two chambers. The two chambers are connected to a vacuum device through a valve, and one chamber is connected to a variable leak valve through a valve, and the laminated member is applied to a partition member that partitions the inside of the chamber in response to a pressure difference between the two chambers. A laminating adhesive device characterized by using a flexible pressing plate for pressing.