JP5634308B2 - Heat sealing device - Google Patents

Description

  The present invention relates to a sealing device that encloses an object to be sealed between upper and lower sheet materials, and is not particularly limited. For example, a sealing layer is provided between upper and lower electrodes in a solar cell, an organic EL element, or the like. A liquid electrolyte, a pseudo solid electrolyte, a solid electrolyte, or an organic light emitter is sealed in a closed space formed by joining these upper and lower electrodes and a sealing layer, and a flexible solar cell, organic EL element, etc. The present invention relates to a heat sealing apparatus suitable for manufacturing the cell structure.

  For example, when producing a dye-sensitized solar cell as a flexible solar cell, a working layer (lower sheet material) having a semiconductor layer and a counter electrode (upper sheet material) having a catalyst layer are joined by a sealing layer. A cell structure of a solar cell is formed by enclosing an electrolyte layer in a closed space formed by the working electrode, the counter electrode, and the sealing layer. And as a sealing material used for forming the sealing layer, an epoxy resin adhesive, an ionomer resin adhesive, or the like has been used. However, in recent years, it is melted by heating to a predetermined temperature. Sealing material made of thermoplastic resin such as polyester resin, polyethylene resin, modified polyethylene resin, polypropylene resin, modified polypropylene resin, etc., and epoxy to be cured by heating to a predetermined temperature Sealing materials made of thermosetting resin such as resin, ionomer resin, isobutylene resin, and silicone resin have come to be used, and these sealing materials are sandwiched between the working electrode and the counter electrode. Alternatively, it can be melted by heating through a counter electrode, or thermoset, and thereby between the working electrode and the counter electrode. Heating the joining operation of the sealing material forming the sealing layer is performed (see Patent Documents 1 to 5).

  A sealing material made of a thermoplastic resin used for such a purpose usually has a melting point of about 90 to 150 ° C., and the sealing material is used to heat and melt the sealing material via a working electrode or a counter electrode. It is necessary to heat at a temperature of about 100 to 200 ° C. higher than the melting point, and it is also necessary to heat to the curing temperature of the thermosetting resin used in the sealing material made of thermosetting resin. In order to continuously perform the heat bonding operation of the material, it is necessary to increase the heat capacity of the heating means for heating the sealing material in order to minimize the temperature drop of the heating means when the sealing material is heated and melted. is there.

  In addition, the working electrode constituting the dye-sensitized solar cell is usually formed by laminating a transparent conductive film on a transparent substrate, laminating a semiconductor layer on the transparent conductive film, and further photosensitizing the semiconductor layer. The counter electrode has a structure in which a dye layer is supported, and the counter electrode has a structure in which a catalyst layer is laminated on a counter electrode substrate.Furthermore, a sealing material is arranged in advance at a predetermined position on the working electrode side, In the case where a predetermined electrolyte is injected into the region surrounded by the sealing material to form an electrolyte layer, and then a closed space of the electrolyte layer is formed by the sealing material with the counter electrode facing the working electrode, the sealing material In the heating and bonding operation, an electrolyte layer is present near the seal material.

  However, the transparent substrate, transparent conductive film, semiconductor layer and photosensitizing dye constituting the working electrode of the dye-sensitized solar cell, the counter substrate and catalyst layer constituting the counter electrode, and the electrolyte layer are not necessarily heat resistant. In addition to those that are excellent in performance, the performance may deteriorate or the function may be lost when exposed to high temperatures for long periods of time. In addition, it is desired that only the portion in contact with the counter electrode is locally heated and the influence of heat is blocked as much as possible in the other portions.

  Moreover, in the case of forming such a cell structure of a dye-sensitized solar cell, the working electrode and the counter electrode are formed thin in order to ensure flexibility, and deformation and wrinkles are likely to occur. When a sealing layer is used to join between a counter electrode and a counter electrode, it is usually necessary to strictly align the two. How about the working electrode and counter electrode that are prone to thin deformation and wrinkles? There is another problem of performing accurate alignment.

JP 2005-213,470 Japanese Patent No. 4,504,457 JP 2008-186,763 A JP 2009-283,228 JP 2011-034,726

  Therefore, the present inventors sandwiched an object to be sealed that is relatively poor in heat resistance between the upper sheet material and the lower sheet material, and these upper sheet material and lower sheet material on the outer periphery of the object to be sealed. To form a ring-shaped sealing part that encloses the object to be sealed, and encloses the object to be sealed in a closed space formed by the upper sheet material, the lower sheet material, and the annular sealing part. In doing so, it is necessary to accurately align the upper sheet material and the lower sheet material, which are likely to be deformed or wrinkled, and how to affect the sealed object to be sealed. As a result of diligent examination as to whether heat bonding is performed accurately without giving, a heating means having an annular heating portion according to the shape and size of the annular sealing portion is used, and a work piece is placed inside the annular heating portion. Electrostatic chuck having a heat insulating layer on the opposite side The above-mentioned object is achieved by arranging and fixing at least the upper sheet material by this electrostatic chuck and cutting off part of the heat conduction from the heating means to the object to be sealed at the time of heat bonding. The present invention has been completed by finding out what can be done.

  Therefore, the object of the present invention is to sandwich the object to be sealed between the upper sheet material and the lower sheet material, and to heat the upper sheet material and the lower sheet material outside the outer periphery of the object to be sealed. When encapsulating the object to be sealed in the closed space formed between the upper sheet material and the lower sheet material by bonding, the alignment between the upper sheet material and the lower sheet material is accurately performed. In addition, an object of the present invention is to provide a heat sealing apparatus that can reduce as much as possible the influence of heat during heat bonding on an object to be sealed enclosed in the closed space.

  That is, the present invention includes a heating means having an annular heating portion, sandwiching the object to be sealed between the upper sheet material and the lower sheet material, and annular heating of the heating means outside the outer peripheral portion of the object to be sealed. The upper sheet material and the lower sheet material are heated and joined by a portion to form an annular sealing portion, and the sealed portion is formed in a closed space formed by the upper sheet material, the lower sheet material, and the annular sealing portion. A heating and sealing device that encloses a stationary object, inside the annular heating portion of the heating means, an internal electrode layer, and a dielectric layer that is laminated on the work side of the internal electrode layer and covers the work side An electrostatic chuck having a heat insulating layer laminated on the side opposite to the work side of the internal electrode layer is disposed, and the annular sealing portion is formed by heat bonding between the upper sheet material and the lower sheet material. When forming the dielectric of the electrostatic chuck Is fixed by suction at least the upper sheet material by a layer, which is heated sealing apparatus characterized by blocking a portion of the heat conduction to the sealing material from the heating means by heat insulating layer.

  In the present invention, the annular heating portion of the heating means has a shape and size according to the shape and size of the annular sealing portion formed between the upper sheet material and the lower sheet material, The shape can be an annular shape, an elliptical shape, a triangular shape, a quadrangular shape, a polygonal shape, etc., and the size of the electrostatic chuck can be arranged on the inner side if it can be manufactured. Well, not particularly limited. Moreover, about this cyclic | annular heating part, a heating part should just be formed cyclically | annularly, or may be arrange | positioned cyclically | annularly, and may be endless cyclic | annular or may be divided | segmented into plurality.

  In addition, the heating means of the present invention may be composed of only one annular heating part, or may be composed of two or more annular heating parts. When manufacturing flexible solar cells such as dye-sensitized solar cells arranged in one direction or left and right front-rear directions, a plurality of closed spaces can be formed simultaneously between the upper sheet material and the lower sheet material. For example, it may be configured by a plurality of rectangular annular heating portions arranged in a strip shape in one direction or in a lattice shape in the left-right front-rear direction.

  In the present invention, the upper sheet material and the lower sheet material may be directly heat-bonded to each other when the annular sealing portion is formed therebetween, and the upper sheet material and the lower sheet material It may be heat-bonded via an annular seal member disposed therebetween, and is appropriately selected according to the material of the upper sheet material and / or the lower sheet material. When the upper sheet material and the lower sheet material are directly heat-bonded to each other, the materials of the upper sheet material and the lower sheet material are those having heat sealing properties, and through an annular seal member In the case of heat bonding, an annular seal member conforming to the shape and size of the annular sealing portion formed between the upper sheet material and the lower sheet material is used.

  Further, in the present invention, the electrostatic chuck disposed inside the annular heating portion of the heating means includes an internal electrode layer, a dielectric layer that is laminated on the work side of the internal electrode layer and covers the work side, The internal electrode layer has a heat insulating layer laminated on the side opposite to the work side, and a conventionally known electrostatic chuck structure can be used as it is except for the heat insulating layer. By laminating the heat insulating layer on the side opposite to the workpiece side of the internal electrode layer, the heat insulating layer functions to protect the internal electrode and the dielectric layer against the heat from the back side of the electrostatic chuck, and electrostatic More flexibility in chuck design. In the present invention, the “workpiece” refers to a workpiece that is directly attracted and positioned by an electrostatic chuck, and is fixed, and at the time of heat bonding by the annular heating portion of the heating means, When the lower sheet material side is not temporarily fixed, the upper sheet material is referred to. When the upper sheet material side and the lower sheet material side are temporarily fixed, both of them are considered.

  In this electrostatic chuck, the performance required for the heat insulating layer varies depending on the use of the heat sealing device, etc., for example, when used for manufacturing flexible solar cells such as dye-sensitized solar cells. Preferably, its thermal conductivity is 0.9 W / (m · ° C.) or less, more preferably 0.5 W / (m · ° C.) or less, and its heat resistance is more preferably a thermal decomposition temperature of 300 ° C. or more. Is preferably 350 ° C. or higher. Specific examples of the heat insulating material having such performance include heat-resistant polyimide resin, ceramics, porous ceramics, etc., and more preferably DuPont. Examples thereof include heat-resistant polyimide (trade names: Vespel SP-1, Vespel SP-3, etc.), heat-resistant polyimide (trade names: MELDIN 7001, MELDIN 7021, etc.) manufactured by Saint-Gobain Co., Ltd., and the like.

  Also, the dielectric layer of the electrostatic chuck is laminated on the work side of the internal electrode layer and directly attracts and fixes the work, so it is preferably formed on a flat surface to match the work surface. As a result, even if the workpiece made of the upper sheet material or the lower sheet material is likely to be deformed or wrinkled, the workpiece is adsorbed and positioned inside the ring that is heated and joined in a ring. Since it is fixed, heat bonding can be performed accurately without causing deformation or wrinkles on the workpiece.

  In the heat sealing apparatus of the present invention, the workpiece is positioned and fixed by the electrostatic chuck, and the heat is shielded against the object to be sealed, so that the sealing is performed between the upper sheet material and the lower sheet material. A closed space formed between the upper sheet material and the lower sheet material by sandwiching a stationary object and joining the upper sheet material and the lower sheet material under heating outside the outer periphery of the sealed object When encapsulating the object to be sealed in, this heat bonding operation can be carried out in the atmosphere, as well as in the vacuum environment and the reduced pressure environment where a vacuum chuck or the like cannot be used. It can be carried out in exactly the same way. For this reason, the heat sealing apparatus of the present invention is also useful in heat bonding performed in such a vacuum environment or a reduced pressure environment, and is suitable for applications such as flexible devices (displays, LEDs, solar cells, etc.), for example. Can be used.

  The heat sealing device of the present invention has a heat insulating layer on the opposite side of the workpiece side inside the annular heating portion for forming an annular sealing portion that surrounds the object to be sealed between the upper sheet material and the lower sheet material. Since the electrostatic chuck having the position is disposed, at least the upper sheet material is attracted and positioned, and fixed, and part of the heat conduction from the heating means to the object to be sealed is cut off during the heat bonding. Even if the workpiece made of the upper sheet material is likely to be deformed or wrinkled, and even if the object to be sealed is relatively poor in heat resistance, An object to be sealed can be accurately and safely sealed in a closed space formed by the lower sheet material and the annular sealing portion.

FIG. 1 is an explanatory view of a heat sealing device for explaining the concept of a heat sealing device for producing a dye-sensitized solar cell according to an example of the present invention.

FIG. 2 is an explanatory diagram of the process a for explaining the heat bonding processes a to e when manufacturing the dye-sensitized solar cell using the heat sealing apparatus of FIG. 1.

FIG. 3 is an explanatory diagram of steps b and d for explaining the heat bonding steps a to e when manufacturing the dye-sensitized solar cell using the heat sealing apparatus of FIG. 1.

FIG. 4 is an explanatory diagram of a process c for explaining the heat bonding processes a to e in manufacturing the dye-sensitized solar cell using the heat sealing apparatus of FIG. 1.

FIG. 5 is an explanatory diagram of a process e for explaining the heat bonding processes a to e when manufacturing a dye-sensitized solar cell using the heat sealing apparatus of FIG. 1.

Hereinafter, based on the Example shown to an accompanying drawing, the heat sealing apparatus for dye-sensitized solar cell manufacture of this invention is demonstrated.
In this heat sealing device, when a dye-sensitized solar cell is manufactured, a sealing layer (square) is formed between a working electrode (lower sheet material) having a semiconductor layer and a counter electrode (upper sheet material) having a catalyst layer. The annular sealing portion), and is responsible for the step of encapsulating the electrolyte layer (sealed object) in the closed space formed by the working electrode, the counter electrode, and the sealing layer. Specifically, Place the sealing layer on the working electrode, then place the electrolyte layer inside the sealing layer by means such as injection or printing, and then heat seal the working electrode on which these sealing layer or electrolyte layer is placed Set the device on the lower stage of the device, and position the counter electrode between the working electrode and the counter electrode so that the counter electrode is opposed to the working electrode set on the lower stage with accurate alignment from above. The sealing layer to be heated is heated from above the counter electrode, and the sealing layer is melted or thermoset. Te joined heated between these working electrode and the counter electrode, whereby an electrolyte layer enclosed in the closed space formed, and forms a cell structure of a solar cell.

〔Example〕
In FIG. 1, the principal part of the heat sealing apparatus for dye-sensitized solar cell manufacture which concerns on the Example of this invention is shown. This heating and sealing device includes a heating means 1 having a square annular heating portion 1a, an electrostatic chuck 2 disposed inside the square annular heating portion 1a of the heating means 1, and the heating means 1 and the electrostatic chuck. 2 and a lower stage 3 arranged opposite to each other, and the heating means 1 is provided with a lifting means (not shown) for moving the heating means in the vertical direction, The electrostatic chuck 2 is provided with a pair of air cylinders 4 for moving the electrostatic chuck 2 in the vertical direction and a power supply line 5 for operating the chuck mechanism of the electrostatic chuck 2.

  In this embodiment, the electrostatic chuck 2 includes an internal electrode layer 2a and a dielectric layer 2b which is laminated on the work side of the internal electrode layer 2a so as to cover the work side and the surface is formed on a flat surface. And a heat insulating layer 2c laminated on the side opposite to the work side of the internal electrode layer 2a, and in a quadrangular shape of a size that can be placed inside the square annular heating portion 1a of the heating means 1. The inner electrode layer 2a made of carbon-based ink or the like is formed on the surface of the heat-insulating layer 2c made of a heat-resistant polyimide plate (trade name: Vespel SP-1 manufactured by DuPont) having a thermal conductivity of 0.35 W / (m · ° C). Is screen-printed, and a dielectric layer 2b such as polyimide ink is further screen-printed thereon and laminated.

The heat joining process ae process at the time of manufacturing a dye-sensitized solar cell using the heat sealing apparatus of this Example is demonstrated.
First, as shown in FIG. 2, a working electrode (lower sheet material) 6 having a semiconductor layer 10 on which a sealing layer (square annular sealing portion) 8 and an electrolyte layer 9 are disposed is lowered by means such as a dedicated transport mechanism. The counter electrode (upper sheet material) 7 having a catalyst layer (not shown) is set at a predetermined position on the side stage 3 and is held by being attracted to the electrostatic chuck 2 waiting above the lower stage 3 (step a). ).

  Next, as shown in FIG. 3, after performing accurate alignment with the working electrode 6 and the counter electrode 7, the air cylinder 4 is operated to lower the electrostatic chuck 2. The counter electrode 7 is placed and fixed on the working electrode 6 while adsorbing 7 (step b).

  After the counter electrode 7 is accurately placed on the working electrode 6 in this manner, the counter electrode 7 is attracted and fixed by the electrostatic chuck 2, and as shown in FIG. The heating means 1 is lowered, the lower end surface of the square annular heating portion 1a is positioned above the sealing layer 8 via the peripheral edge of the counter electrode 7, and is further lowered and held under pressure for a predetermined time. 8 is heated, melted, or thermally cured to join between the peripheral edges of the working electrode 6 and the counter electrode 7 (step c).

  After the heating of the sealing layer 8 by the square annular heating portion 1a of the heating means 1 is finished, as shown in FIG. 3, the heating means 1 is raised by a lifting / lowering means (not shown) (step d), and then in FIG. As shown, the air cylinder 4 is actuated to raise the electrostatic chuck 2 and has a cell structure in which an electrolyte layer 9 is enclosed in a closed space formed by a working electrode 6, a counter electrode 7, and a sealing layer 8. The solar cell is transferred from the lower stage 3 to the next process (e process).

  Therefore, according to the heat sealing apparatus of this embodiment, as shown in FIG. 4, when the sealing layer 8 is heated by the square annular heating part 1a of the heating means 1, the heating means 1 and the working electrode 6 and The heat to the counter electrode 7 is blocked as much as possible by the heat insulating layer 2c of the electrostatic chuck 2, and the heat transferred from the square annular heating portion 1a of the heating means 1 to the working electrode 6 and the counter electrode 7 becomes local. The influence of heat on the electrode 6 and the counter electrode 7 can be minimized.

  Moreover, even if the working electrode 6 and the counter electrode 7 are formed of a material having excellent flexibility, the working electrode 6 is supported on the surface by the lower stage 3, and the counter electrode disposed above the working electrode 6. 7, most of the central portion except the peripheral portion heated and bonded by the sealing layer 8 is adsorbed and fixed by the dielectric layer 2 b of the electrostatic chuck 2, so that the working electrode 6 and the counter electrode 7 are the same. Even if the electrode is easily deformed and easily wrinkled, the working electrode 6 and the counter electrode 7 can be accurately heat-bonded.

  DESCRIPTION OF SYMBOLS 1 ... Heating means, 1a ... Square annular heating part, 2 ... Electrostatic chuck, 2a ... Electrode layer, 2b ... Dielectric layer, 2c ... Heat insulation layer, 3 ... Lower stage, 4 ... Air cylinder, 5 ... Power supply line, 6 ... Working electrode (lower sheet material), 7 ... Counter electrode (upper sheet material), 8 ... Sealing layer, 9 ... Electrolyte layer, 10 ... Semiconductor layer.

Claims (8)

A heating means having an annular heating part is provided, an object to be sealed is sandwiched between an upper sheet material and a lower sheet material, and the upper sheet material is formed by an annular heating part of the heating means outside the outer peripheral part of the object to be sealed. Heating to seal the object to be sealed in a closed space formed by the upper sheet material, the lower sheet material and the annular sealing portion. A sealing device,
Inside the annular heating part of the heating means, an internal electrode layer, a dielectric layer laminated on the work side of the internal electrode layer and covering the work side, and the side opposite to the work side of the internal electrode layer And an electrostatic chuck having a heat insulating layer laminated on the substrate,
When forming the annular sealing portion by heat bonding between the upper sheet material and the lower sheet material, at least the upper sheet material is attracted and fixed by the dielectric layer of the electrostatic chuck, and the heat insulating layer A heat sealing apparatus characterized in that a part of heat conduction from the heating means to an object to be sealed is cut off.   The heat insulating layer of the electrostatic chuck is formed of a heat insulating material having a low thermal conductivity of 0.9 W / (m · ° C) or less and a heat resistance of a thermal decomposition temperature of 300 ° C or more. Heat sealing device.   The heat sealing device according to claim 2, wherein the heat insulating material is a heat resistant polyimide resin or ceramic.   4. The electrostatic seal according to claim 1, wherein a dielectric layer covering the workpiece side of the internal electrode layer is formed on a flat surface, and the workpiece is attracted and fixed on the flat surface. Stop device.   The heat sealing device according to any one of claims 1 to 4, wherein the annular heating portion of the heating means has a square annular shape.   The heat sealing device according to any one of claims 1 to 5, wherein the heating means includes a plurality of annular heating portions.   An annular sealing part is a heat sealing apparatus in any one of Claims 1-6 formed of the annular sealing member arrange | positioned between an upper sheet material and a lower sheet material.   The upper sheet material is a working electrode having a semiconductor layer, the lower sheet material is a counter electrode having a catalyst layer, and the square annular sealing portion that heat-joins between the working electrode and the counter electrode is a sealing layer. A sealed structure formed by the working electrode, the counter electrode, and the sealing layer is an electrolyte layer, and the cell structure of the flexible solar cell is formed by the working electrode, the counter electrode, and the electrolyte layer. The heat sealing apparatus for manufacturing the flexible solar cell of Claim 7 formed.

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