TWI694468B - Conductive paste, electrical module and method for forming electrical module - Google Patents

Abstract

A conductive paste including an adhesive and conductive particles, wherein the variation coefficient of diameter of the conductive particles is 25% or less. The average of diameter of the conductive particles is preferably 10 micrometers or more and 500 micrometers or less.

An electrical module wherein a first electrode and a second electrode are bonded to each other through a conductive material formed from the conductive paste, while being partitioned into a plurality of cells, and adjacent ones of the cells are electrically connected with each other.

Description

Conductive paste, electrical module and manufacturing method of electrical module

The invention relates to a conductive paste, an electrical module and a manufacturing method of the electrical module. This case is based on Japanese Patent Application No. 2015-042662 filed in Japan on March 4, 2015 and claims priority, and the contents are incorporated herein by reference.

In recent years, solar cells have attracted attention as clean energy generators, and the development of silicon-based solar cells and dye-sensitized solar cells has continued to advance. Dye-sensitized solar cells have high photoelectric conversion efficiency and are easily mass-produced at a low price, so their structure and manufacturing methods have been extensively studied.

In an electrical module that needs to be sealed represented by the above dye-sensitized solar cell, when a plurality of battery cells are fabricated side by side in the same plane, for example, between adjacent battery cells, the upper electrode of the first battery cell and the The lower electrode of the second battery cell is electrically connected, and the electrolyte and other elements are sealed between the electrodes. For this reason, it has a structure of "sealing material/conducting material (such as lead wire, conductive paste, etc.)/sealing material".

For example, Patent Document 1 discloses that photoelectric cells are arranged side by side in the same plane A photoelectric conversion module of a conversion element. The photoelectric conversion element includes a transparent electrode, a counter electrode, and a sealed insulating portion that seals and insulates the electrodes. In this photoelectric conversion module, in order to electrically connect adjacent photoelectric conversion elements to each other, a part of the transparent electrode member of the first photoelectric conversion element and a part of the opposite electrode member of the second photoelectric conversion element are opposed, and Conductive materials are arranged in between. Thereby, a series structure between a plurality of battery cells is formed.

However, the photoelectric conversion module described in Patent Document 1 uses a metal wire or the like as a conductive material, so there is a problem that it is difficult to cut off the conduction when the battery cell is cut by laser or ultrasonic fusion, etc. It takes time and effort to cut off the battery and battery unit. As a method for solving this problem, there is known a method for obtaining electrical connection by using a conductive paste having a conductive filler in an adhesive.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-357897

However, in the photoelectric conversion module described in Patent Document 1, the conductive paste does not have sufficient conductivity to ensure the electrical connection of the photoelectric conversion elements, so there is a problem that the quality of the electrical module using the conductive paste is difficult to stabilize.

The present invention was made in view of the above circumstances, and provides a conductive paste that can ensure the ease of cutting and stability of quality, and an electrical module including a conductive material formed by the conductive paste.

The conductive paste of the present invention is characterized by containing an adhesive, and a plurality of conductive particles that enable conduction between electrodes, and the coefficient of variation of the diameter of the conductive particles is 25% or less.

Here, the coefficient of variation is expressed as the following formula (1).

In addition, as a method of measuring the average particle diameter used to calculate the coefficient of variation of the diameter of the conductive particles, for example, a method of observing the conductive particles with a microscope and converting the results measured with a vernier caliper (Nonius), etc., The image analysis method, Coulter method, centrifugal precipitation method, laser analysis scattering method, etc. are not particularly limited.

When the coefficient of variation of the diameter of the conductive particles is 25% or less, the diameter of the conductive particles becomes substantially uniform. For example, when the conductive paste of the present invention is arranged between the electrodes constituting the electrical module, the conductive particles are dispersed in the extending direction of the electrodes. Furthermore, by flattening the substrate provided with the electrodes, etc., the conductive particles are easily arranged on the same surface (that is, one surface of the electrode) in a single layer. Therefore, when a conductive material obtained by curing a conductive paste is disposed between electrodes, conductive particles are interposed in a single (ie, single layer) gap in the thickness direction of the electrodes. Thereby, only the adhesive part between the conductive particles in the electrode extension direction is relatively soft and easily cut. When it is cut, it is easy to obtain a contact between the electrodes in the thickness direction between the electrodes, and the electrodes are easily connected to each other. In addition, the thickness dimension between the electrodes is kept substantially constant.

In the conductive paste of the present invention, the average particle diameter of the conductive particles is preferably 10 μm or more and 500 μm or less.

According to the above configuration, when the conductive paste is arranged between the electrodes of the electrical module, the thickness between the electrodes can be appropriately set.

The electrical module of the present invention is characterized in that the first electrode and the second electrode are bonded in a state where the conductive material formed by the conductive paste is divided into a plurality of battery cells, and the plurality of adjacent battery cells are electrically connection.

According to the above configuration, better conduction between the electrodes of the electrical module can be achieved, and the distance between the electrodes of the electrical module can be easily kept fixed.

In the electrical module of the present invention, it is preferable that in the conductive particles, the ratio of the number of conductive particles in contact with both the first electrode and the second electrode is 50% or more.

According to the above configuration, the number of contact points between the electrode and the conductive particles can be ensured to achieve a good conduction, and the contact between the electrodes in the thickness direction between the electrodes can be easily obtained. As a result, the electrodes of the electrical module are easily connected to each other.

In the electrical module of the present invention, it is preferable that the number of conductive particles per unit area of the first electrode or the second electrode that is in contact with both the first electrode and the second electrode is 20 /1mm ² or more.

According to the above configuration, the number of contact points between the electrode and the conductive particles per unit area can be ensured to achieve a good conduction, and the contact between the electrodes in the thickness direction between the electrodes can be easily obtained. As a result, the electrodes of the electrical module are easily connected to each other.

In the electrical module of the present invention, the conductive material may further include the following auxiliary conductive material: the diameter of the auxiliary conductive material is smaller than the interval in the thickness direction between the first electrode and the second electrode.

According to the above configuration, the auxiliary conductive substance is disposed between the conductive particles between the electrodes This gap makes it easier to obtain contacts between the electrodes. With this, the conduction between the electrodes is further realized.

In the electrical module of the present invention, the auxiliary conductive substance is preferably in the form of particles or fibers.

According to the above configuration, the auxiliary conductive substance is effectively arranged in the gap between the conductive particles between the electrodes by being in the form of particles or fibers.

In the electrical module of the present invention, the first electrode or the second electrode may also contain a photosensitizing dye.

According to the above configuration, electrons are transferred from the photosensitizing dye stimulated by light irradiation or the like to the first electrode or the second electrode, so it is easy to complete a dye-sensitized electrical module, for example.

The manufacturing method of the electrical module of the present invention is the manufacturing method of the electrical module of the present invention described above, and is characterized by comprising: a first step which makes the first electrode and the second electrode vacant at any distance to face each other, And at least the conductive paste is arranged between the first electrode and the second electrode; and the second step is to make the first electrode and the second electrode close to each other until the distance between them becomes the average particle of the conductive particles Pressing is performed so that the diameter is 70% or more and 90% or less, and the first electrode and the second electrode are bonded together.

According to the above configuration, in the second step, pressing is performed by suppressing the distance between the first electrode and the second electrode to be smaller than the average particle diameter of the conductive particles, so that the first electrode, the second electrode, and the conductive particles become easier The contact can easily and surely obtain the contact between the electrodes and the conductive particles. In this way, the conduction between the electrodes of the electrical module is further achieved.

According to the conductive paste of the present invention, it is easy to electrically cut and can stabilize between electrodes The effect of ground conduction. In addition, according to the electrical module of the present invention, it is possible to easily cut off the conduction paste between the first electrode and the second electrode and stabilize the conduction between the electrodes.

1‧‧‧Electrical module

1A, 1B‧‧‧Dye-sensitized solar cell (electric module)

2‧‧‧The first substrate

6‧‧‧Conducting materials

7‧‧‧Semiconductor electrode (first electrode)

8‧‧‧counter electrode (second electrode)

20‧‧‧conductive particles

21‧‧‧ Adhesive

28‧‧‧Auxiliary conductive particles (auxiliary conductive substance)

C‧‧‧Battery unit

FIG. 1 is a plan view showing an electrical module according to an embodiment of the present invention.

FIG. 2 is a diagram showing an electrical module according to an embodiment of the present invention, and is a cross-sectional view of a part of the cross-section taken along the arrow line B-B shown in FIG. 1.

FIG. 3 is a diagram showing an electrical module according to an embodiment of the present invention, and is a cross-sectional view taken in the direction of the arrow A-A shown in FIG. 1.

FIG. 4 is a diagram showing a modification of the electrical module according to an embodiment of the present invention, and shows the position of the dye-sensitized solar cell in the modification corresponding to the BB line shown in FIG. 1 as viewed in the direction of the arrow Sectional view of a part of the section.

5 is a diagram for explaining a method of manufacturing a dye-sensitized solar cell according to an embodiment of the present invention, and is a cross-sectional view of a bonded substrate.

6 is a diagram for explaining a method of manufacturing a dye-sensitized solar cell according to an embodiment of the present invention, and is a cross-sectional view of another bonded substrate.

7 is a diagram for explaining a method of manufacturing a dye-sensitized solar cell according to an embodiment of the present invention, and is a cross-sectional view showing a state where the bonded substrates are bonded to each other.

8 is a plan view showing the electrical modules of the first to third embodiments.

Hereinafter, with reference to the drawings, the conductive paste and the electric The manufacturing methods of gas modules and electrical modules are described. In addition, the drawings used in the following description are schematic drawings, and the ratios of length, width, and thickness are not limited to the same as the actual ones, and can be appropriately changed. In addition, the materials and the like exemplified in the following description are only examples, and the present invention is not limited to these and the like, but can be implemented with appropriate changes without changing the scope of the gist thereof.

<conducting paste>

The conductive paste of this embodiment contains at least an adhesive and conductive particles. The conduction paste may also be a person whose liquidity is suppressed, or a person with lower liquidity.

The bonding agent is a substance having a function of keeping the electrodes of the electrical module (not shown) at a specific interval and facing each other. The above-mentioned functions of the adhesive can also be expressed by stimulation such as firing, heating, or light irradiation. Examples of such an adhesive include a resin material containing at least one resin of a thermoplastic resin, a thermosetting resin, and an ultraviolet-curable resin, but it is not particularly limited thereto. Examples of the resin materials include vinyl acetate resin emulsion adhesives, ethylene-vinyl acetate copolymer resins, EVA (ethylene-vinyl acetate-vinyl chloride terpolymer) emulsion adhesives, Alpha-olefin (isobutylene-maleic anhydride resin) adhesive, acrylic resin emulsion adhesive, styrene-butadiene rubber emulsion adhesive, vinyl acetate resin solvent adhesive, acrylic resin Solvent based adhesive, vinyl chloride resin based solvent based adhesive, chloroprene rubber based solvent based adhesive, chloroprene rubber based solvent based adhesive adhesive, nitrile rubber based solvent based adhesive, recycled rubber Solvent-based styrene-butadiene rubber (SBR) solvent-based adhesive, urethane resin-based adhesive, silicone resin-based adhesive, modified silicone resin-based adhesive, Epoxy-modified silicone resin adhesive, acrylic resin (second generation of acrylic adhesives: SGA) adhesive, starch adhesive, polymer cement mortar, epoxy Resin mortar, silanized urethane resin adhesive, hot melt adhesive, etc.

In addition, as an adhesive, as long as it has a function of maintaining a state in which the electrodes of the electrical module are arranged at a certain distance and facing each other, an adhesive material having high viscosity can be used. Examples of such an adhesive material include rubber-based, acrylic-based, silicone-based, and urethane-based ones, but it is not particularly limited thereto. Specifically, natural rubber, acrylate copolymer, silicone rubber, urethane resin, etc. may be mentioned.

The conductive particles are substances dispersed in the adhesive so that the electrodes of the electrical module (not shown) can communicate with each other. The conductive particles may themselves have conductivity like metal particles, or may be particles formed of a conductive metal layer at least on the surface, for example.

The shape of the conductive particles is not particularly limited as long as it functions as a spacer when disposed between the electrodes. From the viewpoint of having a smaller inner resistance while having the largest inner volume, the conductive particles are preferably spherical. Examples of shapes other than the spherical shape of the conductive particles include elliptical shapes, cubic shapes, and polygonal shapes.

The diameter of the conductive particles is formed substantially uniformly. That is, the coefficient of variation of the diameter dimension of the conductive particles defined by the above formula (1) is 25% or less, preferably 15% or less, and more preferably 8% or less. The average particle diameter of the conductive particles is preferably 3 μm or more and 500 μm or less, more preferably 10 μm or more and 250 μm or less, and still more preferably 50 μm or more and 100 μm or less.

Furthermore, in the case where a conductive substance is contained in addition to the above conductive particles, the conductive particles having an average particle diameter within the above-mentioned range contain 1% by mass or more in the plurality of conductive substances contained in the conductive paste, preferably 10 It is more than 40% by weight, more preferably 40% by weight or more, and further preferably 70% by weight or more. By this, it is easy to keep the distance between the electrodes where the conductive materials are arranged to be fixed.

Examples of the conductive particles include metal particles such as gold, silver, copper, chromium, titanium, platinum, nickel, tin, zinc, lead, tungsten, iron, and aluminum. In addition, particles made of compounds containing these metals, particles made of conductive resin, or carbon-based particles such as carbon black can be cited. Furthermore, resin particles coated with a conductive metal such as electroless nickel can be cited.

The conductive particles are particularly preferably those containing flexible resin particles and a conductive metal layer covering the surface of the resin particles (hereinafter, referred to as "resin core conductive particles"). In the case of using resin core conductive particles, in particular, the electrical module can be manufactured by the manufacturing method of the present invention described below, thereby ensuring extremely stable conduction between the electrodes.

Examples of the resin for forming the resin particles of the resin core conductive particles include polyolefin resin, acrylic resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, Saturated polyester resin, polyethylene terephthalate, poly lanthanum, polyphenylene ether, polyacetal, polyimide, polyimide amide imine, polyether ether ketone, polyether lanthanum, etc. Since the hardness of the resin particles can be easily controlled in a preferable range, the resin used to form the resin particles is preferably a polymerized by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group Thing. In addition, as the conductive metal layer, a nickel layer, a palladium layer, a copper layer or a gold layer is preferred, a nickel layer or a gold layer is more preferred, and a copper layer is more preferred.

The thickness of the conductive metal layer is preferably 10 nm or more and 200 μm or less, more preferably 200 nm or more and 100 μm or less, and particularly preferably 1 μm or more and 30 μm or less.

For the detailed structure or preparation method of the resin core conductive particles, refer to International Publication No. 2011/132658.

In the conductive paste of the present embodiment, from the viewpoint of appropriately dispersing the conductive particles in the conductive paste, it is preferable that the conductive particles contain 99.9% relative to the conductive particles of 0.1% by mass to 70% by mass. Adhesive of mass% to 30 mass%. With such a mass ratio, as described above, the conductive particles are appropriately dispersed in the conductive paste, and the hardness of the conductive paste becomes such that it is easy to arrange on the electrode. In addition, the conductive paste contains conductive particles to the extent that the conductive particles suitable for achieving stable conduction between the electrodes can be maintained and the conductive paste can be easily insulated or cut by ultrasonic waves or the like. In this way, the adhesive has the function of maintaining the dispersed state of the conductive particles in addition to the above functions and the like.

The conductive paste of this embodiment preferably contains an auxiliary conductive material in addition to the adhesive and conductive particles. For example, if the auxiliary conductive substance is in the form of particles, when it is disposed between the electrodes as a conductive material, it has a diameter dimension smaller than the interval in the thickness direction between the electrodes.

In order to allow the auxiliary conductive substance to intersect the gap of the conductive particles in the conductive material, the average particle size of the auxiliary conductive substance is preferably, for example, 80% or less relative to the average particle size of the conductive particles, more preferably 50% or less, and further It is preferably below 30%. With this, the above object is achieved, the conductivity of the conductive material is further improved, and thereby the electrical conductivity between the electrodes is stably conducted.

The auxiliary conductive material may be any one that has conductivity and does not hinder the conductivity of the conductive particles, and may include a particle-shaped or fiber-shaped auxiliary conductive material having a smaller diameter than the conductive particles.

Examples of materials for the auxiliary conductive substance include gold, silver, copper, chromium, titanium, platinum, nickel, tin, zinc, lead, tungsten, iron, aluminum, and other metals, compounds containing these metals, conductive resins, or Carbon black is made of carbon materials. It may be the same as the above conductive particles.

When the auxiliary conductive substance is fibrous, the case where the fiber diameter is 45% or less relative to the particle diameter of the conductive particles can be exemplified. It is more preferably 30% or less, and still more preferably 15% or less. As the fiber length of the conductive fiber, an aspect ratio of 2 to 500 can be exemplified. The fiber diameter and aspect ratio can be adjusted appropriately in a manner that does not hinder the conductivity of the conductive particles.

The shape or size of the auxiliary conductive material may be uniform or non-uniform, and is not particularly limited.

Furthermore, an organic solvent may be added to the conductive paste of this embodiment. The organic solvent is an auxiliary medium for maintaining the dispersed state of the conductive particles or binder resin. Examples of such organic solvents include water, ethyl acetate, ester-based, alcohol-based and ketone-based solvents, tetrahydrofuran, hexane, and aromatic solvents, but are not particularly limited thereto.

The above-mentioned conductive paste contains a substantially uniform amount of conductive particles in the adhesive, so when it is arranged between the electrodes, it is easy to flatten the conductive particles by pressure or the like to arrange the conductive particles in a single layer on the same surface . Therefore, when the conductive paste is disposed between the electrodes of the electrical module as a conductive material, the conductive particles intersect with each other in the thickness direction (ie, a single layer) between the electrodes. The conductive materials between each other are easily cut off. In addition, the electrodes are easily connected to each other. Therefore, it is easy to obtain contacts between the electrodes, and it is easy to keep the distance between the electrodes fixed.

Furthermore, in the present embodiment, a conductive paste or conductive material in which conductive particles are directly dispersed in an adhesive is exemplified and described, but the conductive particles may also be interposed by a suitable auxiliary material (not shown) or a sealing material. It is held indirectly by the adhesive, and these are integrated. Examples of non-conductive materials that can constitute such auxiliary materials include resin materials including at least one of resins such as thermoplastic resins, thermosetting resins, and ultraviolet curing resins, or known fiber materials constituting fibers, cellulose , Polyvinyl alcohol and other materials. As the auxiliary material, in addition to those exemplified above, a well-known sealing material used in electrical modules such as solar cells can also be used.

<Electrical Module>

Next, a dye-sensitized solar cell (electric module) 1A as an example of the electric module 1 of the present embodiment will be described.

Furthermore, the dye-sensitized solar cell 1A will be described below, but the conductive material 6 of this embodiment can be applied to the sealing of a plurality of battery cells C that need to be formed between the first base material 2 and the second base material 4 , And various electrical modules in which the battery cells C, C...., C are electrically connected in series or in parallel. As shown in FIG. 1 or FIG. 2, the dye-sensitized solar cell 1A is formed by a transparent conductive film 3 provided on a first substrate 2 and an opposite conductive film 5 provided on a second substrate 4 via a conductive material 6. Opposite configured electrical modules.

As shown in FIG. 1, the dye-sensitized solar cell 1A includes a first substrate 2, a semiconductor electrode (first electrode) 7, a second substrate 4, a counter electrode (second electrode) 8, an electrolyte 9, and a conductive material 6.

The semiconductor electrode 7 includes a transparent conductive film 3 laminated on the first substrate 2 and a porous semiconductor layer 10 stacked on the transparent conductive film 3.

A well-known photosensitizing dye (not shown) is adsorbed on the surface of the semiconductor layer 10 including the porous interior that the electrolyte 9 contacts.

The counter electrode 8 includes a counter conductive film 5 laminated on the second substrate 4 and a catalyst layer 11 stacked on the counter conductive film 5.

The conducting material 6 is disposed between a plurality of semiconductor layers 10 extending parallel to each other in one direction.

Regarding the conductive material 6, as described above, the conductive particles 20 contained in the conductive material 6 are formed into a substantially uniform size, and the conductive particles 20 are flattened or pressurized during the coating or disposition of the conductive material 6 to make the conductive particles 20 It is easy to arrange in a single layer without overlapping in the thickness direction. That is, as shown in FIG. 3, the conductive particles 20 of the conductive material 6 are easily arranged between the transparent conductive film 3 and the opposite conductive film 5 in a single layer in the thickness direction by leveling operations such as pressing.

In the above configuration, among the conductive particles 20 of the conductive material 6, the ratio of the number of conductive particles 20 that are in contact with both the transparent conductive film 3 of the semiconductor electrode 7 and the opposite conductive film 5 of the opposite electrode 8 is 50% The above is preferably 60% or more, and more preferably 68% or more.

In addition, in order to achieve good conduction of the dye-sensitized solar cell 1A, the conductive particles 20 that are in contact with both the semiconductor electrode 7 and the opposite electrode 8 are important. the number of the conductive particles 20 contact both of the sum of 20 / 1mm ² or more, preferably 30 / 1mm ² or more, more preferably 50 / 1mm ² or more.

As shown in FIG. 1 or FIG. 2, sealing materials 12 and 12 are arranged on both sides of the conducting material 6.

Between the electrodes (ie, between the transparent conductive film 3 and the opposite conductive film 5), the conductive material 6 and the sealing material 12 are bonded. On the other hand, in a direction crossing the above-mentioned one direction (the extending direction of the conducting material 6), insulation and adhesion are performed by means such as ultrasonic fusion (hereinafter, the insulated portion is referred to as "insulation portion 13"). In this way, the battery cells C having the semiconductor layer 10 are sealed in a liquid-tight manner. In addition, the conductive particles 20 contained in the conductive material 6 form a gap in the thickness direction between the semiconductor electrode 7 and the counter electrode 8, and the electrolyte 9 is sealed in the gap.

In the dye-sensitized solar cell 1A, the conductive material 6 directly contacts the transparent conductive film 3 constituting the semiconductor electrode 7 and the counter electrode 8. At specific portions of the transparent conductive film 3 and the opposing conductive film 5, a plurality of insulating pattern portions 25 are provided by laser irradiation or the like.

The transparent conductive film 3 and the opposing conductive film 5 of adjacent battery cells C and C are divided into a plurality of patterns by the pattern portion 25 to form a pattern of the plurality of transparent conductive films 3 and the opposing conductive film 5. In each divided battery cell C, the opposite conductive film 5 constituting the opposite electrode 8 of the first battery cell C1 and the semiconductor power constituting the second battery cell C2 adjacent to the first battery cell C1 The transparent conductive film 3 of the pole 7 is electrically connected by the conducting material 6. As a result, the first battery cell C1 and the second battery cell C2 are connected in series.

The materials of the first substrate 2 and the second substrate 4 constituting the semiconductor electrode 7 and the counter electrode 8 are not particularly limited, and examples thereof include insulators such as glass and resin, semiconductors, and metals. Examples of the resin include poly(meth)acrylate, polycarbonate, polyester, polyimide, polystyrene, polyvinyl chloride, and polyamide. From the viewpoint of manufacturing a thinner and lighter flexible dye-sensitized solar cell 1A, the substrate is preferably made of transparent resin, more preferably polyethylene terephthalate (PET) film or polynaphthalene Ethylene formate (PEN) membrane.

The types of the transparent conductive film 3 and the counter conductive film 5 are not particularly limited, and a conductive film used in a known dye-sensitized solar cell can be applied, and for example, a thin film composed of a metal oxide can be cited. Examples of the metal oxides include tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (ATO), indium oxide/zinc oxide (IZO), and gallium-doped zinc oxide (GZO). .

The semiconductor layer 10 is made of a material capable of receiving electrons from the adsorbed photosensitizing dye, and is generally preferably porous. The material constituting the semiconductor layer 10 is not particularly limited, and a well-known material of the semiconductor layer 10 can be applied, and examples thereof include metal oxide semiconductors such as titanium oxide, zinc oxide, and tin oxide.

The photosensitizing dye carried in the semiconductor layer 10 is not particularly limited, and examples thereof include known dyes such as organic dyes and metal complex dyes. Examples of the organic dyes include coumarin-based, polyene-based, cyanine-based, semi-cyanine-based, and thiophene-based. As the metal complex dye, for example, ruthenium complex and the like can be preferably used.

The material constituting the catalyst layer 11 is not particularly limited, and known materials can be applied Materials include, for example, carbons such as platinum and nanotubes, and conductive polymers such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT/PSS).

The type of electrolyte 9 is not particularly limited, and an electrolyte used in a known dye-sensitized solar cell can be used. Examples of the redox couple (that is, electrolyte 9) include an electrolytic solution in which iodine and sodium iodide are dissolved in an organic solvent.

The dye-sensitized solar cell 1A described above has the structure of “the conducting material 6 includes a large number of conductive particles 20 to achieve conduction”, and therefore has the following effect: When the battery cell C is formed or subdivided using ultrasonic waves, The conducting material 6 can be easily insulated.

Also, regarding the dye-sensitized solar cell 1A, the conductive particles 20 contained in the conductive material 6 are formed to have a substantially uniform size, so it is easy to arrange a single conductive particle in the thickness direction between the transparent conductive film 3 and the opposite conductive film 5 20. Therefore, the dye-sensitized solar cell 1A has the effect of easily fixing the size between the transparent conductive film 3 and the opposite conductive film 5.

In addition, since the dye-sensitized solar cell 1A can easily make the size between the transparent conductive film 3 and the opposite conductive film 5 substantially constant, there is a single (single layer) conductive particle 20 between the transparent conductive film 3 and the opposite conductive film 5 Moreover, it is easy to realize conduction in the thickness direction, so that it is easy to achieve conduction with each conductive particle 20 reliably.

In addition, the dye-sensitized solar cell 1A can form the distance between the transparent conductive film 3 and the opposite conductive film 5 through the conductive material 6. Therefore, the formation of the gap does not depend on the sealing materials 12 and 12 disposed on both sides of the conductive material 6. Therefore, the dye-sensitized solar cell 1A has the effect of making the width of the sealing materials 12 and 12 disposed on both sides of the conductive material 6 as small as possible, and making the area of the semiconductor layer 10 in the battery cell C as large as possible.

Also, in the dye-sensitized solar cell 1A, the conductive particles 20 and the semiconductor The ratio of the number of conductive particles that the electrode 7 and the counter electrode 8 are in contact with is more than 50%, so the number of contact points between the semiconductor electrode 7 and the counter electrode 8 and the conductive particle 20 can be ensured to achieve dye sensitization The degree of good conduction of the solar cell 1A.

Moreover, in the dye-sensitized solar cell 1A, the number of conductive particles 20 per unit area of the semiconductor electrode 7 and the counter electrode 8 that are in contact with both the semiconductor electrode 7 and the counter electrode 8 is 20/1 mm ² or more, so that the number of contact points between the semiconductor electrode 7 and the counter electrode 8 per unit area and the conductive particles can be ensured to achieve a good conduction of the dye-sensitized solar cell 1A.

Therefore, according to the dye-sensitized solar cell 1A, it is easy to obtain the contact between the electrodes in the thickness direction between the electrodes, so that the electrodes of the dye-sensitized solar cell 1A become easily conductive to each other.

4 is a diagram showing a dye-sensitized solar cell (electric module) 1B as a modification of the dye-sensitized solar cell 1A, and is shown in the dye-sensitized solar cell 1B corresponding to the BB line shown in FIG. A cross-sectional view of a part of the cross-section where the position is observed along the arrow direction. In addition, among the constituent elements of the dye-sensitized solar cell 1B shown in FIG. 4, the same constituent elements as the constituent elements of the dye-sensitized solar cell 1A shown in FIG. 2 are denoted by the same symbols, and descriptions thereof are omitted.

The conductive material 6 of the dye-sensitized solar cell 1B includes auxiliary conductive particles (auxiliary conductive materials) 28 in addition to the adhesive 21 and the conductive particles 20. As shown in FIG. 4, the auxiliary conductive particles 28 have conductivity, and have a diameter smaller than the interval in the thickness direction between the semiconductor electrode 7 and the counter electrode 8. That is, the auxiliary conductive particles 28 are conductive particles that do not have the function of spacers. According to this configuration, in the conductive material 6 between the semiconductor electrode 7 and the counter electrode 8, the auxiliary conductive particles 28 are arranged in the gap between the conductive particles 20, and the gap between the semiconductor electrode 7 and the counter electrode 8 can be more easily obtained contact. Therefore, the semiconductor electrode 7 and the counter electrode 8 can be realized Between the more reliable conduction.

<Manufacturing method of electrical module>

Next, a manufacturing method of the dye-sensitized solar cell 1A (hereinafter, also simply referred to as "manufacturing method") will be exemplified, and an embodiment of the manufacturing method of the electrical module 1 of the present invention will be described.

The manufacturing method of this embodiment is a manufacturing method of a dye-sensitized solar cell 1A (manufacturing method of an electrical module), and includes the following steps: The first step is to free the semiconductor electrode 7 and the counter electrode 8 by an arbitrary distance. Opposite, and at least a conductive paste is placed between the semiconductor electrode 7 and the counter electrode 8; and the second step is to make the semiconductor electrode 7 and the counter electrode 8 close to each other until the distance between them becomes the average particle of the conductive particles 20 Pressing is performed so that the diameter is 70% or more and 90% or less, and the semiconductor electrode 7 and the counter electrode 8 are bonded together. Hereinafter, each step will be specifically described.

[First step]

First, using a known method of manufacturing a dye-sensitized solar cell using a roll-to-roll method, a transparent conductive film 3 is formed on a specific position on a first substrate 2 that is continuously transported in a specific direction P to form a battery cell, Thereafter, the semiconductor layer 10 is formed at a specific position and the sealing material 12 is formed on both sides (that is, around) of the semiconductor layer 10, and then the electrolyte 9 is laminated. Thereby, as shown in FIG. 5, the bonded base material 31 provided with the semiconductor electrode 7 and the sealing material 12 and having the gap S formed at an appropriate position is obtained. In addition, the specific direction P may be set freely in consideration of convenience in manufacturing and the like, and may be set in a direction parallel to the extending direction of the conductive material 6, for example.

Next, using a well-known method of manufacturing a dye-sensitized solar cell, an opposite conductive film 5 is formed on a specific position on the second substrate 4 that is continuously transported in a specific direction P to form a battery cell, and thereafter,位置 formation catalyst layer 11. With this, as shown in FIG. 6, The bonding substrate 32 of the counter electrode 8 is prepared.

Next, as shown in FIG. 7, the gap S (between the first electrode and the second electrode) S of the bonded substrate 31 is filled with a conductive paste containing at least an adhesive and conductive particles 20 from the conductive paste supply part 40 to make a conductive材6. In fact, it may be considered that the sealing material 12, wiring material, etc. will be crushed and diffused in the second step described below, and the conductive paste is filled in a slightly thicker manner than the specific thickness.

[Second step]

Next, as shown in FIG. 8, the semiconductor layer 10 of the bonding base 31 and the catalyst layer 11 of the bonding base 32 face each other, and the bonding base 31 and the bonding base 32 are brought close to each other. It is used to arrange a pair of rollers 41 and 42 along the thickness direction of the bonding substrates 31 and 32 with a certain interval in the thickness direction so that the bonding substrate 31 and the bonding substrate 32 are closer to each other Way. At this time, the distance T between the transparent conductive film 3 of the semiconductor electrode 7 and the opposite conductive film 5 of the opposite electrode 8 is set to 70% or more and 90% or less of the average particle diameter of the conductive particles 20, preferably 75 % Above and 85% below. In addition, it is preferable to appropriately adjust the distance between the pair of rollers 41 and 42 in the vertical direction, the pressing force, and the like so that the distance T between the semiconductor electrode 7 and the counter electrode 8 becomes the above-mentioned condition. In this way, by using a pair of rollers 41 and 42 to press the distance T to be shorter than the average particle diameter of the conductive particles 20, according to the material and elasticity of the conductive particles 20, a part of the conductive particles 20 (ie, the diameter size is greater than The conductive particles 20) at a distance T are crushed.

Ultraviolet rays UV are irradiated from the ultraviolet irradiation portion 46 appropriately arranged with respect to the pressing space w pressed by the pair of rollers 41 and 42 to harden the sealing material 12 made of ultraviolet curing resin, thereby bonding the bonding base 31 and the bonding The substrate 32 is bonded. At this time, the shape of the conductive particles 20 crushed by the pair of rollers 41 and 42 in the pressing space w as described above may be restored. The contact area between the conductor electrode 7 and the counter electrode 8 and the conductive particles 20 is enlarged, and the contact between the semiconductor electrode 7 and the counter electrode 8 and the conductive particles 20 can be formed more reliably. In addition, the dispersion of the conductive particles 20 in the conductive material 6 is stable. In addition, in order to promote the hardening of the sealing material 12, ultraviolet rays may be irradiated again in front of the conveying direction P than the pressing space W.

In addition, in terms of recovering the shape of the conductive particles 20 by elastic deformation and elastic recovery of the conductive particles 20 due to crushing, the conductive particles 20 are preferably made of resin beads (fine particles).

Through the first and second steps described above, the dye-sensitized solar cell 1A shown in FIGS. 1 and 2 is obtained. In addition, the manufacturing method of the dye-sensitized solar cell 1B shown in FIG. 4 is the same as the manufacturing method of the dye-sensitized solar cell 1A described above except that the conductive paste contains the auxiliary conductive material 21.

In the manufacturing method of the electrical module 1 described above, when a conductive paste containing at least an adhesive and conductive particles 20 is disposed between the semiconductor electrode 7 and the counter electrode 8 constituting the electrical module 1, the conductive particles 20 are The semiconductor electrode 7 and the counter electrode 8 are dispersed in the extending direction. Furthermore, the bonding base material 31 having the semiconductor electrode 7 and the bonding base material 32 having the counter electrode 8 are pressed and flattened so as to be flattened and bonded, whereby the conductive particles 20 are easily arranged in a single layer On the same side (ie, one side of the electrode). Therefore, when the conductive material 6 that has reduced the fluidity of the conductive paste is arranged between the electrodes, the conductive particles 20 intersect in a single (ie, single layer) gap S in the thickness direction of the electrodes. Thereby, according to the manufacturing method of the electrical module 1, the electrical module 1 in which only the adhesive or the adhesive between the conductive particles 20 in the extending direction of the electrode is relatively soft and easy to cut.

Also, in the manufacturing method of the electrical module 1, the semiconductor in the pressing space w In the thickness direction between the electrode 7 and the counter electrode 8, the distance T between the transparent conductive film 3 and the counter conductive film 5 is set to 70% or more and 90% or less of the average particle diameter of the conductive particles 20, whereby the transparent conductive The film 3 and the opposite conductive film 5 are pressed against the conductive particles 20. Thereby, the contact between the semiconductor electrode 7 and the counter electrode 8 and the conductive particles 20 can be easily and reliably obtained, and the contact area of the semiconductor electrode 7 and the counter electrode 8 and the conductive particles 20 is ensured to a certain extent, so The electrodes conduct well with each other. Therefore, according to the manufacturing method of the electrical module 1, the electrical conductivity of the electrical module 1 can be reliably maintained, and the quality of the electrical module 1 can be stabilized well. That is, it is possible to obtain the electrical module 1 that can be easily cut electrically, can easily cut the conductive material 6 between the semiconductor electrode 7 and the counter electrode 8, and can conduct highly stable conduction between the electrodes.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to this specific embodiment, and various modifications and changes can be made within the scope of the gist of the present invention described in the scope of patent application.

For example, the conducting material 6 itself may also function as the sealing material 12 and serve as the sealing material 12.

[Example]

Hereinafter, the present invention will be described more specifically with examples and comparative examples, but the present invention is not limited to the following examples.

(First embodiment)

Prepare a conductive film made of PET film with ITO. The size of the conductive film is set to 10 cm in the longitudinal direction and 15 cm in the horizontal direction, and the thickness of the conductive film is set to 100 μm. In addition, insulation processing is performed within 8.3 cm from the end (see FIG. 8).

Next, as shown in FIG. 8, a sealing material having a linear shape and a width dimension of 1.5 mm in plan view is arranged at intervals and in the vicinity of the portion where insulation processing is performed.

Next, Micropearl (registered trademark) AU-250 whose surface was gold-plated was mixed with 4.5 g of epoxy resin as an adhesive and 4.5 g of phenol resin as conductive particles to make a conductive paste. The average particle diameter of the conductive particles is 50 μm, and the coefficient of variation of the diameter of the conductive particles is 6%. In addition, the conductive particles were mixed with the epoxy resin and the phenol resin so as to contain 10% by mass in the conductive paste.

Next, as shown in FIG. 8, the above-mentioned conductive paste is applied between the two sealing materials. Thereafter, a counter electrode having the same size as the conductive film is prepared and bonded to the conductive film, and the conductive paste is cured by thermal curing at 140°C to form the conductive paste as a conductive material, thereby manufacturing an electrical module.

After heat curing, the resistance value between the conductive film and the counter electrode was measured using a testing machine, and as a result, a resistance value approximately equal to that of the copper wire and the silver paste was obtained. That is, as described above, it was confirmed that the electrical module of this embodiment can ensure the same conductivity as the copper wire.

Then, as shown in FIG. 8, the electrical module of the first embodiment is separated (cut) by using an ultrasonic fusion machine in the direction in which the conductive material is transverse. Thereafter, the continuity of the battery cells adjacent to each other on the diagonal line (X line shown in FIG. 8) was confirmed with a testing machine. As a result, the continuity was not confirmed, and it was confirmed that it was cut off. When this operation was performed, no extra time was spent in order to cut the conductive material.

(Second embodiment)

An electrical module was formed in the same manner as in the first embodiment except that silver particles were used as conductive particles instead of Micropearl (registered trademark) AU-250 that had been gold-plated. In addition, the coefficient of variation of the average particle diameter and diameter of the silver particles is also set to be the same as that of the first embodiment.

After the thermal curing of the conductive paste, the resistance value between the conductive film and the counter electrode was measured using a testing machine. As a result, the resistance was almost the same as that of the copper wire and the silver paste as in the first embodiment. value.

In addition, in the same manner as the first embodiment, after separating the electrical module of the second embodiment using an ultrasonic fusion machine in the cross-sectional direction of the adhesive and the conductive material, confirm with the test machine on the diagonal ( The continuity of adjacent battery cells on the X line shown in FIG. 8 was not confirmed, and as a result, it was confirmed that it was cut off. When this operation was performed, no extra time was spent in order to cut the conductive material.

(Third embodiment)

Electroless nickel plating was performed on the surface of Micropearl (registered trademark) AU-250 used in the first embodiment as conductive particles. As a result, conductive particles having an average particle diameter of 63 μm and a coefficient of variation in diameter size of 23% were obtained. Except for this, the electrical module is formed in the same manner as the first embodiment.

After the thermal curing of the conductive paste, the resistance value between the conductive film and the counter electrode was measured using a testing machine. As a result, the resistance value was almost the same as that of the copper wire and the silver paste in the same manner as in the first embodiment.

In addition, in the same manner as the first embodiment, after separating the electrical module of the third embodiment using an ultrasonic fusion machine in the cross-sectional direction of the adhesive and the conductive material, confirm the diagonal line with the testing machine ( The continuity of adjacent battery cells on the X line shown in FIG. 8 was not confirmed, and as a result, it was confirmed that it was cut off. When this operation was performed, no extra time was spent in order to cut the conductive material.

(Comparative example)

Use conductive tape (manufacturer: Teraoka Manufacturing Co., Ltd.) with a width of 1.5 mm and a thickness of 60 μm as the conductive material, and install it along the extending direction of the sealant. The electrical module is formed in the same manner as the first embodiment.

Also, in the same manner as the first embodiment, after separating the electrical modules of the comparative example in the transverse direction of the conductive material by an ultrasonic fusion machine, confirm with the test machine on the diagonal (shown in Figure 8 (X line) The continuity of the battery cells adjacent to each other. As a result, the continuity was confirmed without being cut off. When performing this operation, in order to cut off the conductive material, it takes about three times the time required by the first to third embodiments. Furthermore, in order to finally cut the conductive material, other steps have to be performed.

Through the above-described first and third embodiments and the comparative examples, it is confirmed that according to the conductive paste and conductive material of the present embodiment, the rigidity of the conductive material becomes lower than before, and the conductive material becomes It is softer than before, and the conductive material and the electrical module using the conductive material can be easily cut by laser or ultrasonic fusion.

1A‧‧‧Dye-sensitized solar cell (electric module)

2‧‧‧The first substrate

3‧‧‧Transparent conductive film

4‧‧‧Second substrate

5‧‧‧ Opposite conductive film

6‧‧‧Conducting materials

7‧‧‧Semiconductor electrode (first electrode)

8‧‧‧counter electrode (second electrode)

9‧‧‧Electrolyte

10‧‧‧semiconductor layer

11‧‧‧catalyst layer

12‧‧‧Sealing material

20‧‧‧conductive particles

21‧‧‧ Adhesive

25‧‧‧ Pattern Department

C‧‧‧Battery unit

C1‧‧‧ First battery unit

C2‧‧‧Second battery unit

Claims (9)

An electrical module in which a first electrode and a second electrode are bonded in a state where a conductive material formed by a conductive paste is divided into a plurality of battery cells, and the adjacent plurality of battery cells are electrically connected; the conductive paste Contains an adhesive and conductive particles that enable conduction between the electrodes. The coefficient of variation of the diameter of the conductive particles is 25% or less. Among the conductive particles, the conductive particles are in contact with both the first electrode and the second electrode The number of particles is more than 50%. For example, in the electrical module of claim 1, the average particle diameter of the conductive particles is 3 μm or more and 500 μm or less. The electrical module as claimed in item 1 of the patent application, wherein the number of conductive particles per unit area of the first electrode or the second electrode that is in contact with both the first electrode and the second electrode is 20 pcs/1mm ² or more. The electrical module according to any one of the patent application items 1 to 3, wherein the conductive material further contains the following auxiliary conductive material: the auxiliary conductive material has a diameter smaller than that between the first electrode and the second electrode The interval in the thickness direction. For example, in the electrical module of claim 4, the auxiliary conductive material is in the form of particles or fibers. The electrical module according to any one of claims 1 to 3, wherein the first electrode or the second electrode contains a photosensitizing dye. An electrical module as claimed in item 4 of the patent application, wherein the first electrode or the second electrode contains a photosensitizing dye. An electrical module as claimed in item 5 of the patent application, wherein the first electrode or the second electrode contains a photosensitizing dye. A method for manufacturing an electrical module, which is a method for manufacturing an electrical module according to any one of the items 1 to 8 of the patent application, comprising: a first step which makes the first electrode and the second electrode vacant Facing at any distance, and at least the conductive paste is arranged between the first electrode and the second electrode; and the second step is to bring the first electrode and the second electrode closer to each other until the distance between them becomes The conductive particles are pressed so as to be 70% or more and 90% or less of the average particle diameter, and the first electrode and the second electrode are bonded together.

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