JPH05159877A - Plane electro-optical element - Google Patents

Abstract

PURPOSE:To provide an electro-optical element that is less in water-vapor transmission out of a feeding part and excellent in reliability by installing a separate area in a transparent electrode in the peripheral part of a transparent substrate, and setting it down to a connecting terminal of a back plate to be opposed. CONSTITUTION:An electrically separated area is installed in a transparent electrode 2 in a peripheral part of a transparent substrate 1, setting it down to a back plate terminal 12 being conductively connected to a back plate 5 to be opposed to the electrode 2. In addition, each of leaders 7, 8 or a plate terminal is connected to two transparent electrode terminals 6 and 12 formed in a part of the electrode 2, covering it with a back protective material 10. If so, the protective material 10 and the substrate 1 are airtightly joined to respective plane parts such as a base material surface, each electrode terminal or the plate terminal, etc., so sufficient enough. With this constitution, a joint part with the protective material 10 comes to only a planar part, thus such a reliable element as being excellent in airtightness, and less in water-vapor transmission out of a feeding part is securable in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar electro-optical element such as an electroluminescence element, a liquid crystal display element, a plasma display, etc., which is used for displaying or illuminating a liquid crystal display device or a panel, and more particularly to a terminal for supplying current / voltage thereto The present invention relates to a flat-type electro-optical element having the features described in 1.

[0002]

2. Description of the Related Art Electroluminescence devices, liquid crystal display devices, flat-panel display devices such as plasma displays and electrochromic display devices have a voltage applied between a transparent electrode formed on a transparent substrate and a electrode facing the transparent electrode. Is applied to drive an electroluminescent light-emitting body, a liquid crystal or the like provided between both electrodes to emit light or display.

Supply of current / voltage to each electrode of these electro-optical elements is performed by connecting a feeder line to a lead terminal provided on each electrode.

The electroluminescent light-emitting body provided inside the flat type electro-optical element is rapidly deteriorated by moisture, causing blackening, lowering of brightness, etc., and it is different from general semiconductors such as IC and LSI. Different operating voltage is 10
Since it is as low as 0 V, leakage current may increase due to insulation deterioration. In order to prevent moisture permeation from the atmosphere in which it is used, the back surface protective material covers the electroluminescent light-emitting body and the like to prevent the inside of the element from being directly exposed to the outside air and deteriorated.

[0005]

In the electroluminescence element, the lead wire for the terminal or the power feeding is taken out separately from one transparent electrode of the electroluminescence light emitting body and the back electrode provided on the back surface of the light emitting body. It has been practiced to separately perform the sealing treatment of the takeout points, or to extend the lead wire from the transparent electrode to the vicinity of the back electrode and take out the lead wire from both electrodes from the back surface.

Since the transparent electrode is formed of a transparent conductive oxide formed on a substrate such as glass by vapor deposition, sputtering, etc., the processing of the lead-out portion of the terminal can be performed relatively easily by soldering or the like. Possible, but
The back electrode is formed by forming a dielectric layer on the light emitting body and then forming a thin film on the back surface by a film forming method such as sputtering, applying a paste containing a synthetic resin in which fine metal particles are dispersed, or a foil such as aluminum. Since it is formed, complicated processing is required for taking out the terminals and connecting the lead wires.

FIG. 2 (a) is a plan view in which a part of the back surface protective material of the lead-out portion of the electroluminescence light-emitting element which is a planar electro-optical element is cut out, and FIG. 2 (b) is The sectional view which cut | disconnected FIG.2 (a) by the BB line is shown.

A film of the transparent electrode 2 is formed on the glass substrate 1, and a light emitting layer 3 is formed on the film of the transparent electrode. A dielectric layer 4 is provided on the surface of the light emitting layer opposite to the side facing the transparent electrode, and a back electrode 5 for supplying a voltage to the light emitting layer is formed on the dielectric layer. On the other hand, a transparent electrode terminal 6 is provided on a part of the transparent electrode, and a transparent electrode lead wire 7 is attached by soldering or the like.

Further, since the back electrode is usually made of aluminum foil, a vapor deposition film, or a conductive paste, the back electrode lead wire 8 is attached to the back of the metal foil 9 such as tin, which has good bondability with solder. It is provided on the electrode, and the lead wire is attached to the metal foil with solder or the like.

In order to cover the voltage application portion and prevent the light emitting element from deteriorating due to humidity in the atmosphere, the back surface of the element is covered with a back surface protective material 10 made of a synthetic resin film or a composite film of a synthetic resin film and a metal thin film. The portion of the lead wire that covers the side surface and the side surface of the back surface is further filled with a resin having good adhesiveness by potting to form a fixed portion 11 for fixing the lead wire and absorbing moisture from the lead wire. Prevents deterioration.

However, if it is attempted to sufficiently process the lead-out wire take-out portion, complicated processing such as processing of the lead-out wire is required, and the size of the filling / fixing portion of the potting process with resin becomes large. A large protrusion is formed on the back surface of the electroluminescent element, and when the element is mounted on various devices, a problem in terms of dimensions may occur.

Further, in order to make an electrical connection with the back electrode, a skilled technique is required to securely join the lead wire to the metal foil such as tin mounted on the back electrode by soldering. In addition, when used for a longer period of time, a problem may occur due to the permeation of moisture into the inside of the lead wire from the coating of the wire and the core wire.

[0013]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies on a method of attaching a current supply line to a transparent electrode and a back electrode in a planar electro-optical element such as an electroluminescence element It was thought of.

That is, a part of the peripheral portion of the transparent electrode formed on a transparent substrate such as a glass substrate is electrically separated from the other part to form a back electrode connection terminal, which is also used as a back electrode connection terminal when the back electrode is formed. The back electrode is integrally formed so that a part of the back electrode is in conductive contact. And
Except for the attachment part of the lead wire for the back electrode of the back electrode connection terminal and the attachment part of the lead wire for the transparent electrode terminal, the entire back electrode including the contact part with the back electrode is completely covered with the back surface protective material and then the back electrode Attach a lead wire for power supply to the connection terminal and the transparent electrode terminal formed on the substrate by soldering or adhering with a conductive adhesive, and form a synthetic resin coating (thin potting) whose main purpose is insulation, or A flat plate terminal is joined to the transparent electrode terminal and the back electrode connection terminal with a conductive adhesive, and a back surface protective material is covered and pressure-bonded to the entire back surface.

In the flat type electro-optical element of the present invention, a terminal portion for connecting a lead wire for supplying current / voltage or a flat plate terminal is made of a conductive film provided on the substrate surface, and is attached to the back surface of the element. There is no protruding part and the structure of the drawer part is simple,
Further, the connection of the lead wire can be easily made to the conductive film formed on the substrate. Moreover, since the conductive connection portion between the laminated back electrode and the back electrode connection terminal portion comes into contact in a flat state, reliable contact is possible, and the contact portion between the back surface protective material and the substrate is also flat. Adhesion is possible in a state, and by adopting an appropriate adhesive and thermocompression bonding method, moisture permeation into the inside can be surely prevented, and a highly reliable element can be obtained.

[0016]

In the flat type electro-optical element in which the transparent electrode is formed on the transparent substrate, the transparent electrode on the periphery of the transparent substrate is provided with the lead terminal forming portion, and the region electrically separated from the transparent electrode is provided. The separated area is used as a connection terminal to the back electrode facing the transparent electrode, the back electrode connection terminal and the back electrode are conductively contacted, and the back electrode except the attachment part of the lead wire and the lead wire of the transparent electrode terminal is attached to the back surface. It is possible to prevent the permeation of moisture into the inside by completely covering the entire back electrode including the contact portion with the electrode with the back surface protecting material or by completely covering the entire back surface with the back surface protecting material.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The case where the present invention is applied to an electroluminescence light emitting device will be described in detail below with reference to the drawings.

FIG. 1A is a plan view in which a lead-out portion of a power supply line of an electroluminescent light emitting device is cut out to a surface of a transparent electrode, and FIG. 1B is a plan view of FIG.
The sectional view cut by the A line is shown.

On a glass substrate 1 made of borosilicate glass or the like, a transparent electrode 2 made of a conductive film of tin oxide called a Nesa film or a composite oxide of indium oxide and tin oxide called an ITO film is formed. There is. These films are obtained by forming a thin film on the surface of a glass substrate by a method such as vapor deposition in vacuum, sputtering or coating with a salt of a corresponding metal and then firing in an oxidizing atmosphere.

A back electrode connection terminal 12 is formed on the transparent electrode, a peripheral portion of which is electrically separated.

The back electrode connection terminal is formed by forming a transparent electrode by forming a mask on a portion which is separated during the formation of the transparent electrode, or by using a grinding device such as etching or a router after the transparent electrode is formed. You may separate it. Also,
It is desirable that the glass substrate be thread-faced.

The light emitting layer 3 is formed on the transparent electrode. The light-emitting layer is formed by coating zinc sulfide with light-emitting particles doped with an element such as aluminum, copper, manganese, silver and chlorine as an activator in a transparent high dielectric material. As the high dielectric material, organic cyanoethyl compounds such as cyanoethylated cellulose, cyanoethylated saccharose, cyanoethylated pullulan, and cyanoethylated poval, and organic polymer compounds such as fluororubber and epoxy resin are used. 5 to 3.0 phosphor particles,
An organic solvent such as dimethylformamide, cyclohexanone, methylpyrrolidone, propylene carbonate, ethylene glycol monomethyl ether and diethylene glycol monomethyl ether is added and fluidized for use.

The coating of the light emitting layer is performed by a screen printing method, a doctor blade method, a roll coater method or the like. The applied light emitting layer is heated on a hot plate, heated while drawing a vacuum, or heated with hot air or far infrared rays. A film is formed by drying or the like.

A dielectric layer 4, which is also called an insulating layer or a reflective layer, is formed on the side of the light emitting layer opposite to the side facing the transparent electrode. The dielectric layer is formed by applying the same fine particles of fine particles of barium titanate, titanium oxide, etc., which were dispersed and fluidized using the same organic polymer compound and solvent as those used for forming the light emitting layer, in the same manner. can do.

A back electrode 5 is provided on the dielectric layer. The back electrode is formed by solidifying and forming a conductive paste in which fine particles of silver, copper, nickel or carbon are dispersed in epoxy resin, urethane resin, acrylic resin or the like in the same manner as the light emitting layer or the dielectric layer. Also, the back electrode 5
Has a part thereof extended to the back electrode connection terminal and is in conductive contact with the terminal.

In order to strengthen the connection portion of the lead wire with the back electrode connection terminal and to secure the insulation between them and the outside to prevent a short circuit, the periphery of the back electrode connection terminal and the lead wire connection portion is made of resin. Protective film 1 after potting
3 is formed. Subsequently, the back surface and the periphery of the back electrode are covered with the back surface protective material 10 while leaving a part of the transparent electrode terminal 6 and the back electrode connection terminal 12 which are a part of the transparent electrode, or
Alternatively, a flat plate terminal is joined to the transparent electrode terminal and the back electrode connection terminal with a conductive adhesive, and the entire back surface is covered with a back surface protective material.

As the back surface protective material, a synthetic resin film, a synthetic resin film formed by vapor deposition of a metal, glass or the like, or a composite film with a metal foil is used. However, since the electroluminescence element may deteriorate early, it is preferable to use a composite film in which a thin film of aluminum is laminated between synthetic resin films or a composite film in which metal or glass is deposited. As the synthetic resin film of the composite film, polyethylene terephthalate, polycarbonate or the like can be used, and the rear surface protective material made of synthetic resin is bonded to the glass substrate and the electrode terminal by EV.
A (ethylene-vinyl acetate copolymer), a synthetic resin such as an epoxy resin, or a synthetic rubber based film-like adhesive may be used to intervene and pressurize under heating. In order to prevent moisture permeation from the bonding surface between the back surface protective material and the glass substrate, it is necessary to make the width of the bonding portion larger than a certain value. It is preferable to set it to 0.5 mm or more.

The element of the present invention to which the back surface protective material is bonded,
After solder-plating the transparent electrode terminals and the back electrode connection terminals, the lead wires are joined with solder or with a conductive adhesive, and a photocurable or thermosetting epoxy resin, etc. is used to insulate and protect the joints. When applied and solidified to form the protective film 13, an insulating film such as a polyester film is interposed between the flat plate terminal and the back protective material when the back protective material is joined, or a lead-out portion is made of an insulating resin. Can be reinforced.

FIG. 3 is an exploded perspective view showing an example of a method of manufacturing the flat electro-optical element of the present invention in order. To explain step by step, the glass substrate 1 is thread-faced and transparent on it. The back electrode connection terminal 12 is formed on the electrode 2 by a grinding device (a), and the light emitting layer 3 is formed on the transparent electrode 2 by printing (b).

A dielectric layer 4 is formed on the light emitting layer 3 so as to cover the light emitting layer (c), and a back electrode 5 having a smaller area than the dielectric layer and in conductive contact with the back electrode connecting terminal 12 is printed (d). , Fully dry and solidify.

Next, the back surface protective material 10 from which the mounting portion of the electric wire for power feeding is removed is attached and adhered to the substrate (e), and ultrasonic solder is put on the transparent electrode terminal 6 and the back surface electrode connection terminal 12 (f). ). The transparent electrode lead-out wire 7 and the back electrode lead-out wire 8 are joined to the soldered portion by soldering (g), and the terminal portion is potted (h).

FIG. 4 is an exploded perspective view showing another method of manufacturing the flat type electro-optical element of the present invention.

The transparent electrode 2 and the back electrode connection terminal 12 are patterned and formed on the glass substrate 1 in advance (a), and the light emitting layer 3 is formed thereon by printing (b).

A dielectric layer 4 is formed on the light emitting layer 3 so as to cover the light emitting layer (c), and a back electrode 5 having a smaller area than the dielectric layer and in conductive contact with the back electrode connecting terminal 12 is printed (d). , Fully dry and solidify.

Next, the flat plate terminal 14 for power supply is connected to the transparent electrode 2.
Transparent electrode terminal 6 and back electrode connection terminal 1 which are a part of
2 is bonded with a conductive adhesive (e), the back surface protective material 10 is attached to the back electrode and bonded to the substrate (f). that time,
An insulative film such as a polyester film may be interposed between the flat plate terminal and the back surface protective material, and one end of the insulative film may be extended along the flat plate terminal and bonded together to reinforce the drawn portion (g).

Example 1 A back electrode terminal was formed on the periphery of a base material in which a thin film of tin oxide (SnO ₂ ) was formed as a transparent conductive film on a borosilicate glass having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. In order to do so, as shown in FIG. 3 (a), a region of 5 mm in length and 5 mm in width from one end of the base material was removed with a grinding machine in a width of 1 mm to form an electrically isolated region. ..

Further, except for the range of 6 mm from the outer end on the terminal lead-out side and 3 mm from the remaining three sides, 1 part of the zinc sulfide-based light-emitting body was mixed with 0.3 part of cyanoethylated pullulan and 0.5 part of dimethylformamide. The composition dispersed in the solution was applied in a thickness of 40 μm and dried by heating at 120 ° C. for 2 hours to form a light emitting layer.

On the light emitting layer, 1 part of barium titanate (BaTiO ₃ ) was used as a dielectric, and cyanoethylated pullulan of 0.
A composition dispersed in a solution of 2 parts and 0.3 part of dimethylformamide was applied in a thickness of 40 μm with each side being 1 mm larger than the light emitting layer, and dried by heating at 120 ° C. for 2 hours to form a dielectric layer. ..

On the dielectric layer, the thermosetting silver is smaller than the circumference of the dielectric layer by 1 mm, and only a part of the dielectric layer extends to the back electrode connecting terminal previously formed by the grinder so as to make conductive contact with the depth of 1 mm. The paste was applied to form a back electrode.

Subsequently, the connecting portion of the lead wire of the transparent electrode terminal and the rear electrode connecting terminal was cut off from the outer end by 2 mm in depth, and a rear surface protective material made of a composite film of 100 mm in length and 100 mm in width was sandwiched with a synthetic rubber thermal adhesive film. It was superposed on the back electrode and thermocompression-bonded at a temperature of 130 ° C. and a pressure of 1 Kg / cm ² .

Ultrasonic solder was put on the transparent electrode terminal and the back electrode connecting terminal, and the lead wire was joined with the solder, and then epoxy resin was applied and solidified to insulate the terminal portion and fix the lead wire.

The obtained electroluminescent light emitting device was subjected to a moisture permeability test at 60 ° C. and a relative humidity of 95% for 96 hours. No deterioration of the device due to moisture permeability was observed.

Example 2 A thin film of tin oxide (SnO ₂ ) as a transparent conductive film was formed on a borosilicate glass having a length of 100 mm, a width of 100 mm and a thickness of 2 mm, and a lead wire for power supply as shown in FIG. 4A. 3 sides excluding the side where the wiring is provided, and the side where the lead wire is provided is 1 mm from the periphery of the base material to the inside, and the back electrode connection terminal 1
6 mm from the side forming 2 and a space of 1 mm was provided between the transparent electrode 2 and the back electrode connecting terminal 12 to form a pattern to form a substrate.

3 mm except for the side where the lead line is provided on the substrate, 3 mm for the side where the lead line is provided, and 7 mm for the side where the lead line is provided. A dielectric layer 1 mm larger on each side was formed on the light emitting layer. A thermosetting silver paste was applied on the dielectric layer so as to be 1 mm smaller than the periphery of the dielectric layer and only part of the dielectric layer extended to the back electrode connection terminal 12 and had a conductive contact with a depth of 1 mm to form a back electrode. ..

Subsequently, the flat plate terminal is joined to the transparent electrode terminal and the back electrode terminal with a conductive adhesive, and the insulating film which covers the connecting portion of the flat plate terminal and extends to the outside of the substrate along the flat plate terminal is placed. Then, the back surface protective material composed of the composite film was superposed on the entire back surface of the substrate with the synthetic rubber thermal adhesive film sandwiched therebetween, and thermocompression bonded at a temperature of 130 ° C. and a pressure of 1 Kg / cm ² .

The electroluminescence light emitting device thus obtained was subjected to a moisture permeability test at 60 ° C. and a relative humidity of 95% for 96 hours, and no deterioration of the device due to moisture permeability was observed.

Comparative Example In the structure of FIG. 2 in which the lead wire is taken out from the back of the back electrode manufactured by using the same material as that of the embodiment, the taken-out portion is found when the moisture permeability test similar to that of the embodiment 1 is performed. Central deterioration was observed.

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, in a planar electro-optical element such as an electroluminescence light emitting element, a peripheral portion of a transparent electrode formed on a transparent substrate is provided with a region electrically separated from the transparent electrode. The area is used as a back electrode connection terminal facing the transparent electrode, the back electrode and the back electrode connection terminal are conductively contacted by a conductive material, and the transparent electrode terminal and the back electrode connection terminal formed on a part of the transparent electrode are transparent electrode lead wires. Except for the connection part of and the connection part of the back electrode lead wire, it is covered with a back surface protective material, or the flat plate terminal is joined to the transparent electrode terminal and the back electrode connection terminal,
Since the back surface protective material including the connecting portion is covered, moisture permeation from the lead-out portion of the power supply line can be prevented, and a highly reliable element can be obtained. Also,
When the flat plate terminal is used as the lead wire, the contact area with the substrate surface increases, and the flat plate terminal can be thinned to about 100 μm, so that the entire thickness can be thinned.

[Brief description of drawings]

FIG. 1 is a plan view in which a lead-out portion of a power supply line of an electroluminescence light-emitting element is cut out to a surface of a transparent electrode, and a cross-sectional view taken along line AA in FIG.

FIG. 2 is a plan view (a) and FIG. 2 (a) showing a part of the back surface protection material of the electroluminescence light-emitting element, in which the power supply line is drawn out from the back surface, with a part cut away.
It is sectional drawing (b) cut by the B line.

FIG. 3 is an exploded perspective view showing an embodiment of a method for manufacturing an electroluminescent light emitting device.

FIG. 3 is an exploded perspective view showing another embodiment of the method for manufacturing the electroluminescent light emitting element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Transparent electrode, 3 ... Light emitting layer, 4 ... Dielectric layer, 5 ... Back electrode, 6 ... Transparent electrode terminal, 7 ... Transparent electrode lead wire, 8 ... Back electrode lead wire, 9 ... Metal foil, DESCRIPTION OF SYMBOLS 10 ... Back protective material, 11 ... Filling fixing part, 12 ... Rear electrode connection terminal, 13 ... Protective film, 14 ... Flat plate terminal, 15 ... Insulating film

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[Procedure amendment]

[Submission date] December 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a plan view in which a lead-out portion of a power supply line of an electroluminescence light-emitting element is cut out to a surface of a transparent electrode, and a cross-sectional view taken along line AA in FIG.

FIG. 2 is a plan view (a) and FIG. 2 (a) showing a part of the back surface protection material of the electroluminescence light-emitting element, in which the power supply line is drawn out from the back surface, with a part cut away.
It is sectional drawing (b) cut by the B line.

FIG. 3 is an exploded perspective view showing an embodiment of a method for manufacturing an electroluminescent light emitting device.

FIG. 4 is an exploded perspective view showing another embodiment of the manufacturing method of the electroluminescence light emitting device.

[Explanation of Codes] 1 ... Glass substrate, 2 ... Transparent electrode, 3 ... Light emitting layer, 4 ... Dielectric layer, 5 ... Back electrode, 6 ... Transparent electrode terminal, 7 ... Transparent electrode lead wire, 8 ... Back electrode lead wire, 9 ... Metal foil, 10 ... Back protective material, 11 ... Filling and fixing part, 12 ... Back electrode connecting terminal, 13 ... Protective film, 14 ... Plate terminal, 15 ... Insulating film

Claims (3)

[Claims] 1. A flat type electro-optical device having a transparent electrode formed on a transparent substrate, wherein a transparent electrode in a peripheral portion of the transparent substrate is provided with an electrically isolated region, and the separated region is opposed to the transparent electrode. A planar electro-optical element characterized by being used as an electrode connection terminal. 2. The flat electro-optical element according to claim 1, wherein the separated region and the back electrode are connected by a conductive material. 3. The flat electro-optical element according to claim 1, which is an electroluminescence element.