JP2003157967A - El panel and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EL panel which can be surely sealed by adhesion resin by preventing the variations of the width/thickness of sealing caused by the uneven coating of the adhesion resin with a simple working process, capable of eliminating the increase of process caused by an admixtier of spacers and formation of props and improving the state lowering of adhesive force caused by the admixture of the spacer, and to provide a manufacturing method of the same. SOLUTION: The EL panel comprises at least a base plate, an EL structure laminated on the base plate, sealing plates arranged on the EL structure at prescribed spaces, and adhesion resin for sealing which fixes the sealing plates to the base plate and hermetically seals the EL structure. The EL panel has an adhesion resin stopping structure contacting with the adhesion resin for sealing at a part of a construction member of the EL structure. The manufacturing method of the EL panel is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an E having an EL element which is thin and is preferably used as a flat plate-shaped display means.
The present invention relates to an L panel, and particularly to a panel sealing structure.

[0002]

2. Description of the Related Art Conventionally, an electroluminescence formed on an insulating substrate, which is formed by sequentially laminating a first electrode, a first insulating layer, a light emitting layer, a second insulating layer, and a second electrode. The element (EL element) has a problem that when the electroluminescent film absorbs moisture, the characteristics of the electroluminescent film are deteriorated, causing a serious obstacle to light emission.

Therefore, it is necessary to perform sealing so that moisture does not enter the electroluminescent film, and a typical method therefor is, for example, JP-A-62-4498.
There is a method as shown in Japanese Patent Publication No. That is, the electroluminescent film is casing with the insulating substrate and the sealing plate, and the periphery of the insulating substrate and the periphery of the sealing plate are sealed with resin. After that, the casing formed by the insulating substrate and the sealing plate is filled with sealing oil such as silicone oil.

Further, in recent years, it has been generally practiced to seal by sealing inert gas or dry air without sealing sealing oil or the like.

When sealing is performed using such a sealing plate, the sealing plate contacts or interferes with the light emitting portion (pixel or display portion) of the EL element and damages it. In order to prevent this, a structure for holding the EL element at a predetermined height is required.

For this reason, conventionally, the height (seal thickness) of the substrate and the sealing plate has been adjusted by mixing a spacer in the sealing adhesive resin or forming a pillar on the substrate.

Further, it is difficult to adjust the coating amount of the sealing resin, and if the coating amount is too large, the sealing resin reaches the EL element and exerts an adverse effect, or if the coating amount is too small, the sealing resin is sealed. There was a problem such as becoming insufficient.

Furthermore, when applying a sealing resin, EL
If the coating is applied so that the whole structure is surrounded by a so-called single stroke, when the sealing plate is pressed and fixed from above, the gas inside is compressed and the pressure inside the sealed space is reduced. Will rise. Then, this remains as a positive pressure as it is after the sealing, and a stress is generated from the inside of the sealed space to the outside. Then, due to such stress, thermal shock, and long-term storage, peeling of the sealing plate or resin occurs, which causes a sealing failure.

For this reason, conventionally, in order to control the sealing width of the sealing adhesive resin, a pressure gap generated when the sealing plate is made to escape the resin and a pressure is generated when the substrate and the sealing plate are bonded together. In order to escape the above, a technique such as providing a through hole in the substrate has been used.

However, even if the counterbore is formed on the sealing plate or the through hole is formed on the substrate, the cost is increased and it is not suitable for mass production.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a seal width and a seal width due to application variation of adhesive resin in a simple working process.
An object of the present invention is to provide an EL panel capable of reliably sealing with an adhesive resin while suppressing a variation in thickness, and a manufacturing method thereof.

It is another object of the present invention to provide an EL panel and a manufacturing method thereof, which can eliminate the increase in the number of steps due to the incorporation of spacers and the formation of columns, and can improve the reduction of the adhesive force due to the incorporation of spacers.

[0013]

[Means for Solving the Problems] (1) Substrate, EL structure laminated on the substrate, sealing plate disposed on the EL structure with a predetermined gap, and sealing At least a sealing adhesive resin that fixes the plate on the substrate and seals the EL structure, and a sealing adhesive resin is in contact with a part of the constituent members of the EL structure. EL panel having an adhesive resin stopping structure for regulating the temperature. (2) The EL structure includes at least an electrically insulating substrate, a first electrode, a thick film dielectric layer, a light emitting layer, and
The EL panel according to (1) above, in which a thin film dielectric layer and a second electrode are sequentially laminated. (3) The EL panel according to (2), wherein the adhesive resin stopping structure is formed of the same material as the thick film dielectric layer. (4) In the EL structure, at least an electrically insulating substrate, a first electrode, a thick film dielectric layer, a flattening layer, a light emitting layer, a thin film dielectric layer, and a second electrode layer are sequentially arranged. The EL panel of (1) above, which is laminated. (5) The EL panel according to (4), wherein the adhesive resin stopping structure is made of the same material as the flattening layer. (6) The EL element according to any one of (1) to (5) above, wherein the space in which the EL structure is sealed has an atmosphere equal to or depressurized from atmospheric pressure. (7) A substrate on which the EL structure is stacked is housed in a decompression tank, the pressure in the decompression tank is reduced to a predetermined pressure lower than atmospheric pressure, and then a predetermined region surrounding the EL structure on the substrate. A method for manufacturing an EL panel, in which a sealing adhesive resin is applied with a single stroke, the sealing plate is fixed, and then the reduced pressure body is released to take out the substrate from the reduced pressure tank. (8) The method for manufacturing an EL panel according to (7), wherein the space in which the EL structure of the substrate taken out from the decompression tank is sealed has an atmosphere equal to or depressurized from atmospheric pressure.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The EL panel of the present invention comprises a substrate,
An EL structure laminated on this substrate, a sealing plate arranged with a predetermined gap on this EL structure, and this sealing plate is fixed on the substrate and the EL structure is hermetically sealed. A sealing adhesive resin is provided, and an adhesive resin stopping structure for contacting the sealing adhesive resin and restricting the sealing adhesive resin is provided on a part of the constituent members of the EL structure.

As described above, at the same time when the thick film dielectric layer or the flattening layer is formed, the adhesive resin stopping structure is formed as a part of the structure (thick film dielectric layer or the flattening layer),
As a result, the adhesive resin for sealing is regulated and blocked, so that fluctuations in the seal width and thickness due to variations in the application of the adhesive resin can be suppressed and sealing can be reliably performed with the adhesive resin.

Further, the above structure can also function as a spacer, and it is possible to omit an increase in the number of steps due to the incorporation of spacers and the formation of struts, and to improve the reduction of the adhesive force due to the incorporation of spacers. You can also

That is, in the present invention, by providing the adhesive resin stopping structure for regulating the flow range of the sealing adhesive resin,
Even if some coating unevenness occurs, it is regulated by the adhesive resin stop structure, and the sealing adhesive resin can be uniformly arranged at a predetermined position, improving work efficiency and performing reliable sealing. You can

As such an adhesive resin stopping structure,
Although it can be formed separately from the EL structure, it is formed by using the constituent material of the EL structure from the viewpoints of efficiency of work process, improvement of productivity, and effective use of materials, and further, each structure It is preferably formed by the same process as any one of the portions. Specifically, the following two modes can be mentioned.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of the present invention.
3A and 3B are a plan view and a cross-sectional view showing the EL panel according to the embodiment, and FIG. 1 corresponds to a cross-sectional view taken along the line AA ′ of FIG.

In the figure, the EL panel is composed of a substrate 1, an EL structure 2 formed on the substrate, an adhesive resin stopper formed integrally with the EL structure by a part of its constituent members. It has a structure 3, an adhesive resin 4 for sealing, and a sealing plate 5 fixed by the adhesive resin 4.

By providing the adhesive resin stopping structure 3 as described above, the adhesive resin layer 4 coated on the outside of the EL structure is provided.
However, they are regulated by the adhesive resin stopping structure 3 and flow in such a manner that they are shaped within a predetermined region and are evenly arranged. Therefore, it is not necessary to regulate the application amount and the application width of the adhesive resin so accurately, the application work can be roughly performed to some extent, and the workability is significantly improved. Moreover, since the applied adhesive resin is regulated to have a uniform width and thickness, reliable sealing can be performed.

The adhesive resin stopping structure may be made of the same material as that of the EL structure, and may be integrally formed with this. More specifically, it is advisable to increase the thickness of a part of the thick film dielectric layer of the EL structure constituting layer to form the adhesive resin stopping structure. That is, when the thick film dielectric is formed by the screen printing method, the thick film dielectric is printed so as to have a predetermined width and thickness from the outer peripheral portion of the thick film dielectric to the inner side as a bank for sealing in the upper layer portion. Then, after that, another constituent layer is formed to form an inorganic EL structure.

By forming the adhesive resin stopping structure integrally with the EL structure, preferably the thick film dielectric layer, in the same step as described above, a manufacturing process dedicated to the adhesive resin stopping structure is unnecessary. Therefore, reliable sealing can be performed without increasing the number of steps.

Moreover, this adhesive resin stopping structure is
Since it is formed higher than the surface position of the display portion 7 of the structure, it also has a function as a spacer. As a result, it is not necessary to mix a spacer in the sealing adhesive resin, and the deterioration of the sealing function can be suppressed.

Further, the display unit 7 for actually displaying is
Since it is separated from the region where the adhesive resin stopping structure 3 is formed to some extent, it is not affected by the adhesive resin stopping structure or the adhesive resin.

The size of the adhesive resin stopping structure in the first aspect may have a function as a spacer and a height necessary to regulate the adhesive resin. Specifically, width 1-5 mm, preferably 2-3 mm, height 5-50
μm, preferably about 5 to 20 μm. Further, it is preferable that the distance from the outer edge of the display portion 7 is 1 mm or more, particularly about 1 to 5 mm.

[Second Embodiment] FIGS. 3 and 4 show a second embodiment of the present invention.
4A and 4B are a plan view and a cross-sectional view showing the EL panel according to the embodiment, and FIG. 3 corresponds to a cross-sectional view taken along the line BB ′ of FIG.

In the figure, the EL panel is integrally formed by the substrate 1, the EL structure 2 formed on the substrate, and the planarization layer 6 of the EL structure, as a part of the components. It has the formed adhesive resin stopping structure 6a, the sealing adhesive resin 4, and the sealing plate 5 fixed by the adhesive resin 4.

By providing such an adhesive resin stopping structure 6a, the adhesive resin layer 4 coated on the outside of the EL structure is regulated by the adhesive resin stopping structure 6a and shaped into a predetermined area. So that they flow and are evenly distributed. Therefore, the coating work can be performed roughly to some extent, and the workability is significantly improved. Moreover, since the applied adhesive resin is regulated to have a uniform width and thickness, reliable sealing can be performed.

In this aspect, the sealing plate 5 is arranged in close contact with the EL structure including the flattening layer 6, that is, the display region. Examples of such a mode in which the sealing plate 5 is brought into close contact include a case where an optical functional layer such as a color filter layer, a fluorescence conversion layer, or a polarizing layer is formed on the sealing plate 5. Therefore, although not shown in FIG. 4, the constituent layers of another EL structure, for example, a light emitting layer, an insulating layer, an electrode layer, etc. are actually formed on the planarization layer 6, and the sealing layer 6 is sealed. Board 5
A color filter layer or the like is preferably formed on the EL structure side.

The adhesive resin stopping structure in this case is also preferably made of the same material as the EL structure and formed integrally therewith. More specifically, it is advisable to increase the thickness of a part of the excess portion of the planarization layer in the EL structure constituting layer to form the adhesive resin stopping structure. That is, a thick film dielectric is formed, and a regulation member such as a tape is attached to a region required as a seal width when forming the flattening layer. For example,
When a tape having a desired thickness is attached, a solution of the flattening layer forming material solution is accumulated in the step portion. When firing, the tape is peeled off, but the portion where the flattening layer constituent material solution is accumulated is thickened and a bank having a desired thickness can be formed.

The display portion 7 in the second mode is also apart from the region where the adhesive resin stopping structure 6a is formed to some extent, so that it is not affected by the adhesive resin stopping structure or the adhesive resin.

The size of the adhesive resin stopping structure 6a in the second aspect may be any height as long as it is necessary to regulate the adhesive resin. Specifically, width 0.5 to 2.0
mm, preferably 0.5 to 1.0 mm, and the height must be lower than the thickness of the thick film dielectric layer of the display part, but usually 5 to
It is about 20 μm, preferably about 10 to 20 μm. In addition, the thick film dielectric having the display portion 7, that is, the EL structure 2
1 mm or more, especially about 1 to 5 mm from the outer edge of.

Adhesive resin stopping structure 6 in the second embodiment
Since a uses the accumulation of the flattening layer formed on the outer side of the EL structure body, there is no effect on the body.

The adhesive resin stopping structure 6a in the second mode can be formed, for example, as follows.

First, the electrode layer and the thick film dielectric layer are formed on the substrate without forming the sealing bank on the thick film dielectric layer of the display section. Next, as shown in FIG. 5, a tape is attached to a region required as a seal width when the flattening layer precursor solution is spin-coated. The thickness of the tape is 50 ~ 20
It is 0 μm, particularly about 50 to 100 μm.

Next, as shown in FIG. 6, after applying a tape, the flattening layer precursor solution is spin-coated to form a pool of the flattening layer precursor solution in the step portion. Next, when the tape is peeled off and baked, the portion where the planarizing layer precursor solution is accumulated is formed thick as shown in FIG. 7, and the adhesive resin stopping structure 6a is completed.

The precursor solution used in the solution coating and firing method for forming the flattening layer is a metal organic compound of a metal element forming the dielectric layer, or a metal alkoxide and these metal source elements and organic substances in the solution. It is composed of a complex and a volatile solvent.

In the film formation method of the solution coating and baking method, the precursor layer is formed on the substrate by applying the precursor solution to the substrate by a method such as spin coating, dip coating or spray coating. By firing this precursor layer, the organic components in the precursor are removed, the ultrafine oxide layer is formed by the bond of the metal element and oxygen, and the oxide is further fired to form the dielectric layer. To be done.
In addition, when applying to the said 2nd aspect, it is preferable to use spin coating.

Further, the adhesive resin stopping structure in the second mode may be formed by using the material of the thick film dielectric layer 2 as shown in FIG. That is, at the time of forming the thick film dielectric layer, the base portion 2a of the adhesive resin stopping structure 6a having a predetermined height and width is simultaneously formed. Then, the above-mentioned flattening layer 6
At the time of formation, if coating is performed without taping, a flattening layer is also formed on the base portion 2a, and a bank-shaped adhesive resin stopping structure 6a is formed.

The flattening layer 6 does not necessarily have to be formed on the base portion 2a, and the base portion 2a of the thick film dielectric is used.
It is also possible to form an adhesive resin stop structure only by using the above. Other configurations are the same as those of the EL panel shown in FIGS.
The same components are assigned the same reference numerals and explanations thereof are omitted.

By forming the adhesive resin stopping structure according to the first or second aspect as described above, the adhesive resin for sealing is effectively regulated, and the coating width,
The coating thickness can be within the specified range, and reliable sealing can be performed.

The sealing operation can be performed as follows.

After the inorganic EL structure (hereinafter referred to as a panel) completely formed on the substrate and a sealing member, for example, a glass plate are cleaned with UV ozone, the outer peripheral portion of the sealing glass is covered with an applying means such as a dispenser. Apply the sealing resin with one stroke.

The encapsulating resin used at this time is not particularly restricted and has little influence on the EL structure,
Any material can be used as long as it can be surely sealed. Specifically, a UV curable resin is preferable, and an epoxy resin is particularly preferable. The viscosity of the sealing adhesive resin is 10
About 2000 pa.s is preferable.

When applying using a dispenser, the inner diameter of the nozzle is preferably 0.5 to 1.0 mm, the gap from the sealing plate is 200 to 300 μm, and the speed is 1 to 5 mm / S.

The application position of the sealing resin is preferably 0.5 to 2 mm inside the outer periphery of the sealing member.

In the present invention, it is desirable to carry out the sealing operation under a predetermined reduced pressure. By performing the sealing operation under reduced pressure, the sealed space after sealing can be brought to atmospheric pressure or a slight reduced pressure state, and it is possible to suppress the promoting phenomenon such as peeling due to the internal pressure. It is possible to manufacture a panel that is resistant to light.

Specifically, after applying the sealing resin, the panel is placed in the vacuum chamber downward (the inorganic EL structure is directed to the glass side) and the sealing glass is placed upward (the resin application surface is directed to the panel side). Set to.

Next, evacuation and purging of the sealing gas are repeated a predetermined number of times, preferably 2 to 10 times, to create an atmosphere of the sealing gas dry. After that, the pressure is reduced to -50 to -100 kPa, and the panel and the sealing glass are fixed with a gap of about half the height of the applied resin.

The panel and the sealing glass are sealed with resin, and the pressure in the sealing space is approximately -25 to -50 kPa.
It becomes higher than the pressure in the chamber. For this reason, if left as it is, there is a risk that the sealing resin will be broken, so it is advisable to start the leak in the chamber within about 0.5 to 2 seconds after attachment and return to atmospheric pressure within about 5 to 30 seconds. After that, UV irradiation is performed to cure the sealing resin, and the process is completed.

In the above description, glass is used as an example of the sealing member, but the sealing member is not limited to glass, and a material similar to the substrate material may be used, or a plastic material or the like may be used. A resin material can also be used. When the emitted light is taken out from the sealing member side, the sealing member needs to have a predetermined translucency. The thickness of the sealing member depends on the material, but is usually 0.5 to 3.0 mm.
It is a degree.

The basic structure of the EL device of the present invention is shown in FIG. The EL device of the present invention includes, for example, a lower electrode layer 22 formed in a predetermined pattern on a substrate 1 having electrical insulation.
A thick film dielectric layer 23 is further laminated thereon, and a dielectric layer 24 formed by a solution coating method is further laminated thereon to form a multilayer dielectric layer.

Then, the thin film insulator layer 25, the light emitting layer 26, and the thin film insulator layer 2 are provided on the multilayer dielectric layers 23 and 24.
7. The transparent electrode layer 28 is laminated. The thin film insulator layers 25 and 27 may be omitted. The lower electrode layer 22 and the upper transparent electrode layer 28 are formed in stripes in directions orthogonal to each other. Then, the lower electrode layer 22 and the upper transparent electrode layer 28 are arbitrarily selected, and light is emitted from a specific pixel by selectively applying a voltage from the AC power supply / pulse power supply 10 to the light emitting layer in the orthogonal portion of both electrodes. Obtainable.

The substrate is not particularly limited as long as it has electrical insulation properties and can maintain a predetermined heat resistance strength without contaminating the lower electrode layer and the dielectric layer formed thereon.

As a specific material, alumina (Al ₂
O ₃ ), quartz glass (SiO ₂ ), magnesia (Mg
O), forsterite (2MgO · SiO ₂ ), steatite (MgO · SiO ₂ ), mullite (3Al ₂ O ₃
・ 2SiO ₂ ), beryllia (BeO), zirconia (Z
rO ₂ ), aluminum nitride (AlN), silicon nitride (SiN), silicon carbide (SiC) and other ceramic substrates, crystallized glass, high heat resistant glass, etc. may be used.
Further, a metal substrate or the like that has been subjected to enamel treatment can also be used.

When the display device is of a simple matrix type, the lower electrode layer is formed to have a plurality of stripe patterns. Further, since the line width becomes a width of one pixel and the space between the lines becomes a non-light emitting region, it is preferable to make the space between the lines as small as possible. Specifically, depending on the resolution of the target display, for example, a line width of 200 to 500 μm, a space 20
Approximately 50 μm is required.

As a material for the lower electrode layer, a material which has high conductivity, is not damaged when the dielectric layer is formed, and has low reactivity with the dielectric layer or the light emitting layer is preferable. Such lower electrode layer materials include Au, Pt, Pd,
Noble metals such as Ir and Ag, Au-Pd, Au-Pt and A
Noble metal alloys such as g-Pd and Ag-Pt, and Ag-Pd-
An electrode material containing a noble metal such as Cu as a main component and a non-metal element added thereto is preferable because oxidation resistance to an oxidizing atmosphere during firing of the dielectric layer can be easily obtained. In addition, ITO or SnO ₂
(Nesa film), an oxide conductive material such as ZnO-Al may be used. Further, a base metal such as Ni or Cu may be used, and these nonmetals may oxidize the oxygen partial pressure when firing the dielectric layer. It can also be used by setting it in a range that is not controlled.

As a method of forming the lower electrode layer, a known technique such as a sputtering method, a vapor deposition method, a plating method may be used.

The thick-film dielectric layer needs to have a high dielectric constant and a high breakdown voltage, and further needs to be a substance that can be fired at a low temperature in consideration of the heat resistance of the substrate.

Here, the thick film dielectric layer is a ceramic layer formed by firing a powdery insulating material by a so-called thick film method. This thick-film dielectric layer is formed by, for example, printing an insulating paste made by mixing a powdery insulating material with a binder and a solvent on a substrate on which a lower electrode layer is formed, and firing it. be able to. Alternatively, a green sheet may be formed by casting an insulating paste, and the green sheets may be stacked.

The conditions for the binder removal treatment performed before firing are as follows:
It may be a normal one.

The atmosphere for firing may be appropriately determined according to the type of the conductive material in the electrode layer paste, but when firing in an oxidizing atmosphere, ordinary firing in air may be performed.

The holding temperature during firing may be appropriately determined according to the type of the insulating layer, but is usually 700 to 1200 ° C.
The degree is preferably 1000 ° C. or lower. Further, the temperature holding time during firing is 0.05 to 5 hours, particularly 0.1 to 3 hours.
Time is preferred.

Further, an annealing treatment may be applied if necessary.

The film thickness of the thick film dielectric is required to be thick in order to eliminate pin steps formed by the steps of electrodes and dust in the manufacturing process, and at least 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more is required.

For example, if the film thickness of the dielectric layer is 20 μm, its relative permittivity must be 200 to 800 to 1800 or more. If the film thickness of the dielectric layer is 30 μm, its relative permittivity is 300. ~ 1200-2700 is required.

Various materials can be considered as such a high-dielectric-constant thick film material, but a high-dielectric-constant ceramic composition that can be formed at a low temperature is desirable in consideration of the heat resistance of the substrate material.

For example, BaTiO ₃ , (Ba _x Ca _1-x ) T
iO ₃ , (Ba _x Sr _1-x ) TiO ₃ , PbTiO ₃ , P
b (Zr _x Ti _1-x ) _{3 and} other dielectric materials having a perovskite structure, ferroelectric materials, and Pb (Mg _1/3 Ni _2/3 ) O ₃
And other composite perovskite relaxor type ferroelectric materials, Bi ₄ Ti ₃ O ₁₂ , and bismuth layered compounds represented by SrBi ₂ Ta ₂ O ₉ (Sr _x Ba _1-x ) Nb ₂
Tungsten bronze type ferroelectric materials typified by O ₆ and PbNb ₂ O ₆ are preferable because of their high dielectric constant and easy firing.

A dielectric material containing lead in its composition
Has a low melting point of 888 ° C., and lead oxide and other
Oxide material such as SiO₂ Or CuO, Bi₂O₃ ,
Fe₂O ₃ 700 ℃ to 800 ℃ low temperature between
Since a liquid phase is formed by, it is easy to fire at low temperature, and
It is preferable because a high dielectric constant is easily obtained. For example, Pb (Zr_x
Ti_1-x)₃Perovskite structure dielectric material such as Pb
(Mg_1/3Ni_2/3) O₃Complex Perovska represented by
Itrilaxer type ferroelectric material and PbNbO₆Etc.
Tungsten bronze type ferroelectric materials represented are listed.
To be These are ordinary ceramics such as alumina ceramics.
800-900 ° C, which is the maximum heat resistant temperature of the Ramix substrate
The dielectric constant of 1,000 to 10,000 is easily induced at the firing temperature of
An electric body can be formed.

The high dielectric constant dielectric layer laminated on the thick film dielectric layer has the purpose of improving the surface flatness of the thick film dielectric layer, and therefore it is necessary to use the solution coating firing method.

The solution coating baking method is a sol-gel method or MOD.
A method of forming a dielectric layer by applying a precursor solution of a dielectric material to a substrate and firing the solution.

The sol-gel method is generally a method in which a predetermined amount of water is added to a metal alkoxide dissolved in a solvent, and a precursor solution of a sol having an MOM bond formed by hydrolysis and polycondensation reaction is applied to a substrate. It is a method of forming a film by firing and baking. In addition, MOD (Metallo-Organic Decom
The position) method is a method of forming a film by dissolving a metal salt of a carboxylic acid having an MO bond in an organic solvent to form a precursor solution, applying the solution on a substrate, and baking the solution. Here, the precursor solution refers to a solution containing an intermediate compound produced by dissolving a raw material compound in a solvent in a film forming method such as a sol-gel method or a MOD method.

The sol-gel method and the MOD method are not completely separate methods but are generally used in combination with each other. For example, when forming a PZT film, it is common to use lead acetate as a Pb source and an alkoxide as a Ti, Zr source to prepare a solution. The two methods of the sol-gel method and the MOD method may be collectively referred to as the sol-gel method. In either case, the precursor solution is applied to the substrate and baked to form a film. Then, the solution coating firing method is used. Further, even a solution obtained by mixing a submicron size dielectric particle and a dielectric precursor solution is included in the dielectric precursor solution of the present invention, and even when the solution is applied to a substrate and baked. It is included in the solution coating and baking method of the present invention.

In both cases of the sol-gel method and the MOD method, the solution coating and firing method uniformly mixes the constituent elements of the dielectric material in the order of sub-μm or less, and therefore, it is essential to form a dielectric material by the thick film method. In comparison with the method using ceramic powder sintering, it is possible to synthesize a dense dielectric at an extremely low temperature.

The greatest purpose of using the solution coating and baking method is that the dielectric layer formed by this method is characterized in that it is formed by the step of applying and baking the precursor solution, so that the concave portion of the substrate is Since a thick layer is formed on the convex portion and a thin layer is formed on the convex portion, the step on the substrate surface is flattened, and the surface flatness of the thick film ceramics dielectric layer of the EL element is significantly improved. It is possible to significantly improve the uniformity of the thin film light emitting layer.

Therefore, the film thickness of the dielectric layer formed by the solution coating and firing method is preferably 0.5 μm or more, preferably 1 μm or more, more preferably 2 μm or more in order to sufficiently flatten the irregularities on the thick film surface. Be done.

The effective relative permittivity of the whole laminated dielectric layer formed by the solution coating and firing method by adding the high dielectric constant dielectric layer is preferably 1200 when the thickness of the thick film layer is 30 μm. ~ 2700 or more. Therefore, for example, if a thick film having a relative dielectric constant of 4000 is used and an effective dielectric constant of 2700 is to be obtained, the dielectric layer formed by the solution coating and firing method needs to have a ratio of relative dielectric constant to film thickness of 277 or more. If the dielectric constant of the thick film dielectric layer is 3000, the ratio will be 900.

As described above, the film thickness of the dielectric layer formed by the solution coating and baking method is at least 0.5 μm or more,
It is preferably 1 μm or more, more preferably 2 μm or more. Therefore, it is desirable that the relative permittivity is as high as possible, and it is at least 250 or more, preferably 500 or more.

As described above, the high dielectric constant layer formed by the solution coating and firing method needs to have a large film thickness and a high dielectric constant. Examples of such a high dielectric constant material include BaTiO ₃ , (Ba _x Ca _1-x ) TiO ₃ , and (Ba
_x Sr _1-x ) TiO ₃ , PbTiO ₃ , Pb (Zr _x Ti
_1-x ) _{3 and} other dielectric materials having a perovskite structure, ferroelectric materials, and composite perovskite relaxor type ferroelectric materials such as Pb (Mg _1/3 Ni _2/3 ) O ₃ and B,
i ₄ Ti ₃ O ₁₂ , bismuth bismuth layer compound represented by SrBi ₂ Ta ₂ O ₉ (Sr _x Ba _1-x ) Nb ₂ O ₆ ,
Examples thereof include a tungsten bronze type ferroelectric material typified by PbNbO _{6 and the} like. Among these, BaT
A ferroelectric material having a perovskite structure such as iO ₃ or PZT is preferable because it has a high dielectric constant and is easily formed at a relatively low temperature.

The material for the light emitting layer is not particularly limited, but known materials such as Mn-doped ZnS described above can be used. Among these, SrS: Ce is particularly preferable because excellent characteristics can be obtained. The thickness of the light emitting layer is not particularly limited, but if it is too thick, the driving voltage increases, and if it is too thin, the luminous efficiency decreases. Specifically, it depends on the light emitting material, but preferably 100 to 20.
It is about 00 nm.

As a method of forming the light emitting layer, a vapor deposition method can be used. As the vapor deposition method, a physical vapor deposition method such as a sputtering method or a vapor deposition method, or a chemical vapor deposition method such as a CVD method is preferable. Further, as described above, especially SrS:
When the light emitting layer of Ce is formed, the substrate temperature during film formation is set to 50 by electron beam evaporation in an H ₂ S atmosphere.
A high-purity light emitting layer can be obtained by forming the film while keeping it at 0 ° C to 600 ° C.

After forming the light emitting layer, heat treatment is preferably performed. The heat treatment may be performed after stacking the electrode layer, the dielectric layer, and the light-emitting layer from the substrate side, or forming the electrode layer, the dielectric layer, the light-emitting layer, the insulating layer, or the electrode layer on the electrode layer from the substrate side. After that, heat treatment (cap annealing) may be performed. The temperature of the heat treatment depends on the light emitting layer to be formed, but is preferably 300 ° C. or higher, more preferably 400 ° C. or higher,
It is below the firing temperature of the dielectric layer. Processing time is 10-60
It is preferably 0 minutes. The atmosphere during the heat treatment may be selected from air, N ₂ , He, Ar and the like depending on the composition of the light emitting layer and the forming conditions.

Thin film insulator layer (25) and / or (2
Although 7) may be omitted as described above, it is preferable to have it.

As a function of this thin film insulator layer, the electronic state of the interface between the light emitting layer and the dielectric layer is adjusted to stabilize and improve the efficiency of electron injection into the light emitting layer. The main purpose is to improve the positive / negative symmetry of the light emission characteristics during AC drive by symmetrically configuring both sides of the light emitting layer, and consider the function of maintaining the dielectric breakdown voltage, which is the role of the light emitting layer dielectric layer. Since it is not necessary to do so, the film thickness may be small.

This thin film insulator layer has a resistivity of 10
^It is preferably ⁸ Ω · cm or more, particularly about 10 ¹⁰ to 10 ¹⁸ Ω · cm. A substance having a relatively high relative permittivity is preferable, and the relative permittivity ε is preferably ε =
It is 3 or more. As the constituent material of this thin film insulator layer,
For example, silicon oxide (SiO ₂ ), silicon nitride (Si
N), tantalum oxide (Ta ₂ O ₅ ), yttrium oxide (Y ₂ O ₃ ), zirconia (ZrO ₂ ), silicon oxynitride (SiON), alumina (Al ₂ O ₃ ), and the like can be used. As a method for forming the thin film insulator layer, a sputtering method, a vapor deposition method, or a CVD method can be used. The thickness of the thin film insulator layer is preferably 10 to 1000 nm, particularly preferably 20 to 20 nm.
It is about 0 nm.

For the transparent electrode layer, an oxide conductive material such as ITO, SnO ₂ (nesa film), ZnO-Al or the like having a film thickness of 0.2 μm to 1 μm is used. As a method of forming the transparent electrode layer, a known technique such as a vapor deposition method other than the sputtering method may be used.

Although the EL element described above has only a single light emitting layer, the EL element of the present invention is not limited to such a structure, and a plurality of light emitting layers may be laminated in the thickness direction. Alternatively, a configuration may be adopted in which different types of light emitting layers (pixels) are combined in a matrix and arranged in a plane.

[0089]

[Embodiment 1] E having a structure as shown in FIGS.
An L panel was produced. That is, when a thick film dielectric is formed by screen printing, a substrate having a width of 3 mm from the outer periphery of the thick film dielectric as a bank for sealing in the upper layer, a thickness after firing of 10 μm, and a sealing thickness The height of the embankment from 30
The thick film dielectric was printed and fired to a thickness of μm. Then, an inorganic EL structure was created.

The inorganic EL structural body (hereinafter referred to as a panel) completely formed on the alumina substrate and the sealing glass were washed with UV ozone, and then the sealing resin was applied to the outer peripheral portion of the sealing glass with a single stroke using a dispenser.

Resin: UV resin (6000 mJ / cm ² curing,
Viscosity 1900pa.s) Dispense: Nozzle inner diameter 0.6mm, Gap 250μ
m, speed 2mm / S coating position: 1mm inside the glass periphery, resin height after leveling 200μm

After applying the sealing resin, the panel is placed in the vacuum chamber (the inorganic EL structure faces the glass side),
The sealing glass was set up (the resin-coated surface was faced to the panel side).

Then, the evacuating and the N ₂ purging were repeated (5 times) to create an N ₂ dry atmosphere. Then -80k
The pressure was reduced to Pa, and the panel and the sealing glass were fixed with a 100 μm gap.

The panel and the sealing glass are sealed with resin, and the space pressure thereof is about -40 kPa, which is higher than the pressure inside the chamber. If left as it is, there is a danger that the sealing resin will break, so a leak in the chamber was started within 1 second of application and the pressure was returned to atmospheric pressure in 15 seconds.
After that, UV irradiation was performed to complete the sealing process.

As a comparative example, a sample in which a bank is not formed on the thick dielectric layer was also prepared.

Each EL panel obtained was stored under the conditions of storage at 60 ° C.
The brightness was measured after storage at -90% for 1000 hours, and the change rate was calculated to evaluate the stability. The results are shown in Table 1.

[0097]

[Table 1]

In the comparative sample, the coating width of the sealing resin was not stable, and the same result as the invention sample was obtained in the sample 1 of 2.0 mm, but the sample having the fluctuation of 1.0 to 2.5 mm. In No. 2, the brightness after storage is lowered.

Example 2 An EL device having a structure as shown in FIGS. 3 and 4 was produced. That is, in Example 1, the thick film dielectric was formed without forming the sealing bank on the display part thick film dielectric layer, and the thickness (seal thickness) after firing was 2
It was set to 0 μm. Next, as shown in FIG. 5, a tape was attached to a region required as a seal width when the flattening layer precursor solution was spin-coated. Specifically, by sticking a tape having a thickness of 80 μm, a pool of the planarizing layer precursor solution was formed in the step portion. Here, the planarization layer precursor solution using a sol-gel solution of _{PZT (= Pb (Zr x Ti} 1-x) 3).

By peeling off the tape during firing and firing, the portion where the planarizing layer precursor solution was accumulated was thickened. Although a crack was formed, a bank of about 10 μm could be formed in the part where the pool was formed.

After the sealing glass was washed with UV ozone, the sealing resin was applied to the outer peripheral portion of the sealing glass with a single stroke using a dispenser.

Resin: UV resin (6000 mJ / cm ² curing,
Viscosity 1900pa.s) Dispense: Nozzle inner diameter 0.6mm, Gap 250μ
m, speed 2mm / S coating position: 1mm inside the glass periphery, resin height after leveling 200μm

After applying the sealing resin, the panel is placed in the vacuum chamber (the inorganic EL structure is directed to the glass side).
The sealing glass was set up (the resin-coated surface was faced to the panel side).

Then, evacuation and N ₂ purging were repeated (5 times) to create an N ₂ dry atmosphere. Then -80k
The pressure was reduced to Pa, and the panel and the sealing glass were fixed with a 100 μm gap.

The panel and the sealing glass are sealed with resin, and the space pressure thereof is about -40 kPa, which is higher than the pressure inside the chamber. If left as it is, there is a danger that the sealing resin will break, so a leak in the chamber was started within 1 second of application and the pressure was returned to atmospheric pressure in 15 seconds.
After that, UV irradiation was performed to complete the sealing process.

When the obtained sample was evaluated in the same manner as in Example 1, almost the same result was obtained.

[Embodiment 3] In Embodiment 1, the vacuum degree of the vacuum chamber at the time of performing the sealing operation is adjusted so that the pressure in the sealed space after sealing is about −10 kPa, about atmospheric pressure, 12
Samples 11, 12, and 13 having a pressure of about 0 kPa were prepared,
A thermal shock test and a high temperature and high humidity storage test were conducted.

Here, in the thermal shock test, cooling and heating, which are held at −45 ° C. and 85 ° C. for 30 minutes each, were repeated and evaluated in 300 cycles. At this time, 3% or more without change in brightness was rated as ⊚, 5% or more without brightness change was rated as ○, 10% or more without brightness change as Δ, and less than that was rated as X. Further, in the high temperature and high humidity storage test, the change in brightness under the environment of 60 ° C-90% was obtained. At this time, 3 in 1000 hours
% No change in brightness was rated as ⊚, 5% or more did not change in brightness, and 10% or more did not change in brightness as Δ, and less than that as x. The results are shown in Table 2.

[0109]

[Table 2]

From Table 2, it can be seen that the sample in which the pressure in the sealed space is atmospheric pressure or negative pressure is excellent in the thermal shock test and the high temperature and high humidity storage test.

[0111]

As described above, according to the present invention, it is possible to suppress the fluctuation of the seal width and the thickness due to the application variation of the adhesive resin in a simple working process, and to securely seal the EL panel with the adhesive resin, and to manufacture the same. A method can be provided.

Further, it is possible to provide an EL panel and a method for manufacturing the same, which can eliminate the increase in the number of steps due to the incorporation of spacers and the formation of columns, and can improve the deterioration of the adhesive force due to the incorporation of spacers.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a first embodiment of an EL panel of the present invention.

FIG. 2 is a schematic sectional view showing a first embodiment of an EL panel of the present invention.

FIG. 3 is a schematic plan view showing a second embodiment of the EL panel of the present invention.

FIG. 4 is a schematic cross-sectional view showing a second embodiment of the EL panel of the present invention.

FIG. 5 is a schematic cross-sectional view showing another configuration example of the second embodiment of the EL panel of the present invention.

FIG. 6 is a schematic cross-sectional view showing the manufacturing process of the second embodiment of the EL panel.

FIG. 7 is a schematic cross-sectional view showing the manufacturing process of the second embodiment of the EL panel.

FIG. 8 is a schematic cross-sectional view showing the manufacturing process of the second embodiment of the EL panel.

FIG. 9 is a schematic cross-sectional view showing the basic structure of an EL element of the present invention.

[Explanation of symbols]

1 substrate 2 EL structure 3 Adhesive resin stop structure (bank) 4 Sealing resin 5 Sealing plate 6 Flattening layer 6a Adhesive resin stop structure

Claims (8)

[Claims] 1. A substrate, an EL structure laminated on the substrate, a sealing plate disposed on the EL structure with a predetermined gap, and the sealing plate fixed on the substrate. And an encapsulating adhesive resin that seals the EL structure together, and an adhesive resin stopper structure that contacts the encapsulating adhesive resin with a part of the constituent members of the EL structure and regulates the encapsulating adhesive resin. An EL panel that has a body. 2. The EL structure includes a substrate having at least an electrical insulation property, a first electrode, a thick film dielectric layer, a light emitting layer, a thin film dielectric layer, and a second electrode, which are sequentially stacked. The EL panel according to claim 1, wherein 3. The EL panel according to claim 2, wherein the adhesive resin stopping structure is made of the same material as the thick film dielectric layer. 4. The EL structure comprises at least an electrically insulating substrate, a first electrode, a thick film dielectric layer, a planarizing layer,
The EL panel according to claim 1, wherein the light emitting layer, the thin film dielectric layer, and the second electrode layer are sequentially laminated. 5. The EL panel according to claim 4, wherein the adhesive resin stopping structure is made of the same material as the flattening layer. 6. The EL element according to claim 1, wherein the space in which the EL structure is sealed has an atmosphere equal to or depressurized from atmospheric pressure. 7. A substrate on which an EL structure is laminated is housed in a decompression tank, the pressure in the decompression tank is reduced to a predetermined pressure lower than atmospheric pressure, and then a predetermined amount surrounding the EL structure on the substrate. A method for manufacturing an EL panel, in which the sealing adhesive resin is applied with a single stroke to the area of (1), the sealing plate is fixed, and then the reduced pressure body is released to take out the substrate from the reduced pressure tank. 8. The method of manufacturing an EL panel according to claim 7, wherein the space in which the EL structure of the substrate taken out from the decompression tank is sealed has an atmosphere equal to or depressurized from atmospheric pressure.