JPH11329717A - Color el panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color EL(electroluminescence) panel capable of preventing moisture from penetrating into its interior and hence having excellent long-term reliability. SOLUTION: In a color EL panel 30, a frame-like projecting part 41 is formed on a substrate 35 for a thin film EL device 31, for example with frit glass, a strip-shaped lower electrode 36 is formed on this substrate 35, a lower insulating layer 37, a light emitting layer 38, and an upper insulating layer 39 are formed on this lower electrode 36, and a strip shaped upper electrode 40 is formed on a structure thus made so as to be perpendicular to the lower electrode 36. A color filter 32 and a spacer 33 are formed on a translucent substrate 34, and the translucent substrate 34 and the substrate 35 are bonded together through an adhesive layer 44, such as of epoxy resin, on a convex part 41 so that the color filter 32 faces the thin film EL device 31. Finally, a silicone oil is injected and a panel is sealed to finish the color EL panel 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color EL panel which performs multicolor display by combining a thin film EL element which generates electroluminescence (electroluminescence) light and a color filter by applying an AC voltage.

[0002]

2. Description of the Related Art Compared with a liquid crystal display device, an EL panel is a self-luminous display device in which the entire device can be constituted by solid-state elements, has high contrast, and is excellent in display recognition.
Since it has many characteristics that cannot be obtained with a liquid crystal display device, it has been widely studied, and research on colorization has been promoted.

As a technology for realizing a color EL panel,
In Japanese Patent Publication 3-77640, red, green, and blue (hereinafter, referred to as
There is disclosed a technique of forming light-emitting layers showing three primary colors of “R, G, and B” in parallel. In order to adopt this technology, a high-luminance light-emitting layer that emits each of the R, G, and B colors is necessary. However, since a material that exhibits sufficient luminance to constitute a display has not been found, it is difficult to use a light-emitting layer. Has not yet been put to practical use.

As another method, there is a technique in which white light including three primary colors from a light emitting layer is spectrally extracted by using R, G, and B color filters.

The technique disclosed in Japanese Patent Application Laid-Open No. 64-40887 is a technique in which a color filter is formed directly on the upper surface of an upper electrode. Since a thin film EL element is formed by laminating a plurality of thin films by a sputtering method, a defect such as a pinhole is caused in an insulating layer when the thin film is formed.
Therefore, when a high voltage is applied to drive the thin film EL element, dielectric breakdown occurs and a minute discharge occurs. The micro-discharge generates heat and sparks, causing a problem that the color filter made of an organic substance formed on the upper electrode is altered or destroyed by the heat.

The color EL panel disclosed in Japanese Patent Application Laid-Open No. 64-40888 has a thin-film EL element having a structure for extracting EL light from the upper electrode side and a color filter for splitting the EL light to obtain multicolor light emission. And a gap between the upper electrode and the color filter.

FIG. 8 is a sectional view showing such a color EL panel 1. As shown in FIG. The color EL panel 1 includes a thin-film EL element 28 and a light-transmitting substrate 10, and the thin-film EL element 28
A lower electrode 4 made of ITO (indium tin oxide) or a metal, a lower insulating layer 5, an EL light-emitting layer 6, an upper insulating layer 7, and a light-transmitting upper The electrodes 8 are arranged in this order. The upper electrode 8 and the lower electrode 4 have a plurality of strips, and are arranged substantially orthogonal to each other. By applying an AC voltage between the upper electrode 8 and the lower electrode 4, the light emitting layer 6 at the intersection of the upper electrode 8 and the lower electrode 4 emits light, thereby enabling display. After forming the light emitting layer 6 or the upper insulating layer 7 to improve the crystallinity, the light emitting layer 6 is subjected to an annealing treatment (heat treatment) in a vacuum or an inert gas.

The color EL panel 1 includes a substrate 3 for a thin film EL element 2 and an R.G.
A light-transmitting substrate 10 on which a color filter 9 having three primary colors such as B is formed, and the light-transmitting substrate 10 is bonded to the light-transmitting substrate 10 via a sealing portion 11 such as an epoxy resin; Between them, silicon oil is filled and sealed to prevent moisture from entering the EL element surface. At present, many of the color EL panels 1 which have been widely developed and researched include the thin-film EL elements 28 having the double insulating structure as described above.

The substrate 1 and the light-transmitting substrate 10 are connected to a sealing portion 11
The upper electrode 8 and the color filter 9 are bonded to each other with a gap of a certain distance or more provided therebetween, so that sparks, heat, and the like due to dielectric breakdown can be prevented from affecting the color filter to some extent.

As described above, the upper electrode 8 of the thin film EL element 28
It is necessary to keep the gap distance between the color filter 9 provided on the light-transmitting substrate 10 and the sealing portion 11
Thickness is 2 to 10μ adopted in monochrome EL panel
It is several times thicker than m. As a result, the amount of permeation and penetration of moisture which causes deterioration of the life of the EL panel through the sealing portion 11 increases, and there is a problem that the life characteristic, which is one of the features of the color EL panel, is reduced.

In order to solve such a problem, Japanese Patent Application Laid-Open No. 8-16227 discloses a method of reducing the thickness of the sealing portion by interposing a glass frame spacer in the sealing portion.

FIG. 9 shows an E having a glass material spacer 20.
FIG. 3 is a cross-sectional view illustrating an L panel. EL panel 15
A light-transmitting substrate 18 is bonded to a substrate 16 on which an EL element 17 is provided via a sealing portion 19, and the substrate 16 and the light-transmitting substrate 18 are bonded.
Is filled with silicon oil 23. In the sealing portion 19, since the glass frame spacer 20 having excellent moisture-proof properties is interposed between the adhesive layers 20 and 21 made of epoxy resin, the thickness of the adhesive layer is substantially reduced.

[0013]

The above-mentioned EL panel 1
In No. 5, the thickness of the adhesive layer of the sealing portion 19 is reduced, but the number of the adhesive layers 21 and 22 increases in two places. Moisture is transmitted through the interface between the adhesive layers 21 and 22 and the substrates 17 and 18 or the glass frame spacers 20 in particular.
Even if the thickness of the adhesive layers 21 and 22 is reduced,
However, there is a problem that a significant improvement effect cannot be obtained by increasing the number to two places.

An object of the present invention is to provide a color EL panel having long-term reliability by reducing penetration of moisture.

[0015]

According to the present invention, there is provided a thin film EL device in which a lower electrode, an EL light emitting layer and an upper electrode are formed on an electrically insulating substrate, and a color filter in which a color filter facing the upper electrode is provided. A light-emitting substrate, wherein the EL light emitted from the upper electrode of the thin-film EL element is emitted from the light-transmitting substrate through a color filter, wherein at least one of the substrate and the light-transmitting substrate has a projection. Is formed, and a substrate facing the convex portion is bonded via an adhesive layer.

According to the present invention, by applying an AC voltage between the upper electrode and the lower electrode, the light emitting layer at the intersection of the upper electrode and the lower electrode emits EL light, and transmits light through a color filter. EL light is emitted from the conductive substrate, and color display is performed. The substrate and the light-transmitting substrate face each other on the convex portion formed on the one substrate in order to provide an interval such that scattering substances generated due to dielectric breakdown of the thin film EL element do not reach the color filter. The substrate is assembled by bonding through a bonding layer. As described above, since the substrate and the light-transmitting substrate are bonded via the protrusions and the bonding layer, the thickness of the bonding layer can be reduced while maintaining the space between the substrates. This can reduce the amount of moisture that penetrates and penetrates through the adhesive layer, and prevents the life of the color EL panel from deteriorating. Also, since the convex portion is formed on the substrate, unlike the EL panel which is bonded through the above-described glass frame spacer, only one bonding layer is required, so that the penetration of moisture due to the increase in the bonding layer can be prevented. Can be.

Further, the present invention is characterized in that the convex portion is formed in a frame shape. According to the present invention, by forming the convex portion in a frame shape, the distance between the light-transmitting substrate and the substrate can be made substantially constant, and the adhesive layer can be made constant.

Further, in the present invention, the convex portion is characterized in that the one substrate and the convex portion are integrally formed by etching a base material.

According to the present invention, the projection and the substrate can be integrally formed by etching the region of the base material other than the portion where the projection is formed. Since the projection is not separately attached, moisture does not intrude from the bonding portion, and the life can be prevented from deteriorating due to the penetration and penetration of moisture.

Further, the present invention is characterized in that the convex portion is formed of frit glass.

According to the present invention, a frit (glassy powder) is provided in a region of the substrate where the convex portion is to be formed, and is fired to form a convex portion made of frit glass on the substrate. Since the convex portion is formed on the substrate without using the adhesive as described above, it is possible to reliably prevent moisture from entering between the convex portion and the substrate. Further, since the convex portion is made of a glass material having excellent moisture resistance, the penetration and penetration of moisture can be effectively prevented.

The thickness of the adhesive layer of the present invention is 2 μm
It is characterized in that it is selected to be not less than 10 μm.

According to the present invention, since the thickness of the adhesive layer is selected to be not less than 2 μm and not more than 10 μm, intrusion of moisture from the adhesive layer can be prevented as much as possible. If the thickness of the adhesive layer exceeds 10 μm, the panel life is shortened due to the penetration and penetration of moisture, and if the thickness of the adhesive layer is less than 2 μm, the bonding is performed substantially only with the adhesive layer.
Since the resistance to distortion such as thermal stress is reduced, and the adhesion is reduced such that peeling is likely to occur, it is difficult to reliably seal and bond the projection and the substrate.

The height of the projection according to the present invention is 10 μm.
It is characterized in that it is selected to be not less than 50 μm.

According to the present invention, since the height of the convex portion is selected to be not less than 10 μm and not more than 50 μm, a color display can be performed clearly without sparks or heat due to dielectric breakdown affecting the color filter. Can be. If the height of the projection exceeds 50 μm, the gap between the upper electrode and the color filter becomes large, thereby causing a color shift phenomenon, making it impossible to perform clear color display, and the height of the projection being 10 μm. If it is less than the above, the gap between the upper electrode and the color filter becomes small, thereby affecting the color filter due to dielectric breakdown or the like.

Further, the thin film EL device of the present invention is characterized by having at least one or more insulating layers and at least one or more EL light emitting layers.

According to the present invention, since the EL element has one or more insulating layers and one or more EL light emitting layers, the three primary colors of R, G, and B are obtained by combining a plurality of light emitting layers. White light can be obtained.

Further, the present invention is characterized in that the EL device is an organic EL device. According to the present invention, the thin film EL
Since the device is an organic EL device, it is possible to reduce the operating voltage and to realize a wide range of emission colors from the viewpoint of the diversity of organic materials.

Further, the present invention is characterized in that the extraction electrode formed from the inside to the outside with respect to the frame-shaped projection and the inside end is connected to the upper and lower electrodes is formed by a mask evaporation method. .

According to the present invention, since the extraction electrode is formed by a mask vapor deposition method using a vapor deposition mask, it is caused by unevenness in resist coating which occurs when patterning is performed through a convex portion in a normal photo process. It is possible to prevent the occurrence of unevenness in the thickness of the resist pattern and the disconnection or short circuit of the electrode pattern after the etching, which can significantly improve the production yield of the EL panel.

[0031]

FIG. 1 is a sectional view of a color EL panel 30 according to a first embodiment of the present invention, and FIG. 2 is a plan view of a thin-film EL element 31 of the color EL panel 30.
The color EL panel 30 includes a light-transmitting substrate 3 on which a thin-film EL element 31, a color filter 32, and a spacer 33 are formed.
4 is included. The thin film EL element 31 is formed by arranging a lower electrode 36, a lower insulating layer 37, an EL light emitting layer 38, an upper insulating layer 39, and a translucent upper electrode 40 in this order on an electrically insulating substrate 35. Is done.
The lower electrode 36 is in the form of a plurality of strips parallel to each other, and the same applies to the upper electrode 40.
Are arranged substantially orthogonal to each other.

The substrate 35 is made of, for example, OA manufactured by NEC Corporation.
-2 or the like or a heat-resistant ceramic, and a convex portion 41 is formed in a rectangular frame shape on a peripheral portion on one surface. The method of forming the convex portion 41 is as follows.
A paste obtained by adding a vehicle to a frit (glassy powder) such as S-1301 and kneading it is printed in a frame shape on one surface of the substrate 35 by screen printing.
Preliminary baking is performed at 380 ° C. for about 15 minutes.
It is formed by performing baking for 10 minutes in a nitrogen atmosphere at ° C.

The shape of the projection 41 is, for example, a width W1 of 5 mm, a height H1 of 10 μm or more and 50 μm
It is selected as follows, and in the present embodiment, it is selected to be 20 μm.

After the projections 41 are formed on the substrate 35, a high melting point metal such as Ta, Mo, W or ITO or ITO is formed on the substrate 3 by a thin film forming method such as a sputtering method, an electron beam evaporation method and a spray method. A film having a thickness of 100 to 400 nm is formed, and a band-shaped lower electrode 36 is formed by a photoetching process. Almost the entire surface of the substrate 35 covering the lower electrode 36 is made of SiO ₂ ,
SiN, a lower insulating layer 37 made of Ta ₂ O ₅ or the like, and SrTiO ₃ is formed to a thickness of 200 to 500 nm.

The EL light emitting layer 38 has a substrate temperature of 450-65.
Maintain at 0 ° C. and add 0.05-0.3 wt% of Ce to SrS.
Using a SrS: CeN pellet fired by adding N as an evaporation source, a film is formed to a thickness of 800 to 1500 nm on the lower insulating layer 37 by an electron beam evaporation method, and the substrate temperature is kept at 200 to 300 ° C. 0.2-0.6 for ZnS
Using a ZnS: Mn pellet added with wt% Mn as an evaporation source, 200 to 500 nm by electron beam evaporation.
It is formed by laminating to a film thickness of.

The upper insulating layer 39 is formed on the EL light emitting layer 38 in the same manner as the lower insulating layer 37. EL deposited
In order to improve the crystallinity of the light emitting layer 38, after forming the upper insulating layer 39, a heat treatment is performed at a temperature of 600 to 650 ° C. in a vacuum for 1 to 2 hours.

The upper electrode 40 is formed by forming a transparent electrode of ITO or ZnO: Al, Ga to a thickness of 100 to 500 nm on the upper insulating layer 39 by a thin film forming method, and is formed with the lower electrode 36 by a photo etching process. The upper electrode 40 is formed in a plurality of strips in a direction substantially orthogonal to the upper electrode 40. Through the above steps, the thin film EL element 31 is completed.

By applying an AC voltage between the lower electrode 36 and the upper electrode 40 of the thin film EL element 31, the EL light emitting layer 38 at the intersection of the lower electrode 36 and the upper electrode 40 emits light. In the EL light emitting layer 38 in which SrS: Ce and ZnS: Mn are stacked as described above, SrS: Ce emits blue-green light and ZnS: Mn emits yellow-orange light. Can be. The intersection area between the lower electrode 36 and the upper electrode 40 corresponds to a picture element area.

The color filter 32 disposed to face the thin-film EL element 31 is, for example, a CR manufactured by Fuji Hunt.
-7001, a red filter R1 made of Fuji Hunt CG-7001, and a blue filter B1 made of Fuji Hunt CB-7001. The filters R1, G1, and B1 are formed in a plurality of strips in parallel in this order by a photolithography method on a translucent substrate 34 made of glass or the like. One band-shaped filter 32 is provided corresponding to one band-shaped upper electrode 40.

The thin-film EL element 31 and the light-transmitting substrate 34 on which the color filter 32 is formed are arranged to face each other with a spacer 33 interposed therebetween. At this time, one filter 32 is arranged so as to face one upper electrode 40. The spacer 33 is made of, for example, a material in which a black dye is contained in a photo-curable resin, and the filters R 1, G 1, and B of the color filter 32 are formed by employing such a spacer 33.
1 can be prevented, and the contrast is improved.

Such a spacer 33 is made of a material obtained by adding a black dye to a photocurable resin by 10 μm by a spin coating method.
It is formed on the color filter 32 to a thickness of m, and is formed in a band shape with a width of 30 μm by a photo process.

A concave portion 42 is formed in the translucent substrate 34 provided with the color filter 32 to capture moisture invading from the outside and fill with a moisture absorbing material 43 for preventing the occurrence of moisture absorption and separation of the EL element. The shape of the concave portion 42 has a width W2
Is 3 to 10 mm, the depth T1 is 0.3 to 1 mm, and is formed in a square frame shape.

Thereafter, the color EL panel 30 is assembled by bonding the thin film EL element 31 and the light-transmitting substrate 34 having the color filter 32 such that the color filter 32 faces the color EL panel 31. At this time, an adhesive layer 44 of epoxy resin or the like in which a small amount of a gap material such as a glass rod is mixed is interposed between the upper end of the projection 41 and the light-transmitting substrate 34 and bonded. Thereafter, silicone oil is injected and sealed between the substrates, that is, the space between the upper electrode 39 and the color filter 32 and the peripheral space between the projection 41 and the light emitting layer 38 to perform oil sealing. Silica gel is mixed in this silicone oil as a moisture absorbing material.

The gap H2 between the color filter 32 and the upper electrode 40 has a great effect on the viewing angle dependence of the panel.
A high viewing angle of 0 ° is ensured. Color E with high definition
In the L panel, the interelectrode width W3 is often set to 50 μm or less, and the gap width H is set except for a special large panel.
2 is desirably set to 30 μm or less, and the gap H2 needs to be 5 μm or more in order to sufficiently prevent the influence of dielectric breakdown of the upper electrode 40. Therefore, the gap H2 is preferably selected in a range of 10 μm or more and 20 μm or less.

FIG. 3 is a graph showing the result of simulating the relationship between the thickness t of the adhesive layer of the color EL panel 30 and the life of the panel during storage by an accelerated test. In addition to the thickness t of the adhesive layer, the panel life is increased by the seal width of the adhesive layer 44, the water permeability of the epoxy resin used, the concave portion 42 formed in the light-transmitting substrate 34, and the amount of silica gel mixed in the silicon oil. Therefore, the conditions other than the adhesive layer thickness t are such that the adhesive is H. C. LC-200 made of epoxy resin, the seal width was 3.5 mm, the width W2 of the concave portion 42 filled with the hygroscopic material 42 was 3.5 mm, the depth T1 was 0.6 mm, and the silicon oil filled was 25 wt%.
% Of silica gel mixed with a mixture of silica gel and silicon oil.

As is clear from the graph, the thickness of the adhesive layer t
The panel life (storage life) improves as the value decreases, and a panel life of 100,000 hours or more can be obtained especially when the thickness of the adhesive layer is 10 μm or less. Therefore, the thickness of the adhesive layer is 10 μm
By doing so, the reliability as a display for factory automation (FA), which is characterized by maintenance-free color EL panels, can be ensured.

The protrusion 41 is not provided, and the thickness t of the adhesive layer is 25 μm.
Although the conventional color EL panel prepared in the above has poor life performance and can obtain a panel life of only 60,000 hours, the color EL panel 30 of the present embodiment has a height H1 = 20 μm.
By providing the m convex portions 41, the substrate interval H3 = 25
The thickness t of the adhesive layer can be reduced to 5 μm while maintaining the thickness at μm, whereby a long life of about 150,000 hours can be achieved.

Also, such a color EL panel 30
By splitting the white EL light with the color filters R1, G1, and B1, it is possible to emit multicolor light based on three primary colors. Even after the accelerated aging equivalent to 30,000 hours of actual driving, the color filter 32 does not deteriorate due to the influence of dielectric breakdown or the like, and does not undergo moisture absorption and peeling caused by intrusion of moisture. It has been confirmed that high display quality is maintained over the period.

FIG. 4 shows a color E according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view showing an L panel. The components corresponding to the color EL panel 30 shown in FIG. 1 are denoted by the same reference numerals. Thin-film EL element 51 of color EL panel 50
The substrate 52 and the convex portion 53 are integrally formed by etching the base material. For example, after etching a mask for etching resistance in a frame shape on a surface of a glass substrate such as OA-2 manufactured by Nippon Electric Glass, the surface of the glass substrate is etched with an etching solution containing hydrofluoric acid (hydrofluoric acid) as a main component. Is etched to a depth of 25 μm. As a result of this processing, the unetched portion remains as a projection 53 having a height of 25 μm, and the projection 53 is integrally formed on the substrate 52.

On such a substrate 52, a lower electrode 36, a lower insulating layer 37, a light emitting layer 38, and an upper insulating layer 39 are formed in the same manner as in the manufacturing process of the thin film EL element 31 of the color EL panel 30 of the first embodiment. It is formed. Such a thin film EL
When an AC voltage is applied to the lower electrode 36 and the upper electrode 40 of the element 51, the intersection emits white light.

A color filter 55 facing the thin-film EL element 51 is formed by forming a blue filter B2 such as CB-7001 manufactured by Fuji Hunt on a light-transmitting substrate 54 such as glass, including a light-emitting picture element region and a space between electrodes on both sides thereof. It is formed in the shape of a strip with a width.
Next, the red filter R2 of Fuji Hunt CR-7001
Are formed in a stripe shape with a similar width. At this time, FIG.
As shown in the figure, a blue filter B2 is provided between the electrodes on one side.
A region where the red filter R2 overlaps is formed above.

Further, when the green filter G2 of the CG-7001 manufactured by Fuji Hunt is similarly formed, the red filter R1, the green filter G2 and the blue filter B2 are formed on both sides thereof.
And a green filter G2 overlap region is formed. In addition,
The order of forming these three types of color filters B2, R2, and G2 is not limited to the above-described order, and may be another order.

As a result, external light transmitted through the color filter 55 is reflected by the lower electrode 31 and transmitted again through the color filter 55 to the display surface side.
The reflected light is almost absorbed in the region where the different types of color filters overlap, and a blackened film having an effect similar to a black matrix is obtained. The contrast is improved and the visibility is improved.

A spacer 56 is formed on the color filter 38. The formation position of this spacer 56 is 50 μm
Between the upper electrodes 40 having the inter-electrode width W3.
The photocurable resin is formed at a position separated by a distance W4 of 0 to 10 μm, and a photocurable resin is manufactured to a thickness of 10 μm. It is formed in a belt shape. As described above, the spacers 56 correspond to the light emitting picture element regions and are formed at intervals in the longitudinal direction, so that the conductance at the time of injecting the silicon oil increases, that is, the resistance decreases,
The oil injection time is shortened and the productivity is improved. Also,
As described above, since the contrast is improved in the region where the color filters overlap, the spacer 56 does not need to be made of a black material as used in the first embodiment.

Similarly to the light-transmitting substrate 34 of the first embodiment, the light-transmitting substrate 54 is made of a moisture-absorbing material for capturing moisture that has entered from the outside and preventing the thin-film EL element 51 from absorbing and separating. A concave portion 42 for filling 43 is formed in a frame shape.

Thereafter, the light transmitting substrate 54 on which the thin film EL element 51, the color filter 55 and the spacer 56 are formed
Are bonded via an adhesive layer 44 such as an epoxy resin mixed with a small amount of a gap material such as a glass rod.
Silicon oil mixed with silica gel as a moisture absorbing material is injected between the four and sealed, and an oil seal is performed. Also in the present embodiment, as described in detail in the first embodiment, of the structure having a substrate interval H3 = 30 μm from one surface of the substrate 52 of the thin film EL element 51 to one surface of the light-transmitting substrate 54, Since the height of the portion 53 is H1 = 25 μm, the adhesive layer thickness t of the epoxy resin adhesive layer 44 is 5 μm, which makes it possible to achieve a practical seal life.

FIG. 5 is a sectional view showing a color EL panel 60 according to a third embodiment of the present invention. The components corresponding to the color EL panel 30 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals.

The feature of this embodiment is that the thin-film EL element 61 is an organic EL element. The thin-film EL element 61
The convex portion 41 is formed in a frame shape on the substrate 35 by the method described in detail in the first embodiment, and the lower electrode 62 is first formed thereon as a lower electrode 62.
A metal electrode such as i-Al or Mg-Ag is formed in a plurality of strips. An electron transport layer 63 is formed on the lower electrode 62.
To form 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole to a thickness of 40 to 80 nm by a resistance wire heating method.

Further, on the light emitting layer 64, 1, 1
-Di (p-methoxyphenyl) -4,4-diphenylbutadiene is formed into a film having a thickness of 10 to 30 nm by a resistance wire heating method. On the light-emitting layer 53, as a hole transport layer 65, bis-di (p-tolyl) aminophenyl-1,1-cyclohexane is formed to a thickness of 40 to 80 nm by a resistance wire heating method. Finally, as the upper transparent electrode 66, ITO
A thin film EL element 61 composed of an organic EL element in which electrodes are formed in a plurality of strips in a direction intersecting with the lower metal electrode 62 by a film forming method such as a sputtering method to a thickness of 100 to 300 nm.
Is completed.

The thin film EL element 61 includes upper and lower electrodes 62,
Light is emitted in white by passing a current between 66. In addition,
The structure of the organic EL element is not limited to the example of the present embodiment, and any organic EL element that emits light including emission spectra of the three primary colors R, G, and B can be adopted.

The color filter 32 is formed on the light-transmitting substrate 34 as described in detail in the first embodiment, and a plurality of black spacers 33 are formed on the color filter 32. Further, the translucent substrate 34 has a moisture absorbing material 4
The recess 42 filled with 3 is formed in a frame shape.

After that, the light transmitting substrate 34 and the thin film EL element 31 are
And a substrate 35 is bonded via an adhesive layer 44 such as epoxy resin mixed with a small amount of a gap material such as a glass rod,
Silicon oil mixed with silica gel as a moisture absorbing material is injected and sealed between the substrates 35 and 34 to perform oil sealing.

The color EL panel 60 of the present embodiment, like the color EL panel 30 of the first embodiment, splits white EL light with the R1, G1, and B1 color filters to provide a multi-color based on three primary colors. Color light emission is possible. Also in the present embodiment, similarly to the first embodiment, the convex portions 4 are formed.
1, the thickness t of the adhesive layer can be reduced, so that even after accelerated aging equivalent to 30,000 hours of actual driving, the color filter is not affected by dielectric breakdown or the like for a long time without being deteriorated. It has been confirmed that high display quality is maintained.

FIG. 6 is a sectional view showing a color EL panel 69 according to a fourth embodiment of the present invention, and FIG.
FIG. 9 is a plan view of a thin-film EL element of an L panel. As in the color EL panel 50 of the second embodiment, the substrate 70 of the thin film EL element 82 of the color EL panel 69 is formed by patterning an etching mask in a frame shape on a glass base material such as OA-2 manufactured by NEC Corporation. Thereafter, the surface of the glass substrate is etched to a depth of 25 μm with an etching solution containing hydrofluoric acid as a main component. As a result of this processing, the unetched portion becomes the convex portion 81 having a height H1 of 25 μm, and the substrate 70 and the convex portion 81 are integrally formed.

On this substrate 70, as a lower electrode 71,
ITO, Ta, Mo or W by various thin film forming methods such as a sputtering method, an electron beam evaporation method or a spray method.
After forming a high melting point metal such as 100 to 400 nm in thickness, the lower electrode 71 is formed by patterning into a plurality of strips by a photoetching process. As the lower insulating layer 72 on the lower electrode 71, for example,
An insulating film such as iO ₂ , SiN, Ta ₂ O ₅ , SrTiO ₃ is formed to a thickness of 200 to 500 nm.

The light-emitting layer 73 is formed by, for example, electron beam evaporation, maintaining the substrate temperature at 200 to 300 ° C., adding 0.1 to 4.0 wt% of PrF ₃ to ZnS, and sintering ZnS.
S: Using a PrF ₃ pellet as an evaporation source, an electron beam evaporation method is used to form a film having a thickness of 300 to 800 nm, and the substrate temperature is maintained at 200 to 300 ° C .;
A ZnS: TbF ₃ pellet to which 0 wt% of TbF ₃ is added is used as an evaporation source by an electron beam evaporation method to form a ZnS: TbF ₃ pellet.
It is formed to have a thickness of nm.

The upper insulating layer 74 is formed by the same process as that for forming the lower insulating layer 72. After the formation of the upper insulating layer 74, 600 to 6 mm in vacuum is applied to improve the crystallinity of the deposited light emitting layer 73.
Heat treatment is performed at 50 ° C. for 1 to 2 hours. Finally, the upper electrode 7
5, a transparent electrode made of ITO or ZnO: Al, Ga is formed to a thickness of 100 to 500 nm.
Forming a plurality of strips in a direction orthogonal to
2 is completed.

In this embodiment, the thin film EL element 82
The lower electrode 72 and the upper electrode 75 are formed inside a frame-shaped protrusion 81 formed on the substrate 70. Therefore, the lower and upper electrodes 71, 7 of the thin film EL element 82
5 is connected to an extraction electrode 80 for connecting to a drive system such as TAB (tape automated bonding). One end of the extraction electrode 80 is connected to the lower or upper electrodes 71 and 75 inside the projection 81, and the other end extends to the periphery of the substrate 70 via the projection 81 and is formed in a band shape.

The extraction electrode 80 is formed by a mask evaporation method. That is, the extraction electrode 80 to be formed
Using a stencil mask made of metal or Si having a hole penetrating in the form of, for example, it is positioned and superimposed on the substrate 70, and one end of the extraction electrode 80 is connected to the lower or upper electrode 7.
Vapor deposition is carried out so as to overlap the ends of the first and the 74th.

In the mask vapor deposition method, even if there is a certain degree of unevenness, the metal can be vapor-deposited only on a necessary portion. Therefore, even if the convex portion 81 is formed on the substrate 70 as in the present embodiment, it is accurate. It is possible to deposit the extraction electrode 80 on the substrate. In addition, it is possible to prevent the occurrence of a non-uniform portion of the resist pattern thickness due to the unevenness of the resist coating caused when the patterning is performed by the normal photo process, and the disconnection or short circuit of the electrode pattern after the etching caused by the unevenness. Thus, the production yield of the color EL panel can be remarkably improved.

The intersection of the color EL panel 82 emits light when an AC voltage is applied to each of the extraction electrodes 80 of the lower electrode 71 and the upper electrode 75. Z used in this embodiment
The laminated light emitting layer 73 of nS: PrF ₃ and ZnS: TbF ₃
ZnS: PrF ₃ emits blue-green and red light,
S: Since TbF ₃ emits green light, white light is obtained as the emission color.

The color filter 78 facing the thin-film EL element 82 is composed of a blue filter B3 of CB-7001 manufactured by Fuji Hunt, a green filter G3 of CG-7001 manufactured by Fuji Hunt, and a color filter G3 of Fuji Hunt on a transparent substrate 79 made of glass or the like. Each of the red filters R3 of CR-7001 manufactured is formed in a strip shape with the same width as the upper electrode 75. Next, a black filter BK of CK-7001 manufactured by Fuji Hunt is formed at a position between the color filters B3, R3, and G3, that is, at a position between the upper electrodes 75. By providing the black filter BK between the upper electrodes 75 in this manner, the contrast is improved, so that the visibility is improved.

Thereafter, a particle size of 20 to
A suitable amount of spacers 77 such as plastic beads of 25 μm is scattered, and a transparent substrate 79 on which a color filter 78 is formed is bonded through an adhesive layer 76 of epoxy resin or the like in which a small amount of a gap material such as a glass rod is mixed. = 5 μm, and a silicone oil mixed with silica gel as a moisture absorbing material is injected and sealed between the substrates 70 and 79, and an oil seal is performed to complete the color EL panel 69.

Also in this embodiment, as described in detail in the first embodiment, the protrusions 81 in the substrate gap H3 = 30 μm.
Is 25 μm, so that the thickness t of the adhesive layer is 5 μm, whereby a practical seal life can be achieved.

[0075]

According to the first aspect of the present invention, the thin film E
A convex portion is formed on at least one of the substrate of the L element and the light-transmitting substrate, and the opposing substrate is bonded to the convex portion via an adhesive layer. The amount of intrusion can be reduced. This ensures the long-term reliability that is the most important feature of EL panels,
It is possible to produce a color EL panel capable of maintaining excellent display quality.

According to the second aspect of the present invention, since the convex portion is formed in a frame shape, the thickness of the adhesive layer can be kept constant.

According to the third aspect of the present invention, since the substrate and the convex portion are integrally formed by etching, the number of bonded portions is one in comparison with the conventional technology in which a separately provided spacer is attached with an adhesive. At the location, whereby it is possible to suppress the permeation of moisture.

According to the present invention, the spacer formed separately is formed on the substrate with frit glass instead of being attached to the substrate with an adhesive. Thereby, permeation of moisture can be suppressed.

According to the present invention, since the thickness of the adhesive layer is selected to be 2 μm or more and 10 μm or less,
The life characteristics of the color EL panel can be improved to the same level as the monochrome EL panel.

According to the sixth aspect of the present invention, the height of the projection is selected to be not less than 10 μm and not more than 50 μm. It is possible to realize a high viewing angle of 160 ° up, down, left, and right without deteriorating the color filter.

According to the present invention, the thin film EL
Since the element has at least one or more insulating layers and at least one or more EL light emitting layers, the thin film EL which emits white light including three primary colors by combining a plurality of light emitting layers is provided.
An element can be formed.

According to the present invention, since the thin-film EL element is an organic EL element, the operating voltage can be reduced, and light emission in a wide area can be achieved in view of the variety of organic materials. Color can be realized.

According to the ninth aspect of the present invention, since the extraction electrode is formed by the mask vapor deposition method, the resist caused by the non-uniform resist coating caused when patterning is performed on the projections by a photo process, for example. It is possible to prevent the occurrence of an uneven portion of the pattern thickness and the disconnection or short circuit of the electrode pattern after the etching, thereby significantly improving the production yield of the EL panel.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a color EL panel 30 according to a first embodiment of the present invention.

FIG. 2 is a plan view of the thin-film EL element 31. FIG.

FIG. 3 is a graph showing a relationship between an adhesive layer thickness t of the color EL panel 30 and a panel life.

FIG. 4 is a sectional view showing a color EL panel 50 according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a color EL panel 60 according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a color EL panel 69 according to a fourth embodiment of the present invention.

FIG. 7 is a plan view of the thin film EL element 82.

FIG. 8 is a sectional view showing a conventional color EL panel 1.

FIG. 9 is a cross-sectional view showing a conventional EL panel 15.

[Explanation of symbols]

 30, 50, 60, 69 Color EL panel 31, 51, 61, 82 Thin film EL element 32, 55, 78 Color filter 34, 54, 79 Translucent substrate 35, 52, 70 Substrate 36, 62, 71 Lower electrode 37 , 72 Lower insulating layer 38, 64, 73 Light emitting layer 39, 74 Upper insulating layer 40, 66, 75 Upper electrode 41, 53, 81 Convex part 44, 76 Adhesive layer 81 Extraction electrode

Claims (9)

[Claims] 1. A lower electrode on a substrate having electrical insulation,
An EL device includes a thin-film EL element on which an EL light-emitting layer and an upper electrode are formed, and a light-transmitting substrate provided with a color filter opposed to the upper electrode.
In a color EL panel that emits light from a light-transmitting substrate through a color filter, a protrusion is formed on at least one of the substrate and the light-transmitting substrate, and a substrate opposed to the protrusion has an adhesive layer. A color EL panel, wherein the panel is adhered to the panel. 2. The color EL panel according to claim 1, wherein said convex portion is formed in a frame shape. 3. The color EL panel according to claim 1, wherein the convex portion integrally forms the one substrate and the convex portion by etching a base material. 4. The color EL panel according to claim 1, wherein the projection is formed of frit glass. 5. The adhesive layer according to claim 1, wherein the thickness of said adhesive layer is selected to be not less than 2 μm and not more than 10 μm.
The color EL panel according to any one of the above. 6. The height of the projection is selected to be not less than 10 μm and not more than 50 μm.
The color EL panel according to any one of the above. 7. The color EL panel according to claim 1, wherein the thin film EL element has at least one or more insulating layers and at least one or more EL light emitting layers. 8. The color EL panel according to claim 1, wherein said EL element is an organic EL element. 9. An extraction electrode formed from inside to outside with respect to the frame-shaped protrusion, and an extraction electrode having an inside end connected to the upper and lower electrodes is formed by a mask evaporation method. The described color EL panel.