KR20050021585A - Sealing plate for electroluminescence element and mother glass substrate for taking a large number of sealing plates - Google Patents

Abstract

The present invention provides an EL element encapsulation plate capable of improving durability against external pressure and preventing damage even under external pressure, and a mother glass substrate for multiple encapsulation of the encapsulation plate. ) Each includes a plate-shaped transparent substrate, an organic EL laminate, and a sealing plate. The encapsulation plate has a recess in which the central portion is processed into a concave shape in order to define a peripheral protrusion in the peripheral portion. The chemical strengthening process of the sealing plate 30 which the organic electroluminescent element 100 has is carried out by ion exchange. Moreover, the sealing plate 30a which the organic electroluminescent element 104 has has the curved part 35 of curvature radius 300micrometer in the corner part 34 of the recessed part 32a.

Description

SEALING PLATE FOR ELECTROLUMINESCENCE ELEMENT AND MOTHER GLASS SUBSTRATE FOR TAKING A LARGE NUMBER OF SEALING PLATES}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an encapsulation plate for an electroluminescent element and a mother glass substrate for multifaceting of the encapsulation plate. In particular, the center portion has a concave shape so as to cover the EL laminate stacked on the substrate. It relates to a specified sealing plate for EL elements and a mother glass substrate for the sealing plate multifaceted.

Electroluminescence (hereinafter referred to as "EL") elements are suitably used as display portions of electronic devices such as mobile phones and car navigation systems, and generally include a substrate having an EL laminated film formed on its surface, and a substrate shape. In order to cover the EL laminated film formed in the upper surface, the top surface is composed of an EL element encapsulation plate processed in a concave shape in order to define the peripheral protrusions adhered to the substrate through the adhesive as the peripheral portions. The substrate and the encapsulation plate are adhered through an adhesive layer made of an adhesive applied to the encapsulation portion between the substrate and the peripheral protrusion.

As a material of this sealing plate, metal, glass, resin, or the like is used. In the case where the encapsulation plate is made of metal, it is necessary to mix the insulating spacer with the adhesive applied to the encapsulation portion between the substrate and the peripheral protrusion for the purpose of preserving the electrical insulation of the lead electrode portion formed on the substrate. The gap with the peripheral protrusion becomes larger by the spacer portion, and the possibility of outside moisture invading into this portion increases. In addition, in the top emission structure in which light from the light emitting layer is taken out from the sealing plate side, transparency is required for the sealing plate, and therefore, the sealing plate made of metal cannot be used.

Therefore, when the EL element adopts a top emission structure, the sealing plate is made of plastic or glass having insulation and transparency. However, plastic is rarely used as a material of an encapsulation plate because of its absorbency, while glass is widely used as a material of an encapsulation plate because of its excellent insulation, transparency and water resistance.

As a processing method of the glass sealing plate, there exists a press method which bends and processes a glass platen itself, and the sandblasting method which removes the center part of a glass platen, and there exists an etching method in addition to this. According to this etching method, the flatness of the top surface of the periphery of the periphery is high, and small cracks do not occur on the surface of the central concave portion. Can be done.

In addition, the top-emitting EL element provided with the sealing plate for EL elements produced as mentioned above is used as a display element of information display apparatuses, such as a mobile telephone and an electronic notebook, and is used not only indoors but also outdoors.

However, the display device of the above-mentioned electronic device often receives pressure from the outside, and the sealing plate for EL elements needs to have the ability to counteract the pressure from the outside. On the other hand, glass commonly used as the material of the encapsulation plate is particularly vulnerable to tensile stress, and therefore, there is a first problem that a strength that can be sufficiently tolerated for tensile stress that can be applied even under indoor use is required.

In addition, when an external pressure that is greater than an external pressure applied indoors, such as outdoor use, is subjected to tensile stress on the inner wall of the sealing plate, particularly, at the corners of the sealing plate recess, breakage of the sealing plate is likely to occur. Has a second problem.

A first object of the present invention is to provide an EL element sealing plate capable of improving durability against external pressure and a mother glass substrate for the sealing plate multifaceted.

Moreover, the 2nd objective of this invention is providing the sealing plate for EL elements which can prevent damage, and the mother glass substrate for multifaceting of the sealing plate for EL elements.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the organic electroluminescent element provided with the sealing plate for EL elements which concerns on 1st Embodiment of this invention.

FIG. 2 is a plan view of an encapsulation plate multifaceted mother glass substrate in which an encapsulation plate for an EL element used in the EL element of FIG. 1 is formed in a substantially matrix form.

3 is a cross-sectional view of an organic EL device having the sealing plate for EL devices of Comparative Example 1. FIG.

4 is a cross-sectional view of an EL element having a sealing plate for EL elements according to a second embodiment of the present invention.

It is explanatory drawing of the evaluation method of the presence or absence of damage of the recessed part of the sealing plate for EL elements of an Example and a comparative example.

6 is a cross-sectional view of an EL element including the sealing plate for the EL element of Comparative Example 2. FIG.

(Initiation of invention)

In order to achieve the said 1st objective, the EL element sealing plate which concerns on the 1st aspect of this invention is a glass EL element sealing plate which covers the EL laminated body laminated | stacked on the board | substrate, and a reinforcement process is given to the surface. It is characterized by.

In the sealing plate for EL elements which concerns on a 1st aspect, it is preferable that the said sealing plate consists of alkali containing glass, and the said strengthening process consists of chemical strengthening processes.

Moreover, it is preferable that the said chemical strengthening process is performed by the ion exchange method.

In the sealing plate for EL elements which concerns on a 1st aspect, it is preferable that the said reinforcement process is performed by a wind-cooling strengthening method.

In order to achieve the above-mentioned first object, the mother glass substrate for sealing plate multi-faceted sheet according to the first aspect of the present invention is characterized in that the sealing plate for EL elements is formed in a substantially matrix form.

 In the mother glass substrate which concerns on a 1st aspect, it is preferable that the said reinforcement process is performed after masking between the said sealing plates, and between the said sealing plates is cut | disconnected after the said reinforcement process.

In order to achieve the above-mentioned second object, the EL element sealing plate according to the second aspect of the present invention is an EL element sealing plate whose central portion is defined in a concave shape so as to cover an EL laminate stacked on a substrate. And a curved portion at the corner of the concave portion.

In the EL element sealing plate according to the second aspect, the radius of curvature of the curved portion is preferably 50 µm or more.

In the sealing element for EL elements which concerns on a 2nd aspect, it is preferable that the said recessed part was formed by the etching method.

Moreover, it is preferable that the said etching method is a wet etching method.

In addition, the mother glass substrate for a multi-faceted mother glass substrate for an EL element according to the second aspect is characterized in that the EL element sealing plate is formed in a substantially matrix form.

(The best mode for carrying out the invention)

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to achieve the said 1st objective, this inventor discovered that in the sealing plate for EL elements made of glass which covers the EL laminated body laminated | stacked on the board | substrate, when a surface is strengthened, It was found that the durability of the sealing plate for EL elements can be improved, and sufficient strength can be obtained to withstand practical use.

Further, the present inventor has conducted intensive studies to achieve the second object. As a result, in the sealing plate for EL elements in which the center portion is defined in a concave shape so as to cover the EL laminate stacked on the substrate, the corners of the concave portion are provided. When the part has a curved part, Preferably the curved part whose curvature radius is 50 micrometers or more, it discovered that the damage of the sealing plate for EL elements can be prevented.

In addition, the present inventors conducted intensive studies to achieve the second object. As a result, when the concave portions were formed by the etching method, the inventors found that the radius of curvature of the curved portion can be set to a desired value.

This invention is made | formed according to the said research result.

EMBODIMENT OF THE INVENTION Hereinafter, the sealing element for EL elements which concerns on 1st Embodiment of this invention is demonstrated, referring drawings.

1 is a cross-sectional view of an EL element having a sealing plate for EL elements according to a first embodiment of the present invention.

In Fig. 1, the bottom emission organic EL device 100 has a passive structure, and has a plate-shaped transparent alkali-free glass substrate 10 having a width of 7.0 cm and a thickness of 1.0 mm. And an organic EL laminate 20 formed on the substrate 10 and an encapsulation plate 30 formed to cover the organic EL laminate 20.

The sealing plate 30 is formed of a glass platelet made of a plate-shaped transparent alkali glass (for example, NA-35: made by NH Technograph Co., Ltd.) of 5.0 cm in size and 0.70 mm in thickness by a wet etching method, for example. In order to define the peripheral projections 31 having a width of 2.0 mm at the periphery of the recess 32, the center is processed into a concave shape, and the thickness of the bottom of the recess 32 is 0.4 mm. In addition, the sealing plate 30 is subjected to reinforcement treatment. The board | substrate 10 and the peripheral protrusion part 31 are provided in the sealing part formed between the board | substrate 10 and the top surface of the peripheral protrusion part 31, for example, the contact bonding layer 40 which consists of an adhesive agent of ultraviolet-curable epoxy resins. Glued through).

In the adhesion of the sealing plate 30 to the substrate 10, first, a predetermined amount of adhesive is applied to the peripheral protrusions 31, and then the sealing plate 30 is placed on the substrate 10, and then the sealing plate 30 ) Is irradiated with ultraviolet light while pressing the substrate 10.

Formation of the recessed part 32 in a glass platen first forms the center part of a glass platen in a concave shape by the wet etching method mentioned later, and then chemically strengthens this glass platen by an ion exchange method, for example. This is done by performing the process (indicated by 311 in FIG. 1).

As for the thickness of the recessed part 32 bottom part of the sealing plate 30, 0.3-2.0 mm is preferable. If the thickness is less than 0.3 mm, the strength of the bottom portion of the concave portion 32 of the encapsulation plate 30 is too small. If the thickness is larger than 2.0 mm, the strength of the encapsulation plate 30 can be sufficiently obtained, but the EL element 100 can be thinned. It becomes impossible.

Molecular sheave 50 (manufactured by Union Carbide) is applied to the bottom surface 33 of the recess 32 of the sealing plate 30 to adsorb moisture. In addition, at the time of application of the molecular sieve 50 and the adhesion of the sealing plate 30 to the board | substrate 10, it is preferable to carry out in a dry atmosphere or a reduced pressure state, in order to remove the influence of moisture or oxygen.

Further, in the present embodiment, I use the most suitable molecular sieve 50 as an absorbent, the present invention is not limited thereto, for example, silica gel (SiO _2), decitex kite (desiccite) (clay (clay) based desiccant) , Calcium chloride, calcium oxide, calcium silicate or the like may be used.

The organic EL laminated body 20 is formed on the board | substrate 10, and contains the transparent conductive film 21 which consists of an ITO film of 300 nm in thickness, and the light emitting layer mentioned later, The surface of the said transparent conductive film 21 Formed on the surface of the organic EL laminated film 22 and the organic EL laminated film 22 laminated thereon, and connected to the back electrode 23 made of an Mg-Ag alloy having a thickness of 300 nm, and the back electrode 23. And an extraction electrode 24 made of an ITO film having a thickness of 300 nm.

The organic EL laminated film 22 is sequentially formed from a transparent conductive film 21 side into a hole transport layer having a height of 70 nm made of triphenyldiamine, followed by a quinolinol aluminum complex. A light emitting layer having a height of 70 nm is laminated. In addition, a transparent electron transport layer made of triazole or oxadiazole may be provided between the back electrode 23 and the light emitting layer.

It is preferable that the etching liquid used for the said wet etching method contains 5-50 mass% of hydrofluoric acid suitably at least 1 acid selected from the group of inorganic acids which consist of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. Thereby, etching force can be enlarged. In addition, the strong acid selected from the group of these inorganic acids may be simple or a mixture of two or more types.

Moreover, it is preferable that the said etching liquid contains an appropriate amount of 1 type, 2 or more types of organic acids and bases chosen from the group which consists of carboxylic acids, dicarboxylic acids, amines, and amino acids. Moreover, surfactant may be added suitably to the said etching liquid, and surfactant added may be changed suitably.

The components and the concentration of the etching solution as described above are appropriately changed depending on the temperature of the etching solution and the composition and type of the glass to be etched. In addition, when performing an etching process, it is also effective to rock the etched glass or to give a weak output ultrasonic wave. Thereby, etching liquid can be made into a uniform solution. Moreover, when performing an etching process, it extracts from etching liquid and consists of water or at least 1 acid chosen from the group of inorganic acids which consist of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid once, or it consists of carboxylic acids, dicarboxylic acids, amines, and amino acids. It is also effective to be immersed in one or two or more organic acids or bases selected from the group. Thereby, an etching process can be performed uniformly.

In addition, the sealing plate 30 is processed into a concave shape by a wet etching method or the like, and a reinforcement treatment is performed. Thereby, the sealing plate 30 which has sufficient strength practically is obtained. In the reinforcing treatment, the monovalent ions contained in the glass of the sealing plate 30 are replaced with ions having a larger ion radius than that, and the compressive stress on the surface of the sealing plate 30 is increased to provide the sealing plate 30 itself. A chemical reinforcement method for enhancing the strength or a wind-cooled reinforcement for increasing the strength of the sealing plate 30 itself is used.

The chemical strengthening treatment sufficiently cleans and dries the encapsulation plate 30 subjected to the concave processing by the wet etching method, and thereafter, at least one kind of ions among the monovalent ions contained in the encapsulation plate 30. Ion exchange of monovalent ions in the sealing plate 30 is performed by standing the sealing plate 30 in a nitrate, sulfate, chloride, and molten salt of a mixture of ions having a larger ion radius. Accordingly, the compressive stress on the surface of the sealing plate 30 increases, so that the strength of the sealing plate 30 itself increases.

In addition, the wind-cooling strengthening process fully washes and drys the sealing board 30 in which the concave-shaped process was performed by the wet etching method, heats it to near softening temperature, and then quenchs and cools the surface of the sealing board 30. By increasing the compressive stress, the strength of the sealing plate 30 itself can be increased.

According to this embodiment, since the chemical strengthening process or air-cooling strengthening process is given to the surface, the durability of the sealing plate 30 with respect to external pressure can be improved.

In the said embodiment, although the wet etching method is used as a method of forming the recessed part 32 in a glass platen, a dry etching method may be used and a dry etching method and a wet etching method may be used together. In the wet etching method, a batch process can be performed by selecting the component and etching temperature of an etching liquid, and therefore productivity of the sealing plate 30 can be improved. On the other hand, in the dry etching method, although the etching process can be precise, since the batch process is impossible and the sheet process is performed unavoidably, the productivity of the sealing plate 30 is low.

Moreover, although the sealing plate 30 consists of alkali containing glass, if it is glass containing 5 mass% or more monovalent ions, it can be used as a base material for chemical strengthening. In addition, the sealing plate 30 may consist of alkali free glass, and in the case of the base material which cannot perform the chemical strengthening process by ion exchange in this way, surface reinforcement treatment may be performed by air-cooled strengthening (quenching). Can be.

In the present embodiment, the organic EL laminated film 22 has a passive structure, but may have an active structure. In addition, in this embodiment, although the organic electroluminescent element 100 assumed a back light emission structure, it may take a top light emission structure.

In addition, although the organic EL laminated film 22 used what consists of a positive hole transport layer and a light emitting layer, you may use what consists of a positive hole transport layer, a light emitting layer, and the electron carrying layer which consists of triazole and oxadiazole.

In addition, the EL laminated film may be an inorganic EL laminated film instead of the organic EL laminated film 22. In this case, what consists of an insulating layer, a light emitting layer, and an insulating layer in order from the transparent conductive film side, or what consists of an electron barrier layer, a light emitting layer, and a current limiting layer is used.

The sealing plate 30 used for the EL element 100 of FIG. 1 can be cut out from the mother glass substrate for sealing plate multifaceting of FIG.

FIG. 2 is a plan view of an encapsulation plate multifaceted mother glass substrate in which an encapsulation plate 30 used in the EL element 100 of FIG. 1 is formed in a substantially matrix form.

In FIG. 2, the mother glass substrate 200 for multi-sided sealing plate 30 cm long and 40 cm wide has an encapsulation plate 30 formed in a matrix of 5 × 6.

As a method of forming the sealing plate 30 in a 5 * 6 matrix form on a glass platen, there exists a method of removing the predetermined part of a glass platen in concave shape by the etching method containing a wet etching method. As for the glass platen used, it is suitable to use the thing of thickness 1.1mm or less from the viewpoint of thickness reduction of 0.5 mm or more and EL element 100 on the handling.

In this method, first, in order to form an exposed part in 5 * 6 matrix form on an alkali platen, it masks by the tape-shaped resist of 2.5 mm in width, and this masked glass platen is carried out in the above-mentioned etching liquid, It is immersed for about 180 minutes, and it removes in concave shape leaving the protrusion part 101 in a glass platen, and forms the recessed part 102. FIG. After the glass platen is sufficiently washed with pure water, the resist is peeled off.

Thus, since the predetermined part of the glass platen is removed in a concave shape by the wet etching method, the bottom surface of the concave portion 32 of the sealing plate 30 can be reliably flattened, and the sealing plate against external pressure. The strength of 30 can be increased.

Subsequently, as described above, the sealing plate multi-faceted mother glass substrate 200 on which the recesses 102 are formed in a matrix of 5 × 6 is cut at the portions of the protrusions 101 defining the recesses 102. . Thereby, for example, 30 (5x6) sealing plates 30 used for the EL element 100 of FIG. 2 mentioned later can be acquired.

In the said embodiment, although the wet etching method is used as a method of forming the recessed part 102 in a glass platen, a dry etching method may be used and a dry etching method and a wet etching method may be used together.

The encapsulation plate multi-faceted mother glass substrate 200 has an arrangement of the encapsulation plate 30 in a matrix form, but other arrangements may be used as long as the arrangement is suitable for mass production.

In addition, the width of the resist is not limited to 2.5 mm, and the width of the peripheral protrusions 31 of the obtained sealing plate 30 may be equal to or greater than the thickness of the peripheral protrusions 31, so that the share of the sealing plate 30 is increased. In order to ensure, it may be about 1 cm.

According to the encapsulation plate multi-faceted mother glass substrate 200 of FIG. 2, each encapsulation plate 30 can be obtained by cutting and separating, thereby increasing the strength against external pressure at the time of cutting, thereby increasing the lifespan of the encapsulation plate. It can be provided, and also the productivity of the sealing plate 30 can be improved by not performing a sheet processing.

The sealing plate 30 processed into the concave shape by the etching process can be strengthened after being individually cut from the mother glass substrate 200.

EMBODIMENT OF THE INVENTION Hereinafter, the sealing plate for EL elements which concerns on 2nd Embodiment of this invention is demonstrated, referring drawings.

The EL element according to the present embodiment basically has the same structure as the EL element according to the first embodiment. Therefore, the same code | symbol is attached | subjected to the same structure and description is abbreviate | omitted.

4 is a cross-sectional view of an EL element having a sealing plate for EL elements according to a second embodiment of the present invention.

In Fig. 4, the front emission type organic EL element 104 has a passive structure, and is formed on a substrate 10a of a plate-shaped transparent soda-lime glass having a size of 7.0 cm each side and a thickness of 1.0 mm, and formed on the substrate 10a. It consists of the organic EL laminated body 20 and the sealing plate 30a formed so that this organic EL laminated body 20 may be covered.

The sealing plate 30a is made of a plate-free transparent alkali-free glass of 5.0 cm in size and 0.7 mm in thickness, and has a concave shape in the center to define a peripheral projection 31a having a width of 2.0 mm at the periphery of the concave portion 32a. And the thickness of the bottom part of the recessed part 32a is 0.4 mm. In addition, the encapsulation plate 30a has a curved portion 35 having a radius of curvature of 300 µm at the corner portion 34 of the concave portion 32a. The board | substrate 10a and the peripheral protrusion part 31a are adhere | attached through the adhesive layer 40 arrange | positioned at the sealing part formed between the board | substrate 10a and the top surface of the peripheral protrusion part 31a.

In the adhesion of the sealing plate 30a to the substrate 10a, first, after applying a certain amount of adhesive to the peripheral protrusion 31a, the sealing plate 30a is placed on the substrate 10a, and then the sealing plate ( It performs by irradiating an ultraviolet-ray to an adhesive agent, pressing 30a) to the board | substrate 10a.

Formation of the recessed part 32a to the sealing plate 30a is performed by forming the center part of a glass platen in a concave shape by the method similar to the sealing plate 30 which concerns on 1st Embodiment.

As for the thickness of the bottom part of the recessed part 32a of the sealing plate 30a, 0.3-2.0 mm is preferable. If the thickness is less than 0.3 mm, the strength of the bottom portion of the sealing plate 30a is too small. If the thickness is larger than 2.0 mm, the strength of the sealing plate 30 can be sufficiently obtained, but the EL element 104 cannot be thinned.

In the organic EL laminate 20, a conductive film 21 is formed on a substrate 10, and an organic EL laminated film 22 including a light emitting layer described later is stacked on an upper surface of the conductive film 21, The upper transparent electrode 23 is formed in the upper surface of the organic EL laminated film 22, and the lead-out electrode 24 is connected to the upper transparent electrode 23, and is comprised.

In the organic EL laminated film 22, in order from the conductive film 21 side, the 70 nm-high hole transport layer which consists of triphenyldiamine, and the light emitting layer which is 70 nm in height which consists of a quinolinol aluminum complex are arrange | positioned at this time. It is configured. The transparent electron transport layer made of triazole and oxadiazole may be further provided between the upper transparent electrode 23 and the light emitting layer.

A mixture of 20 wt% hydrofluoric acid and 1 wt% sodium dodecylbenzenesulfonate was used as an etching solution for the etching formation, but not limited thereto, and sulfuric acid, hydrochloric acid, An appropriate amount of at least one acid selected from the group of inorganic acids consisting of nitric acid and phosphoric acid may be contained. In addition, the strong acid selected from the group of an inorganic acid may be single or 2 or more types of mixtures.

Moreover, it is preferable that the said etching liquid contains an appropriate amount of 1 type, 2 or more types of organic acids and bases chosen from the group which consists of carboxylic acids, dicarboxylic acids, amines, and amino acids.

Moreover, surfactant may be added suitably to the said etching liquid, and surfactant added may be changed suitably.

The components and the concentration of the etching solution as described above are appropriately changed depending on the temperature of the etching solution and the composition and type of the glass to be etched. In addition, when performing an etching process, it is also effective to rock the etched glass or to give a weak output ultrasonic wave. Thereby, etching liquid can be made into a uniform solution. Moreover, when performing an etching process, it extracts from etching liquid and consists of water or at least 1 acid chosen from the group of inorganic acids which consist of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid once, or it consists of carboxylic acids, dicarboxylic acids, amines, and amino acids. It is also effective to be immersed in one or two or more organic acids or bases selected from the group. Thereby, an etching process can be performed uniformly.

According to this embodiment, since the curved part 35 of the recessed part 32a has the curved part 35 whose radius of curvature is 300 micrometers, it can prevent that the sealing plate 30a is damaged.

In the said embodiment, although the radius of curvature of the curved part 35 is not limited to 300 micrometers, it is preferable that it is 50 micrometers or more.

In the present embodiment, similarly to the first embodiment, the wet etching method is used as a method of forming the recesses 32a in the glass platelets. The dry etching method may be used, or the dry etching method and the wet etching method may be used together. good. In the wet etching method, batch processing can be performed by selecting the component and etching temperature of an etching liquid, and therefore productivity of the sealing plate 30 can be improved. On the other hand, in the dry etching method, although the etching process can be precise, since the batch process is impossible and the sheet process is performed unavoidably, the productivity of the sealing plate 30 is low. In addition, by using the wet etching method and the dry etching method together, it is possible to combine the isotropic etching of the wet etching method and the anisotropic etching of the dry etching method, thereby easily adjusting the radius of curvature of the curved portion 35 to a desired value. I can adjust it.

In this embodiment, although the alkali free glass was used as the glass plate of the sealing plate 30a, the soda-lime glass which performed the alkali elution prevention process after the low alkali glass or the etching in accordance with the structure of the organic electroluminescent element 100,104, or Quartz glass can be used.

In the present embodiment, the organic EL laminated film 22 has a passive structure, but may have an active structure. In addition, in this embodiment, although the organic electroluminescent element 100 and 104 assumed the top light emitting structure, you may take the back light emitting structure. In addition, instead of the organic EL laminated film 22, the EL laminated film may be an inorganic EL laminated film similarly to the first embodiment. In this case, what consists of an insulating layer, a light emitting layer, and an insulating layer in order from the transparent conductive film side, or what consists of an electron barrier layer, a light emitting layer, and a current limiting layer is used.

The sealing plate 30a used for the EL elements 100 and 104 of FIG. 14 is manufactured by the sheet processing as described above, and similarly to the first embodiment. It can cut out from (200).

FIG. 2 is a plan view of an encapsulation plate multifaceted mother glass substrate in which an encapsulation plate 30 used in the EL element 100 of FIG. 1 is formed in a substantially matrix form.

In FIG. 2, the mother glass substrate 200 for multi-sided sealing plates having a length of 30 cm and a width of 40 cm has a sealing plate 30 formed in a matrix of 5 × 6.

As a method of forming the sealing plate 30 in a 5 * 6 matrix form on a glass platen, there exists a method of removing the predetermined part of a glass platen in concave shape by the etching method containing a wet etching method. As for the glass platen used, it is suitable to use the thing of thickness 1.1mm or less from the viewpoint of thickness reduction of 0.5 mm or more and EL element 100 on the handling.

In this method, first, in order to form an exposed part in 5 * 6 matrix form on a glass platen, it masks by the tape-shaped resist of 2.5 mm in width, and this masked glass platen is 10 in the above-mentioned etching liquid. It is immersed for about 180 minutes, and it removes in concave shape leaving the protrusion part 101 in a glass platen, and forms the recessed part 102. FIG. After the glass platen is sufficiently washed with pure water, the resist is peeled off.

Thus, since the predetermined part of the glass platen is removed in a concave shape by the wet etching method, the bottom surface of the concave portion 32 of the sealing plate 30 can be reliably flattened, and the sealing plate against external pressure. The strength of 30 can be increased.

Subsequently, as described above, the sealing plate multi-faceted mother glass substrate 200 on which the recesses 102 are formed in a matrix of 5 × 6 is cut at the portions of the protrusions 101 defining the recesses 102. . Thereby, 30 (5x6) sealing plates 30 can be acquired.

The encapsulation plate multi-faceted mother glass substrate 200 has an arrangement of the encapsulation plate 30 in a matrix form, but other arrangements may be used as long as the arrangement is suitable for mass production.

In addition, the width of the resist is not limited to 2.5 mm, and the width of the peripheral protrusions 31 of the obtained sealing plate 30 may be equal to or greater than the thickness of the peripheral protrusions 31, so that the share of the sealing plate 30 is increased. In order to ensure, it may be about 1 cm.

Moreover, it is preferable that the shape after cut | disconnecting the sealing plate multifaceted mother glass substrate 200 is the same shape as the said sealing plate 30a.

According to the encapsulation plate multi-faceted mother glass substrate 200 of FIG. 2, each encapsulation plate 30 can be obtained by cutting and separating, thereby increasing the strength against external pressure during cutting, and not performing sheet processing. As a result, productivity of the encapsulation plate 30 can be improved.

EMBODIMENT OF THE INVENTION Hereinafter, the Example which concerns on the 1st Embodiment of this invention is described.

MEANS TO SOLVE THE PROBLEM This inventor makes the test piece of the sealing plate which the chemical strengthening process was performed by ion exchange after the center part was processed in the concave shape by the wet etching method in order to define the peripheral protrusion part in the periphery as Example 1, and said chemical What did not perform reinforcement process is made into the comparative example 1 (sealing plate 301 of the organic electroluminescent element 103 of FIG. 3). 3, the same code | symbol is attached | subjected to the component same as the organic electroluminescent element 100 which concerns on 1st Embodiment.

To the test piece of the sealing plate, first, an etching solution composed of a mixture of 20% by mass hydrofluoric acid and 1% by mass sodium dodecylbenzenesulfonate was prepared, and the outer surface, the peripheral surface, and the peripheral protrusions of the glass platelets of Example 1 and Comparative Example 1 were prepared. The masking treatment was performed with an acid resistant tape covering the film, and these test pieces were immersed in the etching solution maintained at 25 ° C. for 60 minutes, and then taken out in the etching solution, thoroughly washed with pure water, and then peeled off the acid resistant tape to obtain a depth of 300 μm. The recessed part and the peripheral protrusion part of width 2.0mm were formed.

Subsequently, after being immersed in the liquid of 20 mass% of HF and 1 mass% of surfactant for 1 hour in the glass plate which consists of soda-lime glass of 5.0 cm of each side and 1.1 mm in thickness, after fully rinsing and drying, After immersing in 420 degreeC potassium nitrate for 8 hours again, the chemical strengthening process which wash | cleans enough was set as Example 1. In addition, the thing which did not perform the chemical strengthening process was made into the comparative example 1.

Subsequently, an appropriate amount of an ultraviolet curable epoxy resin adhesive is applied to the peripheral protrusions of the test pieces of the sealing plates of Example 1 and Comparative Example 1, respectively, and the substrate and the peripheral protrusions on both sides of the substrate and the test piece of the sealing plate. By irradiating the adhesive with ultraviolet rays while applying a force of about 980 N / m 2 (100 kg / m 2) to the encapsulation portion formed between the layers, an adhesive layer was formed on the encapsulation portion between the substrate and the peripheral protrusion, thereby producing an organic EL device. did.

About the surfaces of the glass platelets of Example 1 and Comparative Example 1 obtained in the above process, the respective bending strengths were measured and compared by JIS R-1604.

In Example 1, the bending strength was 392 N / mm 2 (40 kg / mm 2), which was sufficient to withstand external stress under normal use environment of the display portion of the electronic device. As a result, it was found that an EL device with a sealing plate having sufficient breaking strength was obtained.

In Comparative Example 1, the bending strength was as small as 49 N / mm 2 (5 kg / mm 2), and it was found that there was no problem under the normal use environment of the display portion of the electronic device, but it was found that reliability against external stress was insufficient.

According to this embodiment, in the sealing plate for EL elements made of glass covering the EL laminate laminated on the substrate, the surface is strengthened, so that the durability of the sealing plate for EL elements against external pressure can be improved. I knew that.

Hereinafter, the Example concerning 2nd Embodiment of this invention is described.

MEANS TO SOLVE THE PROBLEM In order to define a center part in concave shape by a wet etching method (Examples 2-4, a comparative example 3) or a sandblasting method (comparative example 2), the present inventors put in the periphery of the center recess part in the glass platen made from alkali-free glass. The test piece of the sealing plate 30 in which the peripheral protrusion part was formed was prepared.

Specifically, an etching solution composed of a mixture of 20% by mass hydrofluoric acid and 1% by mass sodium dodecylbenzenesulfonate is prepared, and the masking treatment is performed with an acid resistant tape covering the outer surface, the peripheral surface, and the peripheral protrusion of the glass platen made of alkali-free glass. The test piece was immersed in the etching solution maintained at 25 ° C. for 60 minutes, and then taken out in the etching solution, thoroughly washed with pure water, and then peeled off the acid resistant tape, so that the corner portion 34 had a radius of curvature of 300 µm (implementation). Example 2), a recess having a depth of 0.3 mm having a curved portion of 100 μm (Example 3), 50 μm (Example 4), 30 μm (Comparative Example 3), and a peripheral protrusion having a width of 2.0 mm on the glass platen. It formed and the test piece of the sealing plate was obtained.

Incidentally, in Examples 3, 4 and Comparative Example 3, isotropic etching is performed until the radius of curvature of the corner portions is 100 µm (Example 3), 50 µm (Example 4), 30 µm (Comparative Example 3), respectively. The wet etching method used was used, and the dry etching method capable of anisotropic etching was used for the depth adjustment of the recesses thereafter. Dry etching method as is used a reactive ion etching method for performing etching process from the gas CHF _3.

As shown in Fig. 6, the test piece of the sealing plate produced by the sandblasting method (Comparative Example 2: The sealing plate 30b of the organic EL element 105) has the bottom of the concave portion 32a. Many small cracks 36 peculiar to the sandblasting method are generated on the surface. 6, the same code | symbol is attached | subjected to the component same as the organic electroluminescent element 104 which concerns on 2nd Embodiment.

Subsequently, an appropriate amount of an ultraviolet curable epoxy resin adhesive is applied to the peripheral protrusions of the test pieces of the sealing plates of Examples 2 to 4 and Comparative Examples 2 and 3, respectively, and the substrate and the peripheral parts of the substrate and the sealing plate on both sides of the test pieces. By applying ultraviolet light to the adhesive while applying a force of about 980 N / m 2 (100 kg / m 2) to the encapsulation portion formed between the protruding portions, an adhesive layer is formed on the encapsulating portion between the substrate and the peripheral protruding portion, thereby producing an organic EL element. did.

The external pressure of 24.5 N / cm 2 (2.5 kg / cm 2) or 49 N / cm 2 (5 kg / cm 2) was applied to the organic EL device thus produced in any one of four edge corners of the sealing plate in the horizontal and vertical directions. 15 mm point, for example, added to the range of a circle having a diameter of about 10 mm around the point B (Fig. 5) of 15 mm in the transverse and longitudinal direction from the edge corner A (Fig. 5). In this case, the presence or absence of damage to the recessed portions of the sealing plate was examined. The results are shown in Table 1.

TABLE 1

 Radius of curvature (μm)       Failure observation result  Manufacturing method    External stress 24.5N / ㎠   External stress 49N / ㎠ Example 2   300     Breakage    Breakage  Wet etching Example 3   100      Breakage    Breakage  Wet etching method + dry etching method Example 4    50      Breakage    Breakage  Wet etching method + dry etching method Comparative Example 2    -      damage     damage Sandblast Comparative Example 3    30     Breakage     damage Wet etching method + dry etching method

In Table 1, when the sealing plate has a curved part in the corner part of a recessed part, it turned out that breakage of a sealing plate can be prevented.

Moreover, it turned out that the damage of a sealing plate can be prevented reliably if the curvature radius of a curved part is 50 micrometers or more.

Moreover, when the recessed part was formed by the etching method, it turned out that the curvature radius of a curved part can be made into a desired value.

As explained above in detail, according to the sealing element for EL elements which concerns on the 1st aspect of this invention, in the sealing element for EL elements made of glass which covers the EL laminated body laminated | stacked on the board | substrate, when a surface is strengthened, The durability of the sealing plate for EL elements to external pressure can be improved.

In addition, as explained in detail above, according to the sealing plate which concerns on the 2nd aspect of this invention, since it has a curved part in the corner part of a recessed part, the damage of the sealing plate for EL elements can be prevented.

According to the sealing plate which concerns on a 2nd aspect, since the curvature radius of a curved part is 50 micrometers or more, the effect of the said sealing plate can be exhibited more reliably.

According to the sealing plate which concerns on a 2nd aspect, since the recessed part is formed by the etching method, the curvature radius of a curved part can be made into a desired value.

According to the encapsulation plate multifaceted mother glass substrate for EL elements according to the second aspect, since the encapsulation plate is formed in a substantially matrix form, each encapsulation plate can be obtained by cutting separation, and the external pressure at the time of cutting. The strength can be increased to provide a sealing plate with a long life, and the productivity of the sealing plate can be improved by not performing a sheet treatment.

Claims (11)

The sealing plate for EL elements made of glass which covers the EL laminated body laminated | stacked on the board | substrate WHEREIN: The sealing plate for EL elements characterized by the surface reinforced. The sealing plate for an EL element according to claim 1, wherein the sealing plate is made of an alkali containing glass, and the strengthening treatment is made of a chemical strengthening treatment. The sealing element for an EL device according to claim 2, wherein the chemical strengthening treatment is performed by an ion exchange method. The sealing plate for EL elements according to claim 1, wherein the reinforcement treatment is performed by a wind-cooling reinforcement method. The sealing plate for EL elements of Claim 1 was formed in substantially matrix form, The mother glass board | substrate for sealing plate multiple surface chamfering characterized by the above-mentioned. The mother glass substrate according to claim 5, wherein the reinforcing treatment is performed after masking the sealing plates, and the space between the sealing plates is cut after the reinforcing treatment. An EL element sealing plate whose center portion is defined in a concave shape so as to cover an EL laminate stacked on a substrate, wherein the sealing portion for EL element has a curved portion at the corner portion of the concave portion. 8. The sealing element for an EL element according to claim 7, wherein a radius of curvature of the curved portion is 50 µm or more. 8. The sealing plate for EL device according to claim 7, wherein the recess is formed by an etching method. 10. The sealing plate for EL device according to claim 9, wherein the etching method is a wet etching method. The sealing plate for EL elements of Claim 7 was formed in substantially matrix form, The mother glass board | substrate for EL element sealing plate multifaceted etching characterized by the above-mentioned.