JP2007053017A - Organic el panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL panel with a long life which emits light in stable conditions without having moisture adhered to its organic layer. <P>SOLUTION: The organic EL panel is provided with an organic EL element 10 which is formed on a glass substrate 1 and in which an organic layer 4 having at least a luminous layer is formed in lamination between a pair of electrodes (a transparent electrode 2 and a back plate 5), a sealing member which is provided on the glass substrate 1 so as to cover airtightly at least the organic layer 4, and a moisture absorption member 8 which is installed on the organic EL element 10 side in an airtight space S formed by the glass substrate 1 and the sealing member and forms a hydrate by reacting chemically with moisture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic EL panel including an organic EL element formed on a substrate and having an organic layer having at least a light-emitting layer formed between a pair of electrodes, and a method for manufacturing the same.

  As an organic EL panel, on a glass substrate (translucent support substrate) made of a glass material, a transparent electrode that becomes an anode by ITO (Indium Tin Oxide), a hole injection layer, a hole transport layer, a light emitting layer And an organic layer composed of an electron transport layer and a non-translucent back electrode such as aluminum (Al) serving as a cathode are sequentially laminated to form an organic EL element as a laminate, and a glass material covering the laminate A recess-shaped sealing member made of is hermetically provided on the glass substrate via an ultraviolet curable adhesive (photo-curable adhesive), and in an airtight space obtained by the glass substrate and the sealing member There is known one provided with a hygroscopic member, for example, disclosed in Patent Document 1.

Further, as an organic EL panel including a moisture absorbing member, the applicant of the present application has proposed a structure in which a moisture absorbing member having viscosity is provided on a surface of the sealing member facing the organic EL element in Patent Document 2. In such an organic EL panel, a cream-like moisture absorbing member made of a mixture of moisture-absorbing powder particles and an inert liquid is formed in a film shape on the surface of the sealing member facing the organic EL element. Is formed on the support substrate through an ultraviolet curable adhesive, and it is possible to prevent the occurrence of dark spots and a short circuit between both electrodes, and to dispose the moisture absorbing member. This simplifies the sealing process including the process and improves productivity.
JP 2001-267066 A JP 2002-198170 A

  Although the organic EL panel provided with the cream-like moisture absorbing member as described above can exhibit a sufficient function as a moisture absorbing action, for example, when used as a vehicle display device such as a speedometer or an engine tachometer, It is housed in the case body of the vehicle display device with an attachment angle, and the environment in which the vehicle display device is used is subject to vibrations caused by running of the vehicle or reaches a high temperature (for example, about 80 ° C.). There is.

  In the organic EL panel used in such an environment, the moisture absorbing member provided in the sealing member has a non-uniform mixed state of the moisture absorbing powder and the inert liquid, and the vehicle display device A phenomenon occurs in which at least a part of the hygroscopic member flows and partially thickens on the lower end side of the inclined organic EL panel with the attachment angle to the bottom (hereinafter referred to as a liquid dripping portion).

  Therefore, particularly when the organic EL panel is thinned, when the clearance between the organic EL element and the moisture absorbing member becomes small, the dripping portion interferes with the organic EL element, and the back electrode is particularly affected by the influence of vibration or the like. This causes damage to the side and causes dark spots, short circuits between the two electrodes, and the like. In this case, the problem of shortening the lifetime of the organic EL panel occurs.

  In addition, in the hermetically sealed airtight space, moisture may enter the organic layer side before touching the moisture absorbing member and generate dark spots, so a moisture absorbing member that reliably absorbs moisture is required. It was.

  Accordingly, an object of the present invention is to provide a long-life organic EL panel that emits light in a stable state without moisture adhering to the organic layer. It is in.

  The organic EL panel according to the present invention includes, as described in claim 1, an organic EL element formed on a substrate and having an organic layer having at least a light-emitting layer formed between a pair of electrodes, and at least the organic layer. Hydrating by chemically reacting with moisture provided on the organic EL element side in a hermetic space formed by the sealing member provided on the substrate so as to hermetically cover and the substrate and the sealing member And a hygroscopic member for forming an object.

  Moreover, as described in claim 2, in the organic EL panel according to claim 1, the moisture absorbing member is formed in a film shape having a film thickness of 5 μm or less.

  In addition, as described in claim 3, in the organic EL panel according to claim 1 or 2, the moisture absorbing member has a dehydration start temperature of 100 ° C. or more.

  In addition, as described in claim 4, in the organic EL panel according to any one of claims 1 to 3, the moisture absorbing member contains strontium bromide.

  Moreover, the manufacturing method of the organic EL panel of the present invention includes, as described in claim 5, an organic EL element in which an organic layer having at least a light emitting layer formed on a substrate is laminated between a pair of electrodes, A sealing member provided on the substrate so as to hermetically cover at least the organic layer, and a moisture and chemicals provided on the organic EL element side in an airtight space formed by the substrate and the sealing member. A method of manufacturing an organic EL panel comprising a moisture absorbing member that reacts to form a hydrate, the organic EL element forming step of forming the organic layer and the electrode on the substrate, and the sealing member And a moisture absorbing member forming step of forming the moisture absorbing member by a vapor deposition method between the organic EL element forming step and the sealing step.

  In addition, as described in claim 6, in the method for manufacturing an organic EL panel according to claim 5, a heating and dehydrating step of heating the moisture absorbing member between the moisture absorbing member forming step and the sealing step. It is characterized by including.

  The present invention relates to an organic EL panel including an organic EL element formed on a substrate and having an organic layer having at least a light-emitting layer laminated between a pair of electrodes, and a method for manufacturing the same. Thus, a long-life organic EL panel that emits light in a stable state can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2, the organic EL panel includes a glass substrate (substrate) 1, a transparent electrode (electrode) 2, an insulating layer 3, an organic layer 4, a back electrode (electrode) 5, a sealing substrate ( It is mainly composed of a sealing member 6, an adhesive member 7 (sealing member), and a hygroscopic member 8.

  The glass substrate 1 is a translucent support substrate having a rectangular shape.

  The transparent electrode 2 is made of a conductive material such as ITO and is provided on the glass substrate 1. The transparent electrode 2 includes a Japanese-shaped display segment portion 2a, lead portions 2b each formed by being drawn out from each segment, and a terminal portion 2c provided at a terminal portion of the lead portion 2b. In this case, the terminal portion 2 c is provided concentrated on one side of the glass substrate 1.

  The insulating layer 3 is made of, for example, an insulating material such as polyimide or phenol, and is formed so as to cover the lead portion 2 b in order to ensure insulation between the transparent electrode 2 and the back electrode 5. The insulating layer 3 has a window portion 3a corresponding to the shape of the display segment portion 2a and a notch portion 3b corresponding to a terminal portion to be described later of the back electrode 5, and clearly displays the outline of the light emitting region. Therefore, the window 3a is formed so as to slightly overlap with the peripheral edge of the display segment 2a of the transparent electrode 2.

  The organic layer 4 is provided on the insulating layer 3 and the transparent electrode 2. The organic layer 4 may have at least a light emitting layer, but in the embodiment of the present invention, a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer are sequentially laminated. is there. The organic layer 4 is provided with a predetermined size so as to correspond to the location where the window 3 a is formed in the insulating layer 3.

  The back electrode 5 is made of a metallic conductive material such as aluminum (Al), aluminum lithium (Al: Li), or magnesium silver (Mg: Ag), and is provided on the organic layer 4. The back electrode 5 is electrically connected to a lead portion 5 a provided on one side of the glass substrate 1 so as to be adjacent to each terminal portion 2 c in the transparent electrode 2. In addition, the terminal part 5b is provided in the terminal part of the lead part 5a, and the lead part 5a and the terminal part 5b are formed of the same material as the transparent electrode 2.

  As described above, the organic EL element 10 formed by sequentially laminating the transparent electrode 2, the insulating layer 3, the organic layer 4, and the back electrode 5 on the glass substrate 1 is obtained. Moreover, the organic layer 4 provided on the glass substrate 1 and the like can be airtightly covered by the sealing member including the sealing substrate 6 and the adhesive member 7.

  As the sealing substrate 6, for example, a flat plate having a smooth surface 6 a made of the same material as that of the glass substrate 1 can be applied. The sealing substrate 6 is configured slightly smaller than the glass substrate 1 so that the terminal portion 2c of the transparent electrode 2 and the terminal portion 5b of the back electrode 5 are exposed to the outside.

  As the adhesive member 7, for example, a fast-curing material made of an ultraviolet curable epoxy resin adhesive can be used. The adhesive member 7 adheres and fixes the sealing substrate 6 on the glass substrate 1 and supports the sealing substrate 6 at a predetermined interval (for example, 0.6 mm) with respect to the glass substrate 1. It is provided as a spacer. The adhesive member 7 is provided in a predetermined frame shape that surrounds at least the organic layer 4, and the glass substrate 1 and the sealing substrate 6 are hermetically bonded at a predetermined interval, thereby sealing the organic layer 4. An airtight space S is formed so that the organic layer 4 does not touch the external atmosphere. The predetermined distance between the glass substrate 1 and the sealing substrate 6 is set to a value that takes into account the shape such as the thickness of the organic EL element 10 so that the sealing substrate 6 does not touch the organic EL element 10 or the hygroscopic member 8. The

  The hygroscopic member 8 is made of a compound that can react with water to form a stable hydrate. For example, strontium bromide can be applied to the moisture absorbing member 8 and is formed on the back electrode 5 of the organic EL element 10 with a film thickness of about 2 μm. Since the moisture absorption member 8 has a dehydration start temperature of 100 ° C. or higher, for example, even in an in-vehicle use, the hydrate can be stably retained. As the moisture absorbing member 8, a member that chemically adsorbs moisture can be applied, and strontium chloride or strontium hydroxide may be used. Further, the hygroscopic member 8 may contain a member (for example, a porous material such as zeolite) that physically adsorbs moisture to a member that chemically adsorbs moisture.

  The organic EL panel is configured by the above-described units.

  Next, a method for manufacturing an organic EL panel will be described with reference to FIG.

  First, in the transparent electrode forming step, a conductive material is formed in layers on the glass substrate 1 by means such as sputtering, and further patterned according to the display design by photolithography or the like to display the display segment portion 2a and the lead portion A transparent electrode 2 having an anode 2b and an electrode portion 2c is formed (step S1). At this time, the lead portion 5 a and the terminal portion 5 b are formed of the same material as that of the transparent electrode 2.

  Next, in the insulating layer forming step, an insulating material is formed in layers by means such as a spin coat method, and is patterned by means such as a photolithography method to emit light from the portions corresponding to the terminal portions 2c and 5b and the display segment 2a. The part corresponding to the region and the part corresponding to the lead part 5a of the back electrode 5 are removed to form the insulating layer 3 having the window part 3a and the notch part 3b (step S2).

  Next, as a pretreatment for providing the organic layer 4 and the back electrode 5, a cleaning process for cleaning the glass substrate 1 provided with the transparent electrode 2 and the insulating layer is performed (step S3). This cleaning step can be performed by a process such as plasma cleaning or UV ozone cleaning. In addition, the glass substrate 1 provided with the transparent electrode 2 and the insulating layer is subjected to a cleaning process, and then is transported to a vapor deposition apparatus in a dried state, and an organic layer forming step is performed.

  In the organic layer forming step, the glass substrate 1 subjected to the cleaning step is vapor-deposited with a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer in a shape that overlaps at least the display segment 2a serving as a light emitting region. Are sequentially stacked by the above means (step S4).

  Next, in the back electrode forming step, a back electrode 5 serving as a cathode is formed by laminating conductive materials in layers by means such as vapor deposition (step S5). The back electrode 5 is connected to a lead portion 5 a provided in advance on one side of the glass substrate 1.

  By the organic EL element formation process which consists of the above process, the organic EL element 10 which consists of a transparent electrode, an organic layer, and a back electrode on the glass substrate 1 is laminated | stacked. In this case, at least the organic layer forming step and the back electrode forming step are processed in a vacuum atmosphere.

  Next, in this vacuum atmosphere, a hygroscopic member forming step of laminating the hygroscopic member 8 on the back electrode 5 by means such as vapor deposition is performed (step S6). In the organic EL element 10, the moisture absorption member 8 can be laminated | stacked on locations other than the location where the adhesive member 7 is apply | coated by the sealing process mentioned later. The amount of the hygroscopic member 8 is set according to the hygroscopic ability of the hygroscopic member 8, the volume of the airtight space S, and the like. In this case, the hygroscopic member 8 is formed with a film thickness of about 2 μm and the same area as the back electrode 5. In this hygroscopic member forming step, the hygroscopic member 8 can be quickly formed in the same atmosphere as the organic layer forming step and the back electrode forming step of the organic EL element forming step, so that the organic layer 4 may come into contact with moisture. Can be reduced.

  Next, a heating and dehydration process is performed in which the moisture absorbing member 8 formed in the organic EL element 10 is heated to separate and dehydrate the hydrate retained by the moisture absorbing member 8 as moisture (step S7). In the heating and dehydrating step, it is necessary to heat at least a temperature lower than the heat-resistant temperature of the organic EL element 10 and higher than the dehydration start temperature of the moisture absorbing member 8. In this case, the hygroscopic member 8 can be dried by heat treatment at a temperature of about 120 ° C. The hygroscopic capacity of the hygroscopic member 8 can be increased by performing a heat dehydration step before performing a sealing step described later.

  Next, an adhesive member application process in which the adhesive member 7 is applied to the sealing substrate 6 so as to be formed in a predetermined frame shape surrounding the organic layer 4, and the sealing substrate 6 to which the adhesive member 7 is applied A sealing process (step S8) including a sealing process in which the glass substrate 1 is hermetically bonded to the glass substrate 1 at a predetermined interval is performed. The adhesive member application treatment can be applied by a dispenser device in a nitrogen atmosphere having a predetermined nitrogen concentration. Further, the sealing process is performed by sandwiching the adhesive member 7 between the glass substrate 1 and the sealing substrate 6 in a nitrogen atmosphere having a predetermined nitrogen concentration, and irradiating the organic EL element 10 with ultraviolet rays in an airtight state. The adhesive member 7 is cured while holding the airtight space S for storage.

  Such an organic EL panel includes an organic EL element 10 formed on a glass substrate 1 and having an organic layer 4 having at least a light emitting layer laminated between a pair of electrodes (a transparent electrode 2 and a back electrode 5), and at least an organic layer. 4 in a hermetic space S formed by the sealing member provided on the glass substrate 1 so as to hermetically cover 4 and the glass substrate 1 and the sealing member. A hygroscopic member 8 that reacts to form a hydrate.

  Therefore, by providing the hygroscopic agent 8 that chemically absorbs moisture on the organic EL element 10 side, moisture that is likely to enter the organic layer 4 can be absorbed at a position close to the organic layer 4. Generation of dark spots caused by touching can be prevented. Further, by using the chemical moisture absorbing member 8, it is possible to provide an organic EL panel having a long life in a stable state without dripping phenomenon.

  Further, since the moisture absorbing member 8 can be formed in a film shape having a film thickness of 5 μm or less by a vapor deposition method, it is possible to prevent the occurrence of dark spots due to contact with the sealing substrate 6.

  Further, the moisture absorbing member 8 is made of a material such as strontium bromide and has a dehydration start temperature of 100 ° C. or higher, so that the moisture absorbing member 8 is in a stable state even in a harsh environment such as being mounted on a vehicle. Thus, an organic EL panel with a long lifetime can be provided.

  Moreover, the manufacturing method of this organic electroluminescent panel is the organic EL element formation process which forms the organic layer 4 and the electrodes 2 and 5 in the glass substrate 1, and the sealing substrate 6 with which the adhesive member 7 was apply | coated on the glass substrate 1. A thin moisture absorbing member 8 is quickly formed by including a sealing step to be provided and a moisture absorbing member forming step of forming the moisture absorbing member 8 by vapor deposition between the organic EL element forming step and the sealing step. be able to.

  In the embodiment of the present invention, the organic EL panel composed of the above-described components has been described as an example. However, the present invention is not limited to this, and the configuration and processing have the same effect. For example, the film thickness and shape of the hygroscopic member according to the volume of the airtight space surrounded by the sealing member and the glass substrate can be appropriately selected. In addition to the moisture absorbing member 8 provided on the organic EL element 10 side, the same material as the moisture absorbing member 8 described above or a material that physically absorbs moisture, such as a porous material, is provided on the sealing substrate 6 side in the airtight space S. It can also be provided.

  Further, as the sealing member, not a flat sealing substrate, but a substrate made of a glass material may be cut to form a recess, or a sealing material may be made of a metal material.

The perspective view which shows the organic electroluminescent panel in embodiment of this invention. The fragmentary sectional view of the organic electroluminescent panel in embodiment same as the above. The figure which shows the manufacturing process of the organic electroluminescent panel in embodiment same as the above.

Explanation of symbols

1 Glass substrate (substrate)
2 Transparent electrode (electrode)
4 Organic layer 5 Back electrode (electrode)
6 Sealing substrate (sealing member)
7 Adhesive member (sealing member)
8 Hygroscopic member 10 Organic EL element

Claims (6)

An organic EL element in which an organic layer having at least a light-emitting layer formed on a substrate is laminated between a pair of electrodes;
A sealing member provided on the substrate so as to hermetically cover at least the organic layer;
A moisture absorbing member that is provided on the organic EL element side in a hermetic space formed by the substrate and the sealing member and that chemically reacts with moisture to form a hydrate. Organic EL panel.   The organic EL panel according to claim 1, wherein the moisture absorbing member is formed in a film shape having a film thickness of 5 μm or less.   The organic EL panel according to claim 1, wherein the moisture absorbing member has a dehydration start temperature of 100 ° C. or higher.   The organic EL panel according to claim 1, wherein the moisture absorbing member contains strontium bromide. An organic EL element in which an organic layer having at least a light emitting layer formed on a substrate is laminated between a pair of electrodes, and a sealing member provided on the substrate so as to airtightly cover at least the organic layer; Manufacture of an organic EL panel comprising: a moisture absorbing member provided on the organic EL element side in a hermetic space formed by the substrate and the sealing member and chemically reacting with moisture to form a hydrate. A method,
An organic EL element forming step of forming the organic layer and the electrode on the substrate;
A sealing step of providing the sealing member on the substrate;
A method of manufacturing an organic EL panel, comprising: a hygroscopic member forming step of forming the hygroscopic member by a vapor deposition method between the organic EL element forming step and the sealing step. The method for producing an organic EL panel according to claim 5, further comprising a heating and dehydrating step of heating the moisture absorbing member between the moisture absorbing member forming step and the sealing step.

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