JP2005339854A - Sealing method of organic electroluminescent panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing method of an organic EL panel with excellent productivity of the organic EL panel and with a manufacturing process of the organic EL panel simplified. <P>SOLUTION: In an adhesive coating process S1, coating is made in a circular shape on a sealing substrate (a sealing member) 70. In a first overlapping process S2, the sealing substrate 70 is moved toward an element forming substrate 20 so that an adhesive 9 is in a contact state with the element forming substrate 20 as a standard. In a first room pressure adjustment process S3, pressure in a sealing room 101 is decompressed to a first pressure value after the first overlapping process S2. In a second overlapping process S4, the sealing substrate 70 is made to move toward the element forming substrate 20 in order to crush the adhesive 9 after completion of decompression down to the first pressure value. In a second room pressure adjustment process S5, pressure is raised from the first pressure value to a second pressure value in the sealing room 101, at the time of the crushing of the adhesive 9 at the second overlapping process S4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for sealing an organic EL panel including an organic EL element (organic electroluminescence element) in which an organic layer including at least a light emitting layer is sandwiched between a pair of electrodes.

  Conventionally, as an organic EL panel, a transparent electrode (front electrode) serving as an anode made of ITO (indium tin oxide), a hole injection layer, a hole transport layer, a light emitting layer on a translucent substrate made of a glass material. And an organic layer composed of an electron transport layer and a non-transparent back electrode such as aluminum (Al) serving as a cathode are sequentially laminated to form an organic EL element which is a laminate, and a glass material covering the laminate There is known one in which a sealing member made of is disposed on a translucent substrate. Such an organic EL panel is disclosed in Patent Document 1, for example.

In the manufacturing process of such an organic EL panel, there is a sealing process between the translucent substrate and the sealing member. As the sealing step, an uncured adhesive provided in an annular shape having a cut portion is disposed at a joint portion of the light transmitting substrate with the sealing member, and the sealing member is disposed on the light transmitting substrate. And the both members are pressure-bonded, the predetermined adhesive including the cut portion is left, the other continuous adhesive is cured, and then the adhesive including the cut portion is cured, and the cut Some parts are closed by volume expansion, and an increase in internal pressure in the sealing space at the time of sealing can be eliminated to prevent the occurrence of sealing failure. Such an organic EL panel sealing method is disclosed in Patent Document 2.
JP 2001-267066 A JP 2002-25764 A

  However, since the organic EL panel sealing method described above requires two steps of curing the adhesive, there is room for improvement in terms of productivity when mass production is considered. In addition, in such a method for sealing an organic EL panel, it is difficult to manage the amount of the adhesive applied to form the cut portion, resulting in a complicated manufacturing process of the organic EL panel. It has the problem that it ends up.

  The present invention has been made in view of this problem, and provides an organic EL panel sealing method that is excellent in productivity of an organic EL panel and that can simplify the manufacturing process of the organic EL panel. Objective.

  In order to solve the above-mentioned problems, the present invention forms an organic EL element in which an organic layer including at least a light emitting layer is sandwiched between a pair of electrodes, as in the method for sealing an organic EL panel according to claim 1. A sealing method for an organic EL panel in which a sealing member is disposed on an element forming substrate in a state of covering the organic EL element with an adhesive, and the sealing member and the element forming substrate Adhesive application step of applying the adhesive to at least one of the joint portion or the joining portion of the element forming substrate with the sealing member, and the element forming substrate and the sealing member are put into a room where pressure can be reduced. A first overlapping step in which at least one of the element forming substrate or the sealing member is moved to bring the adhesive into contact with the element forming substrate or the sealing member; Overlay Or after the first superposition step, a first indoor pressure adjustment step for reducing the pressure inside the chamber to a first pressure value, and after the pressure reduction to the first pressure value is completed, A second overlapping step of moving at least one of the element forming substrate or the sealing member to be crushed by a predetermined amount; and the pressure in the chamber is reduced when the adhesive is crushed in the second overlapping step. And a second indoor pressure adjustment step of increasing the pressure value from the first atmospheric pressure value to the second atmospheric pressure value.

  The organic EL panel sealing method according to claim 2 is the organic EL panel sealing method according to claim 1, wherein the adhesive is irradiated with ultraviolet rays after the second indoor pressure adjustment step. An adhesive curing step for curing the adhesive is included.

  The organic EL panel sealing method according to claim 3 is the organic EL panel sealing method according to claim 1, wherein the element forming substrate and the sealing member in the second overlapping step are provided. In the first indoor pressure adjustment step, the internal pressure in the storage space for storing the organic EL element constituted by the element forming substrate and the sealing member is atmospheric pressure at the time of pressure bonding The first atmospheric pressure value is set.

  The organic EL panel sealing method according to claim 4 is the organic EL panel sealing method according to claim 1, wherein the adhesive application step is performed with the element forming substrate of the sealing member. The adhesive is annularly arranged by dispensing or printing at a joint portion or a joint portion of the element forming substrate with the sealing member.

  The organic EL panel sealing method according to claim 5 is the organic EL panel sealing method according to claim 1, wherein the adhesive is mixed with a spacer.

  In the present invention, an organic EL element in which an organic layer including at least a light emitting layer is sandwiched by a pair of electrodes is formed on a light-transmitting substrate, and the organic EL element is sealed in a state of covering the organic EL element. About the sealing method of the organic EL panel which arrange | positions a stop board | substrate via an adhesive agent, it is excellent in productivity of an organic EL panel, and the sealing of the organic EL panel which can simplify the manufacturing process of an organic EL panel You can get the method.

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

  The structure of the organic EL panel will be described with reference to FIGS. The organic EL panel 1 includes a glass substrate 2, a transparent electrode 3, an insulating layer 4, an organic layer 5, a back electrode 6, and a sealing plate (sealing member) 7.

  The glass substrate 2 is a translucent substrate having a rectangular shape, and is an element forming substrate for forming an organic EL element.

  The transparent electrode 3 is made of a conductive material such as ITO on the glass substrate 2, and is formed of a sun-shaped display segment portion 3a, a lead portion 3b formed by being drawn from each segment, and a terminal end of the lead portion 3b. The electrode part 3c provided in a part is provided. The electrode portion 3c group is intensively arranged on one side of the glass substrate 2.

  The insulating layer 4 is made of an insulating material such as polyimide, and has a window portion 4a corresponding to the display segment portion 3a and a notch portion 4b corresponding to an electrode portion described later of the back electrode 6, and has a contour of the light emitting region. In order to display the image clearly, a window portion 4a is formed so as to slightly overlap the peripheral edge portion of the display segment portion 3a of the transparent electrode 3, and a lead portion 3b is provided to ensure insulation between the transparent electrode 3 and the back electrode 6. It is arranged so as to cover the top.

  The organic layer 5 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 5 is disposed with a predetermined size so as to correspond to the location of each window 4a in the insulating layer 4.

  The back electrode 6 is made of a non-translucent conductive material such as aluminum and is disposed on the organic layer 5. The back electrode 6 is electrically connected to a lead portion 6a provided on one side of the glass substrate 2 on which each electrode portion 3c in the transparent electrode 3 is formed. In addition, the electrode part 6b is provided in the terminal part of the lead part 6a, and the lead part 6a and the electrode part 6b are formed of the same material as the transparent electrode 3.

  The sealing plate 7 is made of a glass material, and has a recess-shaped storage portion 7a for storing the organic EL element 8 including the transparent electrode 3, the insulating layer 4, the organic layer 5, and the back electrode 6, and is transparent. The electrode portion 3c of the electrode 3 and the electrode portion 6b of the back electrode 6 are configured to be slightly smaller than the glass substrate 2 and are connected to the glass substrate 2 via the ultraviolet curable adhesive 9 so as to be exposed. A joint portion 7b formed so as to surround the entire circumference of 7a is provided. The sealing plate 7 is obtained by an appropriate means of molding, etching, sand blasting, and cutting.

  The ultraviolet curable adhesive 9 includes a spacer made of glass fiber having a viscosity of 126 Pa · S at room temperature, a diameter of about 50 μm, and a height of about 50 μm.

  The organic EL panel 1 is configured by the above-described units.

  Next, a method for sealing the organic EL panel 1 will be described with reference to FIGS.

  First, an organic EL element 8 comprising a transparent electrode (segment display portion 3a) 3, an insulating layer 4, an organic layer 5 and a back electrode 6, and lead portions 3b and 6a and an electrode portion 3c corresponding to the transparent electrode 3 and the back electrode 6. , 6b are prepared as an element forming substrate 20 which is a multi-substrate formed by a plurality of means such as vapor deposition or sputtering. Also, corresponding to each organic EL element 8, a concave-shaped storage part 70 a (7 a) that stores each organic EL element 8, and a joint that surrounds the periphery of each storage part 70 a and is bonded to the element forming substrate 20. A sealing substrate (sealing member) 70 composed of a plurality of sealing plates 7 provided with a portion 70b (7b) is prepared (see FIG. 4A). In addition, the depth of the accommodating part 70a of the sealing substrate 70 is 0.5 mm, for example.

  Then, the ultraviolet curable adhesive 9 is applied to the formation portion of the joining portion 70b of the sealing substrate 70 by a dispensing method or a printing method (FIG. 4A, FIG. 5, adhesive application step S1). The adhesive application step S1 will be described in detail with reference to FIG. FIG. 6 is a plan view showing the sealing substrate 70, in which the storage portions 70a are formed in rows in the vertical and horizontal directions. Joining portions 70b for joining to the element forming substrate 20 via the adhesive 9 are formed on the periphery of the storage portion 70a, and the joint portions 70b between the storage portions 70a are cut as described later. A cutting position for obtaining each organic EL panel 1 is secured by the process, and a wide area 71 is formed.

  The adhesive 9 is disposed on the bonding portion 70b and the wide area 71 of the sealing substrate 70 along the arrangement pattern 72 shown in FIG. The adhesive 9 is annularly arranged over the entire circumference so as to surround each storage portion 70 a, but the wide area portion 71 has a substantially X-shaped arrangement pattern 72. That is, in the bonding process between the element formation substrate 20 and the sealing substrate 70, a predetermined pressure is applied, but the adhesive 9 is directed outward from the intersecting region of the arrangement pattern 72 in the wide area 71. As a result, it is possible to prevent the entry of outside air into the storage portion 70a. In addition, when the adhesive 9 is applied by the dispensing method, the adhesive 9 can be supplied to the joint portion 70b and the wide area portion 71 with a single stroke using a dispenser, thereby improving the productivity of the adhesive application process. it can. In addition, although the dispensing method or the printing method is used for the adhesive application step S1, the dispensing method is desirable in the case of a production line that supports small-scale production of a large number of models, and the printing method is used in a manufacturing line that supports mass production of a small number of models. desirable. In addition, the thickness of the coating film of the adhesive 9 is about 0.2 mm to 0.4 mm.

  Next, the element forming substrate 20 and the sealing substrate 70 are placed in the sealing chamber 101 of the sealing device 100 as shown in FIG. 7, and the element forming substrate 20 and the sealing substrate 70 are connected by the sealing device 100. Overlay (FIG. 4B, FIG. 5, first overlay step S2).

  Here, the sealing device 100 will be described in detail. The sealing device 100 is provided with a sealing chamber 101. The sealing chamber 101 is evacuated by a vacuum pump (not shown) through the exhaust port 102 so that the sealing chamber is in a substantially vacuum state, and then nitrogen having a predetermined oxygen concentration is introduced from the nitrogen inlet 103. For example, a nitrogen atmosphere having an oxygen concentration of 100 ppm or less and a dew point of −70 ° C. or less is secured. In this case, the atmospheric pressure in the sealing chamber 101 is kept at 1.0 atm.

  In the approximate center of the sealing chamber 101, an element forming substrate 20 and a sealing substrate 70 are disposed, and an overlapping mechanism 104 for overlapping both members 20 and 70 is provided. Above the sealing chamber 101, an ultraviolet irradiation device (hereinafter referred to as a UV irradiation device) 105 that irradiates the adhesive 9 with ultraviolet rays (UV) is provided. Further, between the UV irradiation apparatus 105 and the superposition mechanism 104, an ultraviolet cut mask 107 that is disposed through the holder unit 106 and partially blocks the ultraviolet radiation from the UV irradiation apparatus 105 is disposed. A mask placement unit 108 is provided.

  The overlapping mechanism 104 includes a first placement portion 104a for disposing the element formation substrate 20, a second placement portion 104b for disposing the sealing substrate 70, and a second placement portion. An elevating mechanism 104c is provided that allows the actuator 104b to move upward by a driving means such as a cylinder. Therefore, in the first overlaying step S2, the overlaying mechanism 104 uses the element forming substrate 20 as a reference position, moves the sealing substrate 70 to the element forming substrate 20 by the ascending mechanism 104c, and applies the sealing substrate 70 to the sealing substrate 70. With the adhesive 9 in contact with the element forming substrate 20, the raising mechanism 104c is stopped. A cushion member 104d is disposed between the second mounting portion 104b and the sealing substrate 70. By the cushion member 104d, the lifting mechanism 104c is operated upward to form the sealing substrate 70 as an element. The element forming substrate 20 and the sealing substrate 70 are prevented from being damaged when they are superimposed on the substrate 20.

  Next, after the completion of the first superposition step S2 or during the superposition of the sealing substrate 70 and the element formation substrate 20 (hereinafter referred to as the first superposition step), The atmospheric pressure is reduced by the vacuum pump (FIG. 5, first indoor atmospheric pressure adjusting step S3). The sealing chamber 101 is depressurized from the atmospheric pressure value (1.0 atm) before depressurization to the first atmospheric pressure value P1, for example, 0.7 atm. The reduced pressure (0.3 atm) from the first atmospheric pressure value P1 depends on the size of each storage portion 7a of the sealing substrate 70 and the thickness of the adhesive 9 applied to the joint portion 7b including the wide area portion 71. In the internal pressure (internal pressure) change determined based on the volume of the recessed portion for storing the organic EL element 8 to be determined (volume of the storage space for storing the organic EL element 8), that is, at the time of pressure bonding in the second overlapping step described later, It is set in consideration of the pressure increase of the internal pressure in the storage space.

  Next, after the sealing chamber 101 is depressurized to the first atmospheric pressure value, the second mounting portion 104b provided with the sealing substrate 70 is raised by a predetermined amount by the raising mechanism 104c (the moving amount is about several mm). ) To crush the adhesive 9 to bring the element forming substrate 20 and the sealing substrate 70 into close contact (FIG. 4C, FIG. 5, second overlay step S4).

  At the same time as the second superposition step S4, the pressure inside the sealing chamber 101 is increased from the second pressure value to the second pressure value (1.0 atm), which is the pressure before the pressure reduction. Then, nitrogen gas having a predetermined oxygen concentration is introduced from the nitrogen inlet 103 (second indoor pressure adjustment step S5).

  Next, the adhesive 9 disposed between the element forming substrate 20 and the sealing substrate 70 is cured by irradiating ultraviolet rays from the UV irradiation device 105 for a predetermined time (FIG. 5, adhesive curing step S6), and thereafter The overlapping substrate (organic EL panel) stacked by lowering the raising mechanism 104 c in the sealing chamber 101 is taken out from the sealing chamber 101.

  Then, individual organic EL panels 1 are obtained by cutting predetermined portions of the superposed substrate by, for example, a scribing method (FIG. 4D).

  Such a sealing method of the organic EL panel 1 includes an adhesive application step S1 in which the adhesive 9 is applied to the joint portion 70a of the sealing substrate 70 with the element forming substrate 20, and the element forming substrate 20 and the sealing substrate 70. First, it is put into the depressurized sealing chamber 101, and the sealing substrate 70 is moved to the element forming substrate 20 side with respect to the element forming substrate 20, so that the adhesive 9 comes into contact with the element forming substrate 20. The first indoor pressure adjusting step of reducing the pressure inside the sealing chamber 101 to the first pressure value during the first overlapping step S2 or after the first overlapping step S2. S3, a second overlaying step S4 for moving the sealing substrate 70 to the element forming substrate 20 side by a predetermined amount to crush the adhesive 9 after the pressure reduction to the first atmospheric pressure value is completed, and a second overlaying step Press the adhesive 9 in S4 At the time of splashing, UV irradiation is applied to the adhesive 9 after the second indoor pressure adjustment step S5 in which the pressure in the sealing chamber 101 is increased from the first pressure value to the second pressure value, and after the second indoor pressure adjustment step S6. The apparatus 105 includes an adhesive curing step S6 in which the adhesive 9 is cured by irradiating the apparatus 105 with ultraviolet rays.

  Therefore, the sealing method of the organic EL panel 1 considers the internal pressure of the storage space where the pressure rises by pressure bonding before pressing the element forming substrate 20 and the sealing substrate 70 (crushing the adhesive 9), It is characterized in that the pressure in the sealing chamber 101 is reduced in advance, and the pressure in the sealing chamber 101 is increased by the pressure increase in accordance with the pressure bonding timing. Accordingly, when the element forming substrate 20 and the sealing substrate 70 are pressure-bonded, the internal pressure of the storage space for storing the organic EL element 8 and the external pressure outside the storage space (atmosphere in the sealing chamber 101) are made substantially equal. Therefore, since the trouble that the adhesive 9 formed in a ring shape is torn can be prevented, the element forming substrate 20 and the sealing substrate 70 can be well secured. Moreover, since the cut portion is not formed in the adhesive 9 as in the conventional sealing method, the adhesive curing process can be performed in one step, so that not only the productivity can be improved but also the manufacturing process can be improved. Can also be simplified.

  Further, when the element forming substrate 20 and the sealing substrate 70 are pressure-bonded in the second overlaying step S5, the inside of the storage space for storing the organic EL element 9 composed of the element forming substrate 20 and the sealing substrate 70 is used. Since the first atmospheric pressure value in the first indoor atmospheric pressure adjustment step S2 is set so that the internal pressure becomes approximately 1 atm (atmospheric pressure), the sealing plate 7 is stored in the organic EL panel 1 after sealing. It is possible to prevent bending in the space direction or the non-storage space direction (outward direction).

  In addition, the adhesive application step S5 is a small-scale production of a large number of models in the organic EL panel 1 because the bonding portion 70b of the sealing substrate 70 and the element forming substrate 20 is arranged in an annular shape by dispensing or printing. Or it can be adapted to mass production of a small number of models, and the production efficiency can be secured satisfactorily.

  Moreover, since the adhesive 9 uses a material in which spacers are mixed, pressure management for applying pressure in the pressure-bonding process (second superposition process S4) between the element formation substrate 20 and the sealing substrate 70 is performed. It should be easy.

  In each of the above-described embodiments, the segment display type organic EL panel 1 sealing method is used. However, the present invention may also be applied to a dot matrix type organic EL panel sealing method.

  Further, in the embodiment of the present invention, the element forming substrate 20 and the sealing substrate (sealing member) 70, which are multi-taking substrates for obtaining a plurality of organic EL panels, have been described as examples. Needless to say, the present invention may be applied to a method of sealing an element formation substrate and a sealing member for obtaining a single organic EL panel.

  In the embodiment of the present invention, the adhesive 9 is applied to the joint portion 70 b of the sealing substrate 70, and both members are moved by moving the sealing substrate 70 toward the element forming substrate 20 with respect to the element forming substrate 20. 20 and 70, the adhesive 9 is applied to the joining portion of the element forming substrate 20 and the sealing substrate 70, and the element forming substrate 20 is used as the sealing substrate 70 with the sealing substrate 70 as a reference. Bonding may be achieved by moving to the side.

It is a perspective view which shows the organic electroluminescent panel in embodiment of this invention. It is a top view which shows an organic electroluminescent panel same as the above. It is principal part sectional drawing which shows an organic electroluminescent panel same as the above. It is a figure which shows the manufacturing process of an organic electroluminescent panel same as the above. It is a figure which shows the sealing process of an organic electroluminescent panel same as the above. It is a figure which shows the arrangement | positioning pattern of the adhesive agent of an organic electroluminescent panel same as the above. It is a figure which shows the sealing device of an organic EL panel same as the above.

Explanation of symbols

1 Organic EL panel 2 Glass substrate (Element formation substrate)
3 Transparent electrode 4 Insulating layer 5 Organic layer 6 Back electrode 7 Sealing plate (sealing member)
7a storage part 7b joint part 20 element forming substrate 70 sealing substrate (sealing member)
70a Storage part 70b Joining part 100 Sealing device 101 Sealing chamber 102 Discharge port 103 Nitrogen inlet 104 Superposition mechanism

Claims (5)

A sealing member is disposed via an adhesive on an element forming substrate formed by forming an organic EL element in which an organic layer including at least a light emitting layer is sandwiched between a pair of electrodes so as to cover the organic EL element. A method for sealing an organic EL panel,
An adhesive application step of applying the adhesive to at least one of a joint portion of the sealing member with the element forming substrate or a joint portion of the element forming substrate with the sealing member;
The element formation substrate and the sealing member are put into a chamber that can be decompressed, and at least one of the element formation substrate or the sealing member is moved so that the adhesive is applied to the element formation substrate or the sealing member. A first superimposing step for bringing into contact;
A first indoor pressure adjusting step for reducing the pressure inside the room to a first pressure value during the first overlapping step or after the first overlapping step;
A second overlaying step of moving a predetermined amount of at least one of the element forming substrate or the sealing member to crush the adhesive after completion of decompression to the first atmospheric pressure value;
A second indoor pressure adjustment step of increasing the pressure in the room from the first pressure value to the second pressure value when crushing the adhesive in the second superposition step;
A method for sealing an organic EL panel comprising: The organic EL panel sealing method according to claim 1, further comprising an adhesive curing step in which the adhesive is cured by irradiating the adhesive with ultraviolet rays after the second indoor pressure adjustment step. When the element forming substrate and the sealing member are pressure-bonded with each other in the second overlapping step, in a storage space for storing the organic EL element constituted by the element forming substrate and the sealing member. 2. The organic EL panel sealing method according to claim 1, wherein the first atmospheric pressure value in the first indoor atmospheric pressure adjustment step is set so that the internal atmospheric pressure becomes atmospheric pressure. 3. In the adhesive application step, the adhesive is annularly disposed by dispensing or printing at a joint portion of the sealing member with the element forming substrate, or at a joint portion of the element forming substrate with the sealing member. The organic EL panel sealing method according to claim 1, wherein: The organic EL panel sealing method according to claim 1, wherein a spacer is mixed in the adhesive.

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