JP4651429B2 - Method for sealing organic electroluminescence element - Google Patents

Description

  The present invention relates to a method for sealing an electroluminescent element that can produce an electroluminescent element with good display quality.

  In recent years, organic electroluminescence (hereinafter abbreviated as organic EL) elements have attracted attention as self-luminous light emitting elements, and development of organic EL displays using these organic EL elements has been promoted. Since organic EL elements have features such as fast response speed, low voltage, and low power consumption driving suitable for moving picture display, organic EL displays include the next generation mobile phones and personal digital assistants (PDAs). It is expected as a display for the next generation.

  The organic EL display includes an organic EL panel having a plurality of organic EL elements for image display, a drive circuit, a drive power supply, and the like.

  When the organic EL element comes into contact with moisture, the light emission characteristics deteriorate. Therefore, it is necessary to seal the organic EL element so as not to come into contact with moisture to form an organic EL panel. For this reason, an organic EL panel is manufactured by bonding together an organic EL substrate on which an organic EL element is formed and a sealing substrate for sealing using a sealing adhesive.

  As a method for sealing an EL element, there is conventionally known a method for sealing an EL substrate and a sealing substrate with a liquid curable resin dropped so as to protrude convexly on the substrate (Patent Document 1). ). However, in this prior art, as shown in the plan view of FIG. 2, the liquid curable resin 22 spreads in a circular shape on the EL substrate 21 (FIG. 2A), and the liquid curable resin 22 is concentric when bonded. Therefore, the voids 23 are formed between the resins 22, and bubbles caused by the voids are generated (FIG. 2B).

When bubbles are generated in the adhesive layer between the organic EL substrate and the sealing substrate, since the refractive index of the bubble portion is different from the refractive index of the surrounding adhesive layer, the color of the bubble portion is visually recognized different from the surrounding color. For this reason, when the organic EL display is displayed, the bubble shape is recognized by human eyes, and there is a problem that the display quality is lowered. Furthermore, since moisture contained in the bubbles penetrates into the organic EL element and degrades the light emission characteristics, the reliability of the organic EL element is lowered. Therefore, in order to provide an organic EL display having good display quality and good reliability, it is necessary to seal the organic EL element without generating bubbles between the organic EL substrate and the sealing substrate. is there.
JP 2000-10506 A

  An object of the present invention is to provide an organic EL display with good display quality and improved reliability by providing a method for sealing an organic EL element that can suppress the generation of bubbles.

  The present invention relates to a method for sealing an organic electroluminescent element, comprising: a first substrate on which an organic electroluminescent element is formed; and a second substrate for sealing the organic electroluminescent element. A step of applying an adhesive in a shape having a linear portion and a protruding portion protruding in a direction intersecting the linear portion on the surface; and pressing the first substrate and the second substrate to cause the adhesive to Expanding the space between the first substrate and the second substrate, and sealing the organic electroluminescence element.

  In the organic electroluminescent element sealing method of the present invention, the adhesive is applied in a shape having a straight part and a protruding part protruding in a direction intersecting with the linear part, thereby using the protruding part as a guide. Since the adhesive can be spread so as to extrude the void, the generation of bubbles can be suppressed. Therefore, at the time of sealing the organic electroluminescence element, generation of bubbles due to the gap can be reduced, and an organic electroluminescence display with good display quality can be provided.

  In the present invention, preferably, the step of applying the adhesive includes a step of linearly applying the adhesive to the surface of one of the first substrate and the second substrate, and the step of applying the linearly. Applying an adhesive in a direction crossing the application direction of the adhesive.

  By using such a sealing method, the cross-sectional shape of the portion where the adhesive intersects becomes a convex shape, and the peripheral adhesive surface sequentially contacts the substrate after the convex portion first contacts the substrate. Since they are in contact with each other, the generation of bubbles due to waviness on the surface of the adhesive can be suppressed, and an organic electroluminescence display with better display quality can be provided.

  Another aspect of the present invention is a method for sealing an organic electroluminescence element, the first substrate on which the organic electroluminescence element and the terminal portion are formed, and the second substrate for sealing the organic electroluminescence element A step of applying a first adhesive at a position corresponding to a position between the organic electroluminescence element and the terminal portion on the surface of one of the substrates; a position corresponding to the organic electroluminescence element; And a step of applying a second adhesive having a viscosity lower than that of the first adhesive to a shape having a protruding portion that protrudes in a direction intersecting the linear portion, and pressing the first substrate and the second substrate Expanding the first adhesive and the second adhesive between the first substrate and the second substrate to seal the organic electroluminescence element , Characterized by having a.

  By using this sealing method, the second adhesive is applied to the terminal portion provided in the vicinity of the organic electroluminescence element by the first adhesive applied at a position corresponding to the space between the organic electroluminescence element and the terminal portion. It is possible to prevent the adhesive from contacting. That is, in the step of spreading the first adhesive and the second adhesive between the first substrate and the second substrate by pressing the first substrate and the second substrate, the first adhesive Has a higher viscosity and a smaller spread than the second adhesive, and therefore the first adhesive does not contact the terminal portion.

  In addition, the second adhesive has a lower viscosity than the first adhesive, and thus easily spreads. However, since the first adhesive has a higher viscosity than the second adhesive, the second adhesive is the first adhesive. The contact with the terminal portion beyond the agent can be prevented, and the second adhesive can be spread along the first adhesive.

  Further, the second adhesive is applied in a shape having a straight portion and a protruding portion that protrudes in a direction intersecting the straight portion, so that the protruding portion serves as a guide and the adhesive is pushed out to the four corners. Since it can be expanded, generation | occurrence | production of a bubble can be suppressed. At the time of sealing the organic electroluminescence element, generation of bubbles due to the gap can be reduced, and an organic electroluminescence display with good display quality can be provided.

  In another aspect of the present invention, preferably, in the step of applying the second adhesive, the second adhesive having a viscosity lower than that of the first adhesive is provided at a position corresponding to the organic electroluminescence element. A step of applying the agent in a straight line, and a step of applying the second adhesive in a direction crossing the application direction of the second adhesive to be applied in a straight line.

  By adopting such a sealing method, the cross-sectional shape of the portion where the second adhesive intersects becomes a convex portion, and after this convex portion first contacts the substrate, the surrounding adhesive surface sequentially contacts the substrate. Therefore, it is possible to prevent bubbles caused by the undulation of the adhesive surface.

  In another aspect of the present invention, preferably, the ratio of the viscosity of the first adhesive to the viscosity of the second adhesive is 24 or more.

  By using such a first adhesive and a second adhesive, the first substrate and the second substrate are pressed against each other by pressing the first substrate and the second substrate. In the step of spreading between the first adhesive and the second substrate, the second adhesive can be more reliably spread along the first adhesive, so that generation of bubbles can be prevented. Further, the second adhesive can be prevented from contacting the terminal portion beyond the first adhesive, and when the second adhesive spreads between the first substrate and the second substrate, It is possible to suppress the first adhesive from adhering to the terminal portion by being pushed by the second adhesive and deforming the first adhesive toward the terminal portion.

  In the present invention, the step of sealing the organic electroluminescence element by pressing the first substrate and the second substrate may be performed under atmospheric pressure. Also in this case, according to the sealing method of the present invention, since the adhesive can be expanded so as to push out the voids at the four corners, the generation of bubbles can be suppressed. Therefore, at the time of sealing the organic electroluminescence element, generation of bubbles due to the gap can be reduced, and an organic electroluminescence display with good display quality can be provided.

  Another embodiment of the present invention is an electroluminescence panel manufactured by any one of the methods described above.

  According to the present invention, an organic EL display having a good display quality can be obtained by filling an organic EL element by filling a liquid curable resin without generating bubbles between the organic EL substrate and the sealing substrate. Technology that can be manufactured can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
First, the structure of an organic EL panel manufactured using the sealing method according to the present embodiment will be described with reference to a schematic cross-sectional view shown in FIG.

1-1. Overall Configuration of Organic EL Panel FIG. 1 is a schematic cross-sectional view for explaining the configuration of an organic EL panel manufactured using the sealing method according to the present embodiment.

  Referring to FIG. 1, an organic EL panel 1 is configured by adhering an organic EL substrate 3 and a sealing substrate 4 with a sealing adhesive 5.

  The organic EL substrate 3 is configured by arranging a plurality of organic EL elements 2 on a TFT substrate 6 on which driving TFTs are arranged.

  The sealing substrate 4 is made of a translucent material having red (R), green (G), and blue (B) color filters 12R, 12G, and 12B on the surface facing the organic EL element 2. ing. Further, a black matrix 13 is disposed between adjacent color filters.

  In this embodiment, the plurality of organic EL elements 2, 2... Are configured to emit white light, and the white light emitted from each of the organic EL elements 2, 2. , G and B color filters 12R, 12G and 12B are taken out to the outside. As described above, in the present embodiment, the top emission configuration is adopted in which the light emission of the organic EL elements 2, 2... Is extracted from the sealing substrate 4 side.

  As shown in FIG. 1, the organic EL elements 2, 2,... Are configured by laminating an anode 7, an organic layer 8, and a cathode 9 in this order from the TFT substrate 6 side. Adjacent organic EL elements 2 and 2 are separated by a cell separation film 10 made of an insulating material.

  The anode 7 is made of, for example, a metal compound such as ITO (indium-tin oxide), and a light reflective material made of a metal or alloy such as Ag (silver) is disposed under the metal compound. Also good. The anode 7 is formed separately for each organic EL element 2, 2,.

  The cathode 9 is made of a light transmissive material made of, for example, a metal compound such as ITO, a metal, or an alloy. In this embodiment, as shown in FIG. 1, the cathode 9 is continuously formed so as to cover the organic EL elements 2, 2. It is said that.

  The cathode 9 is covered with a protective film 11 made of an inorganic material such as SiN (silicon nitride).

  The organic layer 8 has, for example, a structure of (anode) / hole transport layer / light emitting layer / electron transport layer / (cathode) in which a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order from the anode 7 side. Have. However, the structure of the organic layer is not limited to this, and (anode) / light emitting layer / (cathode), (anode) / hole injection layer / light emitting layer / (cathode), (anode) / light emitting layer / electron injection layer / ( Cathode), (anode) / hole injection layer / light emitting layer / electron injection layer / (cathode), (anode) / hole injection layer / hole transport layer / light emitting layer / electron injection layer / (cathode), (anode) / hole A structure such as injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / (cathode) can be employed.

  In the present embodiment, the light-emitting layer is a light-emitting layer having a two-layer structure in which, for example, a light-emitting layer that emits blue light and a light-emitting layer that emits orange light are stacked. It is set as the structure which can light-emit.

  Further, in the present embodiment, the white light emitted from the light emitting layer is extracted to the outside through a color filter to obtain light of three colors of red, green, and blue. A configuration in which light of three colors of red, green, and blue is obtained by separately coating three types of red light emitting layer that emits red, green, and blue light, a green light emitting layer, and a blue light emitting layer.

  Furthermore, in the figure, the adhesive 5 is made of an ultraviolet curable resin, a visible light curable resin, a thermosetting resin, a composite curable resin using ultraviolet light and heat, or a post-curing resin using ultraviolet light. However, when the sealing substrate 4 having a color filter or CCM (color conversion layer) is used, since ultraviolet light cannot pass through the filter portion, a thermosetting resin, a visible light curable resin, a post-curing resin using ultraviolet light, etc. Is used.

  Specifically, the adhesive 5 includes thermosetting resins such as urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, unsaturated polyester resin, polyurethane resin, and acrylic resin. And vinyl acetate resin, ethylene vinyl acetate copolymer resin, acrylic resin, cyanoacrylate resin, polyvinyl alcohol resin, polyamide resin, polyolefin resin, thermoplastic polyurethane resin, saturated polyester resin, cellulose Radical-based photo-curing adhesives using resins such as thermoplastic resins such as polyesters, various acrylates such as ester acrylates, urethane acrylates, epoxy acrylates, melamine acrylates, acrylic resin acrylates, urethane polyesters, Cationic photo-curing adhesives, thiol / ene addition resin adhesives, chloroprene rubber, nitrile rubber, sterene / butadiene rubber, natural rubber, butyl rubber, silicone, etc. , Vinyl-phenolic, chloroprene-phenolic, nitrile-phenolic, nylon-phenolic, epoxy-phenolic, nitrile-phenolic composite polymer adhesives and the like.

1-2. Features of the Present Embodiment A method for manufacturing the organic EL panel shown in FIG. 1 using the sealing method according to the present embodiment will be described below.

  FIG. 3A is a schematic top view of a sealing substrate 4 (an example of a second substrate in the present invention) 4 before bonding. FIG. 3B is a schematic top view of an organic EL substrate (an example of a first substrate in the present invention) 3 provided with a pixel unit 31 including an organic EL element. The first substrate 3 and the second substrate 4 correspond to the organic EL substrate 3 and the sealing substrate 4 in FIG. 1, respectively.

  In the present embodiment, the adhesive 5 is applied in a shape having a straight portion 5a and a protruding portion 5b protruding in a direction intersecting the straight portion near the center of the surface of the second substrate 4. The intersection of the straight line portion 5a and the protruding portion 5b is preferably set near the center of the surface of the second substrate 4. The longitudinal width of the adhesive 5 is set so that the pixel portion 31 is completely covered in a sealed state.

  Next, the 2nd board | substrate 4 and the 1st board | substrate 3 are bonded together by making the surface where the adhesive agent 5 was apply | coated inside. 4 to 7 are schematic diagrams for explaining how the adhesive 5 spreads between the first substrate 3 and the second substrate 4 when the first substrate 3 and the second substrate 4 are pressed. It is a top view.

  When the first substrate 3 and the second substrate 4 are bonded together, the adhesive 5 spreads in the longitudinal direction of the straight portion 5a (the direction of the arrow M) and the protruding direction of the protruding portion 5b (the direction of the arrow L) (see FIG. 4). In the direction of arrow L, the protruding portion 5b acts as a guide, the adhesive 5 spreads in the protruding direction from the portion where the protruding portion 5b is formed, and the two sides of the first substrate 3 and the second substrate 4 facing each other. The central portions 41a and 41a of 41 and 41 are first reached. For this reason, voids remain at the four corners of the pair of substrates 3 and 4 at this stage (FIG. 5).

  When the pressing with the pair of substrates 3 and 4 is further continued, the adhesive 5 further spreads in the direction of the arrow L and the direction of the arrow M on the first substrate 3 and the second substrate 4. Thereafter, as shown in FIG. 6, the adhesive 5 spreads so as to leave the four corners of the first substrate 3 and the second substrate 4. That is, the gaps 17 are pushed out at the four corners.

  Further, when the first substrate 3 and the second substrate 4 are pressed, the adhesive 5 spreads to the four corners of the first substrate 3 and the second substrate 4 as shown in FIG. The first substrate 3 and the second substrate 4 can be bonded without generating bubbles between the second substrate 4 and the second substrate 4. That is, according to the present embodiment, the adhesive 5 spreads in the four corner directions from the center of the first substrate 3 and the second substrate 4, so that the air is interposed between the first substrate 3 and the second substrate 4. Therefore, the first substrate 3 and the second substrate 4 can be bonded to each other without generating bubbles due to the void. Therefore, an organic EL display with good display quality and improved reliability can be manufactured.

  The step of applying the adhesive 5, the step of bonding the first substrate 3 and the second substrate 4, and the step of spreading the adhesive 5 by pressing the pair of substrates 3 and 4 are under reduced pressure or atmospheric pressure, respectively. It doesn't matter if it is done either.

  In addition, the protrusion part 5b of the adhesive agent 5 should just be apply | coated to the shape which has a protrusion part in the direction which cross | intersects the linear part 5a of the adhesive agent 5, and the shape of the protrusion part is not limited. For example, a semicircular shape, a wedge shape, a linear shape, or the like can be applied.

  In the above embodiment, the adhesive 5 is applied to the surface of the second substrate 4, but may be applied to the surface of the first substrate 3.

  The adhesive 5 may be applied by patterning to the above shape using a mask, may be applied by patterning by screen printing, or may be applied by a dispenser.

  In addition, as a method of applying the adhesive 5, a shape having protrusions at both ends, for example, a protrusion 5b is applied in a straight line, and then a straight line 5a is applied in a direction intersecting the protrusion 5b. May be. FIG. 8A is a schematic top view of the sealing substrate (second substrate) 4 before bonding. As shown in FIG. 8A, the protruding portion 5b and the straight portion 5a intersect at the center of each other, and both ends of the protruding portion 5b protrude from the side surface of the straight portion 5a. FIG. 8B is a cross-sectional view schematically showing a cross section taken along line AB of FIG. In this case, as shown in FIG. 8B, the adhesive surface has a convex shape at the portion where the protruding portion 5b intersects with the straight portion 5a.

  Next, the 2nd board | substrate 4 and the 1st board | substrate 3 are bonded together by making the surface where the adhesive agent 5 was apply | coated inside. FIG. 9A is a schematic top view for explaining the spreading state of the adhesive 5 immediately after the pair of substrates including the first substrate 3 and the second substrate 4 are bonded together. FIG. 9B is a cross-sectional view schematically showing a cross section taken along the CD line in FIG. As shown in FIG. 9 (b), the adhesive 5 has the convex portion on the surface of the adhesive contacting the first substrate 3 first.

  When the first substrate 3 and the second substrate 4 are pressed from the state of FIG. 9B, the contact portion between the adhesive 5 and the first substrate 3 is the point contact between the first substrate 3 and the adhesive 5 described above. Since it spreads from the part, it is possible to prevent air bubbles caused by voids generated when the undulating adhesive surface and the first substrate 3 are bonded.

  As a method of applying the adhesive 5, a straight portion 5a is applied, and then a shape having protrusions at both ends in a direction intersecting the straight portion 5a, for example, a protrusion 5b is applied linearly. Also good.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.

  First, the structure of an organic EL panel manufactured using the sealing method according to the present embodiment will be described with reference to a schematic cross-sectional view shown in FIG.

2-1. Overall Configuration of Organic EL Panel FIG. 10 is a schematic cross-sectional view for explaining the configuration of an organic EL panel manufactured using the sealing method according to the present embodiment.

  Referring to FIG. 10, the organic EL panel 20 is configured by bonding an organic EL substrate 3 and a sealing sealing substrate 4 with a first adhesive 14 and a second adhesive 15 for sealing. Has been.

  The organic EL substrate 3 electrically connects a plurality of organic EL elements 2, 2,..., An external circuit, and the organic EL element 2 on a TFT substrate 6 on which driving TFTs are disposed. A terminal portion 16 for sending an electric signal to the EL element 2 is arranged. Further, the pixel portion 31 is constituted by the entire set of a plurality of organic EL elements 2 formed on the TFT substrate 6.

  As shown in the figure, the organic EL substrate 3 and the sealing substrate 4 are formed by the second adhesive 15 on the pixel portion 31 and between the pixel portion 31 and the terminal portion 16 by the first adhesive 15. It is sealed with an adhesive 14. Here, the second adhesive 15 is made of a material different from that of the first adhesive 14 and has a viscosity lower than that of the first adhesive 14.

  The first adhesive 14 and the second adhesive 15 are the same as the adhesive 5 in the first embodiment. However, when the sealing substrate 4 having a color filter or a CCM (color conversion layer) is used, since the ultraviolet light cannot pass through the filter portion, the second adhesive 15 is an ultraviolet curable type, a visible light curable type, a heat A curable type, a composite curable type using ultraviolet rays and heat, or a post-curing type resin using ultraviolet rays is used. As the first adhesive 14, a thermosetting type, a visible light curable type, or a post-curing type using ultraviolet rays is used. A mold resin or the like is used.

  As the second adhesive 15, one having a viscosity smaller than that of the first adhesive 14 is used. Specifically, the second adhesive 15 preferably has a viscosity of 0.001 to 10 Pa · s, and the first adhesive 14 preferably has a viscosity of 10 to 500 Pa · s.

  Furthermore, the ratio of the viscosity of the first adhesive to the viscosity of the second adhesive is more preferably 24 or more.

The first adhesive 14 may be a material obtained by adding a filler or a gap agent to the above material. For example, the filler added to the first adhesive 14 is an inorganic material such as SiO _X (silicon oxide), SiON (silicon oxynitride) or SiN (silicon nitride), or Ag (silver), Ni (nickel) or A metal material such as Al (aluminum) may be used. The first adhesive 14 to which the filler is added has improved viscosity and moisture resistance as compared to the first adhesive 14 to which no filler is added. As the gap agent added to the first adhesive 14, a resin or the like is used in addition to the material used for the filler. By adding a gap agent to the first adhesive 14, the thickness of the first adhesive 14 layer can be made uniform. Moreover, you may use the said filler as a gap agent.

  Since the other points are the same as those in the first embodiment, description thereof is omitted.

2-2. Features of the present embodiment A method of manufacturing the organic EL panel shown in FIG. 10 using the sealing method according to the present embodiment will be described below.

  FIG. 11A is a schematic top view of the sealing substrate 4 (an example of the second substrate in the present invention) 4 before being bonded. FIG. 11B is a schematic top view of an organic EL substrate (an example of a first substrate in the present invention) 3 provided with a pixel portion 31 including an organic EL element and a terminal portion 16. The terminal part 16 is a part which electrically connects an organic EL element and an external circuit, and transmits an electrical signal to the organic EL element. The first substrate 3 and the second substrate 4 correspond to the organic EL substrate 3 and the sealing substrate 4 in FIG. 10, respectively.

  In the present embodiment, the first adhesive 14 is applied in a linear shape at a position corresponding to the area between the pixel portion 31 and the terminal portion 16 of the first substrate 3 on the surface of the second substrate 4. In the surface of the substrate 4, in the vicinity of the position corresponding to the center of the pixel portion 31 of the first substrate 3, the second bonding is performed in a shape having a straight portion 15 a and a protruding portion 15 b protruding in a direction intersecting the straight portion. Agent 15 is applied. The intersection of the straight line portion 15a and the protruding portion 15b is preferably set near a position corresponding to the center of the pixel portion 31 of the first substrate 3. The longitudinal width of the second adhesive 15 is set so that the pixel portion 31 is completely covered in a sealed state. The longitudinal width of the first adhesive 14 is set so that the second adhesive 15 does not spread to the terminal portion 16 in a sealed state. For example, the width in the longitudinal direction of the first adhesive 14 is set longer than the width in the longitudinal direction of the second adhesive 15.

  Next, the 2nd board | substrate 4 and the 1st board | substrate 3 are bonded together by making the surface where the 2nd adhesive agent 15 was apply | coated inside. 12 to 15 show that when the first substrate 3 and the second substrate 4 are pressed, the first adhesive 14 and the second adhesive 15 spread between the first substrate 3 and the second substrate 4. It is a typical top view which shows a mode that it goes.

  When the first substrate 3 and the second substrate 4 are bonded together, the first adhesive 14 has a higher viscosity than the second adhesive 15 and therefore hardly spreads. On the other hand, the 2nd adhesive agent 15 spreads in the longitudinal direction (direction of arrow M) of the linear part 15a, and the protrusion direction (arrow L direction) of the protrusion part 15b (FIG. 12). In the second adhesive 15, the protruding portion 15 b acts as a guide in the direction of the arrow L, the second adhesive 15 spreads in the protruding direction from the portion where the protruding portion 15 b is formed, and the first adhesive 15 The central portion 14 a in the longitudinal direction of the adhesive 14, and the first substrate 3 and the second substrate 4 first reach the central portion 41 a of the side 41 that faces the first adhesive 14. For this reason, voids remain at the four corners of the pair of substrates 3 and 4 at this stage (FIG. 13).

  When the pair of substrates 3 and 4 are further pressed, the second adhesive 15 further spreads in the direction of the arrow L and the direction of the arrow M on the first substrate 3 and the second substrate 4. Moreover, since the 1st adhesive agent 14 hardly spreads, it does not contact the terminal part 16. Furthermore, since the viscosity of the second adhesive 15 is lower than that of the first adhesive 14, the second adhesive 15 does not spread in the direction of the terminal portion 16 beyond the position of the first adhesive 14. That is, the first adhesive 14 blocks the second adhesive 15. Further, in the vicinity of the first adhesive 14, the second adhesive 15 spreads in the direction of the arrow M along the first adhesive 14. Thereafter, as shown in FIG. 14, the second adhesive 15 spreads so as to leave the four corners of the first substrate 3 and the second substrate 4. That is, the gaps 17 are pushed out at the four corners.

  Further, when the first substrate 3 and the second substrate 4 are pressed, the second adhesive 15 spreads to the four corners of the first substrate 3 and the second substrate 4 as shown in FIG. The first substrate 3 and the second substrate 4 can be bonded without generating bubbles between the substrate 3 and the second substrate 4. That is, according to the present embodiment, the adhesive 15 spreads from the central portions of the first substrate 3 and the second substrate 4 in the directions of the four corners, so that air is interposed between the first substrate 3 and the second substrate 4. Therefore, the first substrate 3 and the second substrate 4 can be bonded to each other without generating bubbles due to the void.

  Further, even if the first substrate 3 and the second substrate 4 are pressed, the first adhesive 14 has a high viscosity and hardly spreads, so that the first substrate 3 and the second substrate 4 do not contact the terminal portion 16. The substrate 4 can be bonded. Furthermore, since the second adhesive 15 has a lower viscosity than the first adhesive 14 and does not spread beyond the position of the first adhesive 14, the second adhesive 15 does not contact the terminal portion 16 and the second substrate 3. The substrate 4 can be bonded.

  When the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 is 24 or more, the first substrate 3 and the second substrate 4 are pressed to press the first substrate 3 and the second substrate 4. In the step of spreading the first adhesive 14 and the second adhesive 15 between the first substrate and the second substrate, the second adhesive 15 is more reliably aligned with the first adhesive 14. Generation of bubbles can be prevented. Further, the second adhesive 15 can be prevented from coming into contact with the terminal portion beyond the first adhesive 14, and the second adhesive 15 can be prevented between the first substrate 3 and the second substrate 4. When the first adhesive 14 is pushed by the second adhesive 15 and is deformed to the terminal part 16 side, the first adhesive 14 can be prevented from adhering to the terminal part 16.

  The step of applying the first adhesive 14 and the second adhesive 15, the step of bonding the first substrate 3 and the second substrate 4, the step of pressing the pair of substrates 3 and 4 and spreading the adhesive May be performed under reduced pressure or atmospheric pressure, respectively.

  In addition, the protrusion part 15b of the 2nd adhesive agent 15 should just be apply | coated to the shape which has a protrusion part in the direction which cross | intersects the linear part 15a of the 2nd adhesive agent 15, The length of this protrusion part is not ask | required However, the higher the viscosity of the first adhesive 14, the more the protrusion 15 b of the second adhesive 15 can be applied to the vicinity of the first adhesive 14.

  Further, the first adhesive 14 and the second adhesive 15 may be applied by patterning in the above shape using a mask, may be applied by patterning by screen printing, or may be applied by a dispenser. .

  Also, as a method of applying the second adhesive 15, as in the case of the first embodiment, the protrusion 15b is applied in a shape having protrusions at both ends, for example, linearly, and then the protrusion 15b. The straight part 15a may be applied linearly in the direction intersecting with the line.

  Further, the shape of the first adhesive 14 is such that the pixel portion 31 is completely covered with the second adhesive 15 without being in contact with the terminal portion 16 in a sealed state, and the second adhesive is used. 15 may be any shape that does not contact the terminal portion 16.

  Moreover, the viscosity of the 1st adhesive agent 14 should just be a viscosity which does not contact the terminal part 16 by stopping the expansion of the 2nd adhesive agent 15 in the sealed state.

  Moreover, in the above, the case where the 1st adhesive agent 14 was apply | coated to the position corresponding between the pixel part 31 and the terminal part 16 of the 1st board | substrate 3 among the surfaces of the 2nd board | substrate 4 was demonstrated. However, a third adhesive is applied in a linear shape to a position on the surface of the second substrate 4 facing the first adhesive 14 across a position corresponding to the pixel portion 31 of the first substrate 3. Is preferred.

  As described above, when the third adhesive is applied in addition to the first adhesive 14 and the second adhesive 15, when the first substrate 3 and the second substrate 4 are pressed, Since the surface of the second substrate 4 is not inclined with respect to the surface of the first substrate 3, the surface of the second substrate 4 and the surface of the first substrate 3 can be bonded in parallel. Therefore, an organic EL display with better display quality can be produced.

  The third adhesive preferably has the same viscosity as that of the first adhesive 14 and is applied to the same height as that of the first adhesive 14. More preferably, the same material as the first adhesive 14 is used as the third adhesive.

  In addition, as the third adhesive, a filler added with the same filler or gap agent as the first adhesive 14 may be used.

  Below, the Example which produced the organic electroluminescent panel 1 using the sealing method of said Embodiment 1 is shown.

  Organic EL elements 2, 2,... Were formed on the TFT substrate 6 to produce an organic EL substrate 3. FIG. 16A is a top view schematically showing a state in which the adhesive 5 is applied to the surface of the sealing substrate 4. Here, in FIG. 16A, two directions orthogonal to each other are defined as an X direction and a Y direction. The X direction and the Y direction are directions parallel to the surface of the sealing substrate 4. The size of the sealing substrate 4 is 40 mm long × 45 mm wide. FIG. 16B is a top view schematically showing the positions of the regions of the organic EL substrate 3 and the pixel portion 31 formed on the surface thereof. The size of the organic EL substrate 3 is 40 mm long × 45 mm wide, and the size of the pixel unit 31 is 27 mm long × 37 mm wide.

  On the surface of the sealing substrate 4 on the side where the color filters 12R, 12G, and 12B and the black matrix 13 are disposed, as shown in FIG. 16A, an ultraviolet curable epoxy resin is used as the adhesive 5 and a dispenser is used. Thus, it was applied linearly in the Y direction as a vertical line portion 5d, and applied in a straight line in the X direction as a horizontal line portion 5c. Specifically, the vertical line portion 5d and the horizontal line portion 5c were applied by a dispenser having a discharge port diameter of 0.4 mmφ under atmospheric pressure in a depressurizable chamber. Here, the vertical line portion 5d is applied at a speed of 30 mm / sec at a discharge pressure of 0.05 MPa, and the horizontal line portion 5c is applied in four types of application conditions shown in Table 1 (for example, the application condition 1 is a speed of 20 mm / sec). Then, it was applied at a discharge pressure of 0.1 MPa. The length of the vertical line portion 5d was 10 mm in all four application conditions.

  Next, the sealing substrate 4 coated with the adhesive 5 and the organic EL substrate 3 were bonded together under a reduced pressure of 0.8 atm in a chamber capable of reducing the pressure. At the time of such bonding, the organic EL elements 2, 2... Disposed on the organic EL element substrate 3 and the color filters 12R, 12G, and 12B disposed on the sealing substrate 4 are in corresponding positions. In addition, bonding was performed while performing alignment with a CCD camera or the like.

  Next, the inside of the chamber was pressurized to 1 atm and held at this pressure for 1 minute, thereby pressing the sealing substrate 4 and the organic EL substrate 3. Thereafter, the adhesive 5 was cured by irradiating the sealing substrate 4 and the organic EL element substrate 3 bonded with the adhesive 5 with ultraviolet rays under predetermined conditions. Next, the bonded substrate was taken out from the chamber.

  It shows in Table 1 about the application | coating conditions of the adhesive agent 5 which concerns on the horizontal line part 5c, and the result of having confirmed the sealing state in the organic electroluminescent panel 1 after bonding.

  In the coating conditions 1 to 4, the coating amount of the adhesive 5 in the horizontal line portion 5c increases in the order of 1, 2, 3, and 4. Under the coating conditions 1, 2, and 3, the adhesive 5 did not spread to the entire sealing substrate 4 and the organic EL element substrate 3 under the above pressing conditions, and voids remained at the four corners of the substrate. On the other hand, under the application condition 4, the adhesive 5 spreads to the entire sealing substrate 4 and the organic EL element substrate 3 under the above pressing conditions.

  When the organic EL panel 1 produced under the coating condition 4 was confirmed under an optical microscope, no bubbles were found in the entire organic EL panel 1.

  In the above example, the sealing substrate 4 coated with the adhesive 5 and the organic EL substrate were bonded under reduced pressure, but similar results were obtained even when the bonding was performed under atmospheric pressure.

  As described above, by appropriately adjusting the amount of the adhesive, it was possible to produce an organic EL panel without bubbles by using the present invention.

  Furthermore, using the organic EL panel produced by the above method, an organic EL display having no bubbles and good display quality could be produced.

  Next, examples in which the organic EL panel 20 is manufactured using the sealing method of the second embodiment will be described below.

  Organic EL elements 2, 2,... Were formed on the TFT substrate 6 to produce an organic EL substrate 3. FIG. 17A is a top view schematically showing a state in which the first adhesive 14 and the second adhesive 15 are applied to the surface of the sealing substrate 4. Here, in FIG. 17A, two directions orthogonal to each other are defined as an X direction and a Y direction. The X direction and the Y direction are directions parallel to the surface of the sealing substrate 4. The size of the sealing substrate 4 is 40 mm long × 45 mm wide. Here, the size of the terminal portion 16 is 2 mm long × 30 mm wide, and the terminal portion 16 is disposed along the long side of the sealing substrate 4. FIG. 17B is a top view schematically showing the position of the region of the organic EL substrate 3 and the pixel portion 31 formed on the surface thereof. The size of the organic EL substrate 3 is 40 mm long × 45 mm wide, and the size of the pixel unit 31 is 27 mm long × 37 mm wide. In addition, the pixel unit 31 is disposed so that the two long sides facing each other are located 4 mm and 9 mm from the two long sides facing the organic EL substrate 3, respectively.

  By using a dispenser on the surface of the sealing substrate 4 on the side where the color filters 12R, 12G, and 12B and the black matrix 13 are disposed, as shown in FIG. As the agent 14, an ultraviolet curable epoxy resin having a viscosity of 170 Pa · s in which a gap agent made of spheres (beads) made of a resin having a diameter of 10 μm was dispersed was applied. The first adhesive 14 was applied at a position 5 mm in the Y direction from the long side of the sealing substrate 4. Next, an ultraviolet curable epoxy resin having a viscosity of 4.5 Pa · s is applied as the second adhesive 15 in a straight line like a vertical line portion 15d in the Y direction by using a dispenser, and a horizontal line in the X direction. The coating was applied linearly as in the portion 15c. Specifically, the vertical line portion 15d and the horizontal line portion 15c were applied by a dispenser having a discharge port diameter of 0.4 mmφ under atmospheric pressure in a depressurizable chamber. Here, the vertical line portion 15d is applied at a speed of 30 mm / sec at a discharge pressure of 0.05 MPa, and the horizontal line portion 15c is applied in four types of application conditions shown in Table 1 (for example, the application condition 1 is a speed of 20 mm / sec). Then, it was applied at a discharge pressure of 0.1 MPa. Note that the length of the vertical line portion 15d was 10 mm under all four types of coating conditions.

  Next, the sealing substrate 4 coated with the first adhesive 14 and the second adhesive 15 and the organic EL substrate 3 were bonded together under a reduced pressure of 0.8 atm in a chamber capable of reducing the pressure. At the time of such bonding, the organic EL elements 2, 2... Disposed on the organic EL element substrate 3 and the color filters 12R, 12G, and 12B disposed on the sealing substrate 4 are in corresponding positions. In addition, bonding was performed while performing alignment with a CCD camera or the like.

  Next, the inside of the chamber was pressurized to 1 atm and held at this pressure for 1 minute, thereby pressing the sealing substrate 4 and the organic EL substrate 3. Thereafter, the first adhesive is obtained by irradiating the sealing substrate 4 and the organic EL element substrate 3 bonded together by the first adhesive 14 and the second adhesive 15 with ultraviolet rays under predetermined conditions. 14 and the second adhesive 15 were cured. Next, the bonded substrate was taken out from the chamber.

  The application condition of the second adhesive 15 related to the horizontal line portion 15c is the same as the application condition of the adhesive 5 related to the horizontal line part 5c in Example 1, and the sealing state in the organic EL panel 20 after bonding was confirmed. The results were as shown in Table 1 as in Example 1.

  In the coating conditions 1 to 4, the amount of the second adhesive 15 applied to the horizontal line portion 15c increases in the order of 1, 2, 3, and 4. Under the coating conditions 1, 2, and 3, the second adhesive 15 did not spread to the entire sealing substrate 4 and the organic EL element substrate 3 under the above pressing conditions, and voids remained at the four corners of the substrate. On the other hand, under the application condition 4, the second adhesive 15 spreads to the entire sealing substrate 4 and the organic EL element substrate 3 under the above pressing conditions.

  When the organic EL panel 20 produced under the coating condition 4 was confirmed under an optical microscope, no bubbles were found in the entire organic EL panel 20.

  In the above example, the sealing substrate 4 coated with the first adhesive 14 and the second adhesive 15 and the organic EL substrate are bonded together under reduced pressure. Such bonding is performed under atmospheric pressure. The same result was obtained.

  As described above, by appropriately adjusting the amount of the adhesive, it was possible to produce an organic EL panel without bubbles by using the present invention.

  Furthermore, using the organic EL panel produced by the above method, an organic EL display having no bubbles and good display quality could be produced.

  Subsequently, in the above-described Example 2, the organic EL panel 20 is changed by using the sealing method of the above-described Embodiment 2 while changing the viscosity of the first adhesive 14 and the viscosity of the second adhesive 15. The Example which manufactured this is shown.

  In the present embodiment, the second adhesive 15 according to the horizontal line portion 15c is applied under the condition 4 among the four application conditions shown in Table 1, and several types of the first adhesive 14 and the second adhesive having different viscosities are applied. The same as Example 2 except that the agent 15 was used.

  Table 2 shows the viscosity of the first adhesive 14 and the second adhesive 15 and the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 used in this example.

Here, as the first adhesive 14, a gap material made of SiO _{2 having} a particle diameter of 5 μm for height adjustment in an epoxy-based ultraviolet curable resin (manufactured by ThreeBond Co., Ltd .: 3112); Viscosity was adjusted by changing the addition amount of the filler using a filler added with a filler made of 5 μm SiO ₂ (manufactured by Tatsumori Co., Ltd .: MP-15F). Specifically, the filler addition amount was increased when obtaining a high viscosity adhesive, and the filler addition amount was reduced when obtaining a low viscosity adhesive.

  Moreover, 2-1, 2-2 and 2-3 of the second adhesive 15 shown in Table 2 are commercially available adhesives of different materials, and 2-1 and 2-2 are acrylic ultraviolet curable resins. (3043B and 3006, manufactured by ThreeBond Co., Ltd., respectively) 2-3 have different viscosities by using an epoxy ultraviolet curable resin (manufactured by ThreeBond: 3112).

  In addition, the viscosity of the 1st adhesive agent 14 and the 2nd adhesive agent 15 measured each viscosity in 25 degreeC using the B-type viscosity meter (Toki Sangyo Co., Ltd. product: BH).

  The organic EL substrate 3 and the sealing substrate 4 were bonded together and pressed through the first adhesive 14 and the second adhesive 15 shown in Table 2 in the same manner as in Example 2.

  Next, the organic EL substrate 3 and the sealing substrate 4 were bonded and pressed, and the organic EL panel 20 was confirmed under an optical microscope. As a result, the organic EL panel 20 manufactured under the conditions where the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 is 24, 50, 100, 220, 222, 455, 2000 is organic. No bubbles were found in the entire EL panel 20. In this case, when the organic EL substrate 3 and the sealing substrate 4 are bonded and pressed, the vertical line portion 15d of the second adhesive 15 is the first adhesive 15 in the vicinity of the first adhesive 14 as shown in FIG. The first adhesive 14 is pressed by contacting the longitudinal central portion 14a of the adhesive 14, but since the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 is high, the first adhesion The agent 14 does not deform and blocks the first adhesive 14 from spreading in the direction of the terminal portion 16. Then, the vertical line portion 15 d of the second adhesive 15 spreads in the direction of the arrow M in FIG. 18 along the first adhesive 14. Further, the horizontal line portion 15 c of the second adhesive 15 spreads in the direction of the arrow L. As a result, the second adhesive 15 spreads to extrude voids at the four corners. Therefore, for the organic EL panel 20 manufactured under the conditions where the viscosity ratio of the first adhesive 14 to the viscosity of the second adhesive 15 is 24, 50, 100, 220, 222, 455, 2000, the organic EL panel 20 The organic EL panel 20 can be produced without generating bubbles in the entire panel 20.

  On the other hand, bubbles were found in the organic EL panel 20 manufactured under the conditions where the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 was 11 and 23. FIG. 19A is a schematic top view of the organic EL panel 20 manufactured under the conditions where the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 is 11 and 23. FIG. As shown in FIG. 19A, bubbles 50 are generated in a part of a portion where the first adhesive 14 and the second adhesive 15 are in contact with each other. In this case, when the organic EL substrate 3 and the sealing substrate 4 are bonded and pressed, the ratio of the viscosity of the first adhesive 14 to the viscosity of the second adhesive 15 is low. ), In the vicinity of the first adhesive 14, the vertical line portion 15 d of the second adhesive 15 contacts the longitudinal center portion 14 a of the first adhesive 14 and presses the first adhesive 14. As a result, the first adhesive 14 is deformed to the terminal portion 16 side. Further, the first adhesive 14 is deformed, so that the vertical line portion 15 d of the second adhesive 15 does not sufficiently spread in the X direction along the first adhesive 14. Moreover, in FIG. 18 etc., the edge part of the horizontal line part 15c of the 2nd adhesive agent 15 is made into the straight line for convenience, However, It has actually waved like FIG.19 (b). Before the vertical line portion 15d of the second adhesive 15 sufficiently spreads in the X direction along the first adhesive 14, the first adhesion of the edge portions of the horizontal line portion 15c of the second adhesive 15 is performed. It is considered that the bubble 15 in FIG. 19A is formed when the portion 15ca swollen to the agent 14 side comes into contact with the first adhesive 14.

  That is, if the viscosity of the first adhesive 14 with respect to the viscosity of the second adhesive 15 is 24 or more, there are no bubbles in the entire organic EL panel 20, and the first adhesive 14 and the first adhesive 14 are formed in the terminal portion 16. It was found that the organic EL panel 20 in which the second adhesive 15 does not contact can be produced.

  In the above example, the sealing substrate 4 coated with the first adhesive 14 and the second adhesive 15 and the organic EL substrate 3 are bonded together under reduced pressure. The bonding is performed under atmospheric pressure. However, similar results were obtained.

  As described above, when the viscosity of the first adhesive 14 with respect to the viscosity of the second adhesive 15 is 24 or more, there are no bubbles in the entire organic EL panel 20, and the first adhesive 14 and the terminal portion 16 An organic EL panel 20 that was not in contact with the second adhesive 15 could be produced.

  As described above, by appropriately adjusting the amount of the adhesive and the ratio of the viscosity of the first adhesive to the viscosity of the second adhesive, by using the present invention, there are no bubbles and the adhesive in the terminal portion. An organic EL panel that can be electrically connected to an external terminal without sticking was able to be produced.

  Furthermore, using the organic EL panel produced by the above method, an organic EL display having no bubbles and good display quality could be produced.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In the embodiment, the top emission configuration in which the light emission of the organic EL elements 2, 2... Is extracted from the sealing substrate 4 side has been described, but the light emission of the organic EL elements 2, 2. The technology of the present invention can also be applied to the bottom emission configuration to be extracted. Even when the technique of the present invention is applied to the configuration of bottom emission, the same effect as in the above-described embodiment can be obtained.

It is a typical step view which shows the structure of the organic electroluminescent panel which concerns on 1st Embodiment. It is a typical top view which shows the sealing method of the conventional EL panel. It is a typical top view which shows the sealing method of the organic EL element which concerns on 1st Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 1st Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 1st Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 1st Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 1st Embodiment. It is the typical top view and typical sectional view showing the sealing method of the organic EL element concerning a 1st embodiment. It is the typical top view and typical sectional view showing the sealing method of the organic EL element concerning a 1st embodiment. It is typical sectional drawing which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. It is a typical top view which shows the sealing method of the organic EL element which concerns on 2nd Embodiment. 3 is a schematic top view illustrating a method for sealing an organic EL element according to Example 1. FIG. 6 is a schematic top view showing a method for sealing an organic EL element according to Example 2. FIG. 6 is a schematic top view showing a method for sealing an organic EL element according to Example 3. FIG. 6 is a schematic top view showing a method for sealing an organic EL element according to Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Organic EL panel 2 Organic EL element 3 Organic EL element substrate 4 Sealing substrate 5 Adhesive 5a Adhesive straight part 5b Straight line protruding part 5c Adhesive horizontal line part 5d Adhesive vertical line part 14 1st 15a second adhesive 15a second adhesive linear portion 15b second adhesive protruding portion 15c second adhesive horizontal line portion 15d second adhesive vertical line portion 16 terminal portion 31 Pixel part

Claims (5)

A surface of one of the first substrate on which the organic electroluminescence element and the terminal portion are formed and the second substrate for sealing the organic electroluminescence element is formed on the surface of the organic electroluminescence element and the terminal portion. A step of linearly applying the first adhesive at a position corresponding to the intermediate portion, and a shape having a linear portion and a protruding portion protruding in a direction intersecting the linear portion at a position corresponding to the organic electroluminescence element The step of applying a second adhesive having a viscosity lower than that of the first adhesive, and pressing the first substrate and the second substrate , whereby the second adhesive becomes the first adhesive. In order to prevent contact with the terminal portion beyond the first adhesive, the first adhesive has a longitudinal width longer than a longitudinal width of the second adhesive. Agent Sealing method of an organic electroluminescent device characterized by comprising a step of sealing the organic electroluminescence element spread between the beauty second of said adhesive first substrate and the second substrate. The step of applying the second adhesive includes the step of applying the adhesive in a straight line to the surface of one of the first substrate and the second substrate, and the application of the adhesive to be applied in the linear shape. Applying the adhesive in a direction intersecting with the direction. The method for sealing an organic electroluminescent element according to claim 1, wherein a ratio of the viscosity of the first adhesive to the viscosity of the second adhesive is 24 or more. The organic electro of any one of claims 1 to 3 , wherein the step of sealing the organic electroluminescence element by pressing the first substrate and the second substrate is performed under atmospheric pressure. A sealing method of a luminescence element. A display comprising an organic electroluminescence element sealed by the method according to claim 1 .

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