JP2900938B1 - Organic thin film EL panel and manufacturing method thereof - Google Patents

Abstract

The present invention provides a reliable organic thin-film EL panel that can easily seal an organic thin-film EL element and connect a cathode and does not deteriorate the element, and a method for manufacturing the same. SOLUTION: The organic thin-film EL panel according to the present invention is an organic thin-film EL panel comprising a substrate having a hole transport layer and an organic light-emitting layer laminated between a pair of transparent or translucent opposed electrodes, at least one of which is transparent. A conductive pattern is formed inside the sealing cap that seals, the conductive pattern and the cathode terminal on the substrate are electrically connected, and the substrate and the sealing cap are fixed with a photo-curable insulating resin. It is characterized by having been done.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic thin-film EL panel and a method of manufacturing the same, and more particularly to a long-life organic thin-film EL panel in which luminance unevenness is suppressed and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, organic thin film EL devices (EL: Eiectr
In the organic thin film EL panel using the luminosity, there is a problem that luminance unevenness occurs in a screen and a product life is not sufficient. FIG. 6 is a schematic view showing an example of a conventional dot matrix organic thin film EL panel. This organic thin film EL panel 1 has an organic laminated film composed of a transparent electrode 3, a hole transport layer 4, and a light emitting layer 5 on a transparent support substrate 2, and a cathode 6 is provided in a direction perpendicular to the transparent electrode 3. The substrate is sealed by a sealing cap 7. In this organic thin film EL panel 1,
Since the voltage drop due to the wiring resistance of the cathode 6 is large, there is a deviation in the voltage applied to the EL element between the EL element near the connection portion of the flexible printed circuit board 10 and the EL element at a position away from the connection portion of the flexible printed circuit board 10. This may cause uneven brightness. Further, this luminance unevenness is more likely to occur as the display screen becomes larger.

As a countermeasure for this, there has been proposed a technique of connecting both ends of a pattern having a large wiring resistance with a wiring having a small wiring resistance (Japanese Patent Application Laid-Open No. 62-237484). In Japanese Patent Application Laid-Open No. 9-219288, as shown in FIG. 7, a double-sided substrate 16 in which a conductive pattern on one surface and a conductive pattern on the other surface are electrically connected to each other through a through-hole is used. A method has been proposed in which a substrate 12 is joined and sealed at an outer peripheral portion and a conductive pattern on one surface is connected to an anode and a cathode.

[0004]

However, in this method, when the glass substrate 12 and the double-sided substrate 16 are connected at the outer peripheral portion or when the terminal of the cathode 6 is connected to the conductive pattern 13, cream solder or solder is used. Since the connection is made by using a ball and melting in a constant temperature bath, the organic material is crystallized by the influence of heat, and there is a possibility that the life and the characteristics are deteriorated. In addition, there is a problem that the connection is complicated and the number of steps is increased due to the double connection. In view of the above points, the present invention provides a highly reliable organic thin-film EL panel that can easily seal an organic thin-film EL element and connect a cathode and does not deteriorate the element, and a method of manufacturing the same. The purpose is to:

[0005]

An organic thin film E according to the present invention is provided.
The L panel is an organic thin-film EL panel comprising a substrate in which a hole transport layer and an organic light-emitting layer are laminated between a pair of transparent or translucent opposed electrodes, at least one of which is inside a sealing cap for sealing the substrate. That the conductive pattern and the cathode terminal on the substrate are electrically connected to each other at both ends, and that the substrate and the sealing cap are fixed by a photocurable insulating resin. Features. In such an organic thin film EL panel, a conductive pattern is formed inside a sealing cap for sealing a substrate, and both ends of the pattern and a cathode terminal on the substrate are electrically connected to each other. It can be manufactured by sealing with a resin.

An organic thin-film EL panel according to the present invention is an organic thin-film EL panel comprising a substrate having a hole injection layer, a hole transport layer, and an organic light-emitting layer laminated between a pair of transparent or translucent opposed electrodes. In the thin-film EL panel, a conductive pattern is formed inside a sealing cap for sealing the substrate, and the conductive pattern and a cathode terminal on the substrate are electrically connected to both ends of the substrate. The stop cap is fixed with a photocurable insulating resin. In such an organic thin film EL panel, a conductive pattern is formed inside a sealing cap for sealing a substrate, and both ends of the pattern and a cathode terminal on the substrate are electrically connected to each other. It can be manufactured by sealing with a resin.

Further, the organic thin film EL panel according to the present invention comprises an organic thin film comprising a substrate having a hole transport layer, an organic light emitting layer, and an electron transport layer laminated between a pair of electrodes, at least one of which is transparent or translucent. In the EL panel, a conductive pattern is formed inside a sealing cap for sealing the substrate, and the conductive pattern and a cathode terminal on the substrate are electrically connected to both ends of the EL panel. The cap and the cap are fixed by a photocurable insulating resin. In such an organic thin film EL panel, a conductive pattern is formed inside a sealing cap for sealing a substrate, and both ends of the pattern and a cathode terminal on the substrate are electrically connected to each other. It can be manufactured by sealing with a resin.

[0008] In the organic thin-film EL panel as described above, luminance unevenness of panel display can be suppressed. When power is supplied to the cathode electrode from only one side of the EL element as in the conventional case, a voltage drop occurs due to the high wiring resistance of the cathode, and the emission luminance may vary depending on the position of the EL element. However, by connecting conductive patterns having low wiring resistance at both ends of the substrate, the wiring resistance of the cathode of the EL element viewed from the drive circuit side can be reduced. Further, in such an organic thin film EL panel, deterioration of the EL element can be suppressed. In the prior art, since solder is used for sealing and connection, when the solder is melted in a constant temperature bath or the like, heat may be applied to the EL element and the organic material may be degraded. Since a photocurable resin is used for sealing and connection, the influence of heat on the EL element can be avoided. Furthermore, in such an organic thin-film EL panel, since sealing and connection can be performed at once, the number of operation steps is simplified, and the number of connection points can be reduced. Further, the reliability can be improved because the wiring is in an inert gas.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to only these embodiments. FIG. 1A is a cross-sectional view showing an organic thin film EL panel according to the present embodiment, and FIG. 1B is an exploded perspective view thereof. As shown in FIG. 1, a transparent electrode 22 is formed as an anode on a transparent support substrate 21, and a hole transport layer 23 and a light emitting layer 24 are formed thereon by a vacuum deposition method. On the light-emitting layer 24, a metal having a small work function is formed as the cathode 25, thereby forming a substrate of the organic thin-film EL panel. Inside the sealing cap 26, a low-resistance conductive pattern 27 is
5 are patterned at the same pitch. The periphery of the sealing cap 26 and the transparent support substrate 21 are
9 are dispersed by a photo-curable insulating resin 28 in which they are dispersed.

Next, a method of manufacturing the organic thin film EL panel of the present embodiment shown in FIG. 1 will be described. A transparent electrode 22 made of ITO or the like is formed as an anode on a transparent support substrate 21 made of glass or the like by a sputtering method. A hole transport layer 23 is formed thereon by a vacuum evaporation method, and a light emitting layer 24 is further formed thereon by a vacuum evaporation method to form an organic laminated film. Next, a cathode 25 is formed on the organic film by using a metal having a small work function such as magnesium: silver or lithium: aluminum, or an alloy thereof, by using a resistance heating method or an electron beam heating method. Create a substrate for the EL panel.

A conductive pattern 27 is deposited on the inside of a sealing cap 26 made of a glass substrate or the like so as to have the same pitch as the cathode 25 on the transparent support substrate 21. In an inert gas atmosphere, the terminal of the cathode 25 and the position of the conductive pattern 27 are temporarily fixed and fixed, and in this state, the resin 28 is cured by irradiating ultraviolet rays to obtain the organic thin film EL panel 21.

When viewed from the cathode drive circuit side by the sealing cap 26, the flexible printed circuit board 30 is formed by the conductive pattern 27 wired inside the sealing cap 26.
Are connected to two places at both ends of the cathode 25, and E
The effective cathode line resistance of the L element is reduced, and luminance unevenness of the EL element due to wiring resistance can be suppressed.
Also, since the wiring is in the inert gas in the cap 26,
Reliability is improved. In addition, since soldering is not used for sealing, the EL element is not exposed to a high temperature, and deterioration of the element can be prevented.

[0013]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. (Embodiment 1) FIGS. 2 to 4 show a first embodiment of the present invention. As shown in FIG. 2, an ITO film was formed on a transparent support substrate 31 having a thickness of 1.1 mm by sputtering as an anode.
The transparent electrode 32 was formed by photolithography and wet etching. Sheet resistance is 15
Ω / □, and the wiring pitch was 0.3 mm. Next, this transparent support substrate 31 is fixed to a substrate holder of a vacuum evaporation apparatus, and N, N′-diphenyl-N, N′bis (α-naphthyl) is used as a hole transport layer in a resistance heating boat in the vacuum evaporation apparatus. ) -1,1-biphenyl-4,4′-diamine (hereinafter abbreviated as α-NPD), and tris (8-quinolilite) aluminum complex (hereinafter, Alq3; ), And the inside of the vacuum evaporation apparatus was evacuated to 1 × 10 ⁻⁵ Torr or less with a vacuum pump.

Thereafter, a metal mask in which the area for depositing the organic EL layer is cut out in a rectangular shape is applied to the transparent support substrate 31.
It was installed so as to be fixed to the surface. Then, the α-NPD provided below the transparent support substrate 31 and the mask
Was heated by passing an electric current through the resistance heating boat. And α-
The NPD layer 33 was deposited so as to have a thickness of about 50 nm. Thereafter, an Alq3 layer 34 was deposited to a thickness of 50 nm. Thus, the organic EL layer was formed, and the substrate shown in FIG. 2 was obtained. The α-NPD layer 33 functions as a layer for transporting holes, and the Alq3 layer 34 functions as a layer for transporting electrons and a light emitting layer. Here, α-NPD and Alq
In order to make the thickness of the deposited film 3 more uniform, a method of rotating the transparent support substrate 31 in a plane horizontal to the deposition source during the deposition can be mentioned.

Next, a shadow mask made of SUS430 was previously placed in a vacuum evaporation apparatus, and a transparent support substrate 31 having an organic EL layer formed thereon was placed on the shadow mask. The shadow mask has a stripe-shaped shielding portion and a slit portion. Then, a stripe-shaped shielding portion is formed on the transparent support substrate 31 in a direction orthogonal to the anode line. Next, magnesium was put in a resistance heating boat in a vacuum evaporation apparatus, and silver was put in another resistance heating boat, and the ratio of magnesium to silver was 10: 1.
Were deposited together at a deposition rate of Next, the transparent support substrate 3
1 is separated from the shadow mask to form a striped cathode 35 made of an alloy of magnesium and silver from organic E.
It was formed on the L layer.

Next, conductors are patterned at the same pitch as the cathode 35 inside the glass cap 36 for sealing. A stripe-shaped shielding portion is formed on the shadow mask 43,
A slit portion is provided, and a glass cap 36 is provided.
The shape is matched. As shown in FIG. 3, the stripe-shaped shielding portion of the shadow mask 43 is
Attract by magnet 44 so that it is firmly fixed on top.
Therefore, the shadow mask 43 is preferably made of a magnetic material. Next, copper was put into a resistance heating boat, heated by flowing an electric current, and copper was deposited to a thickness of 10 μm. The conductive pattern is formed by an ion plating method, a sputtering method, or the like in addition to the vapor deposition method. By separating the glass cap 36 from the shadow mask 43, a stripe-shaped conductive pattern 37 having the same pitch as the cathode 35 was formed in the glass cap 36.

Next, a photo-curable insulating resin 38 in which metal particles 39 having a particle size of about 5 μm were dispersed was uniformly applied to the electrode connecting portion of the glass cap 36 with a dispenser.
As the photocurable insulating resin 38, a modified acrylate resin was used. Further, instead of the metal particles 39, a metal bead plated with plastic beads may be used. Then, the electrode patterns of the transparent support substrate 31 and the glass cap 36 are aligned in an inert gas atmosphere such as nitrogen gas,
Pressure was applied at about g / cm ² . Ultraviolet light was irradiated from the opposite surface of the transparent support substrate 31 from the electrode while the pressure was being applied to cure the photocurable insulating resin 38. As shown in FIG. 4, the cathode 35 and the conductive pattern 37 are electrically connected by the metal particles 39, and the transparent support substrate 31 is sealed by the glass cap 36 while the gap is insulated by the photocurable insulating resin 38.
After curing, the electrodes of the transparent support substrate 31 and the glass cap 36
Are mechanically held to obtain electrical continuity. The flexible printed circuit board 40 was connected to one side of the panel thus obtained, and was driven. As a result, a panel having uniform luminance emission on all display surfaces was obtained.

(Embodiment 2) FIG. 5 shows a second embodiment of the present invention.
Shown in An ITO film having a thickness of 100 nm was formed as an anode on a transparent support substrate 51 having a thickness of 1.1 mm by sputtering, and a transparent electrode 52 was formed by photolithography and wet etching. The sheet resistance was 15Ω / □, and the wiring pitch was 0.3 mm. Next, this transparent support substrate 51 was fixed to a substrate holder of a vacuum evaporation apparatus, α-NPD was put as a hole transport layer in a resistance heating boat in the vacuum evaporation apparatus, and Alq3 was used as a light emitting layer in another resistance heating boat. And the inside of the vacuum deposition apparatus is 1 × 10 ⁻⁵ Torr by a vacuum pump.
Exhausted below.

Thereafter, a metal mask in which the area where the organic EL layer is to be vapor-deposited is cut out in a rectangular shape is attached to the transparent support substrate 51.
It was installed so as to be fixed to the surface. Then, an electric current is applied to the transparent support substrate 51 and the α-NPD resistance heating boat provided below the mask to heat the α-NPD resistance heating boat.
3 was deposited so as to have a film thickness of about 50 nm. afterwards,
An Alq3 layer 54 is deposited to a thickness of 50 nm. Next, S
A US430 shadow mask was placed in a vacuum evaporation apparatus in advance, and a transparent support substrate 51 having an organic EL layer formed thereon was placed on the shadow mask. The shadow mask has a stripe-shaped shielding portion and a slit portion. Then, a stripe-shaped shielding portion is formed on the transparent support substrate 51 in a direction orthogonal to the anode line. Next, magnesium was put in a resistance heating boat in a vacuum evaporation apparatus, silver was put in another resistance heating boat, and magnesium and silver were evaporated together at an evaporation rate of 10: 1. Next, the transparent support substrate was separated from the shadow mask to form a striped cathode 55 made of an alloy of magnesium and silver on the organic EL layer.

Next, a metal cap 56 made of SUS430 is used.
An insulating layer 61 is formed on the entire inner surface of the device from SiO or the like. A conductor is patterned on the SiO layer 61 at the same pitch as the cathode 55. The cathode 55 is used for the shadow mask.
A slit portion having a stripe-shaped shielding portion having the same pitch as that of the glass cap 56 is provided. Then, as the conductive pattern 57, copper was deposited to a thickness of 10 μm. By separating the glass cap 56 from the shadow mask, a striped conductive pattern 57 having the same pitch as the cathode 55 was formed in the cap.

Next, a photo-curable insulating resin 58 in which metal particles 59 of about 5 μm were dispersed was uniformly applied to the electrode connecting portion of the glass cap 56 with a dispenser. As the photocurable insulating resin 58, a modified acrylate resin was used.
Further, instead of the metal particles 59, plastic beads obtained by metal plating on plastic beads may be used. Then, the electrode pattern of the transparent support substrate 51 and the electrode pattern of the glass cap 56 are aligned in an inert gas atmosphere such as a nitrogen gas, and 30 kg / c.
pressurized with m ² about. While being pressurized, ultraviolet light is irradiated from the opposite surface of the panel electrode to cure the photocurable insulating resin 58.

As shown in FIG. 5, the conductive pattern 57 is electrically connected to the cathode 55 by the metal particles 59, and the gap is insulated by the photocurable insulating resin 58. You. After the curing of the resin 58, the electrodes on the transparent support substrate 51 and the electrodes on the glass cap 56 are mechanically held to obtain electrical continuity. The flexible printed circuit board 60 was connected to one side of the panel thus obtained, and was driven. As a result, a panel having uniform luminance emission on all display surfaces was obtained.

[0023]

As described in detail above, in the organic thin-film EL panel of the present invention, it is possible to suppress unevenness in panel display luminance. By connecting conductive patterns with low wiring resistance to both ends of the substrate, the EL viewed from the drive circuit side
The wiring resistance of the cathode of the device can be reduced. Further, in the organic thin film EL panel of the present invention, since a photocurable resin is used for sealing and connection, there is no influence of heat on the EL element, and deterioration of the EL element can be suppressed. Further, in the organic thin-film EL panel of the present invention, since the sealing and the connection can be performed at once, the number of operation steps is simplified, and the number of connection points can be reduced. Further, the reliability can be improved because the wiring is in an inert gas.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing an organic thin-film EL panel according to the present embodiment, and FIG. 1B is an exploded perspective view thereof.

FIG. 2 is a sectional view showing a substrate according to the first embodiment.

FIG. 3 is a sectional view showing a glass cap of the first embodiment.

FIG. 4 is a cross-sectional view illustrating an organic thin-film EL panel according to a first embodiment.

FIG. 5 is a sectional view showing an organic thin film EL panel according to a second embodiment.

FIG. 6 is a schematic view showing an example of a conventional dot matrix organic thin film EL panel.

FIG. 7 is a schematic diagram illustrating Japanese Patent Application Laid-Open No. 9-219288.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Transparent support substrate 22 Transparent electrode 23 Hole transport layer 24 Light emitting layer 25 Cathode 26 Sealing cap 27 Conductive pattern 28 Photocurable insulating resin 29 Metal particles 30 Flexible printed board

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-7-153571 (JP, A) JP-A-10-233283 (JP, A) JP-A 8-124677 (JP, A) JP-A-2- 8886 (JP, A) Japanese Utility Model 1-107898 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05B 33/00-33/28

Claims (6)

(57) [Claims] 1. An organic thin-film EL panel comprising a substrate having a hole transport layer and an organic light-emitting layer laminated between a pair of electrodes, at least one of which is transparent or translucent, wherein a sealing cap for sealing the substrate is provided. A conductive pattern is formed inside, the conductive pattern and the cathode terminal on the substrate are electrically connected to both ends, and the substrate and the sealing cap are fixed by a photocurable insulating resin. An organic thin-film EL panel characterized in that: 2. An organic thin-film EL panel comprising a substrate in which a hole transport layer and an organic light-emitting layer are laminated between a pair of electrodes, at least one of which is transparent or translucent, wherein a sealing cap for sealing the substrate is provided. A method of manufacturing an organic thin-film EL panel, comprising: forming a conductive pattern on the inside; electrically connecting both ends of the pattern and a cathode terminal on the substrate; and sealing with a photocurable insulating resin. Method. 3. An organic thin-film EL panel comprising a substrate having a hole injection layer, a hole transport layer, and an organic light-emitting layer laminated between a pair of electrodes, at least one of which is transparent or translucent, wherein the substrate is sealed. A conductive pattern is formed inside a sealing cap to be formed, the conductive pattern and a cathode terminal on a substrate are electrically connected to both ends of the sealing cap, and the substrate and the sealing cap are in a light-curable insulating state. An organic thin-film EL panel fixed by a resin. 4. An organic thin-film EL panel comprising a substrate having a hole injection layer, a hole transport layer, and an organic light-emitting layer laminated between a pair of opposed electrodes, at least one of which is transparent or translucent, wherein the substrate is sealed. Forming an electrically conductive pattern inside a sealing cap to be formed, electrically connecting both ends of the pattern and the cathode terminal on the substrate, and performing sealing with a photocurable insulating resin. A method for manufacturing a thin film EL panel. 5. An organic thin-film EL panel comprising a substrate in which a hole transport layer, an organic light-emitting layer, and an electron transport layer are laminated between a pair of opposed electrodes, at least one of which is transparent or translucent, wherein the substrate is sealed. A conductive pattern is formed inside the sealing cap, the conductive pattern and a cathode terminal on the substrate are electrically connected to both ends, and the substrate and the sealing cap are formed of a photocurable insulating resin. An organic thin-film EL panel characterized by being fixed by: 6. An organic thin-film EL panel comprising a substrate in which a hole transport layer, an organic light-emitting layer, and an electron transport layer are laminated between a pair of opposed electrodes, at least one of which is transparent or translucent, wherein the substrate is sealed. An organic thin film, wherein a conductive pattern is formed inside a sealing cap, both ends of the pattern and a cathode terminal on the substrate are electrically connected, and sealing is performed with a photocurable insulating resin. EL panel manufacturing method.