JPH06290870A - Organic electroluminescence element - Google Patents

Abstract

PURPOSE:To make lump processing of a multi-contact electrode possible by forming an organic electroluminescence element through provision of at least a transparent electrode and an upper electrode on a transparent base board, and at this time, performing connection of at least either of these electrodes with a drawout lead by means of hot pressure attachment with an electroconductive adhesive. CONSTITUTION:Anodes 2 are arranged parallel at a certain spacing, and alike at a certain spacing, parallel cathodes 3 are installed perpendicular to the anodes 2, and drawout leads 8 are connected with these electrodes 2, 3, when necessity for a long time pressurizing fixation is eliminated by performing the connection through hot pressure attachment using an electrocondtuctive adhesive, and also contraction of the inter-electrode distance is made possible along with reduction of the adhesion surface thickness so that the whole element is made in a thin layer. Therein an anisotropic conductive film is used to electroconductive adhesive for hot pressure attachment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film electroluminescent device, and more particularly to a thin film electroluminescent device used for flat light sources and flat displays.

[0002]

2. Description of the Related Art An electroluminescence device is composed of an organic light emitting layer and a pair of counter electrodes sandwiching the organic light emitting layer, and the emitted light is injected from one electrode and the other electrode. The holes recombine in the light-emitting layer to excite the light-emitting body to a higher energy level, and the excited light-emitting body emits energy as light when returning to the original ground state.
In such a carrier injection type electroluminescence element, since a thin film organic compound is used as a light emitting layer, one having a high light emission intensity has been obtained. For example, U.S. Pat. No. 3,530,325 uses a single crystal anthracene or the like as a light emitter, and JP-A-59-194393 discloses a combination of a hole injection layer and an organic light-emitting layer.
63-295695 is a combination of a hole injection transport layer and an organic electron injection transport layer and Jpn. Journal of Applied Physics,
Vol. 27, No. 2, P269-271 discloses a combination of a hole transfer layer, a light emitting layer and an electron transfer layer, and the emission intensity has been improved so far.

However, in order to drive the matrix, it is necessary to draw lead wires from the electrodes, but it is not enough to improve the point that it is difficult to connect one by one and the cost is huge.

This problem has a great significance particularly when an element having a fine light emitting point is made by narrowing the interval between electrodes.

[0005]

An object of the present invention is to solve the above problems.

More specifically, it is to develop a technique capable of collectively processing multi-contact electrodes and using a fine pitch between the electrodes, for example, up to about 0.2 mm. In order to assemble an organic electroluminescence element, the connection with the lead wire can be made extremely thin compared to conductive rubber, rubber with metal wire, etc. is there.

[0007]

In an organic electroluminescence element assembly in which at least a transparent electrode and an upper electrode are provided on a transparent substrate, a conductive adhesive is used to connect at least one of the transparent electrode and the upper electrode to a lead wire. It is achieved by using thermocompression bonding.

In this case, by using the anisotropic conductive adhesive, the lead wire portion and the electrode can be simply connected to form a matrix drive system of the organic electroluminescence element at low cost.

The conditions for thermocompression bonding are a temperature of 80 ° C. to 250 ° C.
Crimping time 5 to 120 seconds, pressing force at the time of crimping is 5kg / cm ^{2 to} 100k
A suitable range is g / cm ² .

If the pressure bonding temperature, pressure and pressure bonding time are lower than the above, the adhesive strength will not be sufficient, and if it exceeds the upper limit, it will rather cause a decrease in the adhesive strength, leading to the destruction of the organic electroluminescent layer by heat. In some cases.

[0011]

A desirable mode of the organic electroluminescence device here is, for example, one described in JP-A-2-66873.

More specifically, there are the followings described in Japanese Patent Application No. 3-333517. That is, in an electroluminescence device composed of a pair of counter electrodes and a plurality of organic compound layers sandwiched by these, a layer containing an organic compound represented by the following general formula [I] and a general formula [II] ] At least one layer containing the styryl compound represented by the above is provided, and the former organic compound is used as a light emitting substance and the latter is used as a charge transporting substance.

[0013]

[Chemical 1]

[(Z1) to (Z of residue Z of general formula [I]
4), R _{1 to} R ₁₁ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted 5 groups described below; an alkyl group, a monovalent group derived from an unsaturated chain hydrocarbon, and a hetero group. Cyclic group, aryl group, group containing two or more nitrogen atoms, or styryl group, anisyl group, amino group, alkylamino group, dialkylamino group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxycarbonyl group, carboxyl A group, an acyl group, an aryloxy group, an aralkyl group, an acylamino group, an acyloxy group, a hydroxyl group, a cyano group, a nitro group, a sulfo group, a sulfonium group, and R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R ₄ , R ₆ and R ₇ , R ₇ and R ₈ , R ₈ and R ₉ , R ₉ and R ₁₀ , R ₁₀ and R ₁₁ are bonded to each other to form a substituted or unsubstituted saturated or unsaturated ring structure. form It may be in.

X in the above formula (Z5) represents a substituted or unsubstituted heterocycle. ]

[0016]

[Chemical 2]

[In the above general formula [II], R ₁₂ and R ₁₃ are
Each independently represents a hydrogen atom, a substituted or unsubstituted four groups described below; an alkyl group, a heterocyclic group, an aryl group, a monovalent group derived from an unsaturated chain hydrocarbon, R ₁₂ and R
₁₃ may combine with each other to form a substituted or unsubstituted saturated or unsaturated ring structure.

R ₁₄ is a substituted or unsubstituted three groups described below; an alkyl group, an aryl group, an alkoxy group, or-{p
_{(C 6 H 4)} -} CH = C {(- R 12) - represents (R _13)}, R ₁₂ and R ₁₃
Is as defined above.

R ₁₅ represents a hydrogen atom, the following three groups which are substituted or unsubstituted; an alkyl group, an aryl group and an alkoxy group. Although there are various aspects in the configuration of the organic thin film electroluminescent element of the present invention, it is basically composed of a plurality of organic compound layers and a pair of counter electrodes sandwiching the layers, and specifically, a substrate. / Anode / Hole injection layer / Light emitting layer / Cathode (FIG. 2 (1)), Substrate / Anode / Light emitting layer / Electron injection layer / Cathode (FIG. 2 (2)), Substrate / Anode / Hole injection layer / Light emission Layer / electron injection layer / cathode (FIG. 2 (3)) and the like, but the present invention is not necessarily limited to this structure, and each of them includes a light emitting layer, a hole injection layer, and
A plurality of electron injection layers may be provided, and each of them may have a hole injection layer / light emitting layer, a light emitting layer / electron injection layer, a hole injection layer /
A structure in which a light emitting layer / electron injection layer is repeatedly laminated, a mixed layer of an electron injection material and a light emitting material between the light emitting layer and the electron injection layer, and a hole injection material between the hole injection layer and the light emitting layer It is also possible to provide a mixed layer of the luminescent material and the luminescent material, or to provide another layer in each.

The light emitting layer is formed by a vapor deposition method, a spin coating method, a casting method or the like, and its film thickness is preferably 10 to 1000 nm, more preferably 20 to 150 nm. The hole injection layer is formed by a vapor deposition method, a spin coating method, a casting method or the like, and its film thickness is preferably 10 to 1000 nm, more preferably 40 to 20 nm.
It is 0 nm. The electron injection layer is formed by a vapor deposition method, a spin coating method, a casting method or the like, and its film thickness is preferably 10 to 1000 nm, more preferably 30 to 200 nm.

The substrate 1 is made of soda glass, non-fluorescent glass,
Glass plates such as phosphoric acid-based glass and boric acid-based glass, quartz, acrylic resins, styrene-based resins, polycarbonate-based resins, epoxy-based resins, polyethylene, polyester, silicone-based resins and other plastic plates and plastic films, alumina and other metal plates And a metal foil or the like is used.

The anode 2 preferably has a work function larger than 4 eV, such as carbon, aluminum, vanadium,
Metals such as iron, cobalt, nickel, chromium, copper, zinc, tungsten, silver, tin, platinum and gold and their alloys, tin oxides such as zinc oxide, indium oxide, ITO and NESA or indium tin oxide-based composites A compound, a compound such as copper iodide, a mixture of an oxide and a metal such as ZnO: Al and SnO ₂ : Sb, and a conductive polymer such as poly (3-methylthiophene), polypyrrole and polyaniline can be used. The film thickness is preferably 10 to 1000 nm, more preferably 10 to 200 nm.

The cathode 3 preferably has a work function smaller than 4 eV, and magnesium, calcium, strontium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, ytterbium, ruthenium, manganese, aluminum, silver,
Metals such as tin and lead, alloys thereof, aluminum / aluminum oxide composites and the like are used. Particularly, magnesium metal or ytterbium metal and alloys thereof are preferable. The film thickness is preferably 10 to 1000 nm, more preferably 10
~ 900 nm.

At least one of the anode 2 and the cathode 3 is transparent or semitransparent with a transmittance of 10% or more, and when only the anode 2 is transparent or semitransparent with a transmittance of 10% or more, the substrate 1 is also. It is preferably transparent or translucent.

Specific examples of the light emitting substance used in the light emitting layer 4 include oxinoid compounds (JP-A-63-295695 and JP-A-2-155) in addition to the organic compounds represented by the above general formula.
95, No. 2-66873, etc.), perylene compounds (“Soluble Perylene Fluorescent Dyes with Photo
stability, vol.115, P2927 (1982) "," Jpn. Journalo
f Applied Physics, vol.27, No2, L269 (1988) "," B
ull.Chem.Soc.Jpn.vol.25, L411 (1952) ”, European Patent 55
3,353A1, JP-A-55-36849, JP-A-57-51781, JP-A-2-66873, JP-A-2-196885, JP-A-2-288188, JP-A-3-791, etc.), coumarin Compound (JP-A-57-51781
No., those described in JP-A-2-66873, JP-A-3-792, etc.),
Azacoumarin compounds (described in JP-A-3-792, etc.), oxazole compounds (described in US Pat. No. 3,257,203, JP-A-3-93763, 3-162482, 2-220396, etc.), oxa Diazole compound (U.S. Pat.
447, those described in JP-A-2-216791, etc.), perinone compounds (described in JP-A-2-88689, 2-289676, etc.), pyrrolopyrrole compounds (JP-A-2-296891, etc.) Those described), naphthalene compounds (JP-A-57-51781)
JP-A-2-255789, JP-A-3-162485, etc.), anthracene compound (JP-A-56-46234, 57-5)
1781, JP-A-2-66873, JP-A-3-162485, etc.), fluorene compound (JP-A-54-110837, JP-A-3-162485, etc.), fluoranthene compound (special Kaihei 3-162485, etc.), tetracene compounds (JP-A-3-162485, etc.), pyrene compounds (JP-A-57-51781, JP-A-3-162485, and JP-A-3-50485).
2333 etc.), coronene compounds (JP-A-3-
162485 etc.), quinolone compounds and azaquinolone compounds (those described in Japanese Patent Application Laid-Open No. 3-162483, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. ,same
55-88065, 49-105537, 55-51086, 56-8005
No. 1, No. 56-88141, No. 57-45545, No. 54-112637, No.
55-74546, JP-A-2-220394, JP-A-3-162486, etc.), rhodamine compounds (JP-A-2-66873, JP-A-3-66873,
-188189), chrysene compounds (described in JP-A-57-51781, JP-A-3-502333, etc.),
Phenanthrene compounds (described in JP-A-57-51781, etc.), cyclopentadiene compounds (described in JP-A-2-289675, etc.), stilbene compounds (US Pat.
6,429, JP-A-57-51781, 61-210363, 61-228.
No. 451, No. 61-14642, No. 61-72255, No. 62-47646,
62-36674, 62-10652, 62-30255, 60-934
454, 60-94462, 60-174749, 60-175052
No. 63-149652, Japanese Patent Laid-Open No. 1-173034, 1-200262
No. 1-245087, etc.), diphenylquinone compound (“Polymer Preprints, Japan, vol.37, p681
(1988) ", those described in JP-A-3-152184, etc.), styryl compounds (JP-A 1-245087, 2-209988, 2-
222484, No. 2-247278, etc.), butadiene compounds (U.S. Pat. No. 4,356,429, JP-A-57-51781, etc.), dicyanomethylenepyran compounds (JP-A-2-66873, 3-162481, etc.), dicyanomethylene thiopyran compound (JP-A-2-66873,
No. 3-162481), fluorescein compounds (such as those described in JP-A-2-66873), pyrylium compounds (such as those described in JP-A-2-66873), thiapyrylium compounds (JP-A-2 -66873), selenapyrylium compounds (described in JP-A-2-66873, etc.), telluropyrylium compounds (JP-A-2-66).
873) and the like, aromatic aldadiene compounds (described in JP-A-2-220393, etc.), oligophenylene compounds (described in JP-A-3-16284, etc.), thioxanthene compounds (JP-A-2- 3-177486), anthracene compound (described in JP-A-3-178942), cyanine compound (described in JP-A-2-66873), acridine compound (JP-A-57). -51781), metal complexes of 8-hydroxyquinoline compounds (described in JP-A Nos. 2-8287 and 2-8290, etc.), metal complexes of 2,2'-bipyridine compounds (special Kaihei 2-82
88, 2-8289, etc.), Schiff salt and III
Complexes with group metals (described in JP-A 1-297490, etc.), oxine metal complexes (described in JP-A 3-176993, etc.), rare earth complexes (JP-A-1-256584, 1-282291)
Fluorescent substances such as those described in No. 1) can be used.

Specific examples of the hole injecting compound having a hole transporting ability used in the hole injecting layer 5 include triazole derivatives (those described in US Pat. No. 3,112,197 etc.) in addition to the organic compound represented by the above general formula. , Oxadiazole derivatives (described in US Pat. No. 3,189,447, etc.), imidazole derivatives (described in Japanese Patent Publication No. 37-16096, etc.), polyarylalkane derivatives (US Pat.
615,402, 3,820,989, 3,542,544, Japanese Patent Publication 45-
555, 51-10983, JP-A-51-93224, 55-17105
No. 56, No. 56-4148, No. 55-108667, No. 56-36656, No. 55
-156953), pyrazoline derivatives and pyrazolone derivatives (US Pat. Nos. 3,180,729 and 4,278,746).
JP, 55-88064, 55-88065, 49-105537
No. 55, No. 55-51086, No. 56-80051, No. 56-88141, No. 57.
-45545, 54-112637, 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,40)
No. 4, Japanese Patent Publication No. 51-10105, No. 46-3712, No. 47-25336,
JP-A-54-53435, JP-A-54-110536, JP-A-54-119925, etc.), arylamine derivatives (US Pat.
7,450, 3,180,703, 3,240,597, 3,658,520
No., No. 4,232,103, No. 4,175,961, No. 4,012,376,
JP-B-49-35702, 39-27577, JP-A-55-144250
Nos. 56-223437, West German Patent 1,110,518, etc.), amino-substituted chalcone derivatives (US Patent 3,52
6,501), oxazole derivative (described in US Pat. No. 3,257,203), styrylanthracene derivative (described in JP-A-56-46234), fluorenone derivative (JP-A-54-110837). No. 3,717,462) and hydrazone derivatives (US Pat. No. 3,717,462).
No. 54-59143, 55-52063, 55-52064,
55-46760, 55-85495, 57-148749, JP-A-3
-136059, 3-138654, etc.), stilbene derivatives (JP-A 61-210363, 61-228451, 61)
-14642, 61-72255, 62-47646, 62-36674
No. 62, No. 62-10652, No. 62-30255, No. 60-934454, No. 6
0-94462, 60-174749, 60-175052, 63-1496
52, those described in JP-A Nos. 1-173034 and 1-200262, etc.), porphyrin compounds (US Pat. No. 3,935,031,
4,356,429, JP-A-63-295695, JP-A-2-12795, etc.), aromatic tertiary amine compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27).
033, 54-58445, 54-149634, 54-64299,
55-79450, 55-144250, 56-119132, 61-2
No. 95558, No. 61-98353, No. 63-295695, JP 1-2433
Nos. 93 and 3-111485, etc.), butadiene compounds (those described in JP-A-3-111484, etc.), polystyrene derivatives (those described in JP-A-3-95291, etc.), hydrazone derivatives ( Those described in JP-A-3-137187, etc.), triphenylmethane derivatives, tetraphenylbenzidine derivatives (compounds described in JP-A-3-54289, etc.), and the like can be used, but particularly preferably, These are porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds.

Specific examples of the electron injecting compound having an electron transporting ability used in the electron injecting layer 6 include nitro-substituted fluorenone derivatives, thiopyrandioxide derivatives, and diphenylquinone derivatives (“Polymer” in addition to the organic compounds represented by the above general formula. Preprints, Japan, vol.37, No3,
P681, (1988) ", those described in JP-A-3-152184, etc.), perylene tetracarboxyl derivatives (" Jpn. Jour.
nal of Applied Physics, vol.27, No2, L269 (1988) ''
“Bull. Chem. Soc. Jpn., Vol. 25, L411 (1952)” and the like), anthraquinodimethane derivative (JP-A-57)
-149259, 58-55450, 61-225151, 61-13375
No. 0, No. 63-104061, etc.), Fluorenylidene methane derivative (JP-A-60-69657, 61-143764)
No. 61-148159, etc.), anthrone derivatives (such as those described in JP-A Nos. 61-225151 and 61-233750), and oxadiazole derivatives (JP-A-3-79692). Compounds such as those described above), perinone derivatives (described in JP-A-2-289676, etc.), quinoline complex derivatives and the like can be used.

FIG. 2 shows a perspective view of an example of a light-emitting element formed by actually stacking these.

Here, the substrate 1 is glass and the anode 2 is I.
TO (Indium Tin Oxide) transparent conductive film and cathode 3
Used a MgAg alloy.

Needless to say, when the anode and the cathode are energized, only the overlapping portions of the two emit light.

The lead wire for energizing is an elaborate FPC
It is adhered as shown in FIG. 3 by using (flexible printed wiring board) or the like, but for adhering the lead wire and at least one of the transparent electrode and the upper electrode (usually the cathode) on the transparent substrate such as glass. It is thermocompression bonded with a conductive adhesive.

An anisotropic conductive adhesive film such as ThreeBond 3370, 3370C, 3370D (manufactured by ThreeBond Co., Ltd.) is used as the conductive adhesive for thermocompression bonding.

[0033]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

<Preparation of sample> IT was formed on glass as an anode.
Substrate on which O is deposited to a thickness of 150 nm (P110E manufactured by Nippon Sheet Glass Co., Ltd.)
-H-PS) was patterned into a desired shape, and then polished with water using an alumina abrasive. After washing with water, water ultrasonic cleaning for 10 minutes twice, acetone ultrasonic cleaning for 10 minutes twice,
Ultrasonic cleaning with isopropyl alcohol was performed twice for 10 minutes, and further dried with hot air at 90 ° C.

Next, the following styryl compound was put into a tungsten board (SF208, manufactured by Nippon Bucks Metal Co., Ltd.) and vacuum-deposited under a vacuum condition of 8.0 × 10 ⁻⁷ Torr at a film forming rate of 0.2 nm / sec to obtain a positive 81 nm film. A hole injection layer was formed.

[0036]

[Chemical 3]

Next, the following compounds were placed in a molybden boat (SS-1-9 manufactured by Nippon Bucks Metal Co., Ltd.) without breaking the vacuum condition, and 0.2 under a vacuum condition of 8.0 × 10 ^-7 Torr.
A 63 nm light emitting layer was laminated and vapor-deposited at a film formation rate of nm / sec.

[0038]

[Chemical 4]

On top of this, M without breaking vacuum conditions
g: Ag (10: 1 atomic ratio alloy) was vacuum-deposited at 500 nm to form a cathode.

A lead wire for connecting an external power source was bonded to the thus obtained organic thin film electroluminescent element by thermocompression bonding using a conductive adhesive.

The conceptual diagram in this case is as shown in FIG. 3 above. The ends of the anode 2 and the cathode 3 were gold-plated to a thickness of 200 nm, and Three Bond 3370C was used.

The lead wire was a polyimide film of 50 μm in which 35 μm-thick copper foil plated with gold was arranged at 0.3 mm pitch (line width 150 μm, line interval 150 μm).

The crimping was performed by using a crimping machine in which a 1.0 mm thick silicone rubber bonded to a 1.5 mm aluminum plate was fixed to a hot plate.

Table 1 shows the results of performance comparison of 14 samples prepared by changing the deposition temperature, pressure and time. At the same time, a conventional sample preparation by soldering was tried, but the adhesive strength was extremely weak, and the unevenness of the emission luminance was extremely remarkable probably because the connection state was bad.

[0045]

[Table 1]

The characteristics were evaluated according to the following criteria.

Adhesive strength: 90 ° peeling adhesive strength Tensile speed 50 mm / min × adhesive strength 1 kg / cm width or less ○ 〃 1-3 kg / cm width ◎ 〃 3 kg / cm × or more Luminance: 1000 cd / m ² at V = 10V Is obtained ○: Not obtained ×

[0048]

According to the present invention, it is not necessary to press and fix for a long time, multi-contact electrodes can be collectively processed, and an organic electroluminescence device having an extremely narrow gap can be assembled. Also, since the adhesive surface can be made extremely thin, the entire element can be made extremely thin.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of an organic electroluminescence element applied to the present invention.

FIG. 2 is a cross-sectional view showing an outline of an organic electroluminescence element applied to the present invention.

FIG. 3 is a perspective view showing an outline of thermocompression bonding of an electrode and an extraction lead wire of an organic electroluminescence element according to the present invention with an adhesive.

[Explanation of symbols]

 1. Transparent substrate 2. Anode 3. Cathode 4. Light emitting layer 5. Hole injection layer 6. Electron injection layer 7. Conductive adhesive 8. Drawer lead wire board (FPC)

Claims (2)

[Claims] 1. An organic electroluminescence device comprising at least a transparent electrode and an upper electrode provided on a transparent substrate, wherein at least one of the transparent electrode and the upper electrode is connected to a lead wire by thermocompression bonding using a conductive adhesive. An organic electroluminescence device characterized by being bonded. 2. The conditions for thermocompression bonding are a temperature of 80 ° C. to 250 ° C., a bonding time of 5 to 120 seconds, and a pressing force of 5 kg / cm ^{2 to} 100 kg / c.
The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is m ² .