JP2005002450A - Vapor deposition method, vapor deposition head, and apparatus for manufacturing organic electroluminescent display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition method capable of reducing a manufacturing cost, a vapor deposition head and an apparatus for manufacturing an organic electroluminescent display panel using the same. <P>SOLUTION: The vapor deposition method comprises forming a thin film of a vapor deposition material on a substrate arranged to face the opening of a nozzle by supplying the evaporated vapor deposition material to the nozzle and holding the material in the nozzle by a temperature fall. The vapor deposition method has the nozzle having the opening to hold the vapor deposition material and to discharge the vaporized vapor deposition material, a temperature controller for heating and cooling the nozzle and a supplying device communicating with the nozzle to supply the vapor deposition material to the nozzle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method and a manufacturing method of an organic electroluminescence display panel including a plurality of organic electroluminescence elements.
[0002]
[Prior art]
The organic electroluminescence element utilizes an organic compound so-called organic EL material that exhibits electroluminescence (hereinafter referred to as EL) that emits light by current injection. For example, a transparent electrode of an anode and light emission of an organic EL material on a transparent substrate. One or more organic layers including layers and a cathode metal electrode are sequentially laminated. An organic EL display panel is obtained by forming a plurality of organic EL elements on a substrate in a predetermined pattern. The organic layer of each organic EL element is a single layer of a light emitting layer, or a three-layer structure of an organic hole transport layer, a light emitting layer and an organic electron transport layer, or an organic hole transport layer and a light emitting layer two layer structure, A laminated body in which an electron or hole injection layer is inserted between appropriate layers.
[0003]
An organic EL display panel, for example, a matrix display type is configured by sequentially laminating a row electrode including a transparent conductive layer, an organic layer, and a column electrode including a metal electrode layer intersecting the row electrode. The row electrodes are each formed in a strip shape and are arranged so as to be parallel to each other at a predetermined interval. The same applies to the column electrodes. As described above, the matrix display type display panel has a display region formed of a plurality of organic EL elements (light-emitting pixels) formed at intersections of a plurality of row and column electrodes. A plurality of organic EL elements in the display area are arranged in a matrix on a transparent substrate, connected as appropriate, and driven by a predetermined signal, and further, organic light emitting light of three primary colors of red R, green G and blue B can be displayed. A full-color display device can be formed by forming a display region including EL elements.
[0004]
In the manufacturing process of the organic EL display panel, since the organic layer is not suitable for the wet process, the organic layer is formed by vapor deposition.
In the conventional resistance heating vapor deposition method using a point vapor deposition source and a metal mask, a vapor deposition material 2 such as an organic material or an electrode material is placed in a boat 3 in a film deposition chamber 1 of a vacuum vapor deposition apparatus as shown in FIG. The heated and sublimated material was deposited in a predetermined pattern on the glass substrate 4 through a metal mask 5 disposed on the substrate, and an organic material or the like was selectively formed into a film. This method has the advantages of simultaneously forming and patterning an organic material layer, but has the disadvantages that it is difficult to create a metal mask, it is difficult to align the metal mask and the substrate, and the material usage efficiency is extremely poor. . When a pattern is formed on a large transparent substrate by vapor deposition, a large mask must be used, and the large mask is distorted and the pattern formation accuracy is reduced due to expansion. Adhesion was a serious problem.
[0005]
In order to avoid these problems, there is a fusion thermal transfer method. For example, an electrode pattern is formed on a transfer plate, a vapor deposition material is uniformly applied thereon, and power is supplied to the electrode pattern. A so-called mask-less attempt not using a so-called mask has been made (see Patent Document 1).
[0006]
Japanese Patent Laid-Open No. 2002-302759.
[0007]
[Problems to be solved by the invention]
However,
The technique of Patent Document 1 has a problem of an increase in cost such as an increase in the pretreatment process of the transfer plate. In addition, since the vapor deposition material remains in a portion other than the transfer pattern, there are disadvantages such as the use efficiency of the vapor deposition material is deteriorated and it takes time until the film is formed.
[0008]
Therefore, the problem to be solved by the present invention is to realize maskless vapor deposition, thereby eliminating various problems related to the mask, achieving a significant improvement in material use efficiency, and a pretreatment process of the transfer plate. An example is to provide a manufacturing apparatus and a manufacturing method of an organic EL display panel that can avoid complication and an increase in size of the manufacturing apparatus.
[0009]
[Means for Solving the Problems]
The vapor deposition method according to claim 1, wherein vaporized vapor deposition material is supplied to a nozzle, and the vapor deposition material held in the nozzle is vaporized by heating the nozzle due to a temperature drop, and the substrate is disposed to face the nozzle opening. And forming a thin film of the vapor deposition material.
[0010]
The vapor deposition head according to claim 9, wherein the vapor deposition material that holds the vapor deposition material and has an opening for discharging the vapor deposition material, a temperature controller that heats and cools the nozzle, and the vapor deposition that communicates with the nozzle and vaporizes. And a feeder for supplying material to the nozzle.
The organic EL display panel manufacturing apparatus according to claim 17, wherein a plurality of organic EL elements each including at least one organic layer including a light emitting layer sandwiched between a pair of electrodes are arranged on a substrate. Manufacturing equipment,
A plurality of nozzles having openings for holding the vapor deposition material of the organic EL element and discharging the vaporized vapor deposition material; a temperature controller for heating and cooling the nozzle; and the vapor deposition material vaporized in communication with the nozzle. A vapor deposition head having a feeder for supplying to the nozzle;
And a support mechanism for supporting the vapor deposition head so that the opening of the nozzle faces the substrate apart from the substrate.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In general resistance heating vapor deposition, vapor deposition materials once heated and sublimated flies linearly in various directions from the boat and adhere to the side wall of the deposition chamber or metal mask below the sublimation temperature. . However, the deposited vapor deposition material also flies again when the temperature exceeds the sublimation temperature. Focusing on this phenomenon, the basic principle is positively utilizing the phenomenon that the deposition material adheres to the object below the sublimation temperature. The sublimation of the deposited vapor deposition material can be performed again by controlling the temperature of the object.
[0012]
In maskless deposition, the deposition distance becomes extremely short by making the spot deposition source into a spot of about a micrometer, and providing a plurality of nozzles such as a spot deposition source, that is, fine holes, and then spraying the deposition material onto them. A metal mask is also unnecessary.
Even if nozzles such as multi-point fine holes are formed, it is necessary to open and close the multi-point nozzles in order to form a vapor deposition pattern. In the present invention, opening and closing of fine holes having a diameter of 10 μm or less is realized by temperature control of the nozzle.
[0013]
Embodiments of the present invention will be described with reference to the drawings.
An example of the manufacturing apparatus of the organic EL display panel of the present invention is shown in FIG.
As shown in FIG. 2, the display panel substrate 4 (for example, a transparent substrate such as glass or resin) and the vapor deposition head 20 correspond to the supporting mechanisms in the decompressed film forming chamber 10 of the organic EL display panel manufacturing apparatus. 12 are opposed to each other in parallel. In addition, the support mechanism 12 is provided with a feed screw 52 of a translation drive device that moves the vapor deposition head 20 and the display panel substrate 4 relatively in parallel.
[0014]
As shown in FIG. 3, the vapor deposition head 20 includes a nozzle 21 having a fine opening for discharging a vapor deposition material, and a nozzle plate 24 provided with a heating element that is a part of a temperature controller for heating and cooling them, And a supply container 25 that is a supply device that supplies the vaporized vapor deposition material communicating with the nozzle 21 to the nozzle 21. A one-dimensional vapor deposition head having a nozzle array 21a in which a plurality of nozzles 21 are arranged one-dimensionally, for example, linearly in the longitudinal direction X may be used. The nozzle plate 24 of the nozzle array 21a is narrower than the display area of the plurality of organic EL elements to be formed on the substrate 4 and extends over a part of the display area, and the area thereof is smaller than the area of the display area. It is. The vapor deposition head 20 is configured to scan relatively in a direction perpendicular to the longitudinal direction X thereof.
[0015]
As shown in FIG. 4, the vapor deposition head 20 includes a translational drive device so as to be intermittently movable in a predetermined direction Y with respect to the substrate 4. That is, an external feed screw 52 parallel to the substrate 4 rotated by the external motor 51 is provided, and the housing of the vapor deposition head 20 is screwed to the feed screw 52. The external motor 51 is connected to a motor drive circuit (not shown) and controlled in a predetermined manner.
[0016]
As shown in FIG. 4, the organic material is sublimated by heating the nozzle opening with a heating element 30 corresponding to a desired pixel at a certain position on the nozzle opening of the one-dimensional vapor deposition head 20. Vapor deposition at desired location. Then, as shown in FIG. 23, the substrate or the evaporation head is sequentially moved relative to each other, and the evaporation is repeated to form a plurality of pixel patterns on the entire surface of the substrate 4.
[0017]
As shown in FIG. 5, the supply container 25 of the vapor deposition head 20 is provided with a heater 26 for heating and keeping the inner container around and a temperature sensor 27 for monitoring the internal temperature. Using the heater 26 and the temperature sensor 27, the temperature of the entire supply container 25 is controlled. The nozzle plate 24 in which the fine hole nozzles 21 are formed is fixed to the upper portion of the supply container 25 so as to close the opening extending in the longitudinal direction.
[0018]
As shown in FIG. 6, in the nozzle plate 24, a heat insulating layer 24b made of a heat insulating material and an electrical insulating film 24c are formed in order on substantially the entire upper surface of a main body 24a made of a heat conductor. A heating element 30 is formed on the electrical insulating film 24c. As shown in FIG. 7, a pair of electrodes 31 connected to the heating element 30 and supplying current to the heating element 30 are formed on the electrical insulating film 24c with the heating element interposed therebetween. A fine hole nozzle 21 having a length and a hole diameter necessary for forming a desired vapor deposition pattern is formed at the center of the heating element 30. The diameter and length of the nozzle 21 are determined by the material, area, and thickness of the vapor deposition pattern to be formed. The heating element 30 is made of a material that efficiently generates Joule heat when a current flows.
[0019]
Next, the operation is as follows.
As shown in FIG. 8, the supply container is installed so that the nozzle 21 approaches the opposing substrate 4. The supply container 25 is heated, the vapor deposition material inside is sublimated, and the vapor deposition material 2 vaporized in the supply container is filled (FIG. 8A). In a state where the heating element is not energized by the electrodes, the nozzle 21 is naturally cooled to the sublimation temperature or lower, so the nozzle 21 holds the vapor deposition material in a so-called clogged state, and the vaporized vapor deposition material 2 inside the supply container. Does not jump out (FIG. 8B). During energization to pass a current from the electrode to the heating element, the nozzle 21 provided on the heating element generates heat due to Joule heat, the temperature exceeds the sublimation temperature, and the clogged vapor deposition material is sublimated and filled inside. At the same time, it jumps out to the counter substrate at a substantially constant angle (FIG. 8C). At this time, if a display panel substrate is installed close to the upper part of the nozzle, a vapor deposition pattern is formed. At the time of de-energization, the heat generation of the heating element stops, so it instantaneously falls below the sublimation temperature by natural cooling, the micropores are clogged with the vapor deposition material (FIG. 8B), and the vapor deposition material inside the supply container 25 does not fly. By selectively energizing the electrodes, it is possible to simultaneously form a vapor deposition pattern and pattern it. The nozzle cooling is natural cooling, but can be forced cooling using a Peltier element or the like.
[0020]
For supplying and heating power to the heating element, as shown in FIG. 2, the organic EL display panel manufacturing apparatus includes a power device 32 that selectively supplies power to the electrodes connected to the heating element 30 of the vapor deposition head. I have. Further, the manufacturing apparatus includes a second temperature sensor 33 that is connected to each heating element and detects the temperature thereof, and a temperature control unit 34 that is connected to the power device 32 and controls the temperature of the heating element according to the detected temperature. It has. For example, in the case of a plurality of heating elements, the temperature control unit 34 can control the temperatures so as to be individually different. In addition, although the 2nd temperature sensor 33 is provided for every heat generating body, when controlling the heat generating body at the same time by carrying out on-off control simultaneously, the 2nd temperature sensor 33 is used with one instead of two or more. The temperature may be monitored.
[0021]
Thus, according to the present invention, for example, the deposition material can be formed and patterned simultaneously without using a metal mask. First, since a metal mask is not used, a precise metal mask that is difficult to produce becomes unnecessary, which directly leads to cost reduction. Second, the deposition material utilization efficiency of about 3 to 5% of the conventional method is greatly improved by 50% or more.
Furthermore, in the present invention, since multi-point spot vapor deposition is performed, the distance between the vapor deposition source and the display panel substrate can be greatly shortened. As a result, the vapor deposition apparatus itself can be reduced in size, and both equipment costs and running costs can be significantly reduced. Further, it is not necessary to prepare a transfer film separately as in the case of the melt transfer method, and there is no need for facilities and processes for that purpose, which is greatly advantageous in terms of cost.
[0022]
In the present invention, the vapor deposition material supplied by vaporization is held by the micropores, the vapor deposition material held is sublimated, and the vapor is directly blown to the opposing display panel substrate. The directionality is stable, the pattern width formed on the substrate is very stable, and a pattern with a clear contour can be formed. In addition, since a fine hole nozzle provided in the heating element is used, the response is fast with respect to on / off of the current. Therefore, the amount of vapor deposition material to be skipped can be easily adjusted and the film thickness can be easily controlled, and the pattern formation time can be shortened, so that the production tact time can be shortened.
[0023]
FIG. 9 shows, from the transparent substrate side, an organic EL display panel 40 having an arrangement of an organic layer 46 including, for example, a tris (8-quinolinolato) aluminum film of a luminescent organic compound formed by an organic EL display panel manufacturing apparatus. It is a partial top view. For example, the organic layer is a single layer of the light emitting layer, or includes a hole transport layer, an electron transport layer, or an electron injection layer or a hole injection layer in addition to the light emitting layer. On the transparent substrate 4 of the organic EL display panel 40, a transparent electrode 43 made of indium tin oxide or the like is formed in advance in a stripe shape. The transparent electrodes 43 are arranged in a plurality of stripes parallel to each other. The organic material sublimated from the nozzles corresponding to the plurality of pixels according to the present invention (corresponding to the organic EL elements for each column) is applied on the transparent electrode 43 to form a pattern, and then stripes intersecting the transparent electrode A metal electrode 45 is provided. As described above, the organic EL display panel 40 includes the red (R), green (G), and blue (B) light emitting units 46 (organic EL elements) arranged in a matrix on the glass substrate 4 in a predetermined cycle. Can display a full-color image.
[0024]
The simple matrix organic EL display panel has been described. In addition, the present invention, for example, uses an active matrix display type organic EL device using a substrate on which active elements such as TFTs connected to a plurality of organic EL elements are formed in advance. It can also be applied to the manufacture of EL display panels.
FIG. 10 is a plan view of the two-dimensional vapor deposition head 20 in which the nozzle array 21a is two-dimensionally arranged in, for example, two rows. If the two-dimensional vapor deposition head 20 is used, it can vapor-deposit simply and efficiently in a short time.
[0025]
In the above embodiment, the temperature controller for the nozzle in the vapor deposition head is configured to have a heating element in contact with the nozzle, an electrode connected to the heating element, and a means for supplying power to the heating element. In the embodiment, for example, as shown in FIG. 10, the nozzle temperature controller of the vapor deposition head is configured to include a laser light beam irradiation device 60 and a light receiving unit 21 b that receives the laser light beam in contact with the nozzle 21. May be. Although the structure of the supply container 25 is the same as the above, as shown in FIG. 11, the light receiving unit 21b includes a nozzle plate 24, a base 21d made of a heat conductor formed on the heat insulating layer 24b on the main body 24a. It is formed as a projecting hollow projecting portion. The vaporized vapor deposition material is supplied to the nozzle, and the vapor deposition material is held in the nozzle by the temperature drop of the protrusion. By irradiating the nozzle 21 with a laser beam and heating the nozzle 21, the held vapor deposition material is sublimated, and a thin film of the vapor deposition material is formed on the substrate disposed opposite to the nozzle opening. In the case of this embodiment as well, the power apparatus 32, the second temperature sensor 33, and the temperature control unit 34 are provided in the manufacturing apparatus in the same manner as the configuration shown in FIG.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a conventional vapor deposition method.
FIG. 2 is a cross-sectional view schematically showing an organic EL display panel manufacturing apparatus according to an embodiment of the present invention.
FIG. 3 is a perspective view schematically showing a vapor deposition head according to an embodiment of the present invention.
FIG. 4 is a partial plan view illustrating a drive unit of the organic EL display panel manufacturing apparatus according to the embodiment of the present invention.
FIG. 5 is a cross-sectional view schematically showing a vapor deposition head according to an embodiment of the present invention.
FIG. 6 is a partial cross-sectional view illustrating the vicinity of a nozzle of a vapor deposition head that is an embodiment of the present invention.
FIG. 7 is a partial plan view for explaining the vicinity of a nozzle of a vapor deposition head according to an embodiment of the present invention.
FIG. 8 is a cross-sectional view schematically showing the operation of the vapor deposition head according to the embodiment of the present invention.
FIG. 9 is a partial plan view schematically showing an example of a light emitting pixel array of a full color organic EL display panel.
FIG. 10 is a plan view schematically showing a vapor deposition head according to another embodiment of the present invention.
FIG. 11 is a partial perspective view illustrating the vicinity of a nozzle of a vapor deposition head according to another embodiment of the present invention.
FIG. 12 is a partial cross-sectional view illustrating the vicinity of a nozzle of a vapor deposition head according to another embodiment of the present invention.
[Explanation of symbols]
4 Display Panel Substrate 10 Film Formation Chamber 12 Support Mechanism 20 Evaporation Head 21 Nozzle 21a Nozzle Array 21b Light Receiving Part 21d Base 24 Nozzle Plate 24a Main Body 24b Heat Insulating Layer 24c Electrical Insulating Film 25 Supply Container 26 Heater 27 Temperature Sensor 30 Heating Element 31 Electrode 32 Power Device 33 Second Temperature Sensor 34 Temperature Control Unit 46 Organic Layer 40 Organic EL Display Panel 43 Transparent Electrode 45 Striped Metal Electrode 51 External Motor 52 Feed Screw 60 Laser Light Beam Irradiation Device

Claims (27)

Vaporized vapor deposition material is supplied to a nozzle, and the vapor deposition material held in the nozzle is vaporized by heating the nozzle due to a temperature drop, and a thin film of the vapor deposition material is formed on a substrate disposed opposite to the nozzle opening. The vapor deposition method characterized by the above-mentioned. The deposition method according to claim 1, wherein cooling is promoted by connecting the nozzle to a heat conductor. The vapor deposition method according to claim 2, wherein the nozzle and the supply side of the vaporized vapor deposition material are connected by a heat insulator. The vapor deposition method according to claim 1, wherein the nozzle is heated by supplying power to an electrode connected to a heating element in contact with the nozzle. The vapor deposition method according to claim 1, wherein the nozzle is heated by irradiating the nozzle with a laser beam. The vapor deposition method according to claim 1, wherein a plurality of the nozzles are provided and the temperature is individually adjusted for each of the nozzles. The vapor deposition method according to claim 6, wherein the nozzle is selectively heated. The vapor deposition method according to claim 1, wherein the nozzle and the substrate are translated relatively and intermittently. A nozzle having an opening for holding the vapor deposition material and discharging the vaporized vapor deposition material, a temperature controller for heating and cooling the nozzle, and a feeder for supplying the vaporized vapor deposition material in communication with the nozzle to the nozzle And a vapor deposition head characterized by comprising: The vapor deposition head according to claim 9, further comprising a thermal conductor connected to the nozzle. The vapor deposition head according to claim 10, wherein a heat insulator is provided between the nozzle and the feeder. The vapor deposition head according to claim 9, wherein the temperature controller includes a heating element in contact with the nozzle and an electrode connected to the heating element and supplied with electric power. The vapor deposition head according to claim 9, wherein the temperature controller includes a light receiving unit that receives a laser beam in contact with the nozzle. The vapor deposition head according to claim 9, wherein a plurality of the nozzles are provided, and the temperature controller individually heats the nozzles. The vapor deposition head according to claim 14, wherein the temperature controller is connected to a control device that selects the nozzle to be heated. The vapor deposition head according to claim 9, wherein the vapor deposition head is connected to a drive device that translates the nozzle and the substrate relatively and intermittently. An apparatus for manufacturing an organic EL display panel, in which a plurality of organic EL elements each composed of at least one organic layer including a light emitting layer sandwiched between a pair of electrodes are arranged on a substrate,
A plurality of nozzles having openings for holding the vapor deposition material of the organic EL element and discharging the vaporized vapor deposition material; a temperature controller for heating and cooling the nozzle; and the vapor deposition material vaporized in communication with the nozzle. A vapor deposition head having a feeder for supplying to the nozzle;
An organic EL display panel manufacturing apparatus, comprising: a support mechanism that supports the vapor deposition head so that the opening of the nozzle faces the substrate apart from the substrate. The apparatus for manufacturing an organic EL display panel according to claim 17, wherein the vapor deposition head includes a heat conductor that is fixed to the nozzle and promotes cooling. The apparatus for manufacturing an organic EL display panel according to claim 18, wherein the vapor deposition head includes a heat insulator provided between the heat conductor and the supplier. The organic EL display panel according to any one of claims 17 to 19, wherein the temperature controller includes a heating element in contact with the nozzle and an electrode connected to the heating element and supplied with electric power. Manufacturing equipment. 21. The organic EL display panel manufacturing apparatus according to claim 17, wherein the temperature controller individually heats the nozzles by the heating element. The apparatus for manufacturing an organic EL display panel according to claim 21, further comprising a control device that is connected to the temperature controller and selects the nozzle to be heated. The apparatus for manufacturing an organic EL display panel according to any one of claims 17 to 21, further comprising: a driving device connected to the vapor deposition head and moving the nozzle and the substrate relatively and intermittently. . The apparatus for manufacturing an organic EL display panel according to any one of claims 17 to 23, wherein a plurality of sets of the nozzle and the heating element are arranged one-dimensionally. 24. The organic EL display panel manufacturing apparatus according to claim 17, wherein a plurality of sets of the nozzle and the heating element are two-dimensionally arranged. The temperature controller is connected to the nozzle or the heating element and detects a temperature, and is connected to the temperature detection unit and controls the temperature of the nozzle or the heating element according to the detected temperature. An apparatus for manufacturing an organic EL display panel according to any one of claims 17 to 25, comprising: a unit. 27. The apparatus for manufacturing an organic EL display panel according to claim 17, wherein the vapor deposition head is disposed below the substrate in the direction of gravity.

Images