JP2004186044A - Organic el display panel, getter part forming method of organic el display panel and forming device of getter part of organic el display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing technology of a getter part superior in points such as workability, productivity, and reliability, and contribute to providing an inexpensive organic EL display having high performance. <P>SOLUTION: The getter part 3 to absorb or adsorb moisture in a package 2 composed of a fixed side substrate 21 to which the EL element part 1 is fixed and a non-fixed side substrate 22 to which the EL element part 1 is not fixed is formed on the surface of the non-fixed side substrate 22. The non-fixed side substrate 22 is arranged in a treatment chamber 4 provided with an exhaust system 41, and a porous film is formed as the getter part 3 by vacuum vapor deposition on the surface of the non-fixed side substrate 22. Two evaporation sources 51, 52 are installed, and one is a material to absorb or adsorb the moisture, and another one is a material to absorb or adsorb oxygen. So that evaporated material from the evaporation sources 51, 52 are incident from different directions into the non-fixed side substrate 22, a direction changing means 7 changes the direction of the non-fixed side substrate 22 against the evaporation sources 51, 52. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention of the present application relates to an organic EL display that has recently been promising as a flat panel display (FPD).
[0002]
[Prior art]
The organic EL display is a display using an organic EL element. The organic EL element has a structure in which an organic thin film is sandwiched between a pair of electrodes, and at least one of them is a transparent electrode such as indium-tin oxide (ITO) for convenience of extracting light. A DC voltage is applied to the pair of electrodes, and electrons are injected from one side and holes are injected from the other side into the organic thin film. These carriers recombine and excite in the organic thin film, and when this returns to the ground state, light emission occurs.
[0003]
Since an organic EL display emits light by itself, a backlight such as a liquid crystal display is unnecessary. In addition, it is excellent in high-speed response, and it is easy to reduce the thickness and drive voltage. Also, the manufacturing process is simpler than a liquid crystal display or the like. For these reasons, it is drawing attention as a next-generation display technology, and practical application to mobile phones and the like has already begun.
[0004]
The structure of the current organic EL display panel will be described with reference to FIG. FIG. 5 is a schematic sectional view of a current organic EL display panel. The organic EL display panel shown in FIG. 5 includes an EL element portion 1 including a pair of electrodes 11 and 12 and an organic thin film 13 sandwiched between the pair of electrodes 11 and 12, and a package 2 containing the EL element portion 1 therein. Consisting of Note that the organic EL display panel refers to an organic EL display that includes a package 2 excluding a drive circuit and the like and components inside the package.
[0005]
For convenience of extracting light, at least one of the pair of electrodes 11 and 12 is a transparent electrode such as ITO. In the case of an active type in which each pixel is driven, a thin film transistor is formed as one electrode. The package 2 includes a fixed substrate 21 to which the EL element 1 is fixed, and a non-fixed substrate 22 to which the EL element 1 is not fixed. The current organic EL display is a so-called bottom emission type, and the example shown in FIG. 5 also belongs to this. That is, the fixed-side substrate 21 is made of glass and transparent. Light from the EL element section 1 passes through the fixed substrate 21 and is emitted. That is, the fixed-side substrate 21 is located on the side of the viewer of the image.
[0006]
As already pointed out, the organic luminescent material used for the organic EL display is susceptible to moisture and rapidly deteriorates its properties due to moisture absorption. For this reason, a hygroscopic material (drying agent) is sealed in the package 2. The hygroscopic material has a sheet shape, and is fixed to the surface of the non-fixed-side substrate 22 with an adhesive.
[0007]
[Problems to be solved by the invention]
Although providing a moisture absorbing material in a package is unavoidable due to the properties of the organic thin film, the conventional method of attaching a sheet-like material has problems in workability, productivity, reliability, and the like. That is, the sticking operation is troublesome and troublesome, and the productivity cannot be increased. Also, depending on the properties of the adhesive, the hygroscopic material may be peeled off by heat or the like at the time of light emission.
[0008]
The invention of the present application has been made in order to solve such a problem, and provides a technique for fixing a getter portion which is excellent in workability, productivity, reliability, and the like. It has technical significance that contributes to the provision.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present application provides an organic thin film by applying a voltage to the organic thin film with the pair of electrodes sandwiching the organic thin film at least one of which is a transparent electrode. An organic EL display panel,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element portion is fixed, and a non-fixed substrate on which the EL element is not fixed,
The package is provided with a getter unit that absorbs or adsorbs moisture, and the getter unit is configured to be a porous film formed by vacuum deposition on the surface of the fixed substrate or the non-fixed substrate. .
According to a second aspect of the present invention, in order to solve the above problem, in the configuration of the first aspect, the getter portion is made of a material that absorbs or adsorbs oxygen in addition to a material that absorbs or adsorbs moisture. It has the structure of.
In order to solve the above-mentioned problem, the invention according to claim 3 is characterized in that, in the structure of claim 1 or 2, the getter section is formed by causing evaporated matter from different directions to enter from different directions. It has a configuration consisting of the above layers.
According to another aspect of the present invention, there is provided a method of manufacturing an organic EL display panel including an EL element portion therein.
A getter section forming step of forming a getter section for absorbing or adsorbing moisture in the package on the surface of the fixed-side substrate or the non-fixed-side substrate,
The getter section forming step has a configuration in which a porous film is formed as a getter section by vacuum evaporation on the surface of the fixed-side substrate or the non-fixed-side substrate.
According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the getter portion forming step includes a material that absorbs or adsorbs oxygen in addition to the material that absorbs or adsorbs moisture. Is formed to form a getter portion made of
According to a sixth aspect of the present invention, in the configuration of the fourth or fifth aspect, in the getter portion forming step, two or more evaporates from different directions are made to enter from different directions. Is formed to form a getter portion composed of the above layers.
According to another aspect of the present invention, there is provided an organic EL display panel in which an EL element portion is housed inside a package including a fixed substrate and a non-fixed substrate. Or a getter portion forming apparatus for forming a getter portion to be adsorbed on the surface of the fixed side substrate or the non-fixed side substrate,
A processing chamber having a fixed-side substrate or a non-fixed-side substrate disposed therein and having an exhaust system,
Consisting of an evaporation source provided in the processing chamber,
It has a configuration in which a porous film is formed as a getter portion by vacuum evaporation on the surface of the fixed-side substrate or the non-fixed-side substrate.
According to an eighth aspect of the present invention, in order to solve the above problem, in the configuration of the seventh aspect, at least two evaporation sources are provided, and one of the evaporation sources is provided for evaporating a material that absorbs or adsorbs moisture. Source and the other is a source of evaporation of the material that absorbs or adsorbs oxygen.
According to a ninth aspect of the present invention, in order to solve the above problem, in the configuration of the seventh or eighth aspect, the evaporated matter from the evaporation source enters the fixed-side substrate or the non-fixed-side substrate from different directions. Direction changing means for relatively changing the direction of the fixed-side substrate or the non-fixed-side substrate with respect to the evaporation source is provided, and the direction is changed so that a porous film is formed by irradiating the evaporant from different directions. It has a configuration in which a control unit for controlling the means is provided.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter, embodiments) will be described.
First, an embodiment of the invention of an organic EL display panel will be described. FIG. 1 is a schematic sectional view of the organic EL display panel of the present invention. The organic EL display panel shown in FIG. 1 is a so-called top emission type. The top emission type is a type in which light is emitted from the end of the EL element portion 1, and the light is emitted through the non-fixed substrate 22.
[0011]
The bottom-emission type organic EL display panel as shown in FIG. 5 emits light through the fixed substrate 21 of the package 2 and thus has a problem that light utilization efficiency is poor. That is, a circuit for driving the EL element unit 1 is formed on the fixed substrate 21, and has a lower light transmittance than an ordinary simple transparent body. On the other hand, in the top emission type as shown in FIG. 1, light from each EL element section 1 is emitted through the non-fixed side substrate 22 as it is. Since the non-fixed side substrate 22 does not fix the EL element section 1, it can be made a simple transparent body and can have a high transmittance. Therefore, the light use efficiency is higher than that of the bottom emission type.
[0012]
The fixed-side substrate 21 and the non-fixed-side substrate 22 are formed of a transparent glass plate. A so-called blue plate, white plate, soda lime glass, borosilicate glass, or the like is considered as a base material of the fixed substrate 21 and the non-fixed substrate 22. The non-fixed-side substrate 22 has a concave portion as shown in FIG. 1, and this concave portion can be formed by wet etching using a hydrofluoric acid-based etchant.
[0013]
In the present embodiment, a three-color independent organic EL display panel is provided. That is, each EL element unit 1 fixed to the fixed-side substrate is divided into R emission, G emission, and B emission. The pair of electrodes 11, 12 and the organic thin film 13 constituting each EL element portion 1 can be formed by a method similar to the conventional method.
[0014]
In the organic EL display panel of the present embodiment, a getter unit 3 is provided in a package 2. The “getter portion” is a term having a broader meaning than the hygroscopic material, and is used in this specification to mean a member that absorbs or adsorbs a material that degrades the organic thin film 13 such as moisture or oxygen. According to the study of the present inventor, it has been found that the organic thin film 13 may be deteriorated not only by moisture but also by oxygen. Therefore, in some cases, it is necessary to provide a member for absorbing or adsorbing oxygen in the package.
[0015]
In the present embodiment, the getter unit 3 is fixed to the non-fixed substrate 22. FIG. 2 is a schematic plan view of the non-fixed substrate 22 shown in FIG. As shown in FIG. 2, the getter unit 3 is arranged along the periphery of the non-fixed-side substrate 22 and inside the periphery. The disposition shape of the getter portion 3 is a circumferential shape having a rectangular outline. And it is arranged inside the arrangement shape of the getter unit 3. The intermediate rib 23 is formed on the non-fixed substrate 22 so as to separate the getter area from the light emitting area.
[0016]
A major feature of the organic EL display panel of the present embodiment is that the getter section 3 is a porous film formed on the surface of the fixed-side substrate 21 by vacuum evaporation. Hereinafter, this point will be described with reference to FIG. 3 while also describing the embodiments of the method invention and the apparatus invention. FIG. 3 is a schematic front sectional view of a getter section forming apparatus used in the method of forming the getter section 3 shown in FIG.
[0017]
The apparatus shown in FIG. 3 includes a processing chamber 4 having a non-fixed substrate 22 disposed therein and an exhaust system 41, and evaporation sources 51 and 52 provided in the processing chamber 4. The processing chamber 4 is an airtight vacuum vessel provided with a gate valve (not shown). The exhaust system 41 is configured to exhaust the inside of the processing chamber 4 to a predetermined vacuum pressure.
[0018]
In the present embodiment, the getter unit 3 is formed of a material that absorbs or adsorbs moisture (hygroscopic material) and a material that absorbs or adsorbs oxygen (hereinafter, not a general expression, is referred to as an acid absorbent). ing. Therefore, a first evaporation source 51 for a moisture absorbing material and a second evaporation source 52 for an acid absorbing material are provided in the processing chamber 4. Each of the evaporation sources 51 and 52 comprises crucibles 511 and 521 and heating means 512 and 522 for heating and evaporating the material in the crucibles 511 and 521. As the hygroscopic material, for example, silica gel or zeolite is used. As the acid absorbing material, for example, a mixture of ferrous oxide, ferric oxide, and iron hydroxide in a predetermined ratio is used. Therefore, the first and second evaporation sources 51 and 52 are configured to evaporate these materials. The heating means 512 and 522 provided in the evaporation sources 51 and 52 are drawn as a resistance heating type, but may be an electron beam heating type or an induction heating type. Each of the evaporation sources 51 and 52 has a shutter or the like (not shown) if necessary.
[0019]
As shown in FIG. 3, a holder 6 that holds the non-fixed-side substrate 22 at a predetermined position and a predetermined posture is provided in the processing chamber 4. The holder 6 holds the non-fixed-side substrate 22 obliquely above the evaporation sources 51 and 52. The non-fixed-side substrate 22 is held with the surface on which the getter section 3 is formed (hereinafter, the film forming surface) facing downward.
The holder 6 is configured to hold the non-fixed-side substrate 22 so that the film formation surface of the non-fixed-side substrate 22 is oblique to the flight direction of the evaporant. That is, a line connecting the centers of the opening surfaces of the crucibles 511 and 521 and the center of the film forming surface of the non-fixed substrate 22 is not perpendicular to the film forming surface but has an angle θ (hereinafter, holding angle). ing.
The holder 6 simultaneously holds the two non-fixed substrates 22 with the central axis of the processing chamber 4 interposed therebetween. The holding angle θ of each non-fixed side substrate 22 is the same. The two crucibles 511 and 521 are provided at positions near the central axis of the processing chamber 4 with the processing chamber 4 interposed therebetween.
[0020]
In the apparatus of the present embodiment, the orientation of the non-fixed substrate 22 with respect to each of the evaporation sources 51 and 52 is relatively changed such that the evaporant from each of the evaporation sources 51 and 52 enters the non-fixed substrate 22 from different directions. And a control unit 8 for controlling the direction changing means 7. In the present embodiment, the direction changing unit 7 includes a spindle 71 holding the holder 6 and a rotation drive source 72 that rotates the holder 6 via the spindle 71. The control unit 8 controls the sequence of the rotary drive source 72 and the two evaporation sources 51 and 52.
[0021]
The holder 6 is held by a spindle 71 extending upward. The spindle 71 penetrates the upper plate portion of the processing chamber 4 in an airtight and rotatable manner. A rotation drive source 72 is connected to the spindle 71, and the holder 6 rotates via the spindle 71. Note that the rotation axis coincides with the central axis of the processing chamber 4.
[0022]
The operation of the device shown in FIG. 3 will be described below. For convenience of description, the two non-fixed-side substrates 22 are referred to as a first non-fixed-side substrate 22A and a second non-fixed-side substrate 22B. First, as shown in FIG. 3, the control unit 8 operates the rotation drive source 72 to move the first non-fixed substrate 22A to the first evaporation source 51 side and the second non-fixed substrate 22B to the second non-fixed substrate 22B. It is located on the side of the second evaporation source 52. In this state, the control unit 8 operates the evaporation sources 51 and 52 to perform film formation by vacuum evaporation. Evaporated matter flying from the first and second evaporation sources 51 and 52 adheres to the film-forming surfaces of the first and second non-fixed-side substrates 22A and 22B, and evaporation is performed. At this time, the evaporated matter from the first evaporation sources 51 and 52 and the evaporated matter from the second evaporation sources 51 and 52 are mixed on each film forming surface. That is, the vapor deposition is performed while the moisture absorbing material and the acid absorbing material are mixed.
[0023]
After performing the vapor deposition for a predetermined time, the control unit 8 operates the rotation drive source 72 to rotate the holder 6 by 180 degrees. As a result, the second non-fixed substrate 22B is located on the first evaporation source 51 side, and the first non-fixed substrate 22A is located on the second evaporation source 52 side. In this state, vacuum deposition is performed similarly. Evaporates from the first and second evaporation sources 51 and 52 are attached to each film-forming surface while being mixed. After performing the vapor deposition for the same time, the control unit 8 operates the rotation drive source 72 again to rotate the holder 6 by 180 degrees. In this state, vacuum deposition is performed in the same manner. In this manner, the vacuum deposition on each film forming surface is repeated while rotating the holder 6 by 180 degrees.
When the process is repeated to the extent that the entire thickness becomes necessary for the getter portion 3, the process is completed. After the inside of the processing chamber 4 is evacuated, venting is performed as necessary, and a transport unit (not shown) takes out the first and second non-fixed-side substrates 22A and 22B from the processing chamber 4.
[0024]
According to such an apparatus and method, the getter unit 3 capable of efficiently collecting moisture and oxygen is suitably formed. Hereinafter, this point will be described with reference to FIG. FIG. 4 is a diagram schematically showing formation of the getter unit 3 by the apparatus shown in FIG. The arrows in FIG. 4 indicate the direction of incidence of the evaporant.
As is well known, when a film is formed on a certain surface 220, the particles migrate on the surface, and eventually grow into a thin film while locally forming a mass 30 having a certain size. At this time, as shown in FIG. 4A, when the evaporant is obliquely incident on the film formation surface 220, the lump 30 is also inclined in the incident direction. As the evaporant continues to be incident, each lump 30 becomes larger and connected, and eventually becomes a state of completely covering the film formation surface 220.
[0025]
Here, as shown in FIG. 4 (2), if the incident direction of the evaporant is changed before the respective blocks 30 are connected to completely cover the film forming surface 220, the incident direction after the change is changed. An inclined new mass 30 is formed, or the growth direction of the mass 30 changes to the changed incident direction. Then, as shown in FIG. 4C, when the incident direction of the evaporant is further changed, the inclination direction of the lump 30 is further changed.
[0026]
When the film is grown while changing the incident direction of the evaporant, small openings and cavities are randomly formed in the film, and a porous film is formed. The getter section 3 in the present embodiment is also porous formed by such a method. Since the getter section 3 made of such a porous film has a large surface area and a complicated internal structure, it has a high function of absorbing or adsorbing moisture or oxygen. In order to form a sufficiently porous getter portion 3, it is desirable to change the incident direction 5 to 10 times or more in one formation of the getter portion 3. Incidentally, the entire thickness of the getter portion 3 may be about 500 Å to 1000 Å.
[0027]
The positions of the first and second non-fixed-side substrates 22A and 22B may be 90 degrees away from the direction connecting the crucibles 511 and 521 in plan view. When the film is formed while being rotated by 180 degrees at this position, the first and second non-fixed-side substrates 22A and 22B are always equidistant from the two crucibles 511 and 521, so that a more uniform film is formed. Can be performed.
[0028]
According to the present embodiment, since the getter unit 3 is formed by the vacuum evaporation method, it is easy to automate, and the adhesion strength of the getter unit 3 can be easily increased sufficiently, and the adhesion strength due to heat or the like can be easily increased. There is no problem of decline. For this reason, it is superior in terms of workability, productivity, reliability, and the like, as compared with the related art. The getter unit 3 may be formed on the fixed-side substrate 21 in some cases. Also in this case, the method and apparatus of the present embodiment can be adopted.
The configuration of the organic EL display includes a structure in which three color EL element portions of RGB are individually formed, a structure in which each color of RGB is emitted by a combination of a blue EL device portion and a color conversion film, and a white EL device portion. And any combination of color filters.
[0029]
In the apparatus of the above embodiment, the first evaporation source 51 for the moisture absorbing material and the second evaporation source 52 for the acid absorbing material are provided in the same processing chamber 4, but may be provided in separate processing chambers. is there. In this case, a multilayer film is formed by alternately forming a film of the moisture absorbing material and a film of the acid absorbing material. Also in this case, the direction of incidence of the evaporant is alternately changed by the direction changing means to form a porous film.
In addition, the direction changing unit 7 described above changes the direction by rotating the holder 6, but another configuration is also possible. For example, the holder may be fixed and the two evaporation sources 51 and 52 may be rotated. In some cases, for the plate-like material, the getter portion 3 is formed by the above-described method and apparatus, and then cut to obtain individual non-fixed-side substrates 22.
[0030]
【The invention's effect】
As described above, according to the invention of claims 1, 4 and 7 of the present application, the getter portion is formed on the surface of the fixed-side substrate or the non-fixed-side substrate by vacuum deposition, so that workability, productivity, It is excellent in reliability and the like. In addition, since the getter portion is a porous film, the efficiency of absorbing or adsorbing moisture or oxygen is high, and a high-quality organic EL display panel is provided.
According to the second or fifth aspect of the present invention, in addition to the effects of the first, fourth or eighth aspect, the getter portion is made of a material that absorbs or adsorbs oxygen in addition to a material that absorbs or adsorbs moisture. Therefore, deterioration of the organic thin film is further suppressed. For this reason, a higher quality organic EL display panel is provided.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an organic EL display panel of the present invention.
FIG. 2 is a schematic plan view of the non-fixed substrate 22 shown in FIG.
3 is a schematic front sectional view of a getter section forming apparatus used in the method of forming the getter section 3 shown in FIG.
FIG. 4 is a view schematically showing formation of a getter section 3 by the apparatus shown in FIG.
FIG. 5 is a schematic sectional view of a current organic EL display panel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 EL element part 2 Package 21 Fixed side substrate 22 Non-fixed side substrate 3 Getter part 4 Processing chamber 51 Evaporation source 511 Crucible 512 Heating means 52 Evaporation source 521 Crucible 522 Heating means 6 Holder 7 Direction change means 71 Spindle 72 Rotation drive source 8 Control unit

Claims (9)

An organic EL display panel that emits an organic thin film by applying a voltage to the organic thin film with the pair of electrodes sandwiching the organic thin film with a pair of electrodes at least one of which is a transparent electrode,
An EL element portion comprising the organic thin film and the pair of electrodes;
A package in which the EL element is housed,
The package includes a fixed substrate on which the EL element portion is fixed, and a non-fixed substrate on which the EL element is not fixed,
The package is provided with a getter unit that absorbs or adsorbs moisture, and the getter unit is a porous film formed by vacuum deposition on the surface of the fixed substrate or the non-fixed substrate. Organic EL display panel. 2. The organic EL display panel according to claim 1, wherein the getter section is made of a material that absorbs or adsorbs oxygen in addition to a material that absorbs or adsorbs moisture. 3. The organic EL display panel according to claim 1, wherein the getter portion includes two or more layers formed by allowing evaporants from different directions to enter from different directions. 4. A method for manufacturing an organic EL display panel containing an EL element portion therein,
A getter section forming step of forming a getter section for absorbing or adsorbing moisture in the package on the surface of the fixed-side substrate or the non-fixed-side substrate,
The method for manufacturing an organic EL display panel, wherein the getter portion forming step is a step of forming a porous film as a getter portion on the surface of the fixed side substrate or the non-fixed side substrate by vacuum deposition. 5. The organic EL display panel according to claim 4, wherein the getter portion forming step forms a getter portion made of a material that absorbs or adsorbs oxygen in addition to a material that absorbs or adsorbs moisture. Production method. 6. The organic EL display according to claim 4, wherein in the getter section forming step, a getter section including two or more layers is formed by causing evaporants from different directions to enter from different directions. Panel manufacturing method. In an organic EL display panel in which an EL element portion is housed inside a package composed of a fixed-side substrate and a non-fixed-side substrate, a getter portion that absorbs or adsorbs moisture in the package is provided on the surface of the fixed-side substrate or the non-fixed-side substrate. A getter portion forming apparatus for forming
A processing chamber having a fixed-side substrate or a non-fixed-side substrate disposed therein and having an exhaust system,
An evaporation source provided in the processing chamber,
A getter portion forming apparatus for an organic EL display panel, wherein a porous film is formed as a getter portion on a surface of a fixed side substrate or a non-fixed side substrate by vacuum deposition. At least two evaporation sources are provided, one is an evaporation source for a material that absorbs or adsorbs moisture, and the other is an evaporation source for a material that absorbs or adsorbs oxygen. An apparatus for forming a getter portion of an organic EL display panel according to claim 7. Direction changing means for relatively changing the direction of the fixed-side substrate or the non-fixed-side substrate with respect to the evaporation source is provided such that the evaporant from the evaporation source enters the fixed-side substrate or the non-fixed-side substrate from different directions. 9. The organic EL display panel according to claim 7, further comprising a control unit configured to control the direction changing unit so that a porous film is formed by injecting an evaporant from different directions. Getter section forming device.

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