JP2005228558A - Display body manufacturing method, display body, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a manufacturing method or the like of a display unit which can be made easily at a low cost, and a display unit obtained by it, and an electronic equipment using that display unit. <P>SOLUTION: This is the manufacturing method of a display unit which comprises a process of forming a lyophilic bank 3 surrounding the position to become a dot and a liquid repellent cathode separator 5 for dividing the dots on the bank 3, a process in which the liquid containing a material to become an organic EL element 4 is stored, then fixed and formed in the position to make dots, and a process of forming an individual electrode 6 for supplying charges to the organic EL element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for effectively forming a light emitting element or the like for each dot of a pixel constituting a display portion of a display body. Particularly, it is suitable for a display body manufactured by forming a cathode separator to separate each dot when forming an element or the like, an electronic device using the display body, and the like.

  In recent years, with the diversification and space saving of information equipment, there is an increasing need for a flat panel display device that consumes less power and has a smaller space area than a CRT. Examples of such flat display devices include liquid crystal displays and plasma displays. Recently, however, organic EL (electroluminescence) that is self-luminous, has high visibility, has high response speed, and can be driven by low-voltage direct current. There is an increasing expectation for display devices using elements.

  Among the display devices, a display body serving as a display portion is provided with a drive control element (active element) such as a thin film transistor (hereinafter referred to as “TFT”), an individual electrode, and an organic EL element in accordance with each dot. A conductive film serving as an electrode common to dots is sequentially disposed between the two substrates. Here, there is a display body having a so-called bottom emission structure in which the drive control element side is the display surface, but the aperture area is narrow (the aperture ratio is low), and the transmittance is reduced. In order to solve this problem, a display body having a so-called top emission structure in which the conductive film side is the display surface has been proposed (for example, see Patent Document 1).

  Further, as a method for manufacturing a display body having a top emission structure, a substrate on which a conductive film, an organic EL element and an individual electrode are formed and a substrate on which a drive control element is formed are manufactured, and the two substrates are bonded to each other. There has also been proposed a method for manufacturing (see, for example, Patent Document 2).

JP 2002-343579 A International Publication No. 03-53109 Pamphlet

In the above-described manufacturing method of the display body, a bank is formed that serves as a weir for fixing a light emitting material to be an organic electroluminescent element at a predetermined position of each dot. Here, the bank wettability (lyophilicity) may vary during the bank formation and in the steps after the bank formation. When the wettability is deteriorated, the adhesion between the organic EL element formed as a layer in the portion surrounded by the bank and the bank is deteriorated, and the element layer is thinly formed in the portion close to the bank. For this reason, a short circuit occurs between the individual electrode and the conductive film, which may affect the light emission characteristics. In order to prevent such a short circuit, a lyophilic insulating film (such as SiO ₂ ) is formed between the conductive film and the bank. However, the formation of the insulating film lowers the aperture ratio. Further, the number of processes increases for forming the insulating film, and the cost increases.

  Therefore, the present invention solves the above problems, and improves the lyophilicity of the bank without forming an insulating film, prevents a short circuit, and improves the light emission characteristics. The purpose is to obtain. Moreover, it aims at obtaining the electronic device using the display body obtained by that, and a display body.

The display body manufacturing method according to the present invention includes a lyophilic bank surrounding a position to be a dot on a substrate on which dots constituting the display body are formed, and a liquid repellent partition for partitioning the dots on the bank. A step of forming, a step of forming a light emitting element composed of the functional film by fixing a liquid containing a material that becomes a functional film at a position to be a dot, and a separate electrode for supplying a charge to the light emitting element And a process of performing.
In this embodiment, when a lyophilic bank surrounding a dot position and a liquid-repellent partition wall for partitioning the dots are formed on the bank, and a liquid containing a material to be a functional film is applied. In addition, the liquid for each dot is improved and the liquid is attached to the bank. Therefore, it is possible to prevent a short circuit between the electrodes sandwiching the functional film, and to improve the light emission characteristics. In addition, since an insulating film for preventing a short circuit is not provided, a decrease in the aperture ratio can be prevented, and the process and cost can be reduced.

Moreover, the display body manufacturing method which concerns on this invention forms a bank with a lyophilic material.
In the present invention, by forming the bank with a lyophilic material, the liquid can be attached to the bank without any special processing steps. Therefore, the process and cost can be further reduced.

Moreover, the display body manufacturing method which concerns on this invention forms a partition with a liquid repellent material.
In the present invention, the partition wall is formed of a liquid repellent material, so that the liquid can be cut easily without performing a special processing step. Therefore, the process and cost can be further reduced.

In the display body manufacturing method according to the present invention, after the bank and the partition are formed, the bank is subjected to a lyophilic process, and the partition is subjected to a liquid repellent process.
In the present invention, the bank is lyophilic and the partition is lyophobic, so that the bank is more lyophilic, the partition is lyophobic, and the light emission characteristics are more reliably improved. Can be planned.

The display body manufacturing method according to the present invention further includes a step of forming a film to be a common electrode on the substrate before forming the bank.
In the present invention, a film to be a common electrode is formed, so that the light emitting element is electrified and supplied together with the electrodes facing each other with the light emitting element interposed therebetween. The lyophilic bank formed at that time can improve the attachment of the light emitting element to the bank and can achieve a short circuit between the electrodes.

In addition, in the display body manufacturing method according to the present invention, a liquid containing a material to be a functional film is applied to the entire surface of the substrate, and the liquid is accumulated at positions where dots are formed.
In the present invention, by applying a liquid containing a material to be a functional film to the entire surface of the substrate, in the manufacturing process, the liquid can be cut for each dot in the partition wall, and the liquid can be attached to the bank. be able to.

Moreover, the display body manufacturing method which concerns on this invention stores the liquid containing the material used as a functional film in the position used as the selected dot.
In the present invention, the liquid containing the material for the functional film is stored in the portion where the selected dot is to be formed, so that the liquid for each dot in the partition is improved and stored in the bank. It is possible to exhibit the characteristics of

Moreover, the display body manufacturing method which concerns on this invention vapor-deposits the material used as an electrode, and forms an individual electrode.
In the present invention, the individual electrodes are formed by vapor deposition for each dot by the partition walls, so that the light emitting elements are electrified and supplied together with the electrodes facing each other with the light emitting elements interposed therebetween. By vapor deposition, the electrode can be formed without damaging the light emitting element and without affecting the light emitting characteristics of the light emitting element.

Moreover, the display body manufacturing method which concerns on this invention electrically connects the control element and individual electrode which control the electric charge supply to an individual electrode, after forming an individual electrode.
In the present invention, the display portion including the light emitting element and the control element are formed in separate steps in advance, and finally the display body is manufactured by electrical connection. Therefore, it is possible to effectively manufacture a display body using banks and partition walls, and to improve the light emission characteristics of the configured dots.

Further, the display body according to the present invention includes a light emitting element that constitutes each dot, a lyophilic bank surrounding each dot, a liquid repellent partition that partitions the dots on the bank, and charges the light emitting element. And an individual electrode to be supplied.
In the present invention, the lyophilic bank and the liquid repellent partition prevent a short circuit between the electrodes sandwiching the light emitting element, and improve the light emission characteristics without forming dots that cannot be displayed. I can. In addition, since an insulating film for preventing a short circuit is not provided, a decrease in the aperture ratio can be prevented, and the process and cost can be reduced.

In addition, an electronic apparatus according to the present invention includes the above display body and performs a display function.
In the present invention, since the display of the electronic device is made to display with the above-described display body, it is possible to display with good light emission characteristics without forming dots that cannot be controlled.

Embodiment 1 FIG.
FIG. 1 is a view showing a part of a display body according to the first embodiment of the present invention. FIG. 1 shows one dot. In this display body, a display portion having a display surface on which display is actually performed and a portion having an element for controlling charge supply to each dot in order to display the display portion are formed and bonded together. It is the display body using the organic EL element 4 manufactured by the method to do. In this embodiment, it is assumed that the display body is configured by arranging dots in a matrix in the two-dimensional direction. Further, there are a passive matrix method and an active matrix method as a method for controlling charge supply. Here, an active matrix method display body will be described in particular. However, it is not limited to this.

  In FIG. 1, a conductive film 2 is entirely formed on a glass substrate 1 having a display surface on a surface opposite to a surface to be a display surface. The conductive film 2 serves as a common electrode for each dot. Since it is provided on the display surface side, a conductive material such as ITO, IZO, GZO, or ICO that is transparent in the visible light region is used. In the present embodiment, the conductive film 2 is made of ITO and functions as an anode for supplying holes.

  A bank 3 is formed on the conductive film 2. The bank 3 is provided in order to form the organic EL element 4 to be a light emitter (dot) at a predetermined position. In particular, in the case of using a droplet discharge method in which the organic EL element 4 is formed by fixing the light emitting material after discharging the liquid containing the light emitting material, it becomes a weir for storing the liquid containing the light emitting material. The bank 3 is made of an insulating material of an organic compound that can be formed by, for example, photolithography or the like, such as polyimide or acrylic. In this embodiment mode, lyophilicity (wetting property) with respect to a liquid containing a light-emitting material is assumed.

  A cathode separator 5 is provided on the bank 3. The cathode separator 5 mainly serves as a partition that cuts off the connection of the electrode material that is dry-formed, and plays a role for forming the individual electrode 6 for each dot. In order to effectively cut off this connection, it is formed in an inverted taper shape with an overhang (a side opposite to the bank 3 is wide and the cross section is trapezoidal). In addition, in order to effectively store the liquid containing the light emitting material in each bank, it has liquid repellency with respect to the liquid containing the light emitting material.

  An organic EL element 4 serving as a light emitter is formed in a portion surrounded by the bank 3. In the present embodiment, the organic EL element 4 includes a hole injecting and transporting layer 4A made of, for example, a thiophene-based conductive polymer (PEDOT) and a light emitting layer 4B of a light emitting polymer (LEP). However, the material of each layer is not limited to these. The light emitting layer 4 </ b> B emits light by receiving electric charges from the conductive film 2 and the individual electrode 6. The luminance of light emission is adjusted by the supply amount of electric charges (electrons in the present embodiment) from the individual electrodes 6. In addition, regarding the configuration of the organic EL element 4, an electron injecting and transporting layer may be formed between the light emitting layer 4 </ b> B and the individual electrode 6 in some cases. Furthermore, when the hole (electron) injection layer is distinguished from the transport layer, or it is composed of three layers of an electron injection layer, a hole injection layer, and a light emitting layer, or the organic EL element 4 is formed with a different configuration There is also. The conductive film 2 may function as a hole injection layer, and the thiophene-based conductive polymer may function as a hole transport layer. Each of these layers is sometimes called a functional film.

  In the present embodiment, the individual electrode 6 is made of a conductive metal material such as Al, but is made of a conductive material that can be formed by a dry film formation method such as a vapor deposition method or a sputtering method. If there is, it is not restricted to a metal material in particular.

  On the other hand, on the counter substrate 9, a drive control element 7 such as a TFT is formed for each dot. Then, light emission control by a so-called active matrix method is performed. Each drive control element 7 controls the amount of charge supplied to the organic EL element 4 of each dot. In the present embodiment, the production of the drive control element 7 on the counter substrate 9 is performed in a process different from the production process of the conductive film 2, the organic EL element 4 and the like formed on the glass substrate 1. To do. Therefore, the produced glass substrate 1 and the counter substrate 9 are finally joined to manufacture a display body. At this time, the drive control element 7 and the individual electrode 6 are electrically connected by the conductive paste material 8. . In the present embodiment, it is assumed that the conductive paste material 8 is a material having anisotropic characteristics. Although the conductive paste material is used here, the present invention is not particularly limited to this. For example, the drive control element 7 and the individual electrode 6 may be electrically connected using a conductive film or the like. .

  FIG. 2 is a diagram illustrating a manufacturing process on the glass substrate 1 side. Next, the manufacturing process of the display body in the present embodiment will be described mainly for the manufacturing process on the glass substrate 1 side. A conductive material is formed on the entire surface of the glass substrate 1 opposite to the display surface by a dry film formation method such as vapor deposition or sputtering, and a conductive film 2 is formed (FIG. 2A).

After the conductive film 2 is formed, a film to be the bank 3 is formed on the entire surface (FIG. 2B). In this embodiment, photosensitive polysilazane is formed as a material for the bank 3, but a more lyophilic material may be used. Then, by using a photolithography method and an etching method, a portion to be enclosed is removed to form a bank 3 (FIG. 2C). Further, for example, lyophilic treatment such as O ₂ plasma treatment may be performed on the formed bank 3 to make it more lyophilic. Here, when the organic EL element 4 is formed, a liquid containing a light emitting material is applied over the entire surface or locally. However, since this liquid is basically aqueous, May be considered to be almost the same as hydrophilicity.

  Further, a cathode separator 5 is formed (FIG. 2D). If the cathode separator 5 is made lyophilic, problems such as poor separation of the liquid of each dot when applied over the entire surface, and failure to store the liquid only at a desired location (enclosed portion) occur. In the present embodiment, an acrylic resin is formed as a material for the cathode separator 5, but a material having more liquid repellency may be used. Further, after the formation, a liquid repellent treatment such as fluorine (F) plasma treatment may be performed. The cathode separator 5 is also formed using a photolithography method and an etching method.

  After the cathode separator 5 is formed, the organic EL element 4 is formed (FIG. 2 (e)). First, the hole transport injection layer 4A is formed. Since the hole transport injection layer 4B becomes a light emitting material common to dots, the entire surface such as coating with slits, caps, etc. can be applied.

  On the other hand, in the case of manufacturing a monochrome display body, the entire surface of the light emitting layer 4B can be applied in the same manner as the hole transport injection layer 4A. When two or more types of light-emitting layers 4B are formed to emit light, it is difficult to form and apply a liquid containing each light-emitting material on the entire surface. A method of performing local application such as the above-described method is used. You may perform local application | coating also to the positive hole transport injection layer 4B mentioned above.

  Individual electrodes 6 are formed on each dot (FIG. 2 (f)). In the present embodiment, the individual electrode 6 is formed by evaporating an electrode material. The evaporated electrode material is separated by the cathode separator 5 and deposited on the organic EL element 4 of each dot. The individual electrode 6 is formed and the production on the glass substrate 1 side is completed.

  Next, an example of a manufacturing method on the counter substrate 9 side will be described. Although a manufacturing method on the counter substrate 9 side is not described in detail here, various manufacturing methods have been conventionally shown. Therefore, the manufacturing method is not limited to this method. In the present embodiment, the material for forming the counter substrate 9 and the drive control element 7 does not need to be made of a particularly transmissive material, so various materials such as durability can be used depending on the application. The desired material can be selected from a wide range.

  First, a film (for example, silicon) for forming the drive control element 7 is formed on the entire surface of the counter substrate 9 by sputtering or the like. In some cases, the film may be polycrystallized. Then, after patterning using a photolithography method, unnecessary portions are removed using an etching method to form a semiconductor thin film (not shown). After forming a gate insulating film and a gate electrode (both not shown) in alignment with dots, the semiconductor thin film is doped with impurities to form regions such as a source and a drain. Then, a wiring layer, an insulating layer, and a dot electrode layer (not shown) are stacked by metal film formation, patterning by photolithography, and etching, and the drive control element 7 is formed for each dot.

  And the produced glass substrate 1 and the counter substrate 9 are joined. When joining the two substrates, it is necessary to perform alignment accurately so that the individual electrode 6 and the dot electrode layer (not shown) of the drive control element 7 are electrically connected to each dot. . In order to ensure the electrical connection, the conductive paste material 8 is used for pressure bonding. After bonding the two substrates in this manner, for example, in order to prevent oxidation or the like, sealing is performed by filling with an inert gas after bonding. A display body is manufactured through the above steps.

As described above, according to the first embodiment, the bank 3 is formed of a lyophilic material or lyophilic treatment such as O ₂ plasma treatment is performed, and the cathode separator 5 is formed of a lyophobic material or fluorine-based. Since it is formed by performing a liquid repellent treatment such as a plasma treatment, the organic EL element 4 is easily attached in the vicinity of the bank 3 without providing an insulating film, and a short circuit between the conductive film 2 and the individual electrode 6 is prevented. Luminous properties can be improved. In addition, since an insulating film is not provided, a decrease in the aperture ratio can be prevented, and the process and cost can be reduced. Further, it is possible to improve the liquid cut for each dot when the organic EL element 4 is formed by the cathode separator 5.

Embodiment 2. FIG.
In the above-described embodiment, the light emitter is composed of the organic EL element 4, but the present invention is not limited to this. For example, the present invention can also be applied when other light-emitting elements such as an inorganic EL element are used.

Embodiment 3 FIG.
FIG. 3 is a diagram illustrating an electronic apparatus using a display body manufactured according to the present invention. 3A shows a PDA (Personal Digital Assistant), FIG. 3B shows a mobile phone, and FIG. 3C shows a digital camera. Although not shown in this embodiment mode, a display body manufactured according to the present invention can be used for an electronic device that uses a display body to achieve a display function, such as a computer or a game machine.

It is a figure showing a part of display body concerning a 1st embodiment of the present invention. It is a figure showing the preparation process by the side of the glass substrate. It is a figure showing the electronic device using the display body produced by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate, 2 Conductive film, 3 Bank, 4 Organic EL element, 4A Hole injection transport layer, 4B Light emitting layer, 5 Cathode separator, 6 Individual electrode, 7 Drive control element, 8 Conductive paste material, 9 Opposite substrate.

Claims (11)

Forming a lyophilic bank surrounding a position to be the dot on a substrate on which dots constituting the display body are formed, and a liquid-repellent partition wall for partitioning the dots on the bank;
A step of fixing a liquid containing a material to be a functional film at a position to be the dot and fixing the liquid, and forming a light emitting element constituted by the functional film;
Forming a separate electrode for supplying an electric charge to the light emitting element.   The display body manufacturing method according to claim 1, wherein the bank is formed of a lyophilic material.   The display body manufacturing method according to claim 1, wherein the partition walls are formed of a liquid repellent material.   The display body manufacturing method according to claim 1, wherein after forming the bank and the partition, the bank is subjected to a lyophilic process, and the partition is subjected to a liquid repellent process.   The display body manufacturing method according to claim 1, further comprising a step of forming a film to be a common electrode on the substrate before forming the bank.   The display body manufacturing method according to claim 1, wherein a liquid containing a material to be a functional film is applied to the entire surface of the substrate, and the liquid is accumulated at a position to be the dot.   The display body manufacturing method according to claim 1, wherein a liquid containing a material to be a functional film is accumulated at the position to be the selected dot.   The display body manufacturing method according to claim 1, wherein the individual electrode is formed by vapor-depositing a material to be an electrode. After forming the individual electrodes,
The display element manufacturing method according to claim 1, wherein a control element that controls charge supply to the individual electrode is electrically connected to the individual electrode. A light emitting element constituting each dot;
A lyophilic bank surrounding each dot;
A liquid-repellent partition wall separating the dots on the bank;
A display body comprising an individual electrode for supplying electric charges to the light emitting element. An electronic apparatus comprising the display body according to claim 10 and having a display function.

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