JP2006172761A - Process of manufacture of electro-optical device, and electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an electro-optical device and the electro-optical device wherein uniformity of the shape of a light emitting element is improved. <P>SOLUTION: Before minute liquid droplets composed of a positive hole layer forming liquid is ejected to an ejection face 20a, a space over the ejection face 20a is made under atmosphere of steam H, a region except the ejection face 20a is covered by a mask Mk2, an ultraviolet ray Luv is irradiated only on that ejection face 20a so that lyophilic property to the liquid of a photocatalyst to the minute liquid droplets is induced. Then, by the portion for the inducement of lyophilic property to the liquid of the photocatalyst, positive hole layer droplets to spread with wetting action over the entire face of the ejection face 20a are made to be formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an electro-optical device and an electro-optical device.

  Conventionally, an organic electroluminescence display (organic EL display) as an electro-optical device including an organic electroluminescence element (organic EL element) is known as a display including a light emitting element.

  In general, a manufacturing method of an organic EL element is roughly classified according to a constituent material of the organic EL layer. That is, when a low molecular organic material is used as a constituent material of the organic EL layer, a so-called gas phase process is used in which the low molecular organic material is deposited to form an organic EL layer. On the other hand, when a polymer organic material is used as a constituent material of the organic EL layer, a so-called liquid phase process is used in which a solution obtained by dissolving the polymer organic material in an organic solvent is applied and dried.

  In particular, the ink jet method in the liquid phase process discharges the solution as fine droplets (micro droplets), so that an organic EL layer is formed compared to other liquid phase processes (for example, spin coating). The position, film thickness, etc. can be controlled with higher accuracy. Moreover, since the ink jet method discharges the droplets only in the region (element formation region) where the organic EL layer is formed, the amount of the polymer organic material that is the raw material can be reduced.

  However, in such an ink jet method, the shape of the fine liquid droplets that have landed on the element formation region is reflected in the shape of the organic EL layer, and thus the fine liquid droplets that have landed are not flat (for example, a hemispherical convex shape). ) Causes a problem that the shape of the organic EL layer is not uniform.

Therefore, conventionally, in the ink jet method, a proposal for improving the uniformity of the shape has been made (for example, Patent Document 1). In Patent Document 1, a plurality of minute droplets are ejected into an element formation region, and the concentration of the constituent material in each ejected droplet is controlled to make the shape of the organic EL layer uniform.
JP 2001-215883 A

  However, in Patent Document 1, when the contact angle of the droplet with respect to the element formation region increases (when the wettability of the droplet decreases), the discharged droplet is biased without spreading in the element formation region. . As a result, an uneven shape resulting from the shape of each droplet is formed in the organic EL layer, and the uniformity of the shape (for example, film thickness uniformity within the element formation region, film thickness uniformity between the element regions, etc.) ).

  SUMMARY An advantage of some aspects of the invention is that it provides a method of manufacturing an electro-optical device and an electro-optical device that improve productivity by improving the uniformity of a light-emitting element shape. It is.

  The method for manufacturing an electro-optical device according to the present invention is the method for manufacturing an electro-optical device in which a light-emitting element is formed by discharging a liquid droplet containing a light-emitting element forming material onto an electrode containing a photocatalyst. Before discharging, the electrode was irradiated with ultraviolet light to induce lyophilicity of the photocatalyst with respect to the droplet.

  According to the method for manufacturing an electro-optical device of the present invention, the wettability of droplets forming a light-emitting element can be improved with respect to the electrode by the amount of inducing lyophilicity of the photocatalyst contained in the electrode. . Therefore, the uniformity of the shape of the light emitting element can be improved, and as a result, the productivity of the electro-optical device can be improved.

In the method of manufacturing the electro-optical device, when the ultraviolet light is irradiated, the atmosphere on the electrode is at least one of water vapor and oxygen.
According to this method of manufacturing an electro-optical device, chemical adsorption water, physical adsorption water, or the like can be applied to the electrode by an amount corresponding to at least one of water vapor and oxygen on the electrode. The lyophilicity can be further increased. As a result, the uniformity of the light emitting element shape can be improved by at least the amount of the atmosphere of either water vapor or oxygen.

In this method of manufacturing an electro-optical device, the ultraviolet light is irradiated only on a region on the electrode where the droplet is discharged.
According to the method for manufacturing the electro-optical device, only the region where the droplet is ejected is irradiated with the ultraviolet light, so that the surface state of the region where the droplet is not ejected can be maintained. Therefore, for example, by making the region where droplets are not ejected lyophobic, the droplets can be accommodated only in the region with improved lyophilicity, and the uniformity of the light emitting element shape can be further improved.

In this method of manufacturing an electro-optical device, the electrode is a transparent electrode made of indium oxide to which tin is added.
According to the method for manufacturing the electro-optical device, the lyophilicity of the transparent electrode can be improved, and the wettability of the liquid droplets discharged onto the transparent electrode can be improved. As a result, the uniformity of the shape of the light emitting element having the transparent electrode can be improved, and the productivity of the electro-optical device including the light emitting element can be improved.

  In this method of manufacturing an electro-optical device, the light emitting element is an electroluminescence element in which a hole transport layer composed of the droplets is formed between the transparent electrode and a back electrode.

  According to this method for manufacturing an electro-optical device, the uniformity of the shape of the hole transport layer can be improved, and the uniformity of the shape of the electroluminescent element can be improved. As a result, the productivity of the electro-optical device including the same electroluminescence element can be improved.

In this method for manufacturing an electro-optical device, the light emitting element is an organic electroluminescence element including the hole transport layer made of an organic material.
According to this method for manufacturing an electro-optical device, it is possible to improve the uniformity of the shape of the organic electroluminescent element including the hole transport layer made of an organic material, and the electro-optical device including the organic electroluminescent element. Productivity can be improved.

  In the method of manufacturing the electro-optical device, the light emitting element is an electroluminescence element in which a light emitting layer made of the droplet is formed between the transparent electrode and a back electrode.

  According to the method for manufacturing the electro-optical device, the uniformity of the shape of the light emitting layer can be improved, and the uniformity of the shape of the electroluminescence element can be improved. As a result, the productivity of the electro-optical device including the same electroluminescence element can be improved.

In this method for manufacturing an electro-optical device, the light emitting element is an organic electroluminescence element including the light emitting layer made of an organic material.
According to this method of manufacturing an electro-optical device, the uniformity of the shape of the organic electroluminescent element including the light-emitting layer made of an organic material can be improved, and the productivity of the electro-optical device including the organic electroluminescent element can be improved. Can be improved.

In the electro-optical device manufacturing method, the droplets are ejected from a droplet ejection device.
According to this method of manufacturing an electro-optical device, the uniformity of the light emitting element can be improved by the amount of forming fine droplets by the droplet discharge device.

The electro-optical device of the present invention includes a light-emitting element formed by the above-described method for manufacturing an electro-optical device.
According to the electro-optical device of the present invention, since the light-emitting element having a uniform shape is included, the productivity can be improved.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view showing an organic electroluminescence display (organic EL display) as an electro-optical device.

  As shown in FIG. 1, the organic EL display 10 includes a transparent substrate 11. The transparent substrate 11 is a non-alkali glass substrate formed in a rectangular shape, and a rectangular element forming region 12 is formed on the surface (element forming surface 11a). In the element formation region 12, a plurality of data lines Ly extending in the vertical direction (column direction) are formed at predetermined intervals. Each data line Ly is electrically connected to a data line driving circuit Dr1 disposed below the transparent substrate 11, respectively. The data line driving circuit Dr1 generates a data signal based on display data supplied from an external device (not shown), and outputs the data signal to the corresponding data line Ly at a predetermined timing.

  In the element formation region 12, a plurality of power supply lines Lv extending in the column direction are provided alongside the data lines Ly at a predetermined interval. Each power supply line Lv is electrically connected to a common power supply line Lvc formed below the element formation region 12 so as to supply drive power generated by a power supply voltage generation circuit (not shown) to each power supply line Lv. It has become.

  Furthermore, a plurality of scanning lines Lx extending in a direction (row direction) orthogonal to the data lines Ly and the power supply lines Lv are formed in the element formation region 12 at a predetermined interval. Each scanning line Lx is electrically connected to a scanning line driving circuit Dr2 formed on the left side of the transparent substrate 11, respectively. The scanning line drive circuit Dr2 selectively drives a predetermined scanning line Lx from a plurality of scanning lines Lx at a predetermined timing based on a scanning control signal supplied from a control circuit (not shown), and scans the scanning line Lx. A signal is output.

  A plurality of pixels 13 arranged in a matrix by being connected to the corresponding data line Ly, power supply line Lv, and scanning line Lx are formed at positions where the data line Ly and the scanning line Lx intersect. Within the pixel 13, a control element forming region 14 and a light emitting element forming region 15 are partitioned. The pixel 13 is protected by covering the upper side of the element forming region 12 with a rectangular sealing substrate 16 (two-dot chain line in FIG. 1).

Each pixel 13 in the present embodiment is a pixel that emits light of a corresponding color, and is a red pixel that emits red light, a green pixel that emits green light, or a blue pixel that emits blue light. is there. Each pixel 13 displays a full-color image on the back surface (display surface 11 b) side of the transparent substrate 11.

  Next, the pixel 13 described above will be described below. FIG. 2 is a schematic plan view showing the layout of the control element formation region 14 and the light emitting element formation region 15. 3 and 4 are schematic cross-sectional views showing the control element forming region 14 along the alternate long and short dash lines AA and BB in FIG. 2, respectively, and FIG. It is a schematic sectional drawing which shows the light emitting element formation area 15 along.

  First, the configuration of the control element formation region 14 will be described below. As shown in FIG. 2, a control element formation region 14 is formed below each pixel 13. The control element formation region 14 includes a first transistor (switching transistor) T <b> 1 and a second transistor ( A driving transistor T2 and a holding capacitor Cs are formed.

  As shown in FIG. 3, the switching transistor T1 includes a first channel film B1 in the lowermost layer. The first channel film B1 is an island-shaped p-type polysilicon film formed on the element formation surface 11a, and a first channel region C1 is formed at the center position thereof. Activated n-type regions (first source region S1 and first drain region D1) are formed on both the left and right sides of the first channel region C1. That is, the switching transistor T1 is a so-called polysilicon type TFT.

  On the upper side of the first channel region C1, a gate insulating film Gox and a first gate electrode G1 are formed in order from the element formation surface 11a side. The gate insulating film Gox is a light-transmitting insulating film such as a silicon oxide film, and is deposited on the upper side of the first channel region C1 and substantially the entire surface of the element forming surface 11a. The first gate electrode G1 is a low-resistance metal film such as tantalum or aluminum, and is formed at a position facing the first channel region C1, and is electrically connected to the scanning line Lx as shown in FIG. ing. As shown in FIG. 3, the first gate electrode G1 is electrically insulated by a first interlayer insulating film IL1 deposited on the upper side of the gate insulating film Gox.

  When the scanning line driving circuit Dr2 inputs a scanning signal to the first gate electrode G1 via the scanning line Lx, the switching transistor T1 is turned on based on the scanning signal.

  A data line Ly that penetrates the first interlayer insulating film IL1 and the gate insulating film Gox is electrically connected to the first source region S1. The first drain region D1 is electrically connected to the first drain electrode Dp1 that penetrates the first interlayer insulating film IL1 and the gate insulating film Gox. As shown in FIG. 3, the data line Ly and the first drain electrode Dp1 are electrically insulated by a second interlayer insulating film IL2 deposited on the upper side of the first interlayer insulating film IL1.

  When the scanning line driving circuit Dr2 sequentially selects the scanning lines Lx one by one based on line sequential scanning, the switching transistors T1 of the pixels 13 are sequentially turned on only during the selection period. When the switching transistor T1 is turned on, the data signal output from the data line driving circuit Dr1 is output to the first drain electrode Dp1 via the data line Ly and the switching transistor T1 (channel film B1).

As shown in FIG. 4, the driving transistor T2 is a polysilicon TFT including a channel film B2 having a second channel region C2, a second source region S2, and a second drain region D2. A second gate electrode G2 is formed above the second channel film B2 via a gate insulating film Gox. The second gate electrode G2 is a low resistance metal film such as tantalum or aluminum, and is electrically connected to the first drain electrode Dp1 of the switching transistor T1 and the lower electrode Cp1 of the holding capacitor Cs as shown in FIG. Has been. As shown in FIG. 4, the second gate electrode G2 and the lower electrode Cp1 are electrically insulated by the first interlayer insulating film IL1 deposited on the upper side of the gate insulating film Gox.

  The second source region S2 is electrically connected to the upper electrode Cp2 of the holding capacitor Cs that penetrates the first interlayer insulating film IL1. The upper electrode Cp2 is electrically connected to the corresponding power supply line Lv as shown in FIG. That is, between the second gate electrode G2 of the driving transistor T2 and the second source region S2, as shown in FIGS. 2 and 4, the holding capacitor Cs having the first interlayer insulating film IL1 as a capacitive film is provided. It is connected. The second drain region D2 is electrically connected to the second drain electrode Dp2 that penetrates the first interlayer insulating film IL1. The second drain electrode Dp2 and the upper electrode Cp2 are electrically insulated by a second interlayer insulating film IL2 deposited on the upper side of the first interlayer insulating film IL1.

  When the data signal output from the data line driving circuit Dr1 is output to the first drain region D1 via the switching transistor T1, the holding capacitor Cs accumulates charges corresponding to the output data signal. Subsequently, when the switching transistor T1 is turned off, a driving current relative to the charge accumulated in the holding capacitor Cs is output to the second drain region D2 via the driving transistor T2 (channel film B2).

Next, the configuration of the light emitting element formation region 15 will be described below.
As shown in FIG. 2, a rectangular light emitting element forming region 15 is formed on the upper side of each pixel 13. As shown in FIG. 5, an anode 20 as a transparent electrode is formed in the light emitting element formation region 15 and above the second interlayer insulating film IL2.

  The anode 20 is an electrode made of a thin film (ITO thin film) in which tin is added to indium oxide as a photocatalyst, and is a transparent conductive film having optical transparency. As shown in FIG. 4, one end of the anode 20 penetrates through the second interlayer insulating film IL2 and is electrically connected to the second drain region D2.

  A third interlayer insulating film IL3 such as a silicon oxide film that insulates the anodes 20 from each other is deposited on the anode 20. The third interlayer insulating film IL3 is formed with a rectangular through hole 21 that opens upward at a substantially central position of the anode 20, and the through hole 21 is formed on the upper surface of the anode 20. A discharge surface 20a for discharging a micro droplet 25b described later is formed at a position opposite to the hole 21. The discharge surface 20a becomes lyophilic for the hole layer droplet 25D (see FIG. 10) and the light emitting layer droplet 27D (see FIG. 11) in a lyophilic process (step 13 in FIG. 6) described later. Yes.

  A partition wall layer 22 is formed above the third interlayer insulating film IL3. The partition wall layer 22 is formed of a so-called positive photosensitive material in which, when exposure light Lpr (see FIG. 7) having a predetermined wavelength is exposed, only the exposed portion is soluble in a developer such as an alkaline solution. ing. In the partition wall layer 22, an accommodation hole 23 is formed that tapers upward at a position facing the through hole 21. The accommodation hole 23 is formed to have a size capable of accommodating a hole layer droplet 25D (see FIG. 10) and a light emitting layer droplet 27D (see FIG. 11) to be described later in the corresponding light emitting element formation region 15.

A partition wall 24 surrounding the light emitting element formation region 15 (the anode 20 and the through hole 21) is formed by the inner peripheral surface of the accommodation hole 23. Note that the upper surfaces of the partition wall 24 and the partition wall layer 22 repel the hole layer droplet 25D (see FIG. 10) and the light emitting layer droplet 27D (see FIG. 11) by a liquid repellency process (step 12 in FIG. 6) described later. It comes to liquefy.

A hole transport layer (hole layer) 25 made of a hole layer forming material 25s (see FIG. 10) as a light emitting element forming material is formed in the accommodation hole 23 and above the ejection surface 20a.
Note that the hole layer forming material 25s in the present embodiment includes, for example, a low molecular compound such as a benzidine derivative, a styrylamine derivative, a triphenylmethane derivative, a triphenylamine derivative, and a hydrazone derivative, or a part of these structures. Polymer compounds, polyaniline, polythiophene, polyvinyl carbazole, α-naphthylphenyldiamine, a mixture of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid (PEDOT / PSS) (Baytron P, trademark of Bayer), etc. It is a high molecular compound.

  On the upper side of the hole layer 25, a light emitting layer 27 made of a light emitting layer forming material 27s (see FIG. 11) is laminated. Note that the light emitting layer 27 in the present embodiment emits a corresponding light emitting layer forming material 27s (a red light emitting layer forming material that emits red light, a green light emitting layer forming material that emits green light, and blue light). Blue light emitting layer forming material).

An organic electroluminescence layer (organic EL layer) 30 is formed by the hole layer 25 and the light emitting layer 27.
Above the organic EL layer 30 and above the partition layer 22 (partition 24), a cathode 31 is formed as a back electrode made of a metal film having light reflectivity such as aluminum. The cathode 31 is formed so as to cover the entire surface of the element formation surface 11a, and is shared by each pixel 13 to supply a common potential to each light emitting element formation region 15.

That is, the anode 20, the organic EL layer 30, and the cathode 31 constitute an organic electroluminescence element (organic EL element) as a light emitting element.
When a driving current corresponding to the data signal is supplied to the anode 20 via the second drain region D2, the organic EL layer 30 emits light with a luminance corresponding to the driving current. At this time, light emitted from the organic EL layer 30 toward the cathode 31 (upper side in FIG. 4) is reflected by the cathode 31. Therefore, most of the light emitted from the organic EL layer 30 passes through the anode 20, the second interlayer insulating film IL2, the first interlayer insulating film IL1, the gate insulating film Gox, the element formation surface 11a, and the transparent substrate 11. Then, the light is emitted outward from the back surface (display surface 11b) side of the transparent substrate 11. That is, an image based on the data signal is displayed on the display surface 11 b of the organic EL display 10.

  An adhesive layer 32 made of an epoxy resin or the like is formed on the upper side of the cathode 31, and a sealing substrate 16 that covers the element formation region 12 is attached via the adhesive layer 32. The sealing substrate 16 is an alkali-free glass substrate, and prevents the pixel 13 and the various wirings Lx, Ly, Lv from being oxidized.

  Next, the manufacturing method of the organic EL display 10 described above will be described below. FIG. 6 is a flowchart for explaining a manufacturing method of the organic EL display 10, and FIGS. 7 to 11 are explanatory views for explaining a manufacturing method of the organic EL display 10.

  As shown in FIG. 6, first, various wirings Lx, Ly, Lv, Lvc and transistors T1, T2 are formed on the element forming surface 11a of the transparent substrate 11, and the organic EL layer pre-process for patterning the partition wall layer 22 is performed ( Step S11). FIG. 7 is an explanatory view illustrating the organic EL layer pre-process.

That is, in the organic EL layer pre-process, first, a polysilicon film crystallized by an excimer laser or the like is formed on the entire element forming surface 11a, and the polysilicon film is patterned to form the channel films B1 and B2. Next, a gate insulating film Gox made of a silicon oxide film or the like is formed on the entire upper surfaces of the channel films B1 and B2 and the element formation surface 11a, and a low resistance metal film such as tantalum is formed on the entire upper surface of the gate insulating film Gox. accumulate. Then, the low-resistance metal film is patterned to form the gate electrodes G1, G2, the lower electrode Cp1 of the storage capacitor Cs, and the scanning line Lx.

  When the gate electrodes G1 and G2 are formed, n-type impurity regions are formed in the channel films B1 and B2, respectively, by ion doping using the gate electrodes G1 and G2 as a mask. Thus, the channel regions C1 and C2, the source regions S1 and S2, and the drain regions D1 and D2 are formed. When the source regions S1 and S2 and the drain regions D1 and D2 are formed in the channel films B1 and B2, respectively, silicon oxide is formed on the entire upper surfaces of the gate electrodes G1 and G2, the lower electrode Cp1, the scanning line Lx, and the gate insulating film Gox. A first interlayer insulating film IL1 made of a film or the like is deposited.

  When the first interlayer insulating film IL1 is deposited, a pair of contact holes is patterned in the first interlayer insulating film IL1 at positions facing the source regions S1, S2 and the drain regions D1, D2. Next, a metal film such as aluminum is deposited in the contact hole and on the entire upper surface of the first interlayer insulating film IL1, and the metal film is patterned to form data lines Ly and storage capacitors corresponding to the source regions S1 and S2. Cs upper electrodes Cp2 are formed respectively. At the same time, the drain electrodes Dp1, Dp2 corresponding to the drain regions D1, D2 are formed. Then, a second interlayer insulating film IL2 made of a silicon oxide film or the like is deposited on the entire upper surface of the data line Ly, the upper electrode Cp2, the drain regions D1 and D2, and the first interlayer insulating film IL1. Thereby, the switching transistor T1 and the driving transistor T2 are formed.

  When the second interlayer insulating film IL2 is deposited, a via hole is formed at a position opposite to the second drain region D2 in the second interlayer insulating film IL2. Next, a transparent conductive film made of ITO is deposited by sputtering or the like in the via hole and on the entire upper surface of the second interlayer insulating film IL2, and is connected to the second drain region D2 by patterning the transparent conductive film. The anode 20 is formed. When the anode 20 is formed, a third interlayer insulating film IL3 made of a silicon oxide film or the like is deposited on the entire upper surface of the anode 20 and the second interlayer insulating film IL2.

  When the third interlayer insulating film IL3 is deposited, as shown in FIG. 7, a partition layer 22 is formed by applying a photosensitive polyimide resin or the like on the entire upper surface of the third interlayer insulating film IL3. Then, when exposure light Lpr having a predetermined wavelength is exposed to the partition wall layer 22 at a position opposite to the anode 20 through the mask Mk and developed, the accommodation hole having the partition wall 24 as the inner peripheral surface is formed in the partition wall layer 22. 23 is patterned.

When the accommodation hole 23 is patterned, the third interlayer insulating film IL3 is patterned using the partition layer 22 as a mask, and a through hole 21 communicating with the accommodation hole 23 is formed above the anode 20.
Thus, various wirings Lx, Ly, Lv, Lvc and the transistors T1, T2 are formed on the element formation surface 11a, and the organic EL layer pre-process for patterning the accommodation hole 23 is completed.

  As shown in FIG. 6, when the organic EL layer pre-process is completed (step S11), a liquid repellent process is performed to make the surfaces of the partition wall 24 and the partition wall layer 22 liquid repellent (step S12). FIG. 8 is an explanatory diagram for explaining the liquid repellent treatment process.

That is, in the liquid repellent treatment step, as shown in FIG. 8, the entire surface of the transparent substrate 11 on which the element is formed 11a is exposed to fluorine-based plasma Ps (for example, plasma using CF4 as a source gas). Thereby, an organic group containing fluorine is formed on the upper surface of the partition layer 22 and the surface of the partition 24 to impart liquid repellency.

  As shown in FIG. 6, when the lyophobic treatment process is completed (step S12), a lyophilic process for lyophilicizing the ejection surface 20a is performed (step S13). FIG. 9 is an explanatory diagram for explaining the lyophilic process.

  That is, in the lyophilic process, as shown in FIG. 9, first, the transparent substrate 11 is disposed in the ultraviolet processing apparatus, and the element forming surface 11 a is opposed to the ultraviolet lamp 33. Next, water vapor H is supplied into the ultraviolet processing apparatus, and a water vapor atmosphere is formed on the element formation surface 11a (discharge surface 20a). Subsequently, a mask Mk2 having a through hole at a position facing the ejection surface 20a is disposed on the element formation surface 11a. Then, ultraviolet light Luv having a wavelength of 215 nm (y-line) is emitted from the ultraviolet lamp 33, and the ejection surface 20a is irradiated with the ultraviolet light Luv through the mask Mk2. Then, the photocatalyst added to the anode 20 is activated, and the activated photocatalyst forms chemically adsorbed water (for example, hydroxyl group) on the discharge surface 20a, and the physically adsorbed water is adsorbed on the chemically adsorbed water. That is, the discharge surface 20a (anode 20) induces lyophilicity.

  At this time, the region other than the ejection surface 20a is protected by the mask Mk2. Therefore, the liquid repellency of the partition layer 22 and the partition wall 24 subjected to the liquid repellency treatment and the surface characteristics of the anode 20 other than the discharge surface 20a are maintained in the lyophilic process described above.

  As shown in FIG. 6, when the discharge surface 20a is made lyophilic (step 13), the positive hole layer 25 is formed by forming the positive hole layer droplet 25D made of the positive hole layer forming material 25s in the accommodation hole 23. A pore layer forming step is performed (step S14). FIG. 10 is an explanatory diagram for explaining the hole layer forming step.

First, the configuration of the droplet discharge device for forming the hole layer droplet 25D will be described below.
As shown in FIG. 10, a nozzle plate 36 is provided in the liquid discharge head 35 constituting the droplet discharge apparatus in the present embodiment. On the lower surface (nozzle formation surface 36a) of the nozzle plate 36, a large number of nozzles 36n for discharging liquid are formed upward. Above each nozzle 36n, a liquid supply chamber 37 is formed which communicates with a liquid storage tank (not shown) and can supply liquid into the nozzle 36n. Above each liquid supply chamber 37, a vibration plate 38 that reciprocates in the vertical direction and expands or contracts the volume in the liquid supply chamber 37 is disposed. Piezoelectric elements 39 that extend in the vertical direction and vibrate the vibration plate 38 are disposed above the vibration plate 38 and at positions opposite to the liquid supply chambers 37.

  As shown in FIG. 10, the transparent substrate 11 transported to the droplet discharge device has the element formation surface 11a parallel to the nozzle formation surface 36a and the center position of each accommodation hole 23 directly below the nozzle 36n. Is positioned and positioned.

Here, the hole layer forming liquid 25L generated by dissolving the hole layer forming material 25s in the lower layer solvent is supplied into the liquid supply chamber 37.
The lower layer solvent in this embodiment is a hydrophilic liquid, such as N-methylpyrrolidone or 1,3-dimethyl-2-imidazolidinone.

When a drive signal for forming the hole layer droplet 25D is input to the liquid discharge head 35, the piezoelectric element 39 expands and contracts based on the drive signal, and the volume of the liquid supply chamber 37 expands and contracts. At this time, when the volume of the liquid supply chamber 37 is reduced, the hole layer forming liquid 25L in an amount corresponding to the reduced volume is discharged from each nozzle 36n as the fine droplet 25b. The discharged micro droplets 25b land on the upper surface of the anode 20 in the accommodation hole 23, respectively. Subsequently, the liquid supply chamber 37
When the volume of the liquid is expanded, the hole layer forming liquid 25L corresponding to the expanded volume is supplied into the liquid supply chamber 37 from a liquid storage tank (not shown). That is, the liquid discharge head 35 discharges the hole layer forming liquid 25 </ b> L having a predetermined capacity toward the accommodation hole 23 by the enlargement / reduction of the liquid supply chamber 37. At this time, the liquid discharge head 35 discharges the minute droplets 25b as much as the hole layer forming material 25s included in the hole layer droplets 25D forms a desired film thickness.

  And the minute droplet 25b discharged into the accommodation hole 23 is uniformly spread over the entire upper surface of the anode 20 by the amount of lyophilic treatment described above. The fine liquid droplet 25b that spreads uniformly spreads and eventually forms a hole layer liquid droplet 25D having a hemispherical surface due to the surface tension and the liquid repellency of the partition wall 24, as shown by the two-dot chain line in FIG. To do.

  When the hole layer droplet 25D is formed, the transparent substrate 11 (hole layer droplet 25) is then placed under a predetermined reduced pressure to evaporate the lower layer solvent of the hole layer droplet 25D. The forming material 25s is cured. The hole layer forming material 25s to be cured has its shape (for example, the film thickness distribution in the light emitting element forming region 15 or the film thickness distribution between the light emitting element forming regions 15) by the amount that uniformly spreads over the entire upper surface of the anode 20. The hole layer 25 is made uniform.

  As shown in FIG. 6, when the hole layer 25 is formed (step S14), a light emitting layer forming process for forming the light emitting layer 27 in each accommodation hole 23 is performed (step S15). FIG. 11 is an explanatory diagram for explaining a light emitting layer forming step.

  That is, in the light emitting layer forming step, as shown in FIG. 11, as in the hole layer forming step, the microdroplet 27b of the light emitting layer forming liquid 27L containing the light emitting layer forming material 27s of each color is handled from each nozzle 36n. The light-emitting layer 27 is formed by drying the light-emitting layer droplets 27D that are ejected onto the hole layer 25 to be formed and formed by the ejected minute droplets 27b.

  At this time, the minute droplets 27b discharged onto the hole layer 25 are uniformly spread by the amount that the shape of the hole layer 25 is uniformly formed by the lyophilic process described above, and the shape of the light emitting layer 27 is made uniform. That is, the shape of the organic EL layer 30 is made uniform.

  As shown in FIG. 6, when the light emitting layer 27 (organic EL layer 30) is formed (step S15), the cathode 31 is formed on the light emitting layer 27 (organic EL layer 30) and the partition wall layer 22, and the pixel 13 is sealed. An organic EL layer post-process is performed (step 16). That is, a cathode 31 made of a metal film such as aluminum is deposited on the entire upper surface of the organic EL layer 30 and the partition wall layer 22 to form an organic EL element consisting of the anode 20, the organic EL layer 30 and the cathode 31. When the organic EL element is formed, an epoxy resin or the like is applied to the entire upper surface of the cathode 31 (pixel 13) to form an adhesive layer 32, and the sealing substrate 16 is attached to the transparent substrate 11 through the adhesive layer 32. .

Thereby, the organic EL display 10 in which the film thickness distribution of the organic EL layer 30 is made uniform in the element forming surface 11a can be manufactured.
Next, effects of the present embodiment configured as described above will be described below.

  (1) According to the above embodiment, before discharging the micro droplet 25b made of the hole layer forming liquid 25L onto the discharge surface 20a, the discharge surface 20a is irradiated with the ultraviolet light Luv to make the photocatalyst lyophilic. It was made to induce (step S13). Accordingly, it is possible to form the hole layer droplet 25D that spreads over the entire discharge surface 20a by the amount that induces the lyophilicity of the photocatalyst. As a result, the shape of the hole layer 25 can be made uniform, and the uniformity of the shape of the organic EL layer 30 (organic EL element) can be improved. As a result, the productivity of the organic EL display 10 including the organic EL layer 30 can be improved.

  (2) According to the above-described embodiment, when the discharge surface 20a is irradiated with the ultraviolet light Luv, the element forming surface 11a is in a water vapor H atmosphere. Therefore, the lyophilicity by the activated photocatalyst can be improved by the amount of water vapor H interposed. As a result, the shape of the hole layer 25 can be made more uniform.

  (3) According to the above embodiment, when the ultraviolet light Luv is applied to the discharge surface 20a, the mask Mk2 covers the region other than the discharge surface 20a. Therefore, the liquid repellency of the partition layer 22 and the partition wall 24 subjected to the liquid repellent treatment and the surface characteristics of the anode 20 other than the discharge surface 20a can be maintained, and only the discharge surface 20a can be made lyophilic. As a result, the hole layer droplet 25D can be repelled by the surface of the partition wall 24 and the upper surface of the partition layer 22, and leakage of the hole layer droplet 25D can be avoided. Therefore, the hole layer 25 corresponding to the amount of the ejected microdroplets 25b can be reliably formed on the ejection surface 20a, and the uniformity of the shape between the organic EL layers 30 (organic EL elements) can be improved. Can do.

  (4) According to the above embodiment, the hole layer droplet 25D is formed by the micro droplet 25b discharged from the droplet discharge device. Therefore, a desired amount of the hole layer forming material 25 s can be reliably accommodated in the accommodation hole 23. As a result, the organic EL layer 30 (organic EL element) having a more uniform shape can be formed as compared with other liquid phase processes (for example, spin coating method).

In addition, you may change the said embodiment as follows.
In the above embodiment, the photocatalyst is embodied in indium oxide. However, the photocatalyst is not limited to this, but may be titanium dioxide, zinc oxide, tin oxide, strontium titanate, tungsten oxide, bismuth oxide, iron oxide, or the like. May be.
In the above embodiment, the organic EL element is configured as a bottom emission type, and the photocatalyst is included in the transparent electrode. Not limited to this, the organic EL element may be configured as a top emission type, and the back electrode may contain a photocatalyst.
In the above embodiment, the element formation surface 11a side is irradiated with the ultraviolet light Luv with the water vapor H atmosphere. However, the present invention is not limited to this. For example, the element formation surface 11a side is irradiated with the ultraviolet light Luv. Thus, lyophilicity may be induced by chemically adsorbed water (for example, hydroxyl group) formed on the ejection surface 20a or physical adsorbed water adsorbed on the chemically adsorbed water. Or you may make it irradiate the ultraviolet light Luv on the element formation surface 11a side in air | atmosphere.
In the above embodiment, the ultraviolet light Luv is irradiated through the mask Mk2, but the present invention is not limited to this, and the ultraviolet light Luv may be irradiated without arranging the mask Mk2 in an air atmosphere.
In the above embodiment, the hole layer forming material 25s and the light emitting layer forming material are embodied as an organic polymer material, but the present invention is not limited to this, and the hole layer forming material 25s and the light emitting layer forming material may be formed of a known organic low molecular material or inorganic material.
In the above embodiment, the organic EL layer 30 is constituted by the hole transport layer 25 and the light emitting layer 27. However, the present invention is not limited thereto, and an electron injection made of a laminated film of lithium fluoride and calcium or the like is formed on the light emitting layer 27. You may make it the structure which provides a layer.
In the above embodiment, the control element formation region 14 includes the switching transistor T1 and the driving transistor T2. However, the present invention is not limited to this. For example, depending on the desired element design, one transistor or a number of transistors You may make it the structure which consists of a transistor or many capacitors.
In the above embodiment, the organic EL layer 30 is formed by the ink jet method. The method for forming the organic EL layer 30 is not limited to this. For example, the hole layer droplet 25D or the light emitting layer droplet 27D may be formed by a liquid applied by a spin coating method or the like. Any method may be used as long as the organic EL layer 30 is formed by curing.
In the above embodiment, the micro droplet 25b is ejected by the piezoelectric element 39. However, the present invention is not limited to this. For example, a resistance heating element is provided in the liquid supply chamber 37, and bubbles formed by heating the resistance heating element Alternatively, the micro droplet 25b may be discharged by rupturing.
In the above embodiment, the electro-optical device is embodied as the organic EL display 10, but is not limited thereto, and may be a backlight mounted on a liquid crystal panel or the like, or includes a planar electron-emitting device. Further, a field effect display (FED, SED, etc.) using light emission of a fluorescent material by electrons emitted from the element may be used.

1 is a schematic plan view showing an organic EL display embodying the present invention. Similarly, the schematic plan view which shows a pixel. Similarly, a schematic sectional view showing a control element formation region. Similarly, a schematic sectional view showing a control element formation region. Similarly, the schematic sectional drawing which shows a light emitting element formation area. Similarly, the flowchart explaining the manufacturing process of an electro-optical apparatus. Similarly, the explanatory view explaining the manufacturing process of the electro-optical device. Similarly, the explanatory view explaining the manufacturing process of the electro-optical device. Similarly, the explanatory view explaining the manufacturing process of the electro-optical device. Similarly, the explanatory view explaining the manufacturing process of the electro-optical device. Similarly, the explanatory view explaining the manufacturing process of the electro-optical device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Organic EL display as an electro-optical device, 11 ... Transparent substrate, 15 ... Light emitting element formation area, 20 ... Anode as a transparent electrode, 25 ... Hole transport layer, 27 ... Light emitting layer, 30 ... Organic EL layer, 31 ... a cathode as a back electrode, 35 ... a liquid discharge head constituting a droplet discharge device, H ... water vapor, Luv ... ultraviolet light.

Claims (10)

In the method of manufacturing an electro-optical device in which a light-emitting element is formed by discharging droplets containing a light-emitting element forming material on an electrode containing a photocatalyst,
A method for manufacturing an electro-optical device, wherein the lyophilicity of the photocatalyst with respect to the droplet is induced by irradiating the electrode with ultraviolet light before discharging the droplet. The method of manufacturing the electro-optical device according to claim 1,
A method of manufacturing an electro-optical device, wherein when the ultraviolet light is irradiated, an atmosphere of at least one of water vapor and oxygen is provided on the electrode. In the manufacturing method of the electro-optical device according to claim 1 or 2,
A method of manufacturing an electro-optical device, wherein the ultraviolet light is irradiated only on a region on the electrode where the droplet is discharged. In the manufacturing method of the electro-optical device according to any one of claims 1 to 3,
The method of manufacturing an electro-optical device, wherein the electrode is a transparent electrode made of indium oxide to which tin is added. The method of manufacturing an electro-optical device according to claim 4,
The method of manufacturing an electro-optical device, wherein the light-emitting element is an electroluminescence element in which a hole transport layer made of the droplet is formed between the transparent electrode and a back electrode. The method for manufacturing an electro-optical device according to claim 5,
The method of manufacturing an electro-optical device, wherein the light-emitting element is an organic electroluminescence element including the hole transport layer made of an organic material. The method of manufacturing an electro-optical device according to claim 6,
The method of manufacturing an electro-optical device, wherein the light-emitting element is an electroluminescence element in which a light-emitting layer made of the droplet is formed between the transparent electrode and a back electrode. The method of manufacturing an electro-optical device according to claim 7.
The method of manufacturing an electro-optical device, wherein the light-emitting element is an organic electroluminescence element including the light-emitting layer made of an organic material. In the manufacturing method of the electro-optical device according to any one of claims 1 to 8,
A method of manufacturing an electro-optical device, wherein the droplets are discharged from a droplet discharge device. An electro-optical device comprising a light-emitting element formed by the electro-optical device manufacturing method according to claim 1.

Images