JP4678400B2 - Active matrix substrate, electro-optical device, method of manufacturing electro-optical device, and electronic apparatus - Google Patents

Description

  The present invention relates to an active matrix substrate, an electro-optical device, a method for manufacturing the electro-optical device, and an electronic apparatus.

  2. Description of the Related Art In recent years, electro-optical devices using organic substances in a light emitting layer have been provided as spontaneous light emitting displays that replace liquid crystal displays. As such an electro-optical device, a transparent substrate is currently used as a TFT substrate for forming a TFT (thin film transistor) serving as a switching element, and light emitted from the light emitting layer is transmitted through the transparent substrate, so that the external It is common to emit light.

By the way, in the electro-optical device of the type in which the light passes through the transparent substrate, since the TFT serving as the switching element is formed on the TFT substrate, the light cannot be transmitted through the TFT portion. Due to the low rate, there is a problem that it is difficult to increase the size of the display using this (large screen).
That is, when the size is increased, it is necessary to widen the wiring width in order to reduce the resistance of each wiring, for example, the scanning line and the signal line. However, if doing so, the aperture ratio becomes lower, and desired good This is because it becomes difficult to obtain image quality.

  Therefore, in order to solve such problems and enable a large display (large screen), the light is not transmitted through the transparent substrate, but is emitted from the opposite side of the TFT substrate. Practical use is planned.

In the type in which light is emitted to the side opposite to the substrate, it is necessary to form an electrode on the side from which light from the light emitting layer is emitted, that is, a counter electrode, using a transparent conductive material.
However, as a transparent conductive material that can withstand practical use, there is no sufficiently low resistance material, and therefore, even in an electro-optical device of a type that emits light to the side opposite to the substrate, its large screen, Furthermore, there is a problem that it is difficult to achieve high definition.

  That is, for example, an electro-optical device including an organic EL element has a driving method based on electric current, and thus, for example, a liquid crystal element having a driving method based on a voltage performs uniform display between pixels. In order to ensure the internal uniformity, it is necessary to perform control so that the current flowing through each pixel becomes more uniform.

  However, in an electro-optical device composed of organic EL elements, as described above, when the size of the electro-optical device is increased (large screen), it is difficult for current to flow to the end side of the wiring. Therefore, it is necessary to make the current flow evenly to the end of the wiring. In addition, in the case of high definition, it is necessary to shorten the selection time for scanning and to sufficiently reduce the wiring resistance. As described above, at present, there is no material having a sufficiently low resistance as a transparent conductive material that can withstand practical use, and therefore, an increase in size and definition cannot be achieved.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an active matrix substrate in which the resistance of the counter electrode is reduced in order to enable the electro-optical device to be increased in size and definition. To provide an optical device, a method for manufacturing an electro-optical device, and an electronic apparatus.

  In order to achieve the above object, an active matrix substrate of the present invention is an active matrix substrate comprising a plurality of pixel electrodes separated by a partition made of an insulating material on a substrate having an active element, A conductive material is disposed at a position insulated from the pixel electrode.

  According to this active matrix substrate, since the conductive material is disposed on the partition wall, for example, it is formed separately from the counter electrode and provided in a state of being connected to the counter electrode. The substantial resistance of the counter electrode combined with the material is lowered, and this makes it possible to equalize the current to the end of the wiring.

In the active matrix substrate, the active element is preferably a thin film transistor.
In this way, the active matrix substrate can be reduced in thickness and size.

In the active matrix substrate, the conductive material is formed in a stripe shape or a lattice shape.
In this way, the resistance of the counter electrode can be lowered so as to affect each pixel almost equally, so that uniform display is performed between the pixels, thereby ensuring in-plane uniformity. This is advantageous.

Further, in the active matrix substrate, it is preferable that a recess is formed on the upper surface of the partition wall, and the conductive material is provided in the recess.
In this case, for example, when a conductive material is discharged and applied in the recess by an ink jet method, it is possible to prevent the conductive material from flowing down from the upper surface of the partition wall and conducting with the pixel electrode.
Another active matrix substrate of the present invention is characterized in that a planarizing film is formed above an active element, and a plurality of pixel electrodes are arranged on the planarizing film.
In the active matrix substrate, the plurality of pixel electrodes may be separated by a partition made of an insulating material. Furthermore, a conductive material may be disposed on the partition wall. For example, an organic electroluminescence element may be disposed on the active matrix substrate as an electro-optical element to form an electro-optical device. In this electro-optical device, since the pixel electrode is provided with a planarization film, light emitted from the organic electroluminescence element can be extracted without being scattered or scattered. This is particularly effective when light is extracted to the side opposite to the active matrix substrate.

  In the electro-optical device according to the aspect of the invention, a multilayer body including a plurality of pixel electrodes separated by a partition made of an insulating material on a base body having an active element, a light emitting layer disposed on the pixel electrode, and the multilayer A conductive portion insulated from the pixel electrode, and the conductive portion is connected to the counter electrode. The counter electrode is disposed on the body. It is said.

  According to this electro-optical device, since the conductive portion is arranged on the partition wall, the resistance of the substantial counter electrode in which the conductive portion is combined with the counter electrode is reduced, and thereby the current to the end of the wiring is made uniform. For example, the display as an electro-optical device can be increased in size (larger screen) and higher in definition.

In the electro-optical device, the active element is preferably a thin film transistor.
In this way, the device can be made thinner and smaller.

In the electro-optical device, it is preferable that the conductive portion is formed in a stripe shape or a lattice shape.
In this way, the resistance of the counter electrode can be lowered so as to affect each pixel almost equally, so that uniform display is performed between the pixels, thereby ensuring in-plane uniformity. This is advantageous.

In the electro-optical device, the light emitting layer is preferably an organic electroluminescent material.
In this way, the electro-optical device is made of an organic electroluminescence element.

In the electro-optical device, it is preferable that a material for forming the conductive portion is a material having higher conductivity than a material for forming the counter electrode.
If it does in this way, the degree of substantial resistance fall of the counter electrode by an electroconductive part can be raised.

In the electro-optical device, it is preferable that a concave portion is formed on the upper surface of the partition wall, and the conductive portion is formed in the concave portion.
In this way, for example, when a conductive material is discharged and applied in the recess by an ink jet method, the conductive material can flow down from the upper surface of the partition wall and be prevented from conducting with the pixel electrode. it can.

In the electro-optical device, it is preferable that a hole injection layer or a hole transport layer is provided on the side of the light emitting layer that functions as an anode of the pixel electrode and the counter electrode.
If it does in this way, the luminous ability of a light emitting layer will become high with a positive hole injection layer or a positive hole transport layer, and a more favorable light emission characteristic will be acquired.

In the electro-optical device, it is preferable that light from the light emitting layer is extracted via the counter electrode side.
If it does in this way, what is not transparent as a base can be used because light radiate | emits from the opposite side to a base.

In the electro-optical device, it is preferable that the pixel electrode is disposed on the active element, and further, a planarizing film is formed on the active element, and the pixel electrode is disposed on the planarizing film. It is preferable.
In this way, it becomes possible to form the pixel electrode without being affected by the active element. In particular, when the pixel electrode is arranged on the planarization film, the pixel electrode is enlarged to the limit of the design rule. It becomes possible.

In the electro-optical device, it is preferable that light from the light emitting layer is extracted via the pixel electrode side.
If it does in this way, what is not transparent as a counter electrode can be used because light radiate | emits from the base | substrate side.

  In the method of manufacturing the electro-optical device according to the present invention, when the electro-optical device according to claim 6 is manufactured, the partition wall separating the pixel electrode and the pixel and the conductive portion on the partition wall are formed on the substrate, and then the partition wall is formed. A light emitting layer is formed in a region partitioned by the above.

  According to the method for manufacturing the electro-optical device, the light emitting layer is formed after the conductive portion is formed, and therefore the process of forming the conductive portion can be performed without affecting the light emitting layer. In addition, since the resistance of the counter electrode can be substantially reduced by forming the conductive portion, it is possible to equalize the current to the end of the wiring, for example, to increase the size of the display as an electro-optical device (large screen) ), High definition can be achieved.

In the method of manufacturing the electro-optical device, the light emitting layer can be formed by applying a material constituting the region light emitting layer partitioned by the partition wall by an ink jet method. In this way, the material of the light emitting layer can be selectively ejected and applied. Therefore, for example, by arranging materials emitting light of red, green, and blue, an electro-optical device for full color display can be easily obtained. Can be manufactured.
A spin coating method, a dip coating method, a vapor deposition method, or the like can be used instead of the ink jet method.

In the method of manufacturing the electro-optical device, the conductive portion can be formed by forming a concave portion on the upper surface of the partition wall and applying a material for the conductive portion in the concave portion by an ink jet method.
In this way, it is possible to prevent a problem that the conductive material flows down from the upper surface of the partition wall and becomes conductive with the pixel electrode.
A spin coating method, a dip coating method, a vapor deposition method, or the like can be used instead of the ink jet method.

Further, in the method of manufacturing the electro-optical device, the upper surface of the partition wall is subjected to a lyophilic process and the side surface is subjected to a liquid repellent treatment, and the upper surface part of the partition wall is immersed in a liquid material prepared in a liquid state. Preferably, a conductive material is attached to the upper surface of the substrate, and then the conductive material is cured to form a conductive portion.
In this way, it is possible to relatively easily form the conductive portion on the partition wall.

In the method of manufacturing the electro-optical device, when forming the partition wall and the conductive portion on the partition wall, the partition wall forming material is formed, and then the conductive material is formed on the film made of the partition wall forming material. It is preferable to form a conductive part by patterning a film made of a conductive material and then forming a conductive part, and then patterning a film made of a partition forming material using the obtained conductive part as a mask.
In this case, for example, when patterning is performed by a photolithography process, the photolithography process can be performed once without performing the partition wall formation and the conductive portion formation, and thus the process can be simplified. Can be achieved.

In the method of manufacturing the electro-optical device, a hole injection layer or a hole transport layer may be provided on an electrode side that functions as an anode of the pixel electrode and the counter electrode with respect to the region partitioned by the partition. It is preferable to form the hole injection layer or the hole transport layer by applying the material by an ink jet method.
If it does in this way, the material of a positive hole injection layer or a positive hole transport layer can be selectively discharged and apply | coated to the area | region divided by the partition. In addition, by forming the hole injection layer or the hole transport layer in this manner, the light emission ability of the light emitting layer can be increased, and thus better light emission characteristics can be obtained.

The electronic apparatus of the present invention is characterized by using the electro-optical device or the electro-optical device obtained by the manufacturing method.
According to this electronic device, since the electro-optical device in which the resistance of the counter electrode is substantially reduced due to the formation of the conductive portion on the partition wall, the current to the end of the wiring is made uniform. By being able to do so, it becomes possible to increase its size (large screen) and high definition.

In the electronic apparatus, it is preferable that an antireflection film is provided on the light emitting side of the electro-optical device.
In this way, it is possible to prevent a decrease in display performance due to reflection at the conductive portion formed on the partition.

The present invention will be described in detail below.
First, a schematic configuration of the electro-optical device of the present invention will be described.
FIGS. 1 and 2 show an example in which the active matrix substrate of the present invention and the electro-optical device using the same are applied to an active matrix display. In these drawings, reference numeral 1 denotes a display.

  As shown in FIG. 1 which is a circuit diagram, the display 1 includes a plurality of scanning lines 131 and a plurality of signal lines 132 extending in a direction intersecting with the scanning lines 131 on a substrate (not shown). A plurality of common power supply lines 133 extending in parallel to the signal lines 132 are wired, and each pixel has a pixel (pixel area element) 1A at each intersection of the scanning lines 131 and the signal lines 132. Is.

For the signal line 132, a data side driving circuit 3 including a shift register, a level shifter, a video line, and an analog switch is provided.
On the other hand, for the scanning line 131, a scanning side driving circuit 4 including a shift register and a level shifter is provided. In each of the pixel regions 1A, a first thin film transistor 142 to which a scanning signal is supplied to the gate electrode through the scanning line 131 and an image signal supplied from the signal line 132 through the first thin film transistor 142 are provided. , A second thin film transistor 143 to which an image signal held by the storage capacitor cap is supplied to the gate electrode, and the second thin film transistor 143 and the common power supply line 133 are electrically connected to each other. A pixel electrode 141 into which a driving current flows from the common power supply line 133 sometimes and a light emitting unit 140 sandwiched between the pixel electrode 141 and the reflective electrode 154 are provided.

  Under such a configuration, when the scanning line 131 is driven and the first thin film transistor 142 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor cap, and according to the state of the holding capacitor cap. Thus, the conduction state of the second thin film transistor 143 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 141 through the channel of the second thin film transistor 143, and further a current flows to the reflective electrode 154 through the light emitting unit 140, so that the light emitting unit 140 has a current amount flowing therethrough. In response to the light emission.

  Here, as shown in FIG. 2A, the planar structure of each pixel 1A is such that the four sides of the pixel electrode 141 having a rectangular planar shape are the signal line 132, the common power supply line 133, the scanning line 131, and other pixels not shown. The arrangement is surrounded by scanning lines for electrodes. In FIG. 2A, the counter electrode and the partition are removed. Also, the internal structure in the vicinity of the pixel 1A is located above the second thin film transistor 143 as shown in FIG. 2B, which is a cross-sectional view taken along the line AA in the vicinity of the pixel 1A in FIG. A partition wall 150 is formed, a conductive portion 151 is formed on the partition wall 150, and a reflective electrode 154 and a sealing layer 160 are formed to cover the partition wall 150 and the conductive portion 151. In FIG. 2B, reference numeral 143 denotes a thin film transistor, 170 denotes a gate insulating film, 140A denotes a hole injection layer, 140B denotes a light emitting layer, and 140C denotes an electron transport layer.

Next, the manufacturing method of such a display 1 is demonstrated using FIGS. 3 to 5, only the single pixel 1 </ b> A is illustrated for simplifying the description.
First, a substrate is prepared. Here, the display 1 of the present invention is configured to take out light emitted by a light emitting layer, which will be described later, from the side opposite to the substrate (TFT substrate), that is, from the counter electrode side. Unlike the case of taking out from the substrate, it is not necessary to use a transparent or translucent substrate material. However, even if it is a transparent material, for example, inexpensive soda glass may be used. In that case, it is preferable to apply silica coating to this because it has the effect of protecting soda glass that is weak against acid-alkali, and also has the effect of improving the flatness of the substrate.
When an opaque substrate is used, ceramics such as alumina, a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation, a thermosetting resin, a thermoplastic resin, or the like can be used.

  In this example, a substrate (TFT substrate) 121 made of soda glass or the like is prepared as a substrate as shown in FIG. In response to this, a base protective film (not shown) made of a silicon oxide film having a thickness of about 200 to 500 nm is formed by plasma CVD using TEOS (tetraethoxysilane), oxygen gas, or the like as a raw material as necessary. .

Next, the temperature of the substrate 121 is set to about 350 ° C., and the semiconductor film 200 made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the base protective film by plasma CVD. Next, a crystallization process such as laser annealing or solid phase growth is performed on the semiconductor film 200 to crystallize the semiconductor film 200 into a polysilicon film. In the laser annealing method, for example, a line beam having a beam length of 400 mm is used with an excimer laser, and the output intensity is set to 200 mJ / cm ² , for example. With respect to the line beam, the line beam is scanned so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.

  Next, as shown in FIG. 3B, the semiconductor film (polysilicon film) 200 is patterned into an island-shaped semiconductor film 210, and the surface thereof is formed by plasma CVD using TEOS, oxygen gas, or the like as a raw material. A gate insulating film 220 made of a silicon oxide film or a nitride film having a thickness of about 60 to 150 nm is formed. Note that the semiconductor film 210 serves as a channel region and a source / drain region of the second thin film transistor 143 illustrated in FIG. 2, but the channel region and the source / drain region of the first thin film transistor 142 are formed at different cross-sectional positions. A semiconductor film is also formed. That is, in the manufacturing process shown in FIGS. 3 to 5, two types of transistors 142 and 143 are formed at the same time. However, since they are manufactured in the same procedure, only the second thin film transistor 143 will be described in the following description. The description of the first thin film transistor 142 is omitted.

Next, as shown in FIG. 3C, a conductive film made of a metal film such as aluminum, tantalum, molybdenum, titanium, or tungsten is formed by sputtering, and then patterned to form a gate electrode 143A.
Next, high-concentration phosphorus ions are implanted in this state, and source / drain regions 143a and 143b are formed in the semiconductor film 210 in a self-aligned manner with respect to the gate electrode 143A. Note that a portion where impurities are not introduced becomes a channel region 143c.

Next, as illustrated in FIG. 3D, after forming the interlayer insulating film 230, contact holes 232 and 234 are formed, and the relay electrodes 236 and 238 are embedded in the contact holes 232 and 234.
Next, as illustrated in FIG. 3E, the signal line 132, the common power supply line 133, and the scanning line (not illustrated in FIG. 3) are formed on the interlayer insulating film 230. Here, the relay electrode 238 and each wiring may be formed in the same process.

Then, an interlayer insulating film 240 is formed so as to cover the upper surface of each wiring, and a contact hole (not shown) is formed at a position corresponding to the relay electrode 236. For example, aluminum is embedded in the contact hole. A reflective film made of a metal such as is formed by vapor deposition or the like. Then, an ITO (indium tin oxide) film is formed thereon, and the reflective film and the ITO film are patterned and surrounded by a signal line 132, a common power supply line 133, and a scanning line (not shown). A pixel electrode 141 electrically connected to the source / drain region 143a is formed at a predetermined position. The pixel electrode 141 functions as an anode, and is composed of a transparent electrode 141a made of ITO and a reflective electrode 141b made of aluminum or the like.
Here, the transparent electrode 141a made of ITO is used on the surface side of the pixel electrode 141 because the ITO has sufficient holes for the hole injection layer or the hole transport layer formed thereon. This is because the material is at an energy level that can be supplied. In addition, a portion sandwiched between the signal line 132, the common power supply line 133, and further the scanning line (not shown) is a place for forming a hole injection layer (or a hole transport layer) or a light emitting layer as described later. ing.

  Next, as shown in FIG. 4A, a partition wall 150 is formed so as to surround the formation place. The partition wall 150 functions as a partition member, and is formed, for example, by forming a photosensitive insulating organic material such as polyimide and curing (baking) after exposure and development. About the film thickness of the partition 150, it forms so that it may become the height of 1-2 micrometers, for example. By such a partition 150, a sufficient height is provided between the formation site of the hole injection layer (or hole transport layer) and the light emitting layer, that is, between the application position of these forming materials and the surrounding partition 150. A step 111 is formed.

  Next, a conductive material made of a metal such as aluminum is formed by vapor deposition or the like so as to cover the upper surface of the formed partition wall 150, and then this conductive film is patterned using, for example, a photolithography technique and an etching technique. As shown in FIG. 4B, a conductive portion 151 is formed on the partition wall 150 to obtain an example of the active matrix substrate of the present invention. Here, as a conductive material for forming the conductive portion 151, a material having higher conductivity than a material for forming a counter electrode described later is used. In addition, in this example, the conductive portion 151 is formed in a lattice shape along the shape of the partition 150 in a plan view (planar shape of the partition 150). However, the present invention is not limited to this, and may be formed in a stripe shape, for example.

Next, as shown in FIG. 4C, the hole injection layer forming material is coated from the inkjet head 10 by the inkjet head method with the upper surface of the substrate 121 facing upward, and the coating position surrounded by the partition wall 150. Apply selectively.
Here, as shown in FIG. 6A, the inkjet head 10 includes a nozzle plate 12 made of, for example, stainless steel and a vibration plate 13, and both are joined via a partition member (reservoir plate) 14. A plurality of spaces 15 and a liquid reservoir 16 are formed between the nozzle plate 12 and the diaphragm 13 by the partition member 14. Each space 15 and the liquid reservoir 16 are filled with ink, and each space 15 and the liquid reservoir 16 communicate with each other via a supply port 17. A plurality of nozzle holes 18 for ejecting ink from the space 15 are formed in the nozzle plate 12 in a line. On the other hand, a hole 19 for supplying ink to the liquid reservoir 16 is formed in the vibration plate 13.

Further, a piezoelectric element (piezo element) 20 is joined to the surface of the diaphragm 13 opposite to the surface facing the space 15 as shown in FIG. The piezoelectric element 20 is positioned between a pair of electrodes 21 and is configured to bend so that when it is energized, it projects outward. The diaphragm 13 to which the piezoelectric element 20 is bonded in such a configuration is bent integrally with the piezoelectric element 20 at the same time so that the volume of the space 15 is increased. It is going to increase. Therefore, ink corresponding to the increased volume in the space 15 flows from the liquid reservoir 16 through the supply port 17. Further, when energization to the piezoelectric element 20 is released from such a state, both the piezoelectric element 20 and the diaphragm 13 return to their original shapes. Accordingly, since the space 15 also returns to its original volume, the pressure of the ink inside the space 15 rises, and the ink droplet 22 is ejected from the nozzle hole 18 toward the substrate.
In addition, as an ink jet system of the ink jet head 10, a known system other than the piezo jet type using the piezoelectric element 20 may be employed.

Using the inkjet head 10 having such a configuration, in this example, as shown in FIG. 4C, a material for forming a hole injection layer is applied as an ink in the partition 150.
As a material for forming the hole injection layer, polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane, tris (8-hydroxyquinolinol) ) Aluminum and the like. In addition, instead of the hole injection layer, a hole transport layer may be formed. In that case, examples of the material for forming the hole transport layer include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine. Derivatives and the like are used. In addition, as a material for forming the hole injection layer or the hole transport layer, a polymer material such as polyethylene dioxythiophene or a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid can be used.
When the forming material 11A is applied using the ink jet head 10 in this manner, the liquid forming material 114A has high fluidity, and thus tends to spread in the horizontal direction, but the partition wall 150 is formed surrounding the applied position. As a result, it is possible to prevent the partition wall 150 from being spread outside.

Next, as shown in FIG. 5A, the solvent in the liquid forming material 114 </ b> A is evaporated by heating or light irradiation, and a solid hole injection layer (or hole transport layer) 140 </ b> A is formed on the pixel electrode 141. Form.
Next, in the same manner as in the formation of the hole injection layer (or hole transport layer) 140A, the material for forming the light emitting layer (light emitting material) is used as the ink from the inkjet head 10 as the hole injection layer (or (Hole transport layer) 140A is selectively applied.

As a material for forming the light emitting layer, for example, a material containing a precursor of a conjugated polymer organic compound and a fluorescent dye for changing the light emitting characteristics of the light emitting layer to be obtained is preferably used.
The precursor of the conjugated polymer organic compound is ejected from the inkjet head 10 together with a fluorescent dye or the like and formed into a thin film, and then, for example, is heated and cured as shown in the following formula (I), thereby conjugated polymer This refers to a material capable of generating a light emitting layer to be an organic EL layer. For example, in the case of a sulfonium salt of a precursor, a sulfonium group is eliminated by heat treatment and becomes a conjugated polymer organic compound.

  Such a conjugated polymer organic compound is solid and has strong fluorescence, and can form a homogeneous solid ultrathin film. Moreover, since the precursor of such a compound forms a strong conjugated polymer film after curing, the precursor solution is adjusted to a desired viscosity applicable to inkjet patterning described later before heat curing. It is possible to form a film under optimum conditions in a simple and short time.

  As such a precursor, for example, a precursor of PPV (poly (para-phenylene vinylene)) or a derivative thereof is preferable. A precursor of PPV or a derivative thereof is soluble in water or an organic solvent, and can be polymerized, so that a high-quality thin film can be obtained optically. Furthermore, since PPV has strong fluorescence and is also a conductive polymer in which double bond π electrons are non-polarized on the polymer chain, a high-performance organic EL device can be obtained.

  Examples of precursors of such PPV or PPV derivatives include PPV (poly (para-phenylene vinylene)) precursors, MO-PPV (poly (2,5-dimethoxy-1,4), as shown in chemical formula (II), for example. -Phenylene vinylene)) precursor, CN-PPV (poly (2,5-bishexyloxy-1,4-phenylene- (1-cyanovinylene))) precursor, MEH-PPV (poly [2-methoxy-5- (2′-ethylhexyloxy)]-para-phenylene vinylene) precursor and the like.

  The precursor of the PPV or PPV derivative is soluble in water as described above, and is polymerized by heating after film formation to form a PPV layer. The content of the precursor typified by the PPV precursor is preferably 0.01 to 10.0 wt%, more preferably 0.1 to 5.0 wt% with respect to the entire composition. If the amount of the precursor added is too small, it is insufficient to form a conjugated polymer film. If the amount is too large, the composition has a high viscosity and may not be suitable for high-accuracy patterning by the ink jet method.

  Furthermore, it is preferable that the light emitting layer forming material contains at least one fluorescent dye. Thereby, the light emission characteristics of the light emitting layer can be changed. For example, it is effective as a means for improving the light emission efficiency of the light emitting layer or changing the light absorption maximum wavelength (light emission color). That is, the fluorescent dye can be used not only as a light emitting layer material but also as a dye material having a light emitting function itself. For example, most of the exciton energy generated by carrier recombination on the conjugated macromolecular organic compound molecule can be transferred onto the fluorescent dye molecule. In this case, since light emission occurs only from fluorescent dye molecules having high fluorescence quantum efficiency, the current quantum efficiency of the light emitting layer is also increased. Therefore, by adding a fluorescent dye to the material for forming the light emitting layer, the emission spectrum of the light emitting layer simultaneously becomes that of the fluorescent molecule, which is effective as a means for changing the emission color.

The current quantum efficiency here is a scale for considering the light emission performance based on the light emission function, and is defined by the following equation.
ηE = energy of emitted photons / input electric energy And, by converting the light absorption maximum wavelength by doping the fluorescent dye, it is possible to emit, for example, three primary colors of red, blue, and green, thereby obtaining a full-color display body. It becomes possible.
Furthermore, the luminous efficiency of the EL element can be greatly improved by doping with a fluorescent dye.

  As the fluorescent dye, when forming a light emitting layer that emits red colored light, it is preferable to use rhodamine or a rhodamine derivative having red colored light. These fluorescent dyes are compatible with PPV and can easily form a uniform and stable light emitting layer. Specific examples of such fluorescent dyes include rhodamine B, rhodamine B base, rhodamine 6G, rhodamine 101 perchlorate and the like, and a mixture of two or more thereof may be used.

  Moreover, when forming the light emitting layer which emits green colored light, it is preferable to use quinacridone and its derivatives having green colored light. These fluorescent dyes are also compatible with PPV and can easily form a light emitting layer.

  Furthermore, when forming a light emitting layer that emits blue colored light, it is preferable to use distyrylbiphenyl having a blue colored light and derivatives thereof. These fluorescent dyes are soluble in a water / alcohol mixed solution, and have good compatibility with PPV, so that it is easy to form a light emitting layer.

  In addition, examples of other fluorescent dyes having blue colored light include coumarin and derivatives thereof. These fluorescent dyes are compatible with PPV and can easily form a light emitting layer. Specific examples of such fluorescent dyes include coumarin, coumarin-1, coumarin-6, coumarin-7, coumarin 120, coumarin 138, coumarin 152, coumarin 153, coumarin 311, coumarin 314, coumarin 334, coumarin 337, coumarin. 343 or the like.

Furthermore, examples of the fluorescent dye having a blue colored light include tetraphenylbutadiene (TPB) and TPB derivatives. These fluorescent dyes are compatible with PPV and can easily form a light emitting layer.
About the above fluorescent dye, only 1 type may be used for each color, and 2 or more types may be mixed and used for it.

  These fluorescent dyes are preferably added in an amount of 0.5 to 10 wt%, more preferably 1.0 to 5.0 wt%, based on the solid precursor of the conjugated polymer organic compound. If the amount of fluorescent dye added is too large, it will be difficult to maintain the weather resistance and durability of the light-emitting layer. On the other hand, if the amount added is too small, the effects of adding the fluorescent dye as described above cannot be obtained sufficiently. It is.

  The precursor and the fluorescent dye are preferably dissolved or dispersed in a polar solvent to form an ink, and this ink is preferably ejected from the inkjet head 10. The polar solvent can easily dissolve or uniformly disperse the precursor, luminescent dye, and the like, so that the solid component in the luminescent layer forming material in the nozzle hole 18 of the inkjet head 10 is attached or clogged. It can be prevented from waking up.

  Specific examples of such a polar solvent include water, alcohols compatible with water such as methanol and ethanol, N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethylimidazoline (DMI), An organic solvent or an inorganic solvent such as dimethyl sulfoxide (DMSO) may be used, and two or more of these solvents may be appropriately mixed.

Furthermore, it is preferable to add a wetting agent to the forming material. Thereby, it can prevent effectively that a forming material dries and solidifies in the nozzle hole 18 of the inkjet head 10. FIG. Examples of the wetting agent include polyhydric alcohols such as glycerin and diethylene glycol, and a mixture of two or more of these may be used. The amount of the wetting agent added is preferably about 5 to 20 wt% with respect to the total amount of the forming material.
In addition, you may add another additive and a film stabilization material, For example, a stabilizer, a viscosity modifier, an anti-aging agent, a pH adjuster, an antiseptic | preservative, a resin emulsion, a leveling agent etc. can be used.

When such a light emitting layer forming material is discharged from the nozzle hole 18 of the inkjet head 10, this forming material is applied onto the hole injection layer 140 </ b> A in the partition 150.
Here, the formation of the light emitting layer by discharging the forming material includes the formation material of the light emitting layer that emits red colored light, the material of the light emitting layer that emits green colored light, and the light emitting layer that emits blue colored light. The forming material is discharged and applied to the corresponding pixel 1A. The pixels 1A corresponding to the respective colors are determined in advance so that they are regularly arranged.

When the light emitting layer forming material of each color is discharged and applied in this way, the solvent in the light emitting layer forming material is evaporated, thereby forming a solid light emitting layer 140B on the hole injection layer 140A as shown in FIG. 5B. As a result, the light emitting portion 140 composed of the hole injection layer 140A and the light emitting layer 140B, that is, the laminate in the present invention is obtained. Here, with respect to the evaporation of the solvent in the light emitting layer forming material 114B, treatment such as heating or decompression is performed as necessary. However, the light emitting layer forming material usually has good drying properties and is quick drying. Accordingly, the light emitting layer 140B of each color can be formed in the order of application by sequentially discharging and applying the light emitting layer forming material of each color without performing such processing.
In this example, the light-emitting portion 140 to be a laminate is formed of the hole injection layer 140A (or hole transport layer) and the light-emitting layer 140B, but an electron transport layer is further formed on the light-emitting layer 140B. A layer structure may be used.

Thereafter, as shown in FIG. 5C, a transparent conductive material is formed on the entire surface of the substrate 121 by vapor deposition or the like, and the counter electrode 154 functioning as a cathode is formed in contact with the conductive portion 151. The transparent conductive material is not particularly limited, and various materials can be used. For example, calcium is used. In addition, when using calcium, when ensuring transparency, it is preferable to form this in the thin film about several tens of nm thick. Moreover, when calcium is formed in a thin film in this way, it is preferable to form a protective film (not shown) with a material such as aluminum or gold thereon. As for the aluminum or gold used as the protective film, it is necessary to make the thickness sufficiently thin so as not to impair the transparency, for example, about several tens of nm. In addition, the protective film may be a composite film formed by stacking a plurality of materials instead of a single material.
Further, the counter electrode 154 is sealed with a known sealing material to obtain a display which is an embodiment of the electro-optical device of the invention.

  Thus, in the electro-optical device (display 1) of this example, the conductive portion 151 made of a material (for example, aluminum) having higher conductivity than the counter electrode 154 made of, for example, calcium is provided on the partition wall 150. Since it is provided in contact with 154, the resistance of the counter electrode combined with the conductive portion 151 and the counter electrode 154 decreases, and the current to the end of the wiring becomes uniform, thereby increasing the size of the display 1 (large screen). High definition).

In addition, since the hole injection layer (or hole transport layer) 140A is provided, the light emission layer 140B can have high light emission capability due to the hole injection layer (or hole transport layer) 140A, and thus more favorable. Light emission characteristics can be obtained.
Further, since the pixel electrode 141 is composed of a transparent electrode 141a made of ITO and a reflective electrode 141b formed on the substrate (TFT substrate) 121 side, the light from the light emitting layer 140B is reflected by the reflective electrode 141b. By doing so, the amount of light emitted to the side opposite to the substrate 121 can be increased. Further, by forming the reflective electrode 141b with a metal, the resistance of the entire pixel electrode 141 can be lowered even though the transparent electrode 141a is formed of ITO having a relatively high resistance. In addition, since the transparent electrode 141a is formed of ITO at an energy level that can sufficiently supply holes to the hole injection layer (or hole transport layer) 140A, the hole injection layer (or hole transport) is formed. Layer) 140A can be enhanced to improve the light emission characteristics of the light emitting layer 140B.

  In the active matrix substrate for forming the electro-optical device, since the conductive portion 151 is provided on the partition wall 150 as described above, the conductive portion 151 and the counter electrode 154 are combined substantially. The resistance of the electrode is lowered, and the current to the end of the wiring is made uniform, whereby the electro-optical device (display 1) using this can be increased in size (larger screen) and higher in definition.

  In the method of manufacturing the electro-optical device, the pixel electrode 141, the partition wall 150 that separates the pixels and the conductive portion 151 on the partition wall 150 are formed on the substrate 121, and then holes are injected into the partition wall 150. Since the layer (or hole transport layer) 140A and the light emitting layer 140B are formed, the conductive portion 151 is not affected without affecting the hole injection layer (or hole transport layer) 140A or the light emitting layer 140B made of an organic material. The formation process can be performed.

  In addition, since the material for forming the hole injection layer (or hole transport layer) 140A and the light emitting layer 140B is applied to the partition wall 150 by an inkjet method, these materials are selectively discharged and applied to the partition wall 150. Therefore, a full color display organic EL device can be easily manufactured by arranging materials corresponding to each color of red, green, and blue as the light emitting layer material.

The organic EL element and the manufacturing method thereof according to the present invention are not limited to the above example. For example, as shown in FIG. 7, a recess 150a is formed on the upper surface of the partition wall 150, and a conductive portion is formed in the recess 150a. The conductive portion 151 may be formed by applying a material by an inkjet method.
That is, when the partition 150 is formed, a resist pattern (not shown) is formed on the upper surface of the partition 150 along the shape of the partition 150 so that a recess is formed in the center thereof, and etching is performed using the resist pattern. As a result, a recess 150a is formed on the partition 150 as shown in FIG. And the conductive part 151 is formed by apply | coating the material of the conductive part 151 in this recessed part 150a with the inkjet method.

As a conductive material that can be applied by such an ink jet method, for example, a silver colloid dispersion or a gold colloid dispersion can be used. Such a colloidal liquid is ejected from the ink jet head 10 shown in FIGS. 6A and 6B, applied to the recess 150a, and then subjected to a treatment such as heating, as shown in FIG. The conductive portion 151 can be formed on the substrate.
When the conductive portion 151 is formed in this way, it is possible to prevent a problem that the conductive material flows down from the upper surface of the partition wall 150 to reach the partition wall 150 and is electrically connected to the pixel electrode 141.

In addition, for the formation of the conductive portion 151, a dove dipping method may be employed instead of the ink jet method. That is, after the partition 150 is formed as shown in FIG. 4A, the upper surface of the partition is subjected to lyophilic treatment and the side surface thereof is subjected to lyophobic treatment. Then, the upper surface portion of the partition wall 150 is immersed in a conductive material prepared in a liquid state (for example, the silver colloid dispersion liquid or the gold colloid dispersion liquid), and the conductive material is attached to the upper surface of the partition wall 150. Thereafter, the conductive material is cured by heat treatment or the like to form a conductive portion 151. Here, in order to develop liquid repellency on the side surface of the partition wall 150, for example, a fluorine-based compound such as CF ₄ , SF ₅ , or CHF ₃ is applied to the surface (side surface) of the partition wall 150, and this is further subjected to plasma treatment. Such a method is adopted. Further, in order to develop lyophilicity on the upper surface of the partition wall 150, a method of performing UV irradiation treatment on the surface (upper surface) that has been subjected to liquid repellency treatment first is employed.

  After the lyophilic treatment is performed on the upper surface of the partition wall 150 and the side surfaces are subjected to a liquid repellent treatment, the upper surface portion of the partition wall 150 is immersed in a conductive material prepared in a liquid state. It adheres selectively only to the upper surface without adhering to the surface. Therefore, the conductive portion can be formed on the partition relatively easily by such treatment.

The conductive portion 151 may be formed at any time as long as it is performed prior to the formation of the hole injection layer (or hole transport layer) or the light emitting layer. The material for forming the portion may be continuously formed, and then these films may be etched using the same resist pattern to form the conductive portion 151 and the partition wall 150. Alternatively, the conductive portion previously formed may be formed. The partition wall 150 may be formed by etching a film made of the partition wall forming material using 151 as a mask and patterning the film.
If the conductive portion 151 and the partition wall 150 are formed in this manner, when patterning is performed by a photolithography process, the photolithography process is not performed separately for the partition wall formation and the formation of the conductive portion. Therefore, the process can be simplified.

  Prior to the formation of the pixel electrode 141, the partition wall 150 is formed. From this state, for example, aluminum is formed on the entire surface, and then this aluminum film is patterned, whereby the reflective electrode 141 a in the pixel electrode 141 is electrically conductive. The portion 151 may be formed at the same time.

  In the embodiment, the pixel electrode 141 functions as an anode and the counter electrode 154 functions as a cathode. Conversely, the pixel electrode 141 functions as a cathode and the counter electrode 154 functions as an anode. It can also be configured. In that case, the hole injection layer (or hole transport layer) 140A is provided on the electrode side that functions as the anode, that is, on the counter electrode side. In the case of such a configuration, for example, an electrode made of calcium or the like is disposed on the inner surface side (light emitting layer side) of the pixel electrode 141, and aluminum or the like that also functions as a protective film on the outer side (substrate side). The reflective electrode may be formed, and the counter electrode 154 may be formed of ITO, which is a transparent conductive material.

In addition, the electro-optical device of the present invention may be configured as shown in FIGS. 8A and 8B, for example, instead of the configuration shown in FIGS. 2A and 2B. The electro-optical device shown in FIGS. 8A and 8B is different from that shown in FIGS. 2A and 2B mainly in the first thin film transistor (not shown) and the second thin film transistor. The planarization film 180 is formed on the planarization film 143, and the pixel electrode 141 is disposed on the planarization film 180.
That is, a planarization film 180 is formed on the second thin film transistor 143 through an interlayer insulating film (not shown), and a partition wall 150 and a pixel electrode 141 are formed on the planarization film 180. Hereinafter, FIG. Each component is formed in the same manner as in the example shown in b). In FIG. 8A, reference numeral 182 denotes a relay electrode formed in the planarizing film 180.

With this configuration, the pixel electrode 141 can be formed without being affected by the thin film transistor 143, and in particular, by forming and arranging the pixel electrode 141 on the planarization film 180, the design rule is satisfied. The pixel electrode 141 can be enlarged to the limit.
In the example shown in FIGS. 8A and 8B, the pixel electrode 141 may function as an anode and the counter electrode 154 may function as a cathode. Conversely, the pixel electrode 141 may function as a cathode and a counter electrode. 154 may be configured to function as an anode. In that case, as in the previous example, the hole injection layer (or hole transport layer) 140A is provided on the electrode side that functions as the anode, that is, on the counter electrode side.

  In the embodiment, the light emitted from the light emitting layer is configured to be extracted from the side opposite to the substrate, that is, through the counter electrode. In such a case, in order to improve the light extraction efficiency. The pixel electrode is preferably provided on the planarization film. Of course, the present invention is not limited to this, and may be configured to be taken out via the pixel electrode side. In that case, although it is necessary to use transparent substrates and pixel electrodes, respectively, non-transparent electrodes can be used as the counter electrode.

Next, a specific example of an electronic apparatus provided with the electro-optical device serving as the display of the above example will be described.
FIG. 9A is a perspective view showing an example of a mobile phone. 9A, reference numeral 500 denotes a cellular phone body, and reference numeral 501 denotes an EL display unit (display means) including the display (electro-optical device) shown in FIG. 1, FIG. 2, or FIG.
FIG. 9B is a perspective view illustrating an example of a portable information processing apparatus such as a word processor or a personal computer. 9B, 600 is an information processing apparatus, 601 is an input unit such as a keyboard, 603 is an information processing body, 602 is the display (electro-optical apparatus) shown in FIG. 1, FIG. 2, or FIG. An EL display unit (display means) provided is shown.
FIG. 9C is a perspective view showing an example of a wristwatch type electronic device. 9C, reference numeral 700 denotes a watch body, and reference numeral 701 denotes an EL display unit (display means) including the display (electro-optical device) shown in FIG. 1, FIG. 2, or FIG. .
Since the electronic apparatus shown in FIGS. 9A to 9C is provided with the display (electro-optical device), it is an electronic apparatus provided with display means capable of obtaining excellent display quality.
For an electro-optical device used in an electronic apparatus, it is preferable to provide an antireflection film composed of, for example, a polarizing plate and a (λ / 4) plate on the light exit side. It is possible to prevent the display performance from being deteriorated due to the reflection at the conductive portion 151 formed on the substrate.

  As described above, since the active matrix substrate of the present invention has a conductive material disposed on the partition walls, for example, it is formed separately from the counter electrode and provided in a state of being connected to the counter electrode. Thus, the substantial resistance of the counter electrode in which the conductive material is combined with the counter electrode can be reduced, and thereby the current to the end of the wiring can be made uniform.

  Since the electro-optical device according to the present invention has the conductive portion disposed on the partition wall, the resistance of the substantial counter electrode in which the conductive portion is combined with the counter electrode is reduced, and thereby the current is uniformized to the end of the wiring. Is intended. Therefore, by making the current uniform in this way, it is possible to increase the size (large screen) and high definition of a display including this organic EL element.

  Since the electro-optical device manufacturing method of the present invention is a method of forming a light emitting layer after forming a conductive portion, the conductive portion forming process can be performed without affecting the light emitting layer. In addition, since the resistance of the counter electrode can be substantially reduced by forming the conductive portion, it is possible to equalize the current to the end of the wiring, for example, to increase the size of the display as an electro-optical device (large screen) ), High definition can be achieved.

  Since the electronic device of the present invention uses an electro-optical device in which the resistance of the counter electrode is substantially reduced due to the formation of the conductive portion on the partition wall, the current to the end of the wiring is made uniform. By being able to do so, it becomes possible to increase its size (large screen) and high definition.

It is a circuit diagram which shows the arrangement | positioning part of the display of this invention. (A) is an enlarged plan view showing a planar structure of the pixel portion, and (b) is a cross-sectional view taken along line AA in (a). (A)-(e) is principal part side sectional drawing for demonstrating the manufacturing method of the organic EL element of this invention to process order. (A)-(c) is principal part sectional drawing for demonstrating the process following FIG. 3 in order. (A)-(c) is principal part sectional drawing for demonstrating the process following FIG. 4 in order. It is a figure for demonstrating schematic structure of an inkjet head, (a) is a principal part perspective view, (b) is a principal part sectional side view. It is principal part sectional drawing for demonstrating another manufacturing example about a partition and an electroconductive part. (A) is an enlarged plan view showing a planar structure of the pixel portion, and (b) is a cross-sectional view of the main part of (a). It is a figure which shows the specific example of the electronic device provided with the display, (a) is a perspective view which shows an example at the time of applying to a mobile telephone, (b) is a perspective view which shows an example at the time of applying to an information processing apparatus. (C) is a perspective view which shows an example at the time of applying to a wristwatch-type electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display, 1A ... Pixel, 10 ... Inkjet head, 121 ... Substrate (TFT substrate), 140 ... Light emitting part (laminate), 140A ... Hole injection layer (or hole transport layer), 140B ... Light emitting layer, 141 ... pixel electrode, 150 ... partition wall, recess, 150a, 151 ... conductive part, 154 ... counter electrode.

Claims (5)

A stacked body including a plurality of pixel electrodes separated by a partition made of an insulating material on a substrate having an active element, a light emitting layer disposed on the pixel electrode, and a counter electrode disposed on the stacked body A method of manufacturing an electro-optical device comprising:
Forming a partition wall separating the pixel electrode and the pixel on the substrate;
Forming a conductive portion connected to the counter electrode on the partition;
Forming a light emitting layer in a region partitioned by the partition wall by applying a material of the light emitting layer by an inkjet method ,
The upper surface of the partition wall is subjected to lyophilic treatment and the side surface is subjected to lyophobic treatment, and the upper surface portion of the partition wall is immersed in a liquid material of the conductive portion so that the conductive material adheres to the upper surface of the partition wall. A method of manufacturing an electro-optical device, wherein the material is cured to form the conductive portion . A stacked body including a plurality of pixel electrodes separated by a partition made of an insulating material on a substrate having an active element, a light emitting layer disposed on the pixel electrode, and a counter electrode disposed on the stacked body A method of manufacturing an electro-optical device comprising:
Forming a partition wall separating the pixel electrode and the pixel on the substrate;
Forming a conductive portion connected to the counter electrode on the partition;
Forming a light emitting layer in a region partitioned by the partition wall by applying a material of the light emitting layer by an inkjet method,
When forming the partition wall and the conductive portion on the partition wall, a partition wall forming material is formed, and then a conductive material is formed on the film made of the partition wall forming material, and then the film made of the conductive material is patterned. And forming a partition wall by patterning a film made of a partition wall forming material using the obtained conductive section as a mask, and forming a partition wall . By injecting a hole injection layer or a hole transport layer material to the electrode functioning as the anode of the pixel electrode and the counter electrode with respect to the position to be the light emitting layer by an inkjet method, hole injection is performed. the method of manufacturing an electro-optical device according to claim 1 or 2, characterized in that a layer or a hole transport layer. An electronic device formed by using an electro-optical device obtained by the manufacturing method according to any one of claims 1-3. The electronic apparatus according to claim 4, wherein an antireflection film is provided on a light emitting side of the electro-optical device.

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