JP2011025189A - Coating apparatus and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To successfully carry out the application of a liquid. <P>SOLUTION: In the coating apparatus 100, the transmittance of a liquid 120 in a nozzle head 106 is detected by a transmittance detecting part 60 provided on the nozzle head 106 and the size and the quantity of bubbles stagnating in the nozzle head 106 are determined based on the value of the light transmittance. Further in the coating apparatus 100, because the bubbles stagnating in the nozzle head 106 are removed by moving the nozzle head 106 to a waiting position before the discharge of the liquid 120 from the nozzle head 106 is made impossible after the value of light transmittance detected by the transmittance detecting part 60 exceeds a first permissible value or a second permissible value, a trouble that the application of the liquid 120 is interrupted because the bubbles are excessively accumulated in the nozzle head 106 is suppressed to enable suitable application of the liquid 120. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating apparatus and a coating method.

Conventionally, in the step of forming a carrier transport layer in the manufacturing process of an EL element used in an EL (Electro Luminescence) panel, a groove between partition walls formed so as to surround a transparent electrode (anode) provided on a glass substrate In addition, a technique of a nozzle printing method in which an EL material liquid is poured through a nozzle and applied (for example, see Patent Document 1).
Then, an EL element is manufactured by providing a counter electrode (cathode) on the carrier transport layer formed by drying the applied EL material liquid, and the applied area where the EL material liquid is applied is light emission of the EL panel. It becomes an area.

JP 2002-75640 A

However, in the case of the above-mentioned Patent Document 1, in the EL panel manufacturing apparatus, in the process in which the application of the EL material liquid, which is a liquid, is continuously performed, the liquid is sent by collecting bubbles in the liquid sent by the pump. May stay in the path.
In addition, there is a problem in that it may be difficult to discharge liquid from the nozzle because bubbles exceeding the allowable amount stay in the nozzle head having the nozzle.

  Therefore, an object of the present invention is to satisfactorily apply a liquid.

In order to solve the above problems, one aspect of the present invention is a coating apparatus,
A liquid reservoir in which liquid is stored;
A discharge section having a nozzle for discharging the liquid;
A supply pipe piped from the liquid storage part to the discharge part;
A nozzle moving unit that moves the discharge unit relative to an object to which the liquid is applied;
A transmittance detector for detecting the light transmittance of the space in which the liquid accumulates in the ejection part; a controller for controlling the nozzle moving part and the transmittance detector;
With
When the control unit determines that the light transmittance detected by the transmittance detection unit exceeds an allowable value, the control unit causes the nozzle moving unit to move the ejection unit to a standby position, and It is characterized by executing a process of removing bubbles remaining in the section.
Preferably, the control unit corresponds to a timing when the light transmittance exceeds the allowable value based on the light transmittance detected by the transmittance detection unit and the liquid cannot be ejected from the nozzle. Until the light transmittance threshold value is reached, the discharge unit is moved to the standby position, and a process of removing bubbles remaining in the discharge unit is executed.
Preferably, the standby position is provided with a defoaming section that sucks and removes bubbles in the discharge section.
Preferably, the transmittance detector is
The projector includes a projector that emits predetermined light toward the space in the ejection unit, and a light receiver that detects the light that has passed through the space.
Preferably, the nozzle moving unit is configured to discharge the ink over a range in which a plurality of application target areas where the liquid is to be applied and non-target areas where the liquid is not applied are alternately arranged. Moving the part, applying the liquid continuously discharged from the nozzle to the object,
The control unit predicts a timing at which the light transmittance detected by the transmittance detection unit becomes the threshold, and determines that the ejection unit is at a position corresponding to the application target region at the predicted timing. In such a case, in the non-target region before the application target region, a process of moving the discharge unit to the standby position and removing bubbles remaining in the discharge unit is executed.

Another aspect of the present invention is a coating method,
The liquid is supplied from a liquid storage part in which the liquid is stored via a supply pipe, and a discharge part having a nozzle for discharging the liquid is moved relative to the object, and the liquid is applied to the object. Apply,
While applying the liquid to the object, the light transmittance of the space in which the liquid is accumulated in the ejection unit is detected, and whether or not the light transmittance exceeds an allowable value. Judgment
When it is determined that the light transmittance exceeds an allowable value, the ejection unit is moved to a standby position, and a defoaming process is performed to remove bubbles remaining in the ejection unit.
Preferably, in the operation of performing the defoaming process, when it is determined that the light transmittance exceeds the allowable value, the light transmittance reaches a threshold value when the coating operation is continued, and the nozzle performs the operation from the nozzle. The timing at which the liquid cannot be ejected is predicted, and the ejection section is moved to the standby position until the timing is reached.

  According to the present invention, it is possible to satisfactorily apply liquid.

It is a schematic surface which shows a coating device. It is sectional drawing which shows a nozzle head. It is sectional drawing which shows defoaming parts, such as a sealing cap of a standby position. It is explanatory drawing which shows an example of the bubble which retains in a nozzle head. It is explanatory drawing which shows an example of the bubble which retains in a nozzle head. It is a graph which shows an example of time and light transmittance. It is explanatory drawing which shows the application pattern of the liquid accompanying the movement of the nozzle head of a coating device. It is sectional drawing which shows the modification of a nozzle head. It is a top view which shows the arrangement configuration of the pixel of an EL panel. It is a top view which shows schematic structure of EL panel. It is a circuit diagram showing a circuit corresponding to one pixel of an EL panel. It is the top view which showed 1 pixel of EL panel. It is arrow sectional drawing of the surface along the XIII-XIII line | wire of FIG. It is sectional drawing which shows the pixel electrode exposed between the banks of EL panel. It is a front view which shows an example of the mobile telephone by which EL panel was applied to the display panel. They are the front side perspective view (a) which shows an example of the digital camera with which the EL panel was applied to the display panel, and a rear side perspective view (b). It is a perspective view which shows an example of the personal computer by which EL panel was applied to the display panel.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

[1] Configuration of coating device The coating device is, for example, an organic layer of an organic electroluminescence display panel that is a light-emitting panel (for example, a hole injection layer, a light-emitting layer, an electron injection layer), an organic layer of an organic transistor, a liquid crystal display Organic color development layer of color filter (for example, RGB color development layer including organic material, black matrix including organic material), organic conductive layer of various electronic devices (for example, conductive wiring including organic material), other organic layers, Alternatively, it is used for forming a functional layer containing a material in which an inorganic material such as metal fine particles is dispersed or dissolved in a solution.

  As shown in FIG. 1, the coating apparatus 100 includes a liquid tank 108 serving as a liquid storage unit that stores a liquid 120, a nozzle head 106 that is a discharge unit having a nozzle 168 that discharges the liquid 120, and a liquid tank 108. A supply pipe 107 piped up to the nozzle head 106, a feeder 116 for sending the liquid 120 in the liquid tank 108 to the nozzle head 106 through the supply pipe 107, and a nozzle for an object (substrate 121) to which the liquid 120 is applied. A carriage 105 and a moving device 102 as a nozzle moving unit that relatively moves the head 106; an optical sensor unit 60 that is a transmittance detecting unit that detects a light transmittance of a space in which the liquid 120 is accumulated in the nozzle head 106; A control unit 119 for controlling each unit of the apparatus is provided.

As shown in FIG. 1, a work table 101 is mounted on a moving device 102, and a substrate 121 as an object is placed on the work table 101.
The moving device 102 moves the work table 101 and the substrate 121 placed thereon in a linear direction. For example, the moving device 102 includes a rail that guides the work table 101 and a drive mechanism that drives the work table 101 along the rail.
The moving device 102 is controlled by the control unit 119. The control unit 119 drives the moving device 102 intermittently, and the moving device 102 moves the work table 101 and the substrate 121 intermittently. That is, the moving device 102 operates to repeat the movement and stop of the work table 101 and the substrate 121 under the control of the control unit 119.
The moving direction of the work table 101 is a sub-scanning direction.

Above the work table 101, a rail 103 serving as a guide is supported by a machine frame 104. The rail 103 is provided in a direction orthogonal to the moving direction of the work table 101 when viewed from above. A carriage 105 is mounted on the rail 103, and a nozzle head 106 is mounted on the carriage 105. The carriage 105 and the nozzle head 106 are guided along the rail 103 and are movably provided along the rail 103.
The carriage 105 reciprocates the nozzle head 106 linearly in a direction orthogonal to the moving direction of the work table 101. For example, the carriage 105 incorporates a drive source such as a motor, and the carriage 105 moves along the rail 103 by the motor drive.
The carriage 105 is controlled by the control unit 119. The control unit 119 drives the carriage 105 in accordance with the intermittent stop of the moving device 102, and the carriage 105 moves while the moving device 102 is stopped.
The moving direction of the carriage 105 is a main scanning direction.

The nozzle head 106 is mounted on the carriage 105 so that the tip thereof faces downward.
As shown in FIG. 2, in the nozzle head 106, a supply pipe 107 is connected to an inlet 162 provided at the upper end of a substantially cylindrical nozzle head main body 161. A bottom surface 165 is provided at the lower end of the nozzle head main body 161, and an opening 166 is formed at the center of the bottom surface 165.
A space 163 in which the liquid 120 accumulates is formed inside the nozzle head main body 161, a nozzle plate 167 is disposed below the space 163, and the opening 166 is closed by the nozzle plate 167. A minute nozzle hole (nozzle) 168 is formed at the center of the nozzle plate 167 and at a position corresponding to the opening 166. The diameter of the nozzle hole 168 is 10 to 20 μm. The liquid 120 is discharged from the nozzle hole 168.
A filter 164 for removing particles in the liquid is disposed above the space 163 of the nozzle head main body 161.

In addition, a pair of transparent windows 60 a and 60 b having optical transparency are provided on the side surface of the nozzle head main body 161 at locations facing each other across the central portion of the space 163 in the nozzle head 106. As the transparent windows 60a and 60b, for example, glass plates that are a material resistant to the liquid 120 are used. It is desirable to provide a UV cut film on the transparent windows 60a and 60b to prevent the liquid 120 from being deteriorated by UV light.
A projector 61 that emits predetermined light toward the space 163 is provided outside the one transparent window 60a, and a light receiver 62 that detects light that has passed through the space 163 is provided outside the other transparent window 60b. . The light projector 61 and the light receiver 62 constitute an optical sensor unit 60.
The optical sensor unit 60 detects the light transmittance corresponding to the intensity of the light detected by the light receiver 62, detects the liquid 120 in the nozzle head 106 based on the detected light transmittance value, or detects the liquid 120. Detecting bubbles contained in or quantifying bubbles. The optical sensor unit 60 is controlled by the control unit 119.
The detection of the liquid 120 and the bubbles in the liquid 120 by the optical sensor unit 60 will be described later.

As the projector 61, an incandescent lamp, a fluorescent lamp, a halogen lamp, a tungsten lamp, a semiconductor laser, an LED, an organic EL, or the like can be used. In addition, the light from the projector 61 may be guided by an optical fiber, an optical waveguide, or the like and incident from the transparent window 60a. Further, the light from the projector 61 need not always be incident on the head 106, and may be incident intermittently by a shutter or the like.
As the light receiver 62, a photomultiplier tube, a photodiode, a phototransistor, or the like can be used. In addition, the light that has passed through the space 163 may be guided by an optical fiber, an optical waveguide, or the like to enter the light receiver 62. Further, it is desirable that the light receiver 62 detects transmitted light by monitoring the illuminance change of the projector 61 itself.
In addition, although it is preferable to select the wavelength of the light which the light projector 61 in the optical sensor part 60 outputs according to the absorption area of the liquid 120, it may be general-purpose white light.
Further, although the projector 61 and the light receiver 62 are provided outside the nozzle head 106, they may be provided inside the nozzle head 106. Further, instead of providing the transparent windows 60a and 60b in the nozzle head 106, two opposing insertion ports are provided in the side surface of the nozzle head 106, the projector 61 is fitted in one insertion port, and light is received in the other insertion port. A vessel 62 may be fitted. A transparent window may be provided over the entire circumference of the nozzle head 106. In addition, the optical sensor unit 60 is not limited to a configuration including a transmissive sensor, and may be configured to include a reflective sensor. That is, the light receiver 62 does not receive the light projected from the projector 61 and transmitted through the liquid 120, but the light receiver 62 receives the reflected light that is projected from the projector 61 and reflected by the liquid 120 in the nozzle head 106. It is good also as what receives light.

The supply pipe 107 is piped from the nozzle head 106 to the liquid tank 108, one end of the supply pipe 107 is connected to the nozzle head 106, and the other end of the supply pipe 107 is connected to the liquid tank 108.
As the supply pipe 107, a tube made of a material resistant to the liquid 120 stored in the liquid tank 108 is used. Specifically, the supply pipe 107 is a tube made of silicone resin. The inner diameter of the supply pipe 107 is 1 to 7 mm. The inner diameter of the supply pipe 107 may be uniform from the liquid tank 108 to the nozzle head 106 or may be non-uniform. For example, the inner diameter of the supply pipe 107 is large near the liquid tank 108 and small near the nozzle head 106.

A liquid 120 is stored in the liquid tank 108. Examples of the liquid 120 include an organic liquid, an aqueous type liquid, and an emulsion type liquid. The liquid 120 is appropriately selected according to the application of the coating apparatus 100.
The liquid tank 108 is provided with a supply device 116. The supply unit 116 sends out the liquid 120 in the liquid tank 108 to the nozzle head 106 through the supply pipe 107. More preferably, the supply unit 116 supplies the liquid 120 to the supply pipe 107 in a state where the pressure of the liquid 120 to be sent out is kept constant.
The supplier 116 is, for example, a pump, and specifically, a piston-type pump or a gas-type pump. The piston-type pressure feed pump has a movable piston housed in a syringe-like liquid tank 108, and the movable piston is pushed by a driving source such as a motor, an air cylinder, or a solenoid, so that the liquid 120 in the liquid tank 108 is discharged. It pushes out to the supply pipe 107. The gas pressure pump is a gas (mainly inert gas (for example, nitrogen gas)) that is fed into a sealed liquid tank 108 to pressurize the liquid surface in the liquid tank 108, and the liquid in the liquid tank 108. 120 is pushed out to the supply pipe 107. Of course, a pump other than the piston-type pump and the gas-type pump may be used for the feeder 116.
The feeder 116 is controlled by the control unit 119. The control unit 119 drives the supply device 116 in accordance with the movement of the carriage 105, and the supply device 116 performs a supply operation while the carriage 105 is moving.

A mass flow controller 109 is provided in the middle of the supply pipe 107. The mass flow controller 109 measures the flow rate of the liquid 120 flowing through the supply pipe 107 and controls the flow rate of the liquid 120 flowing through the supply pipe 107. The flow rate measured by the mass flow controller 109 is output to the control unit 119.
Further, the control unit 119 sets a flow rate by the mass flow controller 109 (hereinafter, the set flow rate is referred to as a set flow rate). The mass flow controller 109 performs constant flow control so as to maintain the flow rate of the liquid 120 flowing through the supply pipe 107 at the set flow rate.

A sealing cap 150 serving as a defoaming portion is disposed in the standby position of the nozzle head 106 in the vicinity of the work table 101 and below the rail 103.
As shown in FIG. 3, the defoaming unit includes a sealing cap 150, a drain pipe 151, a cooling trap 130, a suction pipe 152, and a vacuum pump 140 that is a decompression device. One end of the tube 151 is attached. By closing the lower end of the nozzle head 106 with the sealing cap 150, the nozzle hole 168 of the nozzle head 106 communicates with the drain pipe 151. The other end of the drain pipe 151 is connected to the cooling trap 130.
The cooling trap 130 includes an outer container 131, a refrigerant 133 in the outer container 131, a sealed container 132 that is accommodated inside the outer container 131 and immersed in the refrigerant 133, and the like. The other end of the drain pipe 151 is provided through the upper surface of the sealed container 132. Further, the other end of the suction pipe 152 having one end connected to the vacuum pump 140 is provided through the upper surface of the sealed container 132. In the sealed container 132, the end of the suction tube 152 is located higher than the end of the drain tube 151.
The carriage 105 is connected so that the nozzle head 106 is connected to the sealing cap 150 when the nozzle head 106 is in a standby state where the liquid 120 is not applied to the substrate 121 or when bubbles remaining in the nozzle head 106 are removed. As a result, the nozzle head 106 is moved to the sealing cap 150.
The vacuum pump 140 is operated and sucked in a state where the sealing cap 150 and the lower end of the nozzle head 106 are in close contact with each other, whereby the liquid 120 in the liquid tank 108 is drawn toward the nozzle head 106 side or dripped from the nozzle head 106. The liquid 120 to be received can be received by the cooling trap 130. Further, when the vacuum pump 140 performs suction, the bubbles staying in the nozzle head 106 can be sucked out and removed.

  Next, detection of bubbles in the liquid 120, which is detection of the liquid 120 by the optical sensor unit 60, will be described.

  The light receiver 62 of the optical sensor unit 60 described above photoelectrically converts the intensity of the received light into an electrical signal, and outputs a received light intensity signal representing the intensity of the received light to the control unit 119. The received light intensity detected by the light receiver 62 also represents the light transmittance of the liquid 120 in the nozzle head 106. That is, as the light transmittance of the liquid 120 in the nozzle head 106 increases, the received light intensity detected by the light receiver 62 also increases, so that the received light intensity and the light transmittance have a correlation. Thereby, not only the light reception intensity but also the light transmittance of the liquid 120 in the nozzle head 106 is quantified by the light receiver 62.

The received light intensity detected by the light receiver 62 quantifies the state of bubbles contained in the liquid 120 in the nozzle head 106. That is, if there are no bubbles in the liquid 120 in the nozzle head 106, the received light intensity detected by the light receiver 62 is substantially constant (for example, 40%; initial value) (see line c in the graph of FIG. 6). .
On the other hand, as shown in FIG. 4, when fine bubbles are generated in the liquid 120, light is irregularly reflected at the interface between the liquid 120 and the bubbles. For this reason, as the number of fine bubbles generated in the liquid 120 increases, the received light intensity (light transmittance) detected by the light receiver 62 decreases. This quantifies the number of bubbles in the liquid 120. For example, when the number of bubbles in the liquid 120 increases with time as indicated by a line a in the graph shown in FIG. 6, the received light intensity decreases with time.
Further, as shown in FIG. 5, when a large bubble is generated by combining bubbles generated in the liquid 120, light passes through the cavity of the bubble. Therefore, as the bubble size increases, the received light intensity (light transmittance) detected by the light receiver 62 increases. This quantifies the size of the bubbles in the liquid 120. For example, as shown by the line b in the graph shown in FIG. 6, when the size of the bubbles in the liquid 120 increases with time, the received light intensity increases with time.

  The control unit 119 has a function as a first comparator, and compares the light transmittance based on the level of the received light intensity signal input from the light receiver 62 with a predetermined first allowable value shown in FIG. The first allowable value is, for example, 60%, and is a value that partitions whether or not the size of bubbles generated in the liquid 120 existing in the nozzle head 106 is equal to or larger than a predetermined size. Therefore, when the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 62 exceeds the first allowable value and is equal to or higher than the first allowable value as a result of the comparison, It is determined that the size of the bubbles generated in the liquid 120 existing in is equal to or larger than a predetermined size. On the other hand, as a result of the comparison, when the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 62 is less than the first allowable value, the control unit 119 is generated in the liquid 120 existing in the nozzle head 106. It is determined that the bubble size is less than the predetermined size. Here, the predetermined size is a size that does not hinder the flow of the liquid 120. When the size of the bubbles contained in the liquid 120 in the nozzle head 106 becomes larger than the predetermined size, and the size of the bubbles corresponds to the first threshold shown in FIG. 6, the flow of the liquid 120 is hindered. .

When the control unit 119 determines that the light transmittance based on the received light intensity signal level detected by the optical sensor unit 60 has exceeded the first allowable value, the control unit 119 causes the carriage 105 of the nozzle moving unit to move the nozzle head. 106 is moved to the sealing cap 9 at the standby position, and a process of removing bubbles remaining in the nozzle head 106 is executed.
In particular, the control unit 119 is based on the light transmittance detected by the light sensor unit 60 and at a timing when the liquid 120 cannot be ejected from the nozzle head 106 after the light transmittance exceeds the first allowable value (60%). Until the corresponding first threshold value (for example, 80%) of the light transmittance is reached, the nozzle head 106 is moved to the standby position, and processing for removing bubbles remaining in the nozzle head 106 is executed. Specifically, the control unit 119 predicts the time until timing T at which the light transmittance detected by the optical sensor unit 60 becomes the first threshold (80%), and the control unit 119 operates the carriage 105 by that timing. Then, the nozzle head 106 is moved to the standby position, and a process of removing bubbles remaining in the nozzle head 106 is executed.
In addition, the nozzle head 106 is moved to the standby position by the timing T when the light transmittance detected by the optical sensor unit 60 becomes the first threshold (80%), and the bubbles staying in the nozzle head 106 are removed. The processing operation will be described later.

  Further, the control unit 119 has a function as a second comparator, and compares the light transmittance based on the level of the received light intensity signal input from the light receiver 62 with a predetermined second allowable value shown in FIG. The second allowable value is, for example, 30%, and is a value that partitions whether the number of bubbles generated in the liquid 120 existing in the nozzle head 106 is less than a predetermined number. This second tolerance value is lower than the first tolerance value. Therefore, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 62 does not reach the second allowable value and is greater than the second allowable value as a result of the comparison, the nozzle head 106 It is determined that the number of bubbles generated in the liquid 120 existing therein is less than a predetermined number. On the other hand, as a result of the comparison, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal input from the light receiver 62 exceeds the second allowable value and is equal to or lower than the second allowable value, It is determined that the number of bubbles generated in the liquid 120 existing in is equal to or greater than a predetermined number. Here, the predetermined number is a value that does not hinder the flow of the liquid 120. When the number of bubbles contained in the liquid 120 in the nozzle head 106 is further increased from the predetermined number and a large number of bubbles corresponding to the second threshold shown in FIG. 6 are generated, the flow of the liquid 120 is inhibited.

When the control unit 119 determines that the light transmittance based on the received light intensity signal level detected by the optical sensor unit 60 has exceeded the second allowable value, the control unit 119 causes the carriage 105 of the nozzle moving unit to move the nozzle head. 106 is moved to the sealing cap 9 at the standby position, and a process of removing bubbles remaining in the nozzle head 106 is executed.
In particular, the control unit 119 corresponds to the timing at which the liquid 120 exceeds the second allowable value (30%) based on the light transmittance detected by the light sensor unit 60 and the liquid 120 cannot be ejected from the nozzle head 106. The nozzle head 106 is moved to the standby position until the second threshold value (for example, 20%) of the light transmittance to be reached, and processing for removing bubbles remaining in the nozzle head 106 is executed. Specifically, the control unit 119 predicts the time until timing T when the light transmittance detected by the optical sensor unit 60 becomes the second threshold (20%), and the control unit 119 operates the carriage 105 by that timing. Then, the nozzle head 106 is moved to the standby position, and a process of removing bubbles remaining in the nozzle head 106 is executed.
Note that the nozzle head 106 is moved to the standby position by the timing T when the light transmittance detected by the optical sensor unit 60 reaches the second threshold (20%), and the bubbles remaining in the nozzle head 106 are removed. The processing operation will be described later.

The functions of the control unit 119 as the first comparator and the second comparator may be realized by a logic circuit or may be realized by executing a program.
Further, since the light transmittance detected by the optical sensor unit 60 varies depending on the hue and density of the liquid 120 and the capacity of the space 163 in the nozzle head 106, the above-described initial value, allowable value, and threshold value are as follows. It is an example. Since the initial value, the allowable value, and the threshold value are different for each liquid 120 and each nozzle head 106, they are different for each coating apparatus 100.

  In FIG. 1, the number of nozzle heads 106 mounted on the carriage 105 is one, but a plurality of nozzle heads 106 may be mounted on the carriage 105. In this case, these nozzle heads 106 are mounted on the carriage 105 in a state of being arranged along the sub-scanning direction. When a plurality of nozzle heads 106 are mounted on the carriage 105, a supply pipe 107, a liquid tank 108, and a mass flow controller 109 are provided for each nozzle head 106.

  Further, although the carriage 105 is moved in the main scanning direction, it may be moved in the main scanning direction and the sub scanning direction. Further, the nozzle head 106 may rotate around its center line. Although the work table 101 is moved in the sub-scanning direction by the moving device 102, it may be moved in the main scanning direction and the sub-scanning direction by the moving device 102. Further, the work table 101 may be rotated around its center by the moving device 102.

[2] Operation of Coating Apparatus and Coating Method Hereinafter, the operation of the coating apparatus 100 and the coating method using the coating apparatus 100 will be described.

  First, the liquid 120 is filled in the liquid tank 108. When the liquid tank 108 is replaceable, the liquid tank 108 filled with the liquid 120 is assembled to the supply pipe 107, and the supply device 116 is assembled to the liquid tank 108. At this time, the supply pipe 107 is empty, and the liquid 120 is not filled in the supply pipe 107.

Next, the control unit 119 operates the carriage 105 to move the nozzle head 106 to the standby position, and closes the lower end of the nozzle head 106 with the sealing cap 150. Then, the control unit 119 operates the vacuum pump 140 to operate the supply unit 116 while reducing the pressure in the supply pipe 107 and the nozzle head 106, thereby causing the liquid 120 in the liquid tank 108 to flow into the supply pipe 107. To the nozzle head 106.
Further, the control unit 119 sets the set flow rate of the mass flow controller 109 and adjusts the amount of the liquid 120 ejected from the nozzle head 106.

Next, the substrate 121 is placed on the work table 101.
As shown in FIG. 7, the substrate 121 is a region where a portion that is cut out from the substrate 121 and becomes the EL panel (1) is arranged, and a panel region R1 that is a coating target region to which the liquid 120 is to be applied. A plurality of margin regions R2 that are non-target regions that do not need to be coated with the liquid 120 between the panel regions R1 are alternately arranged.

  Next, the control unit 119 operates the supply device 116 and the carriage 105. Note that the supply device 116 that sends out the liquid 120 in the liquid tank 108 into the supply pipe 107 continues to operate.

The control unit 119 operates the carriage 105 and the nozzle head 106 moves in the main scanning direction together with the carriage 105. At this time, since the supply device 116 is operating, the liquid 120 in the liquid tank 108 is sent out to the nozzle head 106, and the flow rate of the liquid 120 flowing through the supply pipe 107 is controlled to a constant set flow rate by the mass flow controller 109. The Therefore, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106 during the movement of the carriage 105. Therefore, the discharged liquid 120 is applied linearly on the substrate 121, and a linear organic layer pattern along the main scanning direction is formed on the substrate 121. When the carriage 105 moves to the opposite end of the movement range, the control unit 119 stops the carriage 105.
Next, the control unit 119 controls the moving device 102, and the work table 101 and the substrate 121 are moved by a predetermined distance in the sub-scanning direction by the moving device 102. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the sub-scanning direction is formed on the substrate 121. Thereafter, the moving device 102 stops.
Next, the control unit 119 operates the carriage 105, and the nozzle head 106 moves with the carriage 105 in the reverse direction of the main scanning direction. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the main scanning direction is formed on the substrate 121. When the carriage 105 moves to the opposite end of the movement range, the control unit 119 stops the carriage 105.
Next, the control unit 119 controls the moving device 102, and the work table 101 and the substrate 121 are moved by a predetermined distance in the sub-scanning direction by the moving device 102. Also at this time, the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Therefore, a linear organic layer pattern along the main scanning direction is formed on the substrate 121.

Thereafter, the control unit 119 repeats the control of the carriage 105 and the moving device 102 and the control of the feeder 116 and the mass flow controller 109. Accordingly, the carriage 105 is repeatedly moved from end to end in the movement range while the liquid 120 is continuously ejected from the nozzle holes 168 of the nozzle head 106, and the moving device 102 is moved when the carriage 105 moves to the end. As a result, the work table 101 and the substrate 121 are moved in the sub-scanning direction by a predetermined distance. As a result, a twisted organic layer pattern is formed on the substrate 121 by the liquid 120 ejected from the nozzle head 106.
Here, the control unit 119 applies the liquid 120 and grasps the current position of the moving nozzle head 106. This is because the current position of the nozzle head 106 relative to the substrate 121 is specified by the control unit 119 performing predetermined arithmetic processing based on the size of the substrate 121, the movement range and movement speed of the carriage 105 and the moving device 102. Is possible.
Further, the control unit 119 can predict the location where the nozzle head 106 is located after a predetermined time from the current position by performing the same calculation process.

By the way, when the control unit 119 repeats the control of the carriage 105, the moving device 102, the supply device 116, the mass flow controller 109 and the like to apply the liquid 120 onto the substrate 121, the light reception from the optical sensor unit 60. An intensity signal is input to the control unit 119.
The control unit 119 compares the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 with the first tolerance value, the first threshold value, the second tolerance value, and the second threshold value.
When the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 does not exceed the first allowable value and the second allowable value as a result of the comparison, the application of the liquid 120 described above is performed. Continue to control.
On the other hand, if the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 exceeds the first allowable value or the second allowable value as a result of the comparison, the control unit 119 performs the following processing.

When the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 exceeds the first allowable value, the control unit 119 sets the level of the received light intensity signal that is the light transmittance detected by the optical sensor unit 60. The timing at which the light transmittance based on becomes the first threshold is predicted. As shown in FIG. 6, the timing at which the light transmittance based on the level of the received light intensity signal becomes the first threshold value is such that the light transmittance based on the level of the received light intensity signal is from the initial value (for example, 40%) to the first allowable value ( For example, the time (T) until the first threshold value (for example, 80%) is reached can be obtained by a calculation process based on the time until it reaches 60%).
Similarly, when the control unit 119 determines that the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 has exceeded the second allowable value, the received light intensity signal that is the light transmittance detected by the optical sensor unit 60. The timing at which the level becomes the second threshold is predicted. The timing at which the light transmittance based on the level of the received light intensity signal becomes the second threshold, as shown in FIG. 6, the light transmittance based on the level of the received light intensity signal is from the initial value (for example, 40%) to the second allowable value ( For example, the time (T) until the second threshold value (for example, 20%) is reached can be obtained by a calculation process based on the time until it reaches 30%).

Then, the control unit 119 arranges the nozzle head 106 at the timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value, or at the timing when the light transmittance based on the level of the received light intensity signal becomes the second threshold value. Yes, the position of the nozzle head 106 relative to the substrate 121 is predicted and specified.
Further, in the control unit 119, the position of the nozzle head 106 with respect to the substrate 121 at the timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value is the application target region where the liquid 120 is to be applied. It is determined whether the position corresponds to the panel area R1 of the substrate 121 or the position corresponding to the margin area R2 of the substrate 121, which is a non-target area between which the liquid 120 is not applied, between the panel areas R1. To do.

When the control unit 119 determines that the position of the nozzle head 106 at the timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value is a position corresponding to the margin region R2 of the substrate 121. At the timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value, the nozzle head 106 located at the position corresponding to the margin region R2 is moved to the contact cap 150 at the standby position, A defoaming process for removing bubbles remaining in the nozzle head 106 is executed.
That is, when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value, and when the liquid 120 cannot be ejected from the nozzle head 106, the nozzle head 106 is in the margin area of the substrate 121. If it is at a position corresponding to R2, the liquid 120 may be interrupted in the margin region R2. Then, by removing the bubbles in the nozzle head 106 located at the position corresponding to the margin area R2, the liquid 120 can be continuously discharged again from the nozzle head 106, so that the next panel area R1 is discharged. The application of the liquid 120 can be suitably restarted.

On the other hand, the control unit 119 determines that the position of the nozzle head 106 at a timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value is a position corresponding to the panel region R1 of the substrate 121. In this case, the nozzle head 106 located at the position corresponding to the margin region R2 before the panel region R1 where the level of the light intensity signal becomes the first threshold value or the second threshold value is moved in advance to the contact cap 150 at the standby position, A defoaming process for removing bubbles remaining in the nozzle head 106 is executed.
That is, the nozzle head 106 moves to the panel area of the substrate 121 at a timing when the light transmittance based on the level of the received light intensity signal becomes the first threshold value or the second threshold value, and the liquid 120 cannot be ejected from the nozzle head 106. If the liquid 120 is interrupted in the panel region R1 at the position corresponding to R1, the productivity of the EL panel is lowered. Therefore, before the liquid 120 is interrupted in the panel area R1, the liquid 120 is ejected from the nozzle head 106 by removing bubbles in the nozzle head 106 at a position corresponding to the margin area R2 before the panel area R1. Before it becomes impossible, the liquid 120 can be continuously discharged from the nozzle head 106, and the liquid 120 can be suitably applied also to the next panel region R1.

  When the nozzle head 106 is moved to the close-contact cap 150 at the standby position to remove bubbles in the nozzle head 106, the control unit 119 transmits light based on the received light intensity signal level of the optical sensor unit 60. As the rate reaches the initial value (for example, 40%), it is determined that the bubbles in the nozzle head 106 have been removed and the defoaming process has been completed.

  When the defoaming process in the nozzle head 106 is completed, the control unit 119 of the coating apparatus 100 operates the carriage 105 and the like to a position corresponding to the margin region R2 where the coating is suspended for the defoaming process. Move. The controller 119 restarts the operation of applying the liquid 120 ejected from the nozzle head 106 to the substrate 121 by repeating the control of the carriage 105 and the moving device 102 and the control of the feeder 116 and the mass flow controller 109.

As described above, the coating apparatus 100 detects the light transmittance of the liquid 120 in the nozzle head 106 by the optical sensor unit 60 provided in the nozzle head 106, and determines the size of bubbles remaining in the nozzle head 106. The amount can be determined.
In the coating apparatus 100, after the light transmittance based on the level of the received light intensity signal of the optical sensor unit 60 exceeds the first allowable value or the second allowable value, the liquid 120 cannot be ejected from the nozzle head 106. Since the air bubbles staying in the nozzle head 106 can be removed by moving the nozzle head 106 to the standby position, there is a problem that the application of the liquid 120 is interrupted due to the excessive accumulation of air bubbles in the nozzle head 106. Can be reduced.

In particular, the control unit 119 of the coating apparatus 100 has the first threshold value or the second threshold value corresponding to the timing at which the liquid 120 cannot be ejected from the nozzle head 106 based on the level of the received light intensity signal of the optical sensor unit 60. When it is determined that the nozzle head 106 is in a position corresponding to the panel region R1 of the substrate 121 at the predicted timing, the nozzle head 106 is moved in the margin region R2 before the panel region R1. Bubbles staying in the nozzle head 106 can be removed by moving to the standby position.
If the nozzle head 106 is at a position corresponding to the margin region R2 of the substrate 121 at a timing corresponding to the first threshold or the second threshold corresponding to the timing at which the liquid 120 cannot be ejected from the nozzle head 106, the controller 119 When the determination is made, the nozzle head 106 that has reached the position corresponding to the margin region R2 can be moved to the standby position to remove the bubbles remaining in the nozzle head 106.
In this way, the control unit 119 predicts the timing at which the liquid 120 cannot be ejected from the nozzle head 106, and before the liquid 120 can be ejected from the nozzle head 106, the control unit 119 moves the nozzle head 106 at the position corresponding to the margin region R <b> 2. Since the defoaming process in the nozzle head 106 is performed by moving to the standby position, the liquid 120 is interrupted in the panel region R1 of the substrate 121 without interrupting the application of the liquid 120 in the panel region R1 of the substrate 121. There is no.
Therefore, the coating apparatus 100 can satisfactorily apply the liquid 120 to the substrate 121.

The nozzle head 106 of the coating apparatus 100 is not limited to the above embodiment.
For example, as shown in FIG. 8, a filter 164 may be disposed in the middle of the space 163 of the nozzle head main body 161, and the space 163 may be partitioned into the inlet 162 side and the opening 166 side.
A pair of transparent windows 60c and 60d having light transmittance are provided on the side surfaces of the nozzle head main body 161 corresponding to the space 163 portion above the filter 164 at positions facing each other across the space 163. In addition, a projector 611 that emits predetermined light toward the space 163 is provided outside the one transparent window 60c, and a light receiver 621 that detects the light that has passed through the space 163 is provided outside the other transparent window 60d. ing. The light sensor 601 and the light receiver 621 constitute the light sensor unit 60.
In addition, a pair of transparent windows 60e and 60f having light transmittance are provided on the side surfaces of the nozzle head main body 161 corresponding to the space 163 portion below the filter 164 at positions facing each other across the space 163. Further, a light projector 612 that emits predetermined light toward the space 163 is provided outside the one transparent window 60e, and a light receiver 622 that detects light that has passed through the space 163 is provided outside the other transparent window 60f. ing. This light projector 612 and light receiver 622 constitute an optical sensor unit 60.
As described above, one nozzle head 106 may be provided with two or more optical sensor units 60.
In addition, when the properties of the bubbles staying in the space 163 above the filter 164 and the space 163 below the filter 164 are different, different allowable values and threshold values may be set for each space.

[3] Configuration of Organic Electroluminescence Display Panel (EL Panel) Manufactured Using Coating Device The EL panel 1 manufactured using the coating device 100 shown in FIG. 1 will be described with reference to FIGS. To do.
The EL panel 1 is obtained by cutting out a plurality of EL panels 1 (see FIG. 7) formed on a large substrate 121. The substrate 10 in the EL panel 1 is a small substrate corresponding to one EL panel 1 formed by dividing a large substrate 121.

  FIG. 9 is a plan view showing an arrangement configuration of a plurality of pixels P in the EL panel 1 which is a light emitting panel. FIG. 10 is a plan view showing a schematic configuration of the EL panel 1. FIG. 11 is a circuit diagram showing a circuit corresponding to one pixel of the EL panel 1 operating in the active matrix driving method. 12 is a plan view corresponding to one pixel P of the EL panel 1, and FIG. 13 is a cross-sectional view taken along the line XIII-XIII in FIG.

As shown in FIGS. 9 and 10, on the EL panel 1, a plurality of pixels P that respectively emit R (red), G (green), and B (blue) are arranged in a matrix with a predetermined pattern. .
In the EL panel 1, a plurality of scanning lines 2 are arranged so as to be substantially parallel to each other along the row direction, and the plurality of signal lines 3 are arranged along the column direction so as to be substantially orthogonal to the scanning lines 2 in plan view. They are arranged so as to be substantially parallel to each other. A voltage supply line 4 is provided along the scanning line 2 between the adjacent scanning lines 2. A range surrounded by the two signal lines 3 adjacent to the scanning lines 2 and the voltage supply lines 4 corresponds to the pixel P. Here, a plurality of pixels P that emit R (red), a plurality of pixels P that emit G (green), and a plurality of pixels P that emit B (blue), respectively, along the arrangement direction of the signal lines 3. The pixels P are arranged side by side, and are arranged in the order of the pixels P that emit R (red), the pixels P that emit G (green), and the pixels P that emit B (blue) along the arrangement direction of the scanning lines 2. .

  Further, the EL panel 1 is provided with a bank 13 that is a partition wall extending in a direction along the signal line 3. Predetermined carrier transport layers (a hole injection layer 8b and a light emitting layer 8c described later) are provided in a range sandwiched between the banks 13 and become a light emitting region of the pixel P. That is, the bank 13 partitions the pixel P for each color of R (red), G (green), and B (blue). The carrier transport layer is a layer that transports holes or electrons when a voltage is applied.

  As shown in FIGS. 10 and 11, the EL panel 1 is provided with a scanning line 2, a signal line 3 intersecting with the scanning line 2, and a voltage supply line 4 along the scanning line 2. A switch transistor 5 that is a thin film transistor, a drive transistor 6 that is a thin film transistor, a capacitor 7, and an EL element 8 are provided for each pixel P of the panel 1.

  In each pixel P, the gate of the switch transistor 5 is connected to the scanning line 2, one of the drain and source of the switch transistor 5 is connected to the signal line 3, and the other of the drain and source of the switch transistor 5 is It is connected to one electrode of the capacitor 7 and the gate of the driving transistor 6. One of the source and drain of the driving transistor 6 is connected to the voltage supply line 4, and the other of the source and drain of the driving transistor 6 is connected to the other electrode of the capacitor 7 and the anode of the EL element 8. Note that the cathodes of the EL elements 8 of all the pixels P are kept at a constant voltage Vcom (for example, grounded).

  In addition, each scanning line 2 is connected to a scanning driver around the EL panel 1. Each voltage supply line 4 is connected to a constant voltage source or a driver that outputs a voltage signal as appropriate. Each signal line 3 is connected to a data driver. The EL panel 1 is driven by these drivers by an active matrix driving method. The voltage supply line 4 is supplied with predetermined power by a constant voltage source or a driver.

Next, the circuit structure of the EL panel 1 and the pixel P will be described with reference to FIGS.
As shown in FIG. 12, the switch transistor 5 and the drive transistor 6 are arranged along the signal line 3. The capacitor 7 is disposed in the vicinity of the switch transistor 5. The EL element 8 is disposed in the vicinity of the driving transistor 6. Further, the switch transistor 5, the drive transistor 6, the capacitor 7, and the EL element 8 are disposed between the scanning line 2 and the voltage supply line 4.

As shown in FIG. 13, the drive transistor 6 includes a gate electrode 6a, a semiconductor film 6b, a channel protective film 6d, impurity semiconductor films 6f and 6g, a drain electrode 6h, a source electrode 6i, and the like.
The switch transistor 5 is a thin film transistor similar to the drive transistor 6 described in detail below, and includes a gate electrode 5a, a semiconductor film, a channel protective film, an impurity semiconductor film, a drain electrode 5h, a source electrode 5i, and the like. Details are omitted here.
As shown in FIGS. 12 and 13, an interlayer insulating film 11 serving as a gate insulating film is formed on one surface of the substrate 10, and an interlayer insulating film 12 is formed on the interlayer insulating film 11. . The signal line 3 is formed between the interlayer insulating film 11 and the substrate 10, and the scanning line 2 and the voltage supply line 4 are formed between the interlayer insulating film 11 and the interlayer insulating film 12.

The gate electrode 6 a is formed between the substrate 10 and the interlayer insulating film 11. The gate electrode 6a is made of, for example, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film. An insulating interlayer insulating film 11 is formed on the gate electrode 6a. Gate electrode 6 a is covered with interlayer insulating film 11.
The interlayer insulating film 11 is made of, for example, silicon nitride or silicon oxide. An intrinsic semiconductor film 6b is formed on the interlayer insulating film 11 at a position corresponding to the gate electrode 6a. The semiconductor film 6b is opposed to the gate electrode 6a with the interlayer insulating film 11 interposed therebetween.
The semiconductor film 6b is made of, for example, amorphous silicon or polycrystalline silicon. A channel is formed in the semiconductor film 6b. An insulating channel protective film 6d is formed on the central portion of the semiconductor film 6b. The channel protective film 6d is made of, for example, silicon nitride or silicon oxide.
Further, an impurity semiconductor film 6f is formed on one end portion of the semiconductor film 6b so as to partially overlap the channel protective film 6d. Over the other end of the semiconductor film 6b, an impurity semiconductor film 6g is formed so as to partially overlap the channel protective film 6d. The impurity semiconductor films 6f and 6g are formed on both ends of the semiconductor film 6b so as to be separated from each other. Here, the impurity semiconductor films 6f and 6g are n-type semiconductors, but the present invention is not limited thereto, and may be p-type semiconductors.
A drain electrode 6h is formed on the impurity semiconductor film 6f. A source electrode 6i is formed on the impurity semiconductor film 6g. The drain electrode 6h and the source electrode 6i are made of, for example, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film, or an AlTiNd alloy film.
An insulating interlayer insulating film 12 serving as a protective film is formed on the channel protective film 6d, the drain electrode 6h, and the source electrode 6i. The channel protective film 6d, the drain electrode 6h, and the source electrode 6i are covered with the interlayer insulating film 12. The drive transistor 6 is covered with an interlayer insulating film 12. The interlayer insulating film 12 is made of, for example, silicon nitride or silicon oxide having a thickness of 100 nm to 200 nm.

  The capacitor 7 is connected between the gate electrode 6 a and the source electrode 6 i of the driving transistor 6. As shown in FIG. 13, one electrode 7 a of the capacitor 7 is formed between the substrate 10 and the interlayer insulating film 11. The other electrode 7 b of the capacitor 7 is formed between the interlayer insulating film 11 and the interlayer insulating film 12. The electrodes 7a and 7b are opposed to each other with the interlayer insulating film 11 as a dielectric interposed therebetween. Thereby, the capacitor 7 is configured.

Note that the signal line 3, the electrode 7a of the capacitor 7, the gate electrode 5a of the switch transistor 5, and the gate electrode 6a of the drive transistor 6 are formed by forming a conductive film formed over the substrate 10 by a photolithography method, an etching method, or the like. It is formed at a time by processing.
The scanning line 2, the voltage supply line 4, the electrode 7 b of the capacitor 7, the drain electrode 5 h and source electrode 5 i of the switch transistor 5, and the drain electrode 6 h and source electrode 6 i of the driving transistor 6 are formed on the interlayer insulating film 11. The formed conductive film is formed by shape processing by a photolithography method, an etching method, or the like.

In the interlayer insulating film 11, a contact hole 11a is formed in a region where the gate electrode 5a and the scanning line 2 overlap. A contact hole 11b is formed in a region where the drain electrode 5h and the signal line 3 overlap. A contact hole 11c is formed in a region where the gate electrode 6a and the source electrode 5i overlap. Contact plugs 20a to 20c are buried in the contact holes 11a to 11c, respectively.
The gate electrode 5a of the switch transistor 5 and the scanning line 2 are electrically connected by the contact plug 20a. The contact plug 20b electrically connects the drain electrode 5h of the switch transistor 5 and the signal line 3. The contact plug 20c electrically connects the source electrode 5i of the switch transistor 5 and the electrode 7a of the capacitor 7, and electrically connects the source electrode 5i of the switch transistor 5 and the gate electrode 6a of the drive transistor 6.
The scanning line 2 may be in direct contact with the gate electrode 5a, the drain electrode 5h may be in contact with the signal line 3, and the source electrode 5i may be in contact with the gate electrode 6a without using the contact plugs 20a to 20c.
The gate electrode 6 a of the drive transistor 6 is integrally connected to the electrode 7 a of the capacitor 7. A drain electrode 6 h of the drive transistor 6 is integrally connected to the voltage supply line 4. A source electrode 6 i of the driving transistor 6 is integrally connected to an electrode 7 b of the capacitor 7.

The pixel electrode 8 a is provided on the substrate 10 via the interlayer insulating film 11, and the pixel electrode 8 a is formed independently for each pixel P. The pixel electrode 8a is a transparent electrode, for example, tin-doped indium oxide (ITO), zinc-doped indium oxide, indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), zinc oxide (ZnO), or cadmium − It consists of tin oxide (CTO). The pixel electrode 8a partially overlaps the source electrode 6i of the drive transistor 6, and the pixel electrode 8a and the source electrode 6i are connected.
As shown in FIGS. 12 and 13, the interlayer insulating film 12 includes the scanning line 2, the signal line 3, the voltage supply line 4, the switch transistor 5, the driving transistor 6, the peripheral edge of the pixel electrode 8 a, and the electrode of the capacitor 7. 7b and the interlayer insulating film 11 are formed.
An opening 12a is formed in the interlayer insulating film 12 so that the center of each pixel electrode 8a is exposed. The interlayer insulating film 12 is formed in a lattice shape in plan view.

As shown in FIGS. 12 and 13, the bank 13 extends in the direction along the signal line 3 and is provided in parallel to each other. Therefore, these banks 13 are striped. The bank 13 is formed at a position covering the switch transistor 5 and the drive transistor 6 with the interlayer insulating film 12 interposed therebetween.
The side wall 13a of the bank 13 is located inside the opening 12a of the interlayer insulating film 12, and the center side of the pixel electrode 8a is exposed between the opposing side walls 13a.
In the bank 13, when a hole injection layer 8b or a light emitting layer 8c described later is formed by a wet method, a liquid material in which a material for forming the hole injection layer 8b or the light emitting layer 8c is dissolved or dispersed in a solvent is adjacent. It functions as a partition wall that prevents the pixel P from bleeding.

  As shown in FIGS. 12 and 13, the EL element 8 includes a pixel electrode 8a as a first electrode serving as an anode, a hole injection layer 8b that is a compound film formed on the pixel electrode 8a, and a hole. A light emitting layer 8c, which is a compound film formed on the injection layer 8b, and a counter electrode 8d as a second electrode formed on the light emitting layer 8c are provided. The counter electrode 8d is a single electrode common to all the pixels P, and is continuously formed in all the pixels P.

The hole injection layer 8b is a carrier transport layer made of, for example, PEDOT (poly (ethylenedioxy) thiophene) that is a conductive polymer and PSS (polystyrene sulfonate) that is a dopant. The hole injection layer 8b is a layer that injects holes from the pixel electrode 8a toward the light emitting layer 8c.
The light emitting layer 8c includes a material that emits one of R (red), G (green), and B (blue) for each pixel P. The light emitting layer 8c is a carrier transport layer made of, for example, a polyfluorene light emitting material or a polyphenylene vinylene light emitting material. The light emitting layer 8c is a layer that emits light in association with recombination of electrons supplied from the counter electrode 8d and holes injected from the hole injection layer 8b. For this reason, the pixel P that emits R (red), the pixel P that emits G (green), and the pixel P that emits B (blue) have different light emitting materials for the light emitting layer 8c. The R (red), G (green), and B (blue) pattern of the pixel P is a stripe pattern in which the same color pixels are arranged in the vertical direction.

The counter electrode 8d is formed of a material having a work function lower than that of the pixel electrode 8a. The counter electrode 8d is made of, for example, a simple substance or an alloy containing at least one of indium, magnesium, calcium, lithium, barium, and a rare earth metal.
The counter electrode 8d is an electrode common to all the pixels P, and covers the bank 13 together with the compound film such as the light emitting layer 8c.

Further, the hole injection layer 8 b and the light emitting layer 8 c are provided in a band shape in the direction along the bank 13 between the adjacent banks 13, and are provided continuously in the direction along the bank 13. Therefore, the hole injection layer 8 b and the light emitting layer 8 c are not divided for each pixel P in the direction along the bank 13. That is, the hole injection layer 8 b and the light emitting layer 8 c are provided in common to the plurality of pixel electrodes 8 a arranged between the adjacent banks 13. On the other hand, the hole injection layer 8 b and the light emitting layer 8 c are partitioned by the bank 13 in the direction orthogonal to the bank 13.
A hole injection layer 8b and a light emitting layer 8c as a carrier transport layer are stacked on the pixel electrode 8a between the sidewalls 13a of the bank 13 in the opening 12a of the interlayer insulating film 12 (see FIG. 13). . That is, when a voltage is applied between the pixel electrode 8a and the counter electrode 8d, the hole injection layer 8b and the light emitting layer 8c function as a carrier transport layer in a portion overlapping the pixel electrode 8a, and light emission occurs in that portion of the light emitting layer 8c. To do.
Specifically, the sidewall 13 a of the bank 13 provided on the interlayer insulating film 12 is formed inside the opening 12 a of the interlayer insulating film 12.
Then, a liquid material containing a material to be the hole injection layer 8b is applied on the pixel electrode 8a surrounded by the opening 12a and sandwiched between the side walls 13a, and the substrate 10 is heated to dry the liquid material. The compound film thus formed becomes the hole injection layer 8b which is the first carrier transport layer.
Further, a liquid material containing a material to be the light emitting layer 8c is applied on the hole injection layer 8b surrounded by the opening 12a and sandwiched by the side walls 13a, and the substrate 10 is heated to dry the liquid material. The compound film thus formed becomes the light emitting layer 8c which is the second carrier transport layer.
A counter electrode 8d is provided so as to cover the light emitting layer 8c and the bank 13 (see FIG. 13).

In this EL panel 1, the pixel electrode 8a, the substrate 10 and the interlayer insulating film 11 are transparent, and the light emitted from the light emitting layer 8c is transmitted through the pixel electrode 8a, the interlayer insulating film 11 and the substrate 10 and emitted. . Therefore, the back surface of the substrate 10 becomes a display surface.
The display surface may be the opposite side instead of the substrate 10 side. In this case, the counter electrode 8d is a transparent electrode, the pixel electrode 8a is a reflective electrode, and light emitted from the light emitting layer 8c is transmitted through the counter electrode 8d and emitted.

The EL panel 1 is driven as follows to emit light.
In a state where a predetermined level of voltage is applied to all the voltage supply lines 4, the scanning driver sequentially applies voltages to the scanning lines 2, thereby sequentially selecting the scanning lines 2.
When each scanning line 2 is selected, if a voltage of a level corresponding to the gradation is applied to all the signal lines 3 by the data driver, the switch transistor 5 corresponding to the selected scanning line 2 is turned on. Therefore, a voltage of a level corresponding to the gradation is applied to the gate electrode 6a of the drive transistor 6.
The potential difference between the gate electrode 6a and the source electrode 6i of the drive transistor 6 is determined according to the voltage applied to the gate electrode 6a of the drive transistor 6, and the magnitude of the drain-source current in the drive transistor 6 is determined. The EL element 8 emits light with brightness according to the drain-source current.
Thereafter, when the selection of the scanning line 2 is released, the switch transistor 5 is turned off, so that the charge according to the voltage applied to the gate electrode 6a of the driving transistor 6 is stored in the capacitor 7 and the driving transistor 6 The potential difference between the gate electrode 6a and the source electrode 6i is maintained.
For this reason, the drive transistor 6 keeps flowing the drain-source current having the same current value as that at the time of selection, and maintains the luminance of the EL element 8.

[4] Manufacturing Method of Organic Electroluminescence Display Panel (EL Panel) Using Coating Device Next, a manufacturing method of the EL panel 1 will be described.

[4-1] Process before using the coating apparatus (mainly transistor manufacturing process)
First, a gate metal layer is deposited on the substrate 121 to be the substrate 10 by sputtering. Then, the gate metal layer is patterned by photolithography and etching. Thus, the signal line 3, the electrode 7a of the capacitor 7, the gate electrode 5a of the switch transistor 5 and the gate electrode 6a of the drive transistor 6 are formed from the gate metal layer.
Next, an interlayer insulating film 11 to be a gate insulating film such as silicon nitride is deposited by plasma CVD. A contact hole (not shown) opened on the external connection terminal (for example, the end of the scanning line 2) of each scanning line 2 for connecting to a scanning driver located on one side of the EL panel 1 is formed in the interlayer insulating film 11. Form.
Next, a semiconductor layer such as amorphous silicon to be the semiconductor film 6b (5b) and an insulating layer such as silicon nitride to be the channel protective film 6d (5d) are successively deposited. Thereafter, the insulating layer is patterned by photolithography and etching. Thereby, a channel protective film 6d (5d) is formed from the insulating film.
Thereafter, an impurity layer to be the impurity semiconductor films 6f and 6g (5f and 5g) is deposited, and then the impurity layer and the semiconductor layer are successively patterned by photolithography and etching. Thereby, impurity semiconductor films 6f and 6g (5f and 5g) are formed from the impurity layer, and a semiconductor film 6b (5b) is formed from the semiconductor layer.
Then, contact holes 11a to 11c are formed by photolithography and etching. Next, contact plugs 20a to 20c are formed in the contact holes 11a to 11c. This step may be omitted.
A source / drain metal layer to be the drain electrode 5h and source electrode 5i of the switch transistor 5 and the drain electrode 6h and source electrode 6i of the driving transistor 6 is deposited, and the source / drain metal layer is patterned. Thus, the scanning line 2, the voltage supply line 4, the electrode 7b of the capacitor 7, the drain electrode 5h of the switch transistor 5, the source electrode 5i, the drain electrode 6h of the driving transistor 6, and the source electrode 6i are formed from the source / drain metal layer. To do. Thus, the switch transistor 5 and the drive transistor 6 are formed. Then, after depositing an ITO film, the ITO film is patterned to form a pixel electrode 8a from the ITO film.

  Then, an insulating film is formed by vapor deposition so as to cover the switch transistor 5, the drive transistor 6, and the like. Thereafter, the insulating film is patterned by photolithography and etching. Thus, a plurality of openings 12a are formed in the insulating film, and the interlayer insulating film 12 is formed. The opening 12a is formed at the center of each pixel electrode 8a, and the center of the pixel electrode 8a is exposed in each opening 12a. In addition to these openings 12a, the external connection terminals of the scanning lines 2 (not shown) and the external connection terminals of the signal lines 3 for connection to the data driver located on one side of the EL panel 1 (for example, the end portions of the signal lines 3) And a plurality of contact holes opened on the external connection terminals of the voltage supply line 4 (for example, end portions of the voltage supply line 4).

  Next, after depositing a photosensitive resin such as polyimide, the photosensitive resin is exposed to form striped banks 13 parallel to each other. At this time, the bank 13 is formed so that the side wall 13a of the bank 13 is positioned on the pixel electrode 8a. The bank 13 exposes a contact hole (not shown) that opens the external connection terminal.

  Through the above steps, each pixel electrode 8a is exposed in each opening 12a of the interlayer insulating film 12, as shown in FIG. A plurality of pixel electrodes 8 a are exposed in the recesses between the striped banks 13, and the pixel electrodes 8 a are arranged along the banks 13.

[4-2] Application Process Using Application Device In order to apply a liquid serving as a carrier transport layer onto the pixel electrodes 8a between the banks 13, four application devices 100 are set.
The liquid tank 108 of the first coating apparatus 100 is filled with a liquid 120 of a material that becomes the hole injection layer 8b. The liquid tank 108 of the second coating apparatus 100 is filled with a liquid 120 of a material that becomes the red light emitting layer 8c. The liquid tank 108 of the third coating apparatus 100 is filled with a liquid 120 of a material that becomes the green light emitting layer 8c. The liquid tank 108 of the fourth coating apparatus 100 is filled with a liquid 120 of a material that becomes the blue light emitting layer 8c.

Next, in the previous step, the substrate 121 formed up to the bank 13 is placed on the work table 101 of the first coating apparatus 100. At this time, the substrate 121 is placed on the work table 101 so that the extending direction of the bank 13 is along the main scanning direction.
The set flow rate of the mass flow controller 109 is set under the control of the control unit 119.

Next, the supply unit 116 and the carriage 105 are operated by the control unit 119, the carriage 105 moves in the main scanning direction from one end of the movement range, and the liquid 120 is continuously discharged from the nozzle holes 168 of the nozzle head 106. Is done. Then, the discharged liquid 120 is applied between the adjacent banks 13. As a result, a band-shaped hole injection layer 8b is formed between the adjacent banks 13, and the pixel electrodes 8a arranged between the adjacent banks 13 are covered with the hole injection layer 8b.
When the carriage 105 moves to the opposite end of the movement range, the carriage 105 is stopped by the control unit 119. Then, the control unit 119 controls the moving device 102, the work table 101 and the substrate 121 are moved by one pixel in the sub-scanning direction by the moving device 102, and then the moving device 102 is stopped by the control unit 119.

Next, the control unit 119 operates the carriage 105. As a result, the carriage 105 moves in the reverse direction, and the liquid 120 is continuously ejected from the nozzle holes 168 of the nozzle head 106 to form the band-shaped hole injection layer 8b.
When the carriage 105 moves to one end of the movement range, the carriage 105 is stopped by the control unit 119. Then, the control unit 119 controls the moving device 102, the work table 101 and the substrate 121 are moved by one pixel in the sub-scanning direction by the moving device 102, and then the moving device 102 is stopped by the control unit 119.

Thereafter, the control unit 119 repeats the control of the carriage 105 and the moving device 102 and the control of the feeder 116 and the mass flow controller 109. Accordingly, the carriage 105 is repeatedly moved from end to end in the movement range while the liquid 120 is continuously ejected from the nozzle holes 168 of the nozzle head 106, and the moving device 102 is moved when the carriage 105 moves to the end. Thus, the work table 101 and the substrate 121 are moved in the sub-scanning direction by a predetermined distance. As a result, the liquid 120 discharged from the nozzle head 106 is applied on the substrate 121 in a twisted pattern (see FIG. 7).
Then, all the pixel electrodes 8a on the substrate 121 are covered with the hole injection layer 8b.

  Next, after the hole injection layer 8 b is dried, the substrate 121 is placed on the work table 101 of the second coating apparatus 100. Then, the second coating apparatus 100 performs the same coating, whereby a strip-shaped red light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 121 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is equivalent to three pixels. Then, a red light emitting layer 8c is formed every three columns in the main scanning direction.

  Next, the substrate 121 is placed on the work table 101 of the third coating apparatus 100. Then, the third coating apparatus 100 performs the same coating, whereby a strip-shaped green light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 121 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is equivalent to three pixels. And the green light emitting layer 8c is formed for every 3 rows of the main scanning direction.

  Next, the substrate 121 is placed on the work table 101 of the fourth coating apparatus 100. Then, when the fourth coating apparatus 100 performs the same coating, a band-like blue light emitting layer 8c is formed on the hole injection layer 8b. Here, the work table 101 and the substrate 121 are intermittently moved in the sub-scanning direction by the moving device 102, and the moving distance is equivalent to three pixels. Then, a blue light emitting layer 8c is formed every three columns in the main scanning direction.

In this way, the light emitting layer 8c is formed on all the hole injection layers 8b.
Similarly, the mono-color panel can be applied, but the moving distance in the sub-scanning direction when applying the light emitting layer is one pixel, and only the second coating device 110 is necessary for the application of the light emitting layer.

[4-3] Step after Using Coating Device Subsequently, the counter electrode 8d is formed on the substrate 121 on which the light emitting layer 8c is formed, and the light emitting layer 8c and the bank 13 are covered with the counter electrode 8d.
Then, the substrate 121 is cut for each substrate 10 to complete the EL panel 1.

As described above, the EL panel 1 manufactured using the coating apparatus 100 is used as a display panel for various electronic devices.
For example, the display panel 1a of the mobile phone 200 shown in FIG. 15, the display panel 1b of the digital camera 300 shown in FIGS. 16A and 16B, or the display panel 1c of the personal computer 400 shown in FIG. The EL panel 1 can be applied.

  The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

100 coating device 101 work table 102 moving device (nozzle moving unit)
105 Carriage (nozzle moving part)
106 Nozzle head (discharge unit)
168 Nozzle hole (nozzle)
60 Optical sensor unit (transmittance detection unit)
61 projector 62 light receiver 107 supply pipe 108 liquid tank (liquid reservoir)
116 Supply Unit 119 Control Unit 120 Liquid 121 Substrate (Object)
130 Cooling trap (degassing part)
140 Vacuum pump (pressure reducing device, defoaming part)
150 Sealing cap (degassing part)
R1 Panel area (application area)
R2 Margin area (non-target area)

Claims (7)

A liquid reservoir in which liquid is stored;
A discharge section having a nozzle for discharging the liquid;
A supply pipe piped from the liquid storage part to the discharge part;
A nozzle moving unit that moves the discharge unit relative to an object to which the liquid is applied;
A transmittance detector for detecting the light transmittance of the space in which the liquid accumulates in the ejection part; a controller for controlling the nozzle moving part and the transmittance detector;
With
When the control unit determines that the light transmittance detected by the transmittance detection unit exceeds an allowable value, the control unit causes the nozzle moving unit to move the ejection unit to a standby position, and A coating apparatus that performs a process of removing bubbles remaining in the unit.   The control unit, based on the light transmittance detected by the transmittance detection unit, the light transmittance corresponding to the timing when the light transmittance exceeds the allowable value and the liquid cannot be ejected from the nozzle. 2. The coating apparatus according to claim 1, wherein the discharge unit is moved to the standby position until the threshold value reaches a threshold value, and a process of removing bubbles remaining in the discharge unit is performed.   The coating apparatus according to claim 1, wherein the standby position includes a defoaming unit that sucks and removes bubbles in the discharge unit. The transmittance detector is
The coating device according to any one of claims 1 to 3, comprising a projector that emits predetermined light toward a space in the ejection unit, and a light receiver that detects light that has passed through the space. apparatus. The nozzle moving unit moves the ejection unit over a range in which a plurality of application target areas where the liquid is to be applied and non-target areas where the liquid does not need to be applied are alternately arranged. Applying the liquid continuously discharged from the nozzle to the object;
The control unit predicts a timing at which the light transmittance detected by the transmittance detection unit becomes the threshold, and determines that the ejection unit is at a position corresponding to the application target region at the predicted timing. In this case, in the non-target region before the application target region, the discharge unit is moved to the standby position to perform a process of removing bubbles remaining in the discharge unit. The coating apparatus as described in any one. The liquid is supplied from a liquid storage part in which the liquid is stored via a supply pipe, and a discharge part having a nozzle for discharging the liquid is moved relative to the object, and the liquid is applied to the object. Apply,
While applying the liquid to the object, the light transmittance of the space in which the liquid is accumulated in the ejection unit is detected, and whether or not the light transmittance exceeds an allowable value. Judgment
When it is determined that the light transmittance exceeds an allowable value, the defoaming process is performed to move the discharge unit to a standby position and remove bubbles remaining in the discharge unit. .   In the operation of executing the defoaming process, when it is determined that the light transmittance exceeds the allowable value, the light transmittance reaches a threshold value when the coating operation is continued, and the liquid is discharged from the nozzle. The coating method according to claim 6, wherein a timing at which the ejection becomes impossible is predicted, and the ejection unit is moved to the standby position until the timing is reached.

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