JP2013187000A - Functional liquid discharge method, organic el element manufacturing method, organic el device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional liquid discharge method which can apply a coating of a predetermined amount of functional liquid to functional layer formation regions stably, as well as an organic EL element manufacturing method, an organic EL element, and an electronic apparatus for which this method is adopted.SOLUTION: A functional liquid discharge method in the present application example is designed in such a way that, while a discharge head having a plurality of nozzles 52 scans functional layer formation regions A by moving relative thereto a number of times, a functional liquid containing a functional layer formation material is discharged as droplets from a nozzle group including at least two nozzles 52 covering the functional layer formation regions A. At least one of the nozzles 52 out of the nozzle group is unselected, and the same number of nozzles is selected each time a scan is performed.

Description

  The present invention relates to a method for discharging a functional liquid containing a functional layer forming material in a liquid, a method for manufacturing an organic EL (Electro Luminescence) element, an organic EL device, and an electronic apparatus.

In recent years, it has been put into practical use to form various functional layers by industrially applying a so-called ink jet printer technology that prints characters or images by ejecting ink as droplets onto a printing medium such as paper. .
For example, in Patent Document 1, an inkjet head having a plurality of nozzles is scanned relative to a substrate, and ink for forming a colored layer is ejected from the plurality of nozzles to the same pixel region on the substrate. A color filter manufacturing method for manufacturing a color filter by coating is disclosed.
Further, for example, Patent Document 2 discloses a liquid material ejection method in which the combination of nozzle selection patterns for ejecting droplets in a plurality of scans of a plurality of nozzles and a substrate is the same for each film formation region, and this A manufacturing method of a color filter to which a discharging method is applied and a manufacturing method of an organic EL element are disclosed.

JP 2009-122661 A JP 2009-148694 A

According to the ejection methods disclosed in Patent Document 1 and Patent Document 2, a predetermined amount of ink or liquid can be stably applied to a predetermined region. However, if the number of nozzles from which droplets are ejected changes for each scan and for each predetermined region, ejection of droplets ejected from the selected nozzle due to the influence of mechanical or electrical crosstalk between the nozzles When the amount varies or the number of nozzles used for each scan changes, the temperature of the ink jet head may change for each scan, and the amount of discharged droplets may vary.
That is, the film thickness and film shape of the functional layer fluctuate due to such variations in the discharge amount of droplets, and a color filter having desired optical characteristics or an organic EL element having desired electro-optical characteristics can be used as an inkjet head. There has been a problem that it is difficult to manufacture using the material.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] In the functional liquid discharge method according to this application example, the functional layer formation region is moved between a plurality of scans in which an ejection head having a plurality of nozzles is moved relative to the functional layer formation region. A functional liquid discharging method for discharging a functional liquid containing a functional layer forming material as droplets from a nozzle group including at least two nozzles applied to the nozzle, wherein at least one nozzle of the nozzle group is selected as non-selected. The number of nozzles is the same for each scan.

According to this application example, since the number of nozzles selected to eject droplets to the functional layer formation region for each scan is the same, the number of nozzles selected for each scan is different compared to the case where the number of nozzles selected for each scan is different. The mechanical or electrical crosstalk is reduced. In addition, since the amount of energy consumed for ejecting droplets from the nozzle can be made uniform over a plurality of scans, changes in the temperature of the ejection head during scanning are reduced. Therefore, variation in the discharge amount of droplets during scanning is suppressed, a predetermined amount of functional liquid can be stably applied to the functional layer formation region, and a functional layer having stable characteristics can be formed.
In addition, if droplets are ejected using all the nozzle groups applied to the functional layer formation region for each scan, the total amount of functional liquid applied to the functional layer formation region after a plurality of scans exceeds the predetermined amount. There may be a shortage. As a method for solving this problem, for example, it is conceivable to adjust the concentration of the functional layer forming material in the functional liquid. However, it takes time to adjust the concentration.
According to this application example, since at least one nozzle is not selected from the nozzle group applied to the functional layer formation region in scanning, the number of scans for applying a predetermined amount of functional liquid to the functional layer formation region increases. Thus, the same number of nozzles can be selected for each scan.

Application Example 2 In the functional liquid ejection method according to the application example described above, it is preferable to select the same nozzle from the nozzle group for each scan.
According to this method, liquid droplets are ejected using the same nozzle from the nozzle group that covers the functional layer formation region in scanning, so that the liquid droplets between the nozzles are different from when different nozzles are used for each scanning. It is difficult to be affected by variations in the discharge amount. The total amount (predetermined amount) of the applied functional liquid is stabilized between the functional layer forming regions where the same nozzle is applied during scanning.

Application Example 3 In the functional liquid discharge method according to the application example described above, it is preferable that a defective nozzle that does not properly discharge the droplets is the non-selected nozzle.
According to this method, for example, a droplet is not ejected due to clogging of the nozzle, or even if a droplet is ejected, the ejection amount is extremely small or large. Scanning is performed using nozzles that perform normal ejection, excluding defective nozzles that do not land at the position. Therefore, variation in the discharge amount of the droplets can be suppressed and repeated and stable discharge can be realized. In other words, even if a defective nozzle occurs, it is not necessary to stop scanning, so that high productivity can be realized.

Application Example 4 In the functional liquid ejection method according to the application example described above, a nozzle selected from the nozzle group may be changed during the plurality of scans.
According to this method, a nozzle that was not selected in a certain scan can be selected in the next scan. That is, it is possible to prevent clogging from occurring due to fixing of the non-selected nozzles.

Application Example 5 In the functional liquid ejection method according to the application example described above, it is preferable that a partition wall surrounding the functional layer formation region is provided, and a nozzle at the partition wall in the nozzle group is selected.
According to this method, it is possible to land droplets on the partition walls by scanning, and it is possible to reduce the uneven thickness of the functional layer due to the difficulty of spreading the functional liquid on the partition walls.
Further, since the nozzle applied to the partition during scanning is not selected, if the nozzle at the partition is not selected, the non-selected nozzles are continuous. The amount of droplets discharged from selected nozzles adjacent to consecutive non-selected nozzles is likely to vary. Therefore, by selecting the nozzle at the partition wall among the nozzle groups applied to the functional layer formation region in scanning, it is possible to further suppress variations in the droplet discharge amount.

[Application Example 6] A method for manufacturing an organic EL element according to this application example is a method for manufacturing an organic EL element having a functional layer including a light emitting layer in a functional layer formation region on a substrate. Using a functional liquid discharging method, a step of discharging a functional liquid containing a functional layer forming material to the functional layer forming region, and solidifying the discharged functional liquid to form at least one of the functional layers And a process.
According to this application example, an organic EL element having stable electro-optical characteristics can be manufactured.

Application Example 7 In the method of manufacturing an organic EL element according to the application example, the functional liquid containing a light emitting layer forming material is discharged to the functional layer forming region to form the light emitting layer among the functional layers. It is characterized by.
According to this method, an organic EL device having stable light emission characteristics can be manufactured.

Application Example 8 An organic EL device according to this application example includes an organic EL element manufactured using the method for manufacturing an organic EL element described in the application example.
According to this application example, an organic EL device having desired electro-optical characteristics can be provided.

Application Example 9 An electronic apparatus according to this application example includes the organic EL device described in the application example.
According to this application example, it is possible to provide an electronic apparatus including a display device having a good appearance and an organic EL device as a lighting device.

The schematic perspective view which shows the structure of a discharge device. (A) is a perspective view which shows the structure of an ejection head, (b) is a top view which shows the arrangement | positioning state of a nozzle. FIG. 3 is a schematic plan view showing an arrangement of ejection heads in the head unit. The block diagram which shows the control system of a discharge apparatus. The timing chart which shows a drive waveform. The figure explaining the discharge method of the functional liquid of a prior art example. FIG. 3 is a diagram illustrating a functional liquid discharge method according to the first embodiment. FIG. 6 is a diagram illustrating a functional liquid discharge method according to the second embodiment. FIG. 6 is a diagram illustrating a functional liquid discharge method according to a third embodiment. FIG. 6 is a diagram illustrating a functional liquid discharge method according to a fourth embodiment. FIG. 10 is a diagram illustrating a functional liquid discharge method according to a fifth embodiment. 1 is a schematic front view showing an organic EL device. The principal part schematic sectional drawing of an organic electroluminescent apparatus. The flowchart which shows the manufacturing method of an organic electroluminescent apparatus. (A)-(d) is a schematic sectional drawing which shows the manufacturing method of an organic EL element. (E)-(h) is a schematic sectional drawing which shows the manufacturing method of an organic EL element. (A) is a schematic plan view which shows the structure of a color filter board | substrate, (b) is a schematic sectional drawing which shows the structure of a color filter board | substrate.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It is assumed that a part is arranged so as to be in contact with each other and a part is arranged via another component.

(First embodiment)
<Functional liquid discharge device>
First, a discharge device capable of discharging a functional liquid containing a functional layer forming material as droplets onto an object to be discharged will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing the configuration of the discharge device.

  As shown in FIG. 1, the ejection device 10 includes a workpiece moving mechanism 20 that moves a flat workpiece W, which is an object to be ejected, in a main scanning direction (Y-axis direction) as a first direction, and a head unit 9. And a head moving mechanism 30 that moves in the sub-scanning direction (X-axis direction) as a second direction orthogonal to the main scanning direction.

The workpiece moving mechanism 20 includes a pair of guide rails 21, a moving table 22 that moves along the pair of guide rails 21, and a stage on which the workpiece W disposed on the moving table 22 via the rotating mechanism 6 is placed. And 5.
The moving table 22 moves in the main scanning direction (Y-axis direction) by an air slider and a linear motor (not shown) provided inside the guide rail 21. The moving table 22 is provided with an encoder 12 (see FIG. 4) as a timing signal generator.
The encoder 12 reads the scale of a linear scale (not shown) arranged in parallel with the guide rail 21 in accordance with the relative movement of the moving base 22 in the main scanning direction (Y-axis direction), and generates an encoder pulse as a timing signal. Is generated. The arrangement of the encoder 12 is not limited to this. For example, the moving table 22 is configured to move relative to the main scanning direction (Y-axis direction) along the rotation axis, and a drive unit that rotates the rotation axis is provided. In such a case, the encoder 12 may be provided in the drive unit. Examples of the drive unit include a servo motor.
The stage 5 can suck and fix the workpiece W, and the rotation mechanism 6 can accurately align the reference axis in the workpiece W with the main scanning direction (Y-axis direction) and the sub-scanning direction (X-axis direction). ing.
Further, it is possible to turn the workpiece W by, for example, 90 degrees in accordance with the arrangement of the functional layer forming region from which the functional liquid is discharged on the workpiece W.

The head moving mechanism 30 includes a pair of guide rails 31 and a moving table 32 that moves along the pair of guide rails 31. The moving table 32 is provided with a carriage 8 suspended via a rotation mechanism 7.
A head unit 9 on which a plurality of ejection heads 50 (see FIG. 2) is mounted is attached to the carriage 8.
Further, a functional liquid supply mechanism (not shown) for supplying functional liquid to the ejection head 50 and a head driver 48 (see FIG. 4) for performing electrical drive control of the plurality of ejection heads 50 are provided. ing.
The moving table 32 moves the carriage 8 in the sub-scanning direction (X-axis direction) and disposes the head unit 9 against the workpiece W.

In addition to the above configuration, the discharge device 10 includes a maintenance mechanism that performs maintenance such as nozzle clogging of a plurality of discharge heads 50 mounted on the head unit 9 and removal of foreign matters and dirt on the nozzle surface. It is disposed at a position facing the head 50.
Further, a weight measuring mechanism 60 (see FIG. 4) having a measuring instrument such as an electronic balance that receives the functional liquid discharged from each discharge head 50 and measures the weight thereof is provided. And the control part 40 which controls these structures comprehensively is provided. In FIG. 1, the maintenance mechanism and the weight measurement mechanism 60 are not shown.

  FIG. 2 is a schematic view showing the structure of the ejection head. FIG. 4A is a perspective view, and FIG. 4B is a plan view showing a nozzle arrangement state.

  As shown in FIG. 2A, the discharge head 50 is a so-called two-unit type, which includes a functional liquid introduction portion 53 having two connection needles 54, and a head substrate 55 stacked on the introduction portion 53. And a head main body 56 which is disposed on the head substrate 55 and in which a flow path in the head of the functional liquid is formed. The connection needle 54 is connected to the above-described functional liquid supply mechanism (not shown) via a pipe, and supplies the functional liquid to the flow path in the head. The head substrate 55 is provided with two connectors 58 connected to the head driver 48 (see FIG. 4) via a flexible flat cable (not shown).

  The head main body 56 includes a pressurizing unit 57 having a cavity formed of a piezoelectric element as a driving unit, and a nozzle plate 51 in which two nozzle rows 52a and 52b are formed in parallel to each other on the nozzle surface 51a. ing.

  As shown in FIG. 2B, in the two nozzle rows 52a and 52b, a plurality (180) of nozzles 52 are arranged at substantially equal intervals with a pitch P1, and the pitch P2 is shifted by half of the pitch P1. In this state, it is disposed on the nozzle surface 51a. In the present embodiment, the pitch P1 is approximately 141 μm, for example. Accordingly, when viewed from the direction orthogonal to the nozzle row 52c, 360 nozzles 52 are arranged at a nozzle pitch of approximately 70.5 μm. The diameter of the nozzle 52 is approximately 27 μm.

  In the ejection head 50, when a drive signal as an electrical signal is applied from the head driver 48 to the piezoelectric element, the volume of the cavity of the pressurizing unit 57 changes, and the functional liquid filled in the cavity is pressurized by the pumping action. Thus, the functional liquid can be discharged from the nozzle 52 as droplets.

  The driving means in the ejection head 50 is not limited to a piezoelectric element. An electromechanical conversion element that displaces a vibration plate as an actuator by electrostatic adsorption, or an electrothermal conversion element (thermal method) that heats a functional liquid and discharges it as a droplet from the nozzle 52 may be used.

  FIG. 3 is a schematic plan view showing the arrangement of the ejection heads in the head unit. Specifically, it is a view seen from the side facing the workpiece W.

  As shown in FIG. 3, the head unit 9 includes a head plate 9a on which a plurality of ejection heads 50 are disposed. A total of six ejection heads 50, that is, a head group 50 </ b> A composed of three ejection heads 50 and a head group 50 </ b> B composed of three ejection heads 50 are mounted on the head plate 9 a. In the present embodiment, the head R1 (ejection head 50) of the head group 50A and the head R2 (ejection head 50) of the head group 50B eject the same type of functional liquid. The same applies to the other heads G1 and G2, and heads B1 and B2. That is, it has a configuration capable of discharging three different functional liquids.

The drawing width that can be drawn by one ejection head 50 is L _0, and this is the effective length of the nozzle row 52c. Hereinafter, the nozzle row 52 c refers to a configuration including 360 nozzles 52.

The head R1 and the head R2 are arranged so that the nozzle rows 52c adjacent to each other when viewed from the main scanning direction (Y-axis direction) are continuous with one nozzle pitch in the sub-scanning direction (X-axis direction) orthogonal to the main scanning direction. They are arranged in parallel in the scanning direction. Therefore, the effective drawing width L ₁ of the heads R 1 and R 2 that discharge the same type of functional liquid is twice the drawing width L ₀ . Similarly, the heads G1 and G2 and the heads B1 and B2 are arranged in parallel in the main scanning direction (Y-axis direction).

  The number of nozzle rows 52c provided in the ejection head 50 is not limited to two, but may be one. Further, the arrangement of the ejection head 50 in the head unit 9 is not limited to this.

  Next, the control system of the discharge device 10 will be described. FIG. 4 is a block diagram illustrating a control system of the discharge device. As shown in FIG. 4, the control system of the discharge device 10 includes a drive unit 46 having various drivers for driving the discharge head 50, the workpiece moving mechanism 20, the head moving mechanism 30, the weight measuring mechanism 60, and the like, and the drive unit 46. And a control unit 40 that comprehensively controls the discharge device 10 including the control unit 40.

  The drive unit 46 is a moving driver 47 that drives and controls the linear motors of the workpiece moving mechanism 20 and the head moving mechanism 30, a head driver 48 that drives and controls the ejection head 50, and a weight that drives and controls the weight measuring mechanism 60. A measurement driver 49 is provided. In addition, a maintenance driver for driving and controlling the maintenance mechanism is provided, but the illustration is omitted.

  The control unit 40 includes a CPU 41, a ROM 42, a RAM 43, and a P-CON 44, which are connected to each other via a bus 45. A host computer 11 is connected to the P-CON 44. The ROM 42 has a control program area for storing a control program to be processed by the CPU 41, and a control data area for storing control data for performing a drawing operation, a function recovery process, and the like.

  The RAM 43 stores various data such as a drawing data storage unit that stores drawing data for drawing on the workpiece W, and a position data storage unit that stores position data of the workpiece W and the ejection head 50 (actually, the nozzle row 52c). It is used as various work areas for control processing. Various drivers and the like of the drive unit 46 are connected to the P-CON 44, and a logic circuit that complements the functions of the CPU 41 and handles interface signals with peripheral circuits is configured and incorporated. For this reason, the P-CON 44 takes various commands from the host computer 11 as they are or processes them and imports them into the bus 45, and in conjunction with the CPU 41, the data and control signals output from the CPU 41 and the like to the bus 45 are used as they are. Or it processes and outputs to the drive part 46. FIG.

  Then, the CPU 41 inputs various detection signals, various commands, various data, etc. via the P-CON 44 according to the control program in the ROM 42, processes various data, etc. in the RAM 43, and then drives via the P-CON 44. The discharge device 10 as a whole is controlled by outputting various control signals to the unit 46 and the like. For example, the CPU 41 controls the ejection head 50, the work moving mechanism 20, and the head moving mechanism 30 so that the head unit 9 and the work W are arranged to face each other. In synchronism with the relative movement between the head unit 9 and the work W, the head driver 48 discharges the functional liquid as droplets from the plurality of nozzles 52 of each discharge head 50 mounted on the head unit 9 to the work W. Send control signal to. In the present embodiment, discharging the functional liquid in synchronization with the movement of the workpiece W in the Y-axis direction is called main scanning as scanning in the present invention, and the head unit 9 is moved in the X-axis direction with respect to main scanning. This is called sub-scanning. The ejection device 10 of the present embodiment can perform functional liquid ejection by repeating a plurality of times by combining main scanning and sub-scanning. The main scanning is not limited to the movement of the workpiece W in one direction with respect to the ejection head 50, but can be performed by reciprocating the workpiece W.

  The encoder 12 is electrically connected to the head driver 48, and generates an encoder pulse with main scanning. In the main scanning, the moving table 22 is moved at a predetermined moving speed, so that encoder pulses are periodically generated.

  For example, if the moving speed of the moving table 22 in the main scanning is 200 mm / sec and the driving frequency for driving the discharge head 50 (in other words, the discharge timing when discharging droplets continuously) is 20 kHz, The droplet discharge resolution is 10 μm because it is obtained by dividing the moving speed by the drive frequency. That is, it is possible to arrange the droplets on the workpiece W at a pitch of 10 μm. The actual droplet ejection timing is based on a latch signal generated by counting periodically generated encoder pulses.

  The host computer 11 sends control information such as a control program and control data to the ejection device 10. Further, it has a function of an arrangement information generation unit that generates arrangement information as ejection control data for arranging a predetermined amount of functional liquid as droplets for each functional layer formation region on the workpiece W. The arrangement information includes the droplet discharge position in the functional layer formation region (in other words, the relative position between the workpiece W and the nozzle 52), the number of droplets disposed (in other words, the number of discharges for each nozzle 52), and a plurality of main scans. The information on ON / OFF of the nozzle 52, that is, selection / non-selection in the present invention, ejection timing, and the like is represented as a bitmap, for example. The host computer 11 can not only generate the arrangement information but also modify the arrangement information once stored in the RAM 43.

  FIG. 5 is a timing chart showing drive waveforms. As shown in FIG. 5, the piezoelectric element as the driving means disposed corresponding to the plurality of nozzles 52 is in accordance with ON / OFF data (discharge data) for each nozzle 52 latched at the timing of the latch signal LAT. One of the three drive waveforms PL1, PL2 and PL3 is selected and supplied. Then, droplets are ejected from the nozzle 52 at the timing when the drive waveform is supplied. Each drive waveform is designed so that a specified amount of liquid droplets is ejected by being supplied to the piezoelectric element.

  The selection of the drive waveform is performed by control signals CH1 to CH3 that define the supply timing of the drive waveform. That is, the drive waveform PL1 of the first system timing is selected by the control signal CH1, the drive waveform PL2 of the second system timing is selected by the control signal CH2, and the drive waveform PL3 of the third system timing is selected by the control signal CH3. .

In the present embodiment, the piezoelectric elements corresponding to the adjacent nozzles 52 in the functional layer formation region are individually associated with the drive waveform supply timing system (relative order based on the latch signal LAT). It is possible to apply the drive waveform so that the discharge timing does not overlap. A method of applying such a drive waveform to the drive means (piezoelectric element) is called time-division drive. By time-division driving, at least electrical crosstalk is suitably reduced, and variations in ejection characteristics (e.g., droplet ejection amount and ejection speed) between the nozzles 52 due to the crosstalk are relatively relaxed.
Further, since the timing of each system is periodic, the ejection conditions are uniform between the ejection timings, and the droplet ejection amount can be stabilized in the main scanning direction.
In addition, since three drive waveforms PL1, PL2, and PL3 are generated within one cycle of latch signal LAT (within one latch), three drive waveforms PL1, PL2, and PL3 are applied to the same piezoelectric element within one latch. If so, three droplets can be ejected from the same nozzle 52 at different ejection timings.
Furthermore, if three drive waveforms PL1, PL2, and PL3 in one latch are applied to different piezoelectric elements, droplets can be discharged from the three nozzles 52 at different discharge timings. That is, the three nozzles 52 are time-division driven.
Further, in the drive waveforms PL1, PL2 and PL3, by changing the amplitude width (substantially the potential difference from the intermediate potential, that is, the drive voltage) and the gradient of the waveform, the droplets discharged from the nozzle 52 are changed. It is possible to vary the discharge amount. In other words, the droplet discharge amount can be corrected by selecting and applying one of the drive waveforms PL1, PL2 and PL3 having different shapes to the piezoelectric elements of the same nozzle 52.
Hereinafter, applying a drive waveform to the piezoelectric element of the nozzle 52 is expressed as applying a drive waveform to the nozzle 52.

  As described above, in the ejection device 10, assuming that the ejection resolution is about 10 μm, when three drive waveforms PL 1, PL 2, PL 3 are applied to the nozzle 52 used continuously, the ejection timing is changed to about 3 in the main scanning direction. It is possible to discharge droplets with a minimum pitch of 3 μm. That is, the substantial discharge resolution in the time-division driving is 3.3 μm.

Since the drive of the nozzles 52 (piezoelectric elements) in the ejection head 50 is time-division driven as described above, electrical crosstalk associated with overlapping ejection timings between adjacent nozzles is reduced. However, when the same drive waveform is applied to the plurality of nozzles 52 and they are driven, droplets having the same discharge amount are not necessarily discharged from each nozzle 52.
For example, the flow path for supplying the functional liquid filled in the cavity of the pressurizing unit 57 to the nozzle 52 is not the same in the plurality of nozzles 52 constituting the nozzle rows 52a and 52b, but the nozzle 52 in the nozzle rows 52a and 52b. It depends on the position. That is, the discharge amount of droplets may vary for each nozzle 52 depending on the mechanical structure of the discharge head 50.
Further, when the selected nozzle 52, that is, the selected actuator (piezoelectric element) is driven when ejecting droplets to the functional layer forming region in the main scanning, an amount corresponding to the energy given to the actuator (piezoelectric element) is obtained. Heat is generated. Such heat generated by the discharge head 50 is radiated through the head plate 9a, and a part of the heat is used to warm the filled functional liquid. That is, the discharge amount of the liquid droplets discharged from the nozzles 52 varies depending on the temperature of the functional liquid in the discharge head 50 during main scanning. In other words, the amount of droplets ejected from the nozzles 52 varies depending on the difference in electrical load in driving the ejection head 50.

  The inventors have developed a functional liquid ejection method that is less susceptible to the above-described mechanical or electrical variation factors in order to suppress variations in the ejection amount of droplets ejected from the nozzle 52.

<Functional liquid discharge method>
Next, the functional liquid ejection method of the present embodiment will be described with reference to a conventional example and an example.
FIG. 6 is a diagram for explaining a conventional functional liquid discharging method, and FIGS. 7 to 11 are diagrams for explaining a functional liquid discharging method according to the first to fifth embodiments.
The functional liquid ejection method of the present embodiment uses the above-described ejection device 10 and forms a plurality of functional liquid layers on the workpiece W in the X-axis direction (sub-scanning direction) and the Y-axis direction (main scanning direction). A functional liquid is applied. During the main scanning in which the head unit 9 including the ejection head 50 and the workpiece W are relatively moved in the Y-axis direction, the functional liquid is ejected as droplets from the nozzles 52 of the ejection head 50 to the functional layer formation region. Make it land. The functional layer forming region is partitioned on the workpiece W by a partition wall. Moreover, the partition or the surface of the partition has liquid repellency with respect to the functional liquid. The functional layer forming region is subjected to a surface treatment for imparting lyophilic properties in consideration of the wettability of the applied functional liquid.

(Conventional example)
First, an example of a conventional functional liquid discharge method will be described with reference to FIG. As shown in FIG. 6, in the conventional example, the functional liquid is applied from the nozzle 52 of the ejection head 50 to the rectangular functional layer forming region A arranged in a matrix in the X-axis direction and the Y-axis direction on the workpiece W. To do. The functional layer forming region A is arranged with respect to the functional layer forming region A so that the longitudinal direction thereof is arranged along the X axis direction, and the nozzle rows 52a and 52b are also extended in the X axis direction. Yes.
In order to make the following description easy to understand, each nozzle 52 of the nozzle rows 52a and 52b is referred to with a reference numeral (52n1 to 52n14). In addition, a plurality of main scans are also referred to with symbols (SC1 to SC7).

Among the nozzle rows 52a and 52b, the functional liquid is ejected as droplets from the plurality of nozzles 52 (nozzle group) applied to the functional layer formation region A by main scanning in the Y-axis direction to the functional layer formation region A. In FIG. 6, the droplets that have landed on the functional layer formation region A are indicated by hatched circles, and the case where the droplets are not ejected is indicated by an imaginary circle without hatching. Since the landed liquid droplets wet and spread in the functional layer formation region A, only the landed state of the liquid droplets discharged for each main scanning is shown. In addition, it shows how to discharge a droplet, and the landing shape (circular shape) and the landing diameter (size) of the droplet are not limited to this.
Specifically, for example, six main scans SC1 to SC6 are performed from five nozzles 52 of reference numeral 52n2 to reference numeral 52n6 which are applied to the functional layer formation area A in the main scan, and a total of 28 droplets are dropped into the functional layer formation area A. To land on. In the drawing range (dischargeable range) of the discharge head 50, a total of 28 droplets are similarly discharged from the nozzles 52n9 to 52n13 to the functional layer forming region A adjacent in the X-axis direction. The nozzles 52n1, 52n7, 52n8, and 52n14 applied to the partition in the main scanning are not selected.
In the main scans SC1 to SC5, the five nozzles 52 that are respectively applied to the functional layer formation region A are selected and liquid droplets are ejected, so that five droplets land on the functional layer formation region A in one main scan. To do. A total of 25 droplets are ejected to the functional layer formation region A by five main scans. In the sixth main scan SC6, among the five nozzles 52 applied to the functional layer formation region A, for example, the three nozzles 52n3 to 52n5 are selected, and three droplets land on the functional layer formation region A. . In the main scan up to the fifth time, all the nozzles 52 applied to the functional layer formation region A are selected and droplets are ejected. In the sixth main scan, three of the nozzle groups applied to the functional layer formation region A are selected. Only one nozzle 52 is selected and a droplet is ejected.

Accordingly, the number of nozzles selected in the main scan SC6 is smaller than those in the other main scans SC1 to SC5. Therefore, compared to the case where all the five nozzles 52 are selected and droplets are ejected, the functional layer forming region A is selected. The state of mechanical or electrical crosstalk between the applied nozzles 52 changes. Therefore, there is a possibility that the ejection amount of the droplets ejected in the main scan SC6 varies as compared with the other main scans SC1 to SC5. More specifically, since the nozzles 52n2 and 52n6 selected so far in the sixth main scan SC6 are not selected, the nozzles 52n3 and 52n5 adjacent to the non-selected nozzle 52 are selected. There is a risk that the discharge amount of the liquid droplets discharged from the nozzle will increase or decrease compared to the previous five main scans. As described above, electrical crosstalk between adjacent nozzles 52 can be alleviated by selecting different drive waveforms from the three drive waveforms PL1, PL2, and PL3. However, if the width of the functional layer formation region A in the Y-axis direction becomes narrower, it is necessary to land the liquid droplets accurately in order to reliably apply the functional liquid to the functional layer formation region A, and the nozzle 52 that discharges the liquid droplets. It is preferable to select the same drive waveform. In other words, there is a problem that it becomes difficult to select a different driving waveform in which the landing position of the droplet is shifted in the Y-axis direction.
In addition, since the number of nozzles selected for the sixth main scan SC6 is reduced, the amount of heat generated by the actuator (piezoelectric element) of the ejection head 50 may be reduced, and the amount of ejected droplets may vary.
That is, even when 28 droplets are ejected to one functional layer formation region A by six main scans, the ejection amount of the droplets ejected from the selected nozzle 52 varies, thereby causing a predetermined amount of functional liquid to be ejected. Is difficult to apply to each functional layer forming region A in a quantitatively stable state.

  The embodiment described below shows an example in which 28 droplets are ejected and applied to the functional layer forming region A in the same manner as in the conventional example in order to facilitate comparison with the conventional example.

Example 1
With reference to FIG. 7, the functional liquid discharging method of the first embodiment will be described. The functional liquid ejection method of the first embodiment is different from the conventional example in that one nozzle 52 is not selected from the five nozzles 52 applied to the functional layer formation region A in the main scanning, and droplets are discharged from the remaining four nozzles 52. Discharge. The number of nozzles selected for each main scan is the same, and the selected nozzles are also the same.

  Specifically, as shown in FIG. 7, among the five nozzles 52 applied to the functional layer formation region A, four nozzles 52n2, 52n3, 52n5, 52n6 are selected, and the approximate center of the functional layer formation region A is relatively Therefore, the nozzle 52n4 that passes therethrough is not selected. Four droplets are ejected and landed on the functional layer forming region A by one main scanning. As described above, since it is necessary to land a total of 28 droplets, seven main scans SC1 to SC7 are performed. Similarly, in the functional layer forming region A adjacent in the X-axis direction, the nozzles 52n11 are not selected and the remaining four nozzles 52n9, 52n10, 52n12, 52n13 are selected, and droplets are ejected for each main scan.

  According to the functional liquid ejection method of the first embodiment, the number of main scans is increased by one compared to the conventional example, but the number of nozzles selected for each main scan is the same, and the selected nozzles 52 are the same. It is. Further, in the functional layer formation region A where the same functional liquid is discharged, the nozzles 52 selected (hereinafter also referred to as a selection pattern of the nozzles 52) are the same. Accordingly, the state of mechanical or electrical cross stroke between the nozzles in each main scan becomes constant, and the heat generation amount of the discharge head 50 becomes constant. The variation can be suppressed as compared with the conventional example. Therefore, a predetermined amount (corresponding to 28 droplets) of the functional liquid can be stably applied to each functional layer forming region A.

(Example 2)
Next, a functional liquid discharging method according to the second embodiment will be described with reference to FIG. In the second embodiment, the selection pattern of the nozzles 52 is changed while the same number of nozzles are selected for each main scan as in the first embodiment. In the following description, reference numeral A1 is given to the functional layer formation region A located in the upper part in the figure, and reference numeral A2 is given to the functional layer formation region A located in the lower part. Of course, the functional layer formation region A1 and the functional layer formation region A2 have the same shape and size.

  Specifically, as shown in FIG. 8, nozzles 52n2, 52n3, 52n5, and 52n6 are selected from the nozzle group applied to the functional layer formation region A1, and the nozzle 52n4 is not selected. In addition, the nozzles 52n9, 52n10, 52n11, and 52n13 are selected from the nozzle group applied to the functional layer formation region A2, and the main scanning SC1 to SC7 is performed seven times with the nozzle 52n12 not selected. In each of the functional layer formation regions A1 and A2, 28 droplets are discharged. The number of nozzles selected for each main scan is the same for all functional layer formation regions A1 and A2. The selection pattern of the nozzles 52 in the functional layer formation region A1 for each main scan is the same. The selection pattern of the nozzles 52 in the functional layer formation region A2 for each main scan is the same. On the other hand, the nozzle 52 selection pattern in the functional layer formation region A1 is different from the nozzle 52 selection pattern in the functional layer formation region A2.

According to the functional liquid ejection method of the second embodiment, droplets are not ejected due to, for example, clogging of the nozzles 52 in the nozzle groups applied to the functional layer formation regions A1 and A2 by main scanning, or droplets are ejected. If there is a defective nozzle such that the discharge amount is extremely small or large, or even if a droplet is ejected, it does not land at a predetermined position due to flight bending, the main scanning is performed with the defective nozzle not selected. be able to. For example, in the second embodiment, it may be considered that the nozzle 52n12 is a defective nozzle and the nozzle 52n11 is selected instead of the defective nozzle.
The number of nozzles selected for each main scan is the same as that in the first embodiment, and droplets are ejected from the nozzles 52 of the same selection pattern to the functional layer formation region A arranged in the main scan direction (Y-axis direction). The That is, it is possible to discharge droplets while suppressing variation in the discharge amount to at least the functional layer formation region A arranged in the main scanning direction.
In addition, the defective nozzle can be a non-selected nozzle, and even if a defective nozzle occurs, it is possible to respond without stopping the main scanning, so that high productivity can be realized in discharging the functional liquid.
For convenience of explanation, FIG. 8 shows an example in which the functional layer formation region A1 and the functional layer formation region A2 to which the same functional liquid is applied are arranged adjacent to each other in the X-axis direction. In the functional layer forming region A where the defective nozzle is applied by the main scanning, the defective nozzle may be the non-selected nozzle 52.

(Example 3)
Next, with reference to FIG. 9, the functional liquid discharge method of Example 3 will be described. The third embodiment is different from the first embodiment in that the selection pattern of the nozzles 52 is changed during a plurality of main scans while the same number of nozzles are selected for each main scan.

  Specifically, as shown in FIG. 9, in the first main scan SC <b> 1, for example, the nozzle 52 n <b> 2 located at the end of the nozzle group applied to the functional layer formation region A <b> 1 is not selected and droplets are discharged from the remaining four nozzles 52. Is discharged. Thereafter, in the second to seventh main scans SC <b> 2 to SC <b> 7, the nozzles 52 are not selected in order from the end of the nozzle group, and droplets are ejected. Of the seven main scans, the selection patterns of the nozzles 52 in the first main scan SC1 and the sixth main scan SC6, the second main scan SC2 and the seventh main scan SC7 are the same, and the third to fifth times. The main scanning SC3 to SC5 have different nozzle 52 selection patterns.

  Such a difference in the selection pattern of the nozzles 52 may be similarly applied to the other functional layer formation region A2, or, as shown in FIG. 9, the functional layer formation region A1 and the functional layer formation region for each main scan. It may be different from A2.

According to the functional liquid ejection method of the third embodiment, since the same number of nozzles are selected for each main scan, the electrical load related to the driving of the ejection head 50 is performed a plurality of times (seven times). The liquid droplets can be discharged while being uniformed and suppressing variations in the discharge amount from the nozzle group applied to the functional layer formation regions A1 and A2.
Further, since the non-selected nozzles 52 in the nozzle group are changed during a plurality of main scans, the functional liquid in the nozzles 52 is dried and clogged as compared with the case where the non-selected nozzles 52 are fixed. Such as causing problems.

  From the viewpoint of reducing clogging of the nozzles 52, it is desirable to change the non-selected nozzles 52 in order (periodically) corresponding to the arrangement of the nozzles 52 for each main scan as described above. Note that the selection pattern of the nozzles 52 may not be changed in the main scanning before and after, and the same selection pattern may be repeated as long as the number of main scannings exceeds the number of nozzles in the nozzle group. In other words, the plurality of nozzles 52 constituting the nozzle group applied to the functional layer formation region A may be deselected at least once out of the plurality of main scans.

Example 4
Next, with reference to FIG. 10, a functional liquid discharge method according to the fourth embodiment will be described. The fourth embodiment is configured to always select the nozzle 52 located at the partition wall in the X-axis direction from the nozzle group applied to the functional layer formation region A, as compared with the third embodiment.

  In the third embodiment, for example, as shown in FIG. 9, in the main scanning SC5, the four nozzles 52 from the nozzle 52n6 applied to the functional layer formation region A1 to the nozzle 52n9 applied to the functional layer formation region A2 are continuously unselected. . The two nozzles 52n7 and 52n8 applied to the partition walls are naturally not selected. Therefore, if at least one of the nozzles 52 at the partition wall in the X-axis direction of the functional layer formation regions A1 and A2 is not selected, the non-selected nozzle 52 Can occur at least three consecutive. The droplets ejected from the selected nozzle 52 adjacent to the consecutive non-selected nozzles 52 are easily affected by mechanical or electrical crosstalk in the structure of the ejection head 50, and the ejection amount may vary. .

  Therefore, in the fourth embodiment, as shown in FIG. 10, the nozzle 52 positioned at the partition wall in the X-axis direction is always selected from the nozzle groups applied to the functional layer formation regions A1 and A2, and one of the remaining nozzles 52 is selected. Not selected. As a result, the non-selected nozzles 52 do not continue every main scan except for the nozzles 52 that are applied to the partition walls. Therefore, it is possible to suppress variations in the discharge amount of liquid droplets due to the continuous non-selected nozzles 52. Further, since the nozzle 52 at the partition wall is always selected, it is possible to reliably spread the landed droplets to the partition wall and reduce coating unevenness. Of course, since the number of nozzles selected for each main scan is the same, variations in the discharge amount of droplets due to an electrical load related to driving of the discharge head 50 are suppressed.

(Example 5)
Next, a functional liquid discharging method according to the fifth embodiment will be described with reference to FIG. Example 5 is a combination of Example 1 or Example 2 and Example 4.
Specifically, as shown in FIG. 11, the nozzle 52n4 is not selected from the nozzle group applied to the functional layer formation region A1, and droplets are ejected from the remaining nozzles 52. Further, the nozzle 52 at the partition wall in the X-axis direction is always selected from the nozzle group applied to the functional layer formation region A2, and one nozzle 52 is not selected for each main scan from the remaining nozzles 52.
According to the functional liquid ejection method of the fifth embodiment, while obtaining the effect of the fourth embodiment, when a defective nozzle occurs, the defective nozzle is detected in the functional layer forming region A where the defective nozzle is applied by the main scanning. It can be handled as a non-selected nozzle 52. That is, it is possible to suppress variations in the discharge amount of droplets and realize high productivity.

In summary, the functional liquid ejection method of the present embodiment ejects liquid droplets from the remaining four selected nozzles 52 without selecting one of the nozzle groups applied to the functional layer formation region A by main scanning. The number of nozzles selected for each main scan is the same, and the number of main scans is set so that a predetermined amount of functional liquid is applied to each functional layer forming region A.
According to this, it is possible to make it difficult to be affected by mechanical or electrical crosstalk between the nozzles of the nozzle group applied to the functional layer forming region A in the main scanning. Furthermore, since the same number of nozzles are selected for each main scan, the electrical load in driving the ejection head 50 can be made uniform over a plurality of main scans, and variations in droplet discharge amount can be suppressed. . That is, since a predetermined amount of functional liquid is stably applied to each functional layer forming region A, a functional layer having a stable film thickness and film shape can be formed after the applied functional liquid is solidified. .

  If the number of droplets (the number of droplets) when a predetermined amount of the functional liquid to be applied to the functional layer formation region A is discharged as droplets is not divisible by the number of main scans, that is, an integer, it is divisible by an integer. The discharge number (the number of droplets) is adjusted. As an adjustment method, for example, a droplet discharge amount is corrected in advance so as to have a desired discharge number. The number of droplets ejected (number of droplets) can also be adjusted by adjusting the concentration of the functional layer forming material (solid content) in the functional liquid.

  The functional liquid ejection method of the present invention is not limited to Examples 1 to 5 of the above embodiment, and the above-described droplet arrangement information (bitmap) by appropriately combining Examples 1 to 4 ) May be configured.

(Second Embodiment)
<Organic EL device>
Next, an organic EL device having an organic EL element manufactured by applying the organic EL (electroluminescence) element manufacturing method of the present embodiment will be described with reference to FIGS. FIG. 12 is a schematic front view showing the organic EL device, and FIG. 13 is a schematic cross-sectional view of the main part of the organic EL device.

  As shown in FIG. 12, the organic EL device 100 according to this embodiment includes an element substrate 101 including R (red), G (green), B (blue), and three-color light emitting pixels 107, and an element substrate 101. And a sealing substrate 102 arranged to face each other at a predetermined interval. The sealing substrate 102 is bonded to the element substrate 101 by using a sealing agent having high airtightness so as to seal the light emitting region 106 in which the plurality of light emitting pixels 107 are provided.

  The light-emitting pixel 107 includes an organic EL element 112 (see FIG. 13) as a light-emitting element to be described later, and a so-called stripe method in which the light-emitting pixels 107 that can emit light of the same color are arranged in the vertical direction in the drawing. It has become. Actually, the light emitting pixels 107 are minute and are enlarged for convenience of illustration.

  The element substrate 101 is slightly larger than the sealing substrate 102, and two scanning line driving circuit portions 103 for driving the light emitting pixels 107 and one data line driving circuit portion 104 are provided in a portion protruding in a frame shape. ing. The scanning line driving circuit unit 103 and the data line driving circuit unit 104 may be mounted on the element substrate 101 as an IC in which an electric circuit is integrated, for example, or the scanning line driving circuit unit 103 and the data line driving circuit unit 104 may be mounted. It may be formed directly on the surface of the element substrate 101.

  A relay substrate 105 for connecting the scanning line driving circuit unit 103 or the data line driving circuit unit 104 and an external driving circuit is mounted on the terminal portion 101 a of the element substrate 101. For example, a flexible circuit board can be used as the relay board 105.

  As shown in FIG. 13, in the organic EL device 100, the organic EL element 112 includes an anode 131 as a pixel electrode, a partition wall 133 that partitions the anode 131, and a light emitting layer made of an organic film formed on the anode 131. And a functional layer 132 including the functional layer 132. In addition, a cathode 134 as a common electrode is formed so as to face the anode 131 with the functional layer 132 interposed therebetween.

  The partition wall 133 is made of a photosensitive resin having an insulating property such as phenol or polyimide, and is provided so as to partially cover the periphery of the anode 131 constituting the light emitting pixel 107 and partition the plurality of anodes 131.

  The anode 131 is connected to one of the three terminals of the TFT element 108 formed on the element substrate 101. For example, ITO (Indium Tin Oxide), which is a transparent electrode material, is formed to a thickness of about 100 nm. Electrode.

  The cathode 134 is formed of a metal material having light reflectivity such as Al or Ag, or an alloy of the metal material and another metal (for example, Mg).

  The organic EL device 100 according to the present embodiment has a so-called bottom emission type structure, in which a drive current is passed between the anode 131 and the cathode 134 and light emitted from the functional layer 132 is reflected by the cathode 134 so as to be an element. Remove from the substrate 101 side. Therefore, a transparent substrate such as glass is used for the element substrate 101. As the sealing substrate 102, either a transparent substrate or an opaque substrate can be used. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.

The element substrate 101 is provided with a circuit unit 111 for driving the organic EL element 112. That is, a base protective layer 121 mainly composed of SiO ₂ is formed on the surface of the element substrate 101 as a base, and a semiconductor layer 122 made of, for example, polysilicon is formed thereon. A gate insulating film 123 mainly composed of SiO ₂ and / or SiN is formed on the surface of the semiconductor layer 122.

In the semiconductor layer 122, a region overlapping with the gate electrode 126 with the gate insulating film 123 interposed therebetween is a channel region 122a. The gate electrode 126 is a part of a scanning line (not shown). On the other hand, a first interlayer insulating layer 127 mainly composed of SiO ₂ is formed on the surface of the gate insulating film 123 covering the semiconductor layer 122 and having the gate electrode 126 formed thereon.

  In the semiconductor layer 122, a low concentration source region and a high concentration source region 122c are provided on the source side of the channel region 122a, while a low concentration drain region and a high concentration drain region 122b are provided on the drain side of the channel region 122a. Are provided to form a so-called LDD (Light Doped Drain) structure. Among these, the high-concentration source region 122c is connected to the source electrode 125 through a contact hole 125a that opens over the gate insulating film 123 and the first interlayer insulating layer 127. The source electrode 125 is configured as a part of a power supply line (not shown). On the other hand, the high-concentration drain region 122b is connected to the drain electrode 124 formed of the same layer as the source electrode 125 through a contact hole 124a opened over the gate insulating film 123 and the first interlayer insulating layer 127.

  A planarization layer 128 is formed on the first interlayer insulating layer 127 on which the source electrode 125 and the drain electrode 124 are formed. The planarization layer 128 is formed of a heat-resistant insulating resin such as acrylic or polyimide, and is formed to eliminate surface irregularities due to the TFT element 108, the source electrode 125, the drain electrode 124, and the like. Are known.

  An anode 131 is formed on the surface of the planarization layer 128 and is connected to the drain electrode 124 through a contact hole 128 a provided in the planarization layer 128. That is, the anode 131 is connected to the high concentration drain region 122 b of the semiconductor layer 122 through the drain electrode 124. The cathode 134 is connected to GND. Therefore, the TFT element 108 as a switching element controls the drive current supplied from the power supply line to the anode 131 and flowing between the cathode 134. Thereby, the circuit unit 111 emits light from the desired organic EL element 112 to enable color display.

  The configuration of the circuit unit 111 that drives the organic EL element 112 is not limited to this.

  The functional layer 132 includes a plurality of thin film layers including a hole injection layer made of an organic film, an intermediate layer, and a light emitting layer, and is stacked in this order from the anode 131 side. In this embodiment, these thin film layers are formed using a droplet discharge method (inkjet method).

  As a material for the hole injection layer, for example, a mixture (PEDOT / PSS) obtained by adding polystyrene sulfonate (PSS) as a dopant to a polythiophene derivative such as polyethylenedioxythiophene (PEDOT), polystyrene, polypyrrole, polyaniline, polyacetylene, or the like. Or a derivative thereof may be used.

  The intermediate layer is provided between the hole injection layer and the light-emitting layer, improves the hole transportability (injection) to the light-emitting layer, and suppresses the penetration of electrons from the light-emitting layer into the hole injection layer. Is provided to do. That is, the efficiency of light emission by the combination of holes and electrons in the light emitting layer is improved. Examples of the material for the intermediate layer include those containing a triphenylamine polymer having a good hole transport property.

  Examples of the material of the light emitting layer include polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyphenylene derivatives (PP), polyparaphenylene derivatives (PPP), polyvinyl which can emit red, green, and blue light. Polythiophenylene derivatives such as carbazole (PVK) and PEDOT, polymethylphenylenesilane (PMPS), and the like can be used. In addition, polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, nile red, coumarin 6, quinacrine, etc. A low molecular material may be doped.

  The element substrate 101 having such an organic EL element 112 is solid-sealed with the sealing substrate 102 without a gap through a sealing layer 135 using a thermosetting epoxy resin or the like as a sealing member.

  The organic EL device 100 of the present embodiment is manufactured using a method for manufacturing the organic EL element 112 described later, and the light emitting layer has a substantially constant film thickness and a stable film shape (cross-sectional shape). In the functional layers 132R, 132G, and 132B that can obtain different emission colors, desired emission characteristics can be obtained.

  The organic EL device 100 of the present embodiment is not limited to the bottom emission type. For example, the anode 131 is formed using a light-reflective conductive material, and the cathode 134 as a common electrode is formed using a transparent conductive material. A top emission type structure in which light emission from the organic EL element 112 is reflected by the anode 131 and extracted from the sealing substrate 102 side may be employed. In the case of a top emission type, a color filter corresponding to the emission color of the organic EL element 112 may be provided on the sealing substrate 102 side. Further, when a color filter is provided on the sealing substrate 102 side, white light emission may be obtained from the organic EL element 112.

<Method for producing organic EL element>
Next, a method for manufacturing an organic EL device to which the method for manufacturing an organic EL element of the present embodiment is applied will be described with reference to FIGS. FIG. 14 is a flowchart illustrating a method for manufacturing an organic EL device, and FIGS. 15A to 15D and 16E to 16H are schematic cross-sectional views illustrating a method for manufacturing an organic EL element.

  As shown in FIG. 14, the manufacturing method of the organic EL device 100 of this embodiment includes a partition wall forming step (Step S1), a surface treatment step (Step S2) for performing a surface treatment on the substrate on which the partition wall is formed, Element substrate on which hole injection layer forming step (step S3), intermediate layer forming step (step S4), light emitting layer forming step (step S5), cathode forming step (step S6), and organic EL element 112 are formed At least a sealing substrate bonding step (step S7) for bonding 101 and the sealing substrate 102 to each other. A known manufacturing method may be used for the step of forming the circuit portion 111 (see FIG. 13) on the element substrate 101 and the step of forming the anode 131 electrically connected to the circuit portion 111. In this embodiment, Detailed description is omitted. Accordingly, the circuit portion 111 is not shown in FIGS. 15A to 15D and FIGS. 16E to 16H.

  Step S1 in FIG. 14 is a partition forming process. In step S <b> 1, as shown in FIG. 15A, the partition wall 133 is formed so as to cover the anode 131 and partition the anode 131. As a forming method, for example, a photosensitive phenol resin or polyimide resin is applied to the surface of the element substrate 101 on which the anode 131 is formed with a thickness of about 1 μm to 3 μm. Examples of the coating method include a transfer method and a slit coating method. Then, exposure is performed using a mask corresponding to the shape of the light emitting pixel 107 and development is performed, so that the partition wall 133 is formed. Hereinafter, the region of the light emitting pixel 107 partitioned by the partition wall 133 is referred to as a functional layer formation region A. Then, the process proceeds to step S2.

Step S2 in FIG. 14 is a surface treatment process. In step S2, lyophilic treatment and lyophobic treatment are performed on the surface of the element substrate 101 on which the partition wall 133 is formed. First, plasma processing using oxygen as a processing gas is performed, and lyophilic processing is performed on the surface of the anode 131 made mainly of an inorganic material. Next, plasma treatment is performed using a fluorine-based gas such as CF ₄ as a treatment gas, and fluorine is introduced into the surface of the partition wall 133 made of an organic material to perform a liquid repellent treatment.
Note that the formation of the partition 133 having liquid repellency is not limited to this. For example, a liquid repellent material may be transferred to the top of the partition wall 133 to form a liquid repellent layer, or the photosensitive resin itself may contain a liquid repellent material to form the partition wall 133. Then, the process proceeds to step S3.

Step S3 in FIG. 14 is a hole injection layer forming step. In step S3, first, as shown in FIG. 15B, the functional liquid 70 containing the hole injection layer forming material is applied to the functional layer forming region A. The functional liquid 70 contains, for example, diethylene glycol and water (pure water) as a solvent, and contains about 0.5% by weight of PEDOT / PSS as a hole injection layer forming material. The ratio of the solvent is adjusted so that the viscosity is about 20 mPa · s or less.
As a method of applying the functional liquid 70, the ejection device 10 that can eject the functional liquid (ink) described in the first embodiment from the nozzles 52 of the ejection head 50 is used. The functional head 70 is ejected from the ejection head 50 with the ejection head 50 and the element substrate 101 being the workpiece W facing each other. The discharged functional liquid 70 lands on the anode 131 that has been treated as a lyophilic liquid droplet and spreads out. Further, a required amount corresponding to the area of the functional layer formation region A was discharged as droplets so that the thickness of the hole injection layer after drying was about 50 nm to 70 nm. Then, the process proceeds to the drying process.

  In the drying process, the element substrate 101 is heated by a method such as lamp annealing to dry and remove the solvent component of the functional liquid 70, and the anode 131 in the functional layer formation region A as shown in FIG. A hole injection layer 132a is formed thereon. In the present embodiment, the hole injection layer 132a made of the same material is formed in each functional layer formation region A. However, the material of the hole injection layer 132a corresponding to the light emitting layer to be formed later is set for each emission color. You may change it. Then, the process proceeds to step S4.

Step S4 in FIG. 14 is an intermediate layer forming process. In step S4, as shown in FIG. 15D, the functional liquid 80 containing the intermediate layer forming material is applied to the functional layer forming region A.
As the functional liquid 80, for example, a liquid containing cyclohexylbenzene as a solvent and containing about 0.1% by weight of the above-mentioned triphenylamine polymer as an intermediate layer forming material was used. The viscosity is approximately 6 mPa · s.
As a method of applying the functional liquid 80, the ejection device 10 of the first embodiment is used as in the case of applying the functional liquid 70. A necessary amount corresponding to the area of the functional layer formation region A was discharged as droplets so that the film thickness of the intermediate layer after drying was approximately 10 nm to 20 nm. And it progresses to a drying process.

  In the drying step, the element substrate 101 is heated by a method such as lamp annealing to dry and remove the solvent component of the functional liquid 80, and as shown in FIG. An intermediate layer 132c is formed on the injection layer 132a. Then, the process proceeds to step S5.

Step S5 in FIG. 14 is a light emitting layer forming step. In step S5, as shown in FIG. 16F, functional liquids 90R, 90G, and 90B containing the light emitting layer forming material are applied to the corresponding functional layer forming regions A.
The functional liquids 90R, 90G, and 90B include, for example, cyclohexylbenzene as a solvent and 0.7% by weight of PF as a light emitting layer forming material. The viscosity is approximately 14 mPa · s.
In the method of applying the functional liquids 90R, 90G, and 90B, the discharge device 10 according to the first embodiment is used, and different discharge heads 50 are filled and discharged.
In forming the light emitting layer, the functional liquid discharging method according to the first embodiment that can discharge the functional liquids 90R, 90G, and 90B to the functional layer formation region A without causing unevenness and stably discharge the required amount was used. . That is, at least one nozzle 52 out of the nozzle group applied to the functional layer formation region A by main scanning was not selected and droplets were ejected from the remaining nozzles 52. The non-selected nozzles 52 and the number of main scans are set so that the same number of nozzles are selected for each main scan. Further, a necessary amount corresponding to the area of the functional layer formation region A was discharged as droplets so that the thickness of the light emitting layer after drying was approximately 50 nm to 100 nm. And it progresses to a drying process.

  The drying process of the discharged functional liquids 90R, 90G, and 90B in the present embodiment uses a reduced-pressure drying method that can dry the solvent component relatively uniformly as compared with general heat drying. A necessary amount of functional liquids 90R, 90G, and 90B are uniformly applied to the functional layer forming region A. Therefore, as shown in FIG. 16G, the light emitting layers 132r, 132g, and 132b formed after drying have a substantially constant film thickness and a stable film shape (cross-sectional shape) for each functional layer formation region A. Then, the process proceeds to step S6.

Step S6 in FIG. 14 is a cathode forming step. In step S6, as shown in FIG. 16H, the cathode 134 is formed so as to cover the partition wall 133 and the functional layers 132R, 132G, and 132B. Thereby, the organic EL element 112 is configured.
As the material of the cathode 134, aluminum (Al), an alloy of silver (Ag) and magnesium (Mg), or the like is used. A Ca, Ba, or LiF film having a small work function may be formed on the side close to the functional layers 132R, 132G, and 132B. A protective layer such as SiO ₂ or SiN may be laminated on the cathode 134. In this way, oxidation of the cathode 134 can be prevented. Examples of the method for forming the cathode 134 include vapor deposition, sputtering, and CVD. In particular, the vapor deposition method is preferable in that the functional layers 132R, 132G, and 132B can be prevented from being damaged by heat. Up to here, the manufacturing process of the organic EL element 112 is shown. Then, the process proceeds to step S7.

  Step S7 in FIG. 14 is a sealing substrate bonding step. In step S7, the sealing layer 135 is applied to the element substrate 101 on which the organic EL element 112 is formed, and is solid-sealed with no gap from the sealing substrate 102 (see FIG. 13). Furthermore, it is desirable to provide and bond an adhesive layer that prevents entry of moisture, oxygen, and the like in the outer peripheral region of the sealing substrate 102.

According to the manufacturing method of the organic EL element 112 as described above, the functional layers 132R, 132G, and 132B formed by the droplet discharge method have reduced film formation unevenness, and each has a substantially constant film thickness and a stable film. The light-emitting layers 132r, 132g, and 132b have a shape (cross-sectional shape). Accordingly, it is possible to manufacture the organic EL element 112 in which luminance unevenness due to film formation unevenness is reduced.
The functional liquid ejection method of the above embodiment is not only applied to the application of the functional liquids 90R, 90G, and 90B including the light emitting layer forming material, and of course, the functional liquid 70 including the hole injection layer forming material and the intermediate liquid. The present invention can also be applied to the application of the functional liquid 80 including the layer forming material.

  The organic EL device 100 including the organic EL element 112 that can produce different light emission manufactured in this manner realizes desired light emission characteristics and enables a good-looking color display.

<Electronic equipment>
The organic EL device 100 manufactured using the method for manufacturing the organic EL element 112 of the present invention can be suitably used as a display unit of various electronic devices.
Examples of electronic devices include portable information terminals such as mobile phones, personal computers, PDAs and POS, digital cameras, digital video cameras, car navigation systems, televisions, HMDs (head-mounted displays), HUDs (head-up displays), and the like. be able to.
Further, the organic EL device 100 may be used not only as a display unit, but also as an illumination device for an electronic device, for example, with the organic EL element 112 configured to obtain white light emission.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The technical scope of the present invention also includes a method, a method for manufacturing an organic EL element, and an organic EL device and an electronic apparatus to which the organic EL element manufactured using the method for manufacturing the organic EL element is applied. Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

  (Modification 1) The method of discharging the functional liquid according to the above embodiment is not limited to the method for manufacturing the organic EL element 112. FIG. 17A is a schematic plan view showing the configuration of the color filter substrate, and FIG. 17B is a schematic sectional view showing the structure of the color filter substrate. As shown in FIG. 17, the color filter substrate 200 includes a transparent base material 201 such as glass, a partition wall 202 formed on the base material 201, and a red ( Colored layers 203R, 203G, and 203B corresponding to the respective colors of R), green (G), and blue (B) are provided. Therefore, the functional liquid ejection method of the present embodiment can also be applied when a functional liquid containing a colored layer forming material prepared for each color is applied to the functional layer forming region. Thereby, the color filter substrate 200 provided with the colored layers 203R, 203G, and 203B having a desired film thickness and film shape can be manufactured.

  (Modification 2) In the functional liquid ejection method of the above embodiment, the nozzle row 52a is parallel to the longitudinal direction (X-axis direction) of the rectangular functional layer forming region A arranged in a matrix on the workpiece W. , 52b (discharge head 50) is disposed, but is not limited thereto. For example, the nozzle rows 52a and 52b may be tilted so as to intersect the longitudinal direction (X-axis direction) of the functional layer formation region A. According to this, the substantial nozzle pitch in the main scanning can be further narrowed to cause the droplets to land. In other words, even if the area of the functional layer formation region A is reduced, the number of nozzles applied to the functional layer formation region A can be increased, and the functional liquid ejection method of the present invention can be easily applied. If the number of nozzles applied to the functional layer formation region A in the main scanning is at least two, the functional liquid ejection method of the present invention can be applied.

  (Modification 3) In the functional liquid ejection method of the above embodiment, the number of liquid droplets to be landed in the main scanning direction (Y-axis direction) of the functional layer forming region A in one main scanning is not limited to one. . A plurality of droplets may be discharged at different discharge timings. According to this, the number of main scans for applying a predetermined amount of functional liquid to the functional layer forming region A can be reduced.

  (Modification 4) In the functional liquid ejection method of the above embodiment, the shape and arrangement of the functional layer formation region A are not limited to this. For example, the present invention can be applied not only to the stripe type arrangement but also to the mosaic type or delta type arrangement.

  (Modification 5) In the functional liquid ejection method of the above-described embodiment, the configuration of the drive waveforms PL1, PL2, and PL3 for realizing time-division driving is not limited to this. For example, time-division driving is possible even with two types of waveform configurations.

  (Modification 6) The configuration of the ejection device 10 in the above embodiment is not limited to this. For example, the arrangement of the ejection heads 50 mounted on the head plate 9a may be changed depending on the type of functional liquid to be ejected.

  DESCRIPTION OF SYMBOLS 50 ... Discharge head, 52 ... Nozzle, 90R, 90G, 90B ... Functional liquid containing light emitting layer forming material, 100 ... Organic EL device, 101 ... Element substrate as a substrate, 112 ... Organic EL element, 132r, 132g, 132b ... Light emitting layer, 132R, 132G, 132B ... functional layer, 133 ... partition, A, A1, A2 ... functional layer forming region.

Claims (9)

A functional layer forming material is included from a nozzle group including at least two nozzles applied to the functional layer forming region during a plurality of scans in which a discharge head having a plurality of nozzles is moved relative to the functional layer forming region. A functional liquid ejection method for ejecting functional liquid as droplets,
A functional liquid ejection method, wherein at least one nozzle in the nozzle group is not selected, and the same number of nozzles is selected for each scan.   The functional liquid ejection method according to claim 1, wherein the same nozzle is selected from the nozzle group for each scanning.   The functional liquid ejection method according to claim 1, wherein a defective nozzle that does not properly eject the liquid droplets is used as the non-selected nozzle.   The functional liquid ejection method according to claim 1, wherein a nozzle selected from the nozzle group is changed during the plurality of scans.   The functional liquid ejection method according to claim 1, further comprising a partition wall surrounding the functional layer forming region, wherein a nozzle at the partition wall is selected from the nozzle group. A method for producing an organic EL element having a functional layer including a light emitting layer in a functional layer forming region on a substrate,
A step of discharging a functional liquid containing a functional layer forming material to the functional layer forming region using the functional liquid discharging method according to claim 1;
And a step of solidifying the discharged functional liquid to form at least one of the functional layers. A method for manufacturing an organic EL element, comprising:   The method for producing an organic EL element according to claim 6, wherein the functional liquid containing a light emitting layer forming material is discharged to the functional layer forming region to form the light emitting layer in the functional layer.   An organic EL device comprising the organic EL element manufactured using the method for manufacturing an organic EL element according to claim 6.   An electronic apparatus comprising the organic EL device according to claim 8.

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