JP2011048915A - Manufacturing device of luminescent panel, manufacturing method of the same and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing device of a luminescent panel and a manufacturing method of the same, capable of mass-producing the luminescent panels excellent in light emission characteristics with high manufacturing efficiency, and to provide an electronic apparatus having the luminescent panel which is suppressed in the variations of emission luminance. <P>SOLUTION: A nozzle coat film-deposition device 100, constituting the manufacturing device of luminescent panels, applies ink into a slit 21a in each column of an application mask 21, by scanning a nozzle head 111 in an X-direction with the application mask 21 adhered to a surface of a substrate 11 at the step of applying the ink onto the surface of the substrate 11. Then, the device heat-treats the substrate 11, which is in a state where an organic solution 14x is applied to and filled in the slits 21a, in all columns under reduced pressure, to uniformly and totally dry it to film-deposit an organic EL layer 14, on a pixel electrode 12 exposed to an EL element formation region Re1 of each pixel PIX. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting panel manufacturing apparatus, a manufacturing method therefor, and an electronic device, and more particularly, a light emitting panel in which a light emitting functional layer is formed by applying a liquid material by a nozzle printing method (or nozzle coating method). The present invention relates to an apparatus, a manufacturing method thereof, and an electronic device including a light-emitting panel manufactured by the manufacturing method.

  2. Description of the Related Art Recently, a display panel (light emitting element type display panel) in which light emitting elements such as organic electroluminescence elements (hereinafter abbreviated as “organic EL elements”) are two-dimensionally arranged as display devices for electronic devices such as mobile phones and portable music players. ) Is known. In particular, a light-emitting element type display panel to which an active matrix driving method is applied has a faster display response speed and less viewing angle dependency than a widely used liquid crystal display device. And the display image quality can be increased. In addition, the light emitting element type display panel does not require a backlight or a light guide plate unlike a liquid crystal display device, and thus has a feature that it can be further reduced in thickness and weight.

  As a light-emitting element applied to such a display panel, in recent years, development of an organic EL element using a polymer organic material for a light-emitting functional layer has been advanced. This polymer organic EL element generally has a structure in which an anode electrode (anode) and a cathode electrode (cathode) are formed so as to sandwich an organic EL layer (light emitting functional layer). Then, by applying a voltage to the anode electrode and the cathode electrode so as to exceed the light emission threshold value in the organic EL layer, light (excitation light) is generated based on energy generated when holes and electrons recombine in the organic EL layer. ) Is emitted.

  By the way, as a formation method of the light emitting functional layer in the polymer organic EL element, the light emitting functional layer is formed on the substrate by using, for example, an inkjet method (droplet discharge method) or a nozzle printing method (or nozzle coating method). A technique of applying an organic material for forming is known. In such a method for forming a light emitting functional layer, the formation region of each organic EL element arranged on the substrate is defined, and the application state of the organic material (that is, the film formation state of the light emitting functional layer) in each formation region is determined. In order to make it uniform, it is known to apply a substrate structure in which partition walls are provided between formation regions (boundary regions) on a substrate. An organic EL display panel having such a partition is described in, for example, Patent Documents 1 and 2. In these patent documents, there is disclosed a substrate structure provided with a partition wall that protrudes in a lattice shape on a substrate.

JP 2001-076881 A JP 2008-108737 A

  The method for forming a light emitting functional layer as disclosed in Patent Documents 1 and 2 described above has the following problems. That is, in the case of a substrate structure in which partition walls are provided in a lattice shape in the boundary region between each organic EL element arranged on the substrate, when the organic material is applied, the organic material is uniformly applied to the formation region of each organic EL element. In order to do so, an ink jet method is used. Here, the ink jet method has a feature that a uniform light emitting functional layer can be formed by applying a desired discharge amount of an organic material directly and accurately to the formation region of each organic EL element. .

  However, the inkjet method has a problem in that the organic material may be rebounded or scattered when it is deposited on the substrate surface because the organic material is directly applied to the formation region of each organic EL element. In addition, in the ink jet method, since the head of the ink nozzle needs to be aligned with high accuracy in the formation region of each organic EL element, for example, when applied to the manufacture of a high-definition display panel, the control is complicated and complicated. It also had the problem of becoming. Therefore, a technique capable of mass-producing display panels with high manufacturing efficiency is demanded.

  As a method for solving the above-described problems, a method of applying an organic material using a nozzle coating method (or nozzle printing method) instead of the ink jet method is also conceivable. However, in the case of a substrate structure in which a grid-like partition is provided on the substrate, a part of the liquid flow of the organic material discharged from the nozzle remains on the partition, so that the organic material is not uniformly applied to each formation region. In addition, the organic EL element has a problem in that the lifetime, the light emission characteristics are deteriorated, the light emission luminance is uneven, and the like. In addition, the problem at the time of using a nozzle coating method is demonstrated in detail in embodiment of invention mentioned later.

  Therefore, in view of the above-described problems, an object of the present invention is to provide a light emitting panel manufacturing apparatus and a manufacturing method thereof capable of mass-producing a light emitting panel having high manufacturing efficiency and excellent light emission characteristics. Another object of the present invention is to provide an electronic device including a light-emitting panel that is excellent in element lifetime and light emission characteristics and in which variation in light emission luminance is suppressed.

  According to a first aspect of the present invention, there is provided a plurality of pixels each including a light emitting element in which a first electrode, a light emitting functional layer including at least one layer, and a second electrode are stacked on a substrate, and at least two pixels are arranged in a specific column. In a light emitting panel manufacturing apparatus in which are arranged, a nozzle that discharges and applies ink to each pixel formation region set on the substrate, and at least two or more pixel formation regions in the specific row And a mask adhesion control section for detachably adhering a mask adhesion surface having an opening through which the mask is exposed.

According to a second aspect of the present invention, in the light emitting panel manufacturing apparatus according to the first aspect, the contact surface of the mask has liquid repellency.
According to a third aspect of the invention, there is provided the light emitting panel manufacturing apparatus according to the first or second aspect, further comprising an ink drying processing unit that heat-treats the substrate coated and filled with the ink in a reduced pressure state. It is characterized by.
According to a fourth aspect of the present invention, in the light emitting panel manufacturing apparatus according to any one of the first to third aspects, the mask corresponds to a formation region of all the pixels arranged on the substrate. A plurality of the openings are provided.
According to a fifth aspect of the present invention, in the light-emitting panel manufacturing apparatus according to any one of the first to third aspects, the mask is provided only in a formation region of the pixels in a specific column arranged on the substrate. Correspondingly, a plurality of the openings are provided.
A sixth aspect of the present invention is the light emitting panel manufacturing apparatus according to any one of the first to fifth aspects, wherein the mask is made of a magnetic material, and the mask adhesion control unit attracts the mask by a magnetic force. It is characterized by being closely attached to the substrate.

  According to a seventh aspect of the present invention, a plurality of pixels each including a light emitting element in which a first electrode, a light emitting functional layer including at least one layer, and a second electrode are stacked on a substrate, and each formation region of the plurality of pixels are defined. In the method for manufacturing a light-emitting panel, the plurality of pixel formation regions arranged in the column direction are exposed on the substrate, and a plurality of openings having lyophilic properties inside are provided. A step of closely attaching the contact surface of the mask on the partition, a step of discharging ink while scanning a nozzle along the opening, and applying and filling the ink in the opening; And drying the substrate on which the ink has been applied and filled to form a light emitting functional layer of the pixel.

  According to an eighth aspect of the present invention, in the method for manufacturing a light-emitting panel according to the seventh aspect, the mask is provided with the openings corresponding only to the formation regions of the pixels in a specific column arranged on the substrate. And removing the mask on the partition, applying the ink into the openings, filling the openings, and heating the substrate while moving the openings to different rows on the substrate and aligning the openings. The processing step is repeatedly performed.

  An electronic apparatus according to a ninth aspect of the invention is characterized in that a light emitting panel formed by applying the manufacturing method according to the seventh or eighth aspect is mounted.

  According to the manufacturing apparatus and the manufacturing method of a light emitting panel according to the present invention, a light emitting panel having high manufacturing efficiency and excellent light emission characteristics can be mass-produced. In addition, according to the electronic apparatus of the present invention, it is possible to realize an image display that is excellent in element lifetime and light emission characteristics and in which variation in light emission luminance is suppressed.

It is a schematic block diagram which shows the nozzle coat film-forming apparatus to which the manufacturing apparatus of the light emission panel which concerns on this invention is applied. It is a principal part block diagram which shows the substrate stage of the nozzle coat film-forming apparatus which concerns on 1st Embodiment. It is a schematic plan view which shows an example of the display panel manufactured with the nozzle coat film-forming apparatus which concerns on 1st Embodiment. It is a schematic sectional drawing which shows an example of the display panel manufactured with the nozzle coat film-forming apparatus which concerns on 1st Embodiment. It is process sectional drawing (the 1) which shows an example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is process sectional drawing (the 2) which shows an example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is process sectional drawing (the 3) which shows an example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is a top view (the 1) of a substrate and a substrate stage which shows a specific example of a manufacturing method of a display panel to which a nozzle coat film deposition system concerning a 1st embodiment is applied. It is the top view (the 2) of the board | substrate and substrate stage which shows the specific example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is process sectional drawing (the 1) which shows the principal part specific example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is process sectional drawing (the 2) which shows the principal part specific example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is process sectional drawing (the 3) which shows the principal part specific example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on 1st Embodiment is applied. It is a top view of the board | substrate and substrate stage which show an example of the manufacturing method of the display panel used as a comparison object. It is process sectional drawing which shows an example of the manufacturing method of the display panel used as a comparison object. It is the schematic of the board | substrate which shows the specific example of the manufacturing method (film formation process of an organic electroluminescent layer) of the display panel which concerns on 2nd Embodiment. It is process sectional drawing which shows an example of the manufacturing method of the display panel which concerns on 2nd Embodiment. It is a perspective view which shows the structure of the digital camera which concerns on 3rd Embodiment. It is a perspective view which shows the structure of the mobile type personal computer which concerns on 3rd Embodiment. It is a figure which shows the structure of the mobile telephone which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a manufacturing apparatus and a manufacturing method of a light emitting panel according to the present invention, and an electronic device including a light emitting panel formed by the manufacturing method will be described in detail with reference to embodiments.

<First Embodiment>
(Emission panel manufacturing equipment)
First, the manufacturing apparatus of the light emission panel which concerns on this invention is demonstrated with reference to drawings. Here, a case where the light emitting panel manufacturing apparatus according to the present invention is applied to a nozzle coat film forming apparatus and a display panel in which a plurality of pixels including organic EL elements are arranged is manufactured as the light emitting panel will be described.

  FIG. 1 is a schematic configuration diagram showing a nozzle coat film forming apparatus to which a light emitting panel manufacturing apparatus according to the present invention is applied. FIG. 1A is a schematic plan view of a substrate stage of a nozzle coat film forming apparatus as viewed from above, and FIG. 1B is a schematic block diagram showing the overall configuration of the nozzle coat film forming apparatus. Moreover, FIG. 2 is a principal part block diagram which shows the substrate stage of the nozzle coat film-forming apparatus which concerns on this embodiment. FIG. 2A is a schematic plan view of a substrate placed and fixed on the substrate stage of the nozzle coat film forming apparatus as seen from above, and FIG. 2B is an overhead view of the substrate stage from the side. FIG. In FIG. 2A, some components are hatched for clarity of illustration.

  The nozzle coat film forming apparatus (light emitting panel manufacturing apparatus) 100 according to the first embodiment is roughly divided into an ink ejection mechanism section and a substrate movable mechanism section. The ink ejecting mechanism scans a liquid flow of ink that becomes an organic EL layer (carrier transport layer, light emitting layer, etc .; light emitting functional layer) while scanning the nozzle head in a specific direction (X direction) with respect to the panel substrate (substrate). It has a function that keeps flowing continuously. That is, the nozzle coat film forming apparatus according to the present embodiment is different from the one that discharges a plurality of liquid droplets discontinuously on the panel substrate as in a known ink jet film forming apparatus. Further, the substrate moving mechanism moves the panel substrate in a direction perpendicular to the scanning direction of the nozzle head (a direction orthogonal to the substrate plane; Y direction), so that the nozzle head is relative to the panel substrate. Is provided with a function of controlling to move in the two-dimensional coordinate direction.

  Here, in the nozzle coat film forming apparatus according to the present embodiment, the hole transport material for forming the organic EL layer (hole transport layer; carrier transport layer) of the organic EL element is, for example, a conductive polymer. An organic solution in which polyethylenedioxythiophene PEDOT and a polystyrene sulfonate PSS (hereinafter abbreviated as “PEDOT / PSS”) as a dopant are dispersed in water and a high-boiling solvent is added (corresponding to the ink described above) Use). In the present embodiment, as an electron transporting light-emitting material for forming an organic EL layer (electron transport layer / light-emitting layer; carrier transport layer) of an organic EL element, for example, a polyphenylene vinylene polymer, a polyfluorene polymer, or the like An organic solution (corresponding to the ink described above) in which the conjugated polymer is added to a solvent having a high boiling point is used.

Hereinafter, each mechanism part of the nozzle coat film forming apparatus according to the present embodiment will be specifically described.
(Ink ejection mechanism)
For example, as shown in FIGS. 1A and 1B, the ink ejection mechanism unit includes a nozzle head (nozzle) 111, a pump unit 112, a flow rate control unit 113, an ink tank 114, and a head scanning unit 115. A discharge controller 116. Here, the flow rate control unit 113, the head scanning unit 115, and the ejection control unit 116 correspond to the ink application control unit according to the present invention.

  The nozzle head 111 discharges and applies the ink to the substrate (panel substrate) 11 placed and fixed on the substrate stage 121. Here, the nozzle head 111 is supported by the head scanning unit 115 and based on a control signal from a robot control unit 125 described later with respect to the substrate stage 121 in the X direction (main scanning direction; double arrow Xm in FIG. 1). Move to).

  As shown in FIG. 1B, the pump unit 112 sends out the ink stored in the ink tank 114 at a constant pressure based on the drive signal output from the flow rate control unit 113. The flow rate control unit 113 includes a flow meter and a valve, controls the valve based on the measured flow rate, and controls the flow rate as specified by the discharge control unit 116.

  The discharge controller 116 controls the amount of ink discharged from the nozzle head 111 (discharge amount). Specifically, the ejection control unit 116 analyzes the amount of ink ejected onto the substrate 11 by the nozzle head 111 based on the result of analyzing image information data related to the mounting position of the substrate 11 by the image processing unit 124 described later. A control signal for controlling (discharge amount) is output, and discharge amount data is output to the flow rate control unit 113.

  As a result, the flow rate control unit 113 adjusts the flow rate based on the discharge amount calculated by the discharge control unit 116, whereby a predetermined amount of ink is discharged from the discharge port of the nozzle head 111 toward the substrate 11 on the substrate stage 121. The

  As shown in FIG. 1B, the nozzle head 111 moves in the X direction (main scanning direction) and in addition to the mounting surface (substrate plane) of the substrate stage 121 (Z direction; FIG. It may be controlled so as to be movable up and down at an arbitrary position indicated by a double arrow Zm. Thereby, the clearance (separation distance) between the nozzle head 111 and the board | substrate 11 (or board | substrate stage 121) can be adjusted arbitrarily.

(Substrate moving mechanism)
For example, as shown in FIGS. 1A and 1B, the substrate moving mechanism unit includes a substrate stage 121, a uniaxial robot 122, an alignment camera 123, an image processing unit 124, and robot control. Part 125. Here, the image processing unit 124 and the robot control unit 125 correspond to an ink application control unit according to the present invention.

  The substrate 11 is placed and fixed on the upper surface of the substrate stage 121. Further, as shown in FIG. 1A, the substrate stage 121 is moved in the Y direction (X direction orthogonal to the scanning direction (X direction; arrow Xm) of the nozzle head 111 by the head scanning unit 115 described above by the uniaxial robot 122. It is controlled so as to be movable to an arbitrary position in the sub-scanning direction (indicated by a double arrow Ym in the figure).

  The alignment camera 123 detects the placement position of the substrate 11 on the substrate stage 121 with respect to the nozzle head 111 in a state where the nozzle head 111 and the substrate stage 121 are set to predetermined reference positions. The image processing unit 124 analyzes an image captured by the alignment camera 123. Then, the robot control unit 25 drives and controls the single-axis robot 122 based on the analysis result in the image processing unit 124 to adjust the relative positional relationship between the nozzle head 111 and the substrate stage 121.

  Specifically, the robot control unit 125 is mounted on the upper surface of the substrate stage 121, and the substrate stage 121 is connected to the nozzle head corresponding to the pitch (interval) of pixels (organic EL elements) arranged on the fixed substrate 11. The single-axis robot 122 is driven and controlled so as to move in the Y direction at a predetermined pitch with respect to 111. Here, as described above, the nozzle head 111 is scanned in the X direction with respect to the substrate stage 121 by the head scanning unit 115 based on the control signal from the robot control unit 125. 11 relative to the X-Y2 axis direction (two-dimensional coordinate direction). As a result, the liquid-state ink ejected from the nozzle head 111 is applied to all the pixels arranged in the pixel array region of the substrate 11.

  Although not shown, the substrate stage 121 includes a vacuum suction mechanism and a mechanical fixing mechanism for fixing the substrate 11 placed on the upper surface thereof to a predetermined position. In addition to the movement in the Y direction by the single-axis robot 122 for the alignment (positioning) of the initial ejection position of the nozzle head 111 with respect to the substrate 11, the substrate stage 121, as shown in FIG. The structure is such that fine adjustment movement is possible even in the rotation direction (θ direction) in which the placement surface is rotated within the substrate plane with the center of gravity of the placement surface of the substrate stage 121 as an axis. The nozzle coat film forming apparatus 100 replaces such a moving structure that rotates the substrate stage 121 with a head scanning unit 115 that supports the nozzle head 111 in a plane parallel to the substrate stage 121 (substrate plane). The initial ejection position of the nozzle head 111 may be adjusted by rotating the nozzle head 111.

  Furthermore, as shown in FIGS. 1 and 2, the substrate stage 121 according to the present embodiment is provided with a mechanism for bringing the coating mask 21 into close contact with the substrate 11 placed and fixed on the upper surface thereof. ing. Here, as will be described in detail later, the coating mask 21 has a plurality of pixels (organic) arranged in the X direction on the substrate 11 (that is, the scanning direction of the nozzle head 111), as shown in FIG. (EL element) A plurality of stripe-shaped openings (hereinafter referred to as “slits”) 21 a are formed so as to expose the formation region of PIX.

  Specifically, the adhesion mechanism of the coating mask 21 applied to the present embodiment is, for example, when a magnetic material is used as the coating mask 21, as shown in FIG. An electromagnet 126 for attracting the coating mask 21 with a magnetic force to closely contact the surface of the substrate 11 at the lower part or inside, and an electromagnet drive control unit 127 for driving and controlling the electromagnet 126 are provided. Here, when the coating mask 21 has a size corresponding to, for example, the pixel array region of the substrate 11, the electromagnet 126 has a function of only bringing the coating mask 21 into close contact with the entire pixel array region. Has a surface. The electromagnet 126 and the electromagnet drive controller 127 correspond to the mask contact controller according to the present invention.

  In the nozzle coating film forming apparatus according to the present embodiment, in the step of applying ink to the surface of the substrate 11, the nozzle drive head 21 is brought into close contact with the surface of the substrate 11 by the electromagnet drive control unit 127. 111 is scanned in the X direction to apply ink into the slit 21 a of the coating mask 21. On the other hand, after completion of the ink application process (strictly, after the ink is dried under reduced pressure; details will be described later), the electromagnet drive control unit 127 removes the application mask 21 closely attached to the surface of the substrate 11 (detachment). ) Thus, the adhesion mechanism of the coating mask 21 is configured so that the coating mask 21 can be attached to and detached from the surface of the substrate 11. The contact mechanism of the application mask 21 is replaced with a mechanism that attaches the application mask 21 to the surface of the substrate 11 using magnetic force as shown in FIG. It may be provided with a fixing (clamping) mechanism that presses and closely contacts. In this case, the coating mask 21 may be made of a material other than the magnetic material as long as it is a flat and strong thin film and can accurately pattern the slit 21a.

(Display panel)
Next, a display panel (light emitting panel) manufactured by the nozzle coat film forming apparatus according to this embodiment will be described.

  FIG. 3 is a schematic plan view showing an example of a display panel manufactured by the nozzle coat film forming apparatus according to the present embodiment. FIG. 4 is a schematic cross-sectional view showing an example of a display panel manufactured by the nozzle coat film forming apparatus according to the present embodiment. Here, FIG. 4A shows the IVA-IVA line (in this specification, “IV” as a symbol corresponding to the Roman numeral “4” shown in FIG. 3 for convenience). 4B is a schematic cross-sectional view showing a cross section taken along line IVB-IVB of the display panel in FIG. 3, and FIG. FIG. 4 is a schematic cross-sectional view showing a cross section taken along line IVC-IVC of the display panel in FIG. 3. In the plan view shown in FIG. 3, for convenience of explanation, the pixel electrode provided in each pixel and each pixel when viewed from one surface side (the organic EL element formation surface side) of the display panel (substrate). Only the arrangement relationship with the partition walls (banks) defining the formation region (EL element formation region) is shown, and hatching is shown for convenience in order to clarify the arrangement of the partition walls.

  As shown in FIG. 3, a display panel (light emitting panel) 10 manufactured by the nozzle coat film forming apparatus according to this embodiment includes a light emitting element in a pixel array region Rpx on one surface side of an insulating substrate 11 such as glass. A plurality of pixels PIX each having the organic EL element OEL are arranged in the row direction (the horizontal direction in the drawing; corresponding to the Y direction in the nozzle coat film forming apparatus described above) and the column direction (the vertical direction in the drawing; the nozzle coat film forming described above). Corresponding to the X direction in the apparatus).

  Further, as shown in FIGS. 3 and 4A to 4C, the display panel 10 protrudes from one surface side of the substrate 11 and has a partition wall (bank) 13 formed with a lattice-shaped opening 13 a. Thus, a formation region (hereinafter, referred to as “EL element formation region”) Rel of the organic EL element OEL of each pixel PIX that is two-dimensionally arranged on one surface side of the substrate 11 is defined. Here, in addition to the role of defining the EL element formation region Rel as an individual region, the partition wall 13 having a lattice-like planar pattern drives the organic EL element OEL to emit light in the boundary region where the partition wall 13 is formed. In addition, a circuit element (such as a thin film transistor) and a wiring layer are arranged to ensure the aperture ratio of the display panel 10. In addition, the partition 13 arrange | positions the 1st partition for arrange | positioning the circuit element and wiring layer for light emission driving of the organic EL element OEL, and ensuring the aperture ratio of the display panel 10, and EL element formation area Rel separately. It may consist of a two-layer structure with a second partition wall for defining as a region.

  In the EL element formation region Rel of each pixel PIX, as shown in FIGS. 4A and 4B, a pixel electrode (for example, an anode electrode) 12 and an organic EL layer 14 (for example, a hole transport layer 14a and a hole transport layer 14a) An electron transporting light emitting layer 14b) and a counter electrode (for example, a cathode electrode) 15 are provided to form each organic EL element OEL. Here, the organic EL layer 14 (the hole transport layer 14 a and the electron transport light emitting layer 14 b) is formed by applying a predetermined ink on each pixel electrode 12 by the nozzle coat film forming apparatus 100 described above. The counter electrode 15 is formed of a single electrode layer (solid electrode) so as to face each pixel electrode 12 in common via the organic EL layer 14 of each pixel PIX. 4A to 4C, reference numeral 16 denotes a protective insulating film or a sealing resin layer.

  The display panel 10 may further include a sealing substrate (not shown) provided on the protective insulating film (or sealing resin layer) 16. Further, in the present embodiment, the element structure in which the pixel electrode 12 of the organic EL element OEL is directly formed on the substrate 11 is shown, but the present invention is not limited to this. That is, the display panel (light-emitting panel) 10 according to the present invention may have an element structure in which the pixel electrode 12 is formed on the substrate 11 via the insulating film.

  The display panel (light-emitting panel) 10 may be an active matrix drive type or a simple matrix (passive matrix) drive type. When the display panel 10 is of the active matrix drive type, for example, circuit elements (thin film transistors, capacitors, etc.) and wiring layers for driving the organic EL elements OEL to emit light are formed on the substrate 11 and the interlayer insulation covering these elements is formed. It may have an element structure in which the pixel electrode 12 is formed on a film or a planarizing film.

  Furthermore, the organic EL element OEL provided in the display panel 10 may have a bottom emission type light emitting structure, or may have a top emission type light emitting structure. When the organic EL element OEL has a bottom emission type light emitting structure, the light emitted from the organic EL layer 14 is emitted to the other surface side of the substrate 11 (downward in FIG. 4) through the pixel electrode 12 and the substrate 11. The Further, when the organic EL element OEL has a top emission type light emitting structure, light emitted from the organic EL layer 14 is transmitted to the one surface of the substrate 11 through the counter electrode 15 and the protective insulating film (or sealing resin layer) 16. The light is emitted to the side (upper side in FIG. 4).

(Display panel manufacturing method)
Next, a method for manufacturing a display panel (light emitting panel) to which the nozzle coat film forming apparatus as described above is applied will be described. Here, a case where the organic EL element OEL formed in the display panel 10 has a bottom emission type light emitting structure will be described.

  5-7 is process sectional drawing which shows an example of the manufacturing method of the display panel to which the nozzle coat film-forming apparatus which concerns on this embodiment is applied. Here, FIG. 5 is a process sectional view in a section taken along the line IVA-IVA of the display panel 10 shown in FIG. FIG. 6 is a process cross-sectional view taken along a line IVB-IVB of the display panel 10 shown in FIG. FIG. 7 is a process cross-sectional view taken along the line IVC-IVC of the display panel 10 shown in FIG.

  8 and 9 are plan views of a substrate and a substrate stage showing a specific example of a display panel manufacturing method (organic EL layer forming step) to which the nozzle coat film forming apparatus according to this embodiment is applied. For convenience, FIG. 8 shows a case where the organic solution is applied only to a region corresponding to a pixel in a specific column. In addition, in the plan views shown in FIGS. 8 and 9, hatching is shown for convenience in order to clarify the arrangement relationship between the partition walls and the coating mask and the coating state of the organic solution.

  10 to 12 are process cross-sectional views illustrating specific examples of main parts of a display panel manufacturing method (organic EL layer film forming process) to which the nozzle coat film forming apparatus according to this embodiment is applied. Here, FIG. 10 is an XD-XD line of the substrate 11 shown in FIG. 8A (in this specification, as a symbol corresponding to the Roman numeral “10” shown in FIG. 8A) for convenience. It is process sectional drawing in the cross section along (X is used). FIG. 11 is a cross-sectional view taken along the line XIE-XIE of the substrate 11 shown in FIG. 8A (in this specification, “XI” is used as a symbol corresponding to the Roman numeral “11” for convenience). It is sectional drawing. FIG. 12 is a cross-sectional view taken along the line XIIF-XIIF of the substrate 11 shown in FIG. 8A (in this specification, “XII” is used for convenience as the symbol corresponding to the Roman numeral “12”). It is sectional drawing.

  The manufacturing method of the display panel (light emitting panel) 10 according to the present embodiment is as follows. First, as shown in FIGS. 5A, 6A, and 7A, an insulating substrate made of a glass substrate or the like. A pixel electrode (for example, an anode electrode) 12 is formed on one surface side (upper surface side in FIG. 11) 11 of the organic EL element OEL formation region (EL element formation region) Rel of each pixel PIX. Here, the pixel electrode 12 is formed using a transparent electrode material such as tin-doped indium oxide (ITO) or zinc-doped indium oxide. Next, a partition wall (bank) 13 is formed in a boundary region with adjacent pixels PIX (EL element formation region Rel). Here, the partition wall 13 is formed using, for example, a photosensitive resin material. The partition wall 13 has a cross-sectional shape that continuously protrudes from the surface of the substrate 11 as shown in FIGS. 5 (a), 6 (a), and 7 (a). Further, as shown in FIG. 3, the partition wall 13 has a planar shape including a grid-like opening 13 a so that the upper surface of the pixel electrode 12 of each pixel PIX is exposed. In addition, the partition 13 arrange | positions the 1st partition for arrange | positioning the circuit element and wiring layer for light emission driving of the organic EL element OEL, and ensuring the aperture ratio of the display panel 10, and EL element formation area Rel separately. It may be a two-layer structure with a second partition for defining as a region. In this case, first, a first partition is formed so as to cover the circuit element and the wiring layer. The first partition is formed by depositing silicon nitride or the like by plasma CVD. A plurality of openings 13a are formed so that the upper surface of the pixel electrode 12 is exposed by patterning the first partition by photolithography. Next, a photosensitive resin such as polyimide is deposited and then exposed to form a second partition for defining the EL element formation region Rel as an individual region.

  Next, the substrate 11 on which the pixel electrode 12 and the partition wall 13 are formed is washed with pure water or alcohol, and then subjected to, for example, oxygen plasma treatment or UV ozone treatment to expose the pixel electrode exposed to each EL element formation region Rel. 12 surfaces are lyophilic. Thereby, the surface of the pixel electrode 12 is at least a parent to the organic solution (ink) 14x applied when forming the organic EL layer 14 (for example, the hole transport layer 14a and the electron transporting light emitting layer 14b) described later. Liquefaction.

Next, the substrate 11 is subjected to plasma treatment with a fluorinated gas such as carbon tetrafluoride CF ₄ , so that the surface of the partition wall 13 exhibits water repellency and oil repellency and repels the applied organic solution 14 x. . When the partition wall 13 has a two-layer structure having a first partition wall and a second partition wall, only the upper second partition wall may be liquid repellent. Here, when the partition wall 13 is formed of photosensitive polyimide, by performing plasma treatment with carbon tetrafluoride CF ₄ , the contact angle of the polyimide surface is about 100 ° in the case of water used as the solvent of the organic solution, xylene Shows a value of about 50 °. Here, in the lyophobic treatment using the plasma treatment with the fluorinated gas, the pixel electrode 12 made of a metal oxide such as ITO exposed in the EL element formation region Rel is exposed because it does not react with the oxide film or the nitride film. The surface of is not liquid repellent. Therefore, the surface of the pixel electrode 12 retains the lyophilic property imparted by the above-described lyophilic treatment (oxygen plasma treatment or UV ozone treatment).

  The “liquid repellency” used in the present embodiment refers to an organic solution 14x containing a hole transport material to be a hole transport layer 14a described later and an electron transport light-emitting material to be an electron transport light-emitting layer 14b. It is defined that the contact angle is 50 ° or more when the contact angle is measured by dropping the organic solution containing or the organic solvent used in these solutions onto the substrate 11 or the like. Further, “lyophilic” with respect to “liquid repellency” is defined as a state in which the contact angle is 40 ° or less in the present embodiment.

  Next, by applying the nozzle coat film forming apparatus 100 described above, an organic solution is applied to the EL element formation regions Rel of the plurality of pixels PIX arranged on the substrate 11, and the organic EL layer 14 (hole transport layer 14a) is applied. And an electron transporting light emitting layer 14b). First, prior to the application of the organic solution to the substrate 11, as shown in FIGS. 6 (b), 7 (b), and 8 (a), a process of bringing the coating mask 21 into close contact with the surface of the substrate 11 is executed. Is done. Specifically, as shown in FIG. 2, a coating mask 21 made of a magnetic material is placed on the surface of the substrate 11 while the substrate 11 is placed and fixed on the substrate stage 121 of the nozzle coat film forming apparatus 100. Placed. Then, by driving an electromagnet 126 provided below the substrate stage 121, the coating mask 21 is attracted toward the substrate stage 121 by a magnetic force and closely contacts the surface of the substrate 11.

  Here, the coating mask 21 has a shape and a size corresponding to the pixel array region Rpx of the display panel 10 shown in FIG. Further, the coating mask 21 is arranged in the X direction of the substrate stage 121 shown in FIG. 2A (left and right direction in FIG. 2A; arrow Xm), that is, in the column direction of the substrate 11 shown in FIG. A plurality of slits 21a are provided through which a plurality of pixels PIX (EL element formation region Rel) arranged in the vertical direction of FIG. 8A (arrow Xm) are exposed. Further, it is desirable that the coating mask 21 be formed of a material that can be satisfactorily attached to and detached from (attached to or detached from) the partition wall 13 provided on the substrate 11 placed and fixed on the substrate stage 121. For this reason, as described above, when the coating mask 21 is brought into close contact with the substrate 11 by using the magnetic force of the electromagnet 126 provided on the substrate stage 121, the coating mask 21 is, for example, invar ( A thin film of magnetic metal such as invariant steel can be applied satisfactorily. In this case, the film thickness of the coating mask 21 is determined by the material of the coating mask 21, the amount of the organic solution applied in the slit 21 a, the degree of lyophilicity and liquid repellency with respect to the organic solution, and the close contact with the partition wall 13. However, when the magnetic metal thin film such as Invar is applied, it is set to about 50 μm, for example.

  The coating mask 21 is aligned so that the pixel electrodes 12 of each pixel PIX (EL element formation region Rel) arranged at least in the X direction (or column direction) are exposed in each slit 21a. The substrate 11 is in close contact with the surface. That is, as shown in FIGS. 6B, 7B, and 8A, the coating mask 21 is formed in the Y direction of the substrate stage 121 shown in FIG. 2A (see FIG. 2A). (Particularly in the vertical direction), that is, the partition wall 13 formed in the boundary region between the pixels PIX (EL element formation region Rel) adjacent to each other in the row direction of the substrate 11 shown in FIG. 8A (left-right direction in FIG. 8A). The connection part 21b between the slits 21a is in close contact with the top. As a result, each slit 21a of the coating mask 21 surrounds the pixel electrode 12 of each pixel PIX arranged in the X direction (or the column direction) and the pixel electrode 12 as shown in FIG. 8A. A part of the partition wall 13 is exposed.

  Here, the coating mask 21 is in close contact with the partition wall 13 so that the organic solution 14x does not permeate and enter the contact surface 21c between the coating mask 21 and the partition wall 13 in the application step of the organic solution 14x described later. It is desirable that the surface 21c has liquid repellency. In addition, the coating mask 21 is lyophilic so that the organic solution 14x applied and filled in each slit 21a is appropriately drawn by contacting the side wall of the slit 21a in the coating step of the organic solution 14x described later. It is desirable to have the property. The liquid repellent treatment of the adhesion surface 21c of the coating mask 21 is performed, for example, by immersing a metal mask in a fluorine-based surface treatment agent to form a 5 to 10 nm liquid repellent layer. As an example of the fluorine-based surface treatment agent, there is EGC-1720 manufactured by 3M. The liquid repellent layer preferably has a long-lasting effect. The lyophilic treatment on the side surface of the slit 21a is performed, for example, by performing the UV ozone treatment in the state where the metal mask is in close contact with the electromagnet after the above-described lyophobic treatment. This makes it possible to make the side surface of the slit lyophilic without impairing the liquid repellency of the surface in close contact with the electromagnet. When the lyophilicity is deteriorated, the lyophilic property can be obtained by using the above method again.

  Next, as shown in FIGS. 5C, 6C, 7C, and 8A, while the nozzle head 111 is scanned in the X direction (column direction) of the substrate stage 121, the substrate An organic solution (ink) 14x formed by adding a hole transport material (for example, PEDOT / PSS described above) to a solvent having a high boiling point (for example, a boiling point of 200 ° C. or higher) is applied to the substrate 11 placed on the stage 121. To do. That is, the organic solution 14x is not a quick-drying one that is dried immediately after application, and the organic solution 14x applied to the substrate 11 can be uniformly and collectively dried in a drying step (decompression, heat treatment) described later. Use what you can. Further, the discharge amount of the organic solution 14x discharged from the nozzle head 111 in a liquid flow is set by the discharge control unit 116 described above. As a result, as shown in FIG. 8B, the nozzle head 111 continues from the slit 21a of the coating mask 21 in which the EL element formation regions Rel of the plurality of pixels PIX arranged in the column direction of the substrate 11 are exposed. The organic solution 14x that has been discharged is applied and filled.

  Then, the process of applying the organic solution 14x in the slits 21a in which the pixels PIX (EL element formation regions Rel) in such a specific column are exposed is performed on all the slits 21a of the coating mask 21 that is in close contact with the substrate 11. Repeat about. Specifically, after applying the organic solution 14x while scanning the nozzle head 111 in the row direction (X direction) along the slits 21a in a specific row, the nozzle head 111 is placed at the position of the slit 21a in the adjacent row. The substrate stage 121 is pitch-moved in the row direction (Y direction) by the single-axis robot 122 so as to move. An operation of applying the organic solution 14x by moving the nozzle head 111 in such a column direction, and a pitch movement of the substrate stage 121 in the row direction (Y direction) to move the nozzle head 111 to the position of the slit 21a in the adjacent column. The organic solution 14x is applied and filled in the slits 21a of all rows by repeatedly performing the movement operation alternately. As a result, the organic solution 14x is applied to the EL element formation regions Rel of all the pixels PIX arranged in the display panel 10.

  Next, the substrate 11 in which the organic solution 14x is applied and filled in the slits 21a of all the rows is subjected to heat treatment in a state where the pressure is reduced in a drying processing chamber (ink drying processing unit) (not shown), and the organic solution 14x. The solvent is vaporized and uniformly and collectively dried, as shown in FIG. 5D, FIG. 6D, and FIG. 9, on the pixel electrode 12 exposed in the EL element formation region Rel of each pixel PIX. Then, the hole transport layer 14a is formed.

  Next, in the same manner as the film forming step of the hole transport layer 14a described above, the organic polymer-based electron transporting light-emitting material (for example, the above-described process) is performed while moving the nozzle head 111 and the substrate stage 121 in the X and Y directions, respectively. An organic solution (ink) obtained by adding polyphenylene vinylene polymer) to a solvent having a high boiling point (for example, a boiling point of 200 ° C. or higher) is applied and filled in each slit 21 a of the coating mask 21. Then, with the organic solution 14x applied and filled in the slits 21a of all rows, the substrate 11 is subjected to reduced pressure and heat treatment, and the organic solution 14x is uniformly and collectively dried, whereby FIG. e) As shown in FIG. 6E, the electron-transporting light-emitting layer 14b is formed on the hole-transport layer 14a formed in the EL element formation region Rel of each pixel PIX. Thereby, the organic EL layer 14 including the hole transport layer 14a and the electron transporting light emitting layer 14b is formed on the pixel electrode 12 of each pixel PIX.

  Here, the method for forming the organic EL layer 14 according to the present embodiment (that is, a series of processing steps in which the organic EL layer 14 is formed by applying the organic solution 14x and then drying by heating), and the substrate 11 The relationship with the coating mask 21 that is in close contact with the upper side will be described in more detail.

  In the film-forming process of the organic EL layer 14 using the nozzle coat film-forming apparatus 100 according to the present embodiment, as shown in FIG. 8A, the slit 21a of the coating mask 21 in close contact with the substrate 11 is provided. The organic solution 14x is continuously ejected while scanning the nozzle head 111 in the column direction (X direction). As a result, as shown in FIG. 8B, the organic solution 14x is filled (retained) in the slit 21a, and the EL element formation region Rel of each pixel PIX exposed in the slit 21a and its surroundings are exposed. An organic solution 14 x is applied on the partition wall 13.

  Here, as described above, the surface of the pixel electrode 12 exposed in the EL element formation region Rel of each pixel PIX is lyophilic, whereas the surface of the partition wall 13 is lyophobic. Further, the side wall of the slit 21a of the coating mask 21 that is in close contact with the partition wall 13 is lyophilic. Therefore, the organic solution 14x discharged from the nozzle head 111 along the slit 21a spreads out on the pixel electrode 12 having lyophilic properties. On the other hand, a repelling behavior is exhibited at a portion in contact with the liquid-repellent partition wall 13, and a pulling behavior is exhibited at the side wall of the slit 21 a of the coating mask 21. As a result, the organic solution immediately after coating is applied to the side wall (or connection) of the slit 21a of the coating mask 21 in close contact with the partition wall 13, as shown in FIGS. 10 (a), 11 (a), and 12 (a). The portion 21b) serves as a guide and stays well throughout the slit 21a without leaking into adjacent rows.

  And after application | coating of the organic solution 14x, as time passes, as shown in FIG.10 (b), FIG.11 (b), FIG.12 (b), the organic solution 14x which stayed on the partition 13 is shown. It moves in the column direction while being drawn along the side wall (connecting portion 21b) of the slit 21a, and flows into the adjacent EL element formation regions Rel via the partition walls 13. Thereby, the behavior of the organic solution 14x staying on the partition wall 13 is stabilized, and the organic solution 14x flows into the adjacent EL element formation region Rel through the partition wall 13 almost uniformly, so that the EL element of each pixel PIX The amount of the organic solution 14x staying in the formation region Rel becomes substantially uniform.

  In such a state, when the substrate 11 is subjected to reduced pressure and heat treatment to dry the organic solution 14x, the organic solution 14x is reduced in volume due to the evaporation of the solvent, and the volume of the organic solution 14x is reduced on the partition wall 13 in the slit 21a. As shown in FIGS. 10C to 10E, FIG. 11C, and FIG. 12C, the organic solution 14x stays only in each EL element formation region Rel. When the organic solution 14x is further dried, as shown in FIG. 9, FIG. 10 (f), FIG. 11 (d), and FIG. 12 (d), only in each EL element formation region Rel surrounded by the partition wall 13. Then, the hole transport material or the electron transporting light emitting material is fixed in a thin film, and the hole transporting layer 14a or the electron transporting light emitting layer 14b having a uniform film quality and film thickness is formed on the pixel electrode 12.

  Next, after removing the coating mask 21 in close contact with the partition wall 13 of the substrate 11, as shown in FIG. 5 (f), FIG. 6 (f), and FIG. A counter electrode (for example, a cathode electrode) 15 made of an electrode layer (solid electrode) is formed. Here, the counter electrode 15 has a shape and a size corresponding to at least the pixel array region Rpx of the display panel 10, and the organic EL layer 14 including the hole transport layer 14a and the electron transport light emitting layer 14b described above is interposed therebetween. Thus, the pixel electrodes 12 of the respective pixels PIX are formed so as to face each other in common. Thereafter, as shown in FIGS. 4A to 4C, a protective insulating film (or sealing resin layer) 16 is formed on the substrate 11 including the counter electrode 15. Thereby, as shown in FIGS. 3 and 4, the display panel 10 in which the pixels PIX including the organic EL elements OEL are two-dimensionally arranged on the substrate 11 is completed.

  Thus, in the film forming process of the organic EL layer 14 according to the present embodiment, the organic solution (ink) 14x applied using the nozzle coat film forming apparatus 100 described above is applied to the substrate 11 in close contact. It stays in the slit 21a of the mask 21. At this time, the organic solution 14x staying on the partition wall 13 provided between the adjacent pixels PIX in the slit 21a moves along the connecting portion 21b provided between the slits 21a. Since it flows almost uniformly into the element formation region Rel, the amount of the organic solution 14x staying in each EL element formation region Rel becomes substantially uniform.

  Therefore, according to the present embodiment, an organic EL layer (for example, hole transport) having a substantially uniform film quality and film thickness on the pixel electrode of each pixel with high manufacturing efficiency using the nozzle coating method (or nozzle printing method). Layer and electron-transporting light-emitting layer) can be formed. In an organic EL element (light emitting element) having such an organic EL layer, it is possible to suppress variations in light emission luminance and aperture ratio and deterioration in element lifetime due to variations in film quality and film thickness of the organic EL layer. Therefore, it is possible to mass-produce a display panel (light emitting panel) that has excellent light emission characteristics and good display quality.

(Verification of effects)
Next, the effect of using the organic EL layer deposition method using the nozzle coat deposition apparatus as described above will be described in more detail. Here, first, a method for forming an organic EL layer that does not use the coating mask shown in this embodiment as a comparison target will be described, and thereafter, the advantages of the effects in this embodiment will be described.

  FIG. 13 is a plan view of a substrate and a substrate stage showing an example of a method for manufacturing a display panel to be compared (film formation step of an organic EL layer). In the plan view shown in FIG. 13, hatching is shown for convenience in order to clarify the arrangement of the partition walls and the application state of the organic solution. FIG. 14 is a process cross-sectional view illustrating an example of a display panel manufacturing method (organic EL layer forming process) to be compared. Here, FIG. 14 is a process in a cross section along the line XIVG-XIVG of the substrate 11 shown in FIG. 13 (in this specification, “XIV” is used as a symbol corresponding to the Roman numeral “14” for convenience). It is sectional drawing. In FIG. 13 and FIG. 14, components equivalent to those in the above-described embodiment are shown with the same or equivalent symbols.

  Here, as mentioned in the problem to be solved by the present invention described above, a coating mask as shown in this embodiment is not used for a substrate provided with a partition having a lattice-like planar pattern. A method of forming an organic EL layer by directly applying an organic solution by a nozzle coating method is a comparison target.

  Specifically, the method for forming the organic EL layer to be compared has a lattice-like opening in the boundary region of the two-dimensionally arranged pixels PIX, as shown in FIGS. 13 and 14A. With the substrate provided with the partition walls placed and fixed on the substrate stage 121, the nozzle head 111 is moved in the column direction (X direction; X direction of FIG. 13) along the EL element formation region Rel of the pixel PIX in a specific column. The organic solution 14x is discharged while scanning in the vertical direction (arrow Xm). As a result, the organic solution 14x is applied to each EL element formation region Rel in the column and the partition 13 around it.

  Here, as in the case of the display panel manufacturing method described above, the surface of the pixel electrode 12 exposed in the EL element formation region Rel of each pixel PIX is lyophilic, while the surface of the partition wall 13 is It has liquid repellency. For this reason, the organic solution 14x discharged from the nozzle head 111 is familiar and spreads on each pixel electrode 12 having lyophilic properties, while being repelled at a portion in contact with the partition wall 13 having liquid repellency (water repellency, oil repellency). Shows behavior.

  In particular, as an organic solution for forming a hole injection layer, a strongly acidic aqueous ink in which PEDOT / PSS, which is a hole transporting material, is dissolved or dispersed in an aqueous solvent such as water, ethanol, ethylene glycol, or the like is used. As an organic solution for forming an electron-transporting light-emitting layer, a conjugated polymer such as a polyphenylene vinylene-based polymer or a polyfluorene-based polymer, which is an electron-transporting light-emitting material, is mixed with water, tetralin, tetramethylbenzene, mesitylene, When water-based ink or organic solvent-based ink dissolved or dispersed in an aromatic organic solvent such as xylene or toluene is used, the organic solution is repelled very well on the surface of the partition wall 13 having liquid repellency. Thereby, the organic solution 14x staying on the partition wall 13 flows from the partition wall 13 toward the adjacent EL element formation regions Rel as shown in FIGS. 14 (b) and 14 (c). At this time, the non-uniform flow from the partition wall 13 to the adjacent EL element formation region Rel causes variations in the amount of the organic solution 14x remaining in the EL element formation region Rel of each pixel PIX. If the liquid repellency of the partition wall 13 surface is not sufficient, the organic solution 14x applied on the partition wall 13 stays (residues) as it is, and flows into the EL element formation region Rel and stays there. The amount of the solution 14x may change.

  In such a state, when the substrate 11 is heat-treated and the organic solution 14x is dried, the solvent is vaporized, and in each EL element formation region Rel surrounded by the partition wall 13, FIG. As shown, the hole transport material or the electron transporting light emitting material is fixed on each pixel electrode 12 in a thin film shape. At this time, since the amount of the organic solution 14x staying in each EL element formation region Rel varies as described above, the film quality and film thickness of the hole transport layer 14a or the electron transport light emitting layer 14b to be formed are varied. Has the problem of non-uniformity.

  On the other hand, in the organic EL layer film forming method according to the present embodiment, the organic solution 14x applied on the substrate 11 stays in the slit 21a of the coating mask 21, so that the organic solution 14x is Along the connecting portion 21b provided between the slits 21a, the light flows into the EL element forming region Rel of the adjacent pixel PIX substantially evenly. At this time, in the present embodiment, the phenomenon that the applied organic solution 14x stays (residual) as it is on the partition wall 13 provided in the boundary region between the adjacent pixels PIX was not observed.

  Therefore, according to the present embodiment, the amount of the organic solution 14x staying in each EL element formation region Rel can be made substantially uniform, so that a substantially uniform film quality and film thickness are formed on the pixel electrode 12 of each pixel PIX. The organic EL layer 14 (for example, a hole transport layer and an electron transporting light emitting layer) can be formed. And according to the display panel (light emitting panel) in which organic EL elements (light emitting elements) having such an organic EL layer are arranged, it is possible to suppress variations in light emission luminance and aperture ratio, and deterioration in element life, which is favorable. Display quality can be achieved.

<Second Embodiment>
Next, a second embodiment of the method for manufacturing a light emitting panel according to the present invention will be described.
FIG. 15 is a schematic view of a substrate showing a specific example of a display panel manufacturing method (organic EL layer forming step) according to the second embodiment. Here, FIG. 15A is a schematic plan view showing the positional relationship between the substrate 11 having the partition wall 13 and the coating mask 21. FIG. 15B is along the XVH-XVH line of the substrate 11 shown in FIG. 15A (in this specification, “XV” is used as a symbol corresponding to the Roman numeral “15” for convenience). It is a schematic sectional drawing which shows the cross section. For convenience, FIG. 15 shows a case where the organic solution is applied only to a region corresponding to a pixel in a specific column. Further, in the plan view shown in FIG. 15A, hatching is shown for convenience in order to clarify the arrangement relationship between the partition walls and the coating mask and the coating state of the organic solution. FIG. 16 is a process cross-sectional view illustrating an example of a method for manufacturing a display panel according to the present embodiment. Here, FIG. 16 is a process sectional view in a section taken along line XVH-XVH of the substrate 11 shown in FIG. 15 and 16, the same or equivalent reference numerals are given to the same components as those in the first embodiment described above, and the description thereof is simplified or omitted.

  In the first embodiment described above, the coating mask 21 provided with a plurality of slits 21 a corresponding to the pixels PIX in each column arranged on the display panel 10 (substrate 11) is brought into close contact with the substrate 11. The case where the organic solution 14x is applied along each slit 21a has been described. In the second embodiment, there is a film forming step of applying the organic solution 14x using the coating mask 21 in which the slits 21a are provided in every plurality of rows (for example, 3 rows).

  First, as shown in FIGS. 15A and 15B, the coating mask 21 used in the method for manufacturing a display panel according to the second embodiment is the substrate 11 (or the pixel array region Rpx of the display panel 10). ; See FIG. 3), and has a shape and size extending in the row direction (left and right direction in the drawing; Y direction). The coating mask 21 has slits 21a through which a plurality of pixels PIX (pixel electrodes 12 in the EL element formation region Rel) arranged in the column direction of the substrate 11 (vertical direction in FIG. 15A) are exposed. For example, a plurality of strips are provided every three rows. That is, as shown in FIGS. 15A and 15B, the coating mask 21 is provided such that a plurality of slits 21a are separated by a wide connecting portion 21b.

  Then, the coating mask 21 exposes the EL element formation region Rel (or the pixel electrode 12) of each pixel PIX in columns separated by a plurality of columns (three columns) among the pixels PIX arranged on the substrate 11. The slits 21a are aligned with each other and are in close contact with the surface of the substrate 11. At this time, the connecting portion 21b of the coating mask 21 is in close contact with the partition wall 13 that defines the EL element formation region Rel of the pixel PIX in the column that is not exposed by the slit 21a, and the EL element formation region Rel is covered. Is done. Thereby, in each slit 21a of the coating mask 21, as shown in FIGS. 15A and 15B, the pixel electrode 12 of each pixel PIX arranged in the X direction (or the column direction), and the pixel A part of the partition wall 13 surrounding the electrode 12 is exposed. Then, in this state, as shown in FIGS. 15A and 15B, the substrate placed on the substrate stage 121 while scanning the nozzle head 111 in the X direction (column direction) of the substrate stage 121. 11 is coated with the organic solution 14x.

  In such a display panel manufacturing method according to the present embodiment, red (R) and green (G) are applied to the EL element formation region Rel of the pixel PIX in each adjacent column in the display panel corresponding to color display. , Blue (B) can be satisfactorily applied to the step of forming a light emitting layer of each color.

  Hereinafter, a method for manufacturing a display panel according to the present embodiment (a process for forming an organic EL layer) will be specifically described. First, hole transport is performed to the EL element formation regions Rel of all the pixels PIX arranged on the substrate 11 by using the display panel manufacturing method (organic EL layer forming step) described in the first embodiment. An organic solution containing the material is applied to form a hole transport layer 14a on the pixel electrode 12 (FIGS. 5C, 6D, 6C, 6D, and 7C). (See (d)).

  Next, as shown in FIG. 16A, each of the coating masks 21 is exposed so that the EL element formation region Rel in the column whose emission color is red (R) among the pixels PIX arranged on the substrate 11 is exposed. With the slits 21 a aligned, the coating mask 21 is in close contact with the partition wall 13 of the substrate 11. Next, each EL element in which the hole transport layer 14a is formed in the above-described process by scanning the nozzle head 111R along the slits 21a in a specific column in which the EL element formation region Rel of the red pixel PIX is exposed. An organic solution 14ry containing an electron transporting light emitting material corresponding to the red light emission color is applied and filled in the slit 21a including the formation region Rel.

  Next, the substrate stage 121 is pitch-shifted by a distance corresponding to three columns of the two-dimensionally arranged pixels PIX, thereby aligning the slits 21a in the next column with the nozzle head 111R. Similarly to the above, by scanning the nozzle head 111R, the organic solution 14ry corresponding to the red emission color is applied and filled into the slits 21a of the row. By repeating such application processing, the organic solution 14ry is applied to the EL element formation regions Rel of all the red pixels PIX on the substrate 11.

  Next, the substrate 11 coated and filled with the organic solution 14ry is subjected to reduced pressure and heat treatment, and the organic solution 14ry is dried, thereby, as shown in FIG. 16B, the EL element formation region Rel of each pixel PIX. An electron transporting light emitting layer 14rb corresponding to the red light emission color is formed on the hole transporting layer 14a formed in the above. Thereby, the organic EL layer 14R including the hole transport layer 14a and the electron transport light emitting layer 14rb is formed on the pixel electrode 12 of each red pixel PIX.

  The film forming process of the organic EL layer in the pixel PIX having a specific light emission color is similarly performed for other light emission colors. That is, first, in the substrate 11 on which the electron-transporting light emitting layer 14rb corresponding to the red light emission color is formed as described above, the coating mask 21 that is in close contact with the surface of the substrate 11 is removed (the close contact is released). ) Then, the coating mask 21 is positioned in a state where the slits 21a of the coating mask 21 are aligned so that the EL element forming region Rel of the green (G) emission color is exposed. It adheres again on the partition wall 13 of the substrate 11.

  Next, as shown in FIG. 16C, by scanning the nozzle head 111G along the slit 21a, the EL element formation region Rel of each pixel PIX exposed in the slit 21a corresponds to the green emission color. The organic solution 14gy containing the electron transporting light emitting material is applied and filled. By repeatedly executing such processing on each slit 21a of the coating mask 21, the organic solution 14ry is applied to the EL element formation regions Rel of all the green pixels PIX on the substrate 11. Then, by subjecting the substrate 11 coated and filled with the organic solution 14gy to reduced pressure and heat treatment, as shown in FIG. 16D, the hole transport layer 14a and the green color are formed on the pixel electrode 12 of each pixel PIX. An organic EL layer 14G composed of an electron transporting light emitting layer 14gb corresponding to the emission color of is formed.

  Next, similarly for each pixel PIX whose emission color is blue (B), first, each slit 21a of the coating mask 21 is formed so that the EL element formation region Rel in the column whose emission color is blue (B) is exposed. The coating mask 21 is brought into close contact with the partition wall 13 of the substrate 11 again in the aligned state. Then, as shown in FIG. 16E, the nozzle head 111B is scanned along the slit 21a, and the EL element formation region Rel of each pixel PIX includes an electron transporting light emitting material corresponding to the blue light emitting color. Apply organic solution 14gy. Thereafter, by subjecting the substrate 11 to reduced pressure and heat treatment, as shown in FIG. 16F, the hole transport layer 14a and the electron transport property corresponding to the blue emission color are formed on the pixel electrode 12 of each pixel PIX. An organic EL layer 14B made of the light emitting layer 14bb is formed.

  Therefore, according to the manufacturing method of the display panel according to the present embodiment, the organic EL layer (light emitting layer) of the pixels PIX of RGB colors is formed using the nozzle coating method so as to have a substantially uniform film quality and film thickness. Since a film can be formed, a color display panel excellent in display quality can be mass-produced with high manufacturing efficiency.

  By the way, in the present embodiment, as described above, when the organic solution 14x is applied in the slit 21a, the organic applied on the partition wall 13 provided in the boundary region between the pixels PIX (EL element formation region Rel). It is characterized in that the solution 14x flows evenly into the EL element formation region Rel of the adjacent pixel PIX. On the other hand, in the coating mask 21 applied to each embodiment described above, as shown in FIGS. 8A and 15A, the connecting portions 21b are connected to each other at both ends in the longitudinal direction of the slits 21a. It has a connected planar shape (upper and lower ends of the coating mask 21). Therefore, at the end of each slit 21a, the behavior (how to flow) of the applied organic solution 14x is defined as the region in which the EL element formation regions Rel are arranged adjacent to each other inside the pixel array region Rpx. There is a possibility of difference (see the left and right ends in FIG. 10B).

  Specifically, at the end of each slit 21a, three sides are surrounded by the lyophilic coating mask 21, or the EL element formation region Rel is disposed only on one side of the partition wall 13. Therefore, the amount of the organic solution 14x flowing into the EL element formation region Rel is not equal to the EL element formation region Rel other than both ends of the slit 21a, and the film quality and film thickness may not be uniform (FIG. 10 ( b) Refer to the left and right ends of (f)). Therefore, in such a case, dummy pixels (or dummy EL element formation regions) for evenly flowing the organic solution 14x onto the substrate outside the pixel array region Rpx that substantially contributes to image display. (In this case, in FIGS. 10A to 10F, the pixels arranged at the left and right ends correspond to dummy pixels). According to this, even when the organic EL layer deposition process described in each of the above-described embodiments is applied, the film quality and the film quality of the organic EL layer of the pixel PIX disposed at the end of the pixel array region Rpx The thickness can be made uniform.

<Third Embodiment>
Next, a third embodiment is described for an electronic apparatus to which a display panel (light emitting panel) manufactured using the nozzle coat film forming apparatus (light emitting panel manufacturing apparatus) according to the first and second embodiments described above is applied. A form will be described with reference to the drawings. The display panel 10 provided with the above-described light-emitting elements composed of the organic EL elements OEL in each pixel PIX can be applied to various electronic devices such as a digital camera, a mobile personal computer, and a mobile phone.

  FIG. 17 is a perspective view showing the configuration of the digital camera according to the present embodiment, FIG. 18 is a perspective view showing the configuration of the mobile personal computer according to the present embodiment, and FIG. 19 is the embodiment. It is a figure which shows the structure of the mobile phone which concerns on.

  17, the digital camera 200 generally includes a main body unit 201, a lens unit 202, an operation unit 203, a display unit 204 including the display panel 10 described in each of the above-described embodiments, and a shutter button 205. ing. According to this, in the display unit 204, the light emitting element of each pixel of the display panel 10 emits light with an appropriate luminance gradation according to the image data, so that good and uniform image quality can be realized.

  In FIG. 18, the personal computer 210 generally includes a main body unit 211, a keyboard 212, and a display unit 213 including the display panel 10 described in each of the above-described embodiments. Even in this case, in the display unit 213, the light emitting elements of the respective pixels of the display panel 10 perform the light emission operation with an appropriate luminance gradation corresponding to the image data, so that a good and uniform image quality can be realized.

  In FIG. 19, the cellular phone 220 generally includes an operation unit 221, an earpiece 222, a mouthpiece 223, and a display unit 224 including the display panel 10 described in each of the above-described embodiments. . Even in this case, in the display unit 224, the light emitting elements of the respective pixels of the display panel 10 perform the light emission operation with an appropriate luminance gradation according to the image data, so that a good and uniform image quality can be realized.

  In each of the above-described embodiments, the case where the present invention is applied to the display panel 10 having the light emitting element composed of the organic EL element OEL in each pixel PIX has been described. However, the present invention is not limited to this. That is, the present invention includes a light emitting element array in which a plurality of pixels PIX each having a light emitting element made of, for example, an organic EL element OEL are arranged in one direction, and light emitted from the light emitting element array on a photosensitive drum according to image data. It may be applied to an exposure apparatus that performs exposure by irradiating. Even in this case, since the light emitting element of each pixel of the light emitting element array can be caused to emit light at an appropriate luminance according to the image data, a good exposure state can be realized.

  Further, in each of the above-described embodiments, the case where the organic EL layer 14 includes the hole transport layer 14a and the electron transport light-emitting layer 14b has been described as the element structure of the organic EL element OEL. However, the present invention is limited to this. Is not to be done. That is, the organic EL element OEL applied to the present invention may be one in which the organic EL layer 14 has an element structure composed of, for example, a hole transporting / electron transporting light emitting layer only, or a hole transporting light emitting layer and an electron. It may be composed of a transport layer, a charge transport layer may be appropriately interposed between these layers, and a combination of other charge transport layers may be further included.

  In each of the above-described embodiments, the case where ink is applied while the nozzle head 111 is scanned in the X direction has been described. However, the present invention is not limited to this. That is, the nozzle head 111 may be fixed and the ink may be applied while the substrate stage 121 on which the substrate 11 is placed is scanned in the X direction. In each of the above-described embodiments, the case where the nozzle head 111 moves in the two-dimensional coordinate direction relative to the substrate 11 by moving the substrate 11 in the Y direction has been described. It is not limited. That is, the substrate stage 121 may be fixed and the nozzle head 111 may be moved in the two-dimensional coordinate direction relative to the substrate 11 by moving the nozzle head 111 in the Y direction.

DESCRIPTION OF SYMBOLS 11 Substrate 12 Pixel electrode 13 Partition 14 Organic EL layer 14a Hole transport layer 14b Electron transporting light emitting layer 14x Organic solution 15 Counter electrode 21 Application mask 21a Slit 21b Connection portion 21c Adhesion surface 100 Nozzle coating film forming apparatus 111 Nozzle head 115 Head Scanning Unit 121 Substrate Stage PIX Pixel OEL Organic EL Element Rel EL Element Formation Area

Claims (9)

Production of a light emitting panel comprising a light emitting element in which a first electrode, a light emitting functional layer consisting of at least one layer, and a second electrode are laminated on a substrate, and at least a plurality of pixels arranged in a specific row are arranged In the device
A nozzle that discharges and applies ink to each formation region of the pixel set on the substrate;
A mask adhesion control unit that removably adheres a mask adhesion surface having an opening through which at least two pixel formation regions in the specific row are exposed;
An apparatus for manufacturing a light-emitting panel, comprising:   The light emitting panel manufacturing apparatus according to claim 1, wherein the contact surface of the mask has liquid repellency.   The apparatus for manufacturing a light-emitting panel according to claim 1, further comprising an ink drying processing unit that heat-treats the substrate coated and filled with the ink in a reduced pressure state.   The said mask is provided with the said multiple opening part corresponding to the formation area of all the said pixels arranged on the said board | substrate, It is any one of Claim 1 thru | or 3 characterized by the above-mentioned. The manufacturing apparatus of the light emission panel of description.   4. The mask according to claim 1, wherein the mask is provided with a plurality of openings corresponding to only the formation regions of the pixels in a specific column arranged on the substrate. 5. The manufacturing apparatus of the light emission panel of one term | claim. The mask is made of a magnetic material,
The light emitting panel manufacturing apparatus according to claim 1, wherein the mask adhesion control unit draws the mask close to the substrate by a magnetic force. A plurality of pixels each including a light emitting element in which a first electrode, a light emitting functional layer including at least one layer, and a second electrode are stacked on a substrate, and a partition wall that defines each formation region of the plurality of pixels are provided. In the manufacturing method of the light emitting panel,
A step of bringing a formation surface of the plurality of pixels arranged in a column direction on the substrate to be exposed, and an adhesion surface of a mask provided with a plurality of openings having lyophilic properties on the partition; When,
Discharging ink while scanning a nozzle along the opening, and applying and filling the ink in the opening; and
Drying the substrate coated and filled with the ink to form a light emitting functional layer of the pixel;
A method for manufacturing a light-emitting panel, comprising: The mask is provided with the opening corresponding to only the formation region of the pixel in a specific column arranged on the substrate,
The mask is attached to and detached from the partition, the opening is moved to a different row on the substrate, and the ink is applied and filled in the opening, and the substrate is heated. The method of manufacturing a light-emitting panel according to claim 7, wherein the step is repeatedly executed.   9. An electronic device on which a light-emitting panel formed by applying the manufacturing method according to claim 7 or 8 is mounted.

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