JP2018101532A - Manufacturing method of organic el display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress expansion of color mixture due to an extraneous material adhering to a bank, while reducing the number of demerit points resulting from repair of the bank, in the manufacture of organic EL display panel.SOLUTION: A manufacturing method of organic EL display panel includes a step of forming a bank elongating on a board in the column direction, a step of detecting an extraneous material existing while superposing the bank in the plan view of the board, a step of determining whether or not repair is required for a bank on the periphery of the detected extraneous material, and a step of repairing the bank according to the determination results. In the determination step, if a bank exists below the detected extraneous material, a determination is made that repair is required when the ratio of the width of the extraneous material to the width of the bank is larger than α1, and if a bank exists above the detected extraneous material, a determination is made that repair is required when the ratio of the width of the extraneous material to the width of the bank is larger than or equal to α2 that is larger than α1.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a method for manufacturing an organic EL display panel in which organic EL (Electro Luminescence) elements using an electroluminescence phenomenon of an organic material are arranged in a matrix, and particularly to a step of forming a bank.

  In recent years, organic EL display panels have been put into practical use as light-emitting display devices. In the organic EL display panel, each organic EL element has a basic structure in which a light emitting layer containing an organic light emitting material is disposed between a pair of electrodes of an anode and a cathode. This is a current-driven light-emitting element that is generated by recombination of holes injected from the anode into the light-emitting layer and electrons injected from the cathode into the light-emitting layer.

In manufacturing an organic EL display panel, a substrate is partitioned by banks, and a light emitting layer is formed in each partition. The bank is formed by patterning into a bank shape by a photolithography method using a photosensitive thermosetting resin, followed by heating and baking.
For forming the light emitting layer, a wet method is often used in which ink for forming a light emitting layer containing a polymer material or a low molecule having good thin film formability is applied to a concave space by an inkjet method or the like. According to this wet method, an organic functional layer including a light emitting layer can be formed relatively easily even in a large panel.

JP-A-2006-71992

  If foreign matter adheres to the bank in the manufacturing process of the organic EL display panel as described above, when forming the light emitting layer, different color inks applied across the bank where the foreign matter is present are mixed to form a mixed color. May occur. In particular, in a configuration in which a bank extending in the column direction is provided, this color mixture is enlarged to a plurality of pixels along the bank, which may cause a serious display defect.

Thus, for example, Patent Document 1 discloses a technique for suppressing the expansion of color mixture in a display panel by repairing a bank to which foreign matter has adhered.
However, if a repair material is applied to the foreign matter adhered to the bank and repaired, the shape of the bank may collapse around the repaired portion. When the shape of the formed bank collapses, the light emitting layer formed between the banks is not formed into the original shape, causing a “dark spot” that the light emitting layer does not emit light (pixel does not emit light).

As described above, when the bank is repaired to suppress the expansion of the mixed color, dark spots are generated. However, it is desirable that the number of dark spots is small in order to improve the image quality of the organic EL display panel.
In view of the above-described problems, the present disclosure suppresses expansion of color mixture due to foreign matters attached to a bank in the manufacturing process of the organic EL display panel, and reduces the number of dark spots resulting from repair of the bank. An object is to provide a manufacturing method.

  A method for manufacturing an organic EL display panel according to an aspect of the present disclosure is a method for manufacturing an organic EL display panel in which a substrate is partitioned by a plurality of banks, and a light emitting layer is formed in each partition. A step of forming banks extending in the column direction, a step of detecting foreign matter existing in a state of overlapping with the bank when the substrate is viewed in plan, and whether or not repair is necessary for the bank around the detected foreign matter. And a step of repairing the bank according to the determination result. In the determining step, if a bank exists below the detected foreign object, it is determined that repair is necessary when the ratio of the foreign object width to the bank width is greater than α1, and there is a bank above the detected foreign object. In this case, when the ratio of the width of the foreign object to the width of the bank is equal to or larger than α2 which is larger than α1, it is determined that repair is necessary.

  According to the manufacturing method of the organic EL display panel of the present disclosure, it is possible to suppress the expansion of the color mixture due to the foreign matter attached to the bank and to reduce the number of dark spots caused by the repair of the bank.

It is a schematic block diagram which shows the structure of an organic electroluminescence display. It is a top view which shows typically the schematic structure seen from the display surface side of the display panel. It is the partially expanded sectional view which cut | disconnected the display panel by the A-A 'line. It is a schematic process diagram which shows the manufacturing process of a display panel. It is sectional drawing which shows a bank formation process typically. It is a figure which shows typically the foreign material adhering to a bank. It is a figure which shows typically that color mixing has generate | occur | produced in the comparative example which does not form a weir. It is a schematic block diagram which shows an example of the repair apparatus used for the detection of a foreign material, and its repair. It is a figure which shows typically the calculation method of the overlapping degree to the bank of a foreign material. It is a figure which shows an example of the flowchart which determines whether repair of a bank is performed. It is a figure which shows typically the weir formed by repair of a bank. It is a figure which shows the application | coating position set in the image around a defect part. It is a figure which shows a mode that a weir is formed by apply | coating a repair material. It is a figure which shows that the range of a color mixing area | region is restrict | limited by forming a weir.

<< Summary of Embodiment >>
A method for manufacturing an organic EL display panel according to aspect 1 of the present disclosure is a method for manufacturing an organic EL display panel in which a substrate is partitioned by a plurality of banks, and a light emitting layer is formed in each partition. A step of forming banks extending in the column direction, a step of detecting foreign matter existing in a state of overlapping with the bank when the substrate is viewed in plan, and whether or not repair is necessary for the bank around the detected foreign matter. And a step of repairing the bank according to the determination result. In the determining step, if a bank exists below the detected foreign object, it is determined that repair is necessary when the ratio of the foreign object width to the bank width is greater than α1, and there is a bank above the detected foreign object. In this case, when the ratio of the width of the foreign object to the width of the bank is equal to or larger than α2 which is larger than α1, it is determined that repair is necessary.

With such a configuration, it is possible to suppress the expansion of the color mixture due to the foreign matter attached to the bank and reduce the number of dark spots resulting from the repair of the bank.
The method for manufacturing an organic EL display panel according to aspect 2 of the present disclosure is characterized in that α1 is 0 and α2 is 0.5 in the method for manufacturing an organic EL display panel according to aspect 1.
With such a configuration, it is possible to appropriately determine whether or not the repair is performed according to the size of the foreign matter attached to the bank.

  The organic EL display panel according to Aspect 3 of the present disclosure is a method for manufacturing an organic EL display panel according to Aspect 1 or Aspect 2. By detecting the foreign matter before the step of forming a bank in the step of detecting the foreign matter. Foreign matter existing below the bank is detected, and foreign matter existing above the bank is detected by detecting foreign matter after the step of forming the bank.

With such a configuration, it is possible to distinguish and detect foreign matter existing above the bank and foreign matter existing below the bank.
<< Embodiment >>
[1. Configuration of organic EL display panel]
FIG. 1 is a schematic block diagram illustrating a configuration of an organic EL display device 1 having a display panel 100 according to the first embodiment.

  As shown in FIG. 1, the organic EL display device 1 includes a display panel 100 and a drive control unit 101 connected thereto. The display panel 100 is a panel using an electroluminescence phenomenon of an organic material, and a plurality of organic EL elements 10 are arranged in a matrix on a substrate. The drive control unit 101 includes four drive circuits 102 to 105 and a control circuit 106.

The arrangement of the drive control unit 101 with respect to the display panel 100 is not limited to this.
FIG. 2 is a plan view schematically showing a schematic configuration viewed from the display surface side of the display panel 100. 3 is a partially enlarged cross-sectional view of the display panel 100 taken along the line AA ′ of FIG. The display panel 100 is a so-called top emission type, and has a display surface on the Z direction side.

  As shown in FIG. 3, the display panel 100 includes, as main components, a base substrate 11, a pixel electrode 12, a hole injection layer 13, a bank 14, an organic light emitting layer 15, an electron transport layer 16, a common electrode 17, and a sealing. Layer 18 is provided. Then, the organic EL element 10 having the organic light emitting layer 15 corresponding to any one of the emission colors of red (R), green (G), and blue (B) is set as a sub pixel, and as shown in FIG. Arranged in a matrix.

2 shows a state in which the electron transport layer 16, the common electrode 17, and the sealing layer 18 are removed.
[2. Materials for organic EL display panel]
(1) Base Substrate The base substrate 11 includes a substrate body 11a, a TFT (thin film transistor) layer 11b, and an interlayer insulating layer 11c.

The substrate body 11a is a part that becomes a base material of the display panel 100, and can be formed of any of insulating materials such as alkali-free glass, soda glass, polycarbonate resin, polyester resin, and alumina.
The TFT layer 11b is provided for each subpixel on the surface of the substrate main body 11a, and a pixel circuit including a thin film transistor element is formed in each.

  The interlayer insulating layer 11c is formed on the TFT layer 11b. The interlayer insulating layer 11c is made of an organic insulating material such as polyimide resin, acrylic resin, or novolak type phenol resin, or an inorganic insulating material such as SiO (silicon oxide) or SiN (silicon nitride). The TFT layer 11b and the pixel electrode 12 are formed. And has a function of flattening even if a step exists on the upper surface of the TFT layer 11b and suppressing the influence on the base surface on which the pixel electrode 12 is formed.

(2) Pixel electrode The pixel electrode 12 is a pixel electrode provided for each sub-pixel. For example, Ag (silver), Al (aluminum), aluminum alloy, Mo (molybdenum), APC (silver, palladium, It is made of a light reflective conductive material such as a copper alloy. In the present embodiment, the pixel electrode 12 is an anode.

A known transparent conductive film may be further provided on the surface of the pixel electrode 12. As a material of the transparent conductive film, for example, indium tin oxide (ITO) or indium zinc oxide (IZO) can be used. The transparent conductive film is interposed between the pixel electrode 12 and the hole injection layer 13 and has a function of improving the bonding property between the respective layers.
(3) Hole injection layer The hole injection layer 13 is made of, for example, silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), iridium (Ir), or the like. It is a layer made of a conductive polymer material such as an oxide or PEDOT (a mixture of polythiophene and polystyrene sulfonic acid). Among the above, the hole injection layer 13 made of metal oxide has a function of injecting and transporting holes to the organic light emitting layer 15 in a stable manner or assisting the generation of holes.

(4) Bank On the surface of the hole injection layer 13, a plurality of strip-shaped banks 14 are provided in parallel in a plan view extending in the Y direction. The bank 14 is made of an insulating organic material (for example, an acrylic resin, a polyimide resin, a novolac type phenol resin, or the like).
As the bank material, a composition made of a thermosetting resin that is cured by applying heat is used. The composition includes a photopolymerization initiator that initiates polymerization by irradiation with UV light.

As a kind of resin, the thermosetting resin which has ethylenic double bonds, such as a (meth) acryloyl group, an allyl group, a vinyl group, a vinyloxy group, is mentioned, for example. Moreover, you may add the crosslinking agent which bridge | crosslinks with respect to these resin, for example, an epoxy compound, a polyisocyanate compound.
Further, a fluorinated polymer containing fluorine may be introduced into the resin structure. Examples of the fluorinated polymer include a photosensitive resist containing a fluorinated resin such as a fluorinated polyolefin resin, a fluorinated polyimide resin, and a fluorinated polyacrylic resin.

Specific examples of the resin into which the fluorinated polymer is introduced include Lumiflon (registered trademark, Asahi Glass), which is a copolymer of fluoroethylene and vinyl ether.
Alternatively, an ink repellent agent may be added to the resin.
The cross section of each bank 14 is trapezoidal as shown in FIG. 3, and a groove space defined by the bank 14 is formed between the banks 14, and the organic light emitting layer 15 is formed there. .

The bank 14 functions as a structure that prevents the applied ink from overflowing when the organic light emitting layer 15 is formed by a wet method.
(5) Repair material When a foreign object is detected in the bank 14, the repair of the bank 14 is performed using the repair material.
As the repair material, a resin composition that is cured by applying light or heat can be used.

Examples of the resin include curable resins having an ethylenic double bond such as a (meth) acryloyl group, an allyl group, a vinyl group, and a vinyloxy group.
Moreover, you may add the crosslinking agent which bridge | crosslinks with respect to resin, for example, an epoxy compound and a polyisocyanate compound.
Moreover, you may use the fluoropolymer in which the fluorine was introduce | transduced in this resin structure.

By introducing fluorine into the resin of the repair material, ink repellency can be imparted to the formed weir 5. Alternatively, various ink repellent agents may be added to the resin.
Note that, as the resin for the repair material, the same resin as the bank material for forming the bank molded body 14a may be used. However, in the case of the bank material, an acid component soluble in the alkali developer is contained, but it is preferable that the repair material forming the weir does not contain an acid component soluble in the alkali developer. This is because the development is not performed when the weir molded body 5a is formed, and the solvent resistance of the weir 5 is reduced when the acid component remains in the weir 5.

To the repair material, a solvent and a photopolymerization initiator are appropriately added to such a resin composition.
As a solvent, it has the solubility with respect to resin, The solvent whose boiling point is about 150-250 degreeC can use 1 type, or 2 or more types.
Various commercially available photopolymerization initiators can be used as the photopolymerization initiator.
(6) Organic Light-Emitting Layer The organic light-emitting layer 15 is a site where carriers (holes and electrons) recombine and emits light, and includes an organic material corresponding to any color of R, G, and B.

The organic light emitting layer 15 is formed in a groove-like concave space (groove space 20 in FIG. 6) that extends in the Y direction and is partitioned by the bank 14.
The organic light emitting layers 15 having different colors are arranged with the bank 14 in between.
Examples of the material of the organic light emitting layer 15 include polyparaphenylene vinylene (PPV), polyfluorene, oxinoid compound, perylene compound, coumarin compound, azacoumarin compound, oxazole compound, oxadiazole compound, perinone compound, pyrrolopyrrole compound, naphthalene. Compound, anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenanthrene compound, cyclopentadiene compound, stilbene compound, diphenylquinone Compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound , Fluorescein compound, pyrylium compound, thiapyrylium compound, serenapyrylium compound, telluropyrylium compound, aromatic ardadiene compound, oligophenylene compound, thioxanthene compound, cyanine compound, acridine compound, 8-hydroxyquinoline compound metal complex, 2-bipyridine compound And a fluorescent substance such as a complex of a Schiff salt and a group III metal, an oxine metal complex, or a rare earth complex.

(7) Electron Transport Layer The electron transport layer 16 has a function of transporting electrons injected from the common electrode 17 to the organic light emitting layer 15. For example, an oxadiazole derivative (OXD), a triazole derivative (TAZ), a Fe It is formed of a nansuloline derivative (BCP, Bphen) or the like.
(8) Common electrode The common electrode 17 is formed of, for example, a light-transmitting material having conductivity, such as ITO or IZO, and is provided over all subpixels.

In the present embodiment, the common electrode 17 is a cathode.
(9) Sealing Layer The sealing layer 18 is provided to protect the hole injection layer 13, the organic light emitting layer 15, the electron transport layer 16, and the common electrode 17 from moisture and oxygen.
Although not shown, a black matrix, a color filter, or the like may be formed on the sealing layer 18.
[3. Manufacturing method of organic EL display panel]
FIG. 4 is a schematic process diagram showing the manufacturing process of the display panel 100.

FIG. 5 is a cross-sectional view schematically showing a bank forming process in the manufacturing process of the display panel 100.
A method of manufacturing the display panel 100 will be described with reference to FIG. 5 based on the process diagram of FIG.
First, the base substrate 11 is prepared. The base substrate 11 can be manufactured by a known TFT manufacturing method.

Next, the pixel electrode 12 made of a metal material having a thickness of about 400 [nm] is formed on the base substrate 11 for each sub-pixel by vacuum deposition or sputtering. Subsequently, the hole injection layer 13 is formed by uniformly depositing tungsten oxide on the base substrate 11 and the pixel electrode 12 by sputtering or the like (step S1).
Next, the bank 14 is formed (steps S2 to S8).

First, the presence / absence of foreign matter on the hole injection layer 13 is examined, and if there is a foreign matter, its position and size are calculated (step S2). A method for detecting a foreign object will be described later.
Next, a negative photosensitive resin composition is prepared as a bank material, and this bank material is uniformly applied on the hole injection layer 13 as shown in FIG. Then, the applied bank material layer is patterned into a bank shape by photolithography (step S3). That is, as shown in FIG. 5B, a mask having an opening corresponding to the pattern of the bank 14 to be formed is overlaid on the bank material layer and exposed from above the mask.

Thereafter, the bank material is patterned by washing out the excess bank material with an alkaline developer to form a bank pattern. As shown in FIG. 5 (c), a bank molded body 14 a (unfired bank) is pattern-formed on the base substrate 11. A groove space 20 is formed between adjacent bank molded bodies 14a.
Next, the formed bank molded body 14a is heated and pre-baked (step S4). As a heating method at the time of pre-baking, for example, as shown in FIG. 5D, in a hot air drying furnace, hot air is applied to the bank molded body 14 a formed on the base substrate 11 to heat it. In addition, it can also carry out by the method of irradiating a heat ray with an infrared lamp, and the method of heating with a hot plate.

Next, the presence or absence of foreign matter in each bank molded body 14a is checked, and if there is a foreign matter, its position and size are calculated (step S5).
When foreign matter is detected in step S2 or step S5, it is determined whether or not bank repair is necessary for the detected foreign matter (step S6). The determination method will be described later.

  If it is determined in step S6 that bank repair is necessary, bank repair is performed (step S7). Although this bank repair will be described in detail later, in the vicinity of the detected foreign matter 3, a repair material is applied to the groove space 20 between the bank molded bodies 14a and dried. FIG. 5E shows a state where the repair material is applied to the groove space 20 adjacent to the bank molded body 14a where the foreign material 3 exists, and the dam molded body 5a is formed.

  Thereafter, as shown in FIG. 5 (f), the bank molded body 14a and the weir molded body 5a are heated and subjected to main firing, whereby the bank 14 and the weir 5 are completed, and the repair of the foreign matter 3 is completed (step) S8). In the main firing, the bank molded body 14a and the dam molded body 5a are heated to complete the polymerization reaction of the thermosetting resin. As a heating method, as in the case of the pre-baking, in addition to a method in which hot air is applied to the bank molded body 14a formed on the base substrate 11 in a hot air drying furnace, a method of irradiating heat rays with an infrared lamp, A method of heating with a hot plate can be used.

FIG. 5F shows a state in which the bank 14 is formed and the weir 5 is formed by the main firing, that is, a state in which the repaired bank 14 is formed.
The bank 14 thus formed may be further subjected to a process of adjusting the contact angle of the surface of the bank 14 with respect to the ink applied in the next step. Alternatively, in order to impart liquid repellency to the surface of the bank 14, a surface treatment may be performed with a predetermined alkaline solution, water, an organic solvent, or the like, or a plasma treatment may be performed.

Subsequently, ink for forming a light emitting layer is applied to the groove space 20 between the banks 14. This ink is a mixture of an organic material constituting the organic light emitting layer 15 and a solvent, and is applied to each groove space 20 by an ink jet method.
Then, the solvent contained in the applied ink layer 15a is evaporated and dried, and the organic light emitting layer 15 is formed in each groove space 20 by heating and baking as necessary (step S9).

Next, the electron transport layer 16, the common electrode 17, and the sealing layer 18 are formed in order on the organic light emitting layer 15 and the bank 14 (step S10). For example, the electron transport layer 16 is formed by a vacuum evaporation method, the common electrode 17 is formed by a material such as ITO or IZO by a sputtering method, and the sealing layer 18 is light transmissive such as SiN or SiON. The material is formed by sputtering or CVD.
The display panel 100 is completed through the above steps.
[4. Bank foreign object]
The foreign matter adhering to the bank molded body will be described with reference to FIG.

In the example shown in FIG. 6A, the foreign matter 3 is adhered on one bank molded body 14a.
In this way, if there is foreign matter on the bank molded body 14a, ink is applied to the adjacent groove space 20 across the bank 14 to form the ink layer 15a that is piled up in a dome shape, and the ink layer 15a becomes foreign matter. There is a possibility that inks having different emission colors (for example, red ink and green ink) are mixed and a mixed color region as shown in FIG. 7 is generated.

In the example shown in FIG. 6B, the foreign matter 3 enters under one bank molded body 14a, and the foreign matter penetrates to the adjacent groove space.
As described above, even when foreign matter is present under the bank molded body 14a, when the adhesion between the foreign matter and the bank material is poor, a gap is formed to form an ink flow path, or the foreign matter is a fiber piece. Absorbs ink, so that the foreign matter itself becomes an ink flow path. Therefore, color mixing occurs between the ink layers 15a formed in adjacent groove spaces with the foreign matter in between, which causes a color mixing region as shown in FIG.

As described above, in the bank molded body 14a, the foreign matter adheres to the mixed color of inks having different emission colors, which causes the emission color defect.
[5. Foreign object detection method]
The foreign object detection method in steps S2 and S5 in FIG. 4 will be described with reference to FIGS. FIG. 8 is a schematic configuration diagram illustrating an example of a repairing apparatus 200 used for detecting a foreign object and repairing the foreign object.

The detection of the foreign material 3 is performed by, for example, taking a surface image of the hole injection layer 13 formed in step S1 or a surface image of the pre-baked bank molded body 14a in step S4 and performing pattern inspection of the surface image.
The repair device 200 has a table 202 on which the base substrate 11 is placed on a base 201, and a head unit 210 to which an imaging element 211 and a dispenser 212 are attached. The table 202 can be moved in the Y direction based on an instruction from the controller 230, and the head unit 210 can be moved in the X direction and the Z direction according to an instruction from the controller 230.

Accordingly, the image pickup device 211 and the dispenser 212 attached to the head unit 210 are in the X direction and Y direction with respect to the base substrate 11 above the base substrate 11 placed on the table 202 according to an instruction from the controller 230. Direction relative to the Z direction.
Using the repair device 200, image data on the upper surface of the base substrate 11 is acquired while moving the imaging device 211 along the upper surface of the base substrate 11, and stored in the storage unit 231 of the controller 230.

  The controller 230 detects the foreign matter 3 by comparing the image data with the template data stored in advance in the storage unit 231 and detecting a difference. When the foreign material 3 is detected, the position of the detected foreign material 3 (the position of the center O of the foreign material 3 in the X direction and the Y direction) and the degree of overlap α of the foreign material on the bank molded body 14a are stored in the storage unit 231. To do.

The degree of overlap α of foreign matter on the bank molded body 14a will be described.
The degree of overlap α of the foreign matter on the bank formed body 14a is the ratio L2 of the width L2 in the X direction of the overlap region when viewed from above the foreign matter 3 and the bank formed body 14a with respect to the width L1 in the X direction of the bank formed body 14a. / L1.
FIG. 9A is a view showing an example of a state in which the foreign matter 3 is attached on the bank molded body 14a, and the upper view of FIG. 9A is a top view, and FIG. The following figure is a side view. FIG. 9B is a diagram illustrating an example of a state in which the foreign matter 3 exists under the bank molded body 14a, and an upper view of FIG. 9B is a top view, and FIG. The following figure is a side view.

When the region of the foreign material 3 is included in the region of the bank molded body 14a when viewed from above as shown in FIG. 9A, the distance in the X direction between the end points X1 and X2 in the X direction of the region of the foreign material 3 is L2.
As shown in FIG. 9B, when the region of the foreign matter 3 exists outside the region of the bank molded body 14a when viewed from the top, the end point X3 in the X direction of the region of the foreign matter 3 and the X of the bank molded body 14a. The distance in the X direction between the direction end point X4 is L2.

The controller 230 calculates L2 from the acquired image data, and calculates the degree of overlap α = L2 / L1 of the foreign matter 3 on the bank molded body 14a using the width L1 of the bank molded body 14a.
In such a detection step, the foreign matter 3 may be detected or the foreign matter 3 may not be detected.

By performing foreign object detection before forming the bank molded body 14a in step S2 of FIG. 4, it exists below the bank molded body 14a shown in FIG. 9B, that is, between the bank molded body 14a and the base substrate 11. The foreign material 3 to be detected is detected. Further, the foreign matter 3 existing above the bank formed body 14a shown in FIG. 9A is detected by detecting the foreign matter after forming the bank formed body 14a in step S5 of FIG.
[6. Bank repair judgment]
Even if the foreign matter 3 adheres to the bank molded body 14a, ink color mixture does not always occur. Therefore, in the manufacturing method of the organic EL panel according to the present embodiment, it is determined whether or not the detected foreign matter 3 needs to be repaired in the bank, and the foreign matter that has been determined to need repair in the bank is determined. Only repair the bank.

FIG. 10 is an example of a flowchart of a determination process for determining whether or not the bank repair performed by the repair apparatus 200 is necessary.
First, it is determined whether the detected foreign matter 3 is a foreign matter that exists above the bank molded body 14a or a foreign matter that exists below the bank molded body 14a (step S21). In other words, it is determined whether the bank molded body 14 a exists below the foreign material 3 or whether the bank molded body 14 a exists above the foreign material 3.

When the detected foreign matter 3 is a foreign matter existing above the bank formed body 14a, or when the bank formed body 14a exists below the foreign matter 3, the degree of overlap α (= It is determined whether or not (L2 / L1) is larger than α1 (step S22).
In step S22, when the degree of overlap α of the foreign matter 3 on the bank molded body 14a is larger than α1, it is determined that the bank needs to be repaired (step S24).

In step S22, if the degree of overlap α of the foreign matter 3 on the bank molded body 14a is α1 or less, it is determined that bank repair is unnecessary (step S25).
When the detected foreign matter 3 is a foreign matter existing below the bank molded product 14a, or when the bank molded product 14a exists above the foreign matter 3, the degree of overlap α (= It is determined whether or not (L2 / L1) is α2 or more (step S23).

In step S23, when the overlapping degree α of the foreign matter 3 to the bank molded body 14a is α2 or more, it is determined that the bank needs to be repaired (step S26).
In step S23, when the degree of overlap α of the foreign matter 3 on the bank molded body 14a is smaller than α2, it is determined that the repair of the bank is unnecessary (step S27).
Compared with the case where the foreign matter 3 is present above the bank molded body 14a, the color mixture of the ink is present below the bank molded body 14a, that is, when the foreign matter 3 exists between the bank molded body 14a and the base substrate 11. The experimental result that it is hard to generate is obtained. Therefore, α2 is set to a value larger than α1. α1 is preferably set in the range of 0 to 0.25. In this embodiment, α1 = 0. α2 is preferably set in the range of 0.25 to 0.75. In the present embodiment, α1 = 0.5.
[7. Bank repair method]
A bank repair process executed when it is determined that the bank needs to be repaired will be described.

A weir forming repair material is applied from the dispenser 21 so as to surround the foreign material 3 on the base substrate 11 placed on the table 202 in the repair device 200 shown in FIG. By doing so, the bank molded body 14a is repaired.
Here, as shown in FIG. 11, the foreign matter 3 comes from the two points A <b> 1 and A <b> 2 sandwiching the foreign matter 3 in the Y direction in each groove space 20 adjacent to both sides of the bank formed body 14 a having the foreign matter 3. The dam molded body 5a is formed in a shape extending over the bank molded body 14a adjacent to the existing bank molded body 14a. That is, a total of four dam-shaped bodies 5 a partitioned in the X direction are formed in the groove space 20 surrounding the foreign material 3.

The dispenser 212 provided in the repair device 200 is a needle-type dispenser, and a tank 214 that stores a repair material is attached to a tip portion thereof, and the needle 213 moves up and down so as to penetrate the tank 214. The repair material adhered to the needle 213 can be applied in units of microliters.
The needle 213 in the dispenser 212 is driven based on a control signal from the controller 230.

The formation of the dam body 5a is performed by applying a repair material from the dispenser 212 to a plurality of positions set along a line (weir formation line) in which the dam 5 is to be formed in the groove space 20.
In the controller 230 of the repairing apparatus 200, the image data of the bank formed body 14a and the position of the foreign material 3 are stored as described above, so that the position set around the foreign material 3 can be accurately set based on the position. Can be applied.

FIG. 12A is a diagram showing the application position set around the foreign material 3 in this image.
As shown in the figure, in the groove space 20 adjacent to both sides of the bank molded body 14a having the foreign material 3, the center portion of the foreign material 3 is set as a reference O and passes through a point A1 which is a distance a1 away in the Y direction. Application points P1, P2, P3, and P4 are set along a weir formation line extending in the direction and a weir formation line extending in the X direction through a point A2 separated by a distance a2 in the direction opposite to the Y direction. .

Here, the distance a1 and the distance a2 may be the same or different from each other. However, the distance a1 and the distance a2 are set to an appropriate length so that the entire foreign matter 3 is sandwiched between the points A1 and A2 and is not too large. Set.
FIG. 12B is a diagram schematically showing a cross section along the weir formation line passing through the point A <b> 1 in the base substrate 11.

The repair device 200 forms the weir molded body 5a by sequentially applying repair materials with the needle 213 at the application points P1, P2, P3, and P4 set as described above.
13 (a) to 13 (g) are diagrams showing how the weir molded body 5a is formed by sequentially applying repair materials to the application points P1, P2,...
First, as shown in FIGS. 13A and 13B, the needle 213 and the tank 214 are positioned at the application point P1, and the needle 213 is moved downward to attach the repair material to the needle 213. The repair material is applied to the application point P1 by approaching the application point P1.

The repair material has fluidity until it is applied, but after the application, the mountain shape is maintained, and as shown in FIG. 13C, a pile of the repair material is formed at the application point P1.
Subsequently, as shown in FIG. 13D, the needle 213 is pulled up into the tank 241 and the needle 213 and the tank 214 are moved to the application point P2. Then, the repair material is applied to the application point P2 by moving the needle 213 downward and bringing the needle 213 to which the repair material is attached closer to the application point P2.

As a result, as shown in FIG. 13E, the pile of the repair material formed at the application point P2 is connected to the pile of the repair material formed at the application point P1.
Subsequently, as shown in FIG. 13 (f), the needle 213 is pulled up and moved to the application point P3. Similarly, a pile of repair material is formed at the application point 3 and is connected to the pile of repair material at the application point P2.

In this way, the piles of repair materials are connected in a shape extending from the point A1 on the bank molded body 14a having the foreign material 3 to the adjacent bank molded body 14a. Then, the applied pile of repair material is dried and exposed as necessary to form the weir molded body 5a.
In the subsequent main firing step, the applied repair material is cured, so that the weir 5 having more stable physical properties is formed.

As shown in FIG. 11, each of the groove spaces 20 on both sides of the bank 14 having the foreign material 3 is provided with a pair of weirs 5, and the groove space 20 is a space close to the foreign material 3 by the weir 5. It is partitioned into a first space SA made up of parts and two second spaces SB made up of space parts that are not close to the foreign matter 3. The foreign material 3 is surrounded by the two first spaces SA.
As described above, after the foreign matter 3 in the bank 14 is repaired and the organic light emitting layer 15 is formed in each groove space 20 in the organic light emitting layer forming step of the next step S9, the first space SA and the second space SB are formed. Also, the ink is applied to form the organic light emitting layer 15. Therefore, in the panel after the light emitting layer is formed, the organic light emitting layer 15 formed in the first space SA and the organic light emitting layer 15 formed in the second space SB are partitioned by the weir 5. It becomes.

  FIG. 14 shows the organic EL display panel according to the present embodiment. After the weir 5 is formed around the bank molded body 14 having the foreign material 3, a red space is formed in one groove space 20 adjacent to the bank 14. FIG. 6 is a plan view showing a state in which ink is applied to form an ink layer 15a (R) and green ink is applied to the other groove space 20 to form an ink layer 15a (G). FIG. 7 is a plan view showing a state in which the ink layer 15a (R) and the ink layer 15a (G) are formed in the adjacent groove space 20 with the bank 14 in the same manner in the comparative example in which the weir 5 is not formed. It is.

As shown in FIG. 7, if the weir 5 is not formed around the bank 14 having the foreign matter 3, the mixed color region formed by mixing the red ink and the blue ink through the foreign matter 3 is in each ink layer 15 a. Spread with. This color mixture region may extend long in the Y direction, and its length may be about 1 cm.
As shown in FIG. 14, when the weir 5 is formed around the bank 14 having the foreign matter 3, the groove space 20 includes the first space SA that is close to the foreign matter 3 sandwiched between the pair of weirs 5, and the weir It is partitioned into two second spaces SB that are not close to the foreign matter 3 outside the pair of five. Therefore, as shown in FIG. 13, the color mixture area is limited to the range of the first space SA.
[8. effect]
In the present embodiment, the range of the color mixture region generated by the foreign material 3 is limited to the narrow first space SA close to the foreign material 3, so that the effect of suppressing the spread of the color mixture range can be obtained, and the display panel 100 emits light. Color defects can be reduced.

Further, it is determined whether or not to repair the bank 14 based on the degree of overlap of the foreign material 3 on the bank 14 with respect to the detected foreign material 3, and only the foreign material 3 satisfying the standard is repaired. Do. Thereby, it is possible to reduce the number of dark spots generated due to the repair of the bank.
[9. Modified example]
In the embodiment, the bank molded body 14a is pre-fired before the foreign matter 3 is detected in step S5. However, the bank molded body 14a may be pre-fired after the foreign matter 3 is detected, and the same effect is obtained. .

In the embodiment, the bank molded body 14a is formed by a photolithography method, but the method for forming the bank molded body 14a is not limited to the photolithography method.
For example, the bank molded body 14a can be formed by applying a bank material containing a thermosetting resin onto the substrate in a bank shape by an imprint method.
Also in that case, similarly to the above embodiment, the bank formed body 14a is pre-fired, the foreign matter 3 is detected, and the repair material is applied, so that the repaired bank 14 is formed and the same effect is obtained. Can do.

In the embodiment, the top emission type organic EL panel has been described as an example, but the present invention can also be applied to a bottom emission type organic EL panel.
In the embodiment, foreign objects under the bank are detected by executing foreign object detection before forming the bank, and foreign objects on the bank are detected by executing foreign object detection after forming the bank. The method of detection by distinguishing the foreign matter above and the foreign matter below the bank is not limited to this. For example, the repair device 200 includes a focus lens that changes the focus position of the image sensor 211 based on an instruction from the controller 230, detects a foreign object on the bank by capturing an image with the focus position on the bank, A foreign object under the bank may be detected by imaging with the focus position under the bank.

  The organic EL display panel and the organic EL display device according to the present disclosure can be widely used in various electronic devices including devices such as a television set, a personal computer, and a mobile phone, or other display panels.

DESCRIPTION OF SYMBOLS 1 Organic EL display device 3 Foreign material 5 Weir 5a Weir molded body 10 Organic EL element 11 Base substrate 12 Pixel electrode 13 Hole injection layer 14 Bank 14a Bank molded body 15 Organic light emitting layer 15a Ink layer 16 Electron transport layer 17 Common electrode 18 Sealing Layer 20 Concave space (groove space)
100 Display panel

Claims (3)

A method of manufacturing an organic EL display panel in which a substrate is partitioned by a plurality of banks, and a light emitting layer is formed in each partition,
Forming a bank extending in a column direction on the substrate;
Detecting foreign matter existing in a state of overlapping with the bank when the substrate is viewed in plan;
Determining whether or not repair is necessary for the bank around the detected foreign matter;
Repairing the bank according to a determination result,
In the determining step,
When the bank exists below the detected foreign matter, it is determined that repair is necessary when the ratio of the width of the foreign matter to the width of the bank is greater than α1,
A method of manufacturing an organic EL display panel, in which, when the bank exists above the detected foreign matter, it is determined that repair is required when the ratio of the width of the foreign matter to the width of the bank is greater than α2 that is greater than α1. The method of manufacturing an organic EL display panel according to claim 1, wherein α1 is 0 and α2 is 0.5. In the step of detecting the foreign matter, the foreign matter existing below the bank is detected by performing foreign matter detection before the step of forming the bank, and the foreign matter detection is performed after the step of forming the bank. The method for manufacturing an organic EL display panel according to claim 1, wherein foreign matter existing above the bank is detected.

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