JP2005284276A - Method of manufacturing display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a display device whose display performance is enhanced and with which high manufacturing yield is obtained. <P>SOLUTION: The method of manufacturing the display device includes a step of forming an insulation layer on a substrate 120a, a step of coating a first mask material 203 on an area associated with a first color pixel on the insulating layer 201, a step of coating a second mask material 203 on an area associated with a second color pixel on the insulating layer 201 and a step of patterning the insulating layer 201 using the first mask material and the second mask material and forming a first diffraction grating and a second diffraction grating that have different grating pitches. The first mask material and the second mask material are coated by a selective coating method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a display device, and more particularly to a method for manufacturing a display device including a plurality of self-luminous elements.

  In recent years, organic electroluminescence (EL) display devices have attracted attention as flat display devices. Since this organic EL display device is a self-luminous element, it has a wide viewing angle, can be thinned without requiring a backlight, has low power consumption, and has a high response speed. ing.

  Because of these characteristics, organic EL display devices are attracting attention as potential candidates for next-generation flat display devices that can replace liquid crystal display devices. Such an organic EL display device includes an array substrate configured by arranging organic EL elements having an organic active layer containing an organic compound having a light emitting function between an anode and a cathode in a matrix. .

  As a typical method for realizing an organic EL display device capable of color display, there is a method of arranging color pixels that emit light in three colors of red (R), green (G), and blue (B). However, there is a problem that only about 20% of the light generated in the organic EL element can be extracted outside. For this reason, if sufficient luminance is to be obtained, it is necessary to supply a large current to the organic EL element, which is not preferable.

Therefore, a technique for arranging a diffraction grating has been proposed in order to improve the extraction efficiency of light generated in the organic EL element (see, for example, Patent Document 1).
JP 2003-163075 A

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for manufacturing a display device that can improve display performance and has a good manufacturing yield.

A manufacturing method of a display device according to the first aspect of the present invention includes:
A first color pixel and a second color pixel arranged on a substrate and emitting light of different wavelengths;
A first diffraction grating provided corresponding to the first color pixel;
A second diffraction grating provided corresponding to the second color pixel and having a grating pitch different from that of the first diffraction grating, comprising:
Forming an insulating layer on the substrate;
Applying a first mask material to a region corresponding to the first color pixel on the insulating layer;
Applying a second mask material to a region corresponding to the second color pixel on the insulating layer;
Patterning the insulating layer using the first mask material and the second mask material to form the first diffraction grating and the second diffraction grating, respectively.
The first mask material and the second mask material are applied by a selective application method.

A manufacturing method of a display device according to the second aspect of the present invention includes:
A first color pixel and a second color pixel arranged on a substrate and emitting light of different wavelengths;
A first diffraction grating provided corresponding to the first color pixel;
A second diffraction grating provided corresponding to the second color pixel and having a grating pitch different from that of the first diffraction grating, comprising:
Forming an insulating layer on the substrate;
Selectively applying a first polymer to a region corresponding to the first color pixel on the insulating layer;
Selectively applying a second polymer to a region corresponding to the second color pixel on the insulating layer;
Phase-separating the first polymer and the second polymer to form the first diffraction grating and the second diffraction grating, respectively;
It is provided with.

  According to the present invention, it is possible to improve the display performance and provide a method for manufacturing a display device with a good manufacturing yield.

  A display device manufacturing method according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a self-luminous display device such as an organic EL (electroluminescence) display device will be described as an example of the display device.

  As shown in FIG. 1, the organic EL display device includes an array substrate 100 having a display area 102 for displaying an image, and a sealing body 200 for sealing at least the display area 102 of the array substrate 100. . The display area 102 includes a plurality of pixels PX (R, G, B) arranged in a matrix.

  Each pixel PX (R, G, B) is supplied via a pixel switch 10 and a pixel switch 10 having a function of electrically separating an on-pixel and an off-pixel and holding a video signal to the on-pixel. The driving transistor 20 supplies a desired driving current to the display element based on the video signal, and the storage capacitor element 30 holds the gate-source potential of the driving transistor 20 for a predetermined period. The pixel switch 10 and the driving transistor 20 are constituted by, for example, thin film transistors, and here, polysilicon is used for a semiconductor layer.

  Each pixel PX (R, G, B) includes an organic EL element 40 (R, G, B) as a display element. That is, the red pixel PXR includes an organic EL element 40R that emits light corresponding to the red wavelength. The green pixel PXG includes an organic EL element 40G that emits light corresponding to the green wavelength. The blue pixel PXB includes an organic EL element 40B that emits light corresponding to the blue wavelength.

  The various organic EL elements 40 (R, G, B) have basically the same configuration. For example, as shown in FIG. 2, the first electrode 60 and the first electrode 60 are formed in an independent island shape on each pixel PX. A second electrode 66 that is disposed opposite to the pixel PX and formed in common to all the pixels PX, and an organic active layer 64 that functions as a photoactive layer held between the first electrode 60 and the second electrode 66, Consists of.

  Further, the array substrate 100 has a plurality of scanning lines Ym (m = 1, 2,...) Arranged along the row direction of the pixels PX (that is, the Y direction in FIG. 1) and a direction substantially orthogonal to the scanning lines Ym. A plurality of signal lines Xn (n = 1, 2,...) Arranged along (that is, the X direction in FIG. 1) and a power supply line P for supplying power to the first electrode 60 of the organic EL element 40. And. Further, the array substrate 100 includes a scanning line driving circuit 107 that supplies a scanning signal to each scanning line Ym and a signal line driving that supplies a video signal to each signal line Xn in a peripheral area 104 along the outer periphery of the display area 102. Circuit 108.

  All the scanning lines Ym are connected to the scanning line driving circuit 107. All signal lines Xn are connected to the signal line driving circuit 108. Here, the pixel switch 10 is disposed in the vicinity of the intersection between the scanning line Ym and the signal line Xn. The gate electrode of the pixel switch 10 is connected to the scanning line Ym, the source electrode is connected to the signal line Xn, and the drain electrode is connected to one end of the storage capacitor 30 and the gate electrode 20G of the driving transistor 20.

  The drive transistor 20 is connected in series with the organic EL element 40. The source electrode 20S of the drive transistor 20 is connected to the other end of the storage capacitor element 30 and the power supply line P, and the drain electrode 20D is connected to the first electrode 60 of the organic EL element 40.

  The power supply line P is connected to a first electrode power line (not shown) arranged around the display area 102. The second electrode 66 of the organic EL element 40 is disposed around the display area 102 and is connected to a second electrode power supply line (not shown) that supplies a common potential, here, a ground potential.

  As shown in FIG. 2, the array substrate 100 includes an organic EL element 40 disposed on the wiring substrate 120. Note that the wiring substrate 120 is formed on an insulating support substrate 101 such as a glass substrate or a plastic sheet on a pixel switch 10, a driving transistor 20, a storage capacitor element 30, a scanning line driving circuit 107, a signal line driving circuit 108, and various wirings ( Scanning line, signal line, power supply line, etc.), a diffraction grating described later, and the like.

  The first electrode 60 constituting the organic EL element 40 is disposed on the wiring board 120. Here, the first electrode 60 is formed of a light-transmissive conductive member such as ITO (indium tin oxide) or IZO (indium zinc oxide), and functions as an anode.

  The organic active layer 64 includes at least a light emitting layer and is made of an organic material. The organic active layer 64 can include layers other than the light emitting layer. For example, the organic active layer 64 may be formed of a multilayer stack including a hole buffer layer and an electron buffer layer that are formed in common for all color pixels, and an organic light emitting layer formed in each color pixel. In addition, the organic active layer 64 may be composed of two layers or a single layer in which various layers including the light emitting layer are functionally combined. The hole buffer layer includes a hole injection layer, a hole transport layer, and the like, and is disposed between the anode and the organic light emitting layer, and is formed of a thin film such as an aromatic amine derivative, a polythiophene derivative, or a polyaniline derivative. The light-emitting layer is formed of an organic compound having a light-emitting function that emits red, green, or blue light. For example, when a polymer-based light emitting material is used, the light emitting layer is formed of a thin film such as PPV (polyparaphenylene vinylene), a polyfluorene derivative, or a precursor thereof. In the organic active layer 64, the light emitting layer may be an organic material, and layers other than the light emitting layer may be an inorganic material or an organic material.

The electron buffer layer includes an electron injection layer, an electron transport layer, and the like, and is disposed between the cathode and the organic light emitting layer, and is formed of a thin film such as LiF (lithium fluoride) or Alq ₃ .

  The second electrode 66 is disposed on the organic active layer 64 in common with each organic EL element 40. The second electrode 66 is formed of a metal film having an electron injection function such as Ca (calcium), Al (aluminum), Ba (barium), Ag (silver), Yb (ytterbium), and functions as a cathode. The second electrode 66 may have a two-layer structure in which the surface of a metal film functioning as a cathode is covered with a cover metal. The cover metal is made of aluminum, for example.

  Further, the array substrate 100 includes a partition wall 70 that separates the pixels RX (R, G, B) in the display area 102. The partition walls 70 are arranged in a lattice shape or a stripe shape along the periphery of the first electrode 60.

  By the way, since the organic EL element 40 is a self-luminous element, the emission direction of EL light emission extends in all directions. As a display device for observing from a specific direction, in order to efficiently extract EL light emission, a technique for taking out EL light emission that does not reach the observation direction by using reflection or refraction is indispensable.

  Therefore, an unevenness, that is, a diffraction grating having a certain degree of regularity is arranged between the observation position and the organic active layer 64, and EL light emission outside the observation direction is refracted in the observation direction at a certain frequency for effective use. There is a way. However, the diffraction grating can be easily formed on a small substrate, but is difficult to manufacture on a large substrate. In addition, in an organic EL display device capable of color display, the diffraction angle is different corresponding to each wavelength of red (R), green (G), and blue (B). Needs to be set.

  Therefore, in this embodiment, EL emitted from each organic EL element 40 (R, G, B) for three types of color pixels PX (R, G, B) that respectively emit red, green, and blue. By disposing a diffraction grating having an optimum grating pitch corresponding to the emission wavelength, the display performance can be remarkably improved.

That is, as illustrated in FIG. 2, the wiring substrate 120 includes a first insulating layer 110 disposed on the support substrate 101, and a diffraction grating disposed between the first insulating layer 110 and the organic EL element 40. 115. In this embodiment, the first insulating layer 110 includes an undercoat layer 111, a gate insulating film 112, an interlayer insulating film 113, and a planarizing layer 114. The undercoat layer 111 is disposed on the support substrate 101 and is formed of a silicon nitride film (SiN) or the like. The gate insulating film 112 is disposed on the undercoat layer 111 and is formed of a silicon oxide film (SiO ₂ ) that covers the semiconductor layer 21 and the like of the driving transistor 20. The interlayer insulating film 113 is disposed on the gate insulating film 112 and is formed of a silicon oxide film (SiO ₂ ) that covers the gate electrode 20G of the driving transistor 20 and the like. The planarization layer 114 is a hard resin coat (HRC) layer disposed on the interlayer insulating film 113.

  The diffraction grating 115 can be formed by patterning the second insulating layer 201 disposed on the first insulating layer 110. As a matter of course, the second insulating layer 201 is made of a material having a light transmission property that transmits the EL light emitted from the organic EL element 40, and is made of, for example, a silicon nitride film. The diffraction grating 115 has irregularities with an optimum grating pitch P for each color pixel on the surface (the surface facing the organic EL element). Here, the lattice pitch P corresponds to the center-to-center distance of the closest convex portion 201A. The surface of the diffraction grating 115, that is, the uneven surface, is flattened by the flattening layer 116.

  The planarizing layer 116 is formed of a material having a refractive index different from that of the second insulating layer 201 and having a light transmission property that transmits EL light emitted from the organic EL element 40. Further, the planarization layer 116 is desirably an organic insulating film having a glass transition point at 90 ° C. to 120 ° C. In this embodiment, the planarization layer 116 is an HRC layer. For example, the refractive index of the diffraction grating 115 formed of a silicon nitride film is 2.2, whereas the refractive index of the HRC layer is 1.5.

  The grating pitch P of the diffraction grating 115 is desirably set larger as the color pixel emits light having a long wavelength. For example, the grating pitch of the diffraction grating formed on the red pixel PXR is 0.22 to 1.15 μm, the grating pitch of the diffraction grating formed on the green pixel PXG is 0.18 to 0.95 μm, and the blue pixel The grating pitch of the diffraction grating formed on PXB is 0.16 to 0.85 μm.

  As described above, in the diffraction grating 115 having a different grating pitch for each color pixel, after the second insulating layer 201 is formed, a phase separation polymer is applied onto the second insulating layer 201 by an ink jet method, and this phase By using the separation polymer as a mask material, it can be formed all at once by patterning once.

  That is, the phase-separated polymer can form a part having high etching resistance and a part having low etching resistance uniformly in a plane by applying heat treatment. Moreover, the phase separation interval (pitch of the portion having high etching resistance) can be easily changed by changing the polymer type and the mixing ratio. That is, it is possible to prepare phase separation polymers having different pitches selectively for each color pixel. As the phase separation polymer, for example, materials described in “Jpn. J. Appl. Phys. Vol. 41 (2002) pp. 6112-6118, Part 1, No. 10, October 2002” can be employed.

  In other words, three types of polymers are prepared so as to have a pitch corresponding to each wavelength of red (R), green (G), and blue (B) when the phases are separated, and each is applied by an ink jet method, and heat treatment is performed. By applying the above, it is possible to form a mask that is phase-separated at a predetermined pitch according to the polymer type. By patterning through this mask, irregularities can be easily formed anywhere with a pitch corresponding to each wavelength.

  Here, an inkjet type coating apparatus for coating a mask material made of a polymer will be described. For example, as illustrated in FIG. 3, the coating apparatus 1130 includes a stage 1131 on which a substrate (that is, the wiring substrate 120) as the workpiece W is placed. An inkjet head 1132 is disposed above the stage 1131. Below the stage 1131, a rail 1133 extending in the X direction and a rail 1134 extending in the Y direction are arranged so as to be substantially orthogonal to each other. The stage 1131 can be moved along the X direction on the rail 1133 by a driving mechanism (not shown). The rail 1133 is movable along the Y direction on the rail 1134 together with the stage 1131 by a driving mechanism (not shown). With such a configuration, the workpiece W placed on the stage 1131 can move relative to the inkjet head 1132 in both the X direction and the Y direction substantially orthogonal to each other.

  Next, a manufacturing process of the diffraction grating 115 will be described.

  First, as shown in FIG. 4A, a substrate 120a provided with a first insulating layer 110 is prepared. That is, by repeating processes such as formation of a metal film and an insulating film and patterning, the pixel switch 10, the driving transistor 20, the storage capacitor 30, the scanning line driving circuit 107, the signal line driving circuit 108, In addition to various wirings such as signal lines Xn, scanning lines Ym, and power supply lines P, a first insulating layer 110 including an undercoat layer 111, a gate insulating film 112, an interlayer insulating film 113, and a planarizing layer 114 is formed. Then, a substrate 120a having a total of 920,000 pixels of vertical 480 pixels and horizontal 640 × 3 (R, G, B) pixels is prepared. The wiring board 120 is formed by forming the diffraction grating 115 on the board 120a.

  Subsequently, the second insulating layer 201 is formed on one main surface on the substrate 120 a, that is, on the first insulating layer 110. Here, the silicon nitride film disposed over the planarization layer 114 is the second insulating layer 201. Note that the second insulating layer 201 and the planarization layer 114 include a contact hole that enables conduction with the drain electrode 20D of the driving transistor 20.

  Subsequently, as shown in FIG. 4B, a resist 202 is formed on the second insulating layer 201 to separate regions corresponding to the respective color pixels. The resist 202 is, for example, a positive tone resist used for normal patterning. After the resist 202 is formed on the entire surface of the second insulating layer 201, the region where the diffraction grating 115 is to be formed, that is, the blue region ArB corresponding to the blue pixel, the green region ArG corresponding to the green pixel, and Then, patterning is performed so as to remove each of the red regions ArR corresponding to the red pixels. The area Ar (R, G, B) in which the diffraction grating 115 is to be formed is formed to have a size slightly larger than the opening of each color pixel to be formed later, and the outer periphery of the region is arranged so as to include the outer periphery of the color pixel. Is done. The resist 202 serves as a separation wall that prevents mixing of a mask material to be applied next with other adjacent color pixels. The resist 202 may be formed in a grid pattern on the second insulating layer 201. In the case where the same color pixels are arranged in the row direction or the column direction, the resist 202 is provided between the color pixels. It may be formed in a stripe shape.

  Subsequently, as shown in FIG. 4C, a mask material 203 for patterning the second insulating layer 201 is applied on the second insulating layer 201 by an inkjet method. That is, the substrate 120 a provided with the resist 202 is placed on the stage 1131 of the coating apparatus 1130. Then, a blue region mask material 203B is applied to the blue region ArB, a green region mask material 203G is applied to the green region ArG, and the red region ArR is applied to the red region ArR via the inkjet head 1132. Mask material 203R is applied.

  As described above, these mask materials 203 (R, G, B) are phase-separated polymers, and when they are phase-separated by heat treatment, the intervals between portions having high etching resistance, that is, mask pitches are different from each other. It has been adjusted. That is, the mask material 203B is adjusted so that the mask pitch when phase-separated is 0.16 to 0.85 μm. The mask material 203G is adjusted so that the mask pitch is 0.18 to 0.95 μm. The mask material 203R is adjusted so that the mask pitch is 0.22 to 1.15 μm.

  Subsequently, the substrate 120a coated with the mask material 203 (R, G, B) is subjected to heat treatment. That is, by annealing the substrate 120a coated with the mask material 203 at 180 ° C. for 8 hours, the mask materials 203 (R, G, B) are phase-separated at a predetermined mask pitch as shown in FIG. 4D. That is, each mask material 203 (R, G, B) is phase-separated into a portion P1 having high etching resistance and a portion P2 having low etching resistance. At this time, the annealing time may be adjusted to the mask material that is most difficult to separate.

Subsequently, the diffraction grating 115 is formed. First, as shown in FIG. 4E, each mask material 203 (R, G, B) is etched. That is, the region of the phase separation polymer that is easily dry-etched by O ₂ ashing (the portion P2 having low etching resistance) is removed. At this time, it is desirable that the selection ratio between the resist 202 and the portion P2 of the mask material (phase separation polymer) 203 that is easily etched is resist: mask material = 1: 1.7. As a result, only the portion P <b> 1 with high etching resistance of the mask material 203 remains on the second insulating film 201.

Thereafter, as shown in FIG. 4F, the second insulating layer 201 is etched. That is, the second insulating layer 201 is dry-etched with a CF ₄ —O ₂ -based mixed gas through the mask material 203. Thereby, the convex part 201A (or concave part 201B) having a height (or depth) of about 70 to 100 nm is formed in the second insulating layer 201. Thereafter, both the resist 202 and the mask material 203 remaining on the surface of the second insulating layer 201 are removed by wet etching.

  Thereafter, as shown in FIG. 4G, the recess 201B is filled with a material having a refractive index different from that of the second insulating layer 201, and a planarizing layer 116 for planarizing the surface of the second insulating layer 201 is formed. That is, a photosensitive organic insulating film having a glass transition point of about 90 to 120 ° C. is formed on the second insulating layer 201 so that the film thickness at the flat portion is about 0.5 to 0.9 μm. Thereafter, a contact hole that enables conduction with the drain electrode 20D of the driving transistor 20 is formed, and heat treatment is performed at around 100 ° C. for 30 minutes. The organic insulating film is increased in fluidity by being maintained at a constant temperature near the glass transition point during the heat treatment. As a result, the organic insulating film fills the concave portion 201B on the surface of the second insulating layer 201 and is disposed on the convex portion 201A of the second insulating layer 201, and further planarizes the surface of the organic insulating film itself. . In this way, the planarization layer 116 is formed. Through these steps, diffraction gratings 115 having different grating pitches are formed in the blue region ArB, the green region ArG, and the red region ArR, respectively. That is, the diffraction grating 115 includes a diffraction grating 115B for the blue region, a diffraction grating 115G for the green region, and a diffraction grating 115R for the red region. The diffraction grating 115B is formed to have the first grating pitch through the mask material 203B for the blue region. The diffraction grating 115G is formed to have a second grating pitch different from the first pitch through the mask material 203G for the green region. The diffraction grating 115R is formed to have a third grating pitch different from the first pitch and the second pitch through the mask material 203R for the red region. At this time, the diffraction grating 115 is entirely planarized with a thickness of about 30 nm from the upper end of the convex portion 201A of the second insulating layer 201.

  Subsequently, a first electrode 60 made of ITO is formed on each pixel of the wiring board 120 provided with the diffraction grating 115. The first electrode 60 may be generally formed by a photolithography process or may be formed by a mask sputtering method.

  Subsequently, the partition wall 70 is formed. That is, the partition wall 70 is formed by patterning with a general photolithography process using a photosensitive resin material such as an acrylic type positive tone resist.

  Subsequently, an organic active layer 64 including a hole buffer layer and the like in addition to the organic light emitting layer is formed in each pixel. That is, a 2.0 wt% weight solution of a high-molecular light-emitting polymer material that forms a hole buffer layer, an organic light-emitting layer, or the like is sprayed into the pixels partitioned by the partition walls 70 and applied onto the first electrode 60. . The solution is applied using a piezo-type ink jet nozzle under the condition that the supply amount of the light emitting polymer material is 0.05 ml / min.

  And the solvent contained in a solution is removed by performing the drying process for 15 second under high temperature of 100 degreeC. The organic active layer 64 of each pixel formed in this way is formed to a uniform film thickness after removing the solvent, and is formed to a film thickness of about 1500 angstroms here. For this reason, the second electrode 66 and the first electrode 60 to be formed later are reliably electrically insulated, and the occurrence of a short circuit can be prevented.

Subsequently, the second electrode 66 is formed on the organic active layer 64. That is, barium (Ba) is vapor-deposited as a metal film functioning as a cathode to a thickness of 600 angstroms at a vacuum degree of 10 ⁻⁷ Pa, and subsequently aluminum (Al) as a metal film functioning as a cover metal is 1500 to 3000. Vapor deposition with angstrom thickness. Thereby, the organic EL element 40 is formed.

  Subsequently, in order to seal the display area 102 on the array substrate 100, an ultraviolet curable sealing material 400 is applied along the outer periphery of the sealing body 200, and in an inert gas atmosphere such as nitrogen gas or argon gas. , The array substrate 100 and the sealing body 200 are bonded together. Thereby, the organic EL element 40 is enclosed in the sealed space of an inert gas atmosphere. Thereafter, the sealing material 400 is cured by irradiating with ultraviolet rays.

  The bottom-emission color display type active matrix organic EL display device formed in this way compares the luminance with the same driving current as that of the conventional method without a diffraction grating, and can obtain a luminance nearly four times higher. And good display performance was achieved. In addition, it is not necessary to supply a large current to the element in order to improve luminance, and deterioration of the element can be suppressed, so that sufficient performance as a product can be maintained over a long period.

  In addition, since the inkjet method is used to form the mask material 203 (R, G, B) and the organic active layer 64 for forming the diffraction grating 115, the material use efficiency is as high as about 80%. It was confirmed that everything except those remaining in the supply system was effectively used for film formation. Thereby, a manufacturing yield can be improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  For example, the structure of the organic EL element applicable in the present invention may be anything as long as it exhibits its function. That is, a device in which an organic active layer is formed by a vapor deposition patterning method using a low molecular material or a device in which an organic active layer is formed by an ink jet method using a high molecular material may be used.

  In the application of the mask material, the ink jet method is adopted as the selective application method, but other selective application methods may be used.

  The diffraction grating 115 includes a second insulating layer 201 having a concavo-convex surface with a predetermined pitch on the substrate 120a, and a planarizing layer 116 having a refractive index different from that of the second insulating layer 201 and overlaid on the concavo-convex surface. However, the present invention is not limited to this example. For example, the diffraction grating 115 may be formed of a phase separation polymer in which portions having different refractive indexes are separated at a predetermined pitch on the substrate 120a. In this case, for example, the diffraction grating can be easily formed by phase-separating the phase-separated polymer applied in the above-described embodiment.

  Further, even if a light scattering layer is formed in place of the diffraction grating, the display performance is good and the production yield is good. For example, using a selective coating method such as an ink jet method, a liquid mixture of fine particles for adjusting the light extraction function and a resin to which the fine particles are fixed is changed to a phase separation polymer and applied. As a result, it is possible to easily arrange the light scattering layer whose conditions are optimally adjusted for each color. For example, it is possible to apply a resin in which fine particles having different particle diameters, particle shapes, and particle materials are mixed for each color. And compared with the case where a whole surface coating method such as a spin coating method is used, unevenness caused by a difference in centrifugal force applied during spinning can be suppressed. Furthermore, the patterning process in which the fine particles become an obstacle and the processing accuracy becomes a problem becomes unnecessary, and the manufacturing yield can be further improved.

FIG. 1 is a diagram schematically showing a configuration of an organic EL display device according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view schematically showing the structure of one pixel of the organic EL display device shown in FIG. FIG. 3 is a diagram schematically showing the structure of an ink jet apparatus for applying a mask material. FIG. 4A is a diagram for explaining a process for preparing a wiring board having a first insulating layer and a process for forming a second insulating layer on the first insulating layer in a manufacturing process for forming an organic EL display device. FIG. FIG. 4B is a diagram for explaining a process of forming a separation wall on the second insulating layer in the manufacturing process for forming the organic EL display device. FIG. 4C is a diagram for explaining a process of applying a mask material on the second insulating layer in the manufacturing process for forming the organic EL display device. FIG. 4D is a diagram for explaining a process of phase-separating the mask material in the manufacturing process for forming the organic EL display device. FIG. 4E is a diagram for explaining a process of forming a diffraction grating in a manufacturing process for forming an organic EL display device. FIG. 4F is a diagram for explaining a process of forming a diffraction grating in a manufacturing process for forming an organic EL display device. FIG. 4G is a diagram for explaining a process of forming a diffraction grating in a manufacturing process for forming an organic EL display device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Organic EL display apparatus, 10 ... Pixel switch, 20 ... Drive transistor, 30 ... Storage capacitor element, 40 ... Organic EL element, 60 ... 1st electrode, 64 ... Organic active layer, 66 ... 2nd electrode, 70 ... Partition , 100 ... Array substrate, 110 ... First insulating layer, 115 ... Diffraction grating, 200 ... Sealed body, 201 ... Second insulating layer, 203 ... Mask material, PX ... Pixel, 1130 ... Inkjet device, 1132 ... Inkjet head

Claims (8)

A first color pixel and a second color pixel arranged on a substrate and emitting light of different wavelengths;
A first diffraction grating provided corresponding to the first color pixel;
A second diffraction grating provided corresponding to the second color pixel and having a grating pitch different from that of the first diffraction grating, comprising:
Forming an insulating layer on the substrate;
Applying a first mask material to a region corresponding to the first color pixel on the insulating layer;
Applying a second mask material to a region corresponding to the second color pixel on the insulating layer;
Patterning the insulating layer using the first mask material and the second mask material to form the first diffraction grating and the second diffraction grating, respectively.
The method for manufacturing a display device, wherein the first mask material and the second mask material are applied by a selective application method.   The method for manufacturing a display device according to claim 1, wherein the first mask material and the second mask material are phase separation polymers.   A separation wall that separates a region corresponding to the first color pixel and a region corresponding to the second color pixel on the insulating layer before the step of applying the first mask material and the second mask material. The method for manufacturing a display device according to claim 1, further comprising:   The grating pitch of the diffraction grating formed in the first color pixel is smaller than the grating pitch of the diffraction grating formed in the second color pixel that emits light having a longer wavelength than the first color pixel. The manufacturing method of the display apparatus of Claim 1.   2. The method according to claim 1, wherein the step of forming the first diffraction grating and the second diffraction grating includes a step of planarizing a surface of the patterned insulating layer with a material having optical transparency. Manufacturing method of display device.   The method for manufacturing a display device according to claim 5, wherein the material for flattening the diffraction grating is an organic insulating film having a glass transition point at 90 ° C. to 120 ° C. 6.   The color pixel includes a first electrode having light transmissivity formed in an independent island shape on the diffraction grating, a second electrode disposed to face the first electrode, the first electrode, and the first electrode. The method for manufacturing a display device according to claim 1, further comprising a photoactive layer held between the two electrodes. A first color pixel and a second color pixel arranged on a substrate and emitting light of different wavelengths;
A first diffraction grating provided corresponding to the first color pixel;
A second diffraction grating provided corresponding to the second color pixel and having a grating pitch different from that of the first diffraction grating, comprising:
Forming an insulating layer on the substrate;
Selectively applying a first polymer to a region corresponding to the first color pixel on the insulating layer;
Selectively applying a second polymer to a region corresponding to the second color pixel on the insulating layer;
Phase-separating the first polymer and the second polymer to form the first diffraction grating and the second diffraction grating, respectively;
A method for manufacturing a display device, comprising:

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