JP4544645B2 - Manufacturing method of organic EL display device - Google Patents

Description

  The present invention relates to an organic electroluminescence (EL) display technique.

  Flat display devices represented by liquid crystal display devices are growing in demand rapidly, taking advantage of the features such as thinness, light weight, and low power consumption compared with CRT displays. It has come to be used for various displays such as large televisions. In recent years, an organic electroluminescence (EL) element that is self-luminous, has a high-speed response, a wide viewing angle, and a high contrast as compared with a liquid crystal display device, and can be further reduced in thickness and weight. The display device used has been actively developed.

  This organic EL device injects holes from a hole injection electrode (anode), injects electrons from an electron injection electrode (cathode), and recombines holes and electrons in a light emitting layer to obtain light emission. It is. In order to obtain a full-color display, it is necessary to configure pixels that emit light in red (R), green (G), and blue (B), respectively, and light emission of organic EL elements that configure each pixel of red, green, and blue It is necessary to coat the layers with light emitting materials that emit light having different emission spectra such as red, green, and blue. As a method for separately coating such a light emitting material, in the case of a low molecular organic EL material formed by vacuum deposition, there is a method of performing mask deposition independently using a metallic fine mask opened for each color pixel. is there.

  However, in this mask vapor deposition method using a metal fine mask, high definition (resolution) is required as a display device, and when pixels become finer, it becomes difficult to obtain sufficient accuracy, and each color A so-called poor color mixture, in which luminescent materials are mixed, frequently occurs, and normal display cannot be obtained. This is different from a so-called photomask used for photolithography, in the case of a metal mask, in addition to the low initial processing accuracy, the size and position of the opening due to thermal expansion and distortion caused by the radiation heat of the evaporation source. Can be cited as a major change.

In addition, the mask vapor deposition method using a metal mask is further reduced in accuracy as the size of the mask is increased, and the size of the display device is limited.
JP 2003-157773 A

  An object of the present invention is to provide a method for manufacturing an organic EL display device capable of displaying a high-definition multicolor image and improving production efficiency.

According to the method of manufacturing an organic EL display device according to an aspect of the present invention,
Comprising: an insulating substrate; and first to third organic EL elements arranged on the insulating substrate and having different emission colors.
Each of the first to third organic EL elements includes a first electrode, a second electrode facing the first electrode, and an organic material layer interposed between the first electrode and the second electrode. Including
The organic material layer includes a laminate in which first to third light emitting layers having different emission colors are stacked in this order, and is a method of manufacturing an organic EL display device,
When the traveling direction of light is the Z direction and the directions orthogonal to each other in the plane orthogonal to the Z direction are the X direction and the Y direction, the light has a polarization component in the Z direction in addition to the X direction and the Y direction. It has the exposure process which exposes an organic substance layer, It is characterized by the above-mentioned.

  According to the present invention, it is possible to display a high-definition multicolor image without using a metal fine mask for pattern-forming the light emitting layer in the manufacturing process of the organic EL display device, and to improve the production efficiency. It is possible to provide a method for manufacturing an organic EL display device that can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  FIG. 1 is a plan view schematically showing an organic EL display device according to an aspect of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of a structure that can be employed in the display device of FIG. FIG. 3 is a cross-sectional view schematically showing an example of a structure that can be employed in the organic EL element included in the display device of FIG. FIG. 4 is a plan view schematically showing an example of pixel arrangement that can be employed in the display device of FIG.

  The display device of FIGS. 1 and 2 is a top emission type organic EL display device adopting an active matrix driving method. This display device includes a display panel DP, a video signal line driver XDR, and a scanning signal line driver YDR.

The display panel DP includes, for example, an insulating substrate SUB such as a glass substrate. An undercoat layer (not shown) is formed on the substrate SUB. The undercoat layer is formed, for example, by laminating a SiN _x layer and a SiO _x layer in this order on the substrate SUB.

  On the undercoat layer, for example, a semiconductor pattern made of polysilicon containing impurities is formed. A part of this semiconductor pattern is used as the semiconductor layer SC. Impurity diffusion regions used as a source and a drain are formed in the semiconductor layer SC. Further, another part of the semiconductor pattern is used as a lower electrode of a capacitor C described later. The lower electrodes are arranged corresponding to pixels PX1 to PX3 described later.

  Note that the pixels PX1 to PX3 are arranged in this order in the X direction to form a triplet. In the display area, the triplets are arranged in the X direction and the Y direction. That is, in the display area, a pixel column in which the pixels PX1 are arranged in the Y direction, a pixel column in which the pixels PX2 are arranged in the Y direction, and a pixel column in which the pixels PX3 are arranged in the Y direction are arranged in this order in the X direction. In addition, these three pixel columns are repeatedly arranged in the X direction.

  The semiconductor pattern is covered with the gate insulating film GI. The gate insulating film GI can be formed using, for example, TEOS (tetraethyl orthosilicate). Scan signal lines SL1 and SL2 are formed on the gate insulating film GI. The scanning signal lines SL1 and SL2 each extend in the X direction and are alternately arranged in the Y direction. The scanning signal lines SL1 and SL2 are formed using, for example, MoW.

  An upper electrode of the capacitor C is further disposed on the gate insulating film GI. The upper electrode is arranged corresponding to the pixels PX1 to PX3, and faces the lower electrode. The upper electrode is formed using, for example, MoW, and can be formed in the same process as the scanning signal lines SL1 and SL2.

  The scanning signal lines SL1 and SL2 intersect the semiconductor layer SC. The intersection of the scanning signal line SL1 and the semiconductor layer SC constitutes a switching transistor SWa. The intersection between the scanning signal line SL2 and the semiconductor layer SC constitutes switching transistors SWb and SWc. The lower electrode, the upper electrode, and the insulating film GI interposed therebetween constitute a capacitor C. The upper electrode includes an extension that intersects the semiconductor layer SC. A crossing portion between the extension portion and the semiconductor layer SC forms a drive transistor DR.

  In this example, the drive transistor DR and the switching transistors SWa to SWc are top-gate p-channel thin film transistors. In FIG. 2, the portion indicated by reference symbol G is the gate of the switching transistor SWa.

The gate insulating film GI, the scanning signal lines SL1 and SL2, and the upper electrode are covered with an interlayer insulating film II. The interlayer insulating film II is formed using, for example, SiO _x deposited by a plasma CVD (chemical vapor deposition) method.

  A video signal line DL and a power supply line PSL are formed on the interlayer insulating film II. Each of the video signal lines DL extends in the Y direction and is arranged in the X direction. For example, each of the power supply lines PSL extends in the Y direction and is arranged in the X direction. A source electrode SE and a drain electrode DE are formed on the interlayer insulating film II. The source electrode SE and the drain electrode DE connect elements in each of the pixels PX1 to PX3. The source electrode SE and the drain electrode DE are connected to an impurity diffusion region provided in the semiconductor layer SC by a contact hole opened in the interlayer insulating film II.

  The video signal line DL, the power supply line PSL, the source electrode SE, and the drain electrode DE have, for example, a three-layer structure of Mo / Al / Mo. These can be formed in the same process. The video signal line DL, the power supply line PSL, the source electrode SE, and the drain electrode DE are covered with a passivation film PS. The passivation film PS is formed using, for example, SiNx.

  On the passivation film PS, pixel electrodes (for example, corresponding to the first electrode) PE are arranged corresponding to the pixels PX1 to PX3. Each pixel electrode PE is connected to the drain electrode DE through a contact hole provided in the passivation film PS. This drain electrode is connected to the drain of the switching transistor SWa. The pixel electrode PE is an anode in this example. As a material of the pixel electrode PE, for example, a light-transmitting conductive material such as ITO (indium tin oxide) can be used.

  A partition insulating layer PI is further formed on the passivation film PS. In the partition insulating layer PI, a through hole is provided at a position corresponding to the pixel electrode PE, or a slit is provided at a position corresponding to a column formed by the pixel electrode PE. Here, as an example, the partition insulating layer PI is provided with a through hole at a position corresponding to the pixel electrode PE. The partition insulating layer PI is, for example, an organic insulating layer. The partition insulating layer PI can be formed using, for example, a photolithography technique.

  An organic layer ORG is formed on each pixel electrode PE. As shown in FIG. 2, the organic layer ORG is typically a continuous film extending over the display area including all the pixels PX1 to PX3. That is, the organic layer ORG covers the pixel electrode PE and the partition insulating layer PI.

  The partition insulating layer PI and the organic layer ORG are covered with a counter electrode (for example, corresponding to a second electrode) CE. In this example, the counter electrode CE is a cathode and a common electrode shared by the pixels PX1 to PX3. The counter electrode CE is electrically connected to an electrode wiring (not shown) formed on the same layer as the video signal line DL through, for example, a contact hole provided in the passivation film PS and the partition insulating layer PI. It is connected.

  The pixel electrode PE, the organic layer ORG, and the counter electrode CE form an organic EL element OLED arranged in correspondence with the pixel electrode PE. In FIG. 4, reference numerals EA1 to EA3 indicate the light emitting portions of the organic EL elements OLED included in the pixels PX1 to PX3, respectively. Each of the light emitting units EA1 to EA3 is a right-angled quadrilateral extending in the Y direction. In the structure of FIG. 4, the areas of the light emitting portions EA1 to EA3 are substantially equal to each other.

  As shown in FIG. 1, each of the pixels PX1 to PX3 includes a drive transistor DR, switching transistors SWa to SWc, an organic EL element OLED, and a capacitor C. As described above, in this example, the drive transistor DR and the switching transistors SWa to SWc are p-channel thin film transistors.

  The drive transistor DR, the switching transistor SWa, and the organic EL element OLED are connected in series in this order between the first power supply terminal ND1 and the second power supply terminal ND2. In this example, the power supply terminal ND1 is a high potential power supply terminal, and the power supply terminal ND2 is a low potential power supply terminal.

  The gate of the switching transistor SWa is connected to the scanning signal line SL1. The switching transistor SWb is connected between the video signal line DL and the drain of the drive transistor DR, and its gate is connected to the scanning signal line SL2. The switching transistor SWc is connected between the drain and gate of the driving transistor DR, and the gate is connected to the scanning signal line SL2. The capacitor C is connected between the gate of the driving transistor DR and the constant potential terminal ND1 '. In this example, the constant potential terminal ND1 'is connected to the power supply terminal ND1.

  The video signal line driver XDR and the scanning signal line driver YDR are disposed on the substrate SUB. That is, the video signal line driver XDR and the scanning signal line driver YDR are mounted on a COG (chip on glass). Note that the video signal line driver XDR and the scanning signal line driver YDR may be mounted with TCP (tape carrier package) instead of being mounted with COG. Alternatively, the video signal line driver XDR and the scanning signal line driver YDR may be formed directly on the substrate SUB.

  A video signal line DL is connected to the video signal line driver XDR. In this example, a power supply line PSL is further connected to the video signal line driver XDR. The video signal line driver XDR outputs a current signal as a video signal to the video signal line DL and supplies a power supply voltage to the power supply line PSL.

  Scanning signal lines SL1 and SL2 are connected to the scanning signal line driver YDR. The scanning signal line driver YDR outputs voltage signals as first and second scanning signals to the scanning signal lines SL1 and SL2, respectively.

  When an image is displayed on this organic EL display device, for example, the scanning signal line SL2 is sequentially scanned. That is, the pixels PX1 to PX3 are selected for each row. In a selection period in which a certain row is selected, a writing operation is performed on the pixels PX1 to PX3 included in the row. In the non-selection period in which the row is not selected, the display operation is performed on the pixels PX1 to PX3 included in the row.

In the selection period in which the pixels PX1 to PX3 in a certain row are selected, the scanning signal line driver YDR performs scanning (opens a non-conducting state) to open the switching transistor SWa to the scanning signal line SL1 to which the previous pixels PX1 to PX3 are connected. The signal is output as a voltage signal, and subsequently, a scanning signal that closes the switching transistors SWb and SWc (sets the conductive state) to the scanning signal line SL2 connected to the previous pixels PX1 to PX3 is output as a voltage signal. In this state, the video signal line driver XDR outputs the video signal to the video signal line DL as a current signal (write current) I _sig , and uses the gate-source voltage V _gs of the drive transistor DR as the previous video signal I. A size corresponding to _sig is set. Thereafter, the scanning signal line driver YDR outputs a scanning signal for opening the switching transistors SWb and SWc as a voltage signal to the scanning signal line SL2 to which the previous pixels PX1 to PX3 are connected. Subsequently, the previous pixels PX1 to PX3 A scanning signal for closing the switching transistor SWa is output as a voltage signal to the connected scanning signal line SL1. This ends the selection period.

In the non-selection period following the selection period, the switching transistor SWa remains closed and the switching transistors SWb and SWc remain open. In the non-selection period, a drive current _Idrv having a magnitude corresponding to the gate-source voltage _Vgs of the drive transistor DR flows through the organic EL element OLED. The organic EL element OLED emits light with a luminance corresponding to the magnitude of the drive current _Idrv . Here, I _{drv ≈I sig} , and light emission corresponding to the current signal (write current) I _sig can be obtained in each pixel.

  The above example employs a configuration in which a current signal is written as a video signal in the pixel circuit. However, a configuration in which a voltage signal is written in the pixel circuit as a video signal can also be employed. It is not limited to. In this embodiment, a p-channel thin film transistor is used. However, the use of an n-channel thin film transistor does not change the essence of the present invention.

  Further, the organic EL element OLED is sealed by bonding a sealing substrate SUB2 formed of glass with a desiccant or the like with a sealing material applied around the display area.

Examples of the present invention will be described below.
(Example)
In this example, a 3.0 type WVGA organic EL display was prepared. The pixel size is 82.5 μm × 27.5 μm, and the number of pixels is 800 × 3 × 480. Here, the pixel size indicates the size of each of the pixel PX1, the pixel PX2, and the pixel PX3. In the present embodiment, the pixel size is the same. In this embodiment, the ITO of the pixel electrode PE has a thickness of 50 nm.

  In this example, as shown in FIG. 3, the organic layer ORG was formed by laminating a red light emitting layer EML1, a green light emitting layer EML2, and a blue light emitting layer EML3. The red light emitting layer EML1, the green light emitting layer EML2, and the blue light emitting layer EML3 were each formed as a continuous film extending over the display region including all the pixels PX1 to PX3.

  Here, the red light emitting layer EML1 is formed of a mixture of the first host material HM1 and the first dopant material EM1 whose emission color is red. The first dopant material EM1 is a red light-emitting material made of a luminescent organic compound or composition having an emission center at a red wavelength. In this example, the red light emitting layer EML1 includes the first host material HM1: 9,9-bis (9-phenyl-9H-carbazol) fluorene (abbreviation: FL-2CBP), and the first dopant material EM1: 4. A 30 nm thick layer of-(dicyanomethylene) -2-methyl-6- (julolidin-4-yl-vinyl) -4H-pyran (abbreviation; DCM2) was used. The red light emitting layer EML1 was formed by a vacuum deposition method and was a continuous film extending over the display area.

The green light emitting layer EML2 is formed of a mixture of the second host material HM2 and the second dopant material EM2 having a green emission color. The second dopant material EM2 is a green light-emitting material made of a luminescent organic compound or composition having an emission center at a green wavelength. In this example, the green light emitting layer EML2 has a thickness of 30 nm made of the second host material HM2: FL-2CBP and the second dopant material EM2: tris (8-hydroxyquinolato) aluminum (abbreviation: Alq ₃ ). Layers were used. The green light-emitting layer EML2 was formed by a vacuum deposition method and was a continuous film extending over the display area.

  The blue light-emitting layer EML3 is a thin film containing a luminescent organic compound or composition whose emission color is blue. The blue light emitting layer EML3 is formed of, for example, a mixture of the third host material HM3 and the third dopant material EM3 whose emission color is blue. In this example, as the blue light-emitting layer EML3, the third host material HM3: 4,4′-bis (2,2′-diphenyl-ethen-1-yl) -diphenyl (BPVBI), and the third dopant material A 30 nm thick layer of EM3: perylene was used. The blue light emitting layer EML3 was formed by a vacuum deposition method and was a continuous film extending over the display area.

  As the first host material HM1 and the second host material HM2, 1,3,5-tris (carbazol-9-yl) benzene (abbreviation: TCP) may be used in addition to the above-described example.

  In the present embodiment, as described above, the pixel PX1, the pixel PX2, and the pixel PX3 have the organic layer ORG having the same configuration, but the emission colors of the pixel PX1, the pixel PX2, and the pixel PX3 are different from each other. It is configured as follows. In the example shown here, the organic EL element OLED included in the pixel PX1 emits red light, the organic EL element OLED included in the pixel PX2 emits green light, and the organic EL element OLED included in the pixel PX3 emits blue light.

  Note that the color of light having a wavelength in the range of 400 nm to 435 nm is purple, the color of light having a wavelength in the range of 435 nm to 480 nm is blue, the color of light having a wavelength in the range of 480 nm to 490 nm is patina, The color of light with a wavelength in the range of 490 nm to 500 nm is blue-green, the color of light with a wavelength in the range of 500 nm to 560 nm is green, the color of light with a wavelength in the range of 560 nm to 580 nm is yellow-green, The color of light having a wavelength in the range of 580 nm to 595 nm is yellow, the color of light having a wavelength in the range of 595 nm to 610 nm is orange, the color of light having a wavelength in the range of 610 nm to 750 nm is red, and the wavelength is Generally, the color of light in the range of 750 nm to 800 nm is defined as magenta. Here, the color of light having a dominant wavelength in the range of 400 nm to 490 nm is blue. Green color of light shorter than and dominant wavelength longer than 490 nm 595nm, the main wavelength is defined as the red color of the light in the range of 595nm to 800 nm.

  The production method is described below. FIG. 5 shows the process flow, and FIG. 6 shows an outline of the exposure process in FIG.

  First, a structure obtained by removing the counter electrode CE and the organic layer ORG from the display panel DP described above, that is, an array substrate is prepared in an array process.

  Next, among the layers included in the organic layer ORG, the red light emitting layer EML1 is formed on the pixel electrode PE by a vacuum deposition method. Here, the red light emitting layer EML1 is a continuous film extending over the display area, and is not a fine mask in which an opening is formed for each pixel, but mask deposition using a rough mask in which an opening corresponding to the display area is formed. Form with. This process is shown as EML1 deposition in FIG.

Next, light having a wavelength of approximately 355 to 800 nm is applied to the regions of the pixels PX2 to PX3 with an intensity of approximately 0.1 mW · mm ⁻² · nm ⁻¹ (0.001 to ¹ mW · mm ⁻² · nm ⁻¹ ). Irradiate with. At this time, the region of the pixel PX1 is prevented from being irradiated with light by using a photomask (MASK1 in FIG. 6). This process is shown as PHOTO1 exposure in FIG.

  Next, on the red light emitting layer EML1, among the layers included in the organic layer ORG, the green light emitting layer EML2 is formed as a continuous film extending over the display region by a vacuum deposition method using a rough mask. This process is shown as EML2 vapor deposition in FIG.

Next, light having a wavelength of approximately 355 to 800 nm is irradiated to the region of the pixel PX3 with an intensity of approximately 0.1 mW · mm ⁻² · nm ⁻¹ (0.001 to ¹ mW · mm ⁻² · nm ⁻¹ ). To do. At this time, the pixels PX1 and PX2 are not irradiated with light by using a photomask (MASK2 in FIG. 6). This process is shown as PHOTO2 exposure in FIG.

  Next, on the green light emitting layer EML2, among the layers included in the organic layer ORG, the blue light emitting layer EML3 is formed as a continuous film extending over the display region by a vacuum deposition method using a rough mask. This process is shown as EML3 deposition in FIG.

  Thereafter, the counter electrode CE is formed on the blue light emitting layer EML3. This process is shown as CE deposition in FIG. In this example, an aluminum layer having a thickness of 150 nm was formed as the counter electrode CE. The counter electrode CE was a continuous film extending over the display area. In this embodiment, it also serves as a reflective layer for taking out light emitted from each light emitting layer EML to the array substrate SUB side.

  Further, the organic EL element OLED is sealed, and the video signal line driver XDR and the scanning signal line driver YDR are mounted on the display panel DP. As described above, the organic EL display device of FIGS. 1 and 2 is obtained.

  By the way, when one organic EL element OLED includes a plurality of light emitting layers EML1 to EML3, there is a possibility that not only one color but also other colors emit light.

  Normally, in a configuration in which the light emitting layers EML1 to EML3 are simply stacked, the pixels PX1 to PX3 all emit light in the same color, and a full color display cannot be obtained.

  Therefore, in the present invention, pixels that irradiate light and pixels that do not irradiate light are separated by an exposure process using a photomask, and the emission color of each pixel is controlled.

  FIG. 7 is a diagram showing one principle of controlling the emission color of the pixel of the present invention.

  In the structure in which the light emitting layers EML1 to EML3 are stacked, basically, the red light emitting layer EML1 easily emits light. This is because blue and green having high energy are absorbed by the red light emitting layer EML1 having the lowest energy and converted to red, and thus red is most likely to emit light in such an RGB laminated structure. Therefore, the pixel PX1 that is not irradiated with light emits red light.

  Next, in the “PHOTO1 exposure” step after the deposition of the red light emitting layer EML1, only the first dopant material EM1 absorbs light in the pixel PX2 in which the red light emitting layer EML1 is irradiated with light having a wavelength of approximately 355 to 800 nm. As a result, decomposition, polymerization, or change in molecular structure results in no red light emission, so-called quenching. That is, among the light emitting layers EML1 to EML3 in the pixel PX2, the first dopant material EM1 in the red light emitting layer EML1 loses light emitting ability. In this state, when a stacked structure is formed, green having the second lowest energy after red easily emits light, and the pixel PX2 emits green light.

  Further, in the “PHOTO2 exposure” step after the green light emitting layer EML2 is deposited, only the second dopant material EM2 is absorbed by light absorption in the pixel PX3 in which the green light emitting layer EML2 is also irradiated with light having a wavelength of approximately 355 to 800 nm. The green light is not emitted due to decomposition or polymerization or a change in molecular structure. In this pixel PX3, since the red light emitting layer EML1 is also irradiated with light having a wavelength of approximately 355 to 800 nm in the “PHOTO1 exposure” step, the first dopant material EM1 absorbs red light due to light absorption. Is no longer emitting light.

  That is, among the light-emitting layers EML1 to EML3 in the pixel PX3, the first dopant material EM1 in the red light-emitting layer EML1 and the second dopant material EM2 in the green light-emitting layer EML2 lose the light emitting ability. In this state, when a stacked structure is formed, since there is no layer that emits light lower in energy than blue, blue easily emits light, and the pixel PX3 emits blue light.

  As described above, when the first dopant material EM1 included in the red light emitting layer EML1 and the second dopant material EM2 included in the green light emitting layer EML2 are quenched by light irradiation, the shorter the exposure time, the organic EL display. The productivity of the apparatus can be improved.

  In order to shorten the exposure time, it is possible to efficiently absorb light with respect to the dopant material.

  Radiation light from a general light source applied in the exposure process for losing the light emission ability of the dopant material is defined as the direction of light traveling in the Z direction, and the directions orthogonal to each other in a plane perpendicular to the Z direction. When the direction and the Y direction are used, only the polarization component in the X direction (X polarization component) and the polarization component in the Y direction (Y polarization component) are included. For this reason, the light traveling in the Z direction is linearly polarized light or elliptically polarized light.

  On the other hand, the film | membrane formed into a film by vapor deposition like each light emitting layer EML is an amorphous structure. For this reason, the orientation direction of the molecules contained in each light emitting layer EML is random.

  In the case where the extinction coefficient of the molecule of the dopant material that loses its luminous ability by light irradiation varies greatly depending on the polarization direction, in the amorphous structure thin film, the extinction coefficient is high for the Z-polarized component, but the X-polarized component and the Y-polarized component. There are molecules with low absorbance for the polarized component. For this reason, in the exposure apparatus using the normal light source as described above, the emitted light from the light source includes only the X-polarized component and the Y-polarized component. The exposure time in the process becomes long and the production efficiency is low.

  Therefore, in this embodiment, in the exposure step, the organic layer ORG is exposed with light having a polarization component in the Z direction (Z polarization component) in addition to the X polarization component and the Y polarization component. Thereby, when the dopant material contained in the light emitting layer EML of the organic material layer ORG contains a molecule having a high absorbance with respect to the Z-polarized component in addition to a molecule having a high absorbance with respect to the X-polarized component and the Y-polarized component. Even so, it is possible to efficiently absorb the light for each molecule, and it is possible to lose the luminous ability in a short exposure process. Therefore, production efficiency can be improved.

  Next, an exposure apparatus for realizing such exposure will be specifically described.

  FIG. 8 shows a configuration example of the polarization control element 100 that can generate the Z-polarized light component. That is, the polarization control element 100 condenses each of the linearly polarized light transmitted through the polarization modulation element 110 and the polarization modulation element 110 that generates a plurality of linear polarizations in different directions in the XY plane from the light emitted from the light source. In this configuration, the lens 120 is combined.

  The polarization modulator 110 can be configured by a liquid crystal panel having a configuration in which a liquid crystal layer is held between a pair of substrates, and is formed between a pair of substrates in a mode in which transmitted light can generate linearly polarized light in a plurality of different directions. TN (Twisted Nematic) mode for switching liquid crystal molecules using a substantially vertical longitudinal electric field, and IPS (In-Plane Switching) mode for switching liquid crystal molecules using a lateral electric field substantially parallel to the main surface of the substrate. A liquid crystal panel is preferred.

  The polarization modulation element 110 has regions with different transmission axis directions. In other words, the polarization modulation element 110 is configured such that the region for changing the polarization state of the emitted light from the light source is divided into four or more quadrants, and the phases of the light emitted from the respective quadrant regions are different. In the example illustrated in FIG. 8, the polarization modulation element 110 includes four quadrant regions 111 to 114.

  In such a polarization modulation element 110, as a method of creating regions having different transmission axis directions in a TN liquid crystal panel or IPS liquid crystal panel, “rubbing process tilt angle” and “liquid crystal alignment are controlled for each quadrant region. A method of changing the combination of “applied voltages” can be mentioned. At this time, the boundary of the quadrant region becomes non-uniform in the transmission axis direction, but the influence on the total area of the panel is small because it is small.

  When radiation light (omnidirectional light) from the light source is incident on the polarization modulation element 110 having such a configuration, X-polarized components and Y-polarized components having different phases are emitted from each quadrant region. Then, the X-polarized component and the Y-polarized component having different phases are condensed by the lens 120, so that the Z-polarized component is also generated in addition to the X-polarized component and the Y-polarized component.

  Since the phases of the light emitted from the respective quadrant regions are different, the canceling action due to the interference between the light emitted from the adjacent quadrant regions can be reduced.

  More preferably, the phases of light emitted from the first quadrant region 111, the second quadrant region 112, the third quadrant region 113, and the fourth quadrant region 114 are shifted at equal intervals. That is, the phase difference between the light emitted from the i-th quadrant region (i = 1 to N−1, N is an integer of 4 or more) of the polarization modulator 110 and the light emitted from the adjacent (i + 1) quadrant region is λ. / (4 × (N−1)) is desirable.

  In the actual exposure apparatus, as shown in FIG. 9, a liquid crystal panel configured as a polarization modulation element 110 arranged in a matrix, and an array lens 130 in which lenses 120 corresponding to the polarization modulation elements 110 are integrated, It is desirable to apply the polarization control element 100 having a configuration combining the above.

  In the lens projection type exposure apparatus as shown in FIG. 10, it is desirable that the polarization control element 100 having the above-described configuration is installed, for example, at the tip of a unit magnification projection lens. By the exposure apparatus having such a configuration, in addition to the X-polarized component and the Y-polarized component, a Z-polarized component is also generated, and by exposing the substrate, the efficiency of each molecule contained in the light emitting layer EML of the organic layer ORG is improved. It is possible to absorb light well.

  As described above, by applying the present invention, it is possible to emit a color corresponding to each RGB pixel and obtain a full color display without using a metal fine mask for separately painting RGB for each pixel.

  Further, in the case of vapor deposition using a fine mask, a useless film is likely to be formed on the mask, thereby blocking the opening of the pixel. As a result, the deposition rate of the light emitting layer EML deposited on the pixel is reduced, and more material is consumed. Accordingly, the number of times the mask is cleaned increases. On the other hand, in the present invention, only a rough mask that has a wide opening and is unlikely to form a useless film on the mask is used, so that the productivity is higher and the environmental load is less than when a fine mask is used.

  Therefore, according to the present invention, it is possible to provide a high-definition, large-sized full-color organic EL display device that is environmentally friendly and has high productivity.

  As described above, the organic EL display device of the present invention shown in FIGS. 1 and 2 was obtained.

  As a result, the pixel PX1 emitted red light, the pixel PX2 emitted green light, and the pixel PX3 emitted blue light without being mixed. The luminous efficiencies of red are 8 cd / A, (0.65, 0.35), green is 10 cd / A, (0.30, 0.60), blue is 3 cd / A, (0.14, respectively). 0.12).

The above-mentioned value is such that when the screen is observed from the front, the reference white (C) of (x, y) = (0.31, 0.315) is displayed with a luminance of 100 cd / m ² . This is a value obtained by sequentially lighting the pixels PX1 to PX3 and measuring the luminance and chromaticity (x, y) for each emission color.

  In the present embodiment, the pixels PX1, PX2, and PX3 are all the same size. However, for example, the pixels may be different in size in order to make the luminance degradation life of the emission colors of the respective pixels uniform. . Thereby, white can be made difficult to color.

  In the embodiment described above, as in the example shown in FIG. 5, the PHOTO1 exposure is performed after the EML1 deposition and the PHOTO2 exposure is performed after the EML2 deposition. However, the present invention is not limited to this example. For example, as shown in a process flow in FIG. 11, after performing EML1 deposition, EML2 deposition, and EML3 deposition, PHOTO1 exposure and PHOTO2 exposure may be performed continuously after EML3 deposition. At this time, in the PHOTO1 exposure and the PHOTO2 exposure, the main wavelength of the irradiated light is changed.

  That is, in the PHOTO1 exposure, the pixels PX2 and PX3 are irradiated with light whose main wavelength is a wavelength absorbed only by the first dopant material EM1 of the red light emitting layer EML1. Accordingly, the first dopant material EM1 is decomposed or polymerized, or the molecular structure is changed, so that the red light emitting layer EML1 in the region irradiated with light loses the light emitting ability to emit red light. When the light emitting layers EML1 to EML3 have a laminated structure as in the present invention, green having the second lowest energy after red easily emits light, and the pixel PX2 emits green light.

  In the PHOTO2 exposure, the pixel PX3 is irradiated with light whose main wavelength is a wavelength that is absorbed only by the second dopant material EM2 of the green light emitting layer EML2. As a result, the second dopant material EM2 is decomposed or polymerized or the molecular structure is changed, so that the light emission ability of the EML2 in the region irradiated with light to emit green light is lost. When the light emitting layers EML1 to EML3 have a laminated structure as in the present invention, blue having the highest energy is easily emitted, and the pixel PX3 emits blue light.

  Thus, by performing the exposure process continuously after the deposition of the light-emitting layers EML1 to EML3, it is possible to reduce the number of substrates that are taken in and out of the vacuum deposition apparatus, and the waiting time until the vacuum state is achieved is reduced. Will improve.

Also, the configuration of each organic EL element is not limited to the example shown in FIG. 3. For example, the organic layer ORG has a hole injection layer HIL, a hole transport layer HTL, an electron transport layer ETL, and an electron injection layer EIL. You may do it.
Each organic EL element may include a reflective layer between the pixel electrode PE and the substrate SUB.
Each organic EL element may include an optical matching layer on the counter electrode CE.
Each organic EL element may include an interference condition adjusting layer between the counter electrode CE and the reflective layer.
Each organic EL element may include an uneven scattering layer between the pixel electrode PE and the substrate SUB.
Furthermore, the structure which abbreviate | omitted the partition insulating layer PI (rib) may be sufficient.

  In the above embodiment, the organic EL display device includes three types of organic EL elements having different emission colors. The organic EL display device may include only two types of organic EL elements with different emission colors as the organic EL element, or may include four or more types of organic EL elements with different emission colors.

1 is a plan view schematically showing an organic EL display device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of a structure that can be employed in the display device of FIG. FIG. 3 is a cross-sectional view schematically showing an example of a structure that can be employed in an organic EL element included in the display device of FIG. 2. FIG. 3 is a plan view schematically showing an example of pixel arrangement that can be employed in the display device of FIG. 2. The figure which shows an example of the process flow of the organic EL element of FIG. 3 roughly. The figure which shows the outline of an exposure process. The figure which showed one of the principles which control the luminescent color of the pixel of this invention. The figure which shows schematically the structure of the polarization control element which produces | generates Z polarization component. The figure which shows an example of the polarization control element which produces | generates Z polarization component. The figure which shows an example of the exposure apparatus provided with the polarization control element shown in FIG. The figure which shows schematically the other example of the process flow of the organic EL element of FIG.

Explanation of symbols

  C ... capacitor, CE ... counter electrode, DE ... drain electrode, DL ... video signal line, DP ... display panel, DR ... drive transistor, EA1 ... light emitting part, EA2 ... light emitting part, EA3 ... light emitting part, EIL ... electron injection layer , EML ... light emitting layer, EML1 ... red light emitting layer, EML2 ... green light emitting layer, EML3 ... blue light emitting layer, EM1 ... first dopant material (red light emitting material), EM2 ... second dopant material (green light emitting material), EM3 ... Third dopant material (blue light emitting material), ETL ... electron transport layer, G ... gate, GI ... gate insulating film, HIL ... hole injection layer, HM1 ... first host material, HM2 ... second host material, HM3 ... first 3 host material, HTL ... hole transport layer, II ... interlayer insulating film, ND1 ... power supply terminal, ND1 '... constant potential terminal, ND2 ... power supply terminal, OLED ... organic EL element, ORG ... Physical layer, PE ... pixel electrode, PI ... partition insulating layer, PS ... passivation film, PSL ... power supply line, PX1 ... pixel (red pixel), PX2 ... pixel (green pixel), PX3 ... pixel (blue pixel), SC ... Semiconductor layer, SE ... Source electrode, SL1 ... Scanning signal line, SL2 ... Scanning signal line, SUB ... Insulating substrate, SUB2 ... Sealing substrate, SWa ... Switching transistor, SWb ... Switching transistor, SWc ... Switching transistor, XDR ... Video Signal line driver, YDR ... scanning signal line driver, 100 ... polarization control element, 110 ... polarization modulation element, 120 ... lens, 130 ... array lens.

Claims (9)

Comprising: an insulating substrate; and first to third organic EL elements arranged on the insulating substrate and having different emission colors.
Each of the first to third organic EL elements includes a first electrode, a second electrode facing the first electrode, and an organic material layer interposed between the first electrode and the second electrode. Including
The organic material layer includes a laminate in which first to third light emitting layers having different emission colors are stacked in this order, and is a method of manufacturing an organic EL display device,
When the traveling direction of light is the Z direction and the directions orthogonal to each other in the plane orthogonal to the Z direction are the X direction and the Y direction, the light has a polarization component in the Z direction in addition to the X direction and the Y direction. The manufacturing method of the organic electroluminescence display characterized by having the exposure process which exposes an organic substance layer.   The exposure step includes generating a plurality of linearly polarized light beams having different phases in the XY plane from the radiated light from the light source, and exposing each linearly polarized light with the condensed light. 2. A method for producing an organic EL display device according to 1.   3. The manufacturing of an organic EL display device according to claim 2, wherein the phase difference is [lambda] / (4 * (N-1)) where [lambda] is the wavelength of light and N is an integer of 4 or more. Method.   In the exposure step, a polarization modulation element that generates a plurality of linearly polarized lights in different directions in the XY plane from radiation light from a light source, and a lens that collects each linearly polarized light transmitted through the polarization modulation element, 2. The method of manufacturing an organic EL display device according to claim 1, wherein exposure is performed by applying an exposure apparatus including a combined polarization control element.   The method for manufacturing an organic EL display device according to claim 4, wherein the polarization modulation element is a liquid crystal panel.   5. The polarization modulation element according to claim 4, wherein a region for changing a polarization state of emitted light from a light source is divided into four or more quadrants, and phases of light emitted from the respective quadrant regions are different. Manufacturing method of organic EL display device.   The phase difference between the light emitted from the i-th quadrant region (i = 1 to N−1, N is an integer of 4 or more) of the polarization modulation element and the light emitted from the adjacent (i + 1) -th quadrant region is λ / ( The method of manufacturing an organic EL display device according to claim 6, wherein 4 × (N−1)). The exposure step includes
A first exposure step of exposing a region for forming the second organic EL element and the third organic EL element after forming the first light emitting layer;
A second exposure step of exposing a region for forming the third organic EL element after forming the second light emitting layer;
The manufacturing method of the organic electroluminescence display of Claim 1 characterized by the above-mentioned. The exposure step includes
A first exposure step of exposing a region for forming the second organic EL element and the third organic EL element after forming the third light emitting layer;
A second exposure step of exposing a region for forming the third organic EL element after the first exposure step;
The manufacturing method of the organic electroluminescence display of Claim 1 characterized by the above-mentioned.

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