JP5240115B2 - Method for manufacturing light emitting device - Google Patents

Description

The present invention relates to the production how the light emission device using an organic EL (Electroluminescence) element.

  In recent years, as a next-generation display device following a liquid crystal display (LCD), a light-emitting element type display panel in which self-light-emitting elements such as organic electroluminescence elements (hereinafter abbreviated as “organic EL elements”) are two-dimensionally arranged. Research and development of the light-emitting device provided is underway.

  The organic EL element includes an anode electrode, a cathode electrode, and an organic EL layer (light emitting functional layer) formed between the pair of electrodes and having, for example, a light emitting layer, a hole injection layer, and the like. In the organic EL element, light is emitted by energy generated by recombination of holes and electrons in the light emitting layer.

  The light emitting layer, the hole injection layer, and the like of such an organic EL element are formed by applying a solution to a space partitioned by a partition and drying the solvent, as disclosed in Patent Document 1, for example. Is done. The application of the solution is performed by, for example, a nozzle printing method, an ink jet printing method, or the like.

JP 2005-123083 A

  By the way, in the organic EL element, when the thickness of the light emitting functional layer is not uniform, there is a problem that light emission is not uniform. For this reason, it is required to control the film thickness of the light-emitting functional layer well to obtain a film having good uniformity.

The present invention was made in view of the above, and an object thereof is to provide a manufacturing how the film thickness - emitting device Ru having a light emitting function layer having a good uniformity.

To achieve the above object, a manufacturing method of the light emitting device according to the onset Ming,
A method of manufacturing a light-emitting device in which a plurality of light-emitting elements each having a light-emitting layer that emits light with a predetermined emission color are arranged along a plurality of rows and a plurality of columns,
The light emitting functional layer including the light emitting layer is formed by applying a solution containing an organic material to the formation region of the light emitting layer of the plurality of light emitting elements, and the first light emitting element is used as the plurality of light emitting elements. A light emitting functional layer forming step of alternately forming a plurality of second light emitting elements along the row direction via a gap region;
The light emitting functional layer forming step includes
The light emission of the first light emitting element when the light emitting functional layer is not formed in the formation region of the light emitting layer of the second light emitting element adjacent to both sides in the row direction with respect to the first light emitting element. A functional layer is formed in a formation region of the light emitting layer, and a part of the gap region between the second light emitting element adjacent to the first light emitting element on one side in the row direction and the first light emitting element A first step of forming the first light emitting element so as to straddle a part of the gap region between the second light emitting element adjacent to the other side in the row direction with respect to the first light emitting element;
In the first step, a part of the gap region between the second light emitting element and the first light emitting element adjacent to both sides of the second light emitting element on the both sides in the row direction is the first light emitting element adjacent to the second light emitting element. After a part of the light emitting functional layer is formed, the light emitting functional layer of the second light emitting element is formed in a formation region of the light emitting layer, and one of the second light emitting elements in the row direction is formed with respect to the second light emitting element. A part of the light emitting functional layer formed in the gap region between the first light emitting element adjacent to the first light emitting element and the first light emitting element adjacent to the other side in the row direction with respect to the second light emitting element. A second step of forming so as to cover a part of the light emitting functional layer formed in the gap region between the light emitting element and
Only seen including,
Forming the odd-numbered light emitting elements from one end side in the row direction in the first step;
The even-numbered light emitting elements from the one end side in the row direction are formed in the second step .

The plurality of light emitting elements include a first light emitting layer having a first light emitting color, a second light emitting layer having a second light emitting color different from the first light emitting color, and the first and second light emitting colors. includes a third light-emitting layer having a different third emission color, one of,
And said first light-emitting layer and the second light-emitting layer and the third light-emitting layer, the first light-emitting layer, the second light-emitting layer, as one set in the order of the third light-emitting layer, lined repeated a plurality of sets in the row direction may be placed.

  The light emitting functional layer may include at least one of a hole injection layer for injecting holes into the light emitting layer and an interlayer layer.

In the first step, the application amount of the solution is set to a first amount,
In the second step, the application amount of the solution may be set to a second amount smaller than the first amount.

According to the present invention, when the light emitting functional layer is not formed in the light emitting layer forming region of the light emitting element adjacent to both sides in the row direction, the gap region between the light emitting elements adjacent to both sides in the row direction is provided. A light emitting functional layer is formed in the light emitting layer forming region of the light emitting element adjacent to both sides in the row direction by the first step. A second light emitting functional layer is formed in the light emitting layer forming region so as to cover a part of the light emitting functional layer formed in the gap region between adjacent light emitting elements on both sides in the row direction. by dividing the process, it is possible to provide a manufacturing how the light emission device Ru having a light emitting functional layer thickness has a good uniformity.

It is a top view which shows the structural example of the light-emitting device which concerns on embodiment. (A) And (b) is a figure which shows the electronic device with which a light-emitting device is used. It is a figure which shows the electronic device with which a light-emitting device is used. It is a figure which shows the electronic device with which a light-emitting device is used. It is a figure which shows the cross-sectional structure of the light-emitting device shown in FIG. It is an equivalent circuit diagram of an example of the drive circuit of a pixel. It is a top view of a pixel. It is the VIII-VIII sectional view taken on the line shown in FIG. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows the manufacturing method of a light-emitting device. It is a figure which shows schematic structure of the nozzle printing apparatus for demonstrating a nozzle printing system. It is a figure which shows schematic structure of the nozzle printing apparatus for demonstrating a nozzle printing system. (A) is a figure which shows the cross-sectional structure of the light-emitting device in this embodiment, (b) is a figure which shows the film thickness contour line of each light emitting layer in this embodiment. (A) is a figure which shows the cross-sectional structure of the light-emitting device in a comparative example, (b) is a figure which shows the film thickness contour of each light emitting layer in a comparative example. It is a figure which shows the modification of the manufacturing method of a light-emitting device. It is a figure which shows the modification of the manufacturing method of a light-emitting device. It is a figure which shows the modification of a light-emitting device.

  A light-emitting device, a method for manufacturing a light-emitting device, and an electronic device according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an active drive type light emitting device using a bottom emission type organic EL (electroluminescence) element that emits light generated by the organic EL element to the outside through a substrate on which the organic EL element is formed is taken as an example. I will give you a description. Further, the light emitting device of this embodiment is also used as a display device.

  FIG. 1 is a plan view illustrating a configuration example of a light emitting device according to an embodiment. 2 to 4 illustrate electronic devices in which the light-emitting device is used. FIG. 5 is a diagram illustrating a cross-sectional configuration of the light emitting device 10 illustrated in FIG. 1. FIG. 6 is an equivalent circuit diagram of an example of a drive circuit for the pixel 30. 7 is a plan view of the pixel 30G, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII shown in FIG.

  When the light emitting device 10 performs color display, on the substrate 31, as shown in FIG. 1, each of the three emission colors of red (R), green (G), and blue (B) is used. A set of three pixels 30 (30R, 30G, 30B) each having a light emitting element that emits light, and a plurality of, for example, m pixels are repeatedly arranged in the row direction (left-right direction in FIG. 1), and the column direction ( A plurality of, for example, n pixels having light emitting elements of the same color are arranged in the vertical direction of FIG. In other words, 3m pixels are arranged in the row direction, and 3m × n pixels emitting each color of RGB are arranged in a matrix.

  On the substrate 31, an anode line La arranged in the row direction and connected to the plurality of pixel circuits DS shown in FIG. 6, and a plurality of data lines respectively connected to the plurality of pixel circuits DS arranged in the row direction. Ld and a scanning line Ls for selecting the transistors Tr11 of the plurality of pixel circuits DS arranged in the row direction are formed.

  The light emitting device 10 having such a configuration is used as a display unit (display) of an electronic device such as a digital camera, a personal computer, or a mobile phone. Specifically, the camera 200 includes a lens unit 201, an operation unit 202, a display unit 203, and a viewfinder 204, for example, as shown in FIGS. 2 (a) and 2 (b). The light emitting device 10 is used as the display unit 203. Similarly, as shown in FIG. 3, the personal computer 210 includes a display unit 211 and an operation unit 212, and the light emitting device 10 is used as the display unit 211. Further, the mobile phone 220 includes a display unit 221, an operation unit 222, a reception unit 223, and a transmission unit 224, and the light emitting device 10 is used as the display unit 221.

  Next, FIG. 5 shows a cross-sectional configuration of the light-emitting device 10 shown in FIG. In FIG. 5, for convenience of explanation, the substrate 31, the pixel electrode 42, the partition wall 48, and the three color light emitting layers 45R, 45G, and 45B having red (R), green (G), and blue (B) emission colors, respectively. Only the light-emitting layers 45R, 45G, and 45B (hereinafter collectively referred to as the light-emitting layer 45) are shown, and the other components are not shown. The light emitting layers 45R, 45G, and 45B of the three light emission colors form the light emitting elements of the three color pixels 30R, 30G, and 30B, respectively. As will be described in detail later, in this embodiment, after the light emitting layers 45 are formed in every other row in the first step, the light emitting layers 45 are formed in the rows that are not formed in the first step in the second step. Form. Specifically, for example, the light-emitting layers 45 in the odd-numbered columns from the left end in FIG. 5 are formed, and then the light-emitting layers 45 in the even-numbered columns are formed. For this reason, the light emitting layers 45R, 45G, and 45B of R, G, and B colors are not formed in the order of R, G, and B. For example, as shown in FIG. 5, the light emitting layer 45G of the even-numbered pixel 30G is formed after the light-emitting layer 45R of the odd-numbered pixel 30R and the light-emitting layer 45B of the pixel 30B, which are adjacent to each other. As shown in FIG. 5, the upper surface of the partition wall 48 is higher than the upper surface of the flat portion at the center of the light emitting layers 45R, 45G, and 45B. Further, as shown in FIG. 5, both ends of the light emitting layers 45R, 45G, and 45B in the row direction are formed so as to partially run on the partition walls 48. Accordingly, in FIG. 5, the end of the pixel 30 </ b> G riding on the partition wall 48 of the light emitting layer 45 </ b> G covers the end of the pixel 30 </ b> R riding on the partition wall 48 of the pixel 30 </ b> R and the light emitting layer 45 </ b> B of the pixel 30 </ b> B. The light emitting layers 45 </ b> R and the light emitting layers 45 </ b> B are formed so as to run over the ends.

  Next, the pixels 30 constituting the light emitting device 10 will be described with reference to FIGS. In the present embodiment, R, R, and R except that the end of the light emitting layer 45 of the odd-numbered pixels 30 on the partition wall 48 is formed so as to cover the end of the adjacent pixel 30 on the partition wall 48. Since the configurations of the G and B pixels 30 are the same, the G pixel 30G will be described below as an example.

  The pixel 30 has a pixel circuit DS. For example, as illustrated in FIG. 6, the pixel circuit DS includes a selection transistor Tr11, a drive transistor Tr12, a capacitor Cs, and an organic EL element (light emitting element) OEL.

  As shown in FIG. 6, the selection transistor Tr11 has a gate terminal connected to the scanning line Ls, a drain terminal connected to the data line Ld, and a source terminal connected to the contact N11. The drive transistor Tr12 has a gate terminal connected to the contact N11, a drain terminal connected to the anode line La, and a source terminal connected to the contact N12. The capacitor Cs is connected to the gate terminal and the source terminal of the drive transistor Tr12. Note that the capacitor Cs is an auxiliary capacitance additionally provided between the gate and the source of the driving transistor Tr12 or a capacitance component including a parasitic capacitance and an auxiliary capacitance between the gate and the source of the driving transistor Tr12. In the organic EL element OEL, the anode terminal (pixel electrode 42) is connected to the contact N12, and the reference voltage Vss is applied to the cathode terminal (counter electrode 46).

  The scanning line Ls is connected to a scanning driver (not shown) arranged on the peripheral edge of the pixel substrate, and a selection voltage for setting a plurality of pixels 30 arranged in the row direction at a predetermined timing to a selected state. A signal (scanning signal) is applied. The data line Ld is connected to a data driver (not shown) arranged at the peripheral edge of the pixel substrate, and a data voltage (grayscale signal) corresponding to light emission data at a timing synchronized with the selection state of the pixel 30. Is applied. A plurality of drive transistors Tr12 arranged in the row direction are set to a state in which a drive current corresponding to light emission data flows through the pixel electrode 42 (for example, an anode terminal) of the organic EL element OEL connected to the drive transistor Tr12. The anode line La (supply voltage line) is directly or indirectly connected to a predetermined high potential power source. In other words, the anode line La is applied with a predetermined high potential (supply voltage Vdd) sufficiently higher than the reference voltage Vss applied to the counter electrode 46 of the organic EL element OEL. The counter electrode 46 is directly or indirectly connected to, for example, a predetermined low potential power source, and is formed of a single electrode layer for all the pixels 30 arranged in an array on the substrate 31. The predetermined low voltage (reference voltage Vss, for example, ground potential GND) is set to be applied in common.

  The anode line La and the scanning line Ls are formed together with the source electrode and the drain electrode by using a source-drain conductive layer that forms the source electrode and the drain electrode of each of the transistors Tr11 and Tr12. The data line Ld is formed together with the gate electrode using a gate conductive layer that becomes a gate electrode of each of the transistors Tr11 and Tr12. As shown in FIG. 7, a contact hole 61 is formed in the insulating film 32 between the data line Ld and the drain electrode Tr11d, and the data line Ld and the drain electrode Tr11d are conducted through the contact hole 61. . Contact holes 62 and 63 are respectively formed in the insulating film 32 between the scanning line Ls and both ends of the gate electrode Tr11g, and the scanning line Ls and the gate electrode Tr11g are electrically connected through the contact holes 62 and 63. . A contact hole 64 is formed in the insulating film 32 between the source electrode Tr11s and the gate electrode Tr12g, and the source electrode Tr11s and the gate electrode Tr12g are electrically connected via the contact hole 64. The insulating film 32 is formed of an insulating material, such as a silicon oxide film or a silicon nitride film, and is formed on the substrate 31 so as to cover the data line Ld, the gate electrode Tr11g, and the gate electrode Tr12g.

  Next, as shown in FIG. 8, the organic EL element OEL includes a pixel electrode 42, a light emitting layer 45, and a counter electrode 46. In FIG. 8, for the sake of convenience of explanation, a configuration including only the light emitting layer 45 as a light emitting functional layer that contributes to light emission is taken as an example. However, the present invention is not limited to this, and as shown in FIG. May include a hole injection layer 43 and a light emitting layer 45, and may further include a hole injection layer 43, an interlayer layer 44, and a light emitting layer 45.

  On the substrate 31 of each pixel, a selection transistor Tr11 obtained by patterning a gate conductive layer and gate electrodes Tr11g and Tr12g of the drive transistor Tr12 are formed. On the substrate 31 adjacent to each pixel, a data line Ld extending in the column direction is formed by patterning the gate conductive layer.

  The pixel electrode (anode electrode) 42 is made of a conductive material having translucency, for example, ITO (Indium Tin Oxide), ZnO, or the like. Each pixel electrode 42 is insulated from the pixel electrode 42 of another adjacent pixel 30 by an interlayer insulating film 47.

  The interlayer insulating film 47 is made of an insulating material such as a silicon nitride film. The interlayer insulating film 47 is formed between the pixel electrodes 42 and insulates and protects the transistors Tr11 and Tr12, the scanning line Ls, and the anode line La. A substantially rectangular opening 47a is formed in the interlayer insulating film 47, and the light emitting region of the pixel 30 is defined by the opening 47a. Further, a partition wall 48 is formed on the interlayer insulating film 47. The partition wall 48 is formed with a groove-shaped opening 48 a extending in the column direction (vertical direction in FIG. 7) over the plurality of pixels 30. Here, the interlayer insulating film 47 and the partition wall 48 formed thereon form a gap region between the light emitting regions of the pixels 30 arranged adjacent to each other in the row direction.

  The partition wall 48 is formed by curing an insulating material, for example, a photosensitive resin such as polyimide, and is formed on the interlayer insulating film 47. As shown in FIG. 7, the partition wall 48 is formed in a stripe shape so as to open the pixel electrodes 42 of a plurality of pixels along the column direction. The planar shape of the partition wall 48 is not limited to this, and may be a lattice shape having an opening for each pixel electrode 42. The upper surface of the partition wall 48 is formed to be higher than the upper surface of the flat portion at the center of the light emitting layers 45R, 45G, and 45B.

  Note that the surface of the partition wall 48 and the surface of the interlayer insulating film 47 may be subjected to a liquid repellent treatment. Here, the liquid repellency indicates the property of repelling both aqueous solvents and organic solvents.

  The light emitting layer 45 is formed on the pixel electrode (anode electrode) 42. The light emitting layer 45 has a function of generating light of a predetermined emission color by applying a voltage between the anode electrode 42 and the cathode electrode 46. The light emitting layer 45 is made of a known polymer light emitting material capable of emitting fluorescence or phosphorescence, for example, a light emitting material containing a conjugated double bond polymer such as polyparaphenylene vinylene or polyfluorene. In addition, these luminescent materials are appropriately coated with a solution (dispersion) dissolved (or dispersed) in an aqueous solvent or an organic solvent such as tetralin, tetramethylbenzene, mesitylene, and xylene by a nozzle printing method, an inkjet printing method, or the like. Formed by volatilizing the solvent.

  The present embodiment is characterized in that the formation process of the light emitting layer 45 is divided into two and the light emitting layer 45 is formed by thinning out the light emitting layer 45 once every other column, and then the thinned light emitting layer 45 is formed. . For this reason, the light emitting layer 45 of each color of R, G, B is not formed in the order of R, G, B. Therefore, for example, as shown in FIG. 5, the light emitting layer 45G of the even-numbered pixel 30G is formed after forming the light-emitting layer 45R of the odd-numbered pixel 30R and the light-emitting layer 45B of the odd-numbered pixel 30B. . Accordingly, in FIG. 5, the end of the pixel 30 </ b> G riding on the partition wall 48 of the light emitting layer 45 </ b> G covers a part of the end of the pixel 30 </ b> R riding on the partition wall 48 of the pixel 30 </ b> R and the light emitting layer 45 </ b> B of the pixel 30 </ b> B. The light emitting layer 45 </ b> R of the pixel 30 </ b> R and the light emitting layer 45 </ b> B of the pixel 30 </ b> B are formed so as to ride on part of the end of the light emitting layer 45 </ b> B.

Here, when a hole injection layer is provided as the light emitting functional layer, the hole injection layer 43 is provided between the pixel electrode 42 and the light emitting layer 45 as shown in FIG. The hole injection layer 43 has a function of supplying holes to the light emitting layer 45. The hole injection layer 43 is made of an organic polymer material capable of injecting and transporting holes, for example, polyethylene dioxythiophene (PEDOT) as a conductive polymer and polystyrene sulfonic acid (PSS) as a dopant. The
Further, when an interlayer layer is provided as the light emitting functional layer, the interlayer layer 44 is provided between the hole injection layer 43 and the light emitting layer 45 as shown in FIG. The interlayer layer 44 has a function of suppressing the hole injection property of the hole injection layer 43 to facilitate recombination of electrons and holes in the light emitting layer 45, and increases the light emission efficiency of the light emitting layer 45.

  Further, in the case of the bottom emission type, the counter electrode (cathode electrode) 46 is provided on the light emitting layer 45 side, and is an electron injecting lower layer made of a conductive material, for example, a material having a low work function such as Li, Mg, Ca, Ba or the like. And a laminated structure having an upper layer made of a light-reflective conductive metal such as Al. In the present embodiment, the counter electrode 46 is composed of a single electrode layer formed across a plurality of pixels 30, and for example, a reference voltage Vss which is a ground potential is applied. When the organic EL element OEL is a top emission type, the counter electrode 46 is provided on the light emitting layer 45 side and is an extremely thin material having a thickness of about 10 nm, such as Li, Mg, Ca, Ba, etc. A transparent laminated structure having a light transmissive low work function layer made of and a light reflective conductive layer such as ITO having a film thickness of about 100 nm to 200 nm.

  Next, a method for manufacturing the light emitting device according to the present embodiment will be described with reference to FIGS. 9A to 9I, FIG. 10A, and FIG. 10B. 10A and 10B are diagrams illustrating a schematic configuration of a nozzle printing apparatus for explaining a nozzle printing method. As shown in FIG. 10A, the nozzle printing apparatus generally includes a nozzle head 50 having a nozzle that continuously discharges a solution 52 made of an organic compound-containing liquid, and the nozzle head 50 is arranged along a coating region on the substrate 31. By moving, the solution 52 is applied to the application region on the substrate 31. 10A shows a configuration in the case where only one nozzle head 50 is provided, and FIG. 10B shows a configuration in the case where two nozzle heads 50 are provided. 10A and 10B are arranged in an orientation in which the vertical direction in FIG. 7 is the horizontal direction in FIGS. 10A and 10B. Here, FIG. 10B shows the case where the nozzle printing apparatus has two nozzle heads 50, but the present invention is not limited to this, and the nozzle printing apparatus may have three or more nozzle heads 50. Since the selection transistor Tr11 is formed in the same process as the driving transistor Tr12, a part of the description of the formation of the selection transistor Tr11 is omitted.

  As shown in FIG. 9A, first, a substrate 31 made of a glass substrate or the like is prepared. Next, on the substrate 31, for example, a Mo film, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film or an AlNdTi alloy film, an AlNi alloy film, a MoNb alloy film, etc. A gate conductive film is formed and patterned into the shape of the gate electrode Tr12g of the drive transistor Tr12 as shown in FIG. 9A. At this time, although not shown, the gate electrode Tr11g of the selection transistor Tr11 and the data line Ld are also formed. Subsequently, as shown in FIG. 9B, an insulating film 32 is formed on the gate electrode Tr12g and the data line Ld by a CVD (Chemical Vapor Deposition) method or the like.

  Next, a semiconductor layer made of amorphous silicon or the like is formed on the insulating film 32 by a CVD method or the like. Next, an insulating film made of, for example, SiN is formed on the semiconductor layer by a CVD method or the like. Subsequently, the insulating film is patterned by photolithography or the like to form the stopper film 115. Further, a film made of amorphous silicon or the like containing n-type impurities is formed on the semiconductor layer and the stopper film 115 by a CVD method or the like, and this film and the semiconductor layer are patterned by photolithography or the like. As shown in FIG. 9B, the semiconductor layer 114 and the ohmic contact layers 116 and 117 are formed.

  Next, a transparent conductive film such as ITO or a light-reflective conductive film and a transparent conductive film such as ITO are coated on the insulating film 32 by sputtering, vacuum deposition, or the like, and then patterned by photolithography to be pixel electrodes 42. Form.

  Subsequently, after forming contact holes 61 to 64 as through holes in the insulating film 32, for example, a Mo film, a Cr film, an Al film, a Cr / Al laminated film, an AlTi alloy film, an AlNdTi alloy film, or an AlNi alloy film. Then, a source-drain conductive film made of a MoNb alloy film or the like is coated by a sputtering method, a vacuum deposition method, or the like, and patterned by photolithography to form a drain electrode Tr12d and a source electrode Tr12s as shown in FIG. 9B. At the same time, the anode line La is formed. At this time, the source electrode Tr12s of the drive transistor Tr12 is formed so as to overlap with a part of the pixel electrode 42, respectively.

  Subsequently, as shown in FIG. 9C, an interlayer insulating film 47 made of a silicon nitride film is formed by a CVD method or the like so as to cover the driving transistor Tr12 and the like, and then an opening 47a is formed by photolithography. Next, photosensitive polyimide is applied so as to cover the interlayer insulating film 47, patterned by exposure and development through a mask corresponding to the shape of the partition wall 48, and has an opening 48a as shown in FIG. 9C. A partition wall 48 is formed.

  Subsequently, when forming the hole injection layer as the light emitting functional layer, the nozzle printing apparatus shown in FIG. 10A or 10B that continuously discharges the organic compound-containing liquid containing the hole injection material as the solution 52 from the nozzle head 50. Alternatively, it is selectively applied onto the pixel electrode 42 surrounded by the opening 47a by an ink jet apparatus that intermittently discharges the ink as a plurality of independent droplets. Subsequently, the substrate 31 is heated in an air atmosphere to volatilize the solvent of the organic compound-containing liquid, thereby forming the hole injection layer 43. The organic compound-containing liquid may be applied in a heated atmosphere.

  Further, when an interlayer layer is formed as the light emitting functional layer, an organic compound-containing liquid containing a material that becomes the interlayer layer 44 is continuously discharged from the nozzle head 50 as the solution 52, as shown in FIG. 10A or FIG. 10B. It coats on hole injection layer 43 using a nozzle printing device or an ink jet device. Subsequently, heat drying in a nitrogen atmosphere or heat drying in a vacuum is performed, and the residual solvent is removed to form the interlayer layer 44. The organic compound-containing liquid may be applied in a heated atmosphere.

  Next, in order to form the light emitting layer 45 as the light emitting functional layer, the organic compound-containing liquid containing the light emitting polymer material (R, G, B) is continuously discharged from the nozzle head 50 as the solution 52. FIG. Using a nozzle printing method by a nozzle printing apparatus shown in FIG. 10B, coating is performed on the pixel electrode 42 provided between the partition walls 48 and surrounded by the opening 47a. The application is performed along the direction in which the partition wall 48 is formed (the vertical direction in FIGS. 7 and 9D to 9I).

Here, the formation method of the light emitting layer 45 in this embodiment is demonstrated in detail.
In the present embodiment, the formation of the light emitting layer 45 is divided into a first step of forming the light emitting layer 45 every other column and a second step of forming the light emitting layer 45 in the column not formed in the first step. And do it. Each process will be described below with reference to FIGS. 9D to 9I. In FIG. 9D to FIG. 9I, for convenience of explanation, the column to which the organic compound-containing liquid for forming the light emitting layer 45 is applied is shown in dark color. Furthermore, the column in which the formation of the light emitting layer 45 is completed is indicated by a solid line, and the column in which the light emitting layer 45 is not formed is indicated by a broken line.

  Further, as described above, the pixels 30 are arranged in the column direction (vertical direction shown in FIG. 1) for each of R, G, and B colors. As shown in FIG. 9D, each column of R, G, and B is set as a set, and each column is divided into R1, G1, B1, R2, G2, B2, R3, G3, B3,. . . , Rm-1, Gm-1, Bm-1, Rm, Gm, Bm and the color and set number. Here, although the case where m is an even number is described as an example in the present embodiment, m may be an odd number.

  In the first step, first, an organic compound-containing liquid (solution 52) containing a light-emitting polymer material (R) is applied to an odd-numbered set of R-color columns by a nozzle printing device that continuously discharges the solution 52. Apply. Specifically, as shown in FIG. 9D, the coating is applied every 5 rows up to Rm−1 in the order of R1 and R3. At this time, as shown in FIG. 10A, the solution 52 is discharged from the nozzles of the nozzle head 50 and applied onto the substrate 31. The nozzle head 50 moves along the direction in which the partition wall 48 is formed (the left-right direction in FIG. 10A) while discharging the solution 52 between the partition walls 48. In addition, when performing application | coating to each row | line | column continuously, as shown to FIG. 10A, while the nozzle head 50 exists outside the board | substrate 31, the direction orthogonal to the direction in which the partition 48 was formed (FIG. 10A is moved in a vertical direction) by a predetermined distance. By repeating this, the solution 52 is applied to a predetermined row. Note that while the nozzle head 50 is outside the substrate 31, the solution 52 may be discharged, or the discharge may be temporarily stopped. Here, as shown in FIG. 10A, when the nozzle printing apparatus has only one nozzle head 50, the moving direction of the nozzle head 50 is changed for each row of R1, R3,. Apply alternately. As shown in FIG. 10B, when the nozzle printing apparatus has two nozzle heads 50, the nozzles are provided for every two rows of R1 and R3, R5 and R7,..., Rm-3 and Rm-1. Application is performed by alternately changing the moving direction of the head 50. The same operation is performed in the following. Instead of moving the substrate 31, the nozzle head 50 may be moved by a predetermined distance in a direction orthogonal to the direction in which the partition walls 48 are formed.

  Next, an organic compound-containing liquid containing the light-emitting polymer material (B) is applied to the odd-numbered B-color columns by a nozzle printing apparatus that continuously discharges. Specifically, as shown in FIG. 9E, the coating is applied every 5 rows up to Bm−1 in the order of B1 and B3.

  Further, an organic compound-containing liquid containing the light-emitting polymer material (G) is applied to the even-numbered G-color columns by a nozzle printing apparatus that continuously discharges. Specifically, as shown in FIG. 9F, coating is performed every 5 rows up to Gm in the order of G2 and G4.

  In this way, in the first step, the organic compound-containing liquid is applied to the odd-numbered R color columns, the odd-numbered B color columns, and the even-numbered G color columns. That is, as shown in FIG. 9D to FIG. 9F, in the step of applying the odd-numbered R-color columns in the first step, as seen from the column numbers counted from the left end, regardless of the emission color of the light-emitting layer, The light emitting layers are formed in the order of the first row and the seventh row, and the light emitting layers are formed in the order of the third row and the ninth row in the step of applying the odd number of B color rows, and the even number of G color rows. In the step of applying, the light emitting layer is formed in the order of the fifth column and the eleventh column. As a result, when the first process is considered as a whole, the odd-numbered light emitting layers are formed in every other column, such as the first column, the third column, the fifth column, the seventh column, the ninth column,. Yes.

  Next, in the second step, first, an organic compound-containing liquid containing the light emitting polymer material (G) is applied to an odd group of G color columns by a nozzle printing apparatus that continuously discharges. Specifically, as shown in FIG. 9G, coating is performed up to Gm-1 every 5 rows in the order of G1 and G3.

  Subsequently, an organic compound-containing liquid containing the light-emitting polymer material (R) is applied to the even-numbered R-color columns by a nozzle printing apparatus that continuously discharges. Specifically, as shown in FIG. 9H, coating is performed up to Rm in the order of R2 and R4.

  Further, the organic compound-containing liquid containing the light emitting polymer material (B) is applied to the even-numbered B-color columns by a nozzle printing apparatus that continuously discharges the liquid. Specifically, as shown in FIG. 9I, the coating is applied up to Bm in the order of B2 and B4.

  As described above, in the second step, the organic compound-containing liquid is applied to the odd-numbered G color columns, the even-numbered R color columns, and the even-numbered B color columns. That is, as shown in FIG. 9G to FIG. 9I, in the step of applying the odd number of G color columns in the second step, as viewed from the column numbers counted from the left, regardless of the emission color of the light emitting layer, The light emitting layers are formed in the order of the second row and the eighth row, and in the step of applying the even number of R color rows, the light emitting layers are formed in the order of the fourth row and the tenth row, and the even number of B color rows. In the step of applying, the light emitting layer is formed in the order of the sixth column and the twelfth column. That is, when the second step is taken as a whole, the light emitting layer 45 is formed in the first step, ie, the second column, the fourth column, the sixth column, the eighth column, the tenth column, the twelfth column,. The light emitting layers 45 are formed in the even-numbered columns that did not exist.

  If the color applied last in the first step is the same as the color applied first in the second step, it is not necessary to change the nozzle of the nozzle printing apparatus, which is efficient and preferable.

  Here, since a part of the organic compound-containing liquid applied in the first step is formed on the upper part of the partition wall 48 to form the light emitting layer 45, the height of the partition wall 48 is increased by the thickness of the light emitting layer 45. Get higher. In this case, if the discharge amount of the organic compound-containing liquid in the second step is the same as the discharge amount in the first step, it is applied in the second step because the height of the partition wall 48 is increased. The amount of the organic compound-containing liquid that runs on the upper portion of the partition wall 48 is smaller than that of the organic compound-containing liquid applied in the first step. As a result, the organic compound-containing liquid applied in the second step accumulates more between the partition walls 48 than the organic compound-containing liquid applied in the first step, and the light emitting layer formed in the second step The film thickness may be greater than the film thickness of the light emitting layer formed in the first step. For this reason, you may make it reduce the discharge amount of the organic compound containing liquid in a 2nd process rather than the discharge amount in a 1st process. Thereby, the film thickness of the light emitting layer formed in the first step and the film thickness of the light emitting layer formed in the second step can be made uniform.

  Subsequently, as shown in FIG. 8, a layer made of a material having a low work function such as Li, Mg, Ca, Ba and the like and a light reflective property such as Al are formed on the substrate 31 formed up to the light emitting layer 45 by vacuum deposition or sputtering. A counter electrode 46 having a two-layer structure made of a conductive layer is formed.

Next, a sealing resin made of an ultraviolet curable resin or a thermosetting resin is applied on the substrate 31 outside the light emitting region where the plurality of pixels 30 are formed, and the sealing substrate (not shown) and the substrate 31 are bonded together. Next, the sealing resin is cured by ultraviolet rays or heat, and the substrate 31 and the sealing substrate are bonded.
From the above, the light emitting device 10 is manufactured.

  As described above, in the present embodiment, after the light emitting layers 45 of the light emitting functional layer are formed in every other row in the first step, the light emitting layer is formed in the second step in a row not formed in the first step. 45 is formed. Thereby, the light emitting layer 45 can be made into a film having good uniformity.

  Here, the effect by embodiment of this invention is demonstrated. The nozzle printing method is a method in which a solution is continuously ejected from a nozzle head, and a liquid column is continuously formed and applied. Therefore, printing can be performed at a higher speed than an ink jet printing method in which a solution is intermittently ejected. is there. On the other hand, when forming the RGB light emitting layer by the nozzle printing method, it is necessary to apply the solution so that the solution is contained in the partition wall in order to avoid color mixing. Furthermore, in order to improve the display characteristics, it is necessary to satisfactorily control the light emitting functional layer thickness inside the partition walls. For this reason, for example, it is ideal that a hydrophobic treatment is performed on the partition before coating so that the organic compound-containing liquid does not remain on the partition. However, it is necessary to narrow the discharge amount from the nozzle in order to apply the ink so that the pixel density is improved and the ink is not left on the partition wall of the panel with high definition. When the discharge amount from the nozzle is reduced, the discharge stability is deteriorated. Furthermore, if the nozzle diameter is narrowed down, the piping is likely to be clogged, the number of maintenance increases, and there is a demerit that productivity decreases. Therefore, in practice, it is unavoidable that the solution remains on the partition in the application of the solution. And even in such a case, it is required to have a film thickness with good uniformity. Note that these are not limited to the nozzle printing method, and the same problem exists even in other printing methods.

  Here, in a configuration in which the applied solution remains on the partition walls, the R light emitting layer 45R is applied to the entire row, the G light emitting layer 45G is applied to the entire row, and then the B light emission is performed. The configuration in which the RGB light emitting layer is formed by applying the layer 45B to all the rows will be described as a comparative example, and the effect of this embodiment when compared with this will be described.

  FIG. 11A is a diagram showing a cross-sectional configuration of the light emitting device 10 in the present embodiment, and FIG. 11B is a diagram showing film thickness contour lines of each light emitting layer 45 in the present embodiment. FIG. 12A is a diagram illustrating a cross-sectional configuration of a light emitting device in a comparative example, and FIG. 12B is a diagram illustrating a film thickness contour of each light emitting layer in the comparative example.

  In the case of the comparative example, as shown in FIGS. 12A and 12B, the thicknesses of the G light emitting layer and the B light emitting layer to be applied later are hardly uniform. This is due to the fact that the organic compound-containing liquid for forming the light emitting layer is more easily adapted on the light emitting layer than on the partition. That is, when the G light emitting layer is applied after the R light emitting layer is applied in all rows, the organic compound-containing liquid for forming the G light emitting layer is easily pulled toward the R light emitting layer side. Thereby, in the G light emitting layer, the drying speed of the organic compound-containing liquid differs particularly in the left-right direction shown in FIG. 12A, and as schematically shown in FIG. The film thickness on the R color side becomes thick, and the film thickness on the left and right is asymmetric. The same applies to the B-color light-emitting layer, and the thickness of the previously formed G-color light-emitting layer is thick, and the left and right are asymmetric.

  On the other hand, if the light emitting layers 45 are formed in every other row as in this embodiment, and then the light emitting layers 45 are formed in the remaining rows, the drying rate can be made more uniform. For example, an R-color light-emitting layer 45R and a B-color light-emitting layer 45B are formed in advance, and then a G-color organic compound-containing liquid is applied. Even if the G-color organic compound-containing liquid is applied on the R-color light-emitting layer 45R and the B-color light-emitting layer 45B, the liquid is easily compatible with any of the light-emitting layers. The drying speed is not different in the left-right direction shown in FIG. Therefore, as shown in FIG. 11B, the G light emitting layer 45G has a substantially uniform thickness on the left and right. Also, the R-color light-emitting layer 45R and B-color light-emitting layer 45B, which are formed in advance every other row, are formed in a state where no light-emitting layer is formed on the partition wall 48. There is no balance. Therefore, the right and left light-emitting layers 45R and the B-color light-emitting layer 45B can also have a substantially symmetrical film thickness.

  In the above-described embodiment, the odd-numbered group of R, the odd-numbered group of B, and the even-numbered group of G are sequentially formed in the first step, and the odd-numbered group of G and the even-numbered group of R are formed in the second step. The structure in which the light emitting layers 45 of the even number B are formed in order has been described as an example, but is not limited thereto. For example, in the first step, the odd-numbered group of G, the even-numbered group of R, and the even-numbered group of B are formed in order, and in the second step, the odd-numbered group of R, the odd-numbered group of B, and the even-numbered group of G The light emitting layer 45 may be formed in order. In short, it may be applied every other row in the entire first step.

  Further, the order of forming the light emitting layers 45 of the odd group of R, the odd group of B, and the even group of G in the first step can be arbitrarily changed. Similarly, the order of forming the light emitting layers 45 of the odd group of G, the even group of R, and the even group of B in the second step can be arbitrarily changed.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible. For example, in the above-described embodiment, the light emitting device 10 performs color display, and the configuration including the three color light emitting elements has been described as an example. However, the light emitting device 10 performs monochromatic display. Only one color light emitting element is provided. In this case, as shown in FIGS. 13A and 13B, out of the light emitting layers having up to l columns, the odd columns may be applied in the first step and the even columns may be applied in the second step. Or you may make it apply | coat an even number row | line in a 1st process and an odd number line | wire in a 2nd process. The discharge amount is the same as that in the above-described embodiment, and the discharge amount in the second step may be increased in order to make the thickness of the light emitting layer uniform.

  In the above-described embodiment, the light emitting functional layer has a configuration including only the light emitting layer, but is not limited thereto, and may further include a hole injection layer, an interlayer layer, and the like. Moreover, as shown in FIG. 14, when forming these hole injection layers 43 and interlayer layers 44, it can also apply | coat every other row similarly to this embodiment. When the manufacturing method of the present embodiment is used for the hole injection layer 43 and the interlayer layer 44, the end of the hole injection layer 43 covers the end of the adjacent hole injection layer 43 as shown in FIG. It is formed. Similarly, the interlayer layer 44 is formed so as to cover the end of the adjacent interlayer layer 44.

  In addition, when using for a positive hole injection layer and an interlayer layer, even if it is a case where the light emitting layer of several colors is provided, it can form from a common material. Therefore, as shown in FIGS. 13A and 13B, the odd number columns may be applied in the first step, the even number columns may be applied in the second step, the even number columns in the first step, and the odd number columns in the second step. May be applied.

  In the embodiment described above, the pixel circuit DS has a configuration including two transistors as an example. However, the pixel circuit DS may include three or more transistors.

  In the above-described embodiments, the bottom emission type organic EL element has been mainly described. However, the present invention is not limited to this, and the top emission type organic EL element that emits light generated by the organic EL element OEL to the outside through the counter electrode 40 is not limited thereto. It can also be used for EL elements.

  In each of the above-described embodiments, the configuration in which the light emitting device is used as a display device has been described as an example. However, it can also be used as an exposure device such as a printer head that irradiates light to a photosensitive drum of a printer.

  Further, in the above-described embodiment, a configuration including light emitting elements of three colors R, G, and B is given as an example, but the number may be more than three colors or two colors.

  DESCRIPTION OF SYMBOLS 10 ... Light-emitting device, 30, 30R, 30G, 30B ... Pixel, 31 ... Substrate, 32 ... Insulating film, 42 ... Pixel electrode (anode electrode), 43 ... Hole injection Layer, 44... Interlayer layer, 45R, 45G, 45B... Luminescent layer, 46. Counter electrode (cathode electrode), 47 .. interlayer insulating film, 48. Nozzle head, 52 ... solution, 114 ... semiconductor layer, 115 ... stopper film, 116,117 ... ohmic contact layer, Tr11d, Tr12d ... drain electrode, Tr11g, Tr12g ... gate electrode , Tr11s, Tr12s ... Source electrode, La ... Anode line, Ls ... Scan line, Ld ... Data line, Tr11 ... Selection transistor, Tr12 ... Drive gate Njisuta

Claims (4)

A method of manufacturing a light-emitting device in which a plurality of light-emitting elements each having a light-emitting layer that emits light with a predetermined emission color are arranged along a plurality of rows and a plurality of columns,
The light emitting functional layer including the light emitting layer is formed by applying a solution containing an organic material to the formation region of the light emitting layer of the plurality of light emitting elements, and the first light emitting element is used as the plurality of light emitting elements. A light emitting functional layer forming step of alternately forming a plurality of second light emitting elements along the row direction via a gap region;
The light emitting functional layer forming step includes
The light emission of the first light emitting element when the light emitting functional layer is not formed in the formation region of the light emitting layer of the second light emitting element adjacent to both sides in the row direction with respect to the first light emitting element. A functional layer is formed in a formation region of the light emitting layer, and a part of the gap region between the second light emitting element adjacent to the first light emitting element on one side in the row direction and the first light emitting element A first step of forming the first light emitting element so as to straddle a part of the gap region between the second light emitting element adjacent to the other side in the row direction with respect to the first light emitting element;
In the first step, a part of the gap region between the second light emitting element and the first light emitting element adjacent to both sides of the second light emitting element on the both sides in the row direction is the first light emitting element adjacent to the second light emitting element. After a part of the light emitting functional layer is formed, the light emitting functional layer of the second light emitting element is formed in a formation region of the light emitting layer, and one of the second light emitting elements in the row direction is formed with respect to the second light emitting element. A part of the light emitting functional layer formed in the gap region between the first light emitting element adjacent to the first light emitting element and the first light emitting element adjacent to the other side in the row direction with respect to the second light emitting element. A second step of forming so as to cover a part of the light emitting functional layer formed in the gap region between the light emitting element and
Only seen including,
Forming the odd-numbered light emitting elements from one end side in the row direction in the first step;
An even-numbered light emitting element from the one end side in the row direction is formed in the second step . The plurality of light emitting elements include a first light emitting layer having a first light emitting color, a second light emitting layer having a second light emitting color different from the first light emitting color, and the first and second light emitting colors. includes a third light-emitting layer having a different third emission color, one of,
And said first light-emitting layer and the second light-emitting layer and the third light-emitting layer, the first light-emitting layer, the second light-emitting layer, as one set in the order of the third light-emitting layer, method of manufacturing a light emitting device according to claim 1, wherein the placement to Rukoto lined repeated a plurality of pairs in a row direction. The method for manufacturing a light emitting device according to claim 1 , wherein the light emitting functional layer includes at least one of a hole injection layer for injecting holes into the light emitting layer and an interlayer layer. In the first step, the application amount of the solution is set to a first amount,
In the second step, the method of manufacturing the light emitting device according to any one of claims 1 to 3, characterized in that setting the coating amount of the solution to the second amount less than the first amount .

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