JP2009093848A - Defect inspection method and defect detecting device for electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect inspection device for electroluminescent element capable of surely discriminating RGB colors, and is further, capable of inspecting a plurality of pixel areas on a manufacturing line. <P>SOLUTION: The defect inspection device for the electroluminescent element is provided with a droplet application part (20Re) applying light-emitting droplets at pixel areas between barrier ribs of a substrate formed by imprinting; an irradiating part (UV) irradiating light of a wavelength of 500 nm or less on a light-emitting layer by light-emitting droplets; an observation means (CCD) capable of observing a detection range subdivided from pixel areas for observing phosphor light from the light-emitting layer via an optical filter that makes visible light transmit, and a defective point specifying parts (96) for specifying defective points of the light-emitting layer, based on results of observation steps. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an EL (electroluminescence) element, and relates to a defect inspection method and a defect detection apparatus for the EL element.

  As a display device replacing a liquid crystal display, the effectiveness of an organic EL element (organic electroluminescence element) is said. Since the organic EL element is a self-luminous type, a backlight such as a liquid crystal display is unnecessary. For this reason, power consumption is reduced as compared with a liquid crystal display, a wide viewing angle, and quick response. Therefore, research and development have been actively conducted as a next-generation display element.

In order to produce a full-color organic EL element, it is necessary to separately coat RGB pixels with light emitting layers of different colors. Patent Document 1 discloses an organic EL layer in which an organic EL material is applied by an inkjet method when an RGB light emitting layer is formed, and then the organic EL layer is irradiated with ultraviolet rays by a fluorescent camera to image fluorescence from the organic EL layer. A forming apparatus is disclosed.
JP 2004-228006 A

  However, the organic EL layer forming apparatus of Patent Document 1 does not disclose a specific configuration to the extent that it discloses that the fluorescent camera is configured with a CCD element. Further, since a configuration in which one inkjet nozzle and one fluorescent camera are arranged for each pixel is disclosed, mass productivity is poor, and the organic EL layer forming apparatus disclosed in Patent Document 1 is actually a production line. It can not be used in.

  Therefore, the present invention provides a defect inspection method and a defect inspection apparatus for an electroluminescence element that can reliably identify RGB colors and can inspect a plurality of pixel regions on a production line.

In the defect inspection method for an electroluminescence element according to the first aspect of the present invention, a luminescent droplet is applied to a pixel region of a substrate by a droplet application unit, and a defect of the luminescent layer due to the luminescent droplet is inspected. In addition, the defect inspection method for the electroluminescence element is an observation in which a detection range subdivided from the pixel region can be observed through an irradiation step of irradiating the light emitting layer with light having a wavelength of 500 nm or less and an optical filter that transmits visible light. An observation step of observing the fluorescent light from the light emitting layer by means, and a coating amount determination step of determining the coating amount of the luminescent droplet based on the result of the observation step.
With this configuration, since the fluorescent light from the pixel region is observed in the subdivided detection range, it is possible to accurately confirm how much the light emitting droplet is applied.

According to a second aspect of the present invention, there is provided a defect inspection method for an electroluminescence element, wherein a first and second color luminescent droplets are applied to a pixel region of a substrate by a droplet application unit, and a defect of a luminescent layer caused by the luminescent droplets is applied. Inspect. In addition, the defect inspection method for the electroluminescence element is an observation in which a detection range subdivided from the pixel region can be observed through an irradiation step of irradiating the light emitting layer with light having a wavelength of 500 nm or less and an optical filter that transmits visible light. An observation step of observing fluorescent light from the light emitting layer by means, and a light emission color determination step of determining the first and second emission colors from the light emitting layer based on the result of the observation step.
With this configuration, since the fluorescent light from the pixel region is observed in the subdivided detection range, partial color mixing in the pixel region can be accurately confirmed. In addition, since an optical filter that allows visible light to pass through is provided, the influence of the irradiated light having a wavelength of 500 nm or less is small.

A defect inspection apparatus for an electroluminescence element according to a third aspect inspects a light emitting layer. This defect inspection apparatus includes a droplet application unit that applies a luminescent droplet to a pixel region between partition walls of a substrate formed by imprinting, and a wavelength of 500 nm or less on a luminescent layer formed by the luminescent droplet. Based on the result of the observation step, the observation unit that observes the fluorescent light from the light-emitting layer through an optical filter that passes through the optical filter that allows the visible light to pass through the optical filter that allows visible light to pass through And a defect location specifying part for specifying a defect location of the light emitting layer.
With this configuration, since the fluorescent light from the pixel region is observed in a subdivided detection range that is less affected by light having a wavelength of 500 nm or less irradiated by an optical filter that transmits visible light, light emission in the pixel region The defective part of the layer can be confirmed accurately.

  According to the present invention, defects in the light emitting layer of the electroluminescence element can be accurately observed on the production line in a range in which the pixel region is subdivided.

<< Organic EL Element Manufacturing Apparatus >>
In manufacturing an organic EL element, it is necessary to form a substrate on which a thin film transistor (TFT) and a pixel electrode are formed. In order to accurately form one or more organic compound layers (light-emitting element layers) including a light-emitting layer on the pixel electrode on the substrate, a partition BA (bank layer) is easily and accurately formed in the boundary region of the pixel electrode. There is a need.

  FIG. 1 is a schematic view showing a configuration of a manufacturing apparatus 100 that manufactures an organic EL element 50 having a pixel electrode and a light emitting layer on a flexible substrate.

  The manufacturing apparatus 100 for organic EL elements includes a supply roll RL for feeding out a strip-shaped flexible sheet substrate FB wound in a roll shape. For example, the length of the sheet substrate FB is 200 m or more, for example. When the supply roll RL rotates at a predetermined speed, the sheet substrate FB is sent in the X-axis direction (longitudinal direction (row direction)) that is the transport direction. The manufacturing apparatus 100 for organic EL elements includes rollers RR at a plurality of locations, and the sheet substrate FB is also sent in the X-axis direction by rotating these rollers RR. The roller RR may be a rubber roller that sandwiches the sheet substrate FB from both sides, or may be a roller RR with a ratchet as long as the sheet substrate FB has perforation.

  The manufacturing apparatus 100 for an organic EL element includes a winding roll RE that winds the sheet substrate FB into a roll in the final process. Moreover, in order to process in the repair process of a defect location, the winding roll RE winds up the sheet | seat board | substrate FB at predetermined speed so that it may synchronize with supply roll RL and roller RR.

<Partition forming process>
The sheet substrate FB sent out from the supply roll RL first enters a partition formation process for forming the partition BA on the sheet substrate FB. In the partition wall forming step, the sheet substrate FB is pressed by the imprint roller 10 and the sheet substrate FB is heated by the thermal transfer roller 15 to a glass transition point or higher so that the pressed partition wall BA maintains its shape. Therefore, the mold shape formed on the roller surface of the imprint roller 10 is transferred to the sheet substrate FB.

  The roller surface of the imprint roller 10 is mirror-finished, and a fine imprint mold 11 made of a material such as SiC or Ta is attached to the roller surface. The fine imprint mold 11 includes a thin film transistor wiring stamper and a display pixel stamper. Further, in order to form the first mark AM and the second mark BM (see FIG. 4) on both sides in the width direction of the strip-shaped flexible sheet substrate FB, the fine imprint mold 11 includes the first mark AM and the second mark. It has a BM stamper.

  Since the first marks AM and the second marks BM are formed simultaneously with the formation of the barrier ribs BA for the thin film transistors and the display pixels, the positional accuracy between the barrier ribs BA and the first marks AM and the second marks BM is: The position accuracy is the same as that of the fine imprint mold 11. That is, the fine imprint mold 11 defines the positional relationship between the first mark AM and the second mark BM and the gate bus line GBL and source bus line SBL (FIG. 2) of the thin film transistor.

  A first observation device CH <b> 1 is disposed downstream of the imprint roller 10 in the X-axis direction. The first observation device CH1 observes whether the barrier ribs BA for the thin film transistor wiring and the display pixel are accurately formed. The first observation device CH1 is configured by a camera or a laser length measuring device formed of a one-dimensional CCD or a two-dimensional CCD. A first alignment sensor CA1 is disposed downstream of the first observation device CH1.

<Electrode formation process>
After the first mark AM and the second mark BM are detected by the first alignment sensor CA1, the sheet substrate FB enters the electrode forming process when it further proceeds in the X-axis direction.
The thin film transistor (TFT) may be an inorganic semiconductor type or an organic semiconductor type. If a thin film transistor is formed using this organic semiconductor, the thin film transistor can be formed by utilizing a printing technique or a droplet coating technique.

  Of the thin film transistors using organic semiconductors, field effect transistors (FETs) are particularly preferable. In the electrode formation process of FIG. 1, the bottom gate type organic EL element 50 of FET is demonstrated. After forming the gate electrode G, the gate insulating layer I, the source electrode S, the drain electrode D, and the pixel electrode P on the sheet substrate FB, the organic semiconductor layer OS is formed.

  In the electrode forming process, a droplet applying apparatus 20 that receives position information from the first alignment sensor CA1 and applies droplets to the sheet substrate FB is used. The droplet applying device 20 can adopt an ink jet method or a dispenser method. Examples of the inkjet method include a charge control method, a pressure vibration method, an electromechanical conversion method, an electrothermal conversion method, and an electrostatic suction method. In the droplet coating method, use of the material is less wasteful, and a desired amount of material can be accurately disposed at a desired position. Hereinafter, the droplet applying device 20 for the gate electrode G is distinguished from the gate droplet applying device 20G by adding G or the like at the end. The same applies to the other droplet applying apparatuses 20. Note that the amount of one drop of the metal ink MI applied by the droplet applying method is, for example, 1 to 300 nanograms.

  The gate droplet applying apparatus 20G applies the metal ink MI into the partition wall BA of the gate bus line GBL. Then, the metal ink MI is dried or baked (baked) by hot air or radiant heat such as far infrared rays in the heat treatment apparatus BK. With these processes, the gate electrode G is formed. The metal ink MI is a liquid in which a conductor having a particle diameter of about 5 nm is stably dispersed in a solvent at room temperature, and carbon, silver (Ag), gold (Au), or the like is used as the conductor.

  A second observation device CH2 is disposed downstream of the gate droplet applying device 20G. The second observation device CH2 observes whether or not the metal bus MI is applied to the gate bus line GBL and functions as a conducting wire. The second observation device CH2 is composed of a camera composed of a one-dimensional CCD or a two-dimensional CCD. A second alignment sensor CA2 is disposed downstream of the second observation device CH2.

  Next, the droplet applying apparatus 20I for the insulating layer receives the positional information from the second alignment sensor CA2 and applies an electrically insulating ink of polyimide resin or urethane resin to the switching unit. Then, the electrically insulating ink is dried and cured by the heat treatment apparatus BK using hot air or radiant heat such as far infrared rays. With these processes, the gate insulating layer I is formed.

  A third observation device CH3 is disposed downstream of the droplet applying device 20I for the insulating layer. The third observation device CH3 observes whether or not the electrically insulating ink is applied at an accurate position. The third observation device CH3 is also composed of a camera composed of a one-dimensional CCD or a two-dimensional CCD. A third alignment sensor CA3 is disposed downstream of the third observation apparatus CH3.

  Next, the droplet applying device 20SD for the source, the drain, and the pixel electrode receives the position information from the third alignment sensor CA3 and applies the metal ink MI to the partition BA of the source bus line SBL and the partition of the pixel electrode P. Apply in BA. Then, the metal ink MI is dried or baked (baked) by the heat treatment apparatus BK. By these processes, an electrode in a state where the source electrode S, the drain electrode D, and the pixel electrode P are connected is formed.

  A fourth observation device CH4 is disposed downstream of the droplet applying device 20SD for the source, the drain, and the pixel electrode. The fourth observation device CH4 observes whether or not the metal ink MI is applied at an accurate position. The fourth observation device CH4 is also composed of a camera composed of a one-dimensional CCD or a two-dimensional CCD. A fourth alignment sensor CA4 is disposed downstream of the fourth observation apparatus CH4.

  Next, the source electrode S and the drain electrode D connected to each other are cut by the cutting device 30 in response to the positional information from the fourth alignment sensor CA4. The cutting device 30 is preferably a femtosecond laser. The femtosecond laser irradiation unit using a titanium sapphire laser irradiates a laser beam LL having a wavelength of 760 nm while swinging back and forth with a pulse of 10 KHz to 40 KHz.

  Since the cutting device 30 uses a femtosecond laser, processing on the order of submicron is possible, and the distance between the source electrode S and the drain electrode D that determines the performance of the field effect transistor is accurately cut. The distance between the source electrode S and the drain electrode D is about 20 μm to 30 μm. By this cutting process, an electrode in which the source electrode S and the drain electrode D are separated is formed. In addition to the femtosecond laser, a carbon dioxide laser, a green laser, or the like can be used. In addition to the laser, it may be mechanically cut with a dicing saw or the like.

  A fifth observation device CH5 is disposed downstream of the cutting device 30. The fifth observation device CH5 observes whether or not the distance between the source electrode S and the drain electrode D is accurately formed. The fifth observation device CH5 is also composed of a camera composed of a one-dimensional CCD or a two-dimensional CCD. A fifth alignment sensor CA5 is disposed downstream of the fifth observation apparatus CH5.

  Next, the organic semiconductor droplet applying apparatus 20OS receives the position information from the fifth alignment sensor CA5 and applies the organic semiconductor ink to the switching unit between the source electrode S and the drain electrode D. Then, the organic semiconductor ink is dried or baked by a heat treatment apparatus BK by radiant heat such as hot air or far infrared rays. With these processes, the organic semiconductor layer OS is formed.

  The compound forming the organic semiconductor ink may be a single crystal material or an amorphous material, and may be a low molecule or a polymer. Particularly preferred are single crystals or π-conjugated polymers of condensed ring aromatic hydrocarbon compounds represented by pentacene, triphenylene, anthracene and the like.

  A sixth observation device CH6 is disposed downstream of the organic semiconductor droplet coating apparatus 20OS. The sixth observation device CH6 observes whether or not the organic semiconductor ink is applied at an accurate position. The sixth observation device CH6 is also composed of a camera composed of a one-dimensional CCD or a two-dimensional CCD. A sixth alignment sensor CA6 is disposed downstream of the sixth observation apparatus CH6.

<Light emitting layer forming step>
The manufacturing apparatus 100 for an organic EL element continues the process of forming the light emitting layer IR of the organic EL element on the pixel electrode P.
In the light emitting layer forming step, the droplet applying device 20 is used. As described above, an ink jet method or a dispenser method can be adopted. Although not described in detail in the present embodiment, the light emitting layer IR can be formed by a printing roller.

  The light emitting layer IR contains a host compound and a phosphorescent compound (also referred to as a phosphorescent compound). The host compound is a compound contained in the light emitting layer. A phosphorescent compound is a compound in which light emission from an excited triplet is observed and emits phosphorescence at room temperature.

The droplet emitting device 20Re for the red light emitting layer receives position information from the sixth alignment sensor CA6, applies the R solution onto the pixel electrode P, and forms a film so as to have a thickness of 100 nm after drying. The R solution is a solution in which a red dopant material is dissolved in 1,2-dichloroethane in a host material polyvinylcarbazole (PVK).
Subsequently, the green light emitting layer droplet applying apparatus 20Gr receives position information from the sixth alignment sensor CA6 and applies the G solution onto the pixel electrode P. The G solution is a solution in which a green dopant material is dissolved in 1,2-dichloroethane in a host material PVK.

Further, the blue light emitting layer droplet applying apparatus 20BL receives position information from the sixth alignment sensor CA6 and applies the B solution onto the pixel electrode P. The solution B is a solution in which a blue dopant material is dissolved in 1,2-dichloroethane in a host material PVK.
Thereafter, the light emitting layer solution is dried and cured by a heat treatment apparatus BK by radiant heat such as hot air or far infrared rays.

  A seventh observation device CH7 is disposed downstream of the light emitting layer forming step. The seventh observation device CH7 observes whether or not the light emitting layer is appropriately formed. A seventh alignment sensor CA7 is disposed downstream of the seventh observation device CH7.

  Next, the droplet applying apparatus 20I for the insulating layer receives position information from the seventh alignment sensor CA7, so that the electrically insulating ink of polyimide resin or urethane resin does not short-circuit with the transparent electrode ITO described later. It is applied to a part of the gate bus line GBL or the source bus line SBL. Then, the electrically insulating ink is dried and cured by the heat treatment apparatus BK using hot air or radiant heat such as far infrared rays.

  An eighth observation device CH8 is arranged downstream of the droplet applying device 20I for the insulating layer. The eighth observation device CH8 observes whether or not the electrically insulating ink is applied. An eighth alignment sensor CA8 is disposed downstream of the eighth observation device CH8.

Thereafter, the droplet applying device 20IT for ITO electrode receives the positional information from the eighth alignment sensor CA8 and applies ITO (Indium Tin Oxide) ink on the red, green and blue light emitting layers. The ITO ink is a compound obtained by adding several percent of tin oxide (SnO ₂ ) to indium oxide (In ₂ O ₃ ), and its electrode is transparent. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. The transparent conductive film preferably has a transmittance of 90% or more. Then, the ITO ink is dried and cured by heat treatment or radiant heat such as far infrared rays in the heat treatment apparatus BK.

A ninth observation device CH9 is disposed downstream of the droplet applying device 20IT for the ITO electrode. The ninth observation device CH9 observes whether or not the electrically insulating ink is applied.
The organic EL element 50 may be provided with a hole transport layer and an electron transport layer, and these layers may be formed by using a printing technique or a droplet coating technique.

  The manufacturing apparatus 100 for an organic EL element has a main control unit 90. The signals observed by the first observation device CH1 to the ninth observation device CH9 and the alignment signals from the first alignment sensor CA1 to the eighth alignment sensor CA8 are sent to the main control unit 90. The main controller 90 controls the speed of the supply roll RL and the roller RR.

<< Structure of Organic EL Element 50 >>
FIG. 2 is a conceptual diagram of the organic EL element 50 manufactured by the manufacturing apparatus 100 for organic EL elements. In FIG. 2, the light emitting layer IR is formed, but before the ITO electrode is formed. As shown in FIG. 2, the organic EL element 50 is disposed in the center of the sheet substrate FB, and a signal line driving circuit 51 and a scanning driving circuit 53 are provided on the outer peripheral portion thereof. A source bus line SBL is connected to the signal line driving circuit 51, and the source bus line SBL is wired to each organic EL element 50. A gate bus line GBL is connected to the scan driving circuit 53, and the gate bus line GBL is wired to each organic EL element 50. Further, a common electrode (not shown) is also wired to the organic EL element 50.

  The peripheral part of the sheet substrate FB of the entire organic EL element 50 may have a relatively large line width as compared with the organic EL element 50. For this reason, even if the signal line driving circuit 51 and the scanning driving circuit 53 are not particularly provided with the partition BA, there is no problem even if the metal ink MI is simply applied by the droplet applying device 20.

  FIG. 3A is an enlarged view of a part of the organic EL element 50 of FIG. 2, and is a view showing a state of the bottom contact type organic EL element in which the light emitting layer IR and the ITO electrode are formed. 3B and 3C are a cross-sectional view taken along the line bb and a line cc of FIG. In the organic EL element 50, a gate electrode G, a gate insulating layer I, and a pixel electrode P are formed on a sheet substrate FB, and an organic semiconductor layer OS, a light emitting layer IR, and an ITO electrode are further formed.

  In FIG. 3, the sheet substrate FB is composed of a heat resistant resin film. Specifically, as the sheet substrate FB, polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, vinyl acetate resin, etc. Is used.

  As described above, the sheet substrate FB is subjected to heat transfer heat treatment in the partition formation process, and various inks must be dried or baked (baked) by the heat treatment apparatus BK, and thus heated to around 200 ° C. . The sheet substrate FB preferably has a smaller coefficient of thermal expansion so that the dimensions do not change even when subjected to heat. For example, an inorganic filler can be mixed with a resin film to reduce the thermal expansion coefficient. Examples of the inorganic filler include titanium oxide, zinc oxide, alumina, silicon oxide and the like.

As shown in FIGS. 3B and 3C, the presence of the partition BA makes it possible to form an accurate and uniform electrode or light emitting layer. Since the sheet substrate FB is fed in the X-axis direction (longitudinal direction) at high speed by the roller RR, even when there is a possibility that the droplet applying device 20 cannot accurately apply the droplet, an accurate and uniform electrode or light emitting layer, etc. Can be formed.
The manufacturing apparatus 100 can manufacture various field effect transistors in addition to the field effect transistor shown in FIG. For example, even a top-gate type field effect transistor can be formed by changing the order of ink applied on the sheet substrate FB.

<Details of the light emitting layer forming process>
The details of the light emitting layer forming step of the manufacturing apparatus 100 for an organic EL element will be described with reference to FIG.
In FIG. 4A, the sheet substrate FB is at least on both sides of the sheet substrate FB with respect to the thin film transistor wiring barrier BA and the pixel partition BA aligned in the Y-axis direction which is the width direction of the sheet substrate FB. One first mark AM is provided. For example, one second mark BM is formed next to the first mark AM for 50 first marks AM. Since the sheet substrate FB is as long as, for example, 200 m, the second mark BM is provided in order to make it easy to confirm at which intervals the row of the thin film transistor wiring BA and the pixel partition BA of the row. The pair of sixth alignment sensors CA6 detect the first mark AM and the second mark BM, and send the detection results to the main control unit 90.

  By detecting the pair of first marks AM, the main control unit 90 also detects a deviation in the X-axis direction, a deviation in the Y-axis direction, and θ rotation. Further, the first mark AM may be provided not only on both sides of the sheet substrate FB but also in the central region.

  The sixth alignment sensor CA6 constantly observes the sheet substrate FB sent in the X-axis direction, and sends an image of the first mark AM to the main control unit 90. The main control unit 90 includes a position counting unit 95 therein, and the position counting unit 95 is the organic EL element 50 formed on the sheet substrate FB in which number row of the organic EL elements 50 aligned in the Y-axis direction. Count if there is. Since the main controller 90 controls the rotation of the roller RR, what number of rows of the organic EL elements 50 are sent to the position of the gate droplet applying apparatus 20G, and also to the position of the seventh observation apparatus CH7. It is possible to grasp the number of rows of the organic EL elements 50 being sent.

  The position counting unit 95 confirms whether there is a mistake in counting the number of rows by the first mark AM based on the image of the second mark BM sent from the sixth alignment sensor CA6. For example, there is a defect in the location of the first mark AM of the fine imprint mold 11 and the number of rows cannot be accurately grasped.

  The droplet emitting device 20Re for the red light emitting layer, the droplet applying device 20Gr for the green light emitting layer, and the droplet applying device 20BL for the blue light emitting layer are arranged in the Y-axis direction (column direction), and are arranged in a plurality of rows. The nozzles 22 are arranged in the Y-axis direction, and a plurality of nozzles 22 are also arranged in the X-axis direction (row direction). In FIG. 4, the droplet applying device 20Gr for the green light emitting layer and the droplet applying device 20BL for the blue emitting layer are omitted, and the droplet applying device 20Re for the red emitting layer is representatively drawn. In the following description, the red light emitting layer droplet applying apparatus 20Re will be described as a representative.

  The droplet emitting device 20Re for the red light emitting layer switches the timing for applying the R solution from the nozzle 22 and the nozzle 22 for applying the R solution in accordance with the position signal from the main control unit 90 based on the sixth alignment sensor CA6. .

  A heat treatment apparatus BK is disposed downstream of the red light emitting layer droplet applying apparatus 20Re, and the heat treatment apparatus BK dries the R solution applied by the red light emitting layer droplet applying apparatus 20Re. A seventh observation apparatus CH7 is disposed downstream of the heat treatment apparatus BK.

  The seventh observation device CH7 sends the observed image signal to the main control unit 90. In the main control unit 90, the region where the red light emitting layer droplet applying device 20Re must apply the R solution and the observed image signal are sent. By comparing, the defective part of application | coating of R solution is pinpointed. With respect to the Y-axis direction, the position of the organic EL element 50 in what column or the position away from the first mark AM by the image processing is specified by the image processing. Based on the position counting unit 95, the position of the organic EL element 50 in the row and the position in the organic EL element 50 in the row are specified based on the position counting unit 95.

  The first mark AM and the second mark BM are composed of a diffraction grating GT. The first mark AM is a dot-like diffraction grating GT arranged in the X-axis direction and the Y-axis direction as shown in the upper part of FIG. The cross section of the dot-like diffraction grating GT has the shape shown in the lower part of FIG. Although not shown for the second mark BM, the second mark BM is also a dot-like diffraction grating GT similar to the first mark AM.

  FIG. 4C shows an alignment sensor CA that detects the first mark AM or the second mark BM. In order to detect the first mark AM or the second mark BM, the first mark AM or the second mark BM is irradiated with coherent light such as He—Ne laser light (λ = 0.6328 μm). Then, ± n-order images (n = 1, 2,...) From the dot-like diffraction grating GT are detected via the lens LEN.

  When the interval between the dot-shaped diffraction gratings GT, that is, the lattice constant is L, the wavelength of the coherent light is λ, and the angle between the irradiation angle of the coherent light and the alignment sensor CA is θ, Lsinθ = nλ (n = ± 1, ± 2,...)

  As shown in the graph shown in FIG. 4C, the alignment sensor CA detects a waveform signal at a location where the dot-like diffraction grating GT exists, and does not detect a signal where there is no diffraction grating. For this reason, the position counting unit 95 digitizes the detected signal to determine which row of the organic EL elements 50 arranged in the Y-axis direction among the organic EL elements 50 on which the sheet substrate FB is formed. Count. Therefore, the position of the organic EL element 50 can be grasped quickly and accurately. Further, since the first mark AM or the second mark BM is a diffraction grating, it is hardly affected by dirt or the like.

<Seventh Observation Device CH7 for Light-Emitting Layer IR>
FIG. 5 is a perspective view from the sixth alignment sensor CA6 to the seventh observation device CH7. The repair location is basically the same in other processes. In FIG. 5, the droplet emitting device 20Gr for the green light emitting layer and the droplet applying device 20BL for the blue light emitting layer are omitted, and the droplet applying device 20Re for the red light emitting layer is representatively drawn.

  The main control unit 90 includes a position counting unit 95 that counts the position in the X-axis direction, a repaired part specifying unit 96 that specifies a defective part, that is, a repaired part that must be repaired, and design dimensions and repair of the organic EL element 50 A storage unit 97 for storing locations and the like is included. The repair location identification unit 96 includes an application amount determination unit 961, an emission color determination unit 962, and an application position determination unit 963.

  The sixth alignment sensor CA6 is connected to the main control unit 90, and the sixth alignment sensor CA6 sends an image signal of the first mark AM to the main control unit 90. The main control unit 90 measures the position and inclination of the sheet substrate FB in the Y-axis direction based on the image signal, and measures the first mark AM on both sides of the sheet substrate FB to thereby measure the Y-axis direction of the sheet substrate FB. Also measure the elongation.

  Since the main controller 90 also controls the rotation of the roller RR, the main controller 90 can grasp the moving speed in the X-axis direction of the sheet substrate FB, and the R solution is applied to the red light emitting layer droplet applying apparatus 20Re based on the first mark AM. A signal is output so as to apply. The droplet applying device 20Re applies the R solution to the pixel electrode P of each organic EL element 50. Thereafter, the heat treatment apparatus BK dries the applied R solution.

  The seventh observation apparatus CH7 includes a short wavelength light source UV, a lens LEN, a one-dimensional CCD, and the like inside, and an image signal of the one-dimensional CCD is sent to the main control unit 90. The short wavelength light source UV emits blue light or ultraviolet light having a wavelength of 500 nm. When the light emitting layer IR is irradiated with such short wavelength light, the light emitting layer IR is excited and emits fluorescent light or phosphorescent light (hereinafter referred to as fluorescent light including phosphorescent light). The one-dimensional CCD outputs this fluorescent light as an image signal.

  The application amount determination unit 961 applies the R applied by the droplet applying device 20Re based on the partial region where the fluorescent light is emitted (the data (Dn (m, n)) of the matrix MAT for k rows and h columns). Know the amount of solution applied. The application position determination unit 963 grasps the application position of the R solution applied by the droplet applying apparatus 20Re based on the partial region where the fluorescent light is emitted. The repair location specifying unit 96 compares the design value stored in the storage unit 97, that is, the area or position of the pixel electrode P with the area or position of the R solution actually applied by the droplet applying device 20Re, and is different. The location is identified as a defective location. The partial region (data of matrix MAT (Dn (m, n)) for k rows and h columns) will be described later.

  If the image signal from the one-dimensional CCD is color, the emission color determination unit 962 grasps whether the correct emission color is applied to the pixel electrode P based on the partial area where the fluorescent light is emitted. Can do. When the light emitting layer IR is not irradiated with the short wavelength light from the short wavelength light source UV, the light emitting layer IR is monochromatic and cannot distinguish between blue, green and red. The repair location specifying unit 96 compares the emission color, which is a design value stored in the storage unit 97, with the color actually applied by the droplet applying apparatus 20Re, and specifies a different location as a defective location.

  In addition, the repair location specifying unit 96 can specify the distance (μm) in the X-axis direction and the Y-axis direction with respect to the first mark AM where the application amount, application position, or emission color defect location is. Also, the organic EL element 50 in which row is identified by the count of the position control unit 95 is also specified. The identified repair location is stored in the storage unit 97, and the data of the repair location is used in the repair process.

FIG. 6A shows an organic EL element 50 observed by the seventh observation apparatus CH7 and a matrix MAT displayed so as to overlap therewith.
The one-dimensional CCD of the seventh observation apparatus CH7 can output image data for each pixel pitch in the Y-axis direction, and adjusts the sampling time because the sheet substrate FB moves at a constant speed in the X-axis direction. Thus, it is possible to output image data in the X-axis direction of the sheet substrate FB at every predetermined pitch. That is, image data of a partial area subdivided with respect to the organic EL element 50 can be obtained. This image data is stored in the storage unit 97 as a matrix MAT.

  As shown in FIG. 6A, since the first mark AM is formed on the sheet substrate FB, the image data of the subdivided partial area is associated with position information in the X-axis direction and the Y-axis direction. Note that the size of the partial area to be subdivided can be changed by changing the pixel pitch of the one-dimensional CCD of the seventh observation apparatus CH7 shown in FIG. 5 and the magnification of the lens LEN.

  FIG. 6B is a diagram showing the subdivided partial areas stored in the storage unit 97 as a matrix MAT. The subdivided partial area is stored in the storage unit 97 as matrix MAT data (Dn (m, n)) for k rows and h columns together with the position information of the area. However, it is not necessary to define the matrix MAX for k rows and h columns in accordance with the pixel pitch of the one-dimensional CCD. Since the main purpose of the seventh observation device CH7 is to observe the light emitting layer IR of the pixel electrode P, one matrix may be formed for each pixel of the organic EL element 50 and stored in the storage unit 97.

<Configuration of Seventh Observation Device CH7>
FIG. 7A is a first example of the seventh observation apparatus CH7, and FIG. 7B is a second example of the seventh observation apparatus CH7. In both figures, the same reference numerals are assigned to the same components.

  FIG. 7A shows a first example of the seventh observation apparatus CH7. Specifically, FIG. 7A is a schematic diagram of an observation apparatus using photoluminescence that irradiates short wavelength light and obtains fluorescent light from the light emitting layer IR. The short wavelength light irradiated from the short wavelength light source UV enters the beam splitter BS via the ultraviolet light region filter F1. As the short wavelength light source UV, a UV-LED, a mercury lamp, a YAG laser, or the like can be used. By using the ultraviolet light region filter FI, the wavelength in the visible light region generated from the short wavelength light source UV can be excluded. The short wavelength light is reflected by the beam splitter BS, passes through the lens LEN, and travels toward the light emitting layer IR of the organic EL element 50. The lens LEN collects short wavelength light on the light emitting layer IR.

  In particular, the short wavelength light source UV preferably uses a high frequency of a YAG laser. The fundamental wave of the YAG laser is 1064 nm, and its emission layer IR is irradiated with its third harmonic (THG) of 355 nm and its fourth harmonic (FHG) of 266 nm. The third harmonic or the fourth harmonic of the fundamental wave of the YAG laser has a higher luminance per unit area than a light source such as a mercury lamp. For this reason, when the light emitting layer IR is irradiated with the third harmonic or the fourth harmonic of the fundamental wave of the YAG laser, brighter fluorescent light can be observed.

  Part of the fluorescent light excited by irradiating the light emitting layer IR with the short wavelength light passes through the lens LEN and travels toward the beam splitter BS. The fluorescent light passes through the beam splitter BS and enters the one-dimensional CCD through the visible light region filter F2. The visible light region filter F2 is used to reduce the influence of short wavelength light. The one-dimensional CCD is a color sensor, and a partial area corresponding to h columns in the Y-axis direction (column direction) shown in FIG. 6 can be observed.

  Since the moving speed of the sheet substrate FB is fast or there is little fluorescent light, noise may increase in the image signal of the data (Dn (m, n)) in the column direction of the matrix MAT. In this case, a two-dimensional CCD connected with a frame storage type memory that shifts the CCD storage location in accordance with the moving speed of the sheet substrate FB may be prepared. This method is a kind of CCD readout method generally called TDI (Time Delayed Integration) method.

FIG. 7B shows a second example of the seventh observation apparatus CH7. Only the configuration different from the first example will be described.
Part of the fluorescent light excited by irradiating the light emitting layer IR with the short wavelength light passes through the lens LEN and travels toward the beam splitter BS. The fluorescent light passes through the beam splitter BS, and only the red visible light is reflected by the first dichroic mirror DM1 and travels toward the red one-dimensional CCD-Re. The visible light that has passed through the first dichroic mirror DM1 is reflected only by the second dichroic mirror DM2, and the green visible light is incident on the green one-dimensional CCD-Gr. The blue visible light that has passed through the second dichroic mirror DM2 enters the blue one-dimensional CCD-BL. A visible light region filter F2 may be disposed between the beam splitter BS and the first dichroic mirror DM1.

FIG. 8 is a flowchart in the step of forming the light emitting layer IR of FIG. 5 and the step of storing the repaired portion.
In step P11, the alignment sensor CA5 captures the first mark AM and sends an image signal to the main controller 90.
In Step P12, the main control unit 90 calculates the position of the first mark AM, and the position counting unit 95 counts the number of rows of the organic EL elements 50. The first mark AM is used by the cutting device 30 for positioning the source electrode S and the drain electrode D and also for specifying the number of rows of the organic EL elements 50. Note that the number of rows of the organic EL elements 50 may be specified by photographing the second mark BM described in FIG. 4 with the sixth alignment sensor CA6.

  In Step P13, based on the position of the first mark AM and the position of the pixel electrode P stored in the storage unit 97, the RBG solution is applied from the coating by the droplet coating apparatuses 20Re, 20Gr, and 20BL for the light emitting layer. The pixel electrode P is applied. Thereafter, the RBG solution for the light emitting layer is dried and cured by hot air or radiant heat such as far infrared rays in the heat treatment apparatus BK.

  In Step P <b> 14, the seventh observation device CH <b> 7 irradiates the light emitting layer IR with the short wavelength light, thereby sending the image signal of the fluorescent light from the light emitting layer IR to the repair location specifying unit 96.

Next, in Step P15, the application amount determination unit 961 compares the pixel area stored in the storage unit 97 with the image signal of the actual applied area to identify a defective portion. If the data (Dn (m, n)) of the matrix MAT for k rows and h columns shown in FIG. 6 is used, the coating area can be grasped.
In Step P <b> 16, the light emission color determination unit 962 compares the light emission color stored in the storage unit 97 with the actual color signal to identify a defective portion.

Next, in Step P <b> 17, the application position determination unit 963 compares the application position stored in the storage unit 97 with the image signal of the actual application position, and specifies a defective portion. Since the position can also be grasped by using the data (Dn (m, n)) of the matrix MAT for k rows and h columns, the application amount determination unit 961 may also function as the application position determination unit 963.
In Step P18, the defective part is stored in the storage unit 97 as the repaired part to be repaired as the number of rows and the distance from the position of the first mark AM.

  FIG. 9 identifies the defect area based on the data Dn (m, n) of the matrix MAX and can the defect be dealt with by repair or is the maintenance of the production line of the production apparatus 100 of FIG. 1 stopped? It is a defect determination flowchart which determines.

In step P31, data Dn (m, n) of the matrix MAT for k rows and h columns is set. In this flowchart, it is assumed that data Dn (m, n) as shown in FIG. 6A is allocated to the light emitting layer of the organic EL element 50.
In Step P32, the seventh observation apparatus CH7 irradiates the short wavelength light source UV and observes the light emitting layer IR of the organic EL element 50. As a result, the data Dn (m, n) of the matrix MAT is sent to the repair location specifying unit 96.

  In step P33, the application amount determination unit 961 (see FIG. 5) in the repair location specifying unit 96 determines that the partial region of Dn (m, n) is based on the design data stored in advance in the storage unit 97. It is determined whether or not it is a coated partial area. If the RGB solution is not applied even though it is a partial region to be applied, it is determined as a defective portion and the process proceeds to Step P36.

  In step P34, the emission color determination unit 962 determines whether the data Dn (m, n) is red, green, or blue based on the design data stored in the storage unit 97 in advance. Determine whether or not. If the partial area that should originally be blue is red, if it is determined as each prefecture location, the process proceeds to step P36.

In Step P35, it is determined that there is no defect in the light emitting layer IR on the pixel electrode P.
In step P36, the number of the defect areas is counted, and the number of defect portions in the square area sandwiched between (m−r, n−r) and (m + r, n + r), that is, the defect density is calculated. Note that a rectangular region may be used instead of the square region.
In Step P37, it is determined whether or not the number of defect locations in the square area, that is, the defect density is equal to or greater than a threshold value. If the defect density is higher than the threshold value, it is determined that repairs cannot be performed because there are too many defective parts, so the process proceeds to step P39 and the line of the manufacturing apparatus 100 is stopped. And maintenance of the manufacturing apparatus 100 shown in FIG. 1 is performed. If the defect density is lower than the threshold, the process proceeds to Step P38 so that the defect is repaired.

In step P38, the defective area is repaired by a repair line (not shown). If the defect density is lower than the threshold value, it means that the defect area is dispersed. Therefore, even if repairs are made, the repair area is inconspicuous. The data (Dn (m, n)) stored together with the position information in the storage unit 97 is sent to the repair line.
In Step P39, the line of the manufacturing apparatus 100 is stopped, and maintenance work is performed so that no further defective portion occurs.

In the above embodiments, the three-color method for forming the R, G, and B organic EL elements 50 has been described. However, the white method for combining the white EL and the color filter, the CCM method for combining the blue EL, the ultraviolet EL, and the color conversion material. Also effective.
In the white method, a white EL is irradiated with ultraviolet light, and a plurality of generated fluorescence is separated by an optical filter and observed to observe the color balance. Further, fluorescence may be observed by the same method after forming the color filter. In the CCM method, in addition to the method of observing fluorescence from the EL layer, it is possible to observe the color balance by performing the same observation after forming the color conversion element. Further, when the fluorescence color due to ultraviolet light is shifted in RGB shown in the chromaticity diagram due to the properties of the material, it is desirable to match the transmittance characteristics of the optical filter in accordance with the wavelength.

  Further, although the heat treatment apparatus BK is provided in the manufacturing apparatus 100 of the embodiment, an ink or a solution that does not require heat treatment has been proposed by improving the light emitting layer solution or the like. For this reason, it is not always necessary to provide the heat treatment apparatus BK in this embodiment.

It is the schematic which showed the structure of the manufacturing apparatus 100 which manufactures an organic EL element on the flexible board | substrate FB. It is a conceptual diagram of the organic EL element 50 manufactured with the manufacturing apparatus 100 for organic EL elements. FIG. 3 is an enlarged view of a part of the organic EL element 50 in FIG. 2 and shows a state of a bottom contact type organic EL element in which a light emitting layer IR and an ITO electrode are formed. It is a conceptual diagram which observes the 1st mark AM and 2nd mark BM of a diffraction grating at the electrode formation process of the manufacturing apparatus 100 for organic EL elements. It is a perspective view from 6th alignment sensor CA6 to 7th observation apparatus CH7. The organic EL element 50 observed with the seventh observation device CH7 and the matrix MAT obtained with the seventh observation device CH7 are shown. It is a 1st example of 7th observation apparatus CH7, and is a schematic diagram of the observation apparatus using the photoluminescence which irradiates short wavelength light and obtains the fluorescence light from light emitting layer IR. It is a 2nd example of 7th observation apparatus CH7, and is a schematic diagram of the observation apparatus using the photoluminescence which irradiates short wavelength light and obtains the fluorescence light from light emitting layer IR. It is a flowchart in the process of memorize | storing the formation process of the light emitting layer IR of FIG. 5, and its repair location. It is a flowchart which determines whether a defective part can be repaired or it is necessary to maintain a manufacturing line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Imprint roller 11 Fine imprint mold 15 Thermal transfer roller 20 Droplet coating device (20BL: Droplet coating device for blue light emitting layer, 20G ... Droplet coating device for gate, 20Gr ... Droplet coating for green light emitting layer Apparatus, 20I: droplet coating apparatus for insulating layer, 20Re: droplet coating apparatus for red light emitting layer, 20IT: droplet coating apparatus for ITO electrode, 20OS ... organic semiconductor droplet coating apparatus, 20SD: for source and (Droplet and pixel electrode droplet applicator)
22 Nozzle 30 Cutting device 50 Organic EL element 90 Main control unit 95 Position counting unit 96 Repair location specifying unit (961 ... coating amount determination unit, 962 ... emission color determination unit, 963 ... application position determination unit)
97 Storage Unit 190 Repair Main Control Unit 100 Organic EL Element Manufacturing Apparatus AM First Mark (Alignment Mark)
BA Bulkhead BK Heat treatment apparatus BS Beam splitter CA Alignment sensor CCD Charge coupled device D Drain electrodes F1, F2 Ultraviolet light filter, visible light filter FB Sheet substrate G Gate electrode GBL Gate bus line I Gate insulating layer IR Light emitting layer ITO Transparent Electrode LAM Illumination light source LEN Lens LL Laser light OS Organic semiconductor layer P Pixel electrode RL Supply roll RR Roller S Source electrode SBL Source bus line UV Short wavelength light source

Claims (14)

In a defect inspection method for an electroluminescent element, in which a luminescent droplet is applied to a pixel region of a substrate by a droplet application unit, and a defect of the luminescent layer due to the luminescent droplet is inspected,
An irradiation step of irradiating the light emitting layer with light having a wavelength of 500 nm or less;
An observation step of observing fluorescent light from the light emitting layer with an observation means capable of observing a detection range subdivided from the pixel region through an optical filter that allows visible light to pass;
A coating amount determination step of determining a coating amount of the luminescent droplet based on the result of the observation step;
A defect inspection method for an electroluminescence element. In the defect inspection method of the electroluminescence element, the first and second color luminescent droplets are applied to the pixel region of the substrate by the droplet application unit, and the defect of the luminescent layer due to the luminescent droplets is inspected.
An irradiation step of irradiating the light emitting layer with light having a wavelength of 500 nm or less;
An observation step of observing fluorescent light from the light emitting layer with an observation means capable of observing a detection range subdivided from the pixel region through an optical filter that allows visible light to pass;
An emission color determination step of determining the emission colors of the first color and the second color from the emission layer based on the result of the observation step;
A defect inspection method for an electroluminescence element.   3. The defect inspection method for an electroluminescent element according to claim 1, further comprising a position determination step for determining a position where the light emitting layer is formed based on a result of the observation step.   4. The optical filter that allows only visible light wavelength to pass is disposed between the observation unit and the light emitting layer in the observation step. 5. The defect inspection method of the electroluminescent element of description. The observation means is a one-dimensional sensor extending in a column direction, and the substrate is a flexible substrate sent at a predetermined speed in a row direction,
In the observing step, the column direction of the pixel region is observed by the one-dimensional sensor, and an output of the one-dimensional sensor is sequentially updated according to a predetermined speed at which the flexible substrate is sent, so that a matrix is obtained. 5. The defect inspection method for an electroluminescent element according to claim 1, wherein the fluorescent light divided into two types is observed. The observation means is a two-dimensional sensor connected to a frame storage type memory, and the substrate is a flexible substrate sent at a predetermined speed in the row direction,
In the observation step, the column direction of the pixel region is observed by the two-dimensional sensor, and the accumulation location of the two-dimensional sensor is shifted according to a predetermined speed at which the flexible substrate is sent, The defect inspection method for an electroluminescence element according to claim 1, wherein the fluorescent light divided into a matrix is observed.   2. The defect inspection method for an electroluminescent element according to claim 1, wherein the application amount of the luminescent droplets by the droplet application unit is adjusted by the determination in the application amount determination step.   The defect inspection of the electroluminescent element according to claim 1, wherein the light emitting layer is repaired or the production line including the droplet application part is stopped by the determination in the application amount determination step. Method. In a defect inspection apparatus for inspecting a defect in a light emitting layer of an electroluminescence element,
A droplet application unit that applies luminescent droplets to a pixel region between the partition walls of the substrate formed by imprinting;
An irradiating unit that irradiates light having a wavelength of 500 nm or less to the light emitting layer formed of the light emitting droplets;
An observation means that can observe a detection range subdivided from the pixel region, and observes the fluorescent light from the light emitting layer through an optical filter that allows visible light to pass through.
Based on the result of the observation step, a defect location identifying unit that identifies a defect location of the light emitting layer,
A defect inspection apparatus for an electroluminescence element, comprising:   The defect inspection apparatus for an electroluminescent element according to claim 9, wherein the defect location specifying unit determines whether or not an application amount of the luminescent droplet is appropriate.   The defect inspection apparatus for an electroluminescent element according to claim 9, wherein the defect location specifying unit determines whether or not an emission color of the light emitting layer is appropriate. The observation means is a one-dimensional sensor extending in the column direction, and the substrate formed by the imprint is a flexible substrate that is fed at a predetermined speed in the row direction,
The observation means observes the column direction of the pixel region with the one-dimensional sensor, and sequentially updates the output of the one-dimensional sensor according to a predetermined speed at which the flexible substrate is sent, so that the matrix The defect inspection apparatus for an electroluminescent element according to claim 9, wherein the fluorescent light divided into two types is observed. The observation means is a two-dimensional sensor connected to a frame storage type memory, and the substrate formed by the imprint is a flexible substrate that is sent at a predetermined speed in the row direction,
The observing means is configured such that the column direction of the pixel region is observed by the two-dimensional sensor, and the accumulation position of the two-dimensional sensor is shifted according to a predetermined speed at which the flexible substrate is sent. The defect inspection apparatus for an electroluminescence element according to claim 9, wherein the fluorescent light divided into a matrix is observed.   14. The defect inspection apparatus for an electroluminescent element according to claim 9, wherein the irradiation unit irradiates a third harmonic or a fourth harmonic of a YAG laser.