JP2005142121A - Organic el display device and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device which improves productivity, and to provide a manufacturing method of the same with improved productivity. <P>SOLUTION: The manufacturing method of the organic EL display device includes a process of forming a conductive film on a flat surface of a first temporary substrate 1, a process of forming an electronic circuit by forming a laminate composed of various layers having different conductivity from each other formed by patterning the conductive film as a positive electrode of a light-emitting element, a process of sticking a second temporary substrate on the surface of the laminate, a process of removing the first temporary substrate, and a process of sticking a first flexible substrate on the surface of the laminate, at a side where the first temporary substrate is removed. A plurality of holes are formed substantially evenly on the surface of the first temporary substrate, and a release agent is applied at least on the surface, on which the conductive film is to be formed so as to cover the holes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic EL display device and a manufacturing method thereof.

  The organic EL display device is surrounded by a gate signal line extending in the x direction and juxtaposed in the y direction and a drain signal line extending in the y direction and juxtaposed in the x direction on one surface of the substrate. A light emitting layer (a thin film transistor that is turned on by a scanning signal line from a gate signal line and a current corresponding to a video signal from a drain signal line supplied via the thin film transistor) At least an organic EL layer).

  In addition, since the characteristics of the light emitting layer deteriorate due to oxidation or moisture, the light emitting layer is usually provided with another substrate different from the substrate, and a substrate for shielding the light emitting layer from the outside air.

  In addition, some of these substrates are made of, for example, a glass substrate. However, for example, those made of a resin have been known, and the organic EL display device itself has become flexible (Patent Documents 1 and 2). Non-Patent Document 1).

  In the manufacturing method, so-called transfer is repeatedly used. As disclosed in Non-Patent Document 1, for example, a conductor layer or semiconductor layer in which an electronic circuit including a thin film transistor or the like is patterned on a glass substrate. The substrate is formed of a laminate such as an insulator layer, the substrate is temporarily glued to the surface, and the glass substrate is dissolved and removed with a hydrofluoric acid solution. Thereafter, a technique is known in which the laminate is attached to a plastic substrate, the substrate is peeled off, and the laminate is copied onto the plastic substrate.

Japanese Patent Laid-Open No. 10-125931 JP 2000-44445 A SID (Society of imformation Display) 2002 Digest, pages 1196-1199

  However, the organic EL display device configured as described above requires a process such as completely melting a glass substrate, which is a relatively thick temporary substrate, in the manufacture thereof, and the time required for this is long and the productivity is high. It was still low.

  Further, in the manufacturing process, the surface must be processed while repeating the transfer. However, for example, a transfer for bringing the terminal to the surface is also required, and it has been desired to reduce the number of times of the transfer as a whole. This is because if the number of transfers is large, damage due to external obstacles such as a thin film transistor already formed and a wiring layer connected to the thin film transistor increases accordingly.

  Furthermore, a conductor layer, a semiconductor layer, an insulator layer, etc., in which an electronic circuit is patterned on a temporary substrate are formed, but when the temporary substrate is dissolved in a later step, the etching solution of the electronic circuit In order to avoid erosion, it has been necessary to consider that the etching stopper layer provided must be formed relatively thick.

  The present invention has been made based on such circumstances, and an object thereof is to provide a method of manufacturing an organic EL display device having good productivity.

  Another object of the present invention is to provide a method for manufacturing an organic EL display device in which a so-called transfer process is reduced.

  Furthermore, the objective of this invention is providing the manufacturing method of the organic electroluminescence display which can form an etching stopper layer thinly.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) Manufacturing method of organic EL display device (I)
The manufacturing method (I) of the organic EL display device includes a step of forming a conductive film on a surface of a first temporary substrate, patterning the conductive film as an anode of a light emitting element, and then forming the first temporary substrate on the first temporary substrate. Sequentially forming another conductive film having a conductivity different from that of the conductive film on the surface to form an electronic circuit including a laminate including the patterned conductive film and the other conductive film; A step of attaching a second temporary substrate to a first surface of the body opposite to the first temporary substrate, a step of removing the first temporary substrate from the laminate, and the first of the laminate. Attaching the first flexible substrate to the second surface exposed by removing the temporary substrate, and removing the second temporary substrate from the first surface of the laminate, and then attaching the first flexible substrate to the first surface. And 2 affixing the flexible substrate.

  The first temporary substrate used in the manufacturing method (I) of the organic EL display device has a plurality of holes formed on the surface thereof, and at least the surface on which the conductive film is formed is a release agent including the plurality of holes. Covered. The release agent is defined as, for example, a material that is soluble in a solvent, and the base material of the first temporary substrate is less soluble in the solvent than the material. A flexible film or sheet may be used as the first flexible substrate and the second flexible substrate.

  In the manufacturing method (I) of the organic EL display device, the surface of the release agent that covers the surface on which the conductive film of the first temporary substrate is formed may be processed flat.

  In the manufacturing method (I) of the organic EL display device, the first flexible substrate is attached to the second surface of the multilayer body and the second temporary substrate is removed from the first surface of the multilayer body. Thereafter, an organic material film including at least a light emitting layer on the first surface of the laminate and a cathode of the light emitting element overlapping the organic material film are formed, respectively, and after the formation of the cathode, the second material is formed. A flexible substrate may be attached to the first surface side of the laminate so as to cover at least the organic material film. In addition to the light emitting layer, the organic material film may be formed by laminating at least one of a hole transport layer, an electron transport layer, and an electron injection layer on the light emitting layer on the cathode of the light emitting element. . For example, the organic material film is formed by stacking an electron injection layer, an electron transport layer, a light emitting layer, and a hole transport layer in this order on the cathode, and an anode is formed on the hole transport layer.

  The plurality of holes formed in the first temporary substrate are uniformly distributed on the surface of the first temporary substrate, for example.

(2) Manufacturing method of organic EL display device (II)
The method (II) for manufacturing an organic EL display device includes a step of forming a transparent conductive film on a flat surface of a temporary substrate, patterning the transparent conductive film as an anode of a light emitting element, and then forming the flat surface of the temporary substrate. A step of forming an electronic circuit by a laminate including the patterned transparent conductive film on the surface and another conductive film having a different conductivity from the patterned transparent conductive film; and a surface of the laminate opposite to the temporary substrate A step of attaching the first flexible substrate to the substrate, a step of removing the temporary substrate from the surface of the laminate on which the transparent conductive film is formed, and a surface of the laminate on which the transparent conductive film is formed. And attaching the flexible substrate. A plurality of holes are formed on the surface of the temporary substrate, and at least a surface in contact with the laminate is covered with a release agent including the plurality of holes.

(3) Manufacturing method of organic EL display device (III)
In the method (III) for manufacturing an organic EL display device, a temporary substrate having a plurality of holes formed and covered with a release agent including the plurality of holes is prepared, and a transparent conductive material is formed on the surface of the release agent covering the temporary substrate. A step of forming a film pattern, a step of covering the transparent conductive film with an insulating material film that is less soluble in a liquid that removes the release agent than the release agent, and the transparent conductive film on the insulating material film. A step of forming another conductive film having a different conductivity to form a laminated body of an electronic circuit using the transparent conductive film as an anode of a light emitting element, and a surface of the laminated body on which the other conductive film is disposed Attaching the first flexible substrate to the substrate, removing the release agent from the liquid and removing the temporary substrate from the surface on which the transparent conductive film of the laminate is formed, and the transparent of the laminate. A second flexible substrate is placed on the surface on which the electrode film is formed. And a step to put Ri.

  In any of these manufacturing methods (II) and (III) of the organic EL display device, the surface of the release agent that covers the temporary substrate and on which the pattern of the transparent conductive film is formed may be processed flat.

  In both of the manufacturing methods (II) and (III) of these organic EL display devices, the step of attaching the first flexible substrate to the laminate, and the second flexible substrate to the laminate. A step of forming an organic material film including at least a light emitting layer on the transparent conductive film of the stacked body and a cathode of the light emitting element overlapping with the organic material film may be included between the steps.

  In any of the manufacturing methods (II) and (III) of these organic EL display devices, the organic material film is used as at least one of a hole transport layer, an electron transport layer, and an electron injection layer. You may form by laminating | stacking on the said light emitting layer above.

  The plurality of holes formed in the temporary substrate may be uniformly distributed on the surface of the temporary substrate.

(4) Organic EL display device (I)
The organic EL display device (I) includes an insulating layer having a first main surface and a second main surface facing the first main surface, a plurality of first conductive films formed on the first main surface of the insulating layer, A light-emitting element formed by sequentially laminating an organic material layer including a light-emitting layer and an electrode layer on at least one of the plurality of first conductive films; and the insulating layer formed on the second main surface of the insulating layer A laminated structure including a plurality of second conductive films electrically connected to the plurality of first conductive films through
A first flexible substrate in contact with the first main surface side of the insulating layer of the laminated structure; and
A second flexible substrate in contact with the second main surface side of the insulating layer of the laminated structure;
A portion of each of the plurality of first conductive films is exposed from the first main surface of the insulating layer, and a portion other than the portion is embedded in the insulating layer.

  Each of the plurality of first conductive films is exposed, for example, from the first main surface of the insulating layer while being embedded in the insulating layer. This insulating layer is less likely to be etched than silicon oxide, and may be formed of a material such as silicon nitride, tantalum oxide, or aluminum oxide. The insulating layer may be formed of a material that is difficult to dissolve in a silicon oxide etchant.

  In the organic EL display device (I), the light emitting element formed by laminating the organic material layer and the electrode layer on the at least one of the plurality of first conductive films is covered with the first flexible substrate. Good.

  In the organic EL display device (I), at least one of the plurality of first conductive films different from the at least one may be exposed from the first flexible substrate. At least another of the plurality of first conductive films formed in this way is used as a terminal for supplying a signal or power from the outside to the electronic circuit, for example. It is done. The surface of the at least one first conductive film exposed from the first flexible substrate is flush with the first main surface of the insulating layer exposed from the first flexible substrate adjacent thereto ( flushed with the first principal surface of the insulating layer exposed from the first flexible board).

  In the organic EL display device (I), at least one of the plurality of second conductive films connected to the at least one of the plurality of first conductive films through the insulating layer on the second main surface of the insulating layer. An electronic circuit including one may be formed, and the electronic circuit may be covered with the second flexible substrate.

  A group including the at least one of the plurality of first conductive films is two-dimensionally arranged on the first main surface of the insulating layer of the organic EL display device (I), and the plurality of first conductive films The organic material layer including the light emitting layer and the electrode layer may be sequentially stacked on each group of films to form a display screen including a plurality of the light emitting elements. At this time, the surface of the group of first conductive films exposed from the first main surface of the insulating layer may be flush with the first main surface.

(5) Organic EL display device (II)
The organic EL display device (II) includes at least one first electrode layer, the light emitting element including the first electrode layer, an organic material layer sequentially stacked on the first surface, and a second electrode layer, and the first electrode layer. A laminate having an electrode layer and an electronic circuit including a conductive layer laminated on the second surface side facing the first surface; and a pair of sandwiching the laminate from the light emitting element side and the electronic circuit side Equipped with a flexible substrate,
The organic material layer includes a light emitting layer,
The boundary surface including the first surface of the at least one first electrode layer of the stacked body also includes a surface on the light emitting element side of an insulating layer in contact with the second surface of the at least one first electrode layer.

  A third electrode layer electrically connected to at least one of the conductive layers constituting the electronic circuit through the insulating layer may be provided on the light emitting element side of the insulating layer of the organic EL display device (II). . The surface of the third electrode layer on the light emitting element side is exposed from, for example, one of the pair of flexible substrates included in the boundary surface of the multilayer body and covering the light emitting element. This third electrode layer is used as, for example, a terminal for supplying a signal or power from the outside to the electronic circuit.

  In the organic EL display device (II), a plurality of the first electrode layers are two-dimensionally arranged apart from each other by the insulating layer, and the organic material layer is formed on the first surface of each of the first electrode layers. In addition, the second electrode layer may be laminated in this order to form a display screen having a plurality of the light emitting elements. Each of these first electrode layers may be electrically connected to one of the corresponding conductive films (included in the electronic circuit) through the insulating layer. The first surface of each of the first electrode layers may be included in the boundary surface of the stacked body.

  In addition, this invention is not limited to the above structure, A various change is possible in the range which does not deviate from the technical idea of this invention.

  In the method of manufacturing an organic EL display device configured as described above, a plurality of holes are formed almost uniformly on the surface as a temporary substrate for forming a laminated body composed of various layers having different electrical conductivity constituting an electronic circuit. The release agent is formed so as to cover each hole on at least the surface on which the laminate is formed.

  For this reason, when the temporary substrate is removed after the formation of the laminate, it is only necessary to dissolve the release agent, and the dissolution agent for that purpose is made through the holes provided in the temporary substrate. Is rapidly dissolved, and productivity can be greatly improved.

  In addition, since the release agent is rapidly dissolved in this way, it can function sufficiently even if the etching stopper layer provided to avoid the erosion of the solution to the laminate is formed relatively thin. Can be made.

  Then, by pulling out a terminal from which a signal line or the like formed in the laminated body is drawn out to the surface side to be brought into contact with the temporary substrate, it is possible to eliminate the need for transfer for that purpose.

  Further, the surface of the laminate on the side from which the temporary substrate is removed is flattened in a state in which the electrodes and the like formed on the surface are embedded in an insulating film or the like. In the formation process, for example, various obstacles caused by the surface having irregularities can be greatly reduced.

Embodiments of an organic EL device and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.
<Image structure>
FIG. 4A is a plan view showing one pixel formed on the surface of one substrate of the organic EL display device and a portion in the vicinity thereof. Each pixel of the organic EL display device is formed in a matrix on the surface of the substrate, for example, one of which is shown in FIG. Each of these pixels incorporates a fine circuit by laminating conductive layers, semiconductor layers, insulating layers and the like (various layers having different conductivities) formed in a predetermined pattern.

  That is, the one pixel is defined by a gate signal line GL that selectively drives the pixel on the upper side in the drawing, is defined by a drain signal line DL that supplies a video signal to the pixel on the left side, and a current is supplied to the pixel on the right side. Is defined by a current supply line PL that supplies the pixel, and is defined by a gate signal line GL that selectively drives other pixels adjacent to the pixel on the lower side.

  This one pixel region is divided into an upper side and a lower side in the figure, a light emitting layer composed of an organic EL layer is formed in the lower region, and a current corresponding to the video signal is formed in the upper region. A circuit is formed.

  In the region where the light emitting layer is formed, one electrode (indicated by ITO in the figure) made of a light-transmitting conductive layer, the light emitting layer, and the other electrode are sequentially laminated from the substrate side. The light emitting layer is formed by being embedded in an opening (BMP, OPN in the figure) of the bank layer formed on the upper layer of the one electrode, and this portion is substantially configured as a light emitting portion. The other electrode is also formed in common for each pixel covering the upper surface of the bank layer.

  With the one electrode serving as an anode and the other electrode serving as a cathode, a current flows through the light emitting layer therebetween, whereby the light emitting layer emits light with an intensity corresponding to the current. The bank layer is for avoiding that light emitted from the pixel is transmitted to adjacent pixels, or for forming a light-emitting layer having initial fluidity in a manufacturing process so as to have a predetermined contour. Is provided.

  The region formed in the circuit includes switching elements SW1, SW2, SW3, a control signal line CL1 for turning on / off the switching element SW2, a control signal line CL2 for turning on / off the switching element SW3, a drive transistor DT, Capacitance elements C1-CSi and CSi-C2 are formed. The switching elements SW1, SW2, SW3 and the drive transistor DT are called thin film transistors and have a so-called MIS (Metal Insulator Semiconductor) structure.

  This circuit captures a video signal from the drain signal line DL by a scanning signal from the gate signal line GL, and the light emitting layer forms the current from the current supply line PL according to the strength (voltage) of this video signal. This is supplied to one electrode in the region.

  Here, the switching elements SW2 and SW3 and the capacitive element Csi-C2 are provided to correct the variation when the threshold voltage of the drive transistor DT varies for each pixel.

<< Equivalent circuit >>
FIG. 4B shows an equivalent circuit in the one pixel, which is drawn so as to substantially correspond to the geometrical arrangement in FIG.

  The switching element SW1 is turned on by the scanning signal from the gate signal line GL, and the video signal from the drain signal line DL is supplied to one electrode C1 of the capacitive element C1-CSi via the switching element SW1. At this time, the other electrode of the capacitive element C1-CSi is in a floating state.

  The capacitive element C1-CSi has a function of maintaining the gate potential of the drive transistor DT having the other electrode and a gate electrode having a conductive potential at a desired value over a predetermined period.

  In such a state, first, the control signal transmitted through the control signal line CL1 turns on the switching element SW2. At this time, although the drive transistor DT is not turned on, the node CH2 side is connected from the floating state to the reference potential through the organic EL element LED, and the potential rises to a predetermined value.

  Next, the control signal transmitted through the control signal line CL2 turns on the corresponding switching element SW3. Thereby, one electrode CSi of the capacitive element CSi-C2 in the floating state is connected to the node CH2 side of the drive transistor DT through the switching element SW3, and the potential thereof rises to the predetermined value. At this time, since the gate potential of the drive transistor DT (potential of the node CH1) is the same as the output side (node CH2), the channel layer of the drive transistor DT blocks the flow of charge.

  Since a predetermined current flows through the current supply line PL regardless of the video signal transmitted through the drain signal line DL, the potential thereof is substantially constant. Accordingly, when the two switching elements SW2 and SW3 are sequentially turned on (the respective channel layers are sequentially turned on), substantially the same amount of electric charge is stored in the capacitive element CSi-C2 of any pixel.

  In this state, when the channel layer of the switching element SW3 is closed and then the switching element SW1 is turned on, the capacitance is changed according to the voltage (video signal) applied to one electrode C1 of the capacitive element C1-CSi. The capacitance of the element C1-CSi also changes, and accordingly, a difference occurs between the potential of the node CH1 (gate potential of the drive transistor DT) and the output side (node CH2 side).

  Due to this potential difference, the drive transistor DT is turned on, and the amount of electric charge flowing through the turned-on channel is controlled to cause the organic EL element LED to emit light with a desired luminance.

  In this embodiment, the pixel configuration includes the correction circuit as described above. However, the pixel configuration may not include such a correction circuit. Basically, a switching element SW1 that is turned on by a scanning signal from the gate signal line GL, and a configuration in which a current corresponding to a video signal from the drain signal line DL flows to the organic EL element LED via the switching element SW1. If it is.

<< Production Method 1 >>
FIG. 1 is a process chart showing an embodiment of a method for manufacturing an organic EL display device according to the present invention. This will be described in the order of steps.
Step 1. (Fig. 1 (a))
First, the porous alumina substrate 1 is prepared. The porous alumina substrate 1 is a substrate formed with holes penetrating through its surface, and the size thereof is substantially equal to that of an organic EL display device to be manufactured.

  A release layer 2 is formed by applying a release agent over the entire surface of the porous alumina substrate 1. The release layer 2 is formed so that the release agent is formed on the surface opposite to the coating surface through the holes.

  Then, it is pressed against a flat substrate 3 coated with Teflon on one surface of the porous alumina substrate 1 on which the release layer 2 is formed, and the release layer 3 is heated at about 500 ° C. to be hardened.

  Here, as the release agent, for example, an aqueous solution of silicon hydroxide mixed with a fine powder of 100 nm or less made of alumina and a silica powder of about 1 μm in a volume ratio of about 3: 5 and kneaded. use.

Step 2. (Fig. 1 (b))
By removing the flat substrate 3, the surface of the release layer 2 on which the flat substrate 3 is pressed is formed flat and smooth. The porous alumina substrate 1 shown in FIG. 1 (b) is shown by turning it over in FIG. 1 (a), and the smooth surface of the release layer 2 is the upper side in the drawing.

  Then, for example, tantalum oxide is sputtered over the entire smooth surface of the release layer 2 to form a tantalum oxide layer. This tantalum oxide layer functions as an etch stopper layer 4 in a later step.

Step 3. (Fig. 1 (c))
For example, a silicon nitride film and a silicon oxide film are sequentially formed as a base layer over the entire upper surface of the etch stopper layer 4 by a CVD method, and a conductor layer, a semiconductor layer, and an insulator layer having a predetermined pattern (various layers having different conductivities). ) To form the stacked body 5 in which these are stacked in a predetermined order, so that each pixel arranged in a matrix is formed halfway.

  That is, in this step, various thin film transistors such as the gate signal line GL, the drain signal line DL, other signal lines, the switching element SW1 and the drive transistor DT shown in FIG. The layers up to the bump layer BP are formed so as to define the pixel. The bump layer BP is used to form an organic EL made of a fluid at a fixed position in an opening formed in the bump layer BP, and to prevent the light from the organic EL from being transmitted to other adjacent pixels. Is provided.

  Thereby, the formation of the light emitting layer made of organic EL and the formation of the cathode formed on the upper surface of the light emitting layer remain until the pixel is completely formed.

  In the previous step of forming the bump layer BP, an anode exposed from the opening of the bump layer BP is formed on the uppermost layer of the laminate 5 using the conductor layer, the semiconductor layer, and the insulator layer. Yes. This anode is one electrode for flowing a current to the light emitting layer. In this embodiment, the anode is formed of a transparent conductive film made of, for example, an ITO (Indium Tin Oxide) film. It is because it is set as the structure which radiate | emits the light of the said light emitting layer to the said laminated body 5 side. In this case, a part of a signal line for supplying a signal from the outside is drawn out to the uppermost layer of the stacked body 5, and its terminal portion is formed in a part of the periphery of the stacked body 5. By using the ITO film as the material of the terminal portion, for example, it is possible to avoid the electrolytic corrosion of the terminal portion.

Step 4. (Fig. 1 (d))
A polyethylene film is attached to the upper surface of the laminate 5. This polyethylene film functions as a transfer body 6 to be removed in a later step.

Step 5. (Fig. 1 (e))
The porous alumina substrate 1 is removed. The removal in this case is performed by, for example, dissolving the silica gel and silica that are components of the release layer 2 using hydrofluoric acid. In this case, the hydrofluoric acid is prevented from eroding each member formed in the laminate 5 by the etch stopper layer 4 formed in step 2.

Step 6. (Fig. 1 (f))
The etch stopper layer 4 is formed on the surface of the laminate from which the porous alumina substrate 1 has been removed, and a film is attached to the surface of the etch stopper layer 4. This film becomes the substrate 7 on one side of the organic EL display device. For this reason, it is preferable to select engineering plastics such as polyethylene terephthalate and polycarbonate as the material of the substrate 7. This is because it is excellent in terms of strength, tensile strength and dimensional stability.

  Then, the transfer body 6 bonded to the other surface of the laminate 5 is removed. By removing the transfer body 6, a processed surface up to the bump layer BP formed in the step 3 appears on the surface of the multilayer body 5.

Step 7. (Fig. 1 (g))
A light emitting layer 9 made of organic EL is formed in the opening of the bump layer BP, and a common cathode 8 connected to the light emitting layer of the adjacent pixel is formed on the upper surface of the light emitting layer 9. A part of the cathode 8 is drawn out as one of the terminal portions formed in the step 3.

  As described above, the step (FIG. 1C) for forming the thin film transistor and the like is separated from the present step for forming the light emitting layer 9 and the like. The step with moisture after the formation of the light emitting layer 9 is performed. This is because of avoidance.

Step 8 (FIG. 1 (h))
A film is attached to the surface on which the cathode 8 is formed. This film serves as the other substrate 11 of the organic EL display device, and shields the light emitting layer 9 from the outside air by oxidizing or avoiding moisture.
For this reason, it is preferable to use the substrate 11 having a desiccant interposed in the film direction.

  The substrate 11 is formed so as to expose a terminal portion formed on the surface of the laminate 5, and an organic EL display device is completed by connecting the flexible wiring substrate 13 to the terminal portion.

  The flexible wiring board 13 supplies various signals to the signal lines formed in the laminated body through the flexible wiring board 13. Further, the connection between the terminal portion and the flexible wiring board 13 is made, for example, via an anisotropic conductive film 12.

<< Production Method 2 >>
FIG. 2 is a process diagram showing another embodiment of the organic EL display device according to the present invention. Hereinafter, it demonstrates in order of a process.
Step 1. (Fig. 2 (a))
First, the porous alumina substrate 21 is prepared. The porous alumina substrate 21 is a substrate formed with holes penetrating through its surface, and the size thereof is substantially the same as that of an organic EL display device to be manufactured.

  A release layer 22 is formed by applying a release agent to the entire surface of the porous alumina substrate 21. The release layer 22 is formed so that the release agent is formed on the surface opposite to the coating surface through the holes.

  Then, it is pressed against a flat substrate 23 coated with Teflon on one surface of the porous alumina substrate 21 on which the release layer 22 is formed, and the release layer 22 is heated at about 500 ° C. to be hardened.

  Here, as the release agent, for example, an aqueous solution of silicon hydroxide mixed with a fine powder of 100 nm or less made of alumina and a silica powder of about 1 μm in a volume ratio of about 3: 5 and kneaded. use.

Step 2. (Fig. 2 (b))
By removing the flat substrate 23, the surface of the release layer 22 on which the flat substrate 23 has been pressed is formed flat and smooth. The porous alumina substrate 21 shown in FIG. 2 (b) is shown upside down as shown in FIG. 2 (a), and the smooth surface of the release layer 22 is the upper side in the drawing.

  Then, for example, an ITO film 40 is formed over the entire smooth surface of the release layer 22, and this ITO film 40 is selectively etched into a predetermined pattern. This ITO film functions as the anode and terminal of the organic EL display device, and is therefore etched according to the pattern.

  Next, the surface on which the ITO film 40 is formed is covered with the ITO film 40, and an oxide of tantalum is sputtered, thereby forming a tantalum oxide layer. This tantalum oxide layer functions as an etch stopper layer 24 in a later step.

Step 3. (Fig. 2 (c))
A silicon nitride film and a silicon oxide film are sequentially formed on the upper surface of the etch stopper layer 24 by CVD as a base layer, and a polysilicon layer which is a semiconductor layer of a thin film transistor, a gate insulating film, a gate electrode, implantation, annealing, an interlayer insulating film Then, electrodes and wiring layers respectively connected to the source and drain regions of the thin film transistor are sequentially formed.

  In other words, an electronic circuit is formed by a laminate 25 in which a conductor layer, a semiconductor layer, and an insulator layer formed in a predetermined pattern are stacked in a predetermined order.

  In this case, a contact hole is formed in the interlayer insulating film as a step before forming electrodes connected to the source and drain regions of the thin film transistor. Further, when the wiring layer 41 connected to the anode (ITO film 40) is formed on the upper surface of the interlayer insulating film, contact holes are also formed in the interlayer insulating film and further in the tantalum oxide film as the etch stopper layer 24. However, it is necessary to form a contact hole in the tantalum oxide film by performing the dry etching.

Step 4. (Fig. 2 (d))
A substrate 26 made of plastic, for example, is attached to the surface of the laminate 25 formed in the above process, and this substrate 26 is used as one substrate of the organic EL display device.

Step 5. (Fig. 2 (e))
The release layer 22 to which the porous alumina substrate 21 is attached is dissolved, and the porous alumina substrate 21 is removed.

  The laminated body 25 formed in the step 3 is transferred to the substrate 26 side, and the exposed surface of the laminated body 25 is formed in the step 2 and includes an anode and a terminal of the organic EL display device. The ITO film 40 formed as shown above appears. The ITO film 40 is embedded in an etch stopper layer 24 made of a tantalum oxide layer. In other words, the ITO film 40 is embedded in the region where the etch stopper layer 24 is formed so that the surface thereof is flush with the surface of the etch stopper layer 24. Is formed.

Step 6. (Fig. 2 (f))
On the exposed flat surface of the laminate 25, an organic material layer group 42 including an electron injection layer, an electron transport layer, a light emitting layer, and a hole transport layer is formed by vapor deposition. The organic layer group 42 constitutes a light emitting portion in each pixel, and is formed so as to be superimposed on the anode of each pixel. Further, the light emitting layer of the organic layer group 42 has one of the three primary colors, and can be formed in a state of being connected to each other when the same color is assigned to other adjacent pixels.

  In addition, the hole transport layer, the electron transport layer, or the electron injection layer is formed as necessary, and one or two of them may not be formed depending on circumstances.

  Thereafter, the cathode 43 is formed so as to overlap the organic layer group 42 by, for example, vapor deposition. Since the cathode 43 is connected to each other and the same signal is applied to each pixel, the cathode 43 is formed in common across the pixels.

Step 7. (Fig. 2 (g))
A film is attached so as to sufficiently cover at least a portion where the cathode 43 is formed on the surface of the laminate, and this film is configured as the other substrate 27 of the organic EL display device.

  The substrate 27 has a function of shielding the outside air because the characteristics of the light emitting layer are deteriorated due to oxidation, moisture, etc., and is configured by interposing a desiccant, for example.

Step 8. (Fig. 2 (h))
A flexible wiring board 29 is connected to the surface of the laminate 25 and the terminal exposed from the board 27. The flexible wiring board 29 and the terminals are connected via the anisotropic conductive film 28.

  The manufacturing method shown in the second embodiment can reduce the number of steps because the number of times of transfer used in the manufacturing method is one, and therefore, it is possible to reduce the damage caused by an external failure such as a wiring layer connected to the thin film transistor. Play. Further, the anode and the terminal of the light emitting layer have a flat surface continuous with the tantalum oxide film, and there are no steps on the surface. For this reason, there exists an effect which can avoid the mutual short circuit of the anode and cathode formed with a thin light emitting layer in between.

<< Production Method 3 >>
In the organic EL display device shown in Example 2, a light-transmitting material is used for the anode of the light emitting layer, and a non-light-transmitting material is used for the cathode. However, these may be reversed to use a non-translucent material for the anode and a translucent material for the cathode.

  In this case, the thin film transistor and the wiring layer connected to the thin film transistor can be formed under the cathode, and the light emitting area of the light emitting layer can be increased without reducing the area. Hereinafter, an embodiment of the manufacturing method will be described with reference to FIG. The manufacturing process shown in FIG. 3 is almost the same as the manufacturing process shown in FIG.

Step 1. (Fig. 3 (a))
First, the porous alumina substrate 21 is prepared. The porous alumina substrate 21 is a substrate formed with holes penetrating through its surface, and the size thereof is substantially the same as that of an organic EL display device to be manufactured.

  A release layer 22 is formed by applying a release agent to the entire surface of the porous alumina substrate 21. The release layer 22 is formed so that the release agent is formed on the surface opposite to the coating surface through the holes.

  Then, it is pressed against a flat substrate 23 coated with Teflon on one surface of the porous alumina substrate 21 on which the release layer 22 is formed, and the release layer 3 is heated at about 500 ° C. to be hardened.

  Here, as the release agent, for example, an aqueous solution of silicon hydroxide mixed with a fine powder of 100 nm or less made of alumina and a silica powder of about 1 μm in a volume ratio of about 3: 5 and kneaded. use.

Step 2. (Fig. 3 (b))
By removing the flat substrate 23, the surface of the release layer 22 on which the flat substrate 23 has been pressed is formed flat and smooth. The porous alumina substrate 21 shown in FIG. 2 (b) is shown upside down as shown in FIG. 1 (a), and the smooth surface of the release layer 22 is the upper side in the drawing.

  Then, for example, a Mo / Al laminated film 40 ′ is formed over the entire smooth surface of the release layer 22, and this Mo / Al laminated film 40 ′ is selectively etched into a predetermined pattern. The Mo / Al laminated film 40 'functions as an anode and a terminal of the organic EL display device, and is therefore etched according to the pattern.

  Next, the surface on which the Mo / Al laminated film 40 'is formed is covered with the Mo / Al laminated film 40', and tantalum oxide is sputtered to form a tantalum oxide layer. This tantalum oxide layer functions as an etch stopper layer 24 in a later step.

Step 3. (Fig. 3 (c))
A silicon nitride film and a silicon oxide film are sequentially formed on the upper surface of the etch stopper layer 24 by CVD as a base layer, and a polysilicon layer which is a semiconductor layer of a thin film transistor, a gate insulating film, a gate electrode, implantation, annealing, an interlayer insulating film Then, electrodes and wiring layers respectively connected to the source and drain regions of the thin film transistor are sequentially formed.

  In other words, an electronic circuit is formed by a laminate 25 in which a conductor layer, a semiconductor layer, and an insulator layer formed in a predetermined pattern are stacked in a predetermined order.

  In this case, a contact hole is formed in the interlayer insulating film as a step before forming electrodes connected to the source and drain regions of the thin film transistor. Further, when the wiring layer 41 connected to the anode (Mo / Al laminated film 40 ′) is formed on the upper surface of the interlayer insulating film, the interlayer insulating film and also the tantalum oxide film as the etch stopper layer 24 are used. Although it is necessary to form a contact hole, the contact hole can be formed also in the tantalum oxide film by forming the contact hole by dry etching.

Step 4. (Fig. 3 (d))
A substrate 26 made of plastic, for example, is attached to the surface of the laminate formed in the above process, and this substrate 26 is used as one substrate of the organic EL display device.

Step 5. (Fig. 3 (e))
The release layer 22 to which the porous alumina substrate 21 is attached is dissolved, and the porous alumina substrate 21 is removed.

  The laminated body 25 formed in the step 3 is transferred to the substrate 26 side, and the exposed surface of the laminated body 25 is formed in the step 2 and includes an anode and a terminal of the organic EL display device. As a result, a Mo / Al laminated film 40 ′ formed as shown in FIG. The Mo / Al laminated film 40 ′ is in a state of being embedded in the etch stopper layer 24 made of a tantalum oxide layer. That is, in the region where the etch stopper layer 24 is formed, the Mo / Al laminated film 40 ′ is embedded in a state where the surface thereof is flush with the surface of the etch stopper layer 24. A smooth flat surface is formed.

Step 6. (Fig. 3 (f))
This surface is subjected to dry etching using a fluorine-based gas to remove Mo from the Mo / Al laminated film 40 ′ to expose Al.

  Next, an organic layer group 42 including an electron injection layer, an electron transport layer, a light emitting layer, and a hole transport layer is formed on the exposed flat surface of the laminate 25 by a vapor deposition method. The organic layer group 42 constitutes a light emitting portion in each pixel, and is formed so as to be superimposed on the anode of each pixel. Further, the light emitting layer of the organic layer group 42 has one of the three primary colors, and can be formed in a state of being connected to each other when the same color is assigned to other adjacent pixels.

  In addition, the hole transport layer, the electron transport layer, or the electron injection layer is formed as necessary, and one or two of them may not be formed depending on circumstances.

  Thereafter, a cathode 43 ′ is formed by, for example, vapor deposition so as to overlap with the organic layer group 42. The cathode 43 ′ is made of, for example, an ITO (Indium Tin Oxide) film, and is connected to each other and the same signal is applied to each pixel. The light of the light emitting layer emitted by energizing the anode and cathode 43 'is emitted to the outside of the organic EL display device through the cathode 43'. The light directed to the anode side is efficiently reflected and passes through the cathode 43 'because the anode is made of Al.

Step 7. (Fig. 3 (g))
A film is attached so as to sufficiently cover at least a portion where the cathode 43 ′ is formed on the surface of the laminate, and this film is configured as the other substrate 27 of the organic EL display device.

  The substrate 27 has a function of shielding the outside air because the characteristics of the light emitting layer are deteriorated due to oxidation, moisture, etc., and is configured by interposing a desiccant, for example.

Step 8. (Fig. 3 (h))
A flexible wiring board 29 is connected to the surface of the laminate 25 and the terminal exposed from the board 27. The flexible wiring board 29 and the terminals are connected via the anisotropic conductive film 28.

It is process drawing which shows one Example of the manufacturing method of the organic electroluminescent display apparatus by this invention. It is process drawing which shows the other Example of the manufacturing method of the organic electroluminescent display apparatus by this invention. It is process drawing which shows the other Example of the manufacturing method of the organic electroluminescent display apparatus by this invention. It is a top view which shows one Example of a structure of one pixel formed in the surface of one board | substrate of the organic electroluminescent display apparatus by this invention, and its vicinity.

Explanation of symbols

GL: Gate signal line, DL: Drain signal line, 1, 21 ... Porous alumina substrate, 2, 22 ... Release layer, 3, 23 ... Flat substrate, 4, 24 ... Etch stopper layer, 5, 25 …… Laminate, 7, 11, 26, 27 …… Substrate, 8, 43, 43 ′ …… Cathode, 9 …… Light emitting layer, 13, 29 …… Flexible wiring substrate, 12, 28 …… Anisotropy Conductive film, 40 ... ITO film, 41 ... wiring layer, 42 ... organic matter group, BP ... bump layer.

Claims (20)

Forming a conductive film on the surface of the first temporary substrate;
After patterning the conductive film as an anode of a light emitting element, another conductive film having a different conductivity from the conductive film is sequentially formed on the surface of the first temporary substrate, and the patterned conductive film Forming an electronic circuit composed of a laminate including the other conductive film;
Attaching a second temporary substrate to the first surface of the laminate opposite to the first temporary substrate;
Removing the first temporary substrate from the laminate;
Attaching the first flexible substrate to the second surface exposed by removing the first temporary substrate of the laminate;
A step of attaching a second flexible substrate to the first surface after removing the second temporary substrate from the first surface of the laminate,
The method of manufacturing an organic EL display device, wherein the first temporary substrate has a plurality of holes formed on a surface thereof, and at least a surface on which the conductive film is formed is covered with a release agent including the plurality of holes.   The method of manufacturing an organic EL display device according to claim 1, wherein a surface of the release agent covering a surface on which the conductive film of the first temporary substrate is formed is processed flat.   After attaching the first flexible substrate to the second surface of the laminate and removing the second temporary substrate from the first surface of the laminate, at least on the first surface of the laminate An organic material film including a light-emitting layer and a cathode of the light-emitting element overlapping the organic material film are formed, and after the formation of the cathode, the second flexible substrate covers at least the organic material film and the stacked layer The method for manufacturing an organic EL display device according to claim 1, wherein the organic EL display device is attached to the first surface side of a body.   The organic EL film according to claim 3, wherein the organic material film is formed by laminating at least one of a hole transport layer, an electron transport layer, and an electron injection layer on the light emitting layer on the cathode of the light emitting element. Manufacturing method of display device.   2. The method of manufacturing an organic EL display device according to claim 1, wherein the plurality of holes are uniformly distributed on the surface of the first temporary substrate. 3. Forming a transparent conductive film on the flat surface of the temporary substrate;
After patterning the transparent conductive film as an anode of a light emitting element, a laminate including the patterned transparent conductive film and another conductive film having different conductivity on the flat surface of the temporary substrate Forming an electronic circuit by:
A step of attaching a first flexible substrate to a surface of the laminate opposite to the temporary substrate;
Removing the temporary substrate from the surface on which the transparent conductive film of the laminate is formed;
A step of affixing a second flexible substrate to the surface on which the transparent conductive film of the laminate is formed,
The temporary substrate has a plurality of holes formed on a surface thereof, and at least a surface in contact with the stacked body is covered with a release agent including the plurality of holes. Preparing a temporary substrate in which a plurality of holes are formed and covered with a release agent including the plurality of holes;
Forming a transparent conductive film pattern on the surface of the release agent covering the temporary substrate;
A step of covering the transparent conductive film with an insulating material film that is less soluble in a liquid for removing the release agent than the release agent;
A step of disposing another conductive film having a conductivity different from that of the transparent conductive film on the insulating material film to form a laminate of an electronic circuit using the transparent conductive film as an anode of a light emitting element;
A step of attaching a first flexible substrate to a surface of the laminate on which the other conductive film is disposed;
Removing the release agent from the liquid and removing the temporary substrate from the surface of the laminate on which the transparent conductive film is formed;
A method of manufacturing an organic EL display device, comprising: attaching a second flexible substrate to a surface of the laminate on which the transparent electrode film is formed.   The method of manufacturing an organic EL display device according to claim 6, wherein a surface of the release agent that covers the temporary substrate and on which the pattern of the transparent conductive film is formed is processed flat.   At least a light emitting layer is included on the transparent conductive film of the laminate between the step of attaching the first flexible substrate to the laminate and the step of attaching the second flexible substrate to the laminate. The method for manufacturing an organic EL display device according to claim 6, further comprising a step of forming an organic material film and a cathode of the light emitting element superimposed on the organic material film.   The organic EL film according to claim 9, wherein the organic material film is formed by laminating at least one of a hole transport layer, an electron transport layer, and an electron injection layer on the light emitting layer on the cathode of the light emitting element. Manufacturing method of display device.   The method for manufacturing an organic EL display device according to claim 6, wherein the plurality of holes are uniformly distributed on the surface of the temporary substrate. An insulating layer having a first main surface and a second main surface opposite thereto; a plurality of first conductive films formed on the first main surface of the insulating layer; and at least one of the plurality of first conductive films A light emitting element formed by sequentially laminating an organic material layer including a light emitting layer and an electrode layer, and a plurality of first conductive films formed on the second main surface of the insulating layer and through the insulating layer. A laminated structure including a plurality of second conductive films electrically connected to each other;
A first flexible substrate in contact with the first main surface side of the insulating layer of the laminated structure; and
A second flexible substrate in contact with the second main surface side of the insulating layer of the laminated structure;
Each of the plurality of first conductive films is an organic EL display device in which a part thereof is exposed from the first main surface of the insulating layer and a part other than the part is embedded in the insulating layer.   The organic EL display device according to claim 12, wherein the first flexible substrate covers the light emitting element formed by stacking the organic material layer and the electrode layer on the at least one of the plurality of first conductive films. .   The organic EL display device according to claim 12, wherein at least one of the plurality of first conductive films different from the at least one is exposed from the first flexible substrate.   The surface of the plurality of first conductive films exposed from the at least one other first flexible substrate is flush with the first main surface of the insulating layer exposed from the first flexible substrate adjacent thereto. The organic EL display device according to claim 14.   An electronic circuit including at least one of the plurality of second conductive films connected to the at least one of the plurality of first conductive films through the insulating layer is formed on the second main surface of the insulating layer, The organic EL display device according to claim 12, wherein the electronic circuit is covered with the second flexible substrate. A group including the at least one of the plurality of first conductive films is two-dimensionally arranged on the first main surface of the insulating layer, and the light emitting layer is disposed on each of the group of the plurality of first conductive films. A display screen comprising a plurality of the light emitting elements is formed by sequentially laminating the organic material layer and the electrode layer,
The organic EL display device according to claim 12, wherein surfaces of the group of first conductive films exposed from the first main surface of the insulating layer are flush with the first main surface. A light emitting device including at least one first electrode layer, an organic material layer and a second electrode layer sequentially stacked on the first electrode layer and the first surface; and the first electrode layer and the first surface. A laminated body having an electronic circuit including a conductive layer laminated on the opposing second surface side, and a pair of flexible substrates sandwiching the laminated body from the light emitting element side and the electronic circuit side,
The organic material layer includes a light emitting layer,
The boundary surface including the first surface of the at least one first electrode layer of the laminate includes the surface on the light emitting element side of the insulating layer in contact with the second surface of the at least one first electrode layer. Display device. A third electrode layer formed on the light emitting element side of the insulating layer and electrically connected to at least one of the conductive layers constituting the electronic circuit through the insulating layer;
19. The organic EL according to claim 18, wherein a surface of the third electrode layer on the light emitting element side is included in the boundary surface of the multilayer body and exposed from one of the pair of flexible substrates covering the light emitting element. Display device. A plurality of the first electrode layers are two-dimensionally arranged apart from each other by the insulating layer, and the organic material layer and the second electrode layer are stacked in this order on the first surface of each of the first electrode layers. A display screen having a plurality of the light emitting elements is formed,
Each of the plurality of first electrode layers is electrically connected to a corresponding one of the conductive films included in the electronic circuit through the insulating layer,
The organic EL display device according to claim 18, wherein the first surface of each of the first electrode layers is included in the boundary surface of the multilayer body.

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