JP2003017249A - Display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in display quality due to occurrence of emission irregularity in the picture element when the luminous layer of the OLED display panel is formed using an ink jet method. SOLUTION: A luminous layer-formed film, on which a luminous layer is formed beforehand on a base film, is pasted on a substrate and laser irradiation is applied selectively, and a luminous layer having a desired pattern is formed, and then the base film is peeled off, thereby forming the luminous layer by a laser thermal transfer method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a display device and an OL.
The present invention relates to a method for manufacturing an ED display device.

[0002]

2. Description of the Related Art A conventional OLED display device (OLED is
FIG. 9 shows a cross-sectional structure of an abbreviation for Organic Lighting Emission Diode).

The OLED display panel 31c of this OLED display device includes a switching active element 2 (hereinafter referred to as "TFT") in which both a signal line and a scanning line are formed on a glass substrate 1.
") And a flattening film 3 thereon. The TFT 2 and the pixel electrode 4 are electrically connected to the flattening film 3.

In the pixel, the hole injection layer 5 and the light emitting layers 7R, 7G, and 7B are formed on the pixel electrode 4, and the respective colors are separated by the element separation film 6. Further, a counter electrode 10 is formed on the light emitting layer 7.

Further, the glass substrate 1 and the counter glass substrate 1
An encapsulant is formed around the panel No. 0, and a purge gas 9 is filled between both glass substrates to form an OLED display panel.

[0006] Such a conventional OLED display panel 31
An inkjet method is generally used to form the light emitting layer 7 in the pixel portion c. That is, first, an element isolation film 5 that separates each pixel is formed in a gap between the pixels, and a droplet containing a luminescent agent is ejected to a desired pixel portion in a pixel portion partitioned by the element isolation film 6. Light emitting layer 7 for each color
R, 7G, and 7B are laminated on the hole injection layer 6.

Originally, a photolithography method is used as a pattern forming method for semiconductors and liquid crystal panels.
Since the material of the light emitting layer 7 used for the display panel is generally deteriorated by water contained in the developer used for the photolithography method, the same method cannot be used. Therefore, OL
In order to form the light emitting layer 7 of the ED display panel, as described above,
Generally, an inkjet method that does not require a developing step is used.

[0008]

However, when such an ink jet method is used, the droplets of the luminescent agent ejected into the pixels on the substrate do not spread evenly in the entire pixels, especially in the peripheral area of the pixels. Since the thin portion of the film is formed, unevenness of the light emitting layer 7 may occur in the pixel.

That is, since the light emitting layer 7 in the pixel has unevenness, when a voltage is applied after the panel is formed, uneven light emission occurs in the pixel and the display quality is degraded.

Further, when an ink droplet is dropped on a pixel, the ink droplet crosses over the adjacent pixel, so that it is essential to form an element isolation film between the pixels in advance. Therefore, the number of steps for forming the element isolation film is increased and the material cost of the element isolation film is added, which leads to an increase in cost.

Further, by forming an element isolation film,
The aperture ratio decreases, resulting in a panel with low brightness.

[0012]

In order to solve such a problem, the present invention provides a method for forming a light emitting layer, in which a light emitting layer forming film in which a light emitting layer is previously formed on a base film is attached on a substrate. The laser is characterized by selectively irradiating a laser from the base film side of the film to form a light emitting layer having a desired pattern, and then peeling the base film. That is, the light emitting layer is formed by a thermal transfer method.

With this method, the unevenness of the formation of the light emitting layer, which has been a problem in the ink jet method, is almost eliminated in the same method. That is, the light emitting layer forming film used in the same system,
Since the light emitting layer is formed on the base film with a gravure coater, a die coater, etc., the light emitting layer can be formed with a uniform film thickness.
By the laser irradiation, the light emitting layer is wholly transferred without remaining on the base film, so that the formed light emitting layer can have a uniform film thickness.

Further, when the same method is used, since the light emitting layer can be selectively formed by laser irradiation, the element isolation film, which is indispensable in the ink jet system, can be removed, which leads to cost reduction. In addition, a panel with a high aperture and high brightness can be realized.

On the other hand, in some cases, a high-quality OLED display panel can be realized by forming an element isolation film having a light shielding property between pixels after forming the light emitting layer.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 is a method of manufacturing a display device, which comprises a pixel electrode and a switching active element for driving the pixel electrode, and a light emitting layer is formed in a gap between the pixel electrode and a counter electrode thereof. Then, as the process, (1) a step of pasting the light emitting layer forming film in which the light emitting layer is formed on the base film in advance from the light emitting layer side on the substrate on which the pixel electrode is formed, and (2) the light emitting layer The step of irradiating a laser from the base film side of the formed film to selectively bring the light emitting layer into close contact with the pixel electrode, (3) the step of peeling the base film from the substrate, and (4) the counter electrode are formed. It is a method of manufacturing a display device, which is characterized by being formed by going through a film forming step.

By this manufacturing method, a light emitting layer having a uniform film thickness can be formed in the pixel and over the entire panel, and a panel with good display quality without unevenness can be realized.

According to a second aspect of the present invention, there is provided a method of manufacturing a display device according to the first aspect, that is, a pixel electrode and a switching active element for driving the pixel electrode are provided, and light is emitted in a gap between the pixel electrode and a counter electrode thereof. A method of manufacturing a display device in which a layer is formed, wherein the element isolation film is not formed.

By this manufacturing method, the process of forming the element isolation film can be eliminated and the cost can be reduced.

That is, when the same method is used, since the light emitting layer can be selectively formed by laser irradiation,
The element isolation film, which is indispensable when the inkjet method is used, can be removed.

Further, since there is no element isolation film, it is possible to realize an OLED display panel with high aperture and high brightness.

According to a third aspect of the present invention, there is provided a method for manufacturing a display device according to the first aspect, that is, a pixel electrode and a switching active element for driving the pixel electrode are provided, and light is emitted in a gap between the pixel electrode and a counter electrode thereof. A method of manufacturing a display device in which a layer is formed, and after forming a light emitting layer, an element isolation film having a desired pattern shape is formed.

According to this manufacturing method, the light emitting layer can be divided by the element isolation film, the contour of each light emitting layer can be made clear, and the display characteristics can be improved.

By forming the element isolation film, it is possible to realize an OLED display panel having improved display characteristics, although the cost is increased and the aperture ratio is reduced.

The present invention according to claim 4 is a display device formed by the method for manufacturing a display device according to claim 1.

When the light emitting layer is formed by the conventional ink jet method, unevenness of the light emitting layer in the pixel poses a problem, but according to the present invention, the film thickness distribution of the light emitting layer in the pixel is small, and there is no uneven light emission. Therefore, a display device with improved panel display quality can be formed.

The present invention according to claim 5 is a display device formed by the method for manufacturing a display device according to claim 2.

By using this method instead of the ink jet method which is generally used for forming the light emitting layer or the hole injecting layer, it is possible to eliminate the process for forming the element isolation film and reduce the cost. You can

The present invention according to claim 6 is a display device formed by the method for manufacturing a display device according to claim 3.

With this structure, the light emitting layer can be divided by the element isolation film, the contour of each light emitting layer can be made clear, and the display characteristics can be improved.

By forming the element isolation film, the display characteristics can be improved although the cost is increased.

(Embodiment 1) Hereinafter, a method of manufacturing an OLED display panel and a sectional structure of the panel according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

When forming an OLED display panel, first, as shown in FIG. 1A, a switching active element 2 is formed on a glass substrate 1 by general semiconductor thin film formation, insulation film formation, and photolithography. It is formed by repeating the etching by the method. Further, as shown in FIG. 3B, the flattening film 3 is formed on the glass substrate 1 forming the active element 2.
Is applied and exposed and developed to pattern a flattening film forming a contact hole having a desired shape. As the flattening film 3, an acrylic photosensitive resin is suitable.

Next, as shown in FIG. 3C, an electrode is formed on the entire surface in a vacuum, and the pixel electrode 4 is patterned to electrically connect with the active element 2 via the contact hole. The formed pixel electrode 4 can be formed.

Next, as shown in FIG. 3D, depending on the case, the element isolation film 5 is coated with a resin film, exposed, and developed in order to separate the pixels from each other. The element isolation film 5 is patterned. This element isolation film 5 is
The light emitting layer 7 formed in a later step is separated for each pixel.

Here, the laser thermal transfer method which is the method for forming the light emitting layer of the present invention will be described. FIG. 7B shows a sectional view of the structure of the light emitting layer forming film 13 used in the same system. The film 13 is formed by applying a photothermal conversion layer 13C to a desired film thickness on a polyethylene terephthalate (PET) film 13B with a gravure coater or a die coater, and then applying a light emitting layer 13D thereon. Similar to the conversion layer 13C, the above coater is used to apply a desired film thickness. At this time, the film thickness is applied as needed from the film thickness of the light emitting layer 7 when the panel is completed. Finally, the light emitting layer forming film 13 is formed by attaching the cover film 13F.

Next, a method of laminating a film on a substrate of the same system will be described with reference to FIG.

First, the roll around which the light emitting layer forming film 13 is wound is fixed to the film unwinding portion 21. Of the light emitting layer forming film 13 unwound from the same portion, only the cover film 13F is peeled off and wound up by the cover film winding portion 22. Next, this film is sandwiched between the glass substrate 11 and the elastic roll 23 to fix the light emitting layer forming film 13A on the glass substrate 11, and the film cutting portion 24 cuts the film to form the light emitting layer forming film. A glass substrate to which 13A is fixed is formed.

Next, the process of transferring the light emitting layer onto the substrate by the laser thermal transfer method will be described with reference to the sectional view of the structure of FIG.

As shown in FIG. 8A, the laser 12 is selectively irradiated from the film on the substrate 11 to which the light emitting layer forming film 13A is fixed. At this time, the laser irradiation causes the carbon layer 13C to generate heat, and this heat causes the light emitting layer 7 to peel off from the carbon layer 13C and adhere onto the substrate 11. Further, as shown in FIG. 8B, by selectively scanning the laser light 12 on the substrate 11, the light emitting layer 7 having a desired pattern can be formed over the entire substrate. The laser used is preferably a YAG laser, and the patterning width can be changed by controlling the irradiation width of the laser.

After that, the base film is peeled off to complete the substrate on which the light emitting layer 7 is formed.

Here, as shown in FIG. 1E, the hole transport layer 6 is formed on the substrate 11a on which the device isolation film 5 is formed, and the laser thermal transfer method described above is applied. The light emitting layer 7 is selectively formed by using this. By repeating this three times, the light emitting layers 7R, 7G, and 7B for each of RGB are formed as shown in FIG.

In the above description, the case where the laser thermal transfer system is used to form the light emitting layer 7 has been described, but in some cases,
The hole transport layer 6 may be formed by using the laser thermal transfer method.

Next, as shown in FIG. 1G, the ITO film 8 is formed by sputtering.

Finally, as shown in FIG. 1 (h), a purge gas 9 is sealed in the gap with the counter glass substrate 10 and the peripheral portion of the panel is fixed, so that a cross-section is shown in FIG. Such an OLED display panel 31a is formed.

(Embodiment 2) Hereinafter, based on the embodiments of the present invention, the manufacturing method of the OLED display panel and the cross-sectional structure of the panel according to the embodiments of the present invention will be described with reference to FIGS. 3 and 4. Will be explained.

When forming the OLED display panel, as shown in FIG.
Since the processes from (a) to (c) for forming the pixel electrode 4 are the same as those in the first embodiment, description thereof will be omitted.

Next, as shown in FIG. 3D, the hole transport layer 6 is formed, and then, as shown in FIG. 1E, the light emitting layer 7R is formed by using the laser thermal transfer method. Then, the light emitting layers 7R, 7G, and 7B are formed by repeating this three times.

In the above description, the case where the laser thermal transfer system is used to form the light emitting layer 7 has been described.
The hole transport layer 6 may be formed by using the laser thermal transfer method.

Next, as shown in FIG. 3G, the ITO film 8 is formed by sputtering.

Finally, as shown in FIG. 3 (h), a purge gas 9 is filled in the gap with the counter glass substrate 10 and the peripheral portion of the panel is fixed, so that the cross section of the structure is shown in FIG. OLED display panel is formed.

With this structure, since the element isolation film 5 is not formed, the material can be reduced, the man-hours can be reduced, and the production can be increased, so that the cost can be reduced. In addition, since the element isolation film is not formed, the aperture ratio can be widened and the high brightness OLE can be obtained.
The D display panel 31b can be realized.

(Embodiment 3) Hereinafter, based on the embodiment of the present invention, the manufacturing method of the OLED display panel and the cross-sectional structure of the panel will be described with reference to FIGS. Will be explained.

When forming the OLED display panel, as shown in FIG.
Since the processes from (a) to (c) for forming the pixel electrode 4 are the same as those in the first embodiment, description thereof will be omitted.

Next, as shown in FIG. 5 (d), the hole transport layer 6 is formed, and then, as shown in FIG. 5 (e), the light emitting layer 7R is formed by using the laser thermal transfer method. Then, the light emitting layers 7R, 7G, and 7B are formed by repeating this three times.

In the above, the case where the laser thermal transfer system is used for forming the light emitting layer 7 has been described, but in some cases,
The hole transport layer 6 may be formed by using the laser thermal transfer method. Thereafter, as shown in FIG. 5F, the element isolation film 5 having a light shielding property is formed in a desired pattern shape by using the laser thermal transfer method. As the element separation film 5, a light-shielding color material containing an organic pigment as a main material is suitable.

Next, as shown in FIG. 5G, the ITO film 8 is formed by sputtering.

Finally, as shown in FIG. 5 (h), a purge gas 9 is filled in the gap with the counter glass substrate 10 and the peripheral portion of the panel is fixed, so that a cross section of the structure is shown in FIG. OLED display panel is formed.

With this structure, the light emitting layer can be divided by the element isolation film, the contour of each light emitting layer can be made clear, and the display characteristics can be improved.

By forming the element isolation film, it is possible to realize the OLED display panel 31c having improved display characteristics, although the cost is increased and the aperture ratio is reduced.

The pixel array is a matrix type array or a delta type array. The pixel array is shown in the perspective view of FIG.

[0062]

As described above, according to the present invention, OLE
By using the laser thermal transfer method for forming the light emitting layer of the D display panel, the unevenness in the formation of the light emitting layer, which has been a problem in the ink jet method, is almost eliminated in the same method.

When the same method is used, since the light emitting layer can be selectively formed by laser irradiation, the element isolation film which is indispensable in the ink jet system can be removed, which not only leads to cost reduction. A panel with high aperture and high brightness can be realized.

Further, after forming the light emitting layer, an element isolation film having a light shielding property is formed between the pixels, so that a high quality OL can be obtained.
An ED display panel can be realized.

[Brief description of drawings]

1A to 1H are cross-sectional views of respective steps of a method of manufacturing an OLED display panel showing an embodiment of the present invention using a laser thermal transfer system.

FIG. 2 is a sectional view of an OLED display panel showing an embodiment of the present invention using a laser thermal transfer system.

3A to 3G are cross-sectional views of respective steps of a method of manufacturing an OLED display panel showing a second embodiment of the present invention using a laser thermal transfer system.

FIG. 4 is a sectional view of an OLED display panel showing a second embodiment of the present invention using a laser thermal transfer system.

5 (a) to 5 (h) are cross-sectional views of respective steps of a method of manufacturing an OLED display panel showing a third embodiment of the present invention using a laser thermal transfer system.

FIG. 6 is a sectional view of an OLED display panel showing a third embodiment of the present invention using a laser thermal transfer system.

7A is a view showing a film fixing method of a laser thermal transfer system, and FIG. 7B is a sectional view showing a structure of a film used in the same system.

8A is a sectional view showing a laser irradiation step of a laser thermal transfer system, and FIG. 8B is a perspective view thereof.

FIG. 9 is a sectional view of an OLED display panel showing a conventional example.

[Explanation of symbols]

1 glass substrate 2 TFT 3 Flattening film 4 pixel electrodes 5 element isolation film 6 Hole transport layer 7 Light-emitting layer 8 Counter electrode 9 page gas 10 Opposite glass substrate 11 Array substrate 12 laser light 13 Light emitting layer forming film 21 Film unwinding section 22 Cover film winding section 23 Elastic Roll 24 Film cutting section 31 OLED display panel

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 B 33/22 33/22 ZF term (reference) 3K007 AB04 AB17 AB18 BA06 BB01 BB04 CB01 DA01 DB03 EB00 FA01 5C094 AA03 AA08 AA10 AA43 AA46 AA48 BA03 BA12 BA27 CA19 CA20 CA24 DA13 DB01 DB04 EA04 EA05 EA07 EB02 FA01 FA02 FB01 FB20 GB10 5G435 AA03 AA04 AA17 BB05 CC09KK

Claims (9)

[Claims] 1. A method of manufacturing a display device comprising a pixel electrode and a switching active element for driving the pixel electrode, wherein a light emitting layer is formed in a gap between the pixel electrode and a counter electrode. A step of attaching a light emitting layer forming film having a light emitting layer formed on the film from the light emitting layer side to a substrate having the pixel electrode formed thereon, and (2) a base film side of the light emitting layer forming film The step of irradiating and selectively adhering the light emitting layer to the pixel electrode;
A method for manufacturing a display device, comprising: forming a film on a substrate, and removing the film from the substrate, and (4) forming a counter electrode. 2. The method of manufacturing a display device according to claim 1, wherein the element isolation film is not formed. 3. The method for manufacturing a display device according to claim 1, wherein the device isolation film having a desired pattern shape is formed after forming the light emitting layer. 4. A display device formed by using the method for manufacturing a display device according to claim 1. 5. A display device formed by using the method for manufacturing a display device according to claim 2, wherein an element isolation film is not formed. 6. A display device formed by using the method for manufacturing a display device according to claim 3. 7. A method of manufacturing an OLED display device, wherein the display device according to any one of claims 1 to 5 is an OLED display device. 8. An OLED display device formed by using the method for manufacturing an OLED display device according to claim 7. 9. The OLED display device according to claim 8, wherein the pixel array of the OLED display device is a matrix type array or a delta type array.