JP2004219928A - Method for manufacturing electrode for display panel - Google Patents

Abstract

There is no short-circuit defect between electrodes in a substrate, and no scattered matter (particles) due to laser beam irradiation, which is a cause of short-circuiting between electrodes facing each other when a display panel is formed by a conventional repair method, remains. Such an electrode forming method is provided.
A resist film having a predetermined shape is formed on an electrode film provided on a substrate, the resist film is used as an etching resistant film, and the electrode film exposed from an opening of the resist film is etched. A method of manufacturing an electrode for a display panel by a photo-etching method, in which an electrode having a shape corresponding to the resist film having a predetermined shape is formed by removing a film, washing, and the like, wherein the resist film having the predetermined shape is formed. After the step and before the etching step, a removing step of removing a pattern defect portion of the resist film that causes a short-circuit defect of the electrode is performed. The removing step is for removing a pattern defect portion of the resist film by irradiating a laser beam.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an electrode for a display panel such as an organic EL display panel and an LCD display panel.
[0002]
[Prior art]
In recent years, by using electroluminescence (hereinafter, referred to as organic EL) of an organic compound material that emits light by current injection, a plurality of organic EL elements each including a light emitting layer formed of a thin film of such an organic EL material are arranged in a matrix. Organic EL display panels have come to be used as mobile terminals and in-vehicle panels.
In the future, it will be used for the display of personal computers.
An organic EL element using an organic compound material as a light emitter has a wider viewing angle, better contrast, better visibility than a liquid crystal element, and can be thinner and lighter because a backlight is not required. It is also advantageous in terms of speed and quick response.
Since they are all solid, they are resistant to vibration and have a wide operating temperature range.
[0003]
The structure of an organic EL element is basically a structure in which an organic compound-containing (EL layer) is sandwiched between a pair of electrodes of an anode and a cathode. It is based on a laminated structure of “light emitting layer / cathode electrode”. (Japanese Patent No. 1526026)
The organic EL element emits light by applying an electric field between the electrodes and passing a current through the EL layer.
When an organic EL element is used as a panel for a display, it is roughly classified into a passive matrix type and an active matrix type according to an electrode configuration and a driving method as in the case of an LCD. In such a panel, an organic EL element is used. As a method of achieving colorization, in addition to a three-color juxtaposition method in which the most basic three-color organic EL materials of R, G, and B are precisely arranged for each pixel of a display device, a white light emitting layer and an R , G, B color filters (also referred to as CF), or a blue light emitting layer and R, G fluorescence conversion dye filters, such as a panelized organic EL panel structure whose schematic cross section is shown in FIG. There is a CCM (Color Changing Medium) system that can combine the above.
For example, an organic EL display panel of the CCM type has a structure shown in FIG. 2, and a barrier layer 260 for protecting a light-emitting layer having low moisture resistance and low solvent resistance under a transparent electrode 270; An insulating layer 250 and an OC layer (overcoat layer) 240 are provided.
[0004]
By the way, when an organic EL element is formed into a panel for a display to produce an organic EL panel structure, usually, an organic EL light emitting layer having a color filter layer and a transparent electrode formed on a transparent glass substrate is not provided in advance. A panel in a state is formed using a photolithography process or the like, and a light emitting layer or the like is disposed by vapor deposition or the like on a panel in which the organic EL light emitting layer thus formed is not disposed. The display panel is manufactured by sealing.
However, when a transparent electrode is formed by performing a photolithography process or the like, a positive resist is generally used, so that a short defect occurs in the transparent electrode due to unnecessary resist residue or a foreign matter attached to the resist film. It has become.
In processing such a transparent electrode, as shown in FIG. 3, a resist film 330 is formed on an electrode film 320 (FIG. 3B) disposed on a substrate 310 (FIG. 3A). (FIG. 3 (c)), development through an exposure step (FIG. 3 (d)) to form a pattern of a resist film 330 having a predetermined shape (FIG. 3 (e)), and then the pattern of the resist film 330 Is used as an etching resistant film, the electrode film 320 exposed from the opening 337 of the resist film 330 is etched to form an electrode 320A (FIG. 3F), and the resist film 330 is removed, and a series of cleaning is performed. Was performed in the process.
Incidentally, such a processing method is generally referred to as a photoetching method or a photoetching method.
[0005]
However, when the electrodes are processed in this manner, a short defect 475 between the electrodes often remains after the processing, as shown in FIG. 4, and it is necessary to correct such a short defect.
FIG. 4 shows a case where the transparent electrode 470 for the display panel shown in FIG. 2 is formed.
For this reason, after processing, as shown in FIG. 5A, the short defect portion 475 is irradiated with a laser beam, and the electrode film at that portion is removed, thereby correcting the short defect portion of the transparent electrode 470. However, in this correction method, as shown in FIG. 5C, scattered matter (also referred to as particles) 490 due to laser light irradiation remains on the transparent electrode 470. That is, when the scattered matter is large, as shown in FIG. 6, when the panel is formed, a short circuit occurs between the transparent electrode 570 (equivalent to 470 in FIG. 5) and the counter electrode (negative electrode) 575 of the organic EL display panel. There is a problem that occurs.
Further, as shown in FIG. 5C, the barrier layer 460 may be damaged depending on the laser light irradiation conditions, which has been a problem.
5 is a diagram showing a cross section taken along line B1-B2 of FIG. 4, FIG. 4 is a diagram viewed from the D1 side of FIG. 5, and FIG. 5C is an enlarged view of D2 of FIG. 5B. FIG.
[0006]
In electrode processing for LCD (liquid crystal display) panels having a structure in which a predetermined gap (referred to as a cell gap) is maintained between a CF (color filter) substrate and a TFT substrate and a liquid crystal is injected between the substrates, a cell has recently been used. When the gap is apt to be small and the electrode is formed by the photo-etching method shown in FIG. 3 and then the short-circuit defect portion of the electrode is removed by laser beam irradiation, a short-circuit occurs between the substrates. There's a problem.
[0007]
[Problems to be solved by the invention]
As described above, in processing an electrode for an organic EL display panel or an electrode for an LCD panel, there is no short-circuit defect between the electrodes in the substrate, and there is no scattering due to laser beam irradiation for correction. There has been a demand for a method of forming electrodes that does not cause a short circuit between electrodes facing each other when a display panel is formed.
The present invention responds to this problem, and has no short-circuit defect between electrodes in a substrate, and causes a short-circuit between opposing electrodes when a display panel is formed by a conventional repair method. An object of the present invention is to provide a method for forming an electrode such that flying particles (particles) do not remain.
[0008]
[Means for Solving the Problems]
In the method for manufacturing an electrode for a display panel of the present invention, a resist film having a predetermined shape is formed on an electrode film provided on a substrate, and the resist film is exposed from an opening of the resist film as an etching resistant film. Etching the electrode film, further removing the resist film, washing and the like, forming an electrode having a shape corresponding to the predetermined shape of the resist film, a method for producing an electrode for a display panel by a photo-etching method, After the step of forming the resist film having the predetermined shape, before the step of etching, a removing step of removing a pattern defect portion of the resist film that causes a short-circuit defect of the electrode is performed. .
In the above, the removing step is characterized by removing a pattern defect portion of the resist film by irradiating a laser beam, and the laser beam is a YAG laser beam. is there.
Further, in the above, there is provided a method of manufacturing an electrode for an organic EL display panel.
In the above, the electrode film is an ITO film.
The removal by laser beam irradiation is preferably performed only on the pattern defect portion of the resist film, but the electrode film may be slightly removed.
[0009]
[Action]
The method for manufacturing an electrode for a display panel according to the present invention, by adopting such a structure, eliminates a short-circuit defect between electrodes in a substrate, and furthermore, a gap between electrodes facing each other when a display panel is formed by a conventional repair method. It is possible to provide an electrode forming method that does not leave scattered particles (particles) due to laser beam irradiation, which is a cause of short circuit.
Further, it is possible to provide an electrode forming method that does not damage the lower layer of the electrode (corresponding to the barrier layer 460 or the like in FIG. 5) by irradiating a laser beam such as the conventional YAG laser shown in FIG.
Specifically, a resist film having a predetermined shape is formed on the electrode film provided on the substrate, the resist film is used as an etching resistant film, and the electrode film exposed from the opening of the resist film is etched. A method of manufacturing an electrode for a display panel by a photo-etching method, wherein a resist film is removed, washed, and the like, and an electrode having a shape corresponding to the predetermined shape of the resist film is formed. This is achieved by performing a removing step of removing a pattern defect portion of the resist film that causes a short-circuit defect of the electrode after the step of performing the etching and before the step of etching.
As a removal step, a method of removing a pattern defect portion of a resist film by irradiating a laser beam may be mentioned as a practical one.
In a step of removing a pattern defect portion of a resist film by laser light irradiation, scattering objects (also referred to as particles) are usually generated at the time of laser irradiation. Therefore, cleaning is performed as necessary after the laser irradiation.
Examples of the scattered matter by laser light irradiation include foreign matter scattered matter, resist film scattered matter, and electrode film scattered matter, and all of them can be removed by a series of processes after an etching step after laser irradiation.
Examples of the laser light include, but are not limited to, a YAG laser light from the viewpoint that the oscillator is compact, easy to implement, and easy to handle.
Note that the removing step is not limited to the laser beam irradiation.
Other simple removal methods include removal by cutting or polishing. In this case, too, cleaning is performed after cutting or polishing, if necessary.
[0010]
In the case of a method for manufacturing an electrode for an organic EL display panel, it is possible to eliminate the occurrence of damage to the barrier layer below the electrode film in the conventional repair method, and to face the display panel in the conventional repair method. This is particularly effective in that scattered matter (particles) due to laser beam irradiation, which is a cause of short-circuit between electrodes, does not remain.
Of course, the present invention is not limited to a method for manufacturing an electrode for an organic EL display panel.
In recent years, the cell gap has been reduced in electrode processing for LCD panels having a structure in which a predetermined gap (referred to as a cell gap) is maintained between a CF (color filter) substrate and a TFT substrate, and a liquid crystal is injected between the substrates. Prone and equally effective.
Examples of the electrode film include a transparent electrode film.
Examples of the transparent electrode film include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), ZnO, SnO ₂ , and In ₂ O _3. In general, ITO is used.
In addition, as the laser light, a YAG laser light is cited from the viewpoint that the oscillator is compact, easy to implement, and easy to handle, but is not limited thereto.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
One example of an embodiment of a method for manufacturing an electrode for a display panel according to the present invention will be described with reference to the drawings.
FIG. 1 is a process cross-sectional view of one example of an embodiment of a method for manufacturing an electrode for a display panel of the present invention.
In FIG. 1, 110 is a substrate, 120 is an electrode film, 120A is an electrode, 130 is a resist film, 135 is a pattern defect (of resist), 136 is a repaired portion, 137 is an opening, 140 is a photomask, and 150 is exposure Reference numeral 160 denotes a laser beam (YAG laser beam).
The method of manufacturing an electrode for a display panel of this example is a method of manufacturing a transparent electrode made of ITO in a CCM panel for a CCM type organic EL panel before a light emitting layer is provided, as shown in FIG.
Then, a resist film 130 having a predetermined shape is formed on the electrode film 120 provided on the substrate 110 (corresponding to the barrier layer 260 in FIG. 2), and the resist film 130 is used as an etching-resistant film. A manufacturing method by photoetching, in which the electrode film 120 exposed from the opening of 130 is etched, and the resist film 130 is further removed and washed to form an electrode 120A having a shape corresponding to the predetermined shape of the resist film 130. And a removing step of irradiating a YAG laser beam to remove a pattern defect portion of the resist film that causes a short-circuit defect of the electrode after the step of forming the resist film having the predetermined shape and before the step of etching. Is what you do.
This will be further described with reference to FIG.
First, a substrate 110 on which a CF layer, a CCM layer, an overcoat layer, an insulating layer, and a barrier layer are sequentially provided on a glass substrate is prepared (FIG. 1A), and a barrier layer (FIG. On the entire surface of the electrode film 120, a photosensitive resist is applied and dried (see FIG. 1B). (Fig. 1 (c))
As the photosensitive resist, a positive resist is usually used, and a resist having desired resolution and good processability is preferable, but is not particularly limited.
Next, using a photomask 140 corresponding to the shape of the electrode to be formed, a predetermined region of the photosensitive resist film 130 is exposed (FIG. 1D), developed, and inspected to determine the pattern of the resist film 130 by inspection. The short defect portion 135 is grasped. (Fig. 1 (e))
FIG. 1E is a cross section including a short defect portion in a state after development.
Although the inspection method is not shown, the short defect portion 135 of the pattern of the remaining resist film 130 is extracted in a state after the development, whereby the position of the short defect portion 135 is grasped.
As an inspection method, for example, a method of extracting a short defect portion by a visual inspection using reflected light can be cited. In this case, the defect position can be grasped by marking the defect position on the glass substrate surface.
Alternatively, there is a method in which a substrate after development is placed on an XY stage, the entire surface is scanned with reflected light and / or transmitted light to extract defects, and the position is grasped by automatic inspection.
[0012]
Next, the irradiation size and the output are adjusted by a laser beam irradiation device, and the laser beam is irradiated on the short defect portion 135 of the pattern of the resist film 130 (FIG. 1 (f)), and the short defect portion of the pattern of the resist film is formed. A correction to remove 135 is made. (Fig. 1 (g))
As the laser light to be irradiated, it is preferable that the resist film 130 can be removed and the electrode film 120 is not removed. In some cases, the electrode film 120 may be slightly removed. It is more preferable to grasp the wavelength and output condition of the laser beam used for the test in advance by a test or the like.
As the laser light, the fourth harmonic (266 nm) of a YAG laser or the like is used, but the laser light is not limited to this.
By observing the corrected portion 136 on a monitor under magnification, removal of the resist film 130 can be confirmed.
Next, using the resist film 130 as an etching resistant mask, the electrode film 120 exposed from the opening 137 of the resist film 130 is etched to form an electrode 120A (FIG. 1 (h)). The electrode 120A is formed on the barrier layer (equivalent to 260 in FIG. 2) of the substrate 110 by removing with a liquid (FIG. 1 (i)).
In the correction by laser light irradiation, scattered matter (particles) is generated, and the scattered matter (particles) is removed in subsequent steps such as etching and resist removal.
In the method of the present example, the generated foreign particles (particles) are corrected by laser light irradiation, and the generated foreign particles (particles) are removed in subsequent steps such as etching and resist removal. Therefore, when the display panel is formed, the EL layer caused by the foreign particles is used. It is possible to supply a high-quality organic EL panel that does not have the problem of destruction and deterioration of the service life.
[0013]
This example is a method of manufacturing a transparent electrode made of ITO in a CCM panel before a light emitting layer is provided for an organic EL panel of a CCM method. It goes without saying that the method for manufacturing an electrode for a display panel of the invention can be applied.
Of course, the present invention can be applied to a case where the transparent electrode is other than ITO.
[0014]
【The invention's effect】
The present invention, as described above, has no short-circuit defect between electrodes in a substrate, and is a scattered object due to laser beam irradiation, which is a cause of short-circuiting between opposed electrodes when a display panel is formed by a conventional repair method. It has become possible to provide an electrode forming method that does not leave (particles).
Further, it has become possible to provide an electrode forming method which does not damage the lower layer of the electrode due to irradiation with a laser beam such as a conventional YAG laser.
In particular, in the case where the short defect portion of the pattern of the resist film is removed by laser light irradiation, scattered foreign particles (particles) generated by the modification of the resist film are removed in subsequent steps such as etching and resist removal. When a panel is formed, it is possible to supply a high-quality organic EL panel in which destruction of the EL layer and deterioration of life due to scattering foreign particles (particles) are suppressed.
Of course, in this case, there is an advantage that a dedicated cleaning device is not required.
The present invention is applicable to all display panels other than organic EL and LCD.
[Brief description of the drawings]
FIG. 1 is a process cross-sectional view of one example of an embodiment of a method for manufacturing an electrode for a display panel of the present invention.
FIG. 2 is a sectional view of a CCM type organic EL panel structure.
FIG. 3 is a process sectional view of a conventional transparent electrode processing method.
FIG. 4 is a diagram showing a state after electrode processing in which a short defect between electrodes remains. FIG. 5 is a diagram for explaining a conventional correction of a short defect portion between electrodes and a problem.
FIG. 6 is a diagram for explaining a problem in a display panel of a scattered foreign matter generated by correction by laser light irradiation in the related art.
[Explanation of symbols]
110 substrate 120 electrode film 120A electrode 130 resist film 135 pattern defect (resist) 136 repaired part 137 opening 140 photomask 150 exposure light 160 laser light (YAG laser light)
210 Glass substrate 220 CF layer (also called color filter layer)
230 CCM layer 240 OC layer (also called overcoat layer)
250 Insulating layer 260 Barrier layer 270 Transparent electrode (positive electrode)
275 electrode (negative electrode)
280 light emitting layer 285 barrier 310 substrate 320 electrode film 320A electrode 330 resist film 337 opening 340 photomask 350 exposure light 410 glass substrate 420 CF layer (also called color filter layer)
430 CCM layer 440 OC layer (also called overcoat layer)
450 Insulating layer 460 Barrier layer 470 Transparent electrode (positive electrode)
475 defective part (also called short defective part)
476 Defect correction part 477 Damaged part 480 YAG laser beam 490 Scattered foreign matter (also called particle)

Claims (5)

A resist film having a predetermined shape is formed on the electrode film provided on the substrate, the resist film is used as an etching-resistant film, and the electrode film exposed from the opening of the resist film is etched. Performing washing and the like, forming an electrode having a shape corresponding to the predetermined shape of the resist film, a method of manufacturing an electrode for a display panel by a photo-etching method, after the step of forming the predetermined shape of the resist film, A method for manufacturing an electrode for a display panel, wherein a removing step of removing a pattern defect portion of a resist film that causes a short-circuit defect of the electrode is performed before the etching step. 2. The method for manufacturing an electrode for a display panel according to claim 1, wherein the removing step removes a pattern defect portion of the resist film by irradiating a laser beam. 3. The method for manufacturing an electrode for a display panel according to claim 2, wherein the laser light is a YAG laser light. 4. The method for producing an electrode for a display panel according to claim 1, which is a method for producing an electrode for an organic EL display panel. 5. The method for manufacturing an electrode for a display panel according to claim 1, wherein the electrode film is an ITO film.

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