METHOD FOR MANUFACTURING ORGANIC EL DISPLAY APPARATUS

TECHNICAL FIELD

The present invention relates to a method for manufacturing an organic EL display apparatus.

BACKGROUND ART Japanese Patent Application Laid-Open No. H08-222371 (Patent Document 1) discloses a laser-used fine processing method as a technique for patterning electrodes, organic layers, etc., of an organic EL display apparatus with a stacked configuration of at least two organic light- emitting elements, each including an organic layer, which contains an emission layer, interposed between two electrodes, into desired shapes.

In Patent Document 1, a fine pattern is formed in an organic EL element with a configuration of substrate/transparent electrode/organic compound layer/metal electrode by selectively removing a part of organic compound layer/metal electrode by means of laser ablation.

In order to manufacture an organic EL display apparatus with a stacked configuration of organic light- emitting elements, each including an organic layer, which contains an emission layer, interposed between two electrodes, it is necessary to deposit a plurality of organic layers and electrode layers on a substrate. Furthermore, in order to drive the respective organic light-emitting elements, it is necessary to pattern each electrode layer, and connect an upper electrode layer to a lower electrode layer or a wiring layer formed in advance on the substrate. In other words, it is necessary to selectively remove the electrode layers and the organic layers . In the case of the configuration of a first organic layer with an electrode layer and a second organic layer deposited thereon, when selectively removing the second organic layer from the electrode layer using laser ablation as in Patent Document 1, ablation occurs not only in the second organic layer, but also in the underlying layer and/or the supporting base material, which may hinder a favorable shape from being obtained as a result of the processing.

DISCLOSURE OF THE INVENTION

Therefore, the present invention provides a method for manufacturing an organic EL display apparatus with a configuration that includes at least first electrodes, a first organic layer, second electrodes, a second organic layer and third electrodes on a supporting base material, in which when selectively removing the organic layers, a wide process margin can be secured, providing an excellent processing stability.

In other words, the present invention provides a method for manufacturing an organic EL display apparatus including a plurality of stacked organic EL elements in a plane thereof, each of the plurality of stacked organic EL elements including at least a first electrode, a first organic layer, a second electrode, a second organic layer and a third electrode on a supporting base material, the method comprising steps of: forming a plurality of first electrodes; forming a first organic layer on the first electrodes and between the adjacent first electrodes; removing a partial region of the first organic layer formed between the adjacent first electrodes via a laser, thereby providing a region in which the first organic layer has been removed; providing a second electrode on the first organic layer and in the region in which the first organic layer has been removed, respectively; forming a second organic layer at least on the second electrodes; removing the second organic layer at least in the region in which the first organic layer has been removed; and providing third electrodes on the second organic layer, wherein the providing a region in which the first organic layer has been removed includes subjecting the first organic layer to laser ablation under a condition not making the supporting base material be subjected to the laser ablation. According to the present invention, the underlying layer and the supporting base material in the regions in which the organic layers are selectively removed are resistant to ablation, and thus, even though the laser intensity is increased, damage to the underlying layer and the supporting base material remains small. Accordingly, the laser intensity margin is expanded, enabling reliable organic layer removal.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a pixel in an organic EL display apparatus according to a first embodiment.

FIG. 2 is a schematic perspective view of an organic EL display apparatus according to a first embodiment.

FIGS. 3A, 3B, 3C, 3D, 3E, 3F and 3G are diagrams illustrating a method for manufacturing an organic EL display apparatus according to a first embodiment.

FIG. 4 is a diagram illustrating an equivalent circuit for an organic EL display apparatus according to a first embodiment.

FIG. 5 is a diagram illustrating a pixel circuit configuration in an organic EL display apparatus according to a first embodiment. FIG. 6 is a schematic cross-sectional view of a pixel in an organic EL display apparatus according to a second embodiment .

FIGS. IA, IB, 1C, IO, 7E and 7F are diagrams illustrating a method for manufacturing an organic EL display apparatus according to a second embodiment.

FIG. 8 is a diagram illustrating an equivalent circuit for an organic EL display apparatus according to a second embodiment.

FIG. 9 is a diagram illustrating an example waveform of an alternate-current voltage of a power supply unit in an organic EL display apparatus according to a second embodiment .

FIG. 10 is a diagram illustrating a pixel circuit configuration in an organic EL display apparatus according to a second embodiment.

FIG. 11 is a schematic cross-sectional view of a pixel in an organic EL display apparatus according to a third embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

Laser ablation refers to a process of applying laser light to a solid to etch the surface of the solid. In the process, when the intensity of the laser light becomes a certain value (threshold value) or more, the laser light is converted into electronic, thermal, photochemical and dynamical (mechanical) energy on the solid surface, and as a result, neutral atoms, molecules, positive/negative ions, radicals, clusters, electrons, light (photons) are explosively ejected, thereby etching the solid surface.

In the present invention, a condition for providing regions in which a first organic layer has been removed by means of laser ablation is determined so as to prevent a supporting base material from being damaged by the laser ablation.

More specifically, the condition for providing the regions in which the first organic layer has been removed by means of laser ablation is a condition that prevents the supporting base material from being damaged by the laser ablation, that is, a condition such as a low energy density, a short irradiation time or a small number of irradiations.

Hereinafter, embodiments of a method for manufacturing an organic EL display apparatus according to the present invention will be described with reference to the drawings .

For the parts not specifically illustrated in the drawings or contained in the present description, techniques widely or publicly known in the relevant technical field are applied. Also, the below-described embodiments are some embodiments of the present invention, and the present invention is not limited to these embodiments .

First, the reference numerals in the drawings will be described. Reference numeral 1 denotes a display region, reference numeral 2 denotes pixels, reference numeral 10 denotes a supporting base material, reference numerals 11a, lib and lie denote first electrodes, reference numeral 12 denotes a first organic layer, reference numerals 13a, 13b and 13c denote second electrodes, reference numeral 14 denotes a second organic layer, and reference numerals 15a, 15b and 15c denote third electrodes.

Reference numeral 16 denotes a third organic layer, reference numeral 21 denotes a fourth electrode, reference numeral 22 denotes a protective layer, reference numeral 23 denotes a power supply unit, reference numeral 24 denotes laser light, reference numeral 30 denotes a supporting base material, reference numeral 31 denotes first electrodes, reference numeral 32 denotes a first organic layer, reference numerals 33a and 33b denote second electrodes, reference numeral 34 denotes a second organic layer, and reference numerals 35a and 35b denote third electrodes.

Reference numeral 36 denotes a third organic layer, reference numeral 41 denotes a fourth electrode, reference numeral 42 denotes a protective layer, reference numeral 43 denotes a power supply unit, reference numeral 44 denotes laser light, reference numeral 50 denotes a supporting base material, reference numerals 51a and 51b denote first electrodes, reference numeral 51c denotes another member, reference numeral 52 denotes a first organic layer, reference numerals 53a and 53b denote second electrodes, and reference numeral 54 denotes a second organic layer. Reference numerals 55a and 55b denote third electrodes, reference numeral 56 denotes a third organic layer, reference numeral 61 denotes a fourth electrode, reference numeral 62 denotes a protective layer, reference numeral 63 denotes a power supply unit, reference numeral 101 denotes a switching TFT, reference numeral 102 denotes a driving TFT, and reference numeral 103 denotes an organic light-emitting element.

Reference numeral 104 denotes a capacitor, reference numeral 105 denotes a gate signal line, reference numeral 106 denotes a source signal line, reference numeral 107 denotes a power supply line, reference numeral 108 denotes a counter electrode, reference numeral Pl denotes a first sub-pixel, reference numeral P2 denotes a second sub-pixel, and reference numeral P3 denotes a third sub-pixel. <First Embodiment>

An organic EL display apparatus manufactured according to the present invention includes a plurality of stacked organic EL elements in a plane thereof, each stacked organic EL element including at least first electrodes, a first organic layer, second electrodes, a second organic layer and third electrodes on a supporting base material. FIG. 1 is a diagram schematically illustrating an example of a detailed cross-sectional structure of one pixel region of an organic EL display apparatus manufactured according to the present embodiment. As illustrated in FIG. 2, a display region 1 of the organic EL display apparatus according to the present embodiment includes a plurality of pixels 2, one of which is illustrated in FIG. 1.

As illustrated in FIG. 1, one pixel includes three sub-pixels Pl to P3 arranged in parallel, each sub-pixel including a stack of three organic EL layers that emit light of different colors, each organic EL layer including an organic layer interposed between electrodes. For each organic layer, any of a single-layer type (organic emission layer) , a double-layer type (organic emission layer/hole injection layer), a three-layer type (electron transport layer/organic emission layer/hole transport layer) , a four- layer type (electron injection layer/organic emission layer/hole transport layer/hole injection layer) , a five- layer type (electron injection layer/electron transport layer/organic emission layer/hole transport layer/hole injection layer) may be used.

The organic EL apparatus in FIG. 1 is a top emission- type organic EL apparatus. FIG. 1 illustrates an insulating substrate 10, which is a supporting base material, first electrodes 11a, lib and lie, a first organic layer 12, second electrodes 13a, 13b and 13c, a second organic layer 14, third electrodes 15a, 15b and 15c, a third organic layer 16 and a fourth electrode 21. Each organic layer according to the present embodiment has a three-layer configuration of electron transport layer/organic emission layer/hole transport layer. The second electrodes 13 function as upper electrodes of the first organic layer 12 and also function as lower electrodes of the second organic layer 14. The third electrodes 15 function as upper electrodes of the second organic layer 14 and also function as lower electrodes of the third organic layer 16.

Hereinafter, a method for manufacturing the organic EL display apparatus illustrated in FIG. 1 will be described with reference to FIGS. 3A to 3G. The insulating substrate 10, on which switching elements such as TFTs are formed as necessary, has its surface covered with a material having insulating properties, such as glass, quartz, acrylic resin or polyimide resin. However, it is desirable that the surface be covered with an inorganic material. A plurality of the first electrodes 11a to lie are formed in the pixel region of the substrate. Although the first electrodes 11 may be of, e.g., a conductive organic resin film, it can also be of a light-reflective member, for example, a material such as Cr, Al, Ag, Au or Pt. This is because as the member has a higher reflectance, the efficiency of light ejection can be more enhanced. A first organic layer 12 is deposited on the first electrodes 11 and between the adjacent first electrodes 11 on such substrate using a known means (FIG. 3A) .

Here, the organic layer contains an organic light- emitting material, and furthermore, may have a stacked configuration including an organic light-emitting material together with, e.g., a hole injection material, an electron injection material, a hole transport material and an electron transport material. The range of color choices can be expanded by, e.g., doping an organic light-emitting material into a hole injection material or a hole transport material, or doping an organic light-emitting material into an electron injection material or an electron transport material. Furthermore, the organic layer can be an amorphous film from the perspective of luminance efficiency.

Examples of organic light-emitting materials for respective colors include, but not limited to, triarylamine derivatives, stilbene derivatives, polyarylenes, aromatic condensed polycyclic compounds, aromatic heterocyclic compounds, aromatic condensed heterocyclic compounds, and metal complex compounds, and single or complex oligomers thereof.

Each organic layer may be a layer having a single function of each of hole injection, hole transport, electron injection and electron transport, or may also be a layer having a composite function thereof.

The organic layer can have a film thickness of around 0.05 to 0.3 μm, preferably, around 0.05 to 0.15 μm.

Examples of the hole injection and transport materials include, but not limited to, phthalocyanine compounds, triarylamine compounds, conductive polymers, perylene compounds, and Eu complexes.

Examples of the electron injection and transport materials include Alq3, in which the trimer of 8- hydroxyquinoline is coordinated to aluminum, azomethine zinc complexes, distyrylbiphenyl derivatives. Next, partial regions of the first organic layer 12 formed between the adjacent first electrodes 11, that is, the regions of the first organic layer 12 in which contact holes are to be formed and contact holes are formed later are removed (FIG. 3B) . For the processing method, laser processing is employed, and in the present embodiment, an excimer laser with a wavelength of 248 nm is employed. The excimer laser is formed into a planar light source and the substrate is irradiated with the laser in a predetermined pattern via a mask that allows the light to pass through the parts to be processed. The first organic layer 12 can be removed even with an output per unit area of 40 mJ/cm ² or less, while the insulating substrate 10 is not removed even with an output per unit area of 200 mJ/cm ² . Accordingly, the removal processing may be performed with a laser output of 40 to 200 mJ/cm ² and also with a necessary number of irradiations selected according to the film thickness of the organic layer. The boring diameter is preferably 2 to 15 μm. Consequently, stable laser removal that enables reduction of an effect, such as ablation, on the insulating substrate 10 can be performed.

Next, a film of a transparent electrode is formed and patterned to form second electrodes 13a, 13b, and 13c on the first organic layer 12 and in the regions in which the first organic layer 12 has been removed. Here, the first electrodes lib and lie, and the second electrodes 13b and 13c are connected, respectively, via contact holes. For the material for the second electrodes 13, a highly- transrnissive material, for example, a transparent conductive film of, e.g., ITO, IZO or ZnO, or an organic conductive film of, e.g., polyacetylene, is preferred. Furthermore, a semi-transmissive film formed by depositing a metal such as Ag or Al in the thickness of around 10 to 30 ran may be used. For the patterning method, laser processing can be employed, but the pattern may also be formed by heating an electrode material to perform vapor deposition using a metal mask. Also, the pattern may be transferred by performing laser ablation with a substrate, on which an electrode material is formed, facing the supporting base material 10.

Next, a second organic layer 14 is deposited on the second electrodes 13 and between the adjacent second electrodes 13 using a known means (FIG. 3C) .

Next, partial regions of the second organic layer 14 that include the regions in which the first organic layer 12 has been removed are removed by means of a laser 24 (FIG. 3D) . Here, the width in the in-plane direction of the regions in which the second organic layer 14 has been removed can be equal to or smaller than the width in the in-plane direction of the regions in which the first organic layer 12 has been removed.

Next, with a method similar to the above-described method, formation of third electrodes 15a, 15b and 15c, and a third organic layer 16 on the second organic layer 14 (FIG. 3E) and laser removal of the third organic layer 16 (FIG. 3F) are sequentially performed.

Next, a fourth electrode 21 is formed by, e.g., sputtering. For the materials for the third electrodes 15 and the fourth electrode 21, a highly-transmissive material is preferred as is the case with the material for the second electrodes 13.

Furthermore, a film of silicon nitride oxide is formed as a protective layer 22, and is connected to a power supply unit 23, providing a display apparatus (FIG. 3G) .

In the present embodiment, in the process of removing an organic layer by means of a laser in FIGS. 3B, 3D and 3F, no other organic layers exist below the uppermost organic layer, enabling stable laser removal that enables reduction of an effect, such as ablation, on the underlayer.

FIG. 4 illustrates an equivalent circuit for an organic EL display apparatus configured as described above. In the first sub-pixel Pl, the second organic layer 14 and the third organic layer 16 are bypassed, thereby a voltage being applied to the first organic layer 12. Similarly, in the second sub-pixel P2, a voltage is applied to the second organic layer 14, and in the third sub-pixel P3, a voltage is applied to the third organic layer 16.

Accordingly, a voltage is applied to only one organic layer, and the voltage of the power supply unit 23 may be a voltage for one layer, that is, around 5 V. Furthermore, it is unnecessary to provide the organic layers 12, 14 and 16 with colors different from one another, enabling provision of a high aperture ratio.

FIG. 5 illustrates a pixel circuit configuration of the organic EL display apparatus according to the present embodiment. Each sub-pixel includes a switching TFT 101, a driving TFT 102, an organic light-emitting element 103 and a capacitor 104.

Here, the gate electrode of the switching TFT 101 is connected to a gate signal line 105. Also, the source region of the switching TFT 101 is connected to a source signal line 106, and the drain region is connected to the gate electrode of the driving TFT 102. Also, the source region of the driving TFT 102 is connected to a power supply line 107, and the drain region is connected to one electrode of the organic EL element 103 (i.e., connected to the first electrode 11a in the sub-pixel Pl, and also connected to the first electrodes lib and lie in the sub- pixels P2 and P3, respectively) . The other electrode of the organic light-emitting element 103 is connected to a counter electrode 108 (the fourth electrode 21) . The capacitor 104 is configured so that electrodes thereof are connected to the gate electrode of the driving TFT 102 and the power supply line 107, respectively. As described above, the driving TFT 102 and the organic EL element 103 are connected in series, thereby current flowing in the organic EL element 103 being controlled by the driving TFT 102.

<Second Embodiment>

FIG. 6 is a diagram schematically illustrating a cross-section of an organic EL display apparatus according to the present embodiment. The organic EL apparatus in FIG. 6 is a top emission- type organic EL apparatus. FIG. 6 illustrates an insulating substrate 30, which is similar to that in the first embodiment, first electrodes 31, a first organic emission layer 32, second electrodes 33a and 33b, a second organic layer 34, third electrodes 35a and 35b, a third organic layer 36 and a fourth electrode 41. Each organic layer according to the present embodiment has a three-layer configuration of electron transport layer/organic emission layer/hole transport layer. The second electrodes 33 function as upper electrodes of the first organic layer 32, and also function as lower electrodes of the second organic layer 34. The third electrodes 35 function as upper electrodes of the second organic layer 34, and also function as lower electrodes of the third organic layer 36. Numeral 43 denotes a power supply unit.

In the organic EL apparatus in FIG. 6, one pixel includes a first sub-pixel Pl and a second sub-pixel P2.

The first electrodes 31 are formed in the pixel region of the insulating substrate 30 on which switching elements such as TFTs are formed as necessary. The first electrodes 31a and 31b are connected in the substrate-face direction, and thus, electrically communicated with each other. The first electrodes 31 and the fourth electrode 41 are common electrodes, and the first electrodes 31 and the fourth electrode 41 of the adjacent sub-pixels are connected, respectively. Furthermore, the first electrodes 31 and the fourth electrode 41 are connected, and the point of the connection may be either within the display region or outside the display region, and in any case, the same voltage is supplied to the first electrodes 31 and the fourth electrode 41. The second electrode 33a and the third electrode 35a in the first sub-pixel are connected via a contact hole formed by laser processing, and the first electrode 31b and the second electrode 33b in the second sub-pixel are connected via a contact hole formed by laser processing. Hereinafter, a method for manufacturing the organic EL display apparatus illustrated in FIG. 6 will be described. The materials for the organic layers and electrodes are the same as those of the first embodiment.

Switching elements such as TFTs are formed on the insulating substrate 30 as necessary, and a plurality of first electrodes 31a and 31b are formed in the pixel region of the insulating substrate 30.

A first organic layer 32 is deposited on the first electrodes 31 and between the adjacent first electrodes 31 on such substrate using a known means (FIG. 7A) .

Next, formation of contact holes and removal of the organic layer in the regions in which contact holes are formed later are performed. The processing methods are both similar to those of the first embodiment (FIG. 7B) .

Next, a film of a transparent electrode is formed and patterned to form second electrodes 33a and 33b on the first organic layer 32 and in the regions in which the first organic layer 32 has been removed. Here, the first electrode 31b and the second electrode 33b are connected via a contact hole.

Next, with a method similar to that of the first embodiment, a second organic layer 34 is formed (FIG. 7C) , removal of the second organic layer 34 via a laser 44 (FIG. 7D) , formation of third electrodes 35a and 35b and a third organic layer 36, and formation of a fourth electrode 41 are sequentially performed (FIG. 7E) . Next, a film of silicon nitride oxide is formed as a protective layer 42, and is connected to a power supply unit 43, thereby providing a display apparatus (FIG. 7F) . In the present embodiment, in the process of removing an organic layer via a laser in FIGS. 7B and 7D), no other organic layers exist below the uppermost organic layer, enabling stable laser removal that enables reduction of an effect on the underlying material.

FIG. 8 illustrates an equivalent circuit for the organic EL display apparatus configured as described above.

Next, a method for driving an organic EL apparatus with the above-described structure will be described with reference to FIG. 9. FIG. 9 is a diagram illustrating an example of the waveform of a voltage applied between electrodes of the organic EL apparatus by the power supply unit 43.

In order to make the first organic layer 32 and the second organic layer 34 emit light, a negative voltage is applied by the power supply unit 43 to the third electrodes 35a and 35b, and a positive voltage is applied by the power supply unit 43 to the common electrodes (the first electrodes 31 and the fourth electrode 41) . Consequently, electrons are injected into the first organic layer 32 and the second organic layer 34 from the second electrodes 33a and the third electrodes 35b, as well as holes being injected into the first organic layer 32 and the second organic layer 34 from the first electrodes 31a and the second electrodes 33b, and light emissions occur when organic molecules excited by recombination of the electrons and holes relax to the ground state. Then, the emitted light is ejected from the protective layer 42 side. The third organic layer 36 does not emit light because a reverse voltage is applied to the third organic layer 36.

Next, in order to make the third organic layer 36 emit light, a positive voltage is applied by the power supply unit 43 to the third electrodes 35a and 35b, and a negative voltage is applied by the power supply unit 43 to the first electrodes 31 and the fourth electrode 41. Consequently, electrons are injected into the third organic layer 36 from the fourth electrode 41, as well as holes being injected into the third organic layer 36 from the pixel electrodes (third electrodes) 35a and 35b, and light emissions occur when organic molecules excited by recombination of the electrons and holes relax to the ground state. Then, the emitted light is ejected from the protective layer 42 side. Here, the first organic layer 32 and the second organic layer 34 do not emit light because a reverse voltage is applied to the first organic layer 32 and the second organic layer 34. Also, in order to make the first organic layer 32, the second organic layer 34 and the third organic layer 36 emit light to emit light of a mixed color, as illustrated in FIG. 9, an alternate current is applied by the power supply unit 43 to the third electrodes 35a and 35b and the common electrodes (the first electrodes 31 and the fourth electrode 41) to perform alternate-current driving. More specifically, the power supply unit 43 controls the switching of a voltage between the positive side and the negative side with a cycle of a degree that cannot be perceived by humans, for example, with a frequency of around 60 Hz or higher, thereby controlling the respective emitted-light luminances. Consequently, light of an arbitrary color, which is a mixture of the colors of light emitted from the first organic layer 32 and the second organic layer 34, and the color of light emitted from the third organic layer 36, can be expressed. In the above-described organic EL display apparatus, a voltage is applied to only one organic EL layer, and the voltage of the power supply unit 43 may be a voltage for one layer, that is, around 5 V. Furthermore, it is unnecessary to provide the organic layers 32, 34 and 36 with colors different from one another, and only two sub- pixels, which are fewer than those in the first embodiment, are provided, enabling provision of a higher aperture ratio.

FIG. 10 illustrates a pixel circuit configuration of the organic EL display apparatus according to the present embodiment. Each sub-pixel includes a switching TFT 101, a driving TFT 102, an organic light-emitting element 103 and a capacitor 104.

Here, the gate electrode of the switching TFT 101 is connected to a gate signal line 105. Also, the source region of the switching TFT 101 is connected to a source signal line 106, and the drain region is connected to the gate electrode of the driving TFT 102. Also, the source region of the driving TFT 102 is connected to a power supply line 107, and the drain region is connected to one electrode of the organic EL element 103 (i.e., connected to the third electrode 35a in the sub-pixel Pl, and also connected to the third electrode 35b in the sub-pixel P2) . The other electrode of the organic light-emitting element

103 is connected to a counter electrode 108 (the first electrode 31 and the fourth electrode 41) . The capacitor

104 formed so that electrodes thereof are connected to the gate electrode of the driving TFT 102 and GND, respectively.

As described above, the driving TFT 102 and the organic EL element 103 are connected in series, thereby current flowing in the organic EL element 103 being controlled by the driving TFT 102. <Third Embodiment>

FIG. 11 is a diagram schematically illustrating a cross-section of an organic EL display apparatus manufactured according to the present embodiment. Numeral 63 denotes a power supply unit. In this embodiment, a film of a first electrode 51 is formed on an insulating substrate 50, which is similar to that in the first embodiment, and then, patterned so that another member 51c remains between first electrodes 51a and 51b, the another member 51c being insulated from the first electrodes 51a and 51b.

The another member 51c functions as a reflective layer during excimer laser processing, which is performed later. Accordingly, it is desirable that the another member 51c have a reflectance of no less than 90% for excimer laser light with a wavelength of 248 nm, and also the another member 51c may preferably be constituted of the same material as that of the first electrode. Also, the another member 51c can be a member that can be removed by a laser with an higher energy density, a longer irradiation time or a larger number of irradiations relative to a laser removal processing condition for the first organic layer 52 and the second organic layer 54. Existence of the another member 51c makes laser light be reflected by the another member 51c even when the laser light intensity is large, causing almost no effect on the underlayer, enabling more stable processing to be performed. Consequently, the organic layers can reliably be removed.

Although description of the process subsequent to the patterning of the first electrode 51 will be omitted because it is similar to that in the second embodiment, a processing condition for the first organic layer 52 and the second organic layer 54 will be described below. For processing, an excimer laser with a wavelength of 248 nm is used. The laser is formed into a planar light source and the substrate is irradiated with the laser in a predetermined pattern via a mask that allows the light to pass through the parts to be processed. The first organic layer 52 and the second organic layer 54 can be removed even with an output per unit area of 40 mJ/cm ² or less, while the another member 51c is not removed even with an output per unit area of 500 mJ/cm ² . Accordingly, the removal processing can be performed with a laser output of 40 to 500 mJ/cm ² and also with a necessary number of irradiations selected according to the respective organic layer film thicknesses. For both organic layers, the bore diameter can be 2 to 15 μm.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions . This application claims the benefit of Japanese

Patent Application No. 2008-170290, filed June 30, 2008, which is hereby incorporated by reference in its entirety.