JP4282798B2 - EL display panel and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an EL display panel and a manufacturing method thereof, and more particularly to a method of manufacturing an organic EL element by forming a predetermined pattern on a glass substrate using a mask.
[0002]
[Prior art]
An example of a pattern forming element in which a predetermined pattern is formed on a substrate is an organic EL element. A perspective view of an EL display panel 25 using organic EL elements is shown in FIG. In the EL display panel 25, a plurality of strip-shaped transparent electrodes 17 are arranged on the glass substrate 2 along the arrow 93 direction. A plurality of strip-shaped organic layers 12 are arranged on the transparent electrode 17 along the arrow 94 direction. Further, a plurality of strip-shaped upper electrodes 13 are disposed on each organic layer 12 so as to overlap each other.
[0003]
If a voltage is applied to such an EL display panel 25 by selecting the predetermined transparent electrode 17 and the predetermined upper electrode 13, the EL display panel 25 is positioned at the intersection of the selected transparent electrode 17 and the upper electrode 13. The organic layer 12 emits light. Therefore, desired display can be performed using the EL display panel 25 by controlling selection of the transparent electrode 17 and the upper electrode 13.
[0004]
As a technique for forming the pattern, there is a technique using a photoresist as a mask. However, when this method is adopted, there arises a disadvantage that the organic layer 12 is peeled off at the same time in the step of removing the resist. For this reason, it is necessary to leave the resist without removing it.
[0005]
However, when manufacturing a color display, for example, different elements (elements having different emission colors) must be formed in the horizontal direction sequentially as the organic layer 12 arranged in the direction of the arrow 94. If the organic layer 12 is formed using the photoresist as a mask, the photoresist once formed cannot be removed, and thus different elements cannot be formed sequentially in the horizontal direction.
[0006]
For this reason, generally, the pattern of the organic layer 12 and the upper electrode 13 is formed on the glass substrate 2 by a vapor deposition technique using a shadow mask. As a shadow mask, an opening is formed in the film so as to form a predetermined pattern, and evaporated atoms are given through the film mask to form a pattern on the glass substrate 2.
[0007]
As for the transparent electrode 17 formed on the glass substrate 2, the transparent electrode 17 can be formed by etching using a photoresist. That is, since the lower portion of the transparent electrode 17 is not an organic layer, the photoresist can be removed after the transparent electrode 17 is formed. Therefore, there is no problem even if an etching method using a photoresist is employed.
[0008]
As shown in FIG. 5A, etching is performed using the photoresist 21 as a mask to obtain a transparent electrode 17 having a predetermined pattern. When isotropic etching is performed, the etching proceeds isotropically in the vertical and horizontal directions, so that the etching also proceeds under the photoresist 21 to cause an undercut and the side surface 18 is sharp. It is formed as an inclined slope. After the transparent electrode 17 shown in FIG. 5A is formed, the photoresist 21 is removed, and the organic layer 12 and the upper electrode 13 shown in FIG. 5B are formed by a vapor deposition technique.
[0009]
[Problems to be solved by the invention]
The conventional pattern forming element manufacturing apparatus and method have the following problems. When the pattern of the organic layer 12 and the upper electrode 13 is formed by the vapor deposition technique using a shadow mask, it is necessary to open a predetermined pattern in advance in the film mask itself.
[0010]
However, etching on a film mask generally results in an error of about 10% to 15% of the film thickness. That is, an error of about 10 μm to 15 μm occurs when the film thickness is about 100 μm, and an error of about 20 μm to 30 μm occurs when the film thickness is about 200 μm. For this reason, when the organic layer 12 and the upper electrode 13 are vapor-deposited using a film mask, the problem that a fine pattern cannot be formed correctly arises.
[0011]
For this reason, it is also conceivable to perform vapor deposition by using a member other than the film mask, for example, a thin line as a shadow mask. However, when a thin line or the like is used, only a linear pattern can be formed, and the degree of freedom of pattern formation is significantly hindered.
[0012]
As shown in FIGS. 5A and 5B, when the transparent electrode 17 is formed by etching using the photoresist 21 as a mask, the crystal is exposed on the surface of the side surface 18 and fine irregularities are generated. And it is necessary to perform a grinding | polishing operation | work in order to remove this unevenness | corrugation, a process increases and working efficiency falls.
[0013]
Furthermore, since the side surface 18 is formed as a steep slope, as shown in FIG. 6B, the film thickness L3 of the organic layer 12 formed on the upper side of the side surface 18 is the film thickness L1 of the organic layer 12 in the flat portion. There is a problem that the thickness of the upper layer of the transparent electrode 17 becomes non-uniform. Since the current density in the organic EL element is almost inversely proportional to the cube of the thickness of the organic layer 12, the current concentrates on the thin L3 portion, and only this portion emits light strongly, causing uneven light emission and shortening the product life. Will be invited.
[0014]
Accordingly, the present invention provides a pattern forming element manufacturing apparatus and method that can form a fine pattern on a substrate with a high degree of freedom and that can substantially uniform the thickness of the upper layer of the slope. Objective.
[0015]
[Means for Solving the Problems and Effects of the Invention]
In the method for manufacturing an EL display panel according to the present invention , a mask is formed by a combination of a planar mask having an opening and a linear mask.
[0016]
By using the planar mask, the degree of freedom of the pattern shape to be formed can be increased by selecting the shape of the opening, and by using the linear mask, a fine pattern shape can be obtained. Therefore, by forming a mask by combining a planar mask and a linear mask, a fine pattern with a high degree of freedom can be formed on the substrate.
[0017]
In the method for manufacturing an EL display panel according to the present invention , the cross-sectional shape of the linear mask is circular. Therefore, the end portion of the pattern formed in the linear mask portion is formed as a gentle slope along the circular shape of the linear mask. For this reason, when the upper layer is formed over the slope of the pattern, the film thickness of the upper layer can be made substantially uniform, and inconvenience due to variations in the film thickness of the upper layer can be avoided.
[0018]
In the method for manufacturing an EL display panel according to the present invention , a glass substrate is placed on top of the linear mask, the glass substrate is held, and the linear mask has a tension that is in close contact with the placed glass substrate. It is arranged with. For this reason, the substrate and the linear mask can be reliably brought into close contact by the weight of the substrate and the tension of the linear mask, and an accurate pattern can be formed on the substrate.
[0019]
In the method for manufacturing an EL display panel according to the present invention , a weight is placed on the glass substrate. Due to the weight of the weight, the adhesion between the substrate and the linear mask is increased, and a more accurate pattern can be formed on the substrate.
[0020]
In the EL display panel manufacturing method according to the present invention , a magnet is placed on the glass substrate, and the linear mask is magnetized according to the magnetic field formed by the magnet. For this reason, a linear mask is attracted | sucked toward a magnet, the adhesiveness of a board | substrate and a linear mask improves, and a more exact pattern can be formed in a board | substrate.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a pattern forming element manufacturing apparatus and method according to the present invention will be described taking the manufacture of an EL display panel 25 of an EL display as an example. In this embodiment, the EL display panel 25 is a pattern forming element. FIG. 1 is a perspective view showing a glass substrate 2, a thin wire 3, and a film mask 4 for manufacturing an EL display panel 25 in the present embodiment. 2A is an enlarged sectional view in the vicinity of the glass substrate 2 and the thin wire 3 shown in FIG. 1, and FIG. 2B is a partially enlarged sectional view of the EL display 25.
[0022]
Further, FIG. 3A is a side view showing an embodiment for closely attaching the thin wire 3 to the glass substrate 2, and FIG. 3B is a side view showing another embodiment for closely attaching the thin wire 3 to the glass substrate 2. FIG. 3C is a side view showing still another embodiment for bringing the thin wire 3 into close contact with the glass substrate 2. FIG. 4 is a perspective view showing an EL display panel 25 using organic EL elements.
[0023]
As shown in FIG. 4, in the EL display panel 25, a plurality of strip-shaped transparent electrodes 11 are arranged on the glass substrate 2 along the arrow 93 direction. A plurality of strip-shaped organic layers 12 are disposed on the transparent electrode 11 along a direction of an arrow 94 perpendicular to the direction of the arrow 93 on the plane to which the direction of the arrow 93 belongs. Further, a plurality of strip-shaped upper electrodes 13 are disposed on each organic layer 12 so as to overlap each other.
[0024]
The width of each transparent electrode 11, the organic layer 12, and the upper electrode 13 is about 300 μm, and each strip-shaped gap is as fine as about 30 μm to 50 μm. 1 and 4 are diagrams for schematically showing the transparent electrode 11, the organic layer 12, and the upper electrode 13 arranged on the glass substrate 2, and actually the fine transparent electrode 11 and the organic layer are shown. 12. Many upper electrodes 13 are arranged on the glass substrate 2.
[0025]
If a predetermined transparent electrode 11 and a predetermined upper electrode 13 are selected and a voltage is applied to the EL display panel 25, the organic layer 12 positioned at the intersection of the selected transparent electrode 11 and the upper electrode 13. Emits light. Therefore, by controlling the selection of the transparent electrode 11 and the upper electrode 13, a desired display can be performed using the EL display panel 25.
[0026]
In the present embodiment, the transparent electrode 11, the organic layer 12, and the upper electrode 13 shown in FIG. 4 are formed on the glass substrate 2 as a substrate by a vapor deposition technique using a shadow mask. In addition, since the vapor deposition technique is a generally known technique, the detailed content of vapor deposition is abbreviate | omitted.
[0027]
As described above, since the shadow mask is used and the photoresist is not used as a mask, by using the shadow mask several times, the organic layer 12 arranged in the direction of the arrow 94 is sequentially different in the lateral direction. (Elements having different emission colors) can be formed, and for example, a color display can be easily manufactured.
[0028]
As shown in FIG. 1, in this embodiment, a shadow mask 5 as a mask is configured by a combination of a film mask 4 as a planar mask and a thin line 3 as a linear mask. A mask opening 4S as an opening is formed in the film mask 4 by etching. In the present embodiment, a square mask opening 4S is formed.
[0029]
As the thin wire 3, a SUS440 piano wire or tegus is used. The fine wire 3 is in contact with the glass substrate 2 and is in close contact therewith. Further, the film mask 4 is brought into contact with or held close to the fine wire 3 in a state where the film mask 4 is brought closer to the arrow 90 direction from the state shown in FIG.
[0030]
FIG. 3A shows a specific positional relationship between the glass substrate 2, the thin wire 3, and the film mask 4. As shown in FIG. 3A, a glass substrate 2 is placed on top of the thin wire 3 to hold the glass substrate 2. Then, both ends of each fine wire 3 are fixed by a fine wire holder 6.
[0031]
The thin wire 3 is stretched between the thin wire holders 6 with a predetermined tension. When the glass substrate 2 is placed on the thin wire 3, the thin wire 3 is attached to the glass substrate 2 by the weight of the glass substrate 2 and the tension of the thin wire 3. Is in close contact. A film mask 4 is disposed in the vicinity of the thin line 3. The end of the film mask 4 is supported by a shadow mask holder 7.
[0032]
In this state, evaporation atoms 20 as particles are given from the evaporation source 10 toward the glass substrate 2 (resistance heating vacuum deposition), and the transparent electrode 11 is first formed on the glass substrate 2. When vapor deposition is performed, in order to average the evaporated atoms 20 with respect to the glass substrate 2, the evaporated atoms 20 are given if the glass substrate 2 is rotated. In this case, the rotation center of the glass substrate 2 and the evaporation source 10 are arranged in a shifted positional relationship.
[0033]
A part of the evaporated atoms 20 is blocked by the shadow mask 5 constituted by the thin line 3 and the film mask 4, and is a mask opening 4S portion of the film mask 4 and a portion corresponding to the gap portion between the thin lines 3. The evaporated atoms 20 adhere and a pattern is formed.
[0034]
That is, by using the thin wire 3 as a mask, each strip-shaped transparent electrode 11 having a gap S1 can be formed. As described above, since the fine wire 3 is in close contact with the glass substrate 2 due to the tension of the fine wire 3 and the own weight of the glass substrate 2, it is possible to prevent the evaporation atoms 20 from entering the floating portion between the fine wire 3 and the glass substrate 2. And an accurate pattern can be obtained. In addition, it becomes possible to obtain the transparent electrode 11 of a fine pattern by using the thin wire | line 3 with a cross-sectional diameter of about 30 micrometers-50 micrometers.
[0035]
Further, by using the film mask 4 as a mask, it is possible to obtain the peripheral regions S3 and S4 where the transparent electrode 11 is not formed. Since the mask opening 4S of the film mask 4 is formed by etching, the shape of the mask opening 4S can be freely set, and the degree of freedom of the pattern shape can be increased. When the mask opening 4S is formed by etching, the error becomes relatively large. However, since the high-precision dimensions are not required for the peripheral regions S3 and S4, there is practically no inconvenience.
[0036]
As the thin wire 3 in the present embodiment, one having a circular cross section as shown in FIG. 2A is used. For this reason, the side surface 14 (end part) of the transparent electrode 11 is formed as a gentle slope along the circular shape of the thin wire 3. FIG. 2A is a schematic diagram for showing the positional relationship between the transparent electrode 11 and the thin wire 3, and the relationship between the dimensions of the transparent electrode 11 and the thin wire 3 is different from the actual one.
[0037]
After forming the transparent electrode 11 on the glass substrate 2 as described above, the organic layer 12 and the upper electrode 13 are sequentially formed by vapor deposition using the shadow mask 5 composed of the thin wire 3 and the film mask 4 in the same manner as described above. ,Form. FIG. 2B shows the laminated transparent electrode 11, organic layer 12, and upper electrode 13.
[0038]
As described above, since the side surface 14 of the transparent electrode 11 is formed as a gentle slope along the circle of the thin wire 3, the film thickness L2 of the organic layer 12 formed on the side surface 14 is a flat organic layer. 12 film thickness L1. For this reason, the nonuniformity of the film thickness of the upper layer (organic layer 12) of the transparent electrode 11 can be avoided. Thereby, uniform light emission and prevention of shortening of the product life can be realized.
[0039]
In addition, since the transparent electrode 11 is not formed by etching, the crystal is not exposed on the side surface 14 of the transparent electrode 11, and it is not necessary to perform a polishing operation to remove the unevenness due to the crystal. For this reason, working efficiency can be improved.
[0040]
In the above embodiment, as shown in FIG. 3A, the thin wire 3 is brought into close contact with the glass substrate 2 by the tension of the thin wire 3 and the weight of the glass substrate 2. However, the configuration shown in FIG. 3B can be used as another embodiment. In the configuration of FIG. 3B, a plurality of weights 8 are further placed on the glass substrate 2 in addition to the state of FIG. 3A.
[0041]
When the weight 8 increases in weight, the adhesion between the glass substrate 2 and the thin wire 3 is improved, and a more accurate pattern can be formed on the glass substrate 2. In the example of FIG. 3B, a plurality of weights 8 are placed, but a single weight 8 may be placed.
[0042]
Furthermore, the configuration shown in FIG. 3C can be used as still another embodiment. In the configuration of FIG. 3C, a magnet 9 is further placed on the glass substrate 2 in addition to the state of FIG. 3A. In this embodiment, a piano wire or the like that is magnetized according to the magnetic field formed by the magnet 9 is used as the thin wire 3.
[0043]
For this reason, the fine wire 3 is attracted toward the magnet 9, the adhesion between the glass substrate 2 and the fine wire 3 is increased, and a more accurate pattern can be formed on the glass substrate 2. In the example of FIG. 3C, a plurality of magnets 9 are mounted, but a single magnet 9 may be mounted.
[0044]
The pattern forming element manufacturing apparatus and method are not limited to those exemplified in the above embodiment. In the above embodiment, the thin line 3 as the linear mask and the film mask 4 as the planar mask are supported by the thin line holder 6 and the shadow mask holder 7 as separate members. It is also possible to form the mask by fixing both ends of the mask and using both as an integral member. By fixing both ends of the linear mask to the planar mask, the opening of the planar mask is not restricted by the linear mask, and the degree of freedom of pattern formation is further increased.
[0045]
Moreover, in the said embodiment, although the square mask opening part 4S is formed in the film mask 4, it is possible to select the shape of the opening part formed in a planar mask freely according to a desired pattern. it can. Furthermore, the cross-sectional shape of the thin wire 3 may be a shape other than a circle. Further, the weight 8 shown in FIG. 3B and the magnet 9 shown in FIG. 3C may be mixed and placed on the glass substrate 2.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a glass substrate 2, thin wires 3, and a film mask 4 for manufacturing an EL display which is an embodiment of a pattern forming element manufacturing apparatus and method according to the present invention.
2A is an enlarged cross-sectional view of the vicinity of the glass substrate 2 and the thin wire 3 shown in FIG. 1, and B is a partial enlarged cross-sectional view of an EL display 25. FIG.
FIG. 3A is a side view showing an embodiment for bringing the thin wire 3 into close contact with the glass substrate 2, and B is a side view showing another embodiment for bringing the thin wire 3 into close contact with the glass substrate 2. , C is a side view showing still another embodiment for bringing the thin wire 3 into close contact with the glass substrate 2.
FIG. 4 is a perspective view showing an EL display panel 25 using organic EL elements.
FIG. 5 is a diagram showing a process of forming a transparent electrode 17 on a glass substrate 2 in a conventional EL display.
[Explanation of symbols]
2. Glass substrate 3 Fine wire 4 Film mask 4S Mask opening 5 Shadow mask 8 Weight 9 ... Magnet 20 ... Evaporation atom

Claims (5)

A plurality of strip-shaped transparent electrodes arranged along the first direction on the glass substrate, an organic layer arranged along the second direction orthogonal to the first direction on the transparent electrode, An upper electrode disposed so as to overlap the organic layer,
An EL display panel using an organic EL element that emits light from an organic layer located at an intersection of a selected transparent electrode and an upper electrode,
Sectional shape formed on the side surface of the transparent electrode by vapor deposition using a circular line-shaped mask as gentle slope, the film thickness of the organic layer formed on the side surface and the thickness of the organic layer of the flat portion substantially the same Configured to be
An EL display panel characterized by that. A plurality of strip-shaped transparent electrodes are arranged on the glass substrate along the first direction,
An organic layer is disposed on the transparent electrode along a second direction orthogonal to the first direction,
Overlaid on the organic layer and formed by arranging the upper electrode,
A method of manufacturing an EL display panel using an organic EL element that emits light from an organic layer located at an intersection between a selected transparent electrode and an upper electrode,
An organic layer formed on the side surface by forming the side surface of the transparent electrode as a gentle slope by vapor deposition using a mask composed of a linear mask having a circular cross-sectional shape and a planar mask in which openings are formed. and configured to be substantially the same thickness of the layer and the thickness of the organic layer of the flat portion,
An EL display panel manufacturing method characterized by the above. In the manufacturing method of the EL display panel according to claim 2,
A glass substrate is placed on top of the linear mask, the glass substrate is held,
The linear mask is arranged with a tension of close contact with the placed glass substrate.
An EL display panel manufacturing method characterized by the above. In the manufacturing method of the EL display panel according to claim 3,
A weight is placed on top of the glass substrate.
An EL display panel manufacturing method characterized by the above. In the manufacturing method of the EL display panel according to claim 3,
A magnet is placed on the top of the glass substrate,
The linear mask is magnetized according to the magnetic field formed by the magnet,
An EL display panel manufacturing method characterized by the above.

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