The present application claims priority from Japanese Application JP 2008-309527 filed on Dec. 4, 2008, the content of which is hereby incorporated by reference into this application.
1. Field of the Invention
The present invention relates to a manufacturing method of a display device, a manufacturing apparatus of a display device, and a display device, and more particularly to a manufacturing method of a display device having a display region in which a plurality of light emitting elements are formed, a manufacturing apparatus of a display device, and a display device.
2. Background Art
Recently, there has been proposed a display device which displays various kinds of information by integrating a large number of light emitting elements on a substrate. As a typical example of such a display device, an organic electroluminescence display (OLED) which makes use of emission of light by electroluminescence can be named. Conventionally, with respect to such an organic electroluminescence display, to protect elements formed on a substrate, in forming a display panel, a sealing material is applied to the substrate such that the sealing material surrounds a periphery of a display part, and sealing glass is adhered to the substrate. A space is defined between the substrate and the sealing glass, and an inert gas and a desiccant are sealed in the space.
The above-mentioned sealing method is referred to as hollow sealing. Such a sealing method, however, has drawbacks including following drawbacks. That is, it is necessary to perform working for forming recessed portions in the sealing glass. Coating of the sealing material requires time. When the sealing glass is deflected and comes into contact with an element on the substrate, there arises a possibility that the element is broken. Accordingly, it is preferable to adopt total sealing which is a sealing method where all elements on a substrate are covered with a resin, and sealing glass is adhered to the resin from above.
However, the total sealing produces a panel having the structure where a hardened resin layer is sandwiched between the substrate and the sealing glass and hence, cutting of the panel becomes difficult. Currently, a scribe-break method has been popularly used as a method for cutting a panel. However, in applying such a method to the panel having the resin layer, a crack which is formed in glass in a scribing step stops at the resin layer so that the hardened resin layer cannot be cut. Accordingly, the use of the scribe-break method gives rise to not only a possibility that a sharp cutting surface cannot be obtained but also a possibility that the panel per se is broken.
On the other hand, to increase production efficiency of display devices, it is necessary to use a so-called multiple-piece simultaneous manufacturing method where a panel is prepared by forming a large number of display devices on a large substrate, and the respective display devices are obtained by cutting the panel. Accordingly, it is necessary to apply a technique which ensures favorable cutting of a panel and enables multiple-piece simultaneous manufacturing even to the display device which adopts the total sealing.
In this respect, JP-A-2005-322633 (patent document 1) describes a method where a large number of display parts are formed on a substrate, a sealing material is applied to the substrate such that the sealing material surrounds the peripheries of the respective display parts, a resin is filled in the inside of the respective display parts surrounded by the sealing material, and sealing glass is adhered to the substrate (see
According to the method disclosed in patent document 1, a portion which is not filled with the resin is formed between the display parts and hence, it is considered that no particular problem arises in cutting a panel. However, such a method requires a complicated and time-consuming step where the sealing material is applied to the substrate such that the sealing material surrounds the peripheries of the plurality of display parts individually, and the resin is filled in the inside of the respective display parts surrounded by the sealing material. Accordingly, it is impossible to sufficiently enhance the production efficiency of the display device.
The present invention has been made in view of such drawbacks, and it is an object of the present invention to provide a manufacturing method and a manufacturing apparatus of a display device which can favorably cut a display panel having the structure where a resin layer is sandwiched between the element substrate and the sealing substrate, and a display device manufactured by such a method.
To briefly explain the summary of typical inventions among inventions described in this specification, they are as follows.
(1) According to one aspect of the present invention, there is provided a manufacturing method of a display device which includes the steps of: forming a display panel by sandwiching a resin which is hardened by any one of electromagnetic waves, radioactive rays and electron beams and heat between an element substrate having a display region in which a plurality of light emitting elements are formed and a sealing substrate in such a manner that the resin covers the display region; radiating at least one of electromagnetic waves, radioactive rays and electron beams to the display panel thus hardening first portions of the resin and leaving second portions of the resin in a state softer than the first portions; separating the display panel at positions corresponding to the second portions; and heating the separated display panel thus further hardening the resin.
(2) In the manufacturing method of a display device having the constitution (1), the element substrate has a plurality of display regions, and the second portions include portions each of which is sandwiched between every two display regions out of the plurality of display regions.
(3) In the manufacturing method of a display device having the constitution (1), the resin covers the display regions and the second portions include the display regions.
(4) In the manufacturing method of a display device having the constitution (1), at least one of electromagnetic waves, radioactive rays and electron beams is blocked partially in the radiation step thus leaving the second portions.
(5) In the manufacturing method of a display device having the constitution (1), in the separation step, the display panel is separated by applying scribing to at least one of the element substrate and the sealing substrate and, thereafter, by breaking the display panel.
(6) According to another aspect of the present invention, there is provided a manufacturing apparatus of a display device which includes: a panel forming device which forms a display panel by sandwiching a resin which is hardened by any one of electromagnetic waves, radioactive rays and electron beams and heat between an element substrate having a display region in which a plurality of light emitting elements are formed and a sealing substrate in such a manner that the resin covers the display region; a radiation device which radiates at least one of electromagnetic waves, radioactive rays and electron beams to the display panel thus hardening first portions of the resin and leaving second portions of the resin in a state softer than the first portions; a separation device which separates the display panel at positions corresponding to the second portions; and a heating device which heats the separated display panel thus further hardening the resin.
(7) In the manufacturing apparatus of a display device having the constitution (6), the radiation device partially blocks at least one of electromagnetic waves, radioactive rays and electron beams.
(8) In the manufacturing apparatus of a display device having the constitution (6), the separation device separates the display panel by applying scribing to at least either one of the element substrate and the sealing substrate and, thereafter, by breaking the display panel.
(9) According to still another aspect of the present invention, there is provided a display device which includes: an element substrate which includes a display region in which a plurality of light emitting elements are formed; a sealing substrate; and a resin layer which is sandwiched between the element substrate and the sealing substrate and covers the display region, wherein on at least one side of the display device, a region at an edge portion of the resin layer exhibits a higher thermal hardening rate and a lower radiation hardening rate attributed to at least one of electromagnetic waves, radioactive rays and electron beams compared to a region inside the region at the edge portion of the resin layer.
(10) In the display device having the constitution (9), a region of the resin layer which corresponds to the display region exhibits a higher thermal hardening rate compared to the region inside the region at the edge portion of the resin layer.
According to the above-mentioned inventions, it is possible to provide the manufacturing method of a display device, the manufacturing apparatus of a display device which can favorably cut the display panel having the structure where the resin layer is sandwiched between the element substrate and the sealing substrate, and the display device manufactured by the manufacturing method.
Hereinafter, a first preferred embodiment of the present invention is explained in conjunction with drawings.
The element substrate receiving portion 2 is a buffer which receives and stocks an element substrate 20 on which a plurality of light emitting elements are formed, and the sealing substrate receiving portion 3 is a buffer which receives and stocks a sealing substrate 30. The element substrate 20 and the sealing substrate 30 are conveyed from a preceding step using an arbitrary conveying means such as a conveying robot or a conveyer. The adhesion device 4 is a device which forms a display panel by adhering the element substrate 20 and the sealing substrate 30 to each other with a resin sandwiched therebetween. The radiation device 5 is a device which radiates at least one of electromagnetic waves, radioactive rays and electron beams to the display panel thus temporarily hardening the resin. Here, temporary hardening implies hardening to an extent that the resin is not completely hardened. The separation device 6 is a device which cuts and separates the display panel by a scribe-break method.
The conveyance of the element substrate 20, the sealing substrate 30 and the display panel among the element substrate receiving portion 2, the sealing substrate receiving portion 3, the adhesion device 4, the radiation device 5 and the separation device 6 is performed by the receiving-side conveying device 9. In the drawing, the receiving-side conveying device 9 is illustrated as a scalar-type robot provided with a suction hand. However, the receiving-side conveying device 9 is not limited to such a robot, and any device can be used provided that the device can convey the element substrate 20, the sealing substrate 30 and the display panel.
The heating device 7 is a device which hardens the resin by heating the separated display panel. As the heating device 7, various kinds of heating devices such as a hot plate, a hot-air heating device or an infrared heating device can be used. The delivery portion 8 is a buffer which stocks an obtained display device 101 and, at the same time, delivers the display device 101 to a succeeding step using an arbitrary conveyance means such as a conveying robot or a conveyer.
In this embodiment, the manufacturing apparatus 1 is described as a so-called station-type manufacturing apparatus which includes the element substrate receiving portion 2, the sealing substrate receiving portion 3 and the delivery portion 8 and, at the same time, performs the conveyance of the display panel among the respective devices using the robots. However, the manufacturing apparatus 1 is not limited to such a station-type manufacturing apparatus, and may be a so-called line-type manufacturing apparatus where a product flows toward a down stream side from an upper stream side. Further, with respect to the respective devices, one set of device is provided for each device in the drawing. However, the number of devices for the same device is not limited, and a plurality of devices may be provided for the same device. Further, devices not shown in the drawing may be provided additionally. As one example, a polishing device which polishes an edge surface of the display device 101, a cleaning device or the like may be added.
Next, a manufacturing method of the display device 101 using the manufacturing apparatus 1 is explained in conjunction with
A first step is a panel forming step indicated by (1a) and (1b) in
In
At this point of time, the resin 40 is not hardened so that the resin 40 is soft. Accordingly, when the resin 40 is sandwiched between the element substrate 20 and the sealing substrate 30, as indicated by (1b) in
The next step is a radiation step indicated by (2) shown in
Here, although the degree of temporary hardening depends on property of the resin 40, assume a radiation quantity of ultraviolet rays for completely hardening the resin 40 as 100, it is preferable to set the radiation quantity of ultraviolet rays to approximately 10 to 50, and it is more preferable to set the radiation quantity of ultraviolet rays to approximately 20 to 40. Further, in this embodiment, the ultraviolet rays are not radiated to the second portions 42 so that the second portions are not hardened. However, it is not always necessary to prevent the second portions 42 from being completely hardened. As described later, provided that the second portions 42 are soft to an extent that the display panel 100 can be separated, the second portions 42 may be hardened by radiating ultraviolet rays to the second portions 42. In any case, the second portion 42 remain in a soft state compared to the first portions 41 which fix the positional relationship between the element substrate 20 and the sealing substrate 30.
Further, in this embodiment, the radiation device 5 uses the mask 50 for blocking ultraviolet rays. However, ultraviolet rays may be radiated to only necessary portions of the resin 40 without using the mask 50.
After the radiation step is finished, the display panel 100 is conveyed to the separation device 6 using the receiving-side conveying device 9.
The next step is a separation step indicated by (3a) and (3b) in
Firstly, as schematically indicated by (3a) in
Subsequently, an external force such as vibrations or bending is applied to the display panel 100 thus cutting the display panel 100 at positions where scribing is made as schematically indicated by (3b) in
The final step is a heating step indicated by (4) in
As described previously, provided that no problem arises in the separation step, there arises no problem in slightly hardening the second portion 42 by also applying ultraviolet rays to the second portion 42. Eventually, the region 44 at the edge portion exhibits a higher thermal hardening rate and a lower ultraviolet-ray hardening rate compared to the inner region 43. The same goes for a case where electromagnetic waves, radioactive rays or electron beams except for that ultraviolet rays are used in the radiation step.
When the hardening of the resin 40 is finished in this manner, each display device 101 is conveyed to the delivery part 8 by the delivery-side conveying device 10. Each display device 101 is, thereafter, conveyed to a downstream step by a conveying device such as a conveyer not shown in the drawing, electronic circuits such as drivers and a frame are mounted on the display device 101, and the display device 101 is shipped as a product by way of inspection and the like.
Here, in the above-mentioned embodiment, the explanation has been made with respect to the case where the organic electroluminescence display device is used as the display device 101. The organic electroluminescence display device is roughly classified into two types of display devices consisting of a top-emission-type display device which takes out emitted light from a sealing substrate side and a bottom-emission-type display device which takes out emitted light from an element substrate side. This embodiment is applicable to both the top-emission-type display device and the bottom-emission-type display device. In the top-emission-type display device, it is necessary to form at least the sealing substrate 30 and the resin 40 using a transparent material. On the other hand, in the top-emission-type display device, the element substrate 20 is transparent.
In this embodiment, in the radiation step indicated by (2) in
Thereafter, in a display device 101 which is obtained through a separation step and a heating step which follow the above-mentioned radiation step, as shown in the drawing, on at least one side of the display region 21, a region 44 which constitutes an edge portion of a layer made of the resin 40 is hardened only by heating, and a region 43 which is arranged inside the region 44 is hardened also by the radiation of ultraviolet rays, and a region 45 which is arranged inside the region 43 and corresponds to the display region 21 are hardened only by heating.
It is needless to say that also in this embodiment, in the same manner as the first embodiment, provided that no problem arises in the separation step, the second portion 42 may be slightly hardened by also applying ultraviolet rays to the second portion 42. Accordingly, the region 44 at the edge portion and the region 45 corresponding to the display region 21 exhibit a higher thermal hardening rate and a lower ultraviolet-ray hardening rate compared to the inner region 43. Further, in the same manner as the first embodiment, electromagnetic waves, radioactive rays or electron beams other than ultraviolet rays may be used in the radiation step.
Number | Date | Country | Kind |
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2008-309527 | Dec 2008 | JP | national |