JP4323115B2 - Method for manufacturing functional panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a functional panel including a functional element substrate in which a functional element such as a thin film transistor (TFT) is attached to a flexible sheet.
[0002]
[Prior art]
When a liquid crystal display or the like is manufactured using a TFT (Thin Film Transistor) as a functional element, the TFT is formed on a transparent substrate such as glass by a CVD (Chemical Vapor Deposition) method or the like. Since the process of forming the TFT on the substrate involves high-temperature treatment, it is necessary to use a material having a high softening point and melting point and excellent heat resistance for the substrate. Therefore, at present, heat-resistant glass having heat resistance of around 500 ° C. is used as the substrate.
[0003]
The substrate on which the functional element is formed needs to satisfy the conditions for manufacturing the functional element substrate. However, the substrate on which the functional element is formed may not have effective characteristics in actual use after being commercialized.
[0004]
For example, a glass substrate is a substrate suitable for manufacturing a liquid crystal display using a TFT, which is a functional element. On the other hand, a glass substrate is heavy, easily broken, and weak in deformation. Liquid crystal displays used in portable electronic device products such as mobile phones and portable terminals, for which demand is rapidly increasing, require a substrate that is inexpensive and light, withstands deformation, and does not break even when dropped. However, such a substrate does not have the heat resistance necessary for the manufacturing process, and there is a problem that the substrate is warped when the substrate is conveyed. That is, there is a gap between the characteristics required of the substrate from the manufacturing conditions and the characteristics required of the substrate after commercialization, and it is extremely difficult to select a substrate that satisfies both characteristics at the same time.
[0005]
In the method for transferring a thin film element disclosed in JP-A-10-125931, a separation layer is formed between the thin film element, which is a functional element, and a substrate used in manufacturing, and laser light is irradiated from the substrate side. After separating the thin film element from the substrate used at the time of manufacture by causing separation at the separation layer, the thin film element is transferred to the substrate used at the product, thereby separating the substrate used at the time of manufacture from the substrate used at the product. ing.
[0006]
In the method of manufacturing a liquid crystal display element disclosed in Japanese Patent Application Laid-Open No. 7-209633, the first half process in which the plastic substrate is processed at a temperature lower than the temperature at which the plastic substrate undergoes thermal deformation is caused to flow by a roll-to-roll method. By flowing according to the formula, a liquid crystal display element using a plastic substrate can be manufactured with high productivity, and its durability and reliability can be improved.
[0007]
[Problems to be solved by the invention]
In the thin film element transfer method disclosed in Japanese Patent Application Laid-Open No. 10-125931, heat is generated and the thin film element is heated when the separation layer absorbs the laser beam to separate the thin film element and the substrate. There is a problem that the performance of the thin film element is lowered.
[0008]
Japanese Patent Laid-Open No. 7-209633 discloses a method for manufacturing a liquid crystal display element using a plastic substrate with high productivity. This method of manufacturing a liquid crystal display element is effective when manufacturing a panel having no functional element. However, when manufacturing a panel having a functional element, the liquid crystal display element involves high-temperature treatment in the first step of forming the functional element. The manufacturing method of the display element is not suitable.
[0009]
Moreover, in order to enlarge the display area, the current liquid crystal display is used by packaging two panels side by side and connecting them with a hinge or the like. Such a liquid crystal display has a problem that a non-displayable area exists between two panels, and it is difficult to display a continuous video or characters. In the future, liquid crystal displays of portable electronic device products need to display image information using a large screen or a plurality of screens in order to expand the display area. Further, the liquid crystal display of the portable electronic device product needs to be stored so that it can be easily carried when not in use.
[0010]
An object of the present invention is to provide a functional panel having both reliability and portability, and a functional panel manufacturing method for manufacturing the functional panel with high productivity.
[0011]
Another object of the present invention is to provide a functional panel manufacturing method for efficiently manufacturing a functional panel having a plurality of panels.
[0012]
[Means for Solving the Problems]
The present invention reduces the thickness of the substrate by reducing the thickness from the back surface of the glass substrate having functional elements formed on the surface, and the thinned substrate is flexible and thinned. Paste a reinforcing layer to reinforce the
The reinforcing layer is a belt-like sheet, and further performs at least one of washing, substrate mounting, and cutting while the substrate is attached, while continuously feeding the sheet,
And for substrate protection or panel terminal protection, a protective film of varying adhesive force by ultraviolet irradiation, a method of manufacturing a functional panel wherein the paste it while feeding the sheet.
[0013]
When the substrate is a glass substrate, it has heat resistance and is suitable for forming a functional element, but is heavy. Therefore, when the substrate is made thinner and lighter, there is a problem that it is easily broken. Therefore, in the present invention, for example, a sheet is attached to a thinned substrate, or a polymer solvent is applied and cured to form a flexible reinforcing layer. In this way, a functional panel including a functional element substrate that is highly reliable, lightweight, and portable can be manufactured.
Since the substrate is made of glass having heat resistance, corrosion resistance, and the like, a functional element having good performance can be formed on the substrate.
[0014]
This reinforcing layer does not have to be suitable for forming a functional element, and can be selected according to the properties required for the product. Therefore, a functional panel including a functional element substrate having properties required for a product can be manufactured by using a conventional manufacturing process as it is. Moreover, since each process is performed continuously while feeding the sheet on which the panel is pasted, productivity can be improved.
In addition, a protective film whose adhesive strength changes when irradiated with ultraviolet rays is used to protect the substrate or panel terminals, so that when the protective film is peeled off from a thin panel, the panel is protected without imposing a burden on the panel. The film can be peeled off.
[0015]
In addition, the present invention is characterized in that a barrier layer that protects the functional element when the substrate is thinned is formed between the functional element and the substrate.
[0016]
According to the present invention, since the barrier layer is formed between the functional element and the substrate, the barrier layer serves as a stopper when the substrate is thinned, and the substrate can be uniformly thinned.
[0017]
Further, according to the present invention, it is possible to easily manage the conditions when the substrate is thinned.
[0018]
In the invention, it is preferable that the barrier layer is made of a metal oxide.
According to the present invention, since the barrier layer is made of a metal oxide that is harder than chemicals and has chemical resistance, the functional element can be protected when the substrate is thinned.
[0020]
In the invention, it is preferable that the reinforcing layer is made of an organic polymer.
According to the present invention, since the transfer body is made of an organic polymer, a functional element substrate having excellent impact resistance and a light weight can be manufactured.
[0031]
Further, the present invention is characterized in that a functional panel in which a plurality of panels are connected and integrated is manufactured by dividing the sheet while leaving two or more adjacent panels attached to the sheet. .
[0032]
According to the present invention, since two or more panels are integrated, a functional panel in a state where each panel is connected can be manufactured.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a process diagram in the case of manufacturing a liquid crystal panel 34 using a method for manufacturing a functional panel according to an embodiment of the present invention. Hereinafter, a method for manufacturing the liquid crystal panel 34 will be described with reference to FIG.
[0036]
(1) First, a tantalum thin film is formed on a glass substrate 1 by sputtering. This tantalum is anodized to form tantalum oxide to form the barrier layer 2. On the barrier layer 2, the functional element layer 3 in which the TFT is formed is formed by sequentially performing gate electrode wiring, gate insulating layer formation, amorphous silicon semiconductor layer formation, source electrode wiring, and the like. In this way, the functional element substrate 10 is obtained. Similarly, the barrier layer 12 is formed on the glass substrate 11, and the color filter layer 13 is formed on the barrier layer 12. In this way, the color filter substrate 20 is obtained.
[0037]
(2) Plastic beads are dispersed between the functional element substrate 10 and the color filter substrate 20 to bond the functional element substrate 10 and the color filter substrate 20 together. At this time, the functional element layer 3 and the color filter layer 13 are arranged inside. The reason why the plastic beads are dispersed between the functional element substrate 10 and the color filter substrate 20 is to make the substrate interval uniform 5 μm. After the functional element substrate 10 and the color filter substrate 20 are bonded together, liquid crystal is injected between the substrates, and the injection port is sealed to form the liquid crystal layer 25. In this way, the panel 30 is obtained.
[0038]
(3) Next, in order to prevent the substrate 1 and the substrate 11 of the panel 30 from being thinned at the same time, a UV (ultraviolet) sheet 26 having acid resistance is attached as a protective film on the substrate 11 of the panel 30. The UV sheet 26 is a sheet using an acrylic adhesive whose adhesive strength decreases when irradiated with ultraviolet rays. The UV sheet 26 can be peeled off without placing a burden on the thinned panel by etching. Further, protection is performed in order to prevent the etchant from permeating from the periphery of the panel 30 or to prevent the connection terminals of the panel 30 from being eroded. A UV sheet 29 similar to the UV sheet 26 is attached to the flat portion of the connection terminal. A resin 28 that can withstand acrylic or fluorine etching is applied and cured on the stepped portion and the periphery. If the thickness of the UV sheet 26 is about 200 μm, it is possible to cover even uneven portions, so that the connection terminal portion of the panel 30 can also be protected by the UV sheet 26.
[0039]
(4) The panel 31 prepared in this way is etched using an etchant composed of an aqueous solution of hydrofluoric acid. The tantalum oxide that is the barrier layer 2 is not dissolved in the etching solution. Accordingly, the layer composed of the barrier layer 2, the functional element layer 3, the liquid crystal layer 25, the color filter layer 13, the barrier layer 12, the substrate 11, the UV sheet 26, and the thinned substrate 1a remains. That is, the thinned panel 32 remains. The substrate 1 may be partially removed completely. Next, the UV sheet 26 and the UV sheet 29 are peeled off from the thinned panel 32, rinsed with pure water, and dried.
[0040]
Then, a panel is affixed on the strip | belt-shaped base sheet 6 which has flexibility, and the liquid crystal panel 34 is manufactured by a roll-to-roll system.
[0041]
FIG. 2 is a schematic view showing a roll-to-roll process in the manufacturing process of the liquid crystal panel 34. Since FIG. 2 is a schematic diagram, the size of each base sheet driving roller 57 is small, but the actual base sheet driving roller 57 needs to have a shape that does not place a burden on the panel. For example, the base sheet driving roller 57 itself is made flexible so that it can be adapted even if the panel contacts. Alternatively, the base sheet 6 is not bent at a right angle but is gently bent at the place where the base sheet 6 is bent. For example, the base sheet 6 is bent at an angle of 45 degrees or less.
[0042]
(5) The panel in which the thinning of the substrate 1 is completed is attached to the base sheet 6 by the adhesive layer 5 made of resin. At this time, the thinned substrate 1 a side is attached to the base sheet 6. The base sheet 6 is not only used for conveyance but is finally made a part of the product. For this purpose, as shown in FIG. 2, the alignment mark on the panel and the alignment mark on the base sheet 6 are aligned using an image recognition device 50, and the panel and the base sheet 6 are bonded together. After completion of the bonding, the UV sheet 29, which is a terminal protection tape, is applied by the terminal protection tape application roller 51 while moving the base sheet 6.
[0043]
(6) When the base sheet 6 further moves, the panel enters the etching tank 52, and the substrate 11 is etched using an etching solution made of an aqueous solution of hydrofluoric acid. Thereafter, when the base sheet 6 further moves, the panel enters the cleaning tank 53, the UV sheet 29 is peeled off, the resin applied and cured around the panel is removed with a release agent, rinsed with pure water, Dried.
[0044]
In this way, the thinned substrate 1a attached to the base sheet 6, the barrier layer 2, the functional element layer 3, the liquid crystal layer 25, the color filter layer 13, the layer composed of the barrier layer 12, and the thinned substrate. 11a remains. That is, the thinned panel 33 remains. The substrate 11 may be partially removed completely.
[0045]
(7) If the base sheet 6 is further moved after the panel is thinned, the process proceeds to the mounting process. In the mounting process, a substrate 27 such as a flexible substrate or a TAB (Tape Automated Bonding) tape is connected to the panel 33 by the substrate connector 54 shown in FIG.
[0046]
(8) The cover film application roller 55 attaches the cover film 16 onto the thin substrate 11a of the panel 33 to which the substrate 27 is connected by the adhesive layer 15 made of an adhesive resin. By applying a polarizing plate, a diffusing plate, a lens sheet, or a prism sheet as the cover film 16, the number of members can be reduced and the cost can be reduced. Next, the process proceeds to the dividing step. The base sheet 6 is cut by the panel cutting machine 56. In this way, the liquid crystal panel 34 is obtained.
[0047]
In this embodiment, when manufacturing a liquid crystal panel having TFTs formed on a substrate, functional elements are formed and processed using a substrate made of heat-resistant glass having excellent characteristics such as heat resistance and corrosion resistance. The liquid crystal panel having excellent reliability and portability can be manufactured at the same time. Since this liquid crystal panel is a functional panel that is light, withstands deformation, and does not break even when dropped, it can be used as an information portable terminal display such as a portable mobile phone or a cellular phone.
[0048]
In this embodiment, since the etching process, the mounting process, and the dividing process are continuously performed by a roll-to-roll method, the operation of discharging, moving, and supplying the panel from process to process is eliminated, and a transfer unit such as a cassette is provided. do not need. Furthermore, in this embodiment, since the base sheet for conveyance is made into the panel sheet of a final shape, the sheet only for conveyance is not required.
[0049]
Glass having a thickness of 0.5 mm or less is quite fragile, but a substrate rich in dimensional stability, heat resistance and bending rigidity can be formed by forming a thin glass layer and a resin layer. By making a glass substrate or the like a thickness of 100 μm or less and bonding and reinforcing a flexible substrate such as a resin, the following effects can be obtained. Even if a card-type calculator or TV product is placed in a pocket and any external pressure is applied, bending does not occur and the product does not break. Curved and fixed products such as large screens or car dashboards can be made. When producing by roll-to-roll method, there are few cracks and productivity improves.
[0050]
The barrier layer formed on the substrate made of glass serves as a stopper when the substrate is thinned, and enables the substrate to be uniformly thinned. A barrier layer made of a metal oxide is harder than glass, has chemical resistance, and can protect a functional element. As the barrier layer, in addition to tantalum oxide, an oxide of metal such as titanium or tungsten can be used. Several layers may be used as a barrier layer. Alternatively, a barrier layer may be formed by combining a plurality of metal oxides.
[0051]
As a method of reducing the thickness of the substrate, besides etching, a method of mechanically polishing and scraping the substrate, a method of mechanically and chemically polishing the substrate by using both mechanical polishing and etching, and blasting A method of scraping the substrate can be applied. Further, the substrate may be thinned by controlling the etching rate of the substrate by strictly controlling the temperature and concentration of the etching solution, the stirring method, etc. without providing the barrier layer. Of the two substrates included in the panel, one substrate may not be thinned, and only the other substrate may be thinned.
[0052]
In this embodiment, a thin panel is attached to a base sheet only from one side, but after thinning the panel from both sides, an organic polymer can be attached to both sides of the panel to produce a functional panel. . In this embodiment, the panel is affixed to the base sheet. However, a solvent such as a flexible organic polymer can be applied and cured using a spin coater or a slot coater.
[0053]
In addition to various resins, the flexible base sheet may be a metal film such as aluminum or copper, or a multilayer film of metal and resin. The base sheet may be selected for the purpose of improving rigidity or cooling property or shielding electromagnetic waves.
[0054]
As described above, a functional panel having properties required for a product that is light, withstands deformation, and does not break even when dropped is manufactured by using a conventional manufacturing method as it is. The functional panel manufacturing method of this embodiment can manufacture not only a liquid crystal panel but also other flat display devices or thin film integrated circuit devices.
[0055]
FIG. 3 is a schematic view showing a manufacturing process of a functional panel 60 according to another embodiment of the present invention.
[0056]
First, in accordance with the steps (1) to (6) in FIG. 1, the panel is etched on one side, attached to the base sheet 6, etched on the remaining side, washed, dried, and the like. After the thinning of the panel is completed, the two panels 40 and 41 that are adjacent to each other are made into one set, and the gate terminals are connected 42 to each other. Next, the gate substrate 43 is connected to the common gate terminal of the two panels 40 and 41, and the source substrates 44 and 45 are connected to the respective panels. The gate substrate 43 drives the two panels 40 and 41. Next, the cover film 16 is bonded together by an adhesive layer made of an adhesive resin. Then, an energization test or a display quality test is performed in the inspection process, and the sheet is divided into a set of two sheets. Thus, the functional panel 60 is completed.
[0057]
FIG. 4 is a diagram showing a two-screen integrated display device 70 including the functional panel 60 manufactured as described above.
[0058]
A conventional two-screen integrated display device uses two casing panel modules that are docked with a hinge or the like. Therefore, the conventional two-screen integrated display device has a frame portion or a hinge portion of the case, and there is an area that cannot be displayed between the two panels, so that it is difficult to display continuous images or characters. On the other hand, since the two-screen integrated display device 70 using a flexible sheet is made of two sheets with one sheet, as shown in FIG. 4, movable parts such as a frame portion and a hinge are used. Do not need. In the two-screen integrated display device 70 using a flexible sheet, only the connection exists between the two panels, and the two panels can be connected. Further, since the two-screen integrated display device 70 using a flexible sheet can be easily folded between two panels, it is necessary to spread the display when displaying an image and display the image. When not, you can fold it up and put it in your pocket.
[0059]
By producing in a roll-to-roll system, it is possible to produce not only a two-screen integrated type but also a multi-screen integrated display device such as a three-screen or four-screen type. FIG. 5 is a diagram showing a four-screen integrated multi-screen 71. If a plurality of consecutive panels are connected to form a common circuit, the plurality of panels can be controlled collectively. In this way, a large curved multi-screen can be realized. It is also possible to manufacture a product with a curved small screen.
[0060]
【The invention's effect】
As described above, according to the present invention, it is possible to transfer a functional element to various transfer bodies without particularly selecting a transfer body. For example, by forming a functional device having characteristics that have not been obtained in the past by transferring the functional element to a substrate where the functional element cannot be directly formed or it is difficult to directly form the functional element. Can do. In particular, when manufacturing a liquid crystal panel in which TFTs are formed on a transparent substrate, functional thin films are formed and processed using a substrate such as heat-resistant glass having excellent heat resistance and corrosion resistance, and organic polymers, etc. By transferring the functional thin film onto a lightweight substrate having excellent impact resistance, a liquid crystal display having excellent reliability and portability can be easily produced. Such advantages are similarly enjoyed not only in the production of liquid crystal displays but also in the production of other flat display devices or thin film integrated circuit devices.
[0061]
In addition, by using a flexible transfer body, for example, if a plurality of screens such as 2 screens or 3 screens are manufactured in an integrated form and can be folded for each screen, the screen can be folded and used. Sometimes it is possible to make a large screen. In the future, electronic paper will be realized. Further, by integrally forming the two screens, it is possible to control the two screens with a single gate substrate, leading to a reduction in member costs.
[0062]
If a functional panel is produced by a roll-to-roll method, each process such as an etching process, a mounting process, or an inspection process can be continuously performed. Production of functional panels using the roll-to-roll method eliminates the process of discharging, transferring, or supplying panels from process to process, eliminating the need for cassettes and other means of transport, and is therefore effective in reducing capital investment and reducing costs. There is.
[0063]
When the functional panel is produced by the roll-to-roll method, the sheet for conveyance is made into a final-shaped panel sheet, so that a sheet only for conveyance is not necessary. Since the sheet is cut to form a single panel after the conveyance is completed, the work efficiency is improved and the cost can be reduced.
[0064]
Further, according to the present invention, a highly reliable display that can withstand light deformation and does not break even when dropped can be manufactured as an information portable terminal display such as a portable mobile phone or a cellular phone.
[Brief description of the drawings]
FIG. 1 is a process diagram in the case of manufacturing a liquid crystal panel using a method for manufacturing a functional panel according to an embodiment of the present invention.
FIG. 2 is a schematic view showing a roll-to-roll process in the manufacturing process of the liquid crystal panel 34. FIG.
FIG. 3 is a schematic view showing a manufacturing process of the functional panel 60. FIG.
4 is a diagram showing a two-screen integrated display device 70 including a functional panel 60. FIG.
FIG. 5 is a diagram showing a four-screen integrated multi-screen 71;
[Explanation of symbols]
1, 11 Substrate 1a, 11a Thinned substrate 2, 12 Barrier layer 3 Functional element layer 13 Color filter layer 10 Functional element substrate 20 Color filter substrate 5, 15 Adhesive layer 6 Base sheet 25 Liquid crystal layer 26, 29 UV sheet 27 Substrate 28 Resin 30, 31, 32, 33 Panel 34 Liquid crystal panel

Claims (5)

Reinforcement that thins the substrate by reducing the thickness from the back side of the glass substrate on which the functional elements are formed on the surface, and has flexibility in reinforcing the thinned substrate. Paste the layers ,
The reinforcing layer is a strip-shaped sheet, and further performs at least one of washing, substrate mounting, and cutting while the substrate is attached, while continuously feeding the sheet,
And for substrate protection or panel terminal protection, a protective film of varying adhesive force by ultraviolet irradiation, the production method of the functional panel according to claim paste it while feeding the sheet.   The method for producing a functional panel according to claim 1, wherein a barrier layer that protects the functional element when the substrate is thinned is formed between the functional element and the substrate.   The method for manufacturing a functional panel according to claim 2, wherein the barrier layer is made of a metal oxide.   The method for manufacturing a functional panel according to claim 1, wherein the reinforcing layer is made of an organic polymer. By dividing the sheet leaving at least two panels adjacent affixed to sheet, it claims 1-4, characterized in that to produce a functional panel in which a plurality of panels are integrated by connecting The manufacturing method of the functional panel as described in any one of these.

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