Electronic display device and method of manufacturing the same

Abstract

To realize a method for economically providing a narrow-frame electronic display device with which it is possible to increase an area by tiling.SOLUTION: A polymer film 30 is passed to a substrate 15 together and a wiring layer 40 and an electronic display device 60 are formed on the polymer film 30, then a portion of the substrate corresponding to an outside of a display area is removed and furthermore portions of the polymer film adjacent to the display area are removed, with a flying lead projected directly from the display area or from close vicinity of the display area. Furthermore, the flying lead portion is bent and turned from a side face of the display device to the substrate rear face through a substrate side face, and a driver IC is mounted to the rear face of the substrate. This manufacturing method makes it possible to realize an extremely narrow-frame electronic display device and suppress joints from standing out when tiled.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a narrow-frame electronic display device, and more particularly to an electronic display device of a type in which a driver IC is mounted on the rear surface of a display panel. Hereinafter, the electronic display device may also be referred to simply as a display device.

[0002] The screen size of liquid crystal displays, OLEDs, self-luminous displays such as micro LEDs, and reflective displays such as electrophoretic displays is increasing. However, the manufacturing of these displays requires large-area microfabrication technology and a highly clean environment, and the construction of manufacturing factories requires huge costs. Even a single defective pixel in a display pixel can be a fatal defect in the product, so the yield of displays decreases as the screen size increases. Even if the occurrence frequency of defective pixels is 1 pixel per square meter, if the screen size of an electronic display device is 1 square meter, most of the products will be defective. However, if the product size is 10 cm square, i.e., 100 cm square, then the probability of there being only one defective product out of 100 products is 99 acceptable products.

[0003] In light of this, attempts are being made to realize large-area electronic display devices by tiling small and medium-sized electronic display devices. When tiling, the width of the frame of each electronic display device is important. If the frame is wide, the tiling joints will be noticeable, and the appeal of the large area will be diminished. The width of the frame depends on the arrangement of peripheral devices and parts, such as the driving circuits, mounted on the electronic display device. Generally, the driving circuit elements of a display device (driving ICs, hereafter also referred to as driver ICs or driver elements) are attached to the periphery of the display device using TABs, COFs, etc. A configuration has been proposed in which a TAB or COF using a bendable film base material is folded at the edge of the electronic display device, and the driving circuit is disposed on the side or back surface of the electronic display device (Patent Document 1, Patent Document 2). Recently, a configuration has been proposed in which an electronic display device section is formed on a polymer film, which is folded at the end, and the peripheral circuits, etc. are disposed on the back surface of the electronic display device, thereby making the electronic display device more compact (Patent Document 3, Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2987903 [Patent Document 2] Japanese Patent Application Publication No. 10-148839 [Patent Document 3] US Patent Application Publication No. 2018 / 0090702 [Patent Document 4] International Publication No. 2020 / 065910 Summary of the Invention [Problem to be solved by the invention]

[0005] In driver implementation using TAB or COF, it is common to use ACF (anisotropic conductive film) to connect the electrodes formed on the display device to the terminals of the TAB or COF for electrical connection with the electronic display device. In other words, since it is necessary to place electrodes for connection with the TAB or COF on the periphery of the electronic display device, the frame width cannot be narrower than the electrode width. On the other hand, in the method of producing the display part of the electronic display device on a film substrate and folding the edge to turn it over, after mounting the driver element, it is necessary to carry out processing that deforms the entire electronic display device, which may damage the driver element or the connection between the driver element and the electronic display device, etc. Furthermore, in order to mount the driver IC after processing that deforms the electronic display device on the film substrate, the pressure, heat, ultrasonic vibrations, etc., that occur when mounting the driver element are transmitted through the film substrate to the backplane side of the electronic display device, which may destroy the TFT of the electronic display device, which is a particularly delicate part. [Means for solving the problem]

[0006] In order to solve these problems, the inventors conducted intensive research and discovered an electronic display device structure and a manufacturing method thereof that can be manufactured using existing electronic display device manufacturing equipment, has a narrow frame, and can achieve a high yield rate in terms of the implementation of driving circuits, thereby arriving at the present invention.

[0007] That is, the present invention comprises the following: [1] An electronic display device, comprising: substrate, a first polymeric film adhered to a first surface of the substrate; an electronic display device formed on the first polymeric film; leads for supplying power and drive signals to said electronic display device; a second polymeric film adhered to a second surface of the substrate; drive circuitry mounted on said second polymeric film for driving said electronic display device; Including, An electronic display device, wherein a portion of the lead between a side surface of the electronic display device and a drive circuit element is a flying lead. [2] The electronic display device described in [1], characterized in that a portion of the flying leads is arranged parallel to the side of the substrate, and the length of the parallel section is 30% or more of the substrate thickness. [3] The electronic display device according to [1] or [2], wherein some or all of the flying leads are in contact with a side surface of the substrate. [4] The electronic display device according to any one of [1] to [3], wherein the second polymer film and a part or all of the second surface of the inorganic substrate are bonded via a silane coupling agent condensate layer. [5] The electronic display device according to any one of [1] to [4], wherein the first polymer film and a part or all of the first surface of the inorganic substrate are bonded via a silane coupling agent condensate layer. [6] (a) providing a laminate having a substrate and a polymeric film adhered to at least one side of the substrate; (b) forming an electronic display device and leads on the polymeric film; (c) removing the substrate outside the area in which the electronic display device is formed; and removing a part of the polymer film in the area where the leads are formed to form flying leads. A process of forming each region having the following layer configuration through the steps of: Layer structure of area 1 (display area): electronic display device / polymer film / adhesive layer / substrate Layer structure of region 2 (first wiring region adjacent to region 1): lead / polymer film Layer structure of area 3 (flying lead area): Lead Layer structure of region 4 (second wiring region adjacent to region 3): lead / polymer film (d) bending region 3 (the flying lead region) along the side of the substrate; (e) bending region 4 (second wiring region) along the second surface of the substrate and bonding it to the second surface of the substrate; A method for manufacturing an electronic display device having at least the above-mentioned features. [7] The method for producing an electronic display device according to [6], wherein the step of removing a portion of the polymer film is a plasma etching method. [8] The method for producing an electronic display device according to [6], wherein the step of removing a portion of the polymer film is a sandblasting method. [9] The method for manufacturing an electronic display device according to [6], wherein the step of removing a portion of the polymer film is performed by mechanical grinding.

[10] The method for producing an electronic display device according to [6], wherein the step of removing a portion of the polymer film is an etching method using a solution of an alkaline compound.

[11] The method for producing an electronic display device according to any one of [6] to

[10] , wherein the region 2 is omitted and the region 1 and the region 3 are directly adjacent to each other. Effect of the Invention

[0008] According to the structure of the present invention, since no electrode area is required to connect the TAB or COF to the electronic display device section, it is possible to extract the leads from very close to the display section of the electronic display device, and by making the lead section into a flying lead, it is possible to bend the leads directly from very close to the display section or from the side of the display section, making it possible to essentially narrow the frame width of the electronic display device to about the thickness of the leads. By using a hard inorganic substrate such as a glass plate as the substrate and preferably by making the adhesive layer thin, the mounting yield of the driver IC can be improved significantly. Preferably, the driver IC can be mounted after the region 4 is bonded to the back side of the substrate, which makes it possible to reduce product defects that occur after the driver IC is mounted.

[0009] In the present invention, a part or the whole of the polymer film is preferably adhered to the substrate via a silane coupling agent condensate. The presence of the silane coupling agent condensate layer is the result of the silane coupling agent treatment. The thickness of the silane coupling agent condensate layer is extremely thin, and is at a level that can be practically ignored when compared with the thickness of the substrate and the polymer film. Therefore, the flatness of the polymer film layer is almost controlled by the substrate, so that an extremely smooth surface can be obtained. This is an essential characteristic in the formation of electronic display devices that require large-area, high-precision processing. When the polymer film is used without a support (substrate) or is adhered to the substrate with a general adhesive or pressure-sensitive adhesive having a thickness of several μm to several tens of μm, undulations occur on the polymer film surface when the polymer film is folded, and the presence of this undulation can be fatal in microfabrication that requires extremely precise exposure operations.

[0010] The heat resistance of the silane coupling agent condensate layer is higher than that of adhesives made of general organic substances, and can fully withstand high temperature environments in various processes for forming electronic display devices, more specifically, in processes for forming amorphous silicon thin films, polysilicon thin films, oxide semiconductor thin films, compound semiconductor films, etc. Furthermore, it can fully withstand chemicals, solvents, plasma processing, etc. used in processing processes such as exposure, development, etching, and resist peeling. Therefore, the electronic display device of the present invention can directly perform processing required for electronic display devices on the polymer film of the laminate obtained by laminating a polymer film on a substrate via a silane coupling agent condensate layer. According to this processing method, it is possible to treat the flexible film as if it were a single substrate and perform the processing using a conventional electronic display device manufacturing device. The present invention can also be applied to a process in which a solution of a polymer precursor (a typical example is polyamic acid, a precursor of polyimide) is applied to a substrate, and then dried and cured to form a polymer film on the substrate, by precisely controlling the thickness. [Brief description of the drawings]

[0011] [Figure 1] Fig. 1 is a schematic diagram showing a cross-sectional configuration of one embodiment of the electronic display device of the present invention. The leads on the side of the electronic display device are flying leads. In the embodiment of Fig. 1, polymer films are bonded to both the first and second surfaces of the substrate via a silane coupling agent layer. [Diagram 2] Fig. 2 is a schematic diagram showing a cross-sectional configuration of one embodiment of the electronic display device of the present invention. The leads on the side of the electronic display device are flying leads. In the embodiment of Fig. 2, the first surface of the substrate and the polymer film are bonded via a silane coupling agent layer, and the second surface and the polymer film are bonded by an adhesive. [Diagram 3] Fig. 3 is a schematic diagram showing a cross-sectional configuration of one embodiment of the electronic display device of the present invention. The leads on the side of the electronic display device are flying leads. In the embodiment of Fig. 3, the first surface of the substrate and the polymer film are bonded with an adhesive, and the second surface and the polymer film are bonded via a silane coupling agent condensate layer. [Figure 4] 4 is a schematic diagram showing a cross-sectional structure of one embodiment of the electronic display device of the present invention, in which all of the flying leads are in contact with the side surfaces of the substrate. [Diagram 5] FIG. 5 shows an embodiment in which no flying lead portion is provided. [Figure 6] FIG. 6 is a diagram illustrating the first half of an example of a manufacturing process for the electronic display device of the present invention when a film lamination method is used. [Figure 7] 7 is a diagram for explaining the latter half of an example of the manufacturing process of the electronic display device of the present invention when a film lamination method is used, and regions 1 to 4 are also shown. [Figure 8] FIG. 8 is a diagram illustrating the first half of an example of a manufacturing process for an electronic display device of the present invention when a varnish method is used. [Figure 9]9 is a diagram for explaining the latter half of an example of the manufacturing process of the electronic display device of the present invention when using the varnish method. Also shown are regions 1 to 4. However, the figure shows a case where region 2 is not provided. [Figure 10] 10 is a schematic diagram showing the details of the side portion of the electronic display device of the present invention, with the silane coupling agent layer, adhesive layer, driver IC, etc. omitted. [Figure 11] FIG. 11 is a schematic diagram showing details of the side portion of the electronic display device of the present invention, showing a state in which a small amount of the polymer film is left in the vicinity of the display device to form region 2. In FIG. [Figure 12] FIG. 12 is a schematic diagram showing the details of the side portion of the electronic display device of the present invention, showing the state when the gap portion is filled with resin. [Figure 13] FIG. 13 is a schematic diagram showing details of the side portion of the electronic display device of the present invention, in which there is essentially no gap and furthermore the polymer film located on the side of the substrate has been completely removed, resulting in the wiring portion being a flying lead. [Figure 14] FIG. 14 is a schematic diagram showing details of the side portion of the electronic display device of the present invention, in which there is substantially no gap, the side of the substrate is made into a flying lead, and the dimensions of the display portion of the electronic display device are larger than the dimensions of the substrate. [Figure 15] FIG. 15 is a schematic diagram showing a case where a driver IC is mounted using a conventional TAB. [Figure 16] FIG. 16 is a schematic diagram showing the configuration of a side portion of one example of an electronic display device that has been proposed in the past. [Figure 17] FIG. 17 is a layout diagram of a simulated display device used in an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram showing the cross-sectional structure of a representative embodiment of an electronic display device according to the present invention. Substrate 15 is the key element that supports the entire electronic display device of the present invention. As the substrate, organic substrates such as polymer plates and polymer sheets, composite substrates such as glass fiber reinforced resin substrates, inorganic filler reinforced resin substrates, and carbon fiber reinforced resin substrates, glass substrates, metal substrates, metal foils, silicon wafers, and other inorganic substrates such as semiconductor wafers can be used. For practical purposes, flat substrates can be used. Flexible glass having a thickness of about tens of μm can also be used as the substrate. The preferred thickness of the inorganic substrate 15 is 20 μm or more, more preferably 45 μm or more, and even more preferably 300 μm or more. In addition, it is preferably 5 mm or less, more preferably 1.2 mm or less, and even more preferably 0.7 mm or less. By setting the thickness of the inorganic substrate within the above range, durability and handling properties are improved. Glass substrates include quartz glass, high silicate glass (96% silica), soda-lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex (registered trademark)), borosilicate glass (alkali-free), borosilicate glass (microsheet), aluminosilicate glass, etc. Among these, those with a linear expansion coefficient of 5 ppm / °C or less are preferable, and commercially available products such as liquid crystal glass "Corning (registered trademark) 7059", "Corning (registered trademark) 1737", and "EAGLE" manufactured by Corning Incorporated, "AN100" manufactured by Asahi Glass Co., Ltd., "OA10" manufactured by Nippon Electric Glass Co., Ltd., and "AF32" manufactured by SCHOTT are preferable. Furthermore, these inorganic substrates, preferably substrates having a thin film formed on the surface thereof, of metals such as chromium, nickel, nichrome, molybdenum, and tungsten, metal oxides, metal nitrides, silicon nitride, aluminum nitride, and silicon carbide, may also be used. Also usable are metal substrates or metal foils having an anodized film formed on the surface, and inorganic substrates having a fluororesin coating or silicone resin coating. Examples of resins that can be used for the organic substrate and composite substrate include epoxy resin, polyimide resin, phenol resin, melamine resin, crosslinked polyester resin, polyether ether ketone resin, bismaleimide triazine resin, and crosslinked acrylic resin.

[0013] <Polymer film> The polymer film 30 may be made of a film such as polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, wholly aromatic polyester, other copolymer polyester, polymethyl methacrylate, other copolymer acrylate, polycarbonate, polyamide, polysulfone, polyether sulfone, polyether ketone, polyamide imide, polyether imide, aromatic polyimide, alicyclic polyimide, fluorinated polyimide, cellulose acetate, cellulose nitrate, aromatic polyamide, polyvinyl chloride, polyphenol, polyarylate, polyphenylene sulfide, polyphenylene oxide, polystyrene, liquid crystal polymer, etc. In the present invention, the first polymer film and the second polymer film are collectively referred to as the polymer film. Among these polymer films, the present invention prefers polymer films obtained by condensation polymerization reaction (condensation polymer films). Particularly effective and useful in the present invention are polymers having heat resistance of 100°C or higher, preferably 150°C or higher, so-called engineering plastic films. Here, heat resistance refers to the property of having a glass transition temperature or heat distortion temperature of 100°C or higher (preferably 150°C or higher). Condensation polymerization polymer films (condensation polymer films) preferably used in the present invention are polyester, polyamide, polyamideimide, polyimide, polybenzazole, polyimidebenzazole, polyethylene naphthalate film, and liquid crystal polymer film, and more preferably polyimide film, polyethylene naphthalate film, or liquid crystal polymer film.

[0014] The polymer films preferably used in the present invention are polyimide films, polyamide films, polyamideimide films, polybenzoxazole films, and polyimidebenzoxazole films, and aromatic polyimides, alicyclic polyimides, polyamideimides, polyetherimides, etc. can be used. When the present invention is used particularly for manufacturing a flexible display element, it is preferable to use a colorless and transparent polyimide-based resin film, but this is not particularly limited when forming a rear element of a reflective or self-luminous display.

[0015] In general, a polyimide film is obtained by applying a polyamic acid (polyimide precursor) solution obtained by reacting diamines with tetracarboxylic acids in a solvent onto a support for producing a polyimide film, drying the solution to form a green film (also called a "precursor film" or "polyamic acid film"), and then subjecting the green film to high-temperature heat treatment on the support for producing a polyimide film or after being peeled off from the support to cause a dehydration ring-closing reaction. The polyimide film preferably used in the present invention is, for example, a polyimide film obtained from a polyimide resin having the following chemical composition. Polyimide resin obtained from pyromellitic acid and diaminodiphenyl ether, Polyimide resin obtained from biphenyltetracarboxylic acid and phenylenediamine, Polyimide resin obtained from pyromellitic acid and phenylenediamine, Polyimide resins using diamine compounds having a benzoxazole skeleton as the diamine component, Polyimide resins using cyclohexyltetracarboxylic acid and cyclobutanetetracarboxylic acid, Polyimide resin using alicyclic tetracarboxylic acid and aromatic diamine with amide bond Polyimide resins using monomers containing fluorine, Polyimide resin using monomers containing ions These are examples of the main components of the tetracarboxylic acid or diamine, respectively, and it is also possible to use polyimide resins copolymerized by blending a second or third component, polyimide resins polymerized by combining polyimides of multiple compositions, polyimide resins polymer blended or alloyed, and polyimide resins into which inorganic fillers or polydimethylsiloxane components have been introduced. It is also possible to use polyimide films having a structure in which polyimide resins of different compositions are laminated in the thickness direction.

[0016] In the present invention, it is preferable to use a polyimide film having an elastic modulus of preferably 3 GPa or more, more preferably 4 GPa or more, even more preferably 5 GPa or more, and preferably 15 GPa or less, even more preferably 12 GPa or less, as the polymer film. If the elastic modulus is within this range, bending at the edge of the substrate is possible, and damage to the wiring layer can be minimized. If the elastic modulus is lower than this range, the polymer film may be significantly deformed when bending, which may cause breakage of the wiring layer. On the other hand, if the elastic modulus is too high, bending may be difficult. The polymer film of the present invention is preferably a polyimide film having a breaking elongation of 3% or more, preferably 5% or more, more preferably 7% or more, and even more preferably 9% or more. The breaking elongation is also a measure of foldability, and if the breaking elongation is low, the film is brittle and easily cracked, so that cracks may occur when the film is bent, but if the breaking elongation is 5% or more, the film can be bent. Furthermore, the polymer film of the present invention is preferably a polyimide film having a thickness of 3 μm to 75 μm. The film thickness is preferably 6 μm or more, and more preferably 12 μm or more. The upper limit is preferably 60 μm, and more preferably 45 μm or less. The film thickness is related to the foldability, and if it is within a certain range, folding becomes relatively easy. Furthermore, the linear expansion coefficient of the polymer film of the present invention is 35 ppm / K or less, preferably 18 ppm / K or less, more preferably 9 ppm / K or less. The lower limit of the linear expansion coefficient is -5 ppm / K, preferably -2 ppm / K. Furthermore, it is preferable that the difference in the linear expansion coefficient between the polymer film and the substrate is 10 ppm / K or less. By keeping the linear expansion coefficient within a predetermined range, warping of the laminate is suppressed and the defective rate during production is reduced.

[0017] In the present invention, in order to fold the polymer film along the side surface of the substrate without stress, it is preferable to adjust the compressive strength of the polymer film to be weaker than the tensile strength of the polymer film. Specifically, for example, voids may be intentionally formed in the polymer film to make it more likely to buckle under compressive stress.

[0018] In the present invention, the polymer film is preferably a polyimide film having a total light transmittance of 85% or more and a yellow index of 5 or less. The total light transmittance is preferably 88% or more, more preferably 91% or more. There is no particular upper limit, but 99% or more is sufficient for use in electronic display devices, and 98% or less is also acceptable. The yellow index is preferably 4 or less, more preferably 3 or less. This means that the polyimide film has colorless transparency. There is no particular lower limit for the yellow index, but 1 or more is sufficient for use in electronic display devices. When a polyimide film having colorless transparency is used, the present invention can be applied to liquid crystal electronic display devices, which are light-transmitting display systems.

[0019] In a preferred method for producing the electronic display device of the present invention, a laminate in which a substrate and a polymer film are bonded together is obtained during the process. Examples of techniques for obtaining such a laminate include a film lamination method and a varnish method.

[0020] <Film lamination method> A polymer film and a substrate are bonded together with an adhesive or a pressure sensitive adhesive to obtain a laminate. Epoxy adhesives, silicone adhesives, acrylic adhesives, and pressure sensitive adhesives can be used as adhesives. However, when a high temperature process is applied to the formation of an electronic display device, it is necessary to use a highly heat resistant adhesive. Furthermore, in the present invention, a method of bonding a substrate and a polymer film via a silane coupling agent condensate can be used as a highly heat resistant bonding method. When high temperatures are required to form an electronic display device, the substrate is also required to be heat resistant, so it is preferable to use it in combination with an inorganic substrate, preferably a glass substrate. In the adhesion method using a silane coupling agent, the silane coupling agent is applied to either or both of the adhesive surfaces of the polymer film or the substrate, and the two are then superimposed and heated. The organic group of the silane coupling agent reacts with the polymer film surface, and the methoxy group and ethoxy group of the silane coupling agent react with the hydroxyl group on the inorganic substrate surface, and the silane couplings self-condense to form a condensate layer, thereby performing adhesion. In this method, for example, by combining with the technology disclosed in Patent Publication No. 5224011, it is possible to control the adhesive strength and form a pattern of parts with strong and weak adhesive strength, and it can be applied in situations where the substrate and the polymer film are partially peeled off.

[0021] <Varnish method> This method involves applying a resin solution that constitutes a polymer film or a polymer precursor solution to a substrate, drying it on the substrate, and carrying out a chemical reaction as necessary to obtain a polymer film. A typical example is the use of a polyimide resin solution or a solution of polyamic acid, which is a polyimide precursor, to obtain a polyimide film. In the varnish method, for example, using the technique disclosed in Japanese Patent No. 5,862,866, it is possible to control the adhesive strength between the substrate and the polymer film and form a pattern of areas with strong and weak adhesive strength.

[0022] The properties of the polymer film specified in the present invention were determined by the following methods. <Substrate thickness, polymer film thickness> The thickness of the polymer film was measured using a micrometer ("Millitron 1245D" manufactured by Fine Leaf Co., Ltd.) and the average value of 10 points was calculated.

[0023] <Tensile modulus, tensile strength at break and tensile elongation at break of polymer film> From the polymer film to be measured, rectangular test pieces measuring 100 mm x 10 mm in the machine direction (MD) and width direction (TD) were cut out, and the tensile modulus, tensile breaking strength, and tensile breaking elongation were measured in each of the MD and TD directions using a tensile testing machine (Shimadzu Corporation, "Autograph (registered trademark); model name AG-5000A") at a tensile speed of 50 mm / min and a chuck distance of 40 mm, and the average value of all the measured values ​​in the MD and TD directions was obtained.

[0024] <Coefficient of linear expansion (CTE) of polymer film> The expansion / contraction rate was measured under the following conditions for the machine direction (MD) and width direction (TD) of the polymer film to be measured, and the expansion / contraction rate / temperature was measured at 15°C intervals (30°C to 45°C, 45°C to 60°C, ...). This measurement was performed up to 300°C, and the average value of all the measured values ​​in the MD and TD directions was calculated as the coefficient of linear expansion (CTE). Device name: MAC Science "TMA4000S" Sample length: 20mm Sample width: 2mm Heating start temperature: 25℃ Heating end temperature: 400℃ Heating rate: 5℃ / min Atmosphere: Argon Initial load; 34.5g / mm2 <Total light transmittance> The total light transmittance (TT) of the film was measured using a HAZEMETER (NDH5000, manufactured by Nippon Denshoku Co., Ltd.). A D65 lamp was used as the light source. The same measurement was performed three times, and the arithmetic average value was used.

[0025] <Yellow Index> Using a color meter (ZE6000, Nippon Denshoku) and a C2 light source, the tristimulus values ​​XYZ of the film were measured according to ASTM D1925, and the yellowness index (YI) was calculated according to the following formula. The same measurement was performed three times, and the arithmetic average value was used. YI=100×(1.28X-1.06Z) / Y

[0026] <Silane coupling agent condensation product layer> The silane coupling agent condensate layer 20 is literally a layer made of a condensate of a silane coupling agent. The silane coupling agent layer functions to bond the substrate and the polymer film. A part or the whole of the adhesive surface of the polymer film and the substrate is bonded via the silane coupling agent condensate layer. The silane coupling agent condensate layer is preferably present on the first surface and / or the second surface of the substrate, and more preferably present on the first surface and the second surface of the substrate. It is further preferable that the silane coupling agent condensate layer is present on the whole of the first surface and the whole of the second surface of the substrate. It is also preferable that the polymer film and the side surface of the substrate are bonded via the silane coupling agent condensate layer. Silane coupling agents are a general term for compounds that make inorganic surfaces organic through a dealcoholization condensation reaction between hydroxyl groups present mainly on inorganic surfaces and methoxy groups, ethoxy groups, etc. contained in the molecules of the silane coupling agents. Such dealcoholization reactions also occur between silane coupling agents, resulting in a condensation product in which the silane coupling agents are linked by siloxane bonds.

[0027] In the present invention, the silane coupling agent is preferably a compound containing 10% by mass or more of Si (silicon).Furthermore, it is preferable that the silane coupling agent has an alkoxy group in the structure.Specific examples of the silane coupling agent that can be preferably used in the present invention include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, etc.

[0028] Among the above-mentioned silane coupling agents, silane coupling agents having one silicon atom in one molecule are particularly preferred, such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, etc. When particularly high heat resistance is required in the process, it is desirable to use one in which Si and amino group are connected by an aromatic group. In addition to the above, 11-amino-1-undecenethiol can also be used as the above-mentioned coupling agent.

[0029] Silane coupling agents are generally liquids, and are applied to a substrate or polymer film to obtain a layer by a gas-phase application method such as wet coating or vapor deposition. As a method for wet-coating the silane coupling agent, a stock solution of the silane coupling agent or a solution diluted with a solvent such as an alcohol solution or an aqueous solution can be used appropriately using a conventionally known solution application means (conventionally known application device) such as a spin coating method, curtain coating method, dip coating method, slit die coating method, gravure coating method, bar coating method, comma coating method, applicator method, screen printing method, or spray coating method. In addition, the silane coupling agent can be spot-applied using a dispenser, a dropper, or a brush.

[0030] The silane coupling agent layer can also be applied through a gas phase, such as by a vapor deposition method. Specifically, the substrate or polymer film is exposed to the vapor of the silane coupling agent, i.e., the silane coupling agent is substantially in a gaseous state, to form the layer. The vapor of the silane coupling agent can be obtained by heating the liquid silane coupling agent to a temperature of 40°C to the boiling point of the silane coupling agent. The boiling point of the silane coupling agent varies depending on the chemical structure, but is generally in the range of 100 to 250°C. However, heating to 200°C or higher is not preferred because it may cause a side reaction on the organic group side of the silane coupling agent. The silane coupling agent may also be applied to both sides of the substrate or polymer film.

[0031] <Lead> The lead 40 is formed on the surface of the non-adhesive side of the polymer film 30, and is a wiring that electrically connects (contacts) the electronic display device and the driving element (driver IC). The lead is connected to a wiring layer that is spread like a mesh inside the electronic display device, and the electronic display device has a multi-layer wiring structure, but for convenience, the figure shows only the part arranged from the peripheral part of the electronic display device to the outer periphery of the electronic display device. In principle, the wiring layer is preferably a metal layer, and mainly copper, silver, aluminum, gold, silver, nickel, chromium, tin, lead, etc., which have high conductivity, or molybdenum, tungsten, etc., which have low linear expansion coefficients, are used. Furthermore, alloys such as brass, cupro-nickel, bronze, invar, stainless steel, and solder may be used as needed. Such a wiring layer is formed by vacuum metallizing techniques such as deposition and sputtering, wet metallizing techniques such as electroless plating, or metallizing techniques such as plasma spraying, either alone or in combination. Furthermore, the wiring layer is patterned by etching, masking, or the like. Although omitted in the drawings for simplification, the wiring layer is preferably insulated and protected by a resin etc. The upper, lower and side surfaces of the wiring layer are preferably insulated and protected.

[0032] <Driver circuit element (driver IC)> The driving circuit element (driver IC) 50 of the electronic display device is an integrated electronic circuit element that supplies image signals and power to the electronic display device. The driver IC may be a conventional semiconductor element, and is preferably mounted in the form of a bare chip. The driver IC 50 is mounted (mounted) on the surface of the polymer film that is attached to the second surface of the inorganic substrate. Although not shown in the figure, in the case of face-down bonding, bumps for connection are formed on the electrodes extending from the leads. In the case of face-up bonding, a surface treatment suitable for wire bonding is applied to the wiring layer. It is a preferred embodiment to perform gold plating, tin plating, or the like as the surface treatment of the wiring layer. After mounting the driver IC, an underfill agent, an overcoat, or a pod sealing may be applied.

[0033] <Electronic display device> The electronic display device 60 in the present invention refers to an electronic display device generally called FPD: flat panel display, such as a liquid crystal display device, an OLED (organic electroluminescence element), a micro LED array, an electrophoretic display, etc., and is a part that displays images in the electronic display device of the present invention. It does not include a CRT (cathode ray tube). In principle, it can also be applied to FED, PDP, fluorescent display tube, etc. The present invention is preferably combined with a large-area technology by tiling, and is preferably combined with a self-luminous OLED, a micro LED array, or a reflective display device such as an electrophoretic electronic display device or a reflective liquid crystal display device. The electronic display device 60 is formed on the surface of the non-adhesive side of the polymer film on the side that is adhered to the first surface of the inorganic substrate. In other words, it is preferably constructed on the surface of the polymer film. Generally, an electronic display device is composed of a backplane and a frontplane. The following process is exemplified as an example of the formation of an electronic display device in the present invention. First, a gas barrier film, an anchor layer, etc. are formed as necessary on the non-adhesive surface of a polymer film adhered to a substrate, and then thin-film semiconductor elements and pixel drive electrodes that directly handle each pixel signal are formed, light-emitting bodies or electrophoretic bodies are arranged, and then a frontplane equipped with a facing electrode or a color filter as necessary is formed in a build-up manner, or a separately prepared frontplane is attached to obtain an electronic display device. As is well known, an electronic display device is a collection of individual pixels. In this invention, the pixel dimension of an electronic display device (hereinafter also referred to as pixel size or pixel dimension) is defined as Lpx. The pixel dimension can be calculated by dividing the dimension of the electronic display device in either the X or Y direction by the number of pixels constituting the same direction. When three pixels of RGB colors exist in one pixel for color display, RGB are counted as one pixel. In a reflective display, for example, when four colors of YMCK exist in one pixel, YMCK are counted together as one pixel.

[0034] <Adhesive layer> In the present invention, when it is necessary to bond the polymer film and the substrate without using a silane coupling agent, they may be bonded with an adhesive to form the adhesive layer 70. As the adhesive, it is preferable to use an adhesive having relatively high heat resistance, such as an epoxy resin-based or silicone resin-based adhesive that is commonly used in the electronics field. In the present invention, the adhesive preferably has a Si (silicon) content of less than 10 mass %. Furthermore, it is preferable that the adhesive does not have an alkoxy group in its structure.

[0035] <Casting resin> When a gap exists between the side of the substrate and the polymer film on the side of the electronic display device of the present invention, the gap is filled with the casting resin 90, thereby fixing the polymer film located on the side of the substrate and indirectly protecting the wiring layer formed on the polymer film. Epoxy resin, acrylic resin, silicone resin, urethane resin, phenolic resin, melamine resin, etc. can be used as the casting resin.

[0036] A process for producing the electronic display device of the present invention using a film lamination method will be described with reference to FIGS. Step A in FIG. 6 shows a substrate 15 before processing. Step B in Fig. 6 shows a state in which a silane coupling agent condensate layer 20 is formed on the surface of the substrate 15. However, the silane coupling agent is not completely condensed at this stage. At this stage, a preliminary treatment for forming a pattern of strong and weak adhesive strength as described in Japanese Patent No. 5224011 can be added. Step C in Fig. 6 shows the state where a polymer film 30 is further adhered. The adhesive surface of the polymer film is preferably chemically activated by plasma treatment or the like, that is, it is preferable to make it a state where functional groups with high chemical activity such as carboxyl groups, hydroxyl groups, amino groups, and carbonyl groups are present. The organic part of the silane coupling agent reacts with such functional groups, and the methoxy and ethoxy groups of one of the silane coupling agents react with hydroxyl groups on the surface of the substrate while undergoing a dealcoholization reaction, thereby adhering the two. The silane coupling agents also condense with each other to form a condensate layer. Steps A to C correspond to "(a) a step of preparing a laminate having a substrate and a polymer film adhered to at least one surface of the substrate." In step D of Fig. 6, leads are formed on the polymer film. For convenience, only the peripheral portion is shown. In step E of Figure 6, the electronic display device is formed. The leads are actually connected to a wiring layer that is arranged in a mesh pattern within the electronic display device. Steps D and E correspond to "(b) a step of forming an electronic display device and leads on a polymer film."

[0037] In step F of FIG. 6, a part of the substrate is removed. The part to be removed is outside the area where the electronic display device is formed, and it is preferable that the dimensions of the display area of ​​the electronic display device and the dimensions of the remaining substrate are the same, or the substrate dimensions are smaller within a range equivalent to the substrate thickness. This results in a polymer film with leads surrounding the periphery of the electronic display device in a frame-like form. To remove a specific part of the substrate, the substrate may be cut mechanically or by laser irradiation, or a notch may be created and then the substrate may be divided. In the case of a metal substrate, the relevant part may be removed by etching. In theory, the unnecessary part may be dissolved and removed even in the case of a substrate by using a strong alkali or hydrofluoric acid. Process G in FIG. 7 is a process in which the polymer film surrounding the electronic display device is removed from the opposite side of the surface on which the leads are formed, and the lead portion is made into a flying lead. Methods for removing the polymer film include plasma etching, sandblasting, other mechanical grinding methods, and etching using chemicals. If the polymer film is soluble in a solvent, an organic solvent can be used as the chemical. Condensation polymers such as polyester, polyimide, and polyamide can also be etched with a solution of an alkaline compound. Examples of solutions of alkaline compounds include aqueous alkaline solutions. Examples of alkalis include inorganic alkalis such as sodium hydroxide and potassium hydroxide, as well as organic alkalis such as ammonia, tetraalkylammonium hydroxide, and amino alcohols. Solutions of strong oxidizing agents such as potassium permanganate and sodium perchlorate can also be used. The steps F and G are "(c) a step of removing the substrate outside the region where the electronic display device is formed, and a step of removing a part of the region where the leads of the polymer film are formed to form a flying lead, thereby forming each region having the following layer structure: Layer structure of area 1 (display area): electronic display device / polymer film / adhesive layer / substrate Layer structure of region 2 (first wiring region adjacent to region 1): lead / polymer film Layer structure of area 3 (flying lead area): Lead The layer structure of the region 4 (the second wiring region adjacent to the region 3) corresponds to "lead / polymer film". In the illustration of step G in FIG. X1: Area 1 (display area) X2: Area 2 (first wiring area adjacent to Area 1) X3: Area 3 (flying lead area) X4: Area 4 (second wiring area adjacent to Area 3 = driver IC mounting area) It is.

[0038] In step H of Fig. 7, a silane coupling agent 21 is applied in advance to the second surface (rear surface) of the substrate where the polymer film side of the folded region 4 comes into contact. In this case, a necessary amount can be applied to the necessary area using a dispenser or the like. In a laboratory setting, it is also possible to apply the agent using a dropper or paintbrush. 7 shows a state in which the polymer film is folded and the corresponding portion of the polymer film is bonded to the second surface (rear surface) of the substrate via a silane coupling agent layer. In this case, as in steps A to C, the reaction of the silane coupling agent bonding the substrate and the polymer film and the self-condensation reaction proceed simultaneously in parallel to form a silane coupling agent layer. Steps H and I correspond to "(d) a step of bending region 3 (flying lead region) along the side of the substrate" and "(e) a step of bending and adhering region 4 (second wiring region) along the second surface of the substrate." FIG. 7J shows the state in which a driving circuit element (driver IC) for an electronic display device is mounted.

[0039] As a result of the above, it is possible to obtain an electronic display device having a configuration in which the wiring layer on the side surface is thinned, as shown generally in FIG. 1 (region 2 is omitted) and specifically in FIG. If region 3 is expanded and region 2 is omitted, the configuration will be as shown in detail in FIG. If the flying lead formation in step G is not performed, the configuration shown in FIG. 5, more specifically, the configuration shown in FIG. 16 will result, and the frame cannot be narrowed. Although the example shown here shows a case in which the polymer film is adhered to the inorganic substrate and the electronic display device portion is not peeled off from the inorganic substrate, but the inorganic substrate portion used in production is incorporated into the electronic display device, it is also possible to peel off the entire polymer film from the inorganic substrate at the stage where the process has progressed to step E, and re-adhere it to a newly prepared substrate of a prescribed size before proceeding to step F. From the viewpoint of suitability for the manufacturing process, it is preferable to use a highly heat-resistant inorganic substrate for the manufacture of electronic display devices, but when a lightweight and flexible product is required, one possible embodiment is to use a lighter and thinner substrate such as a polymer plate, polymer sheet or FRP plate. Figure 2 shows the case where an adhesive is used instead of a silane coupling agent in steps H to I of Figure 7. When a silane coupling agent is used to bond the second surface of the inorganic substrate to the polymer film, the silane coupling agent layer is extremely thin, so the polymer film is in effect directly supported by the inorganic substrate, which can be considered a rigid body. Therefore, the only elastic layer that supports the wiring layer is the polymer film layer, and the heat, pressure, and ultrasonic vibrations during bonding are not absorbed more than necessary, resulting in bonding with a low defect rate. On the other hand, when an adhesive is used, the elastic layer is made up of two layers, a polymer film and an adhesive layer, and ultrasonic vibration during bonding tends to be easily attenuated. However, in the case of Figure 2, the polymer film of the display element part and the inorganic substrate are bonded on the first surface side of the inorganic substrate with a very thin silane coupling agent layer, so that attenuation of ultrasonic vibration is suppressed for the entire device, and it is possible to ensure a sufficiently high bonding yield rate. However, when an adhesive is used, it is preferable to apply it as thinly as possible and to use an adhesive that exhibits a high elastic modulus as a cured product.

[0040] Figure 3 shows a case where a polymer film is bonded to an inorganic substrate using an adhesive instead of a silane coupling agent in process B. In this case, contrary to Figure 2, the display device as a whole experiences vibration absorption due to the adhesive layer that occupies a wide area. However, since the adhesive layer directly below where bonding is performed is a very thin silane coupling agent layer, it is possible to ensure a sufficiently high rate of bonded products, just like the case of Figure 2. Fig. 4 shows a shape in which the flying lead portion is bent to fit the side of the electronic display device and makes contact with the side. In detail, it becomes the shape of Fig. 13, and the frame width can be narrowed to the lead thickness.

[0041] Next, a process for producing the electronic display device of the present invention using a varnish method will be described with reference to FIGS. Step A in FIG. 8 shows the substrate before processing. Step B in Fig. 8 shows a state in which a polymer solution or polymer precursor solution 35 is applied to the surface of the substrate. The silane coupling agent (layer) is omitted from the figure because it may or may not be used. However, when performing the patterning of adhesive strength described in Japanese Patent No. 5862866, a silane coupling agent is applied to the substrate, and a polymer solution or polymer precursor solution is applied after performing a preliminary treatment for patterning. Step C in FIG. 8 shows a state in which a polymer film is formed on the substrate after drying and, if necessary, chemical reaction. As with the film lamination method, steps A to C correspond to the "(a) step of preparing a laminate having a substrate and a polymer film adhered to at least one side of the substrate" in the varnish method. The subsequent steps are generally similar to those in the film lamination method. In step D of Fig. 8, leads are formed on the polymer film. For convenience, only the peripheral portion is shown. In step E of Figure 8, the electronic display device is formed. The leads are actually connected to a wiring layer that is arranged in a mesh pattern within the electronic display device. Steps D and E correspond to “(b) a step of forming an electronic display device and leads on a polymer film” in the varnish method.

[0042] In step F of FIG. 8, a portion of the substrate is removed. 9 shows the state where the polymer film surrounding the electronic display device is removed by etching or the like from the side opposite to the side with the leads. In this case, the wiring layer also becomes so-called flying leads 42. The method for removing the polymer film is the same as the film lamination method. The steps F and G are "(c) a step of removing the substrate outside the region where the electronic display device is formed, and a step of removing a part of the region where the leads of the polymer film are formed to form a flying lead, thereby forming each region having the following layer structure: Layer structure of area 1 (display area): electronic display device / polymer film / adhesive layer / substrate Layer structure of region 2 (first wiring region adjacent to region 1): lead / polymer film Layer structure of area 3 (flying lead area): Lead The layer structure of the region 4 (second wiring region adjacent to the region 3): corresponds to "lead / polymer film". In the illustration of the process G in FIG. 9, X1: Area 1 (display area) X3: Area 3 (flying lead area) X4: Area 4 (second wiring area adjacent to Area 3 = driver IC mounting area) where X2 is omitted. Here, the method in which X2 is not omitted is explained as the film lamination method, and the method in which X2 is omitted is explained as the varnish method, but this is for convenience of explanation, and whether or not X2 is omitted does not depend on the film lamination method or the varnish method.

[0043] Steps H and I are the same as those in the film lamination method. These steps H and I correspond to the "(d) step of bending region 3 (flying lead region) along the side of the substrate" and the "(e) step of bending and adhering region 4 (second wiring region) along the second surface of the substrate." FIG. 9J shows the state in which a drive circuit element (driver IC) for an electronic display device is mounted. In this manner, similarly to the film lamination method, an electronic display device having a configuration as shown in FIG. 1 can be obtained (however, there is no silane coupling agent layer between the first surface of the substrate and the polymer film layer). As with the film lamination method, in the varnish method, one possible embodiment is to peel off the entire polymer film from the inorganic substrate at the stage of step E, prepare a new substrate of a predetermined size, re-adhere the film, and proceed to step F.

[0044] In the present invention, it is preferable that the outer dimension Lo of the electronic display device and the outer dimension Ld of the display unit of the electronic display device have the following relationship. Lo<(1 / 2)×(Ld+5×Lpx) Here, Lo: External dimensions of electronic display device Ld: External dimensions of the display part of the electronic display device Lpx: the pixel size of an electronic display device. This relationship will be explained with reference to Fig. 10. Fig. 10 shows a cross section near the side surface of an electronic display device. The cutting direction of the cross section is either the X direction or the Y direction of the electronic display device. In the present invention, it is necessary for the above relationship to be established in either the X direction or the Y direction of the display device, or preferably in both directions. The dimension Lov of the area (overhang) outside the display area where images cannot be displayed is half the dimension obtained by subtracting the dimension Ld of the area where images can actually be displayed from the outer dimension Lo of the electronic display device. Lov can be understood as the minimum width of the frame. In the present invention, it is a preferable feature that the overhang width is 2.5 times or less than the pixel dimension. If the frame width is set to about 2.5 times the display pixel or less, the width of the non-display area that occurs when tiling is performed will be about 5 times the pixel size or less, and the tiling seam can be made inconspicuous. It is more preferably 2.4 times or less, even more preferably 2.2 times or less, and particularly preferably 2.0 times or less.

[0045] On the other hand, Lov is the sum of the flying lead thickness Tw and the side gap Lg. The thickness of the flying lead is equal to the thickness of the lead. The flying lead is bent with a finite radius of curvature Ri. In this case, the radius of curvature is equivalent to the sum of Lg and Tw, i.e., it is equal to Lov. Ri=Lg+Tw=Lov The above is a geometric solution for the ideal case in which the polymer film and wiring layer are bent in a perfect arc. In reality, the bent part is distorted into an elliptical arc, so it deviates from the ideal shape. In the present invention, it is preferable to bend the wire so that the bending radius Rr is between 0.7 and 3 times Ri. 0.7×Lov≦Rr≦3×Lov It is preferably 0.8 times or more and 2.5 times or less, more preferably 1 time or more and 2 times or less.

[0046] When the flying lead is bent with a radius of curvature Lov and the substrate thickness Ts is sufficiently thick (Ts>2×Lov), a section Lp can be provided where the substrate side is parallel to the lead polymer film and wiring layer. Lp is calculated as Lp = Ts-2 × Lg This is also a geometric solution for an ideal deformation, and in reality it deviates from the ideal form, but in the present invention, it is preferable that Lp is at least 30% or more of the substrate thickness Ts. That is, Lp ≧ 0.3×Ts It is preferably 40% or more, more preferably 50% or more.

[0047] 12 shows the state when resin is filled into the gaps that occur on the side of the electronic display device of the present invention. By filling the gaps with resin and fixing the shape of the polymer film on the side, the side shape of the electronic display device of the present invention can be maintained well. If a mold or the like is used during fixing, it is possible to make the side shape closer to the ideal shape. Figure 13 shows the state where there is substantially no gap on the side of the electronic display device of the present invention. If the flying lead is made of a plastically deformable metal material, it can be processed into such a shape. In this case, Lov is equal to the thickness of the leaf flying lead, and the frame width can be made very narrow.

[0048] FIG. 14 shows a configuration in which, in addition to the configuration shown in FIG. 13, the substrate and polymer film are removed from the display area of ​​the electronic display device. Since the outer dimension Lo of the electronic display device and the dimension Ld of the display area of ​​the electronic display device are substantially equal, it is possible to eliminate the frame.

[0049] Figure 15 shows a conventional electronic display device using TAB, in which a silane coupling agent is used to bond the polymer film, which is the TAB base material, to the second surface of the substrate. The TAB flying leads and the electronic display device are connected by ACF (anisotropic conductive film). Since the ACF portion cannot be used for display, the width of the ACF is included in the frame, which hinders narrowing the frame.

[0050] Fig. 16 is a detailed schematic cross-sectional view of the side of an electronic display device that has been proposed in the past and is similar to the present invention. The polymer film is bent with a large curvature, which results in a large overhang and makes it difficult to narrow the frame width. This type of shape occurs because the polymer film has poor flexibility, and reducing the curvature increases the possibility of the film being damaged. EXAMPLES

[0051] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. <Laminate Manufacturing A> (Film Lamination Method 1) (Manufacturing of polyimide film APF) After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 223 parts by mass of 5-amino-2-(p-aminophenyl)benzoxazole (DAMBO) and 4416 parts by mass of N,N-dimethylacetamide were added to the reaction vessel and completely dissolved. Next, Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries) in which colloidal silica (average particle size: 0.08 μm) was dispersed in dimethylacetamide was added together with 217 parts by mass of pyromellitic dianhydride (PMDA) so that the colloidal silica was 0.7% by mass relative to the total polymer solid content in the polyamic acid solution A, and the mixture was stirred at a reaction temperature of 25 ° C. for 24 hours to obtain a brown viscous polyamic acid solution Apaa. The obtained polyamic acid solution Apaa was applied onto a mirror-finished endless continuous belt made of stainless steel (coating width 1240 mm) using a die coater, and dried for 10 minutes at 90 to 115° C. The polyamic acid film that became self-supporting after drying was peeled off from the support and both ends were cut to obtain a green film Agf. The obtained green film Agf was conveyed by a pin tenter so that the final pin sheet interval was 1140 mm, and was heat-treated at 170°C for 2 minutes in the first stage, 230°C for 2 minutes in the second stage, and 485°C for 6 minutes in the third stage to promote the imidization reaction. After that, it was cooled to room temperature in 2 minutes, and the poorly flat portions at both ends of the film were cut off with a slitter, and the film was wound up into a roll to obtain a brown polyimide film Apf.

[0052] (Laminate manufacturing using film lamination method 1) One side of the polyimide film Apf was subjected to nitrogen plasma treatment using a vacuum plasma treatment device in a roll-to-roll system, and then cut into a square of 280 mm x 280 mm. An isopropyl alcohol solution containing 1% by mass of a silane coupling agent ("KBE-903" manufactured by Shin-Etsu Chemical Co., Ltd.) was coated onto a 300 mm x 300 mm, 0.5 mm thick glass substrate by spin coating, and then dried at 100°C for 1 minute. Furthermore, to weaken the activity of the silane coupling agent on the periphery of the glass (patterning treatment of adhesive strength), a central 250 mm x 250 mm portion of the glass was masked with a light-shielding plastic sheet, and the entire surface was irradiated with ultraviolet light using a UV / ozone cleaner manufactured by LAN Technical Services. Next, the plasma-treated surface of the film and the silane coupling agent-treated surface of the glass plate were brought into close contact with each other using a vacuum laminator, and heat-treated at 150° C. for 1 minute to obtain a laminate A.

[0053] <Laminate Manufacturing B> (Film Lamination Method 2) (Production of polyimide film Bpf) In a reaction vessel equipped with a nitrogen inlet tube, Dean-Stark apparatus, reflux tube, thermometer, and stirrer, 32.02 parts by mass of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB) and 230 parts by mass of N,N-dimethylacetamide (DMAc) were added and completely dissolved while introducing nitrogen gas, and then 44.42 parts by mass of 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride (6FDA) was added in portions as a solid, and the mixture was stirred at room temperature for 24 hours. After that, a polyamic acid solution Bpaa with a solid content of 25% by mass and a reduced viscosity of 1.10 dl / g was obtained. Next, 204 parts by mass of DMAc was added to the obtained polyamic acid solution Bpaa to dilute the polyamic acid to a concentration of 15% by mass, and then 1.3 parts by mass of isoquinoline was added as an imidization promoter. Next, while stirring the polyamic acid solution, 12.25 parts by mass of acetic anhydride was slowly dropped as an imidization agent. After that, the mixture was stirred for 24 hours to carry out a chemical imidization reaction, and a polyimide solution Bsol was obtained. Next, 100 parts by mass of the resulting polyimide solution Bsol was transferred to a reaction vessel equipped with a stirring device and a stirrer, and 150 parts by mass of methanol was slowly added dropwise while stirring, whereupon precipitation of a powdery solid was confirmed. Thereafter, the powder content of the reaction vessel was dehydrated and filtered, and further washed with methanol, and then vacuum dried at 50° C. for 24 hours, and then heated at 260° C. for an additional 5 hours to obtain polyimide powder Bpd. Polyimide solution B was obtained by dissolving 20 parts by mass of the obtained polyimide powder Bpd in 80 parts by mass of DMAc.

[0054] In an atmosphere conditioned at 25°C and 45% RH, polyimide solution B was applied to the non-slip surface of a polyethylene terephthalate film A4100 (manufactured by Toyobo Co., Ltd., hereinafter abbreviated as PET film) serving as a temporary support, using an apparatus equipped with a roll-to-roll comma coater and a continuous drying oven, so that the final film thickness was 15 μm. Next, the film was heated at 110°C for 10 minutes as primary heating using a continuous dryer, to obtain a semi-dried coating Bgf with a residual solvent content of 25% by mass, which was then wound up into a roll together with the temporary support. The obtained roll was set again in the above-mentioned device, Bgf was unwound together with the temporary support, Bgf was peeled off from the temporary support, passed through a pin tenter having a pin sheet, the film end was held by inserting it into the pin, the pin sheet interval was adjusted so that the film would not break and would not cause unnecessary slack, and the film was conveyed, and the final heating was performed under the conditions of 200° C. for 3 minutes, 250° C. for 3 minutes, and 300° C. for 6 minutes. After that, the film was cooled to room temperature in 2 minutes, and the parts with poor flatness at both ends of the film were cut off with a slitter, and the film was wound up into a roll to obtain a roll of polyimide film Bpf with a width of 530 mm and a length of 80 m. The obtained polyimide film had a thickness of 25 μm, a glass transition temperature of 320° C., a total light transmittance of 92%, a yellow index of 0.8, a tensile modulus of elasticity of 3.4 GPa, a tensile elongation at break of 18%, and a coefficient of thermal expansion (CTE) of 62 ppm / K.

[0055] (Laminate manufacturing using film lamination method 2) The polyimide film Bpf was cut to a size of 280 mm x 280 mm, and was subjected to UV irradiation for 3 minutes using a UV ozone layer value manufactured by LAN Technical Services as a surface activation treatment. A glass substrate of 300 mm x 300 mm and 0.5 mm thickness was exposed to a silane coupling agent ("KBE-903" manufactured by Shin-Etsu Chemical Co., Ltd.) at 40°C or higher for 5 minutes, and then held in dry nitrogen at 60°C for 5 minutes to be treated with the silane coupling agent. Next, the UV-irradiated surface of the film Bpf was joined to the silane coupling agent-treated surface of the glass substrate, and the two were bonded together using a vacuum laminator. Heat treatment was performed at 150°C for 1 minute to obtain a laminate B.

[0056] <Laminate manufacturing C> (Varnish method 1) The polyamic acid solution Apaa obtained during the production of the polyimide film Apf was applied to a glass substrate of 300 mm × 300 mm and 0.5 mm thickness using a bar coater so that the final film thickness would be 20 μm and the effective size would be 280 mm × 280 mm. The applied coating was then dried in a vacuum dryer at 250°C for 30 minutes and then heat-treated in a nitrogen-substituted inert furnace at 450°C for 5 minutes to obtain a laminate C consisting of a polyimide film layer and a glass plate.

[0057] <Laminate manufacturing D> (Varnish method 2) The polyimide solution B obtained in the process of manufacturing the polyimide film Bpf was applied to a glass substrate of 300 mm × 300 mm and 0.5 mm thickness using a bar coater so that the final film thickness would be 18 μm and the effective size would be 280 mm × 280 mm. The applied solution was then heat-treated in a vacuum dryer and a nitrogen-substituted inert furnace at 150°C for 10 minutes, 250°C for 10 minutes, and 300°C for 5 minutes to obtain a laminate D consisting of a polyimide film layer and a glass plate.

[0058] <Manufacturing of simulated devices> Using the obtained laminates A to D, mock display devices were formed on the respective polyimide films. The layout (top view) of the mock display device is shown in FIG. 17. A polyimide film 300 is laminated on a glass substrate 150 by lamination or coating. The leads 400 were formed by metallizing the polyimide film by sputtering nickel-chromium alloy and then sputtering copper to a thickness of 100 nm, followed by electroplating copper to a thickness of 8 μm, processing the lead into a lead shape by an etching method, and further performing electroless tin plating on the lead surface. The mock display device 600 was formed by masking the areas other than the predetermined range after the lead formation, and forming an amorphous silicon thin film to be regarded as a display device. The process up to this point corresponds to process E in FIG. 6 or process E in FIG. 8. Five mock display devices were fabricated using each of the laminates A to D, and the flying leads were formed and molded into mock electronic display devices, as described below.

[0059] Example 1A First, a scribe was made in the glass substrate of the laminate A from the rear surface along the edge of the simulated display device that can be observed through the glass substrate, and then the glass substrate was divided to remove the glass portion that supported the lead portion. This corresponds to step F in Fig. 6 or step F in Fig. 8. Next, the polyimide film was partially removed corresponding to step G of FIG. 7 or step G of FIG. 9 to form flying leads. First, the mock display device was set in a vacuum chamber with a plasma ashing function, and a predetermined portion of the surface of the film portion from which the glass plate had been removed, on which no leads were formed (the surface that had been bonded to the glass), was covered with a stainless steel mask from a position 1.5 mm away from the glass substrate. Then, an ashing process was performed from the glass substrate side using oxygen plasma to remove the portions not covered by the glass substrate and the stainless steel mask: the flying leads and the notches. As a result, a mock display device was obtained that had a shape in which the dimensions corresponding to mock display device X1, shown in step G of FIG. 7 or step G of FIG. 9, were 250 mm, X2 was practically nonexistent, flying lead portion X3 was 1.5 mm, and driver IC mounting portion X4 was approximately 8.5 mm. <Forming into a simulated display device> Next, a forming process equivalent to steps H to J in Figure 7 or Figure 9 was carried out. That is, the flying lead portion was first bent along the side of the glass plate, and then bent again along the back surface of the glass plate. A silane coupling agent was applied beforehand to the back surface of the glass plate in the area where the polyimide film located on the outside of the flying leads would come into contact, and after the polyimide film was tightly attached and stacked, it was fixed together with a backing plate with clips and heated to 100°C for 5 minutes to bond the polyimide film to the back surface of the glass. This area corresponds to the area where the driver IC will be mounted. <Examples 1B, 1C, and 1D> The same processing was carried out using laminates B to D. These are designated as Examples 1B, 1C, and 1D, respectively. In all cases, including Example 1A, no damage to the flying leads was observed, and no particular problems occurred during the molding process.

[0060] Example 2A Instead of carrying out plasma ashing in Example 1, sandblasting was carried out. Before being set in the sandblasting machine, the entire surface on which the simulated display device was formed was masked with a 50 μm-thick photosensitive, alkali-peelable dry film resist laminate. The opposite side was also similarly laminated with dry film resist, and the parts to be made into flying leads and the parts to be cutouts were covered with a light-shielding mask and exposed to ultraviolet light, and then the dry film resist was developed. Next, the laminate after the dry film masking treatment was placed in a wet blasting device manufactured by Maco Corporation, and unnecessary portions of the polyimide film were removed by wet blasting treatment using alumina abrasive particles with an average particle size of 5 μm. The dry film resist was then subjected to an alkaline stripping treatment to obtain a pre-molding mock device with flying leads. Thereafter, molding was carried out in the same manner as in Example 1A, and the flying lead portion was observed and the processability was evaluated. <Examples 2B, 2C, and 2D> The same processing was carried out using laminates B to D. These are designated as Examples 2B, 2C, and 2D, respectively. In all cases, including Example 2A, no damage to the flying leads was observed, and no particular problems were found during the molding process.

[0061] Example 3A The masking in Example 2 was an aluminum vapor deposition film with a thickness of 0.8 μm. Next, the laminate after the masking process was set in a stainless steel processing tank with a stirrer, and an etching process was performed at 70° C. for 10 minutes using a polyimide chemical etching solution TPE3000 manufactured by Raytec Corporation to form flying leads, and then the aluminum vapor deposition film used as the mask was removed by etching in an aqueous hydrochloric acid solution. Note that TPE300 is an aqueous solution of an alkaline compound and is strongly alkaline. Thereafter, molding was carried out in the same manner as in Example 1A, and the flying lead portion was observed and the processability was evaluated. <Example 3B, 3C, 3D> The same processing was carried out using laminates B to D. These are designated as Examples 3B, 3C, and 3D, respectively. In all cases, including Example 3A, no damage to the flying leads was observed, and no particular problems were found during the molding processing.

[0062] Example 4A The process was carried out in the same manner as in Example 1A up to the removal of the unnecessary glass portions. No masking was used, and the unnecessary portions were cut off directly from the glass surface side of the laminate after the formation of the mock display device using a YAG laser. As for the flying lead portions, the polyimide film portions were removed by ablation through intermittent irradiation of laser light to form flying leads. <Examples 4B, 4C, and 4D> The same processing was carried out using laminates B to D. These are designated as Examples 4B, 4C, and 43D, respectively. In all cases, including Example 3A, no damage to the flying leads was observed, and no particular problems were found during the molding processing.

[0063] (Preparation of polyamic acid solution (PAA1) and polyamic acid solution containing lubricant (V1)) The nitrogen inlet tube, thermometer, stirring rod, and infusion piping of the reaction vessel, which is made of austenitic stainless steel SUS316L, were replaced with nitrogen, and 223 parts by mass of 5-amino-2-(p-aminophenyl)benzoxazole (DAMBO) was added. Next, 4000 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 420 parts by mass and 217 parts by mass of pyromellitic dianhydride (PMDA) were added to the preliminary dispersion obtained above, and the mixture was stirred at 25°C for 48 hours to obtain a brown viscous polyamic acid solution (PAA1). The reduced viscosity (ηsp / C) was 5.5 dl / g. To the obtained polyamic acid solution (PAA1), a dispersion of colloidal silica dispersed in dimethylacetamide (Nissan Chemical Industries, Ltd.'s "Snowtex (registered trademark) DMAC-ST-ZL") was added as a lubricant so that the silica (lubricant) accounted for 0.5 mass% of the total polymer solid content in the polyamic acid solution, thereby obtaining a lubricated polyamic acid solution (V1).

[0064] The reduced viscosity of the polyamic acid was measured by the following method. <Reduced viscosity of polyamic acid (ηsp / C)> A solution of a polymer (polyamic acid) dissolved in N-methyl-2-pyrrolidone so as to give a polymer (polyamic acid) concentration of 0.2 g / dl was measured at 30° C. using an Ubbelohde type viscometer.

[0065] (Preparation of polyamic acid solution (PAA2) and polyamic acid solution containing lubricant (V2)) The nitrogen inlet tube, thermometer, stirring rod, and infusion piping of the reaction vessel made of austenitic stainless steel SUS316L were replaced with nitrogen, and 108 parts by mass of phenylenediamine (PDA) was added. Next, 3600 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 420 parts by mass and 292.5 parts by mass of diphenyltetracarboxylic dianhydride (BPDA) were added to the preliminary dispersion obtained above, and the mixture was stirred at 25°C for 12 hours to obtain a brown viscous polyamic acid solution (PAA2). The reduced viscosity (ηsp / C) was 4.5 dl / g. Colloidal silica was added in the same manner as in the preparation of polyamic acid solution (V1), and a lubricant-containing polyamic acid solution (V2) was obtained.

[0066] (Preparation of polyamic acid solution (PAA3) and polyamic acid solution containing lubricant (V3)) The liquid-contacting parts of the vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod, and the infusion piping were made of austenitic stainless steel SUS316L, and the inside of the reaction vessel was replaced with nitrogen, and 200 parts by mass of diaminodiphenyl ether (ODA) was added. Next, 3800 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 390 parts by mass and 217 parts by mass of pyromellitic dianhydride (PMDA) were added to the preliminary dispersion obtained above, and the mixture was stirred at 25°C for 5 hours, resulting in a brown viscous polyamic acid solution (PAA3). The reduced viscosity (ηsp / C) was 3.7 dl / g. Colloidal silica was added in the same manner to obtain a polyamic acid solution containing a lubricant (V3).

[0067] [Preparation of polyamic acid solution (PAA4) and polyamic acid solution containing lubricant (V4)] After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 1765 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 310 parts by mass of 4,4'-oxydiphthalic acid (ODPA), 1601 parts by mass of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB), 1136 parts by mass of 4-amino-N-(4-aminophenyl)benzamide (DABAN), and 20000 parts by mass of N,N-dimethylacetamide were charged and dissolved in the reaction vessel under a nitrogen atmosphere, and then stirred at room temperature for 24 hours. After that, the mixture was diluted with an appropriate amount of N,N-dimethylacetamide to obtain a polyamic acid solution (PAA4) with a reduced viscosity of 4.50 dl / g. Colloidal silica was added in the same manner to obtain a polyamic acid solution (V4) containing a lubricant.

[0068] [Preparation of polyimide solution (PI5) and polyimide solution containing lubricant (V5)] After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 4610 parts by mass of N,N-dimethylacetamide (DMAC) and 640 parts by mass of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB) were added to the reaction vessel under a nitrogen atmosphere and stirred to dissolve TFMB in DMAC. Next, while stirring the inside of the reaction vessel, 897.37 parts by mass of 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride (6FDA) was added over about 10 minutes under a nitrogen stream, and the polymerization reaction was carried out by continuing stirring for 6 hours while adjusting the temperature to be in the range of 20 to 40 ° C., to obtain a viscous polyamic acid solution (PAA5). Next, 4100 parts by mass of DMAC was added to the obtained polyamic acid solution (PAA5) to dilute it, and then 258.3 parts by mass of isoquinoline was added as an imidization accelerator. The polyamic acid solution was kept at a temperature range of 30 to 40°C while stirring, and 1225 parts by mass of acetic anhydride was slowly added dropwise as an imidization agent over a period of about 10 minutes. The liquid temperature was then further kept at 30 to 40°C and stirring was continued for 12 hours to carry out a chemical imidization reaction, thereby obtaining a polyimide solution (PI5a).

[0069] Next, 10,000 parts by mass of the polyimide solution (PI5a) containing the obtained imidization agent and imidization accelerator was transferred to a reaction vessel equipped with a stirrer and agitator, and the temperature was kept at 15 to 25 ° C while stirring at a speed of 120 rpm, and 15,000 parts by mass of methanol was dropped therein at a rate of 10 g / min. When about 8,000 parts by mass of methanol was added, the polyimide solution became turbid and precipitation of powder-like polyimide resin was confirmed. Subsequently, the entire amount of 15,000 parts by mass of methanol was added, and precipitation of polyimide resin was completed. Next, the contents of the reaction vessel were filtered with a suction filtration device, and further washed and filtered with 10,000 parts by mass of methanol to obtain a polyimide resin powder. The obtained polyimide resin powder was dried at 50 ° C for 24 hours using a dryer equipped with a local exhaust device, and further dried at 260 ° C for 2 hours to remove the remaining volatile components, and a dry polyimide powder was obtained. The reduced viscosity of the obtained dry polyimide powder was 5.40 dl / g. Next, 400 parts by mass of the obtained dry polyimide powder was dissolved in 3000 parts by mass of DMAc to obtain a polyimide solution (PI5). Colloidal silica was then added in the same manner to obtain a polyimide solution containing a lubricant (V5). The resulting polyamic acid solutions or polyimide solutions, and solutions containing lubricants, are listed in Tables 1 and 2.

[0070] [Table 1]

[0071] [Table 2]

[0072] [Film manufacturing example] The lubricant-containing polyamic acid solution (V1) was pumped and coated onto a polyethylene terephthalate film support to a final thickness of 38 μm, and then dried for 30 minutes at 110° C. The polyamic acid film, which had become self-supporting after drying, was peeled off from the support to obtain a polyamic acid film (green film). The obtained green film was passed through a continuous heat treatment furnace and heated in two stages, with the first stage at 200°C for 3 minutes, the temperature increased at a rate of 4°C / sec, and the second stage at 480°C for 5 minutes, to allow the imidization reaction to proceed. It was then cooled to room temperature in 5 minutes, and both ends (edges) were slit to obtain a polyimide film F1 with a width of 524 mm, a length of approximately 200 m, and a thickness of 38 μm at the center only.

[0073] Similarly, polyimide film F2 was obtained from polyamic acid solution V2, polyimide film F3 from polyamic acid solution V3, polyimide film F4 from polyamic acid solution V4, and polyimide film F5 from polyamic acid solution V5 by appropriately adjusting the coating thickness and heat treatment conditions. The properties of the obtained polyimide films are shown in Table 3. The values ​​in the table are the average values ​​in the MD and TD directions. MD is the longitudinal direction when the film is formed, and TD is the transverse direction when the film is formed.

[0074] [Table 3]

[0075] [Polyimide film / glass substrate laminate] <Vacuum plasma treatment of polyimide film> The polyimide film F1 was subjected to vacuum plasma treatment. The vacuum plasma treatment was performed using a device for treating long films, and the inside of the vacuum chamber was heated to 1×10 -3 The vacuum chamber was evacuated to a pressure of less than 1 Pa, and argon gas was introduced into the vacuum chamber, followed by argon gas plasma treatment for 20 seconds under conditions of a discharge power of 100 W and a frequency of 15 kHz.

[0076] <Silane coupling agent treatment of glass substrate> The glass substrate [G] was OM10G manufactured by Nippon Electric Glass Co., Ltd., measuring 470 mm x 370 mm and 0.7 mm thick. After replacing the atmosphere in a chamber equipped with a hot plate and a support stand for an inorganic substrate with clean dry nitrogen, the glass substrate that had been subjected to UV / ozone treatment was placed on the support stand, and a petri dish filled with a silane coupling agent (3-aminopropyltrimethoxysilane) was placed so that the liquid level was located 200 mm below the glass substrate. The petri dish was heated to 100°C on a hot plate, and the bottom surface of the glass substrate was exposed to the silane coupling agent vapor for 3 minutes. After that, the petri dish was removed from the chamber and placed in a clean bench. The glass substrate was placed on a hot plate adjusted to 120°C so that the opposite side of the exposed surface of the glass substrate was in contact with the hot plate, and heat treatment was performed for 1 minute to perform silane coupling agent treatment.

[0077] <Lamination> The plasma-treated surface of the polyimide film was placed on the silane coupling agent-treated surface of the glass substrate, and the polyimide film was temporarily pressed with a roll laminator. The polyimide film was then placed in a clean bench and placed on a hot plate adjusted to 150°C with the inorganic substrate side in contact with the hot plate, and heat-treated for 3 minutes to obtain a polyimide film / glass substrate laminate (LF1). The polyimide / glass substrate laminate was stored in an environment with a temperature of 20 to 25°C and a relative humidity of 65±30%. Similarly, a polyimide film / glass substrate laminate (LF2) was obtained from film F2 and a glass substrate. Further, polyimide film / glass substrate laminates (LF3), (LF4), and (LF5) were obtained from films F3, F4, and F5 and a glass substrate in the same manner.

[0078] <Example 5> Using the obtained polyimide film / glass substrate laminate, a display panel was fabricated in a simulated manner by the process shown in Fig. 6 and Fig. 7. For convenience, this process is called the film method. The glass substrate corresponds to step A in Fig. 6, the glass substrate treated with a silane coupling agent corresponds to step B, and the polyimide film / glass laminate corresponds to step C. The wiring layer 40 was formed by forming a nickel-chromium alloy layer by a sputtering method, forming a copper thin film by a sputtering method, and then thickening the copper by electroplating, and etching a resist to remove unnecessary portions, by patterning using a so-called subtractive method.

[0079] As the electronic display device layer 60, an electrophoretic element driven by a TFT using an amorphous silicon thin film as a semiconductor was formed, the glass substrate was cut with a laser cutter to remove unnecessary parts, and in step G of Fig. 7, the film part was removed with a laser processing machine to make the corresponding part into a flying lead, and the flying lead part was bent so as to follow the side of the glass substrate and folded to the back side of the glass substrate. As the silane coupling agent solution 21, a 1 mass % methanol solution of 3-aminopropyltrimethoxysilane was used, dropped at a predetermined position with a dispenser (for convenience, the display device layer is illustrated as the upper surface, but in reality, the operation is performed upside down after this step), and the polyimide film that was dried and then folded was pressed against the back side of the glass substrate and heated to complete the adhesion in accordance with the production of a polyimide film / glass substrate laminate, and finally a driver IC was mounted to obtain a simulated panel (PF1). In the same way, multiple (PF1) panels were created, arranged in tiles to make a larger surface area, and image signals were sent to check the display. There were no particular pixel defects between the simulated panels, and it was confirmed that good quality images were displayed.

[0080] <Examples 6 to 9> Thereafter, the polyimide film glass laminates (LF2), (LF3), (LF4), and (LF5) were used to obtain simulated panels (PF2), (PF3), (PF4), and (PF5) in the same manner. There were no abnormalities in the flying leads of any of the panels, and good image display results were obtained over a large area by tiling.

[0081] <Example 10> Next, an example using the varnish method is shown. Step A in Figure 8 is a glass substrate. Step B is when a polyamic acid solution (PAA1) is applied to a glass substrate to a specified thickness, and step C is when a polyimide layer is formed by drying and then heating in an inert oven, i.e., a polyimide layer / glass substrate laminate (LS1) is obtained. (In the varnish method, the polyimide film portion is sometimes called the polyimide layer to distinguish it from the film method.) After that, the same operation as in the film method is carried out, and the process shown in Figure 9 is carried out. In step G, a portion of the polyimide layer is removed using a laser processing machine to make the wiring part into a flying lead, and the flying lead portion is bent along the side of the glass substrate, and the same operation is carried out to produce a simulated panel (PS1). There was no abnormality in the flying lead portion, and this was also tiled in the same way as in the film method, and the display image quality was observed, confirming that good image quality was obtained.

[0082] <Examples 11 to 13> Similarly, simulated panels (PS2), (PS3), and (PS4) were obtained from polyamic acid solutions (PAA2), (PAA3), and (PAA4). None of the panels had any abnormalities in the flying lead area, and good image display results were obtained by tiling. [Industrial Applicability]

[0083] As described above, the electronic display device of the present invention can have a narrow frame, has a low defect rate for driver IC mounting, and is preferably applicable to self-emissive elements and reflective elements, resulting in a display device suitable for tiling applications. The present invention will make a significant contribution to the industrial world, particularly as a technology for economically manufacturing large-area display devices. [Explanation of symbols]

[0084] 1:Electronic display 15: Circuit board 20: Silane coupling agent condensation product layer 21: Silane coupling agent (solution) 30: Polymer film 32: Etching section 35: Polymer solution or polymer precursor solution 40: Lead (wiring layer) 42: Flying lead section 50: Driver circuit elements for electronic display devices (driver ICs) 60: Electronic display devices 70: Adhesive layer 80: Anisotropic conductive film (ACF) 90: Casting resin 150: Glass substrate 300: Polyimide film 310: Cutout area of ​​polyimide film 400: Lead 600: Simulated display device X1: Area 1 (display area) X2: Area 2 (first wiring area adjacent to Area 1) X3: Area 3 (flying lead area) X4: Area 4 (second wiring area adjacent to area 3) Lo: External dimensions of electronic display device Ld: External dimensions of the display part of the electronic display device Lg: Side gap Lp: Parallel side dimension Lpx: the pixel size of an electronic display device Lov: Overhang dimension (Lg+Lb) Ts: substrate thickness Tf: Polymer film thickness Tw: Lead thickness (flying lead thickness)

Claims

1. 1. An electronic display device, comprising: substrate, a first polymeric film adhered to a first surface of the substrate; an electronic display device formed on the first polymeric film; leads for supplying power and drive signals to said electronic display device; a second polymeric film adhered to a second surface of the substrate; drive circuitry mounted on said second polymeric film for driving said electronic display device; Including, An electronic display device, wherein a portion of the lead between a side surface of the electronic display device and a drive circuit element is a flying lead.

2. 2. The electronic display device according to claim 1, wherein a portion of the flying leads is arranged parallel to a side surface of the substrate, and the length of the parallel section is 30% or more of the thickness of the substrate.

3. 3. The electronic display device according to claim 1, wherein a part or all of the flying leads are in contact with a side surface of the substrate.

4. 4. The electronic display device according to claim 1, wherein the second polymer film and a part or the whole of the second surface of the inorganic substrate are bonded to each other via a silane coupling agent condensate layer.

5. 5. The electronic display device according to claim 1, wherein the first polymer film and the first surface of the inorganic substrate are partly or entirely bonded to each other via a silane coupling agent condensate layer.

6. (a) providing a laminate having a substrate and a polymeric film adhered to at least one side of the substrate; (b) forming an electronic display device and leads on the polymeric film; (c) removing the substrate outside the area in which the electronic display device is formed; and removing a part of the polymer film in the area where the leads are formed to form flying leads. A process of forming each region having the following layer configuration through the steps of: Layer structure of region 1 (display region): electronic display device / polymer film / adhesive layer / substrate Layer structure of region 2 (first wiring region adjacent to region 1): lead / polymer film Layer structure of area 3 (flying lead area): Lead Layer structure of region 4 (second wiring region adjacent to region 3): lead / polymer film (d) bending region 3 (flying lead region) along the side of the substrate; (e) bending region 4 (second wiring region) along the second surface of the substrate and adhering it to the second surface of the substrate; A method for manufacturing an electronic display device having at least the above-mentioned features.

7. 7. The method for manufacturing an electronic display device according to claim 6, wherein the step of removing a portion of the polymer film is performed by a plasma etching method.

8. 7. The method for manufacturing an electronic display device according to claim 6, wherein the step of removing a portion of the polymer film is a sandblasting method.

9. 7. The method for manufacturing an electronic display device according to claim 6, wherein the step of removing a portion of the polymer film is performed by mechanical grinding.

10. 7. The method for manufacturing an electronic display device according to claim 6, wherein the step of removing a portion of the polymer film is an etching method using a solution of an alkaline compound.

11. 11. The method for manufacturing an electronic display device according to claim 6, wherein the region 2 is omitted and the regions 1 and 3 are directly adjacent to each other.

Images