JPS62102322A - Manufacture of transparent resistance sheet with anisotropic conductive layer - Google Patents

Abstract

PURPOSE:To eliminate damage to a resistance film by using a transparent resistance sheet which has an anisotropic conductive layer. CONSTITUTION:When the transparent sheet 5 which has the transparent resistance film 2 formed of ITO (oxide indium or tin oxide) on a transparent glass plate 1 is manufactured, mixed liquid consisting of a stock solution of resin and numbers of magnetic conductive short fibers 4 is charged between the sheet 5 and its cover film 6 and the short fibers 4 are oriented in the thickness direction of the film 6 through the operation of a magnetic field. Further, the liquid thickness is set a little bit larger than the short fiber length and short fibers 4 which contact the cover film 6 and short fibers 4 which contact the resistance film 2 are produced alternately through magnetic operation between the fibers. Further, the cover film 6 is removed after the matrix resin sets and polishing is carried out until the short fibers 4 contacting the resistance film 2 are exposed, thus obtaining the transparent resistance film 5 which has the anisotropic conductive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) Used as a material for an image information input device in information-related equipment. A warp roller computer or a device in which a transparent input device made using a transparent resistive sheet having an anisotropic conductive layer according to the method of the present invention is overlapped with a planar display so that input and output are performed on the same surface Used as a video phone terminal.

(Prior art) A plurality of electrodes are provided around a sheet with appropriate sheet resistance, electricity is injected from one point in the sheet, and the coordinate data of the injection point is obtained by detecting the amount of electricity flowing into each electrode. It is known that it is possible to input. If the sheet is transparent, such as Nesa glass, it can be stacked with a panel display such as a Dotmarix liquid crystal display so that input and output can be performed on the same surface, and it can be used as a terminal for a word processor, computer, or video telephone. Can be used.

(Problems to be Solved by the Invention) Generally, a transparent resistive film is a very thin film made of metal or metal oxide. Therefore, when an input pen is run directly over this resistive film, it often causes scratches on the resistive film, impairing the accurate position detection function. The present invention relates to an improved method for manufacturing a transparent resistive sheet that retains the pen-based input function while preventing damage to the resistive film caused by the pen.

(Means for solving problems) In order to achieve the above object, the present invention consists of the following configuration.

"A liquid mixture consisting of a transparent cured physical resin stock solution and a large number of magnetic conductive short fibers is held in the space formed between the resistive film surface of the transparent resistance sheet and the cover sheet, and a magnetic field is applied to make the magnetic conductive short fibers. A method for producing a transparent resistive sheet having an anisotropic conductive layer, characterized by orienting fibers in the thickness direction of the sheet and curing a resin stock solution while maintaining that orientation.'' Figure 1 shows the anisotropic conductive layer of the present invention. FIG. 2 is a partial cross-sectional view showing an example of a method for manufacturing a transparent resistive sheet having a conductive layer.

ITO (indium chloride,
A mixed solution consisting of a resin stock solution 3 and a large number of magnetic conductive short fibers 4 is filled between a transparent resistive sheet 5 on which a transparent resistive film 2 of tin oxide (tin oxide) is formed and a cover sheet 6. Due to this action, the short fibers are already oriented in the thickness direction of the sheet. As shown in this example, by setting the liquid thickness slightly larger than the length of the short fibers, the orientation of the short fibers becomes perfect. Fibers and short fibers in contact with the resistive film occur almost alternately. After the matrix resin has hardened, the cover film is removed and, if necessary, the transparent resistive sheet having the desired anisotropic conductive layer can be replaced by grinding to the dotted line, that is, until the short fibers in contact with the resistive film are exposed. This is shown in Figure 2. If the length of the short fibers is equal to or larger than the thickness of the matrix layer, and most of the short fibers are in contact with both the resistive film and the cover film from the beginning, then only slight grinding is required; Or it's unnecessary.

Before curing the resin, press slowly until the liquid thickness becomes smaller than the length of the short fibers, and then cure, to obtain a product in which all the short fibers are in contact with the resistive film as shown in Figure 3. I can do it. In this case, the short fibers may be twisted, resulting in a slight decrease in optical quality. The machine is a bit complicated in terms of equipment (yellow or yellow is required).

At least the side of the cover film in contact with the resin stock solution is formed of a soft material so that when the short fibers are pressed slowly until the liquid thickness becomes smaller than the length of the short fibers, the short fibers invaginate into the cover film without bending. Then, as mentioned above, before curing the resin, press slowly until the liquid thickness becomes smaller than the short fiber length, and then cure the resin.
As shown in the figure, it is possible to obtain a product in which all the short fibers are in contact with the resistive film and maintain linearity. In this case, the transparent resistive sheet having the desired anisotropic conductive layer can be replaced by only slight polishing.

It is also possible to orient the short fibers after setting the liquid thickness to be smaller than the length of the short fibers from the beginning. In this case as well, as shown in Figure 5, it is possible to make 1q with all the short fibers in contact with the resistive film and maintaining their linearity, but the perpendicularity of the short fibers is disturbed, resulting in poor optical and electrical performance. It will decrease slightly.

The transparent resistance sheet used for this purpose is obtained by forming a thin film of a conductive metal or metal oxide on a transparent glass or plastic film by vapor deposition, sputtering, or other known techniques. A typical example is a thin film formed by adding a small amount of indium oxide to tin oxide on glass. The resistance value of the thin film is not particularly limited, but for input devices it is 50~
A material having a resistance of 1000 ohms/Sq is preferably used.

Further, it is preferable that the visible light transmittance of the transparent resistance sheet is 40% or more. In order to improve the adhesion of the resistive sheet, the surface of the resistive film is sometimes subjected to surface treatment such as organic titanate, vinyl silane, alkali, acid, or low-temperature plasma treatment.

The material forming the matrix of the transparent anisotropic conductive layer may be any material that is fluid in the raw material stage and forms a hard and transparent matrix by chemical hardening, cooling solidification, or the like.

The hardness after curing is preferably B or higher on a pencil hardness scale,
Those of H or higher are particularly preferred. It is preferable that the electrical insulation property after curing be high, but it does not necessarily have to be a perfect insulator, and in terms of sheet resistance value, it is sufficient if it is 100 times or more that of the transparent resistive film, and usually it is 1 megaohm/Sq or more. Bye.

Various compositions are used, including epoxy, acrylic, copolymerized polyester, and low-melting glass, including organic, inorganic, reaction-curing, and thermoplastic materials, but epoxy-based materials are particularly excellent. The final thickness of the matrix layer is preferably 1 mm or less, and a range of 0.1 mm to Q5 mm is particularly preferably used.

The conductive short fibers used for this are nickel, Kobal 1~
, iron, and various magnetic metals or magnetic alloys, including stainless steel. Alternatively, composite materials of these metals and non-magnetic materials may be used. Examples of this type of material include glass fibers or carbon fibers whose surfaces are plated with nickel. Gold, silver, copper,
It can also be coated with other metals such as tin. The diameter of the short fibers is Q, which is extremely thin, 1 mm or less, more preferably 0.03 mm or less. The density of the short fibers is preferably 10 or more fibers per square mm that are completely penetrated.

The cover sheet may be in the form of a film, sheet, or plate, but it is necessary to select one that does not shrink or deform significantly during the curing process of the matrix material. If the surface is subjected to release treatment with silicone, fluorocarbon polymer, etc., it can be easily removed. A polyester film whose surface has been treated with silicone is particularly preferably used. However, the cover sheet can be removed not only by peeling but also by mechanical grinding, or it can be made of an easily soluble material and removed by dissolving it with a solvent.

The anisotropic conductive layer is made by casting a liquid 71-Rix stock solution containing conductive short fibers on the resistive film surface of the transparent resistive sheet.
After covering the surface with the same material, due to the action of the magnetic field,
It is formed by orienting the short fibers in a direction perpendicular to the plane, curing or solidifying the matrix while maintaining that orientation, then removing the cover and polishing or grinding the surface as necessary. Instead of casting, it is of course possible to inject a liquid stock solution of 71-Rix, which is a mixture of conductive short fibers, into the gap surrounded by the resistive film surface of the transparent resistive sheet and the cover sheet surface.

The transparency of the composite thus obtained as a whole is preferably 30% or more in terms of visible light transmittance.

Further, it is preferable that the haze value determined by the following formula is 80% or less.

Haze value (%) = (diffuse light transmittance/total light transmittance) [Example] Moro-butoxy-bis (acetylacetate 1- 1~) A 1% MEK solution of titanium was applied thinly and dried at 120'C for 3 minutes.

90 parts of Epicor 1-827.10 parts of Epicor 1-1
A diameter of 12 microns, an average length of 0.33 mm, and a standard deviation of length of 0.01 were added to an epoxy stock solution consisting of 54.50 parts of Epome 1 to BOO2W (all products of Yuka Shell Co., Ltd.).
5 parts of magnetic stainless steel short fibers of 0.4 mm thick were added to the transparent resistive sheet prepared earlier, with a picture frame-shaped spacer of 4 mm thick placed around it, to a thickness of 0.4 mm. It was covered with a polyimide film that had been cast and subjected to mold release treatment. Heat at 60°C for 11 hours while applying a magnetic field perpendicular to the surface to orient the short fibers in the thickness direction until the epoxy is almost cured, then heat at 60°C for 12 hours without applying a magnetic field. and completely cured. The cover film was removed, and the epoxy layer was ground to a thickness of 0.30 mm and further polished to a mirror finish. It was observed that the jqed composite was substantially transparent and exactly half of the embedded short fibers were in contact with the ITO membrane. The resistance value between any two points measured through the transparent anisotropic conductive layer using the conductive rubber as an electrode was almost the same as the value of the raw material conductive plate glass, and it was confirmed that the resistance could be input to the resistive film through the short fibers.

[Effects of the Invention] By using the transparent resistive sheet having an anisotropic conductive layer obtained by the present invention, it is possible to obtain a transparent input device in which the resistive film is not damaged even when input is directly made with a power injection pen. I can do it.

[Brief explanation of drawings]

Figure 1 shows an example of the transparent conductive composite manufacturing process according to the present invention.
5a is a partial cross-sectional view. FIG. 2 is a partial cross-sectional view of an embodiment of a transparent resistive sheet having a 1q anisotropic conductive layer according to the present invention. 3, 4, and 5 are partial cross-sectional views of other embodiments of the transparent conductive composite manufacturing process according to the present invention. 1
Transparent temporary glass 2; Transparent resistive thin film 3 formed on plate glass; Transparent matrix layer 4; Transparent resistive sheet 6 made of conductive short fibers 5:1 and 2; Cover film

Claims (6)

[Claims] (1) A liquid mixture consisting of a transparent cured physical resin stock solution and a large number of short magnetic conductive fibers is held in the space formed by the resistive film surface of the transparent resistive sheet and the cover sheet, and a magnetic field is applied to conduct the magnetic conductive material. 1. A method for producing a transparent resistance sheet having an anisotropic conductive layer, which comprises orienting short fibers in the thickness direction of the sheet and curing a resin stock solution while maintaining this orientation. (2) Production of a transparent resistance sheet having an anisotropic conductive layer according to claim (1), which comprises curing the resin stock solution, removing the cover sheet, and grinding the cured resin surface. Method. (3) The base material of the transparent resistance sheet is glass or plastic film,
1) A method for producing a transparent resistive sheet having an anisotropic conductive layer as described in item 1). (4) The method for manufacturing a transparent resistive sheet having an anisotropic conductive layer according to claim (1), wherein the electrically resistive film of the transparent resistive sheet is made of a metal or a metal oxide. (5) Claim (4), characterized in that the metal or metal oxide consists of indium oxide and tin oxide.
A method for manufacturing a transparent resistive sheet having an anisotropic conductive layer as described in 1. (6) The method for manufacturing a transparent resistance sheet having an anisotropic conductive layer according to claim (1), wherein the conductive short fibers are magnetic metal fibers.