JPH04112421A - Touch panel - Google Patents

Abstract

PURPOSE:To accomplish a touch panel with which the dimensional accuracy is enhanced and poor workmanship of appearance can be reduced, by forming a rectangular electrode over the surface of a highpolymer film in such an arrangement that the longer sides of rectangle are directed longitudinally, and thereby decreasing thermal contraction. CONSTITUTION:A touch panel 9 is formed by lamination of highpolymer film 1 on an insulated base board 7 with an insulative spacer 8 interposed, wherein the insulated base board 7 consists of glass plate or acrylic plate, and a rectangular electrode 10 is provided perpendicularly intersecting an electrode 2 furnished on the highpolymer film 1. Formation of rectangular electrode with the longer sides directed longitudinally alongside the highpolymer film in this manner allows preventing the film from contracting in the longitudinal direction even in case heating is made at a high temp. when a drawout circuit is to be formed by using electroconductive ink of thermo-hardening type.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a touch panel.

(Prior Art) Conventionally, a touch panel is installed on the surface of a display such as a CRT display or a liquid crystal display, and is used as an information input device or a coordinate indicating device.

This touch panel has a structure in which, for example, an insulating substrate in which electrodes are formed on a glass plate, an acrylic plate, etc., and an insulating substrate in which electrodes are formed in a flexible polymer film are laminated.

To manufacture this touch panel, first, ITO or the like is deposited on one entire surface of a polymer film.

After vapor deposition, the polymer film is cut to a predetermined width and length to form rectangular cut pieces. After cutting, the vapor deposited layer of ITO or the like is etched to form a plurality of rectangular south poles in parallel with the long sides aligned in the width direction of the polymer film. After forming the electrodes, a conductive ink is printed to form a zero circuit for forming an extraction circuit, and then the entire polymer film is punched out with a die into a predetermined shape.

As a polymer film, if it is thin, it will loosen, and when pressed, the repulsive force will be small and the feeling of pressing will be poor.
To solve this problem, materials with a thickness of 100 μm or more have come to be used.

In addition, conductive ink is generally a heat-drying type that is stable at a temperature of 70 to 80°C and can form lead-out circuits with high precision dimensions, but if the polymer film is thick, In order to improve bending resistance, it is preferable to use a thermosetting type.

(Problem to be solved by the invention) However, when thermosetting conductive ink is used, it is necessary to heat it to a temperature of 130°C or higher after printing, and in that case,
Polymer film tends to shrink in the direction perpendicular to the width direction (hereinafter referred to as the longitudinal direction), and the heat shrinkage is different between the part where the electrode is formed and the other part, and the latter shrinks more easily, causing a wavy shape. It also rises, reducing dimensional accuracy.
It also has the disadvantage of poor appearance.

An object of the present invention is to provide a touch panel that improves the above-mentioned drawbacks, improves dimensional accuracy, and has a good appearance.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a touch panel in which at least one side is a polymer film and an insulating substrate is laminated with an electrode on the surface. The present invention provides a touch panel characterized by providing rectangular electrodes with long sides aligned in the direction.

(Function) If a rectangular electrode is formed with its long side aligned with the longitudinal direction of the polymer film, it will be more stable even when heated at high temperatures when forming an extraction circuit using thermosetting conductive ink. , the resistance force of the electrodes can prevent the polymer film from shrinking in the longitudinal direction.

(Example) Hereinafter, the present invention will be explained based on examples.

In FIG. 1, 1 is a polymer film such as polyester. 2 is an I provided on the surface of this polymer film 1.
It is an electrode made of a transparent conductive film such as TO, and has a rectangular shape.
A plurality of strips are formed in parallel, with their long sides 3 aligned with the longitudinal direction 4 of the polymer film 1. 5 is a lead-out circuit formed from the electrode 2 to the tail portion 6, which is the protruding portion of the polymer film 1, and is a thermosetting circuit made by dispersing substances such as Ag, Ni, Cu, and carbon in a polyester or epoxy binder. It is formed by printing conductive ink. To form t[i2 on the polymer film 1, first, the polymer film is run in a wide state in a vacuum chamber, ITO, etc. is sputtered in the vacuum chamber, and a transparent conductive film is layered on the entire surface of one side. The primary polymer film forming 1/2
Cut it to a width of 1, and then cut it to an appropriate length in the longitudinal direction to form a rectangular shape. After cutting, the transparent conductive film is etched to form a plurality of parallel rectangular electrodes 2 with their long sides aligned in the longitudinal direction of the polymer film. After forming the electrode 2, a thermosetting conductive ink is printed and heated to a high temperature to form an extraction circuit.

Then, the polymer film 1 shown in FIG.
As shown in the figure, a touch panel 9 is formed by laminating an insulating substrate 7 with an insulating spacer 8 interposed therebetween. Insulating board 7
consists of a glass plate, acrylic plate, etc., and a polymer film 1
A rectangular electrode 10 is provided to intersect at right angles with the S pole 2 provided at the top.

Reference numeral 11 denotes an insulating dot-shaped spacer provided on the surfaces of the insulating substrate 7 and the electrode 10.

Next, the shrinkage state of the polymer film was investigated for the above-mentioned example and conventional example.

In the example, a polyester film with a thickness of 175 μm was used as the polymer film, and a transparent conductive film of ITO was formed on it to a thickness of 400 Å. When the polymer film in this state was heated at a temperature of 140° C. for 1 hour, the thermal shrinkage was 0.1% in the width direction and 0.3% in the longitudinal direction. After etching this polymer film, polyester-A
tf g-based thermosetting conductive ink! It was printed to a thickness of 8 μm and heated at 140° C. for 1 hour to form an extraction circuit. After heating, the polymer film did not exhibit any wavy bulges.

Further, the conditions of the conventional example are the same as those of the example except that the short sides of the rectangular electrodes provided on the polymer film are aligned in the longitudinal direction. After printing the conductive ink and heating it, the polymer film was examined and found to have undulating bulges.

(Effects of the Invention) As described above, according to the present invention, by forming a rectangular electrode on the surface of a polymer film with its long sides aligned with the longitudinal direction, thermal shrinkage can be reduced. A touch panel can be obtained in which the undulation can be prevented from rising in a wavy manner, dimensional accuracy is improved, and appearance defects can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view of a polymer film on which electrodes used in an embodiment of the present invention are formed, and FIG. 2 is a sectional view of a touch panel according to an embodiment of the present invention. 1...Polymer film, 2,10... as poles, 3.
...Long side, 4...Longitudinal direction, 7...Insulating substrate, 9...Touch panel. Patent applicant Hitachi Capacitor Co., Ltd. Figure 2

Claims (1)

[Claims] (1) In a touch panel in which at least one side is a polymer film and insulating substrates with electrodes provided on the surface are laminated,
A touch panel characterized in that a rectangular electrode is provided on a polymer film with its long sides aligned in the longitudinal direction of the polymer film.