JP2004119373A - Touch panel with adhesive layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel not hindering an electric inspection process before delivery and an appearance inspection process, generating no deterioration of the product caused by bending during the time before delivery or the time until mounted on a display surface after delivery. <P>SOLUTION: A touch panel main body is composed of an upper electrode plate having an upper electrode formed by arranging a transparent conductive film on a lower surface of an upper insulation base board composed of a transparent plastic film; and a lower electrode plate having a lower electrode formed by arranging a transparent conductive film on an upper surface of a lower insulation base board composed of a transparent plastic film, arranged so as to face the upper electrode plate interposing an air layer between electrodes. The touch panel has an adhesion layer for wholly adhering the above touch panel main body on a display and a separate supporting plate member thereof. The separate supporting part is made of a transparent plastic film having a flexural rigidity of 0.3 to 40 kgf×cm<SP>2</SP>at room temperature on condition that a width b of cross section is 12 cm. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention provides an adhesive layer that does not hinder the electrical inspection process and appearance inspection process before shipping, and that does not cause functional deterioration due to bending of the product before shipping or before being mounted on the display surface after shipping. With touch panel.

Conventionally, portable electronic devices equipped with displays such as cordless telephones, mobile phones, calculators, sub-notebook personal computers, PDAs (Personal Digital Assistants), digital cameras, video cameras, and professional communication devices, and monitors for personal computers, etc. 2. Description of the Related Art A touch panel is widely used as an input device mounted on the front surface and capable of performing various operations by pressing the surface with a pen or a finger while following instructions on a see-through screen.

The touch panel has an upper electrode plate in which an upper electrode 103 made of a transparent conductive film is formed on the lower surface of an upper insulating substrate 102 made of a transparent plastic film, and a transparent conductive film formed on the upper surface of a lower insulating substrate 104 made of a transparent glass plate or a transparent plastic film. The touch panel main body 101 includes a lower electrode plate on which a lower electrode 105 made of a film is formed, and the upper electrode plate and the lower electrode plate are arranged to face each other with an air layer 106 interposed between the electrodes. (See FIG. 2). In recent years, it has been important to reduce the thickness and weight of products such as the personal computers described above, and accordingly, there has been a demand for a reduction in the thickness and weight of the touch panel itself. Therefore, a film / film configuration rather than a film / glass configuration has been selected. Often. Reference numeral 108 denotes a double-sided tape.

The touch panel is entirely adhered to the surface of a display (not shown) as shown in Patent Literature 1, so that the touch panel is further provided with an adhesive layer 109 for adhering to the display and its separate layer. The sheet 110 (for example, a thin and rigid PET film having a thickness of about 50 μm and a bending elasticity of about 0.0038 kgf · cm ² ) is provided.
JP-A-10-222305

However, when the touch panel has the above-mentioned film / film configuration, various problems may occur during the electrical inspection process before shipping, the appearance inspection process, and finally until the touch panel is mounted on the display surface. .

That is, a touch panel having a film / film structure has a small overall thickness, and thus the touch panel as a whole is easily warped. In particular, when a hard coat layer is provided on the upper surface of the upper electrode plate, warpage tends to occur due to heating or the like during the manufacturing process. When the appearance inspection process is performed with the entire touch panel warped, it is determined that the Newton ring does not occur if the distance between the electrodes is uniform, but if the lower electrode plate of the touch panel is mounted flat on the display with the adhesive layer The distance between the electrodes may be non-uniform and Newton rings may occur. Conversely, if the distance between the electrodes is uneven while the entire touch panel is warped, it is determined to be a defective product that generates Newton rings. May not occur. As described above, the touch panel having the film / film structure has a problem that it is very difficult to make a determination in an appearance inspection process such as a Newton ring caused by warpage.

Further, in the electrical inspection process, as described above, the total thickness of the lower insulating substrate 104 and the separate sheet 110, and thus the total thickness of the product is small, the bending rigidity is small, and the touch panel is easy to bend. When used in common with the cassette rack type automatic inspection machine used for the touch panel, automatic inspection is difficult. In other words, when the touch panel with the adhesive layer at the bottom of the cassette rack is pushed out from the side with a pusher and taken out, and the touch panel with the adhesive layer taken out from the cassette rack is pushed with the pusher from the side to position on the jig. At that time, the touch panel with the adhesive layer is bent or detached from the jig.

Also, in other types of automatic or semi-automatic electric inspection machines, since the total thickness of the lower insulating substrate 104 and the separate sheet 110 is small, the bending rigidity is small and the touch panel is easily bent as described above, If foreign matter such as dust is present on the upper surface, a deformation occurs such that the lower insulating substrate locally projects to the upper insulating substrate side along the foreign matter. As a result, even if it is a non-defective product, the lower electrode plate and the upper electrode plate come into contact with each other, resulting in a poor insulation judgment, or the lower electrode plate and the upper electrode plate coming very close to each other even if they do not come into contact with each other. If the linearity is inspected while tracing the input surface as in the above, an input is made in the vicinity of the input location, and a defect is determined. To reduce these, it is conceivable to perform the electrical inspection process in a clean room, but it is costly and still not perfect.

Furthermore, even if the electrical inspection process and the appearance inspection process are successfully completed, the touch panel is thin and has a small bending rigidity, and the touch panel is easily bent. There is a problem in that some load is applied during this period, and cracks due to bending of the product cause functional deterioration of the transparent conductive film and the like.

Therefore, an object of the present invention is to solve the above-mentioned problems, to prevent an electrical inspection process before shipping and a visual inspection process from being hindered, and to wait until the device is mounted on the display surface after shipping. Another object of the present invention is to provide a touch panel with an adhesive layer that does not cause functional deterioration due to product bending.

In order to achieve the above object, the present invention provides an upper electrode plate in which an upper electrode formed of a transparent conductive film is formed on the lower surface of an upper insulating substrate formed of a transparent plastic film, and a transparent plastic film. A lower electrode composed of a transparent conductive film is formed on an upper surface of a lower insulating substrate, and a touch panel body including an upper electrode plate and a lower electrode plate disposed opposite to each other with an air layer between the electrodes is entirely covered with a display. A touch panel with an adhesive layer having an adhesive layer for bonding and a separate support plate member thereof, wherein the separate support plate member has a flexural rigidity at room temperature of 0.3 to 40 kgf when its cross-sectional width b is 12 cm. It is configured so as-is transparent plastic film cm ^2.

According to a second aspect of the present invention, the separate support plate member is a transparent plastic film having a bending stiffness at room temperature of 1.5 to 8.0 kgf · cm ² when the cross-sectional width b is 12 cm. A touch panel with an adhesive layer according to the first aspect is provided.

According to a third aspect of the present invention, the adhesive layer according to the first or second aspect, wherein the adhesive layer comprises an acrylic adhesive layer, a core material made of polyethylene terephthalate, and a silicon-based self-adhesive layer. Provide a touch panel with an adhesive layer.

Since the touch panel with an adhesive layer of the present invention is configured such that the bending rigidity at room temperature when the cross section width b is 12 cm is a transparent plastic film of 0.3 to 40 kgf · cm ² , the touch panel with the adhesive layer of the present invention is electrically operated. In the inspection step, since the rigidity of the entire product is increased by using the separate support plate member having the specific range of bending rigidity as described above, the cassette rack conventionally used for the film / glass structure touch panel is used. Automatic inspection is easy even when the system is shared with an automatic inspection machine of the system. That is, when the touch panel with the adhesive layer is pressed from the side direction by the pusher, the touch panel with the adhesive layer does not bend or separate from the jig unlike the related art.

Also, in other types of automatic or semi-automatic electrical inspection equipment, the rigidity of the entire product is increased by using the separate support plate member having a specific range of bending rigidity as described above, so that the electrical inspection equipment has a jig. Even if there is a foreign substance such as dust, the lower insulating substrate bends gently, and there is no deformation that locally projects to the upper insulating substrate side along the foreign substance unlike the related art. As a result, the electrical inspection process can be performed outside the clean room without erroneous determination of insulation and linearity.

In addition, since the rigidity of the entire product is increased by using the separate support plate member having a specific range of bending rigidity as described above, even if warpage occurs in the upper insulating substrate, the entire touch panel is in the same manner as in the related art. It is possible to accurately determine the quality in the appearance inspection process such as a Newton ring without warping.

In addition, since the rigidity of the entire product is increased by using the separate support plate member having a specific range of bending stiffness as described above, before shipment or before being mounted on the display surface after shipment. Even if some load is applied, cracks such as the transparent conductive film due to bending of the product do not occur.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, 1 is a touch panel body, 2 is an upper insulating substrate, 3 is an upper electrode disposed on the inner surface of the upper insulating substrate 2, 4 is a lower insulating substrate disposed opposite to the upper insulating substrate 2, and 5 is a lower insulating substrate. A lower electrode disposed on the inner surface of the substrate 4; an air layer 6 interposed between the upper electrode 3 and the lower electrode 5; a double-sided tape 8 for bringing the periphery of the upper insulating substrate 2 and the lower insulating substrate 4 into close contact with each other; Reference numeral 9 denotes an adhesive layer disposed on the outer surface of the lower insulating substrate 4, and reference numeral 10 denotes a separate support plate member having both the function of a separate sheet and the function of a support plate disposed on the adhesive layer 9. Here, the separate sheet of the general-purpose pressure-sensitive adhesive sheet only has to play the role of preventing adhesion until immediately before bonding, does not require the thickness of the present invention close to a "plate", and has no supporting function at all. . Therefore, the separate sheet of the prior art and the plate-like separate support plate member of the present invention having a support function are completely different.

The touch panel with an adhesive layer shown in FIG. 1 is composed of an upper electrode plate in which an upper electrode 3 composed of a transparent conductive film is formed on the lower surface of an upper insulating substrate 2 composed of a transparent plastic film, and a transparent plastic film. FIG. 3 shows a touch panel main body 1 in which a lower electrode 3 made of a transparent conductive film is formed on the upper surface of a lower insulating substrate 4 and includes an upper electrode plate and a lower electrode plate opposed to the electrodes via an air layer. In the touch panel with an adhesive layer having the adhesive layer 9 for completely adhering to the display 20 and the separate support plate member 10, the bending rigidity at room temperature when the width b of the cross section of the separate support plate member 12 is 12 cm is shown. It is a transparent plastic film of 0.3 to 40 kgf · cm ² .

The transparent plastic film of each of the upper insulating substrate 2 and the lower insulating substrate 4 of the touch panel main body 1 includes polyethylene terephthalate resin (PET), polycarbonate resin (PC), polyester sulfone resin (PES), polyarylate resin (PAR), Alternatively, a transparent plastic film such as a norbornene resin can be used. Note that the upper insulating substrate 2 and the lower insulating substrate 4 may have a multilayer structure. The thickness of the upper insulating substrate 2 and the lower insulating substrate 4 is preferably about 75 to 200 μm. Further, a hard coat layer may be formed on the upper surface of the upper insulating substrate 2. The hard coat layer includes an inorganic material such as a siloxane-based resin, or an organic material such as an acrylic epoxy-based or urethane-based thermosetting resin or an acrylate-based photocurable resin. The appropriate thickness of the hard coat layer is about 1 to 7 μm. Further, the upper surface of the upper insulating substrate 2 may be subjected to a non-glare treatment for preventing light reflection. For example, the transparent insulating base material and the hard coat layer are subjected to unevenness processing, or an extender, fine particles such as silica and alumina are mixed in the hard coat layer.

Examples of the material of the transparent conductive film used for the upper electrode 3 and the lower electrode 5 include tin oxide, indium oxide, antimony oxide, zinc oxide, cadmium oxide, metal oxides such as ITO, gold, silver, copper, tin, and the like. There are metals such as nickel, aluminum, and palladium. As a method for forming these transparent conductive films, a vacuum evaporation method, a sputtering method, an ion plating method, a CVD method, or the like is used.

回路 Further, a circuit having a predetermined pattern such as a bus bar or a lead wire is formed on the electrode side surface of the upper electrode plate and the lower electrode plate (not shown). As a material for the circuit, for example, a conductive material such as a metal such as gold, silver, copper, or nickel, or carbon, or a known material can be used. These forming methods include printing methods such as screen printing, offset printing, gravure printing, and flexographic printing, a photoresist method, and a brush coating method.

The upper electrode plate and the lower electrode plate are usually separated from each other by a spacer (not shown) formed on the surface of the upper electrode 3 or the lower electrode 5, and the upper electrode plate and the finger are placed on the upper electrode plate. Only when pressing from above, the upper electrode 3 and the lower electrode 5 come into contact with each other and input is performed. The spacer can be obtained by forming a transparent photocurable resin into fine dots by a photo process. Further, a large number of fine dots can be formed by a printing method to be used as a spacer. The height of the spacer is usually 2 to 10 μm.

The pressure-sensitive adhesive layer 9 for completely bonding the touch panel body 1 to the display 20 includes a pressure-sensitive adhesive sheet composed of a laminate of a silicon-based pressure-sensitive adhesive layer / a core material composed of polyethylene terephthalate / an acrylic pressure-sensitive adhesive layer ( 5 described later), only the silicone-based pressure-sensitive adhesive layer, or only the acrylic-based pressure-sensitive adhesive layer. Usually, the thickness of the adhesive layer 9 is preferably about 20 to 100 μm. In addition, the surface of the adhesive layer 9 on the side that is entirely adhered to the display 20 has the separate support plate member 10. After the separate support plate member 10 is peeled off from the adhesive layer 9, the adhesive layer 9 is entirely adhered to the display 20, as shown in FIG.

The feature of the embodiment of the present invention is that the separate support plate member 10 is a transparent plastic film having a flexural rigidity at room temperature of 0.3 to 40 kgf · cm ² when the cross-sectional width b is 12 cm. . The bending stiffness of the separate support plate member 10 is expressed by tensile modulus × I (second moment of area (cm ⁴ )). When the cross section of the separate support plate member 10 is rectangular, I (second moment of area) = represented by bh ^3/12. b is the width of the cross section (cm), and h is the height of the cross section (cm). The normal temperature means 20 to 25 ° C. In the present invention, even when the width b of the cross section of the actually used separate support plate member 10 is not 12 cm, the bending stiffness value is obtained based on the above equation on the assumption that b = 12 cm. Here, the reason why the width b of the cross section is set to 12 cm is to express the bending rigidity of the separate support plate member 10 by the thickness and the elastic modulus of the material. An expression representing the bending rigidity of the separate support plate member 10 is as follows:
Flexural stiffness = tensile elastic modulus × ^bh 3/12
Is represented by Since b is the width of the cross section (cm) and h is the height of the cross section (cm), if b is fixed to 12 cm according to the denominator value of 12 in the equation, only the thickness and elastic modulus of the material are obtained. Can represent the bending rigidity. The reason for setting the room temperature is that the inspection work environment and the peeling work environment of the separate support plate member 10 are the normal temperature environment (the elastic modulus of the material of the separate support plate member 10 changes depending on the environmental temperature, Flexural rigidity also changes.) Further, when the width b of the cross section of the separate support plate member 10 is 12 cm, a more preferable range of the bending stiffness at room temperature is 1.5 to 8.0 kgf · cm ² .

If the flexural rigidity is less than 0.3 to 8.0 kgf · cm ² , the same problem as the conventional touch panel with an adhesive layer may occur. If the bending stiffness exceeds 40 kgf · cm ² , when the separate support plate member 10 is peeled off from the adhesive layer 9, there is a possibility that the touch panel main body 1 may be greatly bent and cracks may occur in the transparent conductive film. In addition, if the bending rigidity is 1.5 to 8.0 kgf · cm ² , the above problem is less likely to occur.

に よ り By setting the bending stiffness of the separate support plate member 10 within the above range, the problem that occurred in the electrical inspection process and the appearance inspection process before shipping does not occur.

That is, in the electrical inspection process, the rigidity of the entire product is increased by using the separate support plate member 10 having a specific range of bending rigidity as described above. Automatic inspection can be easily performed even when the automatic inspection machine is used in common with a cassette rack type automatic inspection machine. That is, when the touch panel with the adhesive layer is pressed from the side direction by the pusher, the touch panel with the adhesive layer does not bend or separate from the jig unlike the related art.

Also, in other types of automatic or semi-automatic electric inspection machines, the rigidity of the entire product is increased by using the separate support plate member 10 having a specific range of bending rigidity as described above. Even if there is foreign matter such as dust on the lower insulating substrate, the lower insulating substrate gently bends, so that there is no deformation that locally projects to the upper insulating substrate side along the foreign material as in the related art. As a result, the electrical inspection process can be performed outside the clean room without erroneous determination of insulation and linearity.

In addition, since the rigidity of the entire product is increased by using the separate support plate member 10 having a specific range of bending stiffness as described above, even if warpage occurs in the upper insulating substrate, the entire touch panel as in the prior art is generated. However, it is possible to accurately determine the quality in the appearance inspection process such as a Newton ring without warping.

In addition, since the rigidity of the entire product is increased by using the separate sheet 10 having the bending stiffness in the specific range as described above, some sort of time is required before shipping or before mounting on the display surface after shipping. Even if a load is applied, cracks such as a transparent conductive film due to bending of the product do not occur.

As the transparent plastic film used for the separate support plate member 10, for example, polypropylene resin (PP), polyethylene terephthalate resin (PET), polycarbonate resin (PC), acrylonitrile resin (AC), or methyl methacrylate-styrene copolymer Resin or the like can be used. Since the separate support plate member 10 is finally removed and discarded, an inexpensive material such as PET, PC, or PMMA may be used. The thickness of the separate support plate member 10 can be freely selected as long as the thickness is within the range of the bending rigidity described above. As a specific numerical example, for example, a polycarbonate resin having an elastic modulus of 2300 MPa (23460 kgf / cm ³ ) has a thickness of 0.025 to 0.12 cm and a bending rigidity of about 0.37 to 40 kgf · cm ² . A preferred range is "a polycarbonate resin having a thickness of 0.04 to 0.07 cm and a flexural rigidity of about 1.5 to 8.0 kgf · cm ² .

In the case where the surface of the adhesive layer 9 that is entirely bonded to the display 20 has a strong adhesive function (for example, when the acrylic adhesive layer 9 is provided), as shown in FIG. For example, a separate support plate member 10 on which a silicone release layer 25 is formed is used.

Further, as shown in FIG. 5, the adhesive layer 9 may be composed of an acrylic adhesive layer 9a, a core material 9b made of, for example, polyethylene terephthalate having a thickness of 38 μm, and a silicon adhesive layer 9c. . By using the silicon-based self-adhesive layer 9c, the touch panel and the display can be detached again, and maintenance is facilitated. In addition, by combining with the non-peelable acrylic adhesive layer 9a, the re-peelable surface can be specified as either the lower surface of the touch panel or the upper surface of the display.

タ ッ チ パ ネ ル The size of the touch panel with an adhesive layer having the above configuration includes 100 mm × 75 mm, 80 mm × 60 mm, 50 mm × 40 mm, and the like.

(5) A PET film having a thickness of 125 μm was used as a lower insulating substrate, and a lower electrode made of an ITO film having a thickness of 0.02 μm was formed on the upper surface thereof by sputtering to obtain a lower electrode plate. On the other hand, a PET film having a thickness of 200 μm was used as an upper insulating substrate, and an upper electrode made of an ITO film having a thickness of 0.02 μm was formed on the lower surface by sputtering to form an upper electrode plate, and an upper electrode of the upper insulating substrate was formed. An acrylate-based photocurable resin was coated on a surface opposite to the surface with a roll coater to a thickness of 5 μm to provide a hard coat layer. Next, after a circuit of a predetermined pattern is formed on the upper electrode plate and the lower electrode plate by screen printing, the upper electrode plate and the lower electrode plate are disposed so as to face each other with an air layer between the electrodes, and both are disposed. The periphery was adhered with a double-sided tape having a thickness of 50 μm to obtain a touch panel body having a size of 80 mm × 60 mm.

A PC film having a flexural rigidity at room temperature of 2.9 kgf · cm ² when the thickness is 500 μm and the cross-sectional width b is 12 cm is used as the separate support plate member 10, and a silicon-based self-adhesive layer having a thickness of 40 μm is formed on one surface thereof. And a pressure-sensitive adhesive layer formed by sequentially laminating a core material made of polyethylene terephthalate having a thickness of 38 μm and an acrylic pressure-sensitive adhesive layer having a thickness of 20 μm (see, for example, FIG. 5). The laminated film was entirely adhered to the lower surface of the lower electrode plate of the touch panel main body by the adhesive layer to obtain a touch panel with an adhesive layer.

(Comparative Example) With an adhesive layer in the same manner as in Example 1 except that a PET film having a flexural rigidity at room temperature of 0.0038 kgf · cm ² when the thickness was 50 μm and the cross-sectional width b was 12 cm was used as a separate sheet. Touch panel.

In the touch panel of Comparative Example 1, since the bending rigidity of the separate sheet is small, a large problem occurs in the electric inspection process and the appearance inspection process before shipping, and the touch panel is mounted on the display surface until shipping or after shipping. In the meantime, functional deterioration due to bending of the product occurred. On the other hand, in the touch panel of the first embodiment, since the bending rigidity of the separate support plate member 10 was large, the problem as in the first comparative example did not occur. ,

It is a sectional view showing the touch panel with an adhesion layer concerning one embodiment of the present invention. It is sectional drawing which shows the touch panel with an adhesive layer which concerns on a prior art. FIG. 3 is a cross-sectional view showing a state in which a separate support plate member of the touch panel with an adhesive layer according to the embodiment of the present invention is peeled off from the adhesive layer, and then the adhesive layer is entirely adhered to the display. It is sectional drawing which shows the touch panel with an adhesive layer which concerns on the modification of the said embodiment of this invention. It is sectional drawing which shows the touch panel with an adhesive layer which concerns on another modification of the said embodiment of this invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Touch panel main body 2 Upper insulating substrate 3 Upper electrode 4 Lower insulating substrate 5 Lower electrode 6 Air layer 8 Double-sided tape 9 Adhesive layer 10 Separate support plate member 20 Display 101 Touch panel main body 102 Upper insulating substrate 103 Upper electrode 104 Lower insulating substrate 105 Lower electrode 108 Double-sided tape 109 Adhesive layer 110 Separate sheet

Claims (3)

An upper electrode plate in which an upper electrode made of a transparent conductive film is formed on the lower surface of an upper insulating substrate made of a transparent plastic film, and a transparent conductive film formed on the upper surface of a lower insulating substrate made of a transparent plastic film. And a separate support plate for completely bonding a touch panel body including the upper electrode plate and the lower electrode plate facing each other with an air layer between the electrodes to the display. A touch panel with an adhesive layer having a member, wherein the separate support plate member is a transparent plastic film having a bending stiffness at room temperature of 0.3 to 40 kgf · cm ² when the cross-sectional width b is 12 cm. Characteristic touch panel with adhesive layer. ^2. The touch panel with an adhesive layer according to claim 1, wherein the separate support plate member is a transparent plastic film having a bending stiffness at room temperature of 1.5 to 8.0 kgf · cm ² when the cross-sectional width b is 12 cm. . The touch panel with an adhesive layer according to claim 1 or 2, wherein the adhesive layer comprises an acrylic adhesive layer, a core material made of polyethylene terephthalate, and a silicon-based self-adhesive layer.

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