JP2012226688A - Decorative cover glass integrated type touch panel sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a decorative cover glass integrated type touch panel sensor that secures light shielding and reduces the film thickness of a decorative layer since when a decorative part is formed on a glass substrate by a screen printing method, a screen print layer needs to be large in film thickness so as to satisfy requested light shielding characteristics and screening characteristics only with the decorative layer which is formed by screen printing, and it is, however, difficult to form an overcoat layer and a touch panel sensor layer on a decorative cover glass because of a film thickness step between the decorative part and an opening part as an obstacle.SOLUTION: There is provided the decorative cover glass integrated type touch panel sensor which has the decorative layer, overcoat layer, and touch panel sensor layer formed in order on the glass substrate as the cover glass, the decorative layer comprising a colored resin layer and a metal film layer formed in order by screen printing.

Description

  The present invention relates to a touch panel type input device that is used by being overlapped with a display device such as a liquid crystal display device and an organic EL, and particularly relates to a technique for improving a shielding ability by a decorative pattern formed by a screen printing method.

  2. Description of the Related Art In recent years, touch panel type input devices (hereinafter simply referred to as touch panels) have been adopted for operation units of various electronic devices such as mobile phones, portable information terminals, and car navigation systems. The touch panel is used as an input device that detects a contact position of a fingertip or a pen tip on a display surface of a display panel such as a liquid crystal display device. There are various types of touch panels, such as a resistance film type and a capacitance type, depending on the structure and detection method.

  A capacitive touch panel has a matrix-like translucent conductive film formed on a single glass substrate, and is sensitive to changes in capacitance induced by the contact of a finger or the like between the electrodes. The position to be touched on the touch panel is specified by detecting it as a current change, and there is an advantage that it has a higher transmittance than the resistance film type input device conventionally used.

  In a liquid crystal display device including a touch panel, the touch panel is mounted and fixed on a polarizing plate of a display panel of the liquid crystal display device after alignment (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

  As a method of fixing the touch panel to the liquid crystal display device, a method of fixing the touch panel by laying a cushion rubber with an adhesive having a thickness of about 0.5 mm or more on the outer periphery of the display panel or a transparent adhesive between the display panel and the touch panel. A method of pasting the entire surface is adopted.

  In the method of attaching the entire surface with a liquid crystal display device, a touch panel and a transparent adhesive (for example, see Patent Document 3), the air gap layer is eliminated, and the refractive index of the transparent adhesive is close to the glass substrate of the touch panel. By selecting and reducing the reflectance, the screen became brighter. However, when using a photo-curing type for the transparent adhesive, it is necessary to inspect before the curing process, and if there are bubbles or foreign objects, it is necessary to peel off without curing, wash and re-apply was there.

  A casing in an electronic device such as a mobile phone is generally a flat casing formed by combining a front casing and a rear casing made of synthetic resin. Specifically, the front casing is provided with a display window opening in which a liquid crystal display device or the like is disposed, and a protective panel (in order to protect the surface of the display device provided below the display window from an impact or the like) Cover glass) is fixed by fusion or the like (see, for example, Patent Document 4).

  By the way, when viewing the display unit from the user side in a mobile phone or the like, information and images are not displayed on the entire surface of the glass, but there are black portions on the outer periphery of the cover glass so as to partition the display unit. The display is made inside this. Although this frame portion is called a decoration portion, the display portion is defined in a predetermined shape such as a quadrangular shape and concealed so that a portion that is inconvenient (such as a touch panel wiring portion and a wiring portion of a display device) is not visible. There is a function.

Conventionally, the cover glass decorated and the touch panel sensor are manufactured separately and finally bonded and integrated. On the other hand, a decorative part is formed on the cover glass using the resin material for the black matrix used for manufacturing the color filter substrate, and then, on the decorative part, prevention of degassing, ensuring insulation, and improving flatness For this purpose, there is a decorative cover glass-integrated touch panel sensor structure in which an overcoat layer made of a transparent insulating material is provided and a touch panel sensor is further formed thereon.

  In any case, the decorative part is very important as an appearance decoration member of the portable terminal device display part as a direct contact, and the need for multi-coloring is increasing as a result of the emphasis on design. ing. For this reason, conversion from a black black resin material for black matrix to a screen printing method that can use printing inks with a large degree of freedom in color selection is being attempted.

  As described above, the decoration part formed on the glass substrate serves to shield the wiring part of the display device, but at the same time, the decoration part also has a light shielding property so that light does not escape from the display device. Is essential. For this reason, when forming a decoration part by screen printing, in order to improve light-shielding property, the light-shielding characteristic requested | required by laminating | stacking several layers is seen. In general, the display panel has various sizes, but the touch panel is manufactured by a single-wafer method in which a plurality of touch panels are arranged on a large substrate at the same time to improve production efficiency. Therefore, when the decorative part is laminated in many layers, the thickness of the decorative part becomes high, and the step of the decorative part becomes a barrier during resist coating in each process by spin coating method in the touch panel sensor forming process. Therefore, kelamula occurs in the coating film, and it is difficult to ensure good coating quality.

  This is because, in the touch panel sensor forming process, if various resists cannot be applied uniformly over the entire glass substrate, the touch panel sensor does not work properly and disconnects, resulting in a malfunction of the touch panel.

JP 2008-33777 A JP 2007-178758 A JP 09-274536 A JP 2007-323092 A JP 2004-5540 A

  The present invention relates to the structure of a decorative cover glass-integrated touch panel sensor, and the number of decorative layers formed by screen printing when the decorative portion is formed on a glass substrate by a screen printing method. And reducing the number of layers of the screen printing layer by decorating with a metal film on the decorative part formed by screen printing. An object of the present invention is to provide a structure of a decorative cover glass-integrated touch panel sensor in which a structure for reducing the film thickness of the entire part is introduced.

  The present invention has a problem of ensuring sufficient light-shielding properties / shielding properties and solving the thickness of the decorative layer, on the glass substrate serving as a cover glass, a decorative layer, an overcoat layer, The touch panel sensor layer is a decorative cover glass-integrated touch panel sensor configured in order, and the decorative layer is formed by sequentially forming a colored resin layer and a metal film layer formed by screen printing. It consists of the structure of a decorative cover glass integrated touch panel sensor.

  Until now, when forming a decorative layer only by screen printing, in order to satisfy the required light shielding characteristics, for example, when an optical density characteristic value OD (optical density) value of about 4 to 5 or more is required, In the case of white ink formed by a screen printing method, it is necessary to laminate about 80 to 120 μm or more.

  In the cover glass substrate where the decorative layer is present, there is a film thickness difference between the portion where the decorative layer is present and the portion where the decorative portion is not present, and this step becomes a barrier, and the application of the overcoat material by the spin coat method At this time, since vignetting or the like occurs, it is difficult to ensure the quality of the coating film as a planarizing film. Furthermore, the formation of the touch panel sensor layer on the cover glass having the decorative layer has been difficult because it cannot avoid the disconnection of the wiring.

  That is, it is a specific problem of the present invention to solve the thickness problem of the decorative layer while ensuring the required light-shielding characteristics / shielding characteristics.

  The invention of claim 1 is a decorative cover glass-integrated touch panel sensor, in which a decorative layer having a predetermined shape such as a quadrangle is formed on the rear surface on the viewing side of the glass substrate to be the cover glass. A decorative cover glass-integrated touch panel sensor in which an overcoat layer is provided to flatten a film thickness difference between a portion with a decorative layer and a portion without a decorative layer, and then a touch panel sensor layer is formed in order, The layer is characterized by a structure in which a colored resin layer and a metal film layer formed by screen printing are sequentially formed.

  The invention of claim 2 is characterized in that the metal film layer constituting the decorative layer is formed by sputtering, patterned by etching, and covers a colored resin layer. It is a decorating cover glass integrated touch panel sensor as described in 1 invention.

  The invention of claim 3 is that the colored resin layer constituting the decorative layer is suppressed by the metal film layer, and light from the front surface and the back surface of the decorative cover glass-integrated touch panel sensor is shielded. The decorative cover glass-integrated touch panel sensor according to claim 1 or 2, wherein the decorative cover glass is an integrated touch panel sensor.

  According to a fourth aspect of the present invention, the overcoat layer made of an insulating material is used to flatten a film thickness difference between a region where the decorative layer is present and a region where the decorative layer is not present, and a colored resin layer formed by screen printing. 4. The gas according to claim 1, wherein the gas emitted from the container is sealed, and the metal film layer of the decoration layer and the touch panel sensor layer are electrically insulated from each other. A decorative cover glass-integrated touch panel sensor according to any one of the inventions.

  With the structure of the decorative cover glass integrated touch panel sensor in the present invention, the number of decorative layers formed on the glass substrate is reduced by performing back pressing with a metal film on the decorative part formed by screen printing. It is possible to reduce and secure the required light shielding characteristics.

  Thereby, the whole film thickness of the decoration layer became thin, and preparation of the decoration cover glass integrated touch panel sensor which directly forms a touch panel sensor in a decoration cover glass was attained.

With the structure of the decorative cover glass-integrated touch panel sensor according to the present invention, the overcoat layer can be uniformly and evenly applied on the glass substrate on which the decorative layer is formed, and a flat overcoat film surface is obtained. It is done. As a result, the decoration part is completely covered, so there is no degassing from the decoration part, the touch panel sensor can be processed on a flat overcoat, and the touch panel sensor can be formed without disconnection. became.

  Moreover, the decoration part of various colors can be formed by screen printing. Therefore, there is an effect that a decorative cover glass-integrated touch panel sensor with high quality, high reliability and high design can be provided at a low price.

  The decorative cover glass-integrated touch panel sensor according to the first aspect of the present invention is an integrated decoration of the decorative cover glass and the touch panel sensor without using an adhesive or an adhesive sheet. Has the effect that can be omitted.

  The decorative cover glass integrated touch panel sensor according to the invention of claim 1 is the touch panel sensor formed directly on the conventional glass substrate, wherein the touch panel sensor is formed directly on the back surface of the decorative cover glass substrate. Compared with the structure which bonds together, it has the effect that a glass base material can be reduced.

  In the invention of claim 1, claim 2 and claim 3, the decorative layer is formed by sequentially providing a screen print layer formed on a glass substrate and a light-shielding metal layer on the print layer. This is a touch panel sensor with a decorative cover glass that is characterized by the fact that it is extremely thin, about 1000 to 3000 mm (angstrom), but has a high light shielding property, instead of securing the light shielding property by laminating screen printing ink layers. By using a metal vapor-deposited film such as (molybdenum-aluminum-molybdenum), a decoration corresponding to a frame portion other than a display opening formed by a decoration layer in a cover glass of a mobile terminal device such as a mobile phone The part has a shielding effect on the display device wiring below and a light shielding effect.

  The inventions of claim 1, claim 2 and claim 3 use light-shielding properties by using a very thin metal deposited film layer instead of a conventional multi-layered screen printing ink layer to ensure light-shielding properties. In addition, the thickness of the decorative layer can be reduced, so that flattening using an overcoat material is possible, and the touch panel sensor layer can be directly formed on the decorative cover glass. .

  The overcoat layer according to the invention of claim 1 and claim 4 is provided so as to cover the decorative layer that is a convex portion and the opening portion that is a concave portion in the decorative layer, and the surface state thereof is It is characterized by being flattened so as to be horizontal or flat, and has an effect of preventing disconnection of the touch panel sensor wiring when the touch panel sensor is formed on the overcoat layer.

FIG. 1A is a schematic cross-sectional view illustrating the structure of a decorative cover glass-integrated touch panel sensor according to the present invention. The decorative layer includes a screen printing layer formed by a screen printing method and a decorative layer on the screen. The metal vapor deposition layer of MAM (molybdenum-aluminum-molybdenum) is provided by lamination, and the thickness thereof is about 5 to 20 μm. (B) of a figure is a structural cross-sectional schematic explaining the structure of the decoration layer which becomes this invention on a cover glass substrate. (C) of FIG. 1 is a schematic cross-sectional view of a decorative cover glass formed by a screen printing method, and the decorative layer is a multi-layered laminate for securing light-shielding properties by screen printing ink. The thickness is about 120 μm. FIG. 2 is a schematic structural cross-sectional view of a combination of a decorative cover glass integrated touch panel sensor and a liquid crystal display device according to an embodiment of the present invention. FIG. 3 shows a display device including a transparent touch switch and a liquid crystal display element according to Patent Document 3, in which a transparent adhesive is filled between the display surface of the liquid crystal display element and the back surface of the input area of the touch switch. 1 is a schematic cross-sectional view of a display device in which a touch switch and a liquid crystal display element are bonded. FIG. 4 is a schematic structural cross-sectional view of an image display device with a touch panel in which the interface between the display panel and the touch panel according to Patent Document 5 is brought into close contact with each other via an adhesive layer.

  In the present invention, a decorative portion in which a frame by a decorative layer of a predetermined shape such as a rectangle is formed on the back surface with respect to the viewing surface of the cover glass substrate, and a decoration corresponding to the inside of the predetermined decorative layer is applied. There is an opening for a display window that is not provided, and a decoration layer that forms the first decoration part, an overcoat layer made of an insulating material on the decoration layer, and a touch panel sensor layer are sequentially provided.

  The decorative layer is a screen printed layer on a glass substrate and a metal thin film layer having light shielding properties on the printed layer.

  The overcoat layer is provided so as to cover the decoration portion formed from the decoration layer and the opening, and the decoration portion and the opening so that the surface state thereof is horizontal or flat. The film thickness step is flattened.

  The touch panel sensor layer on the overcoat layer is provided by a projected capacitive method.

  The decorative layer is a decorative layer that forms a frame portion that is an outer periphery of an opening for a display window that is not decorated, and the decorative layer is a screen ink layer (layer thickness) formed by a screen printing method. 5 to 20 [mu] m) and a light-shielding metal thin film layer (layer thickness 1000 to 3000 mm) deposited thereon.

  The metal thin film layer is formed by, for example, etching MAM (molybdenum-aluminum-molybdenum) or the like so as to have a film thickness of about 1000 to 3000 mm by a sputtering method or the like and then having the same shape as the screen printing pattern. Pattern formation is performed, and the frame that is the outer peripheral portion of the opening, that is, the upper layer of the decorative portion.

  That is, the total film thickness of the decorative layer, which is a frame on the outer periphery of the opening, formed by laminating a screen ink layer printed on the cover glass by a screen printing method and the metal thin film layer is 80 to 120 μm in the related art. Compared to the above, the film thickness is reduced to about 1/6 to 1/10.

  The overcoat layer made of an insulating material on the decorative layer can be formed using, for example, a thermosetting type or an ultraviolet curable type made of an acrylic or siloxane resin.

  The overcoat layer is provided on the decorative layer provided on the cover glass. When the decorative layer is thinned, the overcoat layer is applied by a spin coat method or the like. In addition, the surface is flattened with no irregularities in the surface state and is formed in a horizontal shape or a flat shape without generation of kerram.

For the formation of the transparent electrode of the touch panel sensor layer, various thin film forming methods such as a vacuum deposition method and a sputtering method can be appropriately selected. As a material for forming the transparent electrode, a material capable of forming a transparent conductive film is appropriately selected and used. For example, metal oxides made of oxides such as indium, tin and zinc and mixtures thereof are used. As the transparent electrode of the present invention, ITO (Indium Tin Oxide) can be preferably used.

  The thickness of the transparent electrode can be appropriately determined according to the purpose of use. Generally, in the case of a metal oxide transparent conductive film, it can be achieved by setting the thickness to about 150 to 1500 mm.

  When forming the transparent electrode, the surface of the overcoat layer can be subjected to an appropriate treatment such as an ultraviolet irradiation treatment, a plasma treatment, a bombardment treatment, or the like to improve the adhesion with the transparent electrode.

  Examples of the present invention will be described below.

  <Example 1> About the formation of the decoration part on the glass substrate used as a cover glass, it screen-printed by the screen-printing method on the 400mmx500mmx0.5t tempered glass substrate by which single-sided grinding | polishing and the tempering process were performed. A multi-faceted decorative part pattern formation was performed using a printing ink. Then, after making it dry at room temperature, it baked for 30 minutes at 150 degreeC. This operation was repeated three times to form a decorative pattern by screen printing of a three-layer stack having a film thickness of about 10 μm to 15 μm.

  A MAM (molybdenum-aluminum-molybdenum) layer was formed by sputtering on the substrate on which the decorative pattern was formed with screen printing ink so that the film thickness was about 1000 to 3000 mm. The MAM layer is patterned so that the MAM layer has the same shape on the decorative pattern formed by screen printing by a known etching method so that the MAM layer has the same shape on the decorative pattern by screen printing. A decorative layer was formed.

  In the embodiment, MAM is used, but other than this, Al, Cr, chromium oxide (CrOx), etc., may be appropriately selected and used.

  In order to reduce the film thickness difference between the region where the decorative layer was formed and the region where the decorative layer was not present, an acrylic photosensitive resin was used and the surface was flattened by overcoating. In the case of multi-sided attachment, since it is desired to form a single piece by a chemical etching process in a subsequent substrate cutting process, it is necessary to expose the glass surface as a base material between each piece. For this reason, the overcoat layer was formed so that each part corresponding to each piece was covered with an overcoat layer having a predetermined shape.

  A MAM film was formed on the overcoat layer by sputtering, and a MAM wiring pattern was formed by etching. Next, an insulating layer having a predetermined pattern was formed by using a known photolithography method using an insulating film material (manufactured by JSR; NN901 material). Thereafter, an ITO (indium tin oxide) layer was formed by sputtering, and patterning was performed by an etching method so that a predetermined pattern was obtained. Furthermore, a protective film having a predetermined pattern was formed by using a transparent protective film material (manufactured by JSR; NN901 material) by a known photolithography method, and a capacitive touch panel sensor layer was formed.

  The decorative cover glass-integrated touch panel sensor device formed by the multi-sided attachment was cut by a chemical etching method so as to be an individual piece.

  The cutting method is not limited to the chemical etching method, and may be appropriately selected according to the application such as a scribe cutting method or a laser cutting method.

1: Glass substrate (cover glass)
2: Screen printing ink layer (colored resin layer)
3: Metal film layer 4: Overcoat layer 5: Touch panel sensor layer 6: Cushion rubber with adhesive 7: Liquid crystal cell 8: Polarizing plate 9: Backlight 10: Decorated cover glass integrated touch panel sensor 11: Liquid crystal display device 12: Transparent touch switch 13: Transparent adhesive 14: Polarizing plate 15: Glass substrate 16: Liquid crystal layer 17: Hard coat layer 18: Upper substrate (polymer film)
19: Transparent electrode 20: Dot spacer 21: Lower substrate (polymer film)
22: Adhesive layer 23: Polarizing film 24: Liquid crystal cell 25: Touch panel part 26: Display panel part

Claims (4)

A decorative cover glass-integrated touch panel sensor in which a decorative layer, an overcoat layer, and a touch panel sensor layer are sequentially formed on a glass substrate, wherein the decorative layer is a colored resin layer and a metal formed by screen printing. A decorative cover glass integrated touch panel sensor, wherein a film layer is formed in order. 2. The decorative cover glass-integrated touch panel sensor according to claim 1, wherein the metal film layer is formed by a sputtering method, patterned by an etching method, and covers a colored resin layer. The said decoration layer is a layer which is comprised by the colored resin layer and the metal film layer, and is a layer which shields the light from the front and back of a decorative cover glass integrated touch panel sensor. The touch panel sensor with integrated decorative cover glass described in 1. The overcoat layer is made of an insulating material, covers both the region where the decorative layer exists and the region where the decorative layer does not exist, and is formed by flattening the film thickness difference between the two regions. The decorative cover glass-integrated touch panel sensor according to any one of claims 1, 2, and 3.

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