JPH10293651A - Touch panel and spacer forming method and device for the panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer forming method to form a spacer that attains the highly precise print at a low cost and with excellent reliability with no fall-off of the print caused from a printed object such as a panel surface, etc., and also with no fatigue failure. SOLUTION: A recess part of a printing intaglio 1 is filled with the resin paste 5, and the intaglio 1 is adhered to a printed object. Then the intaglio 1 is separated from the printed object after the resin is hardened. Thus, a spacer is imprinted to the printed object from the resin. In regard to a more desirable method, the recess part of the intaglio 1 having a light shielding layer on its surface excluding the recess part is filled with the photo-setting resin paste 5. Then the intaglio 1 is adhered to the printed object and irradiated by the light on its side opposite to the side where the recess part exists. Thus, the resin 5 is hardened and the intaglio 1 is separated from the printed object. Then the photo-setting resin is imprinted to the printed object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a spacer in a touch panel, and a touch panel.

[0002]

2. Description of the Related Art Touch panels currently used include an electrostatic touch panel, an optical touch panel, and a resistive touch panel, and the most frequently used touch panel is a resistive touch panel. In the structure of the resistive touch panel, two transparent panels or sheets are arranged to face each other, and a transparent electrode layer made of ITO or the like is formed on the surface on the facing surface. A touch panel is composed of a pair of the two. When the touch panel is used on a liquid crystal display or a CRT display screen,
Most of the lower panel is made of glass, while the upper sheet needs to be pressed gently against the opposing panel when pressed, so many films of polycarbonate and PET with a thickness of more than one hundred and several microns are often used. used.
A hard coat layer is often applied to the uppermost surface of a film made of polycarbonate, PET, or the like to be pressed with a finger or a pen in order to impart durability.

[0003] There are roughly two types of coating patterns of transparent electrodes such as ITO, digital type and analog type. The digital method has been widely used in the past.
In the digital method, an elongated slit-shaped transparent electrode layer is formed on the upper and lower two panels by dividing them into strips or stripes like vertical stripes and horizontal stripes, respectively. This is intended to be detected as position data in the direction and the lateral direction. In this digital method, since the position can be specified if ON / OFF of each slit can be detected, a detection error does not occur due to a variation in resistance value due to uneven coating of the transparent electrode, and the reliability is high. However, the formation of a masking resist by photolithography and the division of the transparent electrode film by an etching process are required to insulate in a stripe shape, resulting in high cost. In addition, since the resolution is limited by the fineness of the division, there is a disadvantage that it is not suitable for fine position detection.

On the other hand, the analog system is a system which has recently become popular, and a transparent electrode layer is a transparent electrode in which a slit-type divided portion is not formed and the entire panel is continuous. Connection pads made of good conductors are provided on the upper and lower ends or the left and right ends of the transparent electrode so that one of the two panels flows in the vertical direction and the other panel flows in the horizontal direction on the transparent electrode. . When one point on this touch panel is pressed,
Since the resistance values of the upper, lower, left and right transparent electrodes are determined in proportion to the position from the pad, the ordinate is calculated by calculating based on the values. This method does not require slit processing compared to the digital method, and enables much finer position detection. However, if the dispersion of the coating thickness of the transparent electrode is large, the detection accuracy deteriorates.
Advanced control technology is required for O deposition and the like. If the coating thickness varies, the actually pressed position and the calculated position are shifted. If the variation in the coating thickness is even a part, the accuracy of detecting all positions in the direction of current flow will be degraded, but if there are multiple variations, all errors from the pad to the contact point are accumulated. The position detection accuracy will be further deteriorated.

Therefore, a hybrid system has recently appeared as a device that combines the advantages of a digital system, which is relatively easy to manufacture, and an analog system, which enables high-definition position detection. This is because the entire touch panel is divided into large sections by slitting it like a digital type, and within each section range, analog type position detection is performed to maintain high accuracy while maintaining position detection accuracy due to variations in resistance values. Is prevented from being accumulated outside the section range. Although this method has greatly improved the position detection accuracy, it has the disadvantage of extremely high manufacturing costs.

As described above, the detection method has changed in the search for high-precision position detection accuracy. However, other than the detection method, there is a spacer that greatly affects the cost and the detection accuracy. The function of the spacer on the touch panel is
When the panel is not pressed down so that the upper and lower transparent electrodes do not contact unnecessarily, the space between the upper and lower transparent electrodes is secured, and when pressed, the upper and lower transparent electrodes can easily contact, and the contact range is wide. Is to limit it. Since touch panels are often used on liquid crystal and CRT screens, they are required to have transparency, and the spacers, which are constituent elements thereof, are also required to have transparency. Therefore, a transparent resin is often used as a material for the spacer. Further, miniaturization of the spacer is required to improve the reliability and accuracy of detection and to make it difficult to visually recognize the spacer.

There are two methods of forming a spacer, a printing method and a photolithography method. In the printing method, a round hole is formed in a stainless steel plate by etching, or a round hole is formed in a nickel plate by electroforming, and this is used as a printing mask to print an ultraviolet curable resin or the like on a panel to be printed. , Spacers. Print masks used in such a printing method are an etching mask and an additive mask formed by electroforming, but each mask has advantages and disadvantages.

Although the above etching mask is less expensive than the additive mask in terms of manufacturing cost, the shape of the opening of the hole has a rough inner wall surface, and the hole is formed by etching from both upper and lower surfaces. Finally, there is a disadvantage that the central portion of the through hole becomes narrow. The roughness of the surface of the hole and the narrowness of the center of the hole greatly hinder the removability when printing with resin, etc., and the resin remains in the hole opening of the mask, resulting in "clogging" When the printing mask is released (released from the plate) from the panel, the resin is pulled between the panel and the mask, resulting in "stringing".
Occurs. As described above, if the removability is poor, it is naturally difficult to print with a small hole, so it is not suitable for manufacturing a high-definition touch panel, and furthermore, clogging becomes a defect of the spacer, and as a result, the touch panel is not supported by the spacer. A portion where the suspended area is quadrupled occurs, and the sensitivity varies greatly. In addition, since the stringing is interposed between the panels even when the panel is pressed down and hinders conduction,
After all, sensitivity will vary. Due to such a problem, the mask for spacer printing is shifting to an additive mask.

However, the additive mask has a defect called "hole loss". The additive mask is manufactured by laminating a dry film, which is a photoresist, on a substrate, which is an electrode for electroforming, while pressing it with a roll. Then, by developing, a female mold for electrolytic plating is made. An additive mask having a predetermined thickness is produced by growing the plating layer while immersing the substrate with the female mold in the electrolytic plating solution and oscillating it. The diameter of the mold is several tens of microns, and it is often peeled off and dropped from the substrate while being shaken in the electrolytic plating solution. This is the cause of the "hole loss", but the frequency is quite high, and this is a major problem in spacer production.

[0010] Further, it is difficult to make the hole shape uniform for both the etching mask and the additive mask, so that the amount of resin to be printed fluctuates, resulting in the fluctuating height of the spacer. Difficult to form.

[0011] The touch panel has two uses: a finger touch that can be detected by a wide range such as pressing with a finger, depending on the position detection accuracy and resolution; and a pen touch that performs fine detection such as characters and figures input by a dedicated pen. However, as described above, since the formation of the spacer by the printing method is not suitable for a high-definition one, it is actually used exclusively for finger touch.

In the photolithography method, another method of forming a spacer, a photosensitive resin is usually coated directly on the surface of the lower panel on the side of the transparent electrode, and has a pattern similar in shape to the spacer formed thereon. This is a method in which a photo film is brought into close contact, exposed and developed, and the remaining photosensitive resin is directly used as a spacer. Since this method can make much finer spacers than the printing method,
It is used exclusively to form pen-touch spacers for personal digital assistants, but most of the photosensitive resin is removed at the time of development, which increases material costs and costs wastewater treatment. There is a drawback of becoming high. Further, there is a case where a defect that the spacers fall off due to insufficient fixing force to the panel surface may occur.
In addition, hard plastic is often used as the material for the touch panel spacer, but in this case, the spacer becomes a lens-shaped spacer due to surface tension, so the load and stress are concentrated on the top of the head, and eventually fatigue fracture occurs And then be crushed. Such a plastic powder is dispersed on the surface of the surrounding transparent electrode and becomes an unnecessary insulating foreign matter, which has a disadvantage that a normal position cannot be detected at the time of pressing. In addition, since the height of the spacer changes depending on the broken spacer, there is a disadvantage that unnecessary erroneous input is caused.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such a problem and realize high-definition printing at a low cost, without falling off from a printing material such as a panel surface, and preventing fatigue. An object of the present invention is to provide a spacer forming method and a device for a touch panel capable of forming a highly reliable spacer without destruction.

Another object of the present invention is to provide a touch panel in which a spacer is not easily broken.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to fill a concave portion of a printing intaglio with a resin paste, adhere the intaglio to a printing material, and after the resin is cured, separate the intaglio and the printing material. This is achieved by a method for forming a spacer in a touch panel, wherein the resin is transferred to a printing substrate. In this method of forming a spacer in a touch panel, a concave portion of a printing intaglio is filled with a photocurable resin paste, the intaglio plate is brought into close contact with a printed material, and light is irradiated to cure the photocurable resin. It is preferable that the photocurable resin is transferred to the printing material by separating the printing material from the printing material, and in particular, the photocurable resin paste is filled in the concave portions of the printing intaglio having a light-shielding layer on the surface other than the concave portions. The intaglio plate is brought into close contact with the intaglio plate, and light is irradiated from the surface opposite to the surface having the concave portion of the intaglio plate to cure the photocurable resin. It is preferred to transfer to printed matter. Further, the printing intaglio is preferably a plastic plate, and it is particularly preferable to form a recess corresponding to a printing shape such as a spacer on a plastic plate by ablation using an excimer laser or SR light in an ultraviolet region of a synchrotron.

According to the method of forming a spacer in the touch panel of the present invention, the concave portion of the printing intaglio is filled with a resin paste, the intaglio is brought into close contact with the printing material, and after the resin is cured, the intaglio and the printing material are separated. By transferring the resin to the printing substrate by doing, in particular, filling the concave portion of the printing intaglio having a concave portion corresponding to the printing shape by ablation processing with a resin paste, bringing the intaglio plate into close contact with the printing substrate,
After the resin is cured, the resin is transferred to the printing material by separating the intaglio printing from the printing material, so that fine spacers and the like can be accurately formed on the panel, etc., which is the printing material. Since the number is small, a spacer or the like can be formed at low cost. In addition, after the resin filled in the recess is cured, the intaglio and the substrate are separated and the resin is transferred to the substrate, so that the resin adheres well to the substrate and does not fall off. Spacers or the like can be formed. In addition, by using a photo-curable resin paste as the resin paste, the photo-curable resin paste filled in the concave portion can be easily cured by light, and the resin can be more easily printed on a printing object to form a spacer or the like. Can be formed.

Further, the concave portion of the printing intaglio having a light-shielding layer on the surface other than the concave portion is filled with a photocurable resin paste, and the intaglio plate is brought into close contact with a printing object, and light is irradiated from the surface opposite to the surface having the concave portion of the intaglio. After irradiating to cure the photocurable resin,
According to the method of transferring the photocurable resin to the printing material by separating the intaglio and the printing material, the photocurable resin paste is applied on the intaglio surface other than the recess when filling the recesses with the photocurable resin paste. Remains or oozes out when the photocurable resin paste oozes out of the recess opening surface when the intaglio filled with the photocurable resin paste in the recesses is brought into close contact with the printing material. Since the light-curable resin paste in the portion other than the concave portion of the printing intaglio is not irradiated with light by the light-shielding layer on the surface other than the concave portion, only the photocurable resin paste filled in the concave portion can be cured. Thus, after the photocurable resin is transferred to the printing material, the uncured photocurable resin adhering to the printing material can be removed by washing, and the spacers and the like can be accurately formed on the printing material. Can be.

In order to manufacture a printing intaglio having a light-shielding layer on the surface other than the recess, a recess is formed in the plastic plate by ablation using a light-shielding mask layer having an opening formed on the plastic plate as a conformal mask. It is preferable to use the method described above. Thereby, the light-shielding mask layer when forming the concave portion by the ablation process can be used as a light-shielding layer that prevents light for curing the photocurable resin paste filled in the concave portion from irradiating portions other than the concave portion.

As the photocurable resin, an elastomer type ultraviolet curable resin is particularly preferable. When a spacer for a touch panel is formed, for example, by using the photocurable elastomer to form a spacer for the touch panel, the spacer is concentrated at the top of the head and subjected to a load or stress, so that the spacer is broken by fatigue and crushed. This prevents plastic powder from dispersing on the surface of the surrounding transparent electrode to form unnecessary insulating foreign substances, and can always detect a normal position when pressed. Also, since there is no change in the height of the spacer, unnecessary erroneous input does not occur.

In the method for forming a spacer in a touch panel according to the present invention, the printing intaglio is made into an endless belt-shaped intaglio, and the resin paste is filled into the recesses and the resin is transferred repeatedly, so that the resin is more efficiently printed on the substrate. , And a spacer or the like can be formed more efficiently.

Further, in the method for forming a spacer in a touch panel according to the present invention, when an intaglio filled with a photocurable resin paste in a concave portion is brought into close contact with a printing material, a printing pressure is applied from the upper surface of the intaglio printing plate to apply the resin paste. By promoting the fixation to the printing material, it is possible to prevent the printed material such as the spacer printed on the printing material from falling off, and to form a highly reliable spacer or the like.

Another object of the present invention is attained by a touch panel, wherein the spacer is formed of an elastic material. The touch panel is formed by the spacer forming method for a touch panel according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11, wherein a paste of an elastic polymer compound is used as a resin paste. Is desirable.

According to the touch panel of the present invention, since the spacer has elasticity, it is less likely to be broken than a spacer made of hard plastic. (Hereinafter, margin)

Here, as a method of charging the spacer material into the concave portion, it is possible to use a remelting method. That is, as in the case of the remelt method, a rough mold is used to form a shape to some extent, and the shape is put into the recess. Once again, slightly dissolve the heat. By performing reheating in this way, it is possible to remove distortion such as twist, twist, or bend at the beginning of the injection, and to make the fluid flow again to conform to the shape in the concave portion.

Further, a resin which is cured by a change in light, temperature, or chemical composition over time is used as the resin, and a sealed space is formed between the inner peripheral surface of the concave portion and the surface of the bump formation target portion. The curing of the resin may be advanced.

[0026]

FIG. 1 is a sectional view schematically showing an example of an apparatus for forming a spacer by a spacer forming method in a touch panel according to the present invention, and FIG. FIG. In FIG. 1, the printing intaglio 1 is in the form of an endless belt as a whole, and is rotated while moving in the direction of the arrow by the right and left driving devices 4. The outermost surface of the printing intaglio 1 is shown in FIG.
As shown, it is coated with a hard, opaque, wear-resistant thin film 2 of titanium oxide or the like to form a concave portion 3 for printing. The concave portion 3 of the printing intaglio 1 which has reached the position of the squeegee 22 which has been subjected to the conductive treatment by the rotation is filled with the elastomer type ultraviolet curable resin paste 5. The concave portion 3 of the printing intaglio 1 further rotates and proceeds to the transfer process.

On the other hand, the glass plate 6 for the touch panel sent from the preceding process passes through the ultraviolet irradiation device 7 for surface modification for improving the wettability and is transferred to the transfer device 9 which moves on the table 8. It is transferred to the transfer step with the ITO coating surface 10 facing upward. The position of the glass plate 6 and the concave portion 3 of the printing intaglio 1 are measured by an image recognition device 11 located at the forefront of the transfer step, and the glass plate 6 and the concave portion 3 are brought into close contact with each other after the alignment is performed.

The elastomer-type ultraviolet-curing resin 5 filled in the concave portion 3 of the printing intaglio 1 is made of glass by a quartz glass roller 12 having a good ultraviolet transmittance and a resin-curing ultraviolet lamp 13 installed in a hollow portion inside the roller. The glass plate 6 is pressed against the surface of the plate 6 and cured while promoting adhesion.
Is fixed.

That is, in FIG. 2, the printing intaglio 1 is in close contact with the glass plate 6 for the touch panel with the ITO coating surface 10 facing upward, and the glass plate 6 side has the concave portions 3 of the printing intaglio 1. An uncured elastomer-type UV-curable resin 5 is filled therein. A pressure is applied to the uncured elastomer-type UV-curable resin 5 by a quartz glass roller 12 pressed from above the intaglio 1 for printing, and the UV-cured The adhesion of the resin 5 is promoted.

The hollow portion of the quartz glass roller 12 is irradiated with ultraviolet rays 19 from an ultraviolet lamp 13.
The ultraviolet rays 19 pass through the transparent printing intaglio 1 to cure the uncured ultraviolet curing resin 5 filled in the concave portions 3. However, since the surface of the printing intaglio 1 around the concave portion 3 is coated with the light-shielding thin film layer 2 that does not transmit ultraviolet light, the ultraviolet light 19 is applied to the ultraviolet curable resin 20 oozing around the concave portion which becomes a shadow. Not hit. Exposure is completed without curing the portion of the resin not exposed to the ultraviolet rays 19. In the panel cleaning tank 21 in the post-processing step,
The UV-curable resin 20 that has not been cured due to this bleeding can be easily removed and does not remain on the ITO-coated surface, so that it becomes an unnecessary insulating layer and impairs the function of the touch panel. Does not occur.

When the belt of the intaglio printing plate 1 further moves, it reaches the separating device 14 and the belt of the intaglio printing plate 1 and the surface of the glass plate 6 are separated therefrom. The image is transferred to the glass plate 6.

The intaglio printing plate 1 on which the transfer of the elastomer type ultraviolet curable resin 5 has been completed is passed through the driving device 4 and in the intaglio belt cleaning device 15, the uncured resin which has not been cured by bleeding out, and in particular, fine pieces of glass (cullet) ) Is removed. Further, after being rinsed with the cleaning agent in the rinsing tank 16 and dried in the drying chamber 17, a process for improving the releasability is performed by the release agent applying device 18, and the process returns to the resin paste filling step. In this way, the printing intaglio 1 circulates through a pretreatment step of applying a release agent, a squeegee filling step, a transfer step from close contact to peeling, and a post-treatment step from washing to drying, and is repeatedly printed. .

In the circulating step, the filling step is hindered by the incorporation of bubbles into the ultraviolet curable resin 5 or the intrusion of air into the concave portions in the filling step, and the peeling of the printing intaglio 1 is difficult due to atmospheric pressure in the transfer step. In order to cope with the above, it is desirable that at least the range from the filling step to the transfer step be a reduced-pressure atmosphere or a vacuum. In order to prevent static electricity during the process, it is desirable to take various antistatic measures. For example, an ionizer is used.

[0034]

According to the method and apparatus for forming a spacer in a touch panel according to the present invention, high-definition printing can be realized at low cost, without falling off from a printing material such as a panel surface, and fatigue fracture occurs. It is possible to form a highly reliable spacer or the like on a printing substrate without any trouble.

According to the touch panel of the present invention, since the spacer has elasticity, it is less likely to be broken than a spacer made of hard plastic.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing an example of an apparatus for forming a spacer by a spacer forming method in a touch panel of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a state of exposure and curing in a transfer step of a spacer forming method in the touch panel of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intaglio for printing 2 Thin film 3 Concavity for printing 4 Driving device 5 Elastomer type ultraviolet curing resin paste 6 Glass plate for touch panel 7 UV irradiation device for surface modification 8 Surface plate table 9 Transport device 10 ITO coating surface 11 Image recognition device 12 Quartz glass roller 13 Resin curing ultraviolet lamp 14 Separation device 15 Intaglio belt cleaning device 16 Rinse tank 17 Drying chamber 18 Release agent coating device 19 Ultraviolet ray 20 Ultraviolet curing resin oozing around concave part 21 Panel cleaning tank 22 Squeegee

Claims (16)

[Claims] Claims 1. A concave portion of an intaglio printing plate is filled with a resin paste, and the intaglio plate is brought into close contact with an object to be printed.
A method for forming a spacer in a touch panel, wherein a resin is transferred to a printing material by separating an intaglio and a printing material. 2. A concave portion of a printing intaglio is filled with a photocurable resin paste, the intaglio plate is brought into close contact with a printing material, and light is irradiated to cure the photocurable resin, and then the intaglio plate and the printing material are separated. A method of forming a spacer on a touch panel, wherein the photocurable resin is transferred to a print substrate. 3. The method for forming a spacer in a touch panel according to claim 1, wherein the intaglio printing plate is a plastic plate. 4. A concave portion of a printing intaglio having a light-shielding layer on the surface other than the concave portion is filled with a photocurable resin paste, and the intaglio is brought into close contact with a printing material, and light is irradiated from a surface opposite to the surface having the concave portion of the intaglio. Irradiating the photocurable resin onto the print material by curing the photocurable resin, and then separating the intaglio plate and the print material, thereby transferring the photocurable resin to the print material. 5. The method according to claim 4, wherein the intaglio printing plate is a plastic plate. 6. The method for forming a spacer in a touch panel according to claim 3, wherein the recess in the printing intaglio is a recess formed in the plastic plate by ablation processing. 7. The concave portion of the intaglio printing plate is a concave portion formed on the plastic plate by ablation using a light shielding mask layer having an opening formed on the plastic plate as a conformal mask. 6. The method for forming a spacer in a touch panel according to item 5. 8. The method for forming a spacer in a touch panel according to claim 7, wherein the light-shielding mask layer is a light-shielding layer formed on a surface other than a concave portion for shielding light for curing the photocurable resin paste. 9. After transferring the photocurable resin to the printing substrate,
9. The method for forming a spacer in a touch panel according to claim 4, wherein the uncured resin adhered to the printing material is removed by washing. 10. The photo-curable resin is an elastomer-type ultraviolet curable resin.
10. The method for forming a spacer in a touch panel according to 6, 7, 8 or 9. 11. The intaglio printing plate for printing is an endless belt-shaped intaglio, and the filling of the concave portion with the resin paste and the transfer of the resin are repeatedly performed.
The method for forming a spacer in a touch panel according to 5, 6, 7, 8, 9 or 10. 12. A method of filling a concave portion of an intaglio printing plate with a resin paste, bringing the intaglio plate into close contact with a substrate to be printed, and curing the resin, and then separating the intaglio plate and the substrate to transfer the resin to the substrate. An apparatus for forming a spacer in a touch panel, comprising: 13. A touch panel, wherein the spacer is formed of a material having elasticity. 14. The touch panel according to claim 13, wherein
12. A method for forming a spacer in a touch panel according to claim 1, wherein an elastic polymer compound paste is used as the resin paste. Touch panel. 15. A spacer material is accommodated in the mold concave portion of the mold material, and the accommodated spacer material conforms to the shape of the inner peripheral surface of the concave portion and is brought into contact with the surface of the member on which the spacer is to be formed. A method for forming a spacer in a touch panel, comprising: curing a material or, after the spacer material is cured, separating the recess from the surface of the object to be formed and transferring the cured spacer to the surface of the member to be formed. 16. The light, temperature, or
The method according to claim 1, wherein the resin is cured by a change in chemical composition over time, and the resin is cured while a closed space between the inner peripheral surface of the concave portion and the surface of the bump forming target is formed. 16. The method for forming a spacer in a touch panel according to item 15.