JP2015095022A - Electrostatic capacitance touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic capacitance touch panel with high quality in which surface roughness of a rear surface of a resin layer for eliminating a step due to a decorative layer formed on an outer edge part of a rear surface of a transparent panel substrate is not viewed.SOLUTION: The electrostatic capacitance touch panel comprises: a flat resin layer 4 formed on inside of a step of a decorative layer 3 and a rear surface of the decorative layer 3 on a rear surface of a transparent panel substrate 2 on which the decorative layer 3 is formed and which has flexibility; and a sensor part 5 formed of transparent electrode layers 5a, 5b formed on the rear surface of the flat resin layer 4. The flat resin layer 4 has the rear surface having maximum height of 0.1 μm or less of irregularity formed by transferring to the flat surface by compression processing.

Description

  The present invention relates to a capacitive touch panel, and more particularly to a capacitive touch panel having a decorative layer formed on an outer edge portion of a back surface of a transparent panel substrate.

  Smartphones and tablet PCs that can be easily operated with a touch panel have become widespread, and thinning, lightening, and cost reduction of touch panels are urgent issues.

  There are various touch panel detection methods, for example, a resistive film method in which two resistive films are overlapped to specify a designated position, or an ultrasonic wave or surface acoustic wave is generated on the panel surface to detect the designated position. A surface acoustic wave method is exemplified. The touch panel used for the above-described smartphone or tablet PC taps or drags on the panel with a finger, or performs a pinch-out operation that spreads two fingers on the screen to enlarge the image, It is necessary to deal with a complicated and flexible operation such as a pinch-in operation that moves two fingers together. Therefore, at present, a capacitive touch panel that forms a xy matrix using transparent electrodes and can simultaneously detect a plurality of designated positions has become the mainstream.

  By the way, in a conventional image display panel such as an electronic device and a capacitive touch panel provided on the surface thereof, various designs are added to the peripheral area of the image display area as a decoration area, thereby improving the product value. Has been made. However, since the wiring pattern that is electrically connected to the transparent electrode is formed in the peripheral region, when the laminated body is configured, unevenness corresponding to the shape of the wiring pattern occurs on the surface of the touch panel. There is. In this case, there is a problem that the desired flatness of the touch panel cannot be maintained and the commercial value is impaired.

  Also, when decorating the panel substrate and pasting the optical double-sided tape on it, air bubbles or air layers may be generated inside the steps created by the decoration, so the decorative layer on the back of the panel substrate The panel substrate is formed in a smooth state without distortion by filling an ultraviolet curable resin so as to fill the level difference due to the surface and smoothing the back surface of the panel substrate (see, for example, Patent Documents 1 and 2). .

  In the disclosed technologies of Patent Documents 1 and 2, by covering the ultraviolet curable resin filled so as to fill the step by the decorative layer on the back surface of the panel substrate with a separator film, and pressurizing the separator film to the cured resin side, The back surface of the panel substrate was smoothed.

Japanese Patent No. 4640626 Japanese Patent No. 4716235

  However, in the disclosed techniques of Patent Documents 1 and 2, when pressurizing the UV curable resin through the separator film, irregularities (rippling) due to distortion of the separator film or new bubbles due to the lift of the film are generated. There were problems such as occurrence. In addition, the generated bubbles change with time and affect the quality and reliability of the product. In addition, in the image display area in the decorative layer, if there are irregularities (undulations) on the surface of the cured ultraviolet curable resin, the irregularities (undulations), that is, the surface roughness will be visually recognized. This is a factor that degrades the quality of the touch panel.

  Therefore, the present invention has been made in view of the above-described conventional situation, and the surface roughness of the back surface of the resin layer for eliminating the step due to the decorative layer formed on the outer edge portion of the back surface of the transparent panel substrate. An object of the present invention is to provide a high-quality capacitive touch panel that will not be visually recognized.

  Other objects of the present invention and specific advantages obtained by the present invention will become more apparent from the description of embodiments described below.

  In the present invention, the back surface of the resin layer for eliminating a step due to the decorative layer formed on the outer edge of the back surface of the transparent panel substrate is a flat surface having a maximum unevenness of 0.1 μm or less, thereby providing a rough surface. Is not visible.

  That is, the present invention is a capacitive touch panel having a decorative layer formed on the outer edge portion of the back surface of the transparent panel substrate, wherein the transparent panel substrate has flexibility with the decorative layer formed thereon. A flattening resin layer formed on the inside of the step of the decorative layer on the back surface and on the back surface of the decorative layer; and a transparent electrode layer formed on the back surface of the flattening resin layer. The synthetic resin layer has a back surface in which the maximum height of the unevenness to which the flat surface is transferred by the pressure treatment is 0.1 μm or less.

  In the capacitive touch panel according to the present invention, the sensor unit includes, for example, a first transparent electrode layer formed on the back surface of the planarizing resin layer and a first transparent electrode layer formed on the first transparent electrode layer. 1 transparent protective film, a transparent film adhered on the first transparent protective film and having a second transparent electrode layer formed thereon, and a second film formed on the second transparent electrode layer. It can have a transparent protective film.

  In the capacitive touch panel according to the present invention, the sensor unit includes, for example, a transparent electrode layer formed on the back surface of the planarizing resin layer and an insulating layer formed on the transparent electrode layer. It can have a jumper wiring layer and a transparent protective film formed on the jumper wiring layer.

  In the present invention, the above resin is obtained by making the back surface of the resin layer for eliminating a step due to the decorative layer formed on the outer edge portion of the back surface of the transparent panel substrate a flat surface having a maximum unevenness of 0.1 μm or less. A high-quality capacitive touch panel in which the surface roughness of the back surface of the layer is not visually recognized can be provided.

It is a figure which shows the structural example of the capacitive touch panel which concerns on this invention, (A) shows the front view of a capacitive touch panel, (B) has shown the AA 'line sectional drawing. It is process drawing which shows an example of the manufacturing procedure of the said capacitive touch panel. It is a figure which shows the structure of the top plate which comprises an electrostatic capacitance type touch panel, (A) shows the front view of the said top plate, (B) has shown the AA 'line sectional drawing. It is sectional drawing which shows typically the formation process of the top plate in the 1st process of the said manufacture procedure. It is sectional drawing which shows typically the formation process of the top plate in the 2nd process thru | or 5th process of the said manufacture procedure. It is a schematic diagram which shows the image of the bubble amount which generate | occur | produces in a level | step-difference part about the sample (Examples 1-4 and comparative example) of the top plate of the capacitive touch panel manufactured according to the said procedure, (A)-(D) Shows the image of the amount of bubbles in Examples 1 to 4, and (E) shows the image of the amount of bubbles in the comparative example. It is a figure which shows the generation | occurrence | production situation which generate | occur | produces in a level | step-difference part about the sample (Examples 1-4 and comparative example) of the said top plate, (A)-(D) shows the image of the bubble amount in Examples 1-4. , (E) shows an image of the amount of bubbles in the comparative example. It is a figure which shows typically the result of having observed the back surface of the planarization resin layer in the prior art example of the top plate formed by performing a pressurizing process so that an ultraviolet curable resin may be pressurized through a separator film. It is a figure which shows the other structural example of the capacitive touch panel which concerns on this invention, (A) shows the front view of a capacitive touch panel, (B) has shown the AA 'line sectional drawing.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. In addition, the dimension of each part in drawing shows the outline, and especially sectional drawing is taken as the dimension emphasized in the thickness direction in order to show a structure clearly.

  1A and 1B are diagrams showing a configuration example of a capacitive touch panel 100 according to the present invention, in which FIG. 1A is a front view of the capacitive touch panel 100, and FIG. Show.

  The capacitive touch panel 100 includes a transparent panel substrate 2, a decoration layer 3 formed on the outer edge of the back surface of the transparent panel substrate 2, a back surface side of the transparent resin base material 2, and a back surface side of the decoration layer 3. And a sensor plate 5 formed on the back surface of the planarizing resin layer 4 of the top plate 1. The sensor unit 5 is formed on the back surface of the first transparent electrode layer 5a and the first transparent electrode layer 5a formed on the back surface of the flattening resin layer 4, and protects the first transparent electrode layer 5a. 1 transparent protective film 6a and a transparent film 8 having a second transparent electrode layer 5b attached to the first transparent protective film 6a with a transparent adhesive 7 interposed therebetween. In order to protect the surface of the second transparent electrode layer 5b, a second transparent protective film 6b is formed on the second transparent electrode layer 5b. Wiring (not shown) drawn from the first and second transparent electrode layers 5 a and 5 b is connected to an external circuit via a flexible printed circuit board (FPC) 9.

  The flattening resin layer 4 of the top plate 1 in this capacitive touch panel 100 is a resin layer obtained by curing an ultraviolet effect resin or the like, and before the resin layer is cured in the manufacturing process as described later. The compression treatment is performed in a state where the back surface of the flattening resin layer 4 is covered with a flat substrate having a flat surface such as a glass plate, so that the flat surface of the flat substrate is the back surface of the flattening resin layer 4. The transferred irregularities have a flat surface with a maximum height of 0.1 mm or less.

  Thus, by setting the maximum height of the unevenness on the back surface of the flattening resin layer 4 to 0.1 μm or less, the surface roughness of the back surface of the flattening resin layer 4 in the image display area in the decorating layer 3. Will not be visually recognized, and the surface roughness of the back surface of the flattening resin layer 4 will not degrade the quality of the capacitive touch panel 100.

  That is, in this capacitive touch panel 100, the surface roughness of the back surface of the planarizing resin layer 4 for eliminating a step due to the decorative layer 3 formed on the outer edge portion of the back surface of the top plate 1 is visually recognized. It is a high-quality capacitive touch panel without any.

  The capacitive touch panel 100 is manufactured, for example, by performing the processes of the first to sixth steps (S1 to S6) according to the procedure shown in the process diagram of FIG.

  That is, in the first step S <b> 1, a planarizing resin is formed on the inner side of the step of the decorative layer 3 on the back surface of the flexible transparent panel substrate 2 on which the decorative layer 3 is formed and on the back surface of the decorative layer 3. A layer 4 is formed, and in the second step S2, a pressure treatment is applied to the planarizing resin layer 4 in a state where the back surface of the planarizing resin layer 4 and the planar surface of the planar substrate 30 are bonded together, In step S3, the flattened resin layer 4 subjected to the pressure treatment is further subjected to a clave treatment, and in the fourth step S4, the flattened resin layer 4 subjected to the clave treatment is cured, In step S5, the flat substrate 30 is peeled off from the hardened flattening resin layer 4, thereby forming the transparent panel substrate 2, the decorative layer 3, and the flattening resin layer 4 in FIG. B) Top plate 1 structured as shown in B) Formation to. 3A shows a front view of the top plate 1, and FIG. 3B shows a cross-sectional view taken along the line AA '.

  And the said capacitive touch panel 100 is completed by forming the sensor part 5 provided with electrode layer 5a, 5b in the back surface of the planarization resin layer 4 of the said top plate 1 in 6th process S6.

  That is, first, in the first step S1, the inside of the step of the decorative layer 3 on the back surface of the flexible transparent panel substrate 2 having the decorative layer 3 formed on the outer periphery and the back surface of the decorative layer 3 are provided. A planarizing resin layer 4 is formed.

  Specifically, in this first step S1, a transparent panel in which a decorative layer 3 is formed as shown in FIG. 4B on the back outer peripheral region of the transparent panel substrate 2 shown in FIG. An ultraviolet curable resin is printed on the entire surface of the substrate 2 on the inner side of the step of the decorative layer 3 on the back surface of the transparent panel substrate 2 and on the back surface of the decorative layer 3 as shown in FIG. By forming the planarizing resin layer 4, the top plate 1 composed of the transparent panel substrate 2, the decorative layer 3, and the planarizing resin layer 4 is formed.

  Here, the decoration layer 3 is formed on the outer edge of the liquid crystal screen that constitutes a smartphone, a tablet terminal, etc., and is visually recognized from the outside as a frame area in which an electrode, wiring, etc. necessary for functioning the touch panel are formed. It is a layer formed for the purpose of covering so that it cannot be done. The decorative layer 3 is formed by, for example, overlaying colored inks in multiple layers by silk screen printing. In order to apply a predetermined thickness so that the electrodes and wirings formed in the frame region do not pass through, it is easy to make a thick coating with a single application. It is necessary to form a multi-layered printing layer by thinning and dividing into multiple times. For example, in the case of dark ink that does not easily transmit light, a printing layer is formed by applying twice, and in the case of light color ink (such as white) that easily transmits light, it is applied approximately four times. Need to do. When the coating thickness per one time is about 8 μm, the light color ink layer has a thickness of about 32 μm.

  In the next second step S2, the flattening resin layer 4 is subjected to pressure treatment in a state where the back surface of the flattening resin layer 4 and the flat surface of the flat substrate 30 are bonded together.

  Specifically, in the second step S2, as shown in FIG. 5A, for example, a glass plate is adsorbed as a flat substrate 30 on the top plate 20 having a suction function, and the flat substrate 30 By sandwiching the top plate 1 with the roller 21 and rolling the roller 21 in the direction of the arrow, using the bonding device for bonding the flat substrate 30 and the top plate 1, the transparent panel substrate 2 side is The flattening resin layer 4 is pressed by the roller 21.

  In this way, the flattening resin layer 4 is pressed by the roller 21 from the transparent panel substrate 2 side and the flat substrate 30 is bonded to the flattening resin layer 4, whereby the flattening resin layer is bonded. 4, the flat surface of the flat substrate 30 is transferred, and the back surface of the flattening resin layer 4 is, for example, the surface accuracy of, for example, a glass plate used as the flat substrate 30, that is, the flatness and the surface roughness. And so on.

  Further, when the flattening resin layer 4 is pressed by the roller 21 from the transparent panel substrate 2 side and the flat substrate 30 is bonded to the back surface of the flattening resin layer 4, By setting the moving speed to a predetermined constant speed, it is possible to reduce bubbles remaining in the stepped portion by the decorative layer 3 of the top plate 1.

  In the next third step S3, the flattening resin layer 4 of the top plate 1 that has been subjected to the pressurizing process is further subjected to a cleaving process.

  Specifically, in the third step S3, the suction of the flat substrate 30 by the top plate 20 is stopped, the top plate 1 is separated from the top plate 20 together with the flat substrate 30, and the autoclave pressure cooker is used. Put in and cleave.

  The air bubbles remaining in the stepped portion by the decorative layer 3 of the top plate 1 that has been subjected to the pressurizing treatment can be further reduced by performing a crab treatment, and the image display area inside the decorative layer 3 Air bubbles remaining inside can be eliminated.

  Then, in the next fourth step S4, the flattening resin layer 4 of the top plate 1 that has been subjected to the clave treatment is cured.

  Specifically, in the fourth step S4, as shown in FIG. 5B, the flat substrate 30 is applied to the flattening resin layer 4 of the top plate 1 that has been subjected to the pressurizing process and the craving process. The flattening resin layer 4 is cured by irradiating ultraviolet rays from the side by an ultraviolet light source 22.

  Here, by using a transparent glass plate having a high ultraviolet transmittance for the flat substrate 20, the flattened resin layer 4 can be efficiently cured by irradiating ultraviolet rays from the flat substrate 30 side.

  The flat substrate 30 may be made of, for example, a polycarbonate base material or an acrylic resin base material through which ultraviolet rays subjected to mold release treatment pass, instead of the glass plate.

  In the next fifth step S5, the flat substrate 30 is peeled off from the cured flattening resin layer 4.

  The flat substrate 30 is made of a substrate material, for example, a glass plate having a thickness of 0.5 mm to 2 mm or less, so that the cured flattening resin layer 4 can be easily peeled off. It is preferable that the mold release process applied to the surface is performed.

  In this way, the top plate 1 having a structure as shown in FIGS. 3A and 3B is produced by the processes of the first to fifth steps (S1 to S5).

  In the next sixth step S <b> 6, the capacitive touch panel 100 is completed by forming the sensor unit 5 including the electrode layers 5 a and 5 b on the back surface of the planarizing resin layer 4 of the top plate 1.

  Specifically, as shown in FIG. 1 which is a cross-sectional view of the completed capacitive touch panel 100, in a sixth step S6, a first transparent electrode layer 5a is formed on the back surface of the planarizing resin layer 4. The first transparent protective film 6a for protecting the first transparent electrode layer 5a is formed on the back surface of the first transparent electrode layer 5a, and the transparent film 8 on which the second transparent electrode layer 5b is formed is formed on the first transparent electrode layer 5a. The second transparent protective film 6b is attached to the first transparent protective film 6a via the transparent adhesive 7 and the second transparent protective film 6b for protecting the surface of the second transparent electrode layer 5b is formed on the second transparent electrode layer 5b. The sensor unit 5 is formed in such a manner that a wiring (not shown) drawn from the first and second transparent electrode layers 5a and 5b is connected to an external circuit via a flexible printed circuit board (FPC) 9. Form.

  That is, the first transparent electrode layer 5a is formed on the back surface of the planarizing resin layer 4 using a known material. For the first transparent electrode layer 5a, a material containing Ag or Cu nanowire, ITO, ZnO or the like is preferably used. The first transparent electrode layer 5a is composed of a plurality of wirings, and is formed so as to intersect the second transparent electrode layer 5b with an insulator interposed therebetween. The first and second transparent electrode layers 5a, 5b Is formed equivalently. By directly forming the first transparent electrode layer 5a on the surface of the flattening resin layer 4, the process of sticking the transparent film on which the transparent electrode layer is formed is reduced, and the thickness is reduced by the thickness of the transparent film. Can be realized.

  The second transparent electrode layer 5b is formed on the transparent film 8, and is formed using the same material as the first transparent electrode layer 5a. Therefore, the material of the second transparent electrode layer 5b is preferably made of a material containing Ag or Cu nanowire, ITO, ZnO or the like.

  The transparent film 8 on which the second transparent electrode layer 5b is formed is adhered to the surface of the planarizing resin layer 4 on which the first transparent electrode layer 5a is formed by the transparent adhesive material 7.

  In order to adjust the linear expansion coefficient of the material for the purpose of preventing warpage of the top plate 1, it is preferable to use the same material as the transparent resin base material 2 for the transparent film 8. When using a PC resin as the material of the transparent resin substrate 2, it is preferable to use a PC resin for the transparent film 8. Since a material having a linear expansion coefficient comparable to that of PC resin may be used, for example, cycloolefin-based COC, COP resin, or the like may be used. Further, the transparent adhesive material 7 may be directly applied to the surface of the planarizing resin layer 4 on which the first transparent electrode layer 5a is formed, but in order to protect the surface of the first transparent electrode layer 5a. Alternatively, the transparent protective film 6a may be applied, and the transparent film 8 may be adhered to the entire surface of the applied transparent protective film 6a via the transparent adhesive material 7. A well-known material can be used for the 1st transparent protective film 6a, for example, a thermosetting acrylic resin and an ultraviolet curable resin coating material can be used.

  Furthermore, you may make it apply | coat the 2nd transparent protective film 6b also on the surface of the transparent film 8 in which the 2nd transparent electrode layer 5b was formed.

  Since the 1st transparent electrode layer 5a and the 2nd transparent electrode layer 5b are arrange | positioned on both sides of the 1st transparent protective film 6a, the transparent adhesive material 7, and the transparent film 8, in the 1st transparent electrode layer 5a Capacitance is formed at the intersecting position by the formed transparent electrode X and the transparent electrode Y formed on the second transparent electrode layer 5b and intersecting the transparent electrode X.

  Here, with respect to the capacitive touch panel 100 according to the above procedure, when the remaining state of bubbles generated in the stepped portion by the decorative layer 3 in the flattening resin layer 4 of the top plate 1 was confirmed, as shown in Table 1 below. Results were obtained.

  That is, in the first step S1, MRS58W, 297 × 210 × 0.8 mm manufactured by Mitsubishi Gas Chemical Co., Ltd. is used as the transparent panel substrate 2, and MRX- manufactured by Teikoku Ink Manufacturing Co., Ltd. The entire surface of the step of the decorative layer 3 on the back surface of the transparent panel substrate 2 on which the decorative layer 3 is formed by printing HF919 black and the back surface of the decorative layer 3 are printed with an ultraviolet curable resin on the entire surface. A sample of the top plate 1 (Comparative Example 1 and Example 1) formed with the top plate 1 as the fluorinated resin layer 4 and subjected to the pressure treatment in the second step S2 is prepared, and the second step A sample (Examples 2 to 4) of the top plate 1 which was subjected to the pressure treatment in S2 and further subjected to the clave treatment in the third step S3 was created, and the remaining state of the bubbles was confirmed.

  In the comparative example, in the second step S2, the maximum pressure due to rolling of the roller 21 is set to 0.5 MPa, the minimum clearance is set to 0.6 mm, and the rolling speed of the roller 21 is set to 2 m / min to perform pressure treatment. Three top plate samples were formed simultaneously.

  In Example 1, the maximum pressure due to rolling of the roller 21 is 0.5 MPa, the minimum clearance is 0.6 mm, and the rolling speed of the roller 21 is 1 m / min, which is half that of the comparative example. Three top plate samples were formed simultaneously.

  In Example 2, the maximum pressure due to the rolling of the roller 21 is 0.5 MPa, the minimum clearance is 0.6 mm, the rolling speed of the roller 21 is 1 m / min, which is half of the comparative example, and pressure treatment is performed. Further, a clave treatment was performed at 0.5 MPa and a temperature of 30 ° C. for 5 minutes to simultaneously form three top plate samples.

  In Example 3, the maximum pressure due to rolling of the roller 21 is 0.5 MPa, the minimum clearance is 0.6 mm, the rolling speed of the roller 21 is 1 m / min which is half of the comparative example, and pressure treatment is performed. Further, a clave treatment was performed at 0.7 MPa and a temperature of 30 ° C. for 5 minutes to simultaneously form three top plate samples.

  In Example 4, the maximum pressure due to the rolling of the roller 21 is 0.5 MPa, the minimum clearance is 0.4 mm, the rolling speed of the roller 21 is 1 m / min which is half of the comparative example, and pressure treatment is performed. Further, a clave treatment was performed at 0.7 MPa and a temperature of 30 ° C. for 5 minutes to simultaneously form three top plate samples.

  Here, as the area of the bubble generation region 50 in the flattening resin layer 44 of the sample 42E of the comparative example in which the three top plates 41a, 41b, and 41c are simultaneously formed, the amount of bubbles generated at the stepped portions by the decorative layers 43 6E is shown in FIG. 6E, and the bubble generation state is shown in FIG. Thus, in the sample 42E of the comparative example in which the pressure treatment was performed with the speed of the roller 21 being 2 m / min, a large amount of bubbles remained in the stepped portion by the decorative layer 43 on the upstream side in the traveling direction of the roller 21. Was.

  Moreover, while showing the image of the amount of bubbles generated in the stepped portions by the decorative layers 43 in the three top plates 41a, 41b, and 41c that are simultaneously prepared as the sample 42A of the first embodiment as shown in FIG. The state of bubble generation is shown in FIG.

  In the sample 42A of Example 1 in which the pressure treatment was performed with the speed of the roller 21 being half of 1 m / min with respect to the sample 42E of the comparative example, the remaining amount of bubbles in the stepped portion due to the decorative layer 43 is reduced. I was able to.

  In this way, by reducing the rotation speed of the roller 21 and applying pressure treatment at a constant speed over time, the remaining amount of bubbles in the stepped portion due to the decorative layer 43 can be reduced.

  Moreover, while showing the image of the amount of bubbles generated in the stepped portions by the decorative layers 43 in the three top plates 41a, 41b, and 41c, which are simultaneously created as the sample 42B of the second embodiment, as shown in FIG. The state of bubble generation is shown in FIG.

  In the sample 42B of Example 2 in which the rolling speed of the roller 21 was set to 1 m / min which is half that of the comparative example, and the clave process was further performed at 0.5 MPa, the bubbles in the stepped portion due to the decorative layer 43 The remaining amount of was less than that of the sample 42A of Example 1 above.

  As described above, the remaining amount of bubbles in the stepped portion due to the decorative layer 43 can be further reduced by subjecting the flattened resin layer 44 that has been subjected to the pressurizing process to a clave process.

  Moreover, while showing the image of the amount of bubbles generated at the stepped portions by the decorative layers 43 in the three top plates 41a, 41b, and 41c that are simultaneously created as the sample 42C of the above-described Example 3, (C) in FIG. The state of bubble generation is shown in FIG.

  In the sample 42C of Example 3 which was subjected to pressure treatment with the rolling speed of the roller 21 being 1 m / min which is half of that of the comparative example, and further subjected to craving treatment at 0.7 MPa, bubbles in the step portion due to the decorative layer 43 The remaining amount of was less than that of the sample 42B of Example 2 above.

  Thus, the residual amount of bubbles in the stepped portion due to the decorative layer 43 can be further reduced by performing the above-described craving treatment at a high pressure.

  Moreover, while showing the image of the amount of bubbles generated in the stepped portions by the decorative layers 43 in the three top plates 41a, 41b, and 41c, which are simultaneously created as the sample 42D of the fourth embodiment, as shown in FIG. The state of generation of bubbles is shown in FIG.

  The maximum pressure due to rolling of the roller 21 is 0.5 MPa, the minimum clearance is 0.4 mm, the rolling speed of the roller 21 is 1 m / min which is half of the comparative example, and pressure treatment is performed, and further at 0.7 MPa. In the sample 42D of Example 4 that was subjected to the clave treatment, the remaining amount of bubbles in the stepped portion due to the decorative layer 43 could be reduced to the same extent as the sample 42C of Example 3 above.

  As shown in (B) to (D) of FIG. 6 and (B) to (D) of FIG. 7, Example 2 in which the planarizing resin layer 44 subjected to the pressurizing treatment was further subjected to a craving treatment. In each of the samples 42B, 42C, and 42D in Example 4, the remaining amount of bubbles in the stepped portion by the decorative layer 43 can be further reduced as compared with the sample 42A in Example 1 in which only the pressure treatment is performed. The air bubbles remaining in the image display area inside the decorative layer 43 can be eliminated.

  That is, by performing a further craving process on the flattened resin layer 44 that has been subjected to the pressurizing process, bubbles remaining in the image display area inside the decorative layer 43 can be eliminated, and high quality static The capacitive touch panel 100 can be manufactured with a high yield.

  Further, the present invention was used with a surface roughness measuring machine (Forum Talysurf “PGI1250A” stylus: diamond cone stylus (cone angle = 90 °, tip diameter = 2 μm) measurement pressure: 0.75 mN) manufactured by Taylor Hobson. When the surface roughness of the back surface of the flattening resin layer 4 of the top plate 1 was measured for the capacitive touch panel manufactured by application, results as shown in Table 2 below were obtained.

  In Table 2, in the conventional example, a sample of a top plate formed by applying pressure treatment so as to pressurize an ultraviolet curable resin through a separator film is used as a conventional example. Samples 42A to 42E of the examples are examples.

  In the sample of the conventional example, when the back surface of the flattened resin layer was observed, as shown in FIG. 8, the flat portion (the undulation was 1 μm or less and the unevenness could not be visually confirmed) and the undulation portion (clearly visible). The maximum height of the flat part (difference between the minimum position and the maximum position) is about 0.712 μm, and the maximum height of the waviness part (difference between the minimum position and the maximum position) is It was about 7.803 μm to 2.796 μm.

  Note that the undulations 1, 2, and 3 of the conventional example in Table 2 are the three undulations on the sample surface shown in FIG.

  In the examples, that is, the samples 42A to 42E of the above-described examples 1 to 4 and the comparative example, the maximum height of the flat portion (difference between the minimum position and the maximum position) is about 0.071 μm without the generation of the waviness portion. Thus, it was reduced to about 1/10 of the sample of the conventional example.

  That is, in the samples 42 </ b> A to 42 </ b> E of the example, the flattening resin layer 44 is pressed by the roller 21 from the transparent panel substrate 2 side, and the flat substrate 30 is bonded to the back surface of the flattening resin layer 44. As a result, the flat surface of the flat substrate 30 is transferred to the back surface of the flattening resin layer 44, and the back surface of the flattening resin layer 44 is, for example, the surface accuracy of, for example, a glass plate used as the flat substrate 30. The flat surface has flatness and surface roughness.

  Thus, in the capacitive touch panel 100 manufactured by performing the processes of the first to sixth steps (S1 to S6), the back surface of the planarizing resin layer 4 has a maximum unevenness of 0.1 mm. Since the following flat surface is formed, the surface roughness of the back surface of the flattening resin layer 4 is not visually recognized, and the surface roughness of the back surface of the flattening resin layer 4 is the capacitance type. The quality of the touch panel 100 is not degraded.

  The transparent panel substrate 2 of the capacitive touch panel 100 is preferably formed of a polycarbonate (PC) resin that is a resin material having high heat resistance. In general, the scratch resistance of the touch panel surface is evaluated by pencil hardness (scratch hardness test, JIS K 5600), but the surface hardness of the PC resin as a single substrate is HB to H, and is scratched. Cheap. Therefore, the transparent panel substrate 2 has a transparent resin layer made of PMMA resin or the like, which is a hard resin material having high hardness, on one surface of a transparent resin base material made of PC resin or the like, that is, the surface of the capacitive touch panel 100. By forming on the side, it is possible to realize a touch panel that is not easily scratched. Furthermore, you may make it form a top coating layer as a protective layer on the surface of a transparent resin layer.

  A transparent resin base material having a transparent resin layer formed on the surface can be formed by simultaneously performing melt molding using two kinds of resin materials.

  Moreover, there is no restriction | limiting in particular as a material of the planarization resin layer 4 formed so that the whole surface may be covered over the back surface of the transparent panel board | substrate 2 and the decoration layer 3, The transparent acrylic type used for an ultraviolet curable ink Resin paints or urethane resin paints can be used. More specifically, urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, polyester urethane (meth) acrylate, polyether (meth) acrylate, polycarbonate (meth) acrylate, polycarbonate urethane (meth) acrylate It is possible to use a paint made of such as a material. The material used for the flattening resin layer 4 is more preferably one whose haze, which is the ratio of diffusely transmitted light to total light transmitted, does not exceed 1% so as not to affect the optical properties of the touch panel. As described above, when performing decorative printing with light-colored ink, the decorative layer 3 has a thickness of about 32 μm, and thus, for example, the back surface and the decorative panel of the transparent panel substrate 2 have a thickness of about 35 μm. The flattening resin layer 4 may be formed by applying an acrylic paint over the back surface of the layer 3. In order to apply the acrylic paint for forming the flattening resin layer 4, it may be applied directly using a die coater in addition to silk screen printing. Thus, since the well-known application | coating technique can be used for formation of the planarization resin layer 4, it is not necessary to introduce special equipment, and the same thing as the equipment used for the printing process of the decoration layer 3 should be used. The manufacturing cost can be reduced. When the first transparent electrode layer 5a is formed on the back surface of the flattening resin layer 4, it is possible to prevent the wiring from being cut off due to the step.

  In the above-described embodiment, the planarizing resin layer 4 that has been subjected to the pressure treatment in the second step S2 is further subjected to the craving treatment in the third step S3, and then the curing treatment in the fourth step S4. However, in the second step S2, as described above, the rotational speed of the roller 21 is slowed down and the pressure treatment is performed at a constant speed over time, so that the stepped portion by the decorative layer 3 is obtained. Therefore, depending on the specifications required for the flattening resin layer 4 of the capacitive touch panel to be manufactured, the second step S3 may be omitted in the second step S3. The planarizing resin layer 4 that has been subjected to the pressure treatment in step S2 may be directly subjected to the curing treatment in the fourth step S4.

  That is, the suction of the flat substrate 30 by the top plate 20 is stopped in the fourth step S4, and the top plate 1 in which the flattening resin layer 4 is pressed in the second step S2 is replaced with the flat substrate 30. At the same time, it may be detached from the top plate 20 and irradiated with ultraviolet rays from the flat substrate 30 side to cure the flattening resin layer 4.

  In the present embodiment, in the fifth step S5, the sensor unit 5 having a two-layer electrode structure including the electrode layers 5a and 5b formed on the back surface of the planarizing resin layer 4 of the top plate 1 is formed. However, the sensor unit 5 formed on the back surface of the planarizing resin layer 4 of the top plate 1 may not have a two-layer electrode structure. For example, a transparent electrode such as a capacitive touch panel 110 shown in FIG. A sensor portion 5A having a one-layer electrode structure including a layer 15A and a jumper wiring layer 15B having an insulating layer may be formed on the back surface of the planarizing resin layer 4 of the top plate 1. In the sensor unit 5A, a protective film 16 is formed on the back surface of the jumper wiring layer 15B in order to protect the jumper wiring layer 15B having an insulating layer, and a flexible printed circuit board 9 for connection to an external circuit is connected. The The protective film 16 may be made of a known material, and is formed, for example, by applying a thermosetting or UV curable acrylic resin.

  Here, FIG. 9 is a diagram showing a configuration of the capacitive touch panel 110A according to the present invention, (A) shows a front view of the capacitive touch panel 110A, and (B) shows a cross section taken along line AA ′. The figure is shown.

  The flattening resin layer 4 of the top plate 1 in the capacitive touch panel 110A is a resin layer obtained by curing an ultraviolet curable resin or the like, and has a flat surface such as a glass plate before the resin layer is cured. By performing the compression process in a state where the back surface of the flattening resin layer 4 is covered with the flat substrate, the back surface of the flattening resin layer 4 has the maximum height of the unevenness onto which the flat surface of the flat substrate is transferred. Is a flat surface of 0.1 mm or less.

  Thus, by setting the maximum height of the unevenness on the back surface of the flattening resin layer 4 to 0.1 μm or less, the surface roughness of the back surface of the flattening resin layer 4 in the image display area in the decorating layer 3. Will not be visually recognized, and the surface roughness of the back surface of the planarizing resin layer 4 will not degrade the quality of the capacitive touch panel 100A.

  That is, in this capacitive touch panel 100 </ b> A, the surface roughness of the back surface of the planarizing resin layer 4 for eliminating a step due to the decorative layer 3 formed on the outer edge portion of the back surface of the top plate 1 is visually recognized. It is a high-quality capacitive touch panel without any.

DESCRIPTION OF SYMBOLS 1 Top plate, 2 Transparent panel board | substrate, 3 Decorating layer, 4 Flattening resin layer, 5,5A Sensor part, 5a 1st transparent electrode layer, 5b 2nd transparent electrode layer, 6a 1st transparent protective film, 6b 2nd transparent protective film, 7 Adhesive material, 8 Transparent film, 9 Flexible printed circuit board, 10, 10A Capacitive touch panel, 15A Transparent electrode layer, 15B Jumper wiring layer, 16 Protective film, 20 Top plate, 22 Ultraviolet light Light source, 30 flat substrate, 100, 110A capacitive touch panel

Claims (3)

A capacitive touch panel having a decorative layer formed on the outer edge of the back surface of the transparent panel substrate,
A flattening resin layer formed on the inside of the step of the decorative layer on the back surface of the transparent panel substrate having flexibility on which the decorative layer is formed and on the back surface of the decorative layer;
A sensor unit comprising a transparent electrode layer formed on the back surface of the planarizing resin layer,
The said flattening resin layer is a capacitive touch panel which has the back surface which made the maximum height of the unevenness | corrugation by which the flat surface was transcribe | transferred by the pressurization process to 0.1 micrometer or less.   The sensor section includes a first transparent electrode layer formed on the back surface of the planarizing resin layer, a first transparent protective film formed on the first transparent electrode layer, and the first transparent protection layer. 2. A transparent film having a second transparent electrode layer formed on the film, and a second transparent protective film formed on the second transparent electrode layer. The capacitive touch panel described.   The sensor unit includes a transparent electrode layer formed on a back surface of the planarizing resin layer, a jumper wiring layer having an insulating layer formed on the transparent electrode layer, and a transparent formed on the jumper wiring layer. The capacitive touch panel according to claim 1, further comprising a protective film.