JP2005316619A - Touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel enabling to operate with a small operation load without breaking a glass substrate. <P>SOLUTION: The touch panel is formed by oppositely arranging an upper substrate 61 having an upper transparent electrode 63 and a pair of upper conductive electrodes 64, 65 formed on a lower surface of an upper transparent substrate 62, and a lower substrate 51 having a lower transparent electrode 53, a pair of lower conductive electrodes 54, 55, and a plurality of dot spacers 58 formed on an upper surface of a lower transparent substrate 52 with a certain clearance, and sticking the upper and lower substrates 61, 51 by a seal material 67. A glass plate of approximately 0.3-0.4 mm in thickness is used for the upper transparent substrate 62, and the seal material 67 is formed in a range of 4-6μm in thickness. The pair of upper conductive electrodes 64, 65, the pair of the lower conductive electrodes 54, 55, and the dot spacer 58 are formed to have a same thickness, and have a smaller thickness than that of the seal material 67, and an upper surface of the upper transparent substrate 62 is formed in a recessed shape to have small dents. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is arranged on a display screen such as a liquid crystal display in devices such as ATMs, car navigation systems, vending machines, copiers, and various terminals, and the user points to the information display screen according to the instructions on the fluoroscopic screen. The present invention relates to a touch panel in which data is input by directly pressing with a pen.

  The resistive film type touch panel in the prior art has an upper substrate in which a transparent electrode and a conductive electrode connected to the transparent electrode are formed on a lower surface of a flexible transparent substrate, and a transparent electrode and a conductive material connected to the transparent electrode on the upper surface. An electrode is formed, and a lower substrate having dot spacers arranged at regular intervals on the upper surface of the transparent electrode has an arrangement structure in which the transparent electrodes face each other with a predetermined gap. The touch panel is used by being arranged on the upper surface side of a display device such as a liquid crystal display device. By pressing the touch panel located in the display portion of the display device with a finger or a pen, the upper substrate of the touch panel is bent and the transparent electrode at the pressed position comes into contact with the transparent electrode on the lower substrate. The position is detected by measuring electrical resistance and the input information is read.

  The structure of a conventionally used touch panel will be described with reference to FIGS. 5 is a plan view of a conventional touch panel, FIG. 6 is a cross-sectional view taken along line EE in FIG. 5, FIG. 7 is a plan view of a lower substrate in FIG. 6, and FIG. .

  As shown in FIGS. 5, 6, 7, and 8, the conventional touch panel 20 includes a lower substrate 1 having a rectangular shape and an upper substrate 11 having flexibility. The lower substrate 1 includes a lower transparent substrate 2 made of transparent square glass, a lower transparent electrode 3 formed in a square shape on the upper surface of the lower transparent substrate 2, and the lower transparent electrode 3 facing each other up and down in the drawing. A pair of lower conductive electrodes 4 and 5 which are connected along both sides and extend to the FPC mounting portion S surrounded by a dotted line frame at one end of the lower transparent substrate 2, and a pair formed in the vicinity of the FPC mounting portion S. Connecting electrodes 6 and 7 and dot spacers 8 arranged in a matrix on the lower transparent electrode 3. The pair of connection electrodes 6 and 7 are provided in the vicinity of the FPC attachment portion S in order to perform conductive connection to upper conductive electrodes 14 and 15 of the upper substrate 11 described later.

  The upper substrate 11 is a flexible, transparent and rectangular upper transparent substrate 12, an upper transparent electrode 13 formed in a square shape on the lower surface of the upper transparent substrate 12, and the upper transparent electrode 13. A pair of upper conductive electrodes 14 and 15 are formed so as to be connected along opposite left and right sides in the figure and extend in the direction of the FPC attachment portion S.

  Then, the upper conductive electrodes 14 and 15 of the upper substrate 11 and the lower conductive electrodes 4 and 5 of the lower substrate 1 are arranged to face each other in a square arrangement, and the upper and lower substrates 11 and 1 are sealed with a certain gap. The upper and lower substrates 11 and 1 are bonded and fixed with a material 17 and the outer peripheral areas of the upper and lower substrates 11 and 1 are circulated and sealed. Further, the upper conductive electrodes 14 and 15 provided on the upper substrate 11 are electrically bonded to the pair of connection electrodes 6 and 7 provided on the lower substrate 1 at the tip portions 14a and 15a at the locations of the connection portions B and A. It is connected through the agent and is conductive.

  In addition, a polarizing plate 18 is attached to the upper surface of the upper substrate 11 and a phase difference plate 16 is attached to the lower surface of the lower substrate 1 in order to improve the antiglare property and improve the transparency and quality display. In addition, an FPC 9 is attached to the FPC attachment portion S of the lower substrate 1 so as to be electrically connected to the outside.

  Each component part of the touch panel 20 having the above structure is as follows. Transparent glass is used for the lower transparent substrate 2 constituting the lower substrate 1. As this glass, soda glass, quartz glass, alkali glass, borosilicate glass, normal plate glass and the like can be used, and those having a thickness that does not cause warpage or the like are used. In many cases, 0.7 to 1.1 mm is selected. Since the upper transparent substrate 12 constituting the upper substrate 11 requires flexibility, a transparent thin glass or a transparent plastic film is used. In general, glass is used for equipment that requires heat resistance (for example, car navigation systems). As the glass, micro glass (micro sheet glass) such as 0.2 mm-thick borosilicate glass which is strong in heat resistance and impact resistance and has flexibility is used.

  The lower transparent electrode 3 constituting the lower substrate 1 and the upper transparent electrode 13 constituting the upper substrate 11 are tin-doped indium oxide ITO (Indium Tin Oxide) films, which are vacuum deposition, sputtering, CVD, and printing. Etc. Since the lower transparent electrode 3 and the upper transparent electrode 13 are required to have a high resistance value, they are formed very thin in the range of 250 to 500 angstroms. This ITO film is formed on the entire surface of the substrate by removing unnecessary portions by photolithography and leaving necessary portions.

  The lower conductive electrodes 4 and 5 constituting the lower substrate 1, the connection electrodes 6 and 7, and the upper conductive electrodes 14 and 15 constituting the upper substrate 11 are provided for applying a voltage to the lower transparent electrode 3 and the upper transparent electrode 13. Therefore, a conductive adhesive ink formed by mixing a highly conductive metal powder such as silver powder or copper powder with a thermosetting epoxy resin or the like is formed by a printing method such as screen printing. In view of the performance of the touch panel, the lower the resistance value of these electrodes, the better. In general, the sheet resistance value of these electrodes needs to be 1/100 or less of the sheet resistance value of the transparent electrode. It is said that. Therefore, a design has been made to reduce the resistance value by increasing the thickness of printing of these electrodes or increasing the width.

  The dot spacer 8 that constitutes the lower substrate 1 is provided so that the transparent electrodes in the portions other than the pressed portion do not come into contact with each other or in order to improve the releasability between the transparent electrodes after the contact. Epoxy resin, urethane resin, and other transparent resin materials are formed in a dot matrix at regular intervals by a method such as screen printing, and then subjected to curing treatment with heat or ultraviolet rays. Since the dot spacer 8 is required to be invisible, the dot spacer 8 is designed to have a diameter of 30 to 60 μm and a dot interval of 1 to 8 mm. The thickness varies depending on the material of the upper transparent substrate 12 to be used and the gap amount between the upper and lower substrates 11 and 1, but 0.2 mm of micro glass is used for the upper transparent substrate 12, and the gap amount between the upper and lower substrates 11 and 1. Is set to approximately 10 μm, the thickness is approximately 2 to 5 μm.

  The sealing material 17 is formed by printing a thermosetting epoxy resin adhesive or acrylic resin adhesive in which spacer balls are dispersed by a method such as screen printing. The spacer balls used here are provided in order to keep the gap between the upper substrate 11 and the lower substrate 1 at a constant gap, and an insulating plastic ball or fiber glass having a predetermined size is used. The size of this plastic ball or fiber glass varies depending on the material and thickness of the transparent substrate 12 of the upper substrate 11, but when a 0.2 mm micro glass is used, one having a diameter of approximately 10 μm is selected. After this sealant 17 is printed on either the upper substrate 11 or the lower substrate 1, the upper substrate 11 and the lower substrate 1 are aligned and bonded, subjected to heat treatment under pressure and cured, Adhesive fixing is performed. In addition, the sealing material 17 has a role of fixing the upper substrate 11 and the lower substrate 1 and also has a role of a seal for preventing moisture and dust from entering inside.

  The polarizing plate 18 and the retardation plate 16 are provided in order to improve the anti-glare property and improve the transparency and display quality. Various polarizing plates 18 are used. For example, a polarizing film having a thickness of 20 μm is formed by uniaxially stretching a polyvinyl alcohol film by a conventional method, and a thickness of 80 μm is formed on both sides thereof. A polarizing plate having a thickness of 180 μm can be used by laminating the cellulose-based film. The phase difference plate 16 is made of polycarbonate and has a thickness of about 80 μm.

  A touch panel having a configuration using 0.2 mm micro glass as the upper transparent substrate has a problem that damage such as cracking is likely to occur due to impact because the glass is thin. In terms of material cost, it has a problem that it is 2.2 to 2.3 times higher than that of a glass plate having a thickness of 0.4 mm. For this reason, touch panels using a glass plate thickness of 0.3 mm or 0.4 mm have been developed. One of them is the technique disclosed in Patent Document 1 shown below.

JP 2002-215331 A

  FIG. 9 shows a cross-sectional view of the main part of the touch panel disclosed in Patent Document 1. In FIG. 9, this touch panel 30 shows a touch panel for car navigation. The upper glass substrate 21a uses 0.4 mm thick lead borosilicate glass, and the lower glass substrate 21b uses 1.1 mm thick lead borosilicate glass. doing. A pair of wiring portions 24 are connected to two opposing sides of a rectangular transparent conductive film 22a formed on the lower surface of the upper glass substrate 21a. The pair of wiring portions 24 are connected to the lower glass substrate via the transfer portion 26. It is connected to a pair of wiring branch portions 25a and 25c provided in 21b. Reference numeral 23 denotes a seal portion that seals the outer peripheral areas of the upper and lower glass substrates 21a and 21b over one circumference. Reference numeral 28 denotes a space portion between the upper and lower glass substrates 21a and 21b. The upper glass substrate 21a is curved in a convex shape and the space at the center is widened.

  10A is an enlarged cross-sectional view of the transfer portion of the touch panel in FIG. 9, and FIG. 10B is an enlarged cross-sectional view of the seal portion of the touch panel in FIG. As shown in FIG. 10A, the transfer portion 26 is formed by forming a metal film 26b on the surface of the resin particle 26a, and is formed using a dispenser mixed with a holding body 29 made of the same material as the seal portion 23. And between the pair of wiring portions 24 and the pair of wiring branch portions 25a and 25c. Further, as shown in FIG. 10B, the seal portion 23 is made of a thermosetting epoxy resin, and is mixed with spacer particles 27 such as silica spacers and glass fibers having a diameter of about 3 μm.

  Then, as shown in FIG. 10A, the integrated thickness of the transfer portion 26, the wiring portion 24, and the wiring branch portion 25a (25c) is t1, and the thickness shown in FIG. Thus, when the thickness t2 of the seal portion 23 is set, by setting t1> t2, the touch panel 30 shown in FIG. 9 has a thickness of the seal portion 23 of 3 μm, and the maximum gap between the upper and lower glass substrates 21a and 21b is 10 μm. It is supposed to be.

  Thus, by setting t1> t2, the upper glass substrate 21a is curved in a convex shape and a space 28 having a wide gap at the center is obtained, and the occurrence of Newton rings can be prevented. Yes.

In Patent Document 1, the thickness of the seal portion is also set to 8 μm or less, or 5 μm or less, the thickness of the upper glass substrate is 2 mm to 4 mm, or 3 mm to 4 mm, and the Young's modulus of the glass substrate is It is said that it is 730000 Kgf / cm ² or more and 730000 Kgf / cm ² or less. And it is supposed that the touch panel excellent in water resistance and moisture resistance is obtained while the operating load in the range of 20-200 gf is obtained by this.

  However, the touch panel having such a configuration requires a large operating load in the vicinity of the seal portion, and the operating load becomes smaller toward the center. And there exists a problem that the width | variety of Min and Max of an operating load becomes large.

  Moreover, although the technique in the cited document 1 is a technique that does not consider dot spacers at all, generally, in a touch panel having a configuration in which dot spacers are arranged in a matrix on a transparent conductive film of a lower glass substrate, Since the thickness of the dot spacer and the formation pitch interval directly affect the amount of bending of the upper glass substrate, a larger operating load is required. That is, there is a problem that an operating load exceeding a specified value is required in the vicinity of the seal portion, and a problem that an active area (an effective area of the touch area) has to be narrowed arises.

  The present invention has been made in view of the above-described problems, and aims to contain an operating load within a specified load, to suppress variations in the load, and to widen an active area.

  As a means for solving the above-mentioned problem, the invention according to claim 1 of the present invention is characterized in that a rectangular upper transparent electrode is connected to the lower surface of the upper transparent substrate and a pair of upper conductive electrodes connected to opposite sides of the upper transparent electrode. An upper substrate provided with electrodes, a rectangular lower transparent electrode on the upper surface of the lower transparent substrate, a pair of lower conductive electrodes connected to opposite sides of the lower transparent electrode and routed to the FPC mounting position, and the lower transparent electrode A plurality of dot spacers formed and a lower substrate provided with a connection electrode formed near the FPC mounting position and connected to a pair of upper conductive electrodes on the upper substrate are arranged facing each other with a certain gap, and a sealing material is used. A touch panel formed by laminating outer peripheral areas of the upper and lower substrates, wherein a glass material having a thickness of approximately 0.3 to approximately 0.4 mm is used for the upper transparent substrate, and a thickness of the sealing material is in a range of 4 to 6 μm. In the touch panel formed in A pair of upper conductive electrodes and a pair of lower conductive electrodes and the dot spacer are formed with the same thickness and thinner than the thickness of the sealing material, and the upper surface of the upper transparent substrate is concave and has a slight depression. It is characterized by that.

  According to a second aspect of the present invention, the pair of upper conductive electrodes, the pair of lower conductive electrodes, and the dot spacer are formed to a thickness of 2 to 4 μm.

  The invention according to claim 3 of the present invention is characterized in that a gap between the upper transparent substrate and the lower transparent substrate is at least 1.5 to 2 μm or more.

  The invention according to claim 4 of the present invention is characterized in that a surface having a depression on the upper surface of the upper transparent substrate is a flat surface.

  The invention according to claim 5 of the present invention is characterized in that the plurality of dot spacers are provided in a matrix at a constant pitch interval within a range of 12 to 15 mm. Is.

  As an effect of the invention, under the invention according to claim 1, the thickness of the sealing material is equal to the thickness of the pair of upper conductive electrodes and the pair of lower conductive electrodes and the dot spacers under the sealing material of 4 to 6 μm. It is made thinner. By forming it thinner than the thickness of the sealing material, it becomes possible to have a concave recess on the upper surface of the upper transparent substrate. If the upper transparent substrate has a concave recess, the gap between the upper transparent substrate and the lower transparent substrate is reduced, and the operation can be performed with a relatively low pressing operation load. Moreover, the variation in the operating load can be suppressed to a small level. In addition, as described in claim 3, the generation of Newton rings is prevented by providing a gap of 1.5 to 2 μm or more between the upper transparent substrate and the lower transparent substrate. Furthermore, by forming the same thickness, the recessed surface of the upper surface of the upper transparent substrate can be finished into a flat surface as described in claim 4. Thereby, the dispersion | variation in a press action load can be suppressed small.

  According to the second aspect of the present invention, the thickness of the pair of upper conductive electrodes, the pair of lower conductive electrodes, and the dot spacer is 2 to 4 μm. The thickness of the upper transparent substrate is optimized with this thickness. When the thickness is less than 2 μm, a gap between the upper transparent substrate and the lower transparent substrate that is smaller than 1.5 to 2 μm appears, and Newton rings are likely to occur. On the other hand, if it is thicker than 4 μm, a large pressing operating load is required, which causes a variation in the operating load.

  According to the fifth aspect of the present invention, the pitch width of the dot spacer is set to 12 to 15 mm. If it is narrower than 12 mm, a large pressing operation load is required, and the pressing operation within the allowable load becomes difficult. On the other hand, if it is wider than 15 mm, the accuracy of linearity is affected.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional view of a main part of a touch panel according to an embodiment of the present invention. FIG. 2 is an explanatory view for explaining a method of pasting the touch panel of the present invention using a pressurizing device, FIG. 3 is a perspective view of a slip sheet used in the pressurizing device, and FIG. 4 is a state of a portion D in FIG. FIG. 4A is a schematic cross-sectional view of the touch panel in a state before pressurization, and FIG. 4B is a schematic cross-sectional view of the touch panel in a state after pressure firing. .

  As shown in FIG. 1, the touch panel 50 according to the present embodiment has an upper substrate 61 and a lower substrate 51 arranged opposite to each other, seals around the outer peripheral area of the upper and lower substrates 61 and 51 with a sealing material 67 with a certain gap. doing. Further, in order to improve the antiglare property and improve the transparency and quality display, a polarizing plate 68 is attached to the upper surface of the upper substrate 61 and a retardation plate 66 is attached to the lower surface of the lower substrate 51.

  The upper substrate 61 includes a transparent and rectangular upper transparent substrate 62, an upper transparent electrode 63 formed in a rectangular shape on the lower surface of the upper transparent substrate 62, and both opposing sides of the upper transparent electrode 63. It is composed of a pair of upper conductive electrodes 64 and 65 that are connected. The lower substrate 51 includes a lower transparent substrate 52 made of transparent rectangular glass, a lower transparent electrode 53 formed in a square shape on the upper surface of the lower transparent substrate 52, and both opposing sides of the lower transparent electrode 53. A pair of lower conductive electrodes 54 and 55 formed in connection with each other, a dot spacer 58 disposed in a matrix on the lower transparent electrode 53, and a pair of connection electrodes formed in the vicinity of the FPC attachment portion S (not shown). It consists of and.

  Here, in the present embodiment, the upper transparent substrate 62 uses a 0.4 mm soda glass plate and has flexibility. The lower transparent substrate 52 uses a 1.1 mm soda glass plate. The upper transparent substrate 62 and the lower transparent substrate 52 are not particularly limited to soda glass plates, but may be glass plates of other materials, but it is preferable to use the same thermal expansion coefficient, and the same material. It is good to use. The upper transparent electrode 63 and the lower transparent electrode 53 are formed from an ITO film having a thickness of 250 to 500 mm, and are finished to the same specifications as the upper transparent electrode and the lower transparent electrode used in the prior art. A pair of upper conductive electrodes 64 and 65 connected and formed along opposite sides of the upper transparent electrode 63 and a pair of lower conductive electrodes 54 and 55 connected and formed along opposite sides of the lower transparent electrode 53 are conventionally known. Like technology, it is formed by printing methods such as screen printing using conductive adhesive ink formed by mixing highly conductive metal powder such as silver powder and copper powder with thermosetting epoxy resin, etc., and heat curing After that, or after curing about 90%, the roller is rolled with precision finishing while heating to about 100 ° C. to form a thickness of 2 to 4 μm and a width of about 1 mm. Although not shown, the pair of connection electrodes formed in the vicinity of the FPC attachment portion S is also formed to have the same thickness, that is, a thickness of 2 to 4 μm. The dot spacers 58 arranged in a matrix on the lower transparent electrode 53 are formed by screen-printing a transparent UV curable epoxy resin adhesive using a metal plate. Then, after UV curing or about 90% curing, precision finishing roller rolling is performed to form a thickness of 2 to 4 μm and an outer shape of 30 to 60 μm. The thickness of the dot spacer 58 of 2 to 4 μm is the same as the thickness of the upper conductive electrodes 64 and 65 and the lower conductive electrodes 54 and 55. The dot spacers 58 are formed at a constant pitch interval within a range of 12 to 15 mm. If the pitch interval is smaller than 12 mm, a large pressing operation load is required, which is not preferable because it deviates from a specified operation load or increases a load variation. On the other hand, when the width is larger than 15 mm, the linearity accuracy is affected.

  Next, the sealing material 67 that surrounds and seals the outer peripheral areas of the upper and lower substrates 61 and 51 is formed to a thickness of 4 to 6 μm in the present embodiment. An ink is produced by blending silica fine particles having a particle diameter of 4 to 6 μm with a thermoplastic epoxy resin in a binder, and formed by a screen printing method. Initially, the printing dimensions are 20 to 25 μm thick and 0.4 to 0.5 mm wide, and heated to 80 ° C. for 20 to 30 minutes to be semi-cured and aligned. The upper and lower substrates 61 and 51 are bonded together.

  The laminating method is performed using a pressurizing apparatus shown in FIG. As shown in FIG. 2, the pressure device 100 includes a frame 101, a flat mounting table 102, a bag-like silicon rubber 103, and a push plate 104. The method of laminating is 10 to 20 pairs of touch panels 50a to be pasted on the mounting table 102, and a laminated rubber sheet sandwiched between 10 to 20 pairs of elastic interleaving paper 105 to form a bag. By injecting gas into the interior of the 103, the silicon rubber 103 expands to pressurize the upper and lower substrates 51 and 61.

  As shown in FIG. 3, the interleaf sheet 105 is a hollow rectangular ring that matches the outer peripheral shape of the upper substrate 61. The ring width m is about 1.1 to 1.2 times larger than the width n of the sealing material 67 (the width when it is in a fully cured state).

  The pressure device 100 in which 10 to 20 sets of the touch panel 50a are set is placed in a baking apparatus with the internal gas pressure of the silicon rubber 103 being increased to about 0.06 Mpa, and the temperature is increased to about 150 ° to 160 ° C. Calcination is performed at a temperature of ˜160 ° C. for 90 to 120 minutes. 4 is an enlarged schematic view of the state of the D portion in FIG. 2, FIG. 4 (a) is a schematic cross-sectional view of the touch panel in a pre-pressing state, and FIG. 4 (b) is a state after pressure firing. The cross-sectional schematic diagram of no touch panel is shown. In FIG. 4 (a), when the sealing material 67 containing silica particles having a particle size of 5 μm is temporarily printed by printing to a width of 0.4 mm and a thickness of 25 μm, the position is aligned on the mounting table 102. The gap between the lower transparent substrate 52 and the upper transparent substrate 62 placed in this manner is 25 μm. When the interleaving paper 105 is sandwiched on the upper transparent substrate 62 and heated to 150 ° C. to 160 ° C. under pressure, the sealing material 67 is resoftened and spreads sideways as shown in FIG. A sealing material 67 having a thickness of particles, that is, a thickness of 5 μm and a width n = 2.0 mm is obtained. And it hardens | cures in the state of thickness 5micrometer and width n = 2.0mm. In addition, since the interleaf sheet 105 uses a ring width m of 1.1 to 1.2 times the width n of the sealing material, the upper transparent substrate 62 pressed by the interleaf sheet 105 is used. The pressing width is 2.2 to 2.4 mm, and the upper transparent substrate 62 is pressed by 0.2 to 0.4 mm further inside than the width n = 2.0 mm of the sealing material 67. For this reason, the upper transparent substrate 62 is warped toward the lower transparent substrate 52, and a concave portion is generated on the upper surface 62a of the portion of the upper transparent substrate 62 that is removed from the sealing material 67. The lower conductive electrodes 54 and 55 and the dot spacer 58 are formed to have the same thickness and smaller than the thickness of the sealing material 67. If it is formed to a thickness of 3 μm, a step of 2 μm is created between the sealing material 67 having a thickness of 5 μm, the lower conductive electrodes 54 and 55, and the dot spacer 58. The upper transparent substrate 62 is warped toward the lower transparent substrate 52 by the pressurization, but even in a greatly warped state, the upper transparent substrate 62 comes into contact with the lower conductive electrodes 54 and 55 and the dot spacer 58, so that it is warped only by the level difference. That is, when the step is 2 μm, the warp is generated at a maximum of 2 μm. This warpage amount can be displayed as the depression amount t shown in FIG.

  As described above, in the present invention, the thickness of the sealing material 67 is formed to 4 to 6 μm, and the thickness of the lower conductive electrodes 54 and 55 and the dot spacer 58 is smaller than the thickness of the sealing material 67. Form. Similarly, the upper conductive electrodes 64 and 65 are formed smaller than the thickness of the sealing material 67. As a result, the upper transparent substrate 62 warps toward the lower transparent substrate 52, and a concave recess is generated on the upper surface 62 a of the upper transparent substrate 62 that is removed from the sealing material 67. In FIG. 1, the upper surface 62a of the upper transparent substrate 62 is recessed and recessed, so that the gap h between the upper transparent substrate 62 and the lower transparent substrate 52 is smaller than the thickness of the sealing material 67. It is preferably 1.5 to 2.0 μm or more. This is because Newton rings are likely to occur when the gap h is smaller than this value. Moreover, since the upper surface 62a of the upper transparent substrate 62 becomes concave and is recessed, the gap between the upper transparent substrate 62 and the lower transparent substrate 52 is reduced. Therefore, a rigid glass with a thickness of 0.4 mm is applied to the upper transparent substrate 62. Even if it is used, the pressing operation load can be operated with a relatively small load. In addition, the variation in operating load can be suppressed to a small level. Further, even in the vicinity of the lower conductive electrodes 54 and 55 and the upper conductive electrodes 64 and 65, the operation area can be operated with a relatively small operation load, so that the active area is close to the lower conductive electrodes 54 and 55 and the upper conductive electrodes 64 and 65. Can spread.

  In the present invention, the lower conductive electrodes 54 and 55, the upper conductive electrodes 64 and 65, and the dot spacer 58 are formed to have the same thickness. By forming them to the same thickness, the amount of depression on the upper surface 62a of the upper transparent substrate 62 can be made uniform, and a uniform and flat depression surface can be obtained. This makes it possible to reduce the variation in operating load, and at the same time, produces an effect of suppressing the occurrence of Newton rings. In the present invention, the thicknesses of the lower conductive electrodes 54 and 55, the upper conductive electrodes 64 and 65, and the dot spacer 58 are set to 2 to 4 μm. If it is thinner than 2 μm, a gap between the upper transparent substrate 62 and the lower transparent substrate 52 that is smaller than 1.5 to 2 μm appears, and Newton rings are likely to occur. On the other hand, if it is thicker than 4 μm, a large pressing operation load is required, and there are cases where the load does not fall within the specified load. Moreover, it becomes a factor which the dispersion | variation in an operating load becomes large.

  In the present embodiment, a 0.4 mm thick glass plate is used for the upper transparent substrate 62, but the same effect can be obtained by using a 0.3 mm glass plate. Since a 0.3 mm thick glass plate is less rigid than a 0.4 mm glass plate, it is easier to operate under smaller operating loads. In addition, since the rigidity is stronger than the 0.2 mm glass plate, it can be used for a long period of time with less damage such as cracking.

  As described above in detail, in a touch panel that uses an upper transparent substrate with a thickness of 0.3 to 0.4 mm and seals with a thickness of 4 to 6 μm, the lower conductive electrodes 54 and 55 and the upper conductive electrodes 64 and 65 are used. In addition, the dot spacer 58 is formed to have the same thickness of 2 to 4 μm, and a gap between the upper transparent substrate 62 and the lower transparent substrate 52 of at least 1.5 to 2.0 μm is secured, and the pitch of the dot spacers By forming the interval at a constant pitch interval within a range of 12 to 15 mm, a touch operation can be performed under a pressing operation load sufficiently within a specified range, and a load variation state can be suppressed to a small level. In addition, it is possible to obtain a touch panel that is excellent in quality by preventing the occurrence of Newton rings and has good durability.

It is principal part sectional drawing of the touchscreen which concerns on embodiment of this invention. It is explanatory drawing explaining the method of bonding the touch panel of this invention using a pressurization apparatus. It is a perspective view of the slip sheet used in a pressurizing apparatus. FIG. 4A is a schematic diagram showing an enlarged state of a portion D in FIG. 2, FIG. 4A is a schematic cross-sectional view of the touch panel in a pre-pressing state, and FIG. 4B is a touch panel in a state after pressure firing. It is a cross-sectional schematic diagram. It is a top view of the touch panel in a prior art. It is EE sectional drawing in FIG. It is a top view of the lower board | substrate in FIG. It is a top view of the upper board | substrate in FIG. It is principal part sectional drawing of the touch panel as shown by patent document 1. FIG. 10A is an enlarged cross-sectional view of the transfer portion of the touch panel in FIG. 9, and FIG. 10B is an enlarged cross-sectional view of the seal portion of the touch panel in FIG.

Explanation of symbols

50 touch panel 51 lower substrate 52 lower transparent substrate 53 lower transparent electrodes 54 and 55 lower conductive electrode 58 dot spacer 61 upper substrate 62 upper transparent substrate 63 upper transparent electrodes 64 and 65 upper conductive electrode 66 phase difference plate 67 sealing material 68 polarizing plate

Claims (5)

An upper substrate provided with a rectangular upper transparent electrode and a pair of upper conductive electrodes connected to opposite sides of the upper transparent electrode on the lower surface of the upper transparent substrate, and a rectangular lower transparent electrode and the lower electrode on the upper surface of the lower transparent substrate A pair of lower conductive electrodes connected to opposite sides of the transparent electrode and routed to the FPC mounting position, a plurality of dot spacers formed on the lower transparent electrode, and a pair of upper conductive electrodes on the upper substrate, and close to the FPC mounting position The touch panel is formed by placing the lower substrate provided with the connection electrode and the lower substrate facing each other with a certain gap, and bonding the outer peripheral area of the upper and lower substrates with a sealing material, which is substantially the same as the upper transparent substrate. In the touch panel in which a glass plate having a thickness of 0.3 to about 0.4 mm is used and the thickness of the sealing material is in the range of 4 to 6 μm, the pair of upper conductive electrodes and the pair of lower conductive electrodes are the same as the dot spacers. The thickness of Touch panel, wherein the sealing member is formed thin than the thickness of, and has a slightly recess the upper surface of the upper transparent substrate becomes concave. The touch panel according to claim 1, wherein the pair of upper conductive electrodes, the pair of lower conductive electrodes, and the dot spacer are formed to a thickness of 2 to 4 μm. The touch panel according to claim 1 or 2, wherein a gap between the upper transparent substrate and the lower transparent substrate is at least 1.5 to 2 µm or more. The touch panel according to any one of claims 1 to 3, wherein the upper transparent substrate has a flat surface with a recess on the upper surface. 5. The touch panel according to claim 1, wherein the plurality of dot spacers are provided in a matrix at a constant pitch interval within a pitch interval of 12 to 15 mm.

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