JP2006048548A - Touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel realizing uniformization of a press load, and capable of preventing generation of Newton's rings. <P>SOLUTION: In this touch panel, a pair of upper and lower substrates provided with transparent electrodes and drawing electrodes are oppositely disposed with a prescribed gap, and peripheral areas of the upper and lower substrates are surrounded and joined by an insulative seal material. The drawing electrode has: an electrode part contacting with one side of the transparent electrode; wiring parts separated from the transparent electrode, and disposed along the inner circumference of the seal material; and a connection electrode part electrically connecting the wiring part and the electrode part, or the wiring parts. At least the electrode part has a nearly same vertical or lateral facing interval as the wiring part disposed outside the electrode part or the seal material. The electrode part has a first spacer member, the wiring part has a second spacer member of a particle diameter smaller than the first spacer member, and the seal material has an in-seal material spacer member of a particle diameter nearly equal to the second spacer member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a touch panel that is arranged on a screen of a liquid crystal display device and allows a user to input data by directly pressing the information display screen with a finger or a pen, and more particularly to a touch panel that does not generate a Newton ring and secures an input area. .

  A touch panel as an input switch of a liquid crystal display device is used by being disposed on a display surface of the liquid crystal display device. In this touch panel, an upper substrate composed of a transparent substrate having flexibility and a transparent electrode formed on the lower surface thereof, and a lower substrate composed of the transparent substrate and the transparent electrode formed on the upper surface thereof are separated from each other by a predetermined space. And it arrange | positions so that transparent electrodes may face, and is stuck by the sealing agent. Further, dot spacers are arranged in a matrix on the transparent electrode of the lower substrate.

  In this touch panel, the upper substrate is pressed by hand or an input means such as an input pen, and any one of the transparent electrodes on the upper substrate comes into contact with the transparent electrode on the lower substrate, whereby the two transparent electrodes are mutually energized. . Thereby, the control device reads the voltage value changed by the resistance value at that position, and reads the position coordinates in accordance with the change in potential difference. For this reason, the upper substrate on the input side of the touch panel is always pressed against the lower substrate, so that when used for a long period of time, the upper substrate deforms in the direction of contact with the lower substrate, and the insulation gradually decreases, causing malfunctions. It has become a problem to reduce the durability.

Along with this, concentric interference fringes, so-called Newton ring rings, are generated around the bent portion of the upper substrate. This Newton ring ring has a bad appearance, is uncomfortable in terms of feeling, and has been problematic in that an input operation is delayed or erroneously input. Therefore, the input side of the upper board swells slightly convexly toward the outside, or a pulling force that prevents the central area of the input board from falling into a concave shape or a slight force to bend outward is always applied. Preferably it is. In the case where the input side substrate is a resin film, such a state is particularly preferable because it is easily bent and droops. Also, in the case where the input side is made of glass that is difficult to bend, it is desirable that the vicinity of the center is slightly bulged in the sense that the pressing load between the center that is easy to bend and the peripheral part that is difficult to bend is uniform.

  As a first conventional technique in which such an input side substrate is curved in a convex shape or not deformed into a concave shape, a sealing material and an adhesive material coating dam are circulated twice to form a slightly thick inner sealing material. The example which implement | achieves convex curve by this is disclosed (for example, refer patent document 1). 10A and 10B are schematic diagrams for explaining the touch panel in the first prior art, in which FIG. 10A is a plan view seen through from the upper substrate side, and FIG. 10B is A in FIG. 10A. -A sectional drawing and FIG.10 (c) show BB sectional drawing of Fig.10 (a).

  As shown in FIG. 10, in the touch panel according to the first prior art, transparent electrodes 1A and 6A are formed on the inner surfaces of the upper substrate 1 and the lower substrate 6, respectively. Around these transparent electrodes 1A and 6A is a seal region, and an input region AR is formed inside the seal region. Each of the transparent electrodes 1A and 6A is electrically connected to the lead-out electrode 2 and the lead-out electrode 5A in the seal region located on the outermost periphery of the touch panel. The routing electrode 2 is connected to the upper and lower connection power supply electrode 5B. The upper and lower connection electrodes 5B are routed to predetermined sides of the substrate by upper and lower connection electrode wirings 5C.

  As shown in FIG. 10B, the transparent electrode 1A of the upper substrate 1, the routing electrode 5A of the lower substrate, and the upper and lower connection electrode wiring 5C are covered with the upper insulating layer 9A and the lower insulating layer 9B in the seal region, respectively. Is done. The upper insulating layer 9A and the lower insulating layer 9B are adhesively fixed by two rows of sealing materials (adhesive material application dikes) 11A and 11B constituting an adhesive layer. Further, as shown in FIG. 10C, the routing electrode 2 and the upper and lower connection electrodes 5B of the upper substrate are adhesively fixed by two rows of sealing materials (adhesive material applying dikes) 11A and 11B in the sealing region. The sealing materials (adhesive material application dikes) 11A and 11B circulate around the input region and are printed and applied to the lower substrate 6 side, each having a top, and each top touches and adheres to the upper substrate 1.

  When printing and applying the above-mentioned two rows of sealing materials (adhesive material application dikes) 11A and 11B on the long side and short side, the top height of the sealing material (adhesive material application dike) 11A that circulates on the outside circulates on the inside It is made to become lower than the top height of the sealing material (adhesive material application embankment) 11B. By using such sealing materials (adhesive material application dikes) 11A and 11B, the periphery of the upper substrate 1 is adhesively fixed to the periphery of the lower substrate 6 so that the upper substrate 1 is directed to the lower substrate 6 in the input area AR direction. Adhesive fixed with an open inclination. As a result, the upper substrate 1 is adhered to and integrated with the lower substrate 6 in a shape that protrudes upward as a whole. This prevents the upper substrate 1 from being bent and avoids the occurrence of Newton rings.

  In addition, as a second conventional example, there is an example in which the height of the routing electrode is formed slightly higher than the outermost sealing material, and the cross section of the entire upper substrate is deformed into a substantially trapezoidal shape (for example, Non-patent document 1). 11A and 11B are schematic diagrams for explaining the touch panel in the second prior art, in which FIG. 11A is a plan view seen through from the upper substrate side, and FIG. 11B is an X of FIG. 11A. -X sectional drawing. As shown in FIG. 11, the touch panel 50 is disposed so as to face a lower substrate 41 having a rectangular shape and a flexible upper substrate 51, and is bonded and integrated around the outer edge by a sealing material 17. On the upper surface of the lower substrate 41, there are formed the transparent electrode 3 and a pair of lead-out electrodes 44 and 45 that are connected and formed up to the mounting portion of the FPC 19 along both opposing sides of the transparent electrode 3. A dot spacer 48 arranged in a matrix is provided on the transparent electrode 3. Further, connection electrodes 46 and 47 are formed in the vicinity of the FPC 19 attachment portion of the lower substrate 41 for conducting conductive connection to routing electrodes 54 and 55 of the upper substrate 51 described later.

  On the lower surface of the upper substrate 51 are formed the transparent electrode 13 and a pair of lead-out electrodes 54 and 55 that are connected and formed along both opposing sides of the transparent electrode 13 and extend toward the mounting portion of the FPC 19. . Sealing material in which the routing electrodes 54, 55 and 44, 45 of the upper and lower substrates 51, 41 are arranged to face each other in a square arrangement, and the spacer balls 17c are dispersed with a gap of about 10 μm between the upper and lower substrates 51, 41. 17, the upper and lower substrates 51 and 41 are bonded and fixed. The routing electrodes 54 and 55 provided on the upper substrate 51 and the routing electrodes 44 and 45 provided on the lower substrate 41 are formed slightly thicker than the thickness of the sealing material 17. For this reason, when the upper and lower substrates 51 and 41 are bonded together, as shown in FIG. 11B, the upper substrate 51 bulges outward and has a curved shape. This prevents the inward bending of the upper substrate 51 and avoids the generation of a Newton ring ring.

JP 2002-196886 (page 2-3, FIG. 1) Japanese Patent Application No. 2003-075098 (page 3-4, FIG. 1)

  However, in the first conventional example disclosed as a countermeasure for preventing the occurrence of a Newton ring ring in a touch panel, the technology in which the upper substrate is curved in a convex shape with respect to the lower substrate makes the sealing material circulate twice. As a result, the area where input is possible decreases. Further, in a touch panel using a glass material for the upper and lower substrates, it is necessary to set the gap between the upper and lower substrates to be as small as about 10 μm, and it is difficult to overlap the lead electrode and the sealing material as in the first conventional example. However, there is a problem that the input area has to be reduced because it is necessary to place the electrode inside the double-layer sealing material.

  In order to solve such a problem of the first conventional example, in the second conventional example, the height of the routing electrodes 54, 55, 44, 45 is formed slightly higher than the outermost sealing material 17, Similarly, the cross section of the entire upper substrate 51 is curved in a substantially trapezoidal shape. However, the height of the sealing material 17 is controlled well because it is pressurized and fired by adding the spacer 17c. However, since the lead-out electrodes 54, 55, 44, and 45 are only fired of silver paste, the sealing material 17 is as high as the sealing material 17. The height cannot be controlled, and unevenness or undulation occurs depending on the location.

  On the other hand, as shown in FIG. 15, the value of the inclination angle Q of the curved surface of the upper substrate 51 is the distance b between the inner circumference of the sealing material 17 and the outer circumference of the lead-out electrode 45 arranged adjacently along the inner circumference of the sealing material 17. And the relationship between the height t of the sealing material 17 and the difference t between the heights of the routing electrodes 45. For this reason, if the distance b between the sealing material 17 and the routing electrode 45 and the difference in height t between the sealing material 17 and the routing electrode 45 vary, the curved shape of the upper substrate 51 is distorted and the non-contact failure or the pressing load increases. There is a fear.

  Therefore, even if the upper substrate 51 has a curved shape by making the height of the routing electrode larger than the height of the sealing material 17 as in the second conventional example, irregularities or undulations occur in the routing electrode as described above. As shown in FIG. 16, the curved shape is distorted, and the input point B and the contact point P do not coincide with each other, and there is a problem that the linearity is poor and the variation in the operating load is large.

  Further, since the sealing material 17 in the second conventional example is formed by printing with an epoxy ink by screen printing or the like, and then cured by pressure baking, it is crushed by pressure even when the four corners of the screen plate are substantially perpendicular. R is attached to form a substantially arc shape. On the other hand, the lead-out electrodes 45 and 54 arranged adjacent to each other along the inner periphery of the sealing material 17 are not pressurized after printing, so that the corners are kept at a substantially right angle. 12 is a partially enlarged plan view of a portion A in FIG. 13A is a sectional view taken along the line CC in FIG. 12, and FIG. 13B is a sectional view taken along the line DD in FIG. As shown in FIG. 12, the space between the sealing material 17 and the routing electrode 45 facing each other in the direction connecting the corners, that is, the inner periphery of the sealing material 17 at the corner and the inner periphery of the sealing material 17 are adjacent to each other. The value of the distance a between the arranged routing electrode 45 and the outer periphery thereof is smaller than the value of the distance b between the sealing material 17 and the routing electrode 45 facing in the lateral direction.

  As a result, the value of the inclination angle P at the corner of the substrate 51 shown in FIG. 13A is larger than the value of the inclination angle Q of the inclined surface in the lateral direction of the substrate 51 shown in FIG. The same applies to the other corners. As a result, as shown in FIG. 14, at the four corners where the inclined surfaces 51a, 51b, 51c, 51d corresponding to the four sides of the substantially truncated pyramid-shaped upper substrate 51 intersect. Corners 16a, 16b, 16c, and 16d appear on the straight line. FIG.14 (b) shows the EE cross section in Fig.14 (a). In such corner portions 16a, 16b, 16c, and 16d, the deformation strength inward increases, and the flexibility of the upper substrate 51 decreases, so the corner portions 16a, 16b, 16c, and 16d in the four corners are touch panels. As a result, the effective area decreases.

(Object of invention)
The object of the present invention has been made in view of the above-mentioned problems, and the convex curvature of the upper substrate is made uniform by eliminating the unevenness in the height direction of the routing electrode and the undulation and making the height of the routing electrode constant. In other words, the top of the upper substrate, which is curved in a convex shape, is kept in a substantially straight line, and the linearity and the pressing load are made uniform.
Further, by eliminating the corners on the straight lines generated at the four corners where the slopes corresponding to the four sides of the upper substrate intersect, it is formed into a gentle curved surface, thereby pressing the corners at the four corners of the upper substrate. The purpose of this is to alleviate the increase in the effective area at the corners.
Moreover, it is providing the touch panel which prevents generation | occurrence | production of a Newton ring ring and is excellent in durability.

  In order to achieve the above object, the touch panel of the present invention has a pair of upper and lower substrates provided with a transparent electrode and a routing electrode facing each other with a predetermined gap, and an outer peripheral area of the upper and lower substrates with an insulating sealing material. In the touch panel formed by wrapping around, the lead electrode is in contact with one side of the transparent electrode, a wiring part that is spaced from the transparent electrode and is disposed along the inner periphery of the sealing material, and the wiring part A connecting electrode part that electrically connects the electrode part or the wiring parts, and at least the electrode part and the wiring part or the sealing material arranged outside the electrode part are opposed in the vertical direction or the horizontal direction. The spacing is substantially the same, the electrode portion has a first spacer member, the wiring portion has a second spacer member having a particle size smaller than that of the first spacer member, and the sealing material is the second spacer member. Inside seal material with almost equal particle diameter It characterized by having a p o member.

  Further, the difference between the particle size of the first spacer member and the particle size of the second spacer member is set in a range of 1 to 5 μm.

  Further, the content ratio of the first spacer member contained in the electrode portion of the routing electrode and the second spacer member contained in the wiring portion of the routing electrode is set in a range of 10 to 20% by volume. It is characterized by.

  In addition, the first spacer member contained in the electrode portion of the routing electrode and the second spacer member contained in the wiring portion of the routing electrode are made of conductive particles on which a conductive film such as gold, silver, or copper is formed. It is characterized by becoming.

  Further, the sealing material is characterized in that the four corners of the inner periphery are formed at substantially right angles.

  Further, the height value of the connecting electrode of the routing electrode is set to a value smaller than the height of the sealing material.

  Further, the inclination of the upper substrate is 0.0015 to 0.006 mm per mm.

  The upper substrate is made of a glass plate.

  As described above, in the touch panel of the present invention, the first spacer member is mixed in the electrode portion of the routing electrode that is in contact with one side of the transparent electrode, and the first spacer member having a particle size smaller than that of the first spacer member is included in the wiring portion of the routing electrode. By mixing the two spacer members, unevenness and waviness in the height direction of the routing electrode can be eliminated, and the heights of the electrode portion and the wiring portion of the routing electrode can be made constant. In addition, the electrode portion of the routing electrode and the wiring portion or the sealing material disposed adjacent to the outside of the electrode portion are configured to have substantially the same distance in the vertical or horizontal direction, and the sealing agent. By setting the particle size of the spacer member in the sealing material mixed in the electrode and the particle size of the second spacer member mixed in the wiring portion of the routing electrode to substantially the same value, the vertex of the upper substrate curved in a convex shape is almost It becomes linear, and the error of linearity (linearity) can be reduced and the pressing load can be made uniform.

In addition, the electrode part of the lead electrode and the wiring part, and a connecting electrode part for electrically connecting the wiring parts are provided near the corners of the upper and lower substrates, and the height of the connecting electrode part is not mixed with a spacer member. Is set to a value lower than that of the second spacer member, thereby eliminating the straight corners generated at the four corners where the curved surfaces corresponding to the four sides of the upper substrate intersect and forming a gentle curved surface. be able to. As a result, it is possible to alleviate the increase in pressing load at the four corners of the upper substrate and to enlarge the effective area of the corners.
As a result, analog input can be performed more accurately and operability can be improved. Furthermore, it is possible to provide a touch panel that prevents the generation of a Newton ring ring and has excellent durability.

  Hereinafter, a touch panel according to an embodiment of the present invention will be described with reference to FIGS. 1A and 1B are schematic views showing a touch panel according to the present embodiment. FIG. 1A is a plan view seen through from the upper substrate side, and FIG. 1B is a cross-sectional view taken along line FF in FIG. 2 and FIG. 3 are partial enlarged views of portion A in FIG. 1, FIG. 4 is a partial enlarged view of portion B in FIG. 1, and FIG. 5 is a partial enlarged view of portion C in FIG. 6 is a plan view of the lower substrate, FIG. 7 is a plan view of the upper substrate, FIG. 8 is a partial sectional view of the routing electrode of the lower substrate, and FIG. 9 is a partial sectional view of the routing electrode of the upper substrate. The touch panel in this embodiment is characterized by the shape and arrangement of the sealing material and the routing electrode, and other basic configurations are similar to those of the prior art. Therefore, the same constituent elements as those in the prior art are given the same numbers and the description thereof is omitted.

  As shown in FIG. 1, the touch panel 40 has an upper substrate 31 and a lower substrate 41 arranged with a sealant 27 so that the transparent electrodes 3 and 13 face each other, and the peripheral portions of the upper and lower substrates 31 and 41 are arranged. It is stuck and integrated with a sealant 27 so as to maintain a constant interval. For the sealant 27, an epoxy resin adhesive or the like is selected, printed by a method such as screen printing with a width of 0.5 mm and a thickness of 30 μm, and baked in a bonding process of the upper and lower substrates to form a width of 1.5 mm and a thickness of 10 μm. Is done. Further, in this sealing agent 27, plastic balls having a particle size of 10 μm are dispersed as the spacer member 22 in the sealing material, and the peripheral portion of the upper substrate 31 and the lower substrate 41 is 10 μm with the spacer member 22. It plays the role of holding at intervals.

  The lower substrate 41 is made of a soda glass plate having a thickness of 1.1 mm as shown in FIGS. 1 and 6, and the soda glass plate is electrically connected to the transparent electrode 3 and opposite sides of the transparent electrode 3, respectively. Lead-out electrodes 24 and 25 are formed. The routing electrodes 24 and 25 are arranged along the inner periphery of the sealing agent 27, and one end thereof is gathered on one side of the lower substrate 41 and connected to the end portion of the FPC 19. The transparent electrode 3 is formed by patterning by etching an ITO film having a thickness of about 50 to 4000 angstroms by sputtering or CVD.

  Further, dot spacers 48 are arranged in a matrix on the surface of the transparent electrode 3. The dot spacer 48 has a circular shape with a size of about 30 to 40 μm and a height from the substrate of about 3 to 5 μm. Furthermore, the distance between the centers of the dot spacers 48 is set to about 4 to 5 mm. The dot spacers 48 are formed by printing an epoxy resin-based ultraviolet curable resin in a matrix and curing it by irradiating with ultraviolet rays. Further, connection electrodes 46 and 47 are formed in the vicinity of the attachment portion of the FPC 19 of the lower substrate 41 in order to perform conductive connection to routing electrodes 34 and 35 of the upper substrate 31 described later.

  The lead-out electrode 25 is connected to the electrode portion 25 a that is in contact with one side of the transparent electrode 3, wiring portions 25 b and 25 e that are separated from the transparent electrode 3 and arranged along the inner periphery of the sealing material 27, and the FPC 19. A wiring portion 25f for connecting the electrode portion 25a and the wiring portion 25b, and a connecting electrode portion 25d for electrically connecting the wiring portion 25b and the wiring portion 25e. Yes. The connecting electrode portions 25c and 25d are disposed in the vicinity of the corners of the upper and lower substrates 31 and 41. The routing electrode 24 includes an electrode portion 24 a that is in contact with a side facing the one side of the transparent electrode 3 and a wiring portion 24 b that is connected to the FPC 19.

  The lead-out electrodes 24 and 25 are formed by printing a silver paste film made of ink in which conductive metal powder such as silver powder is mixed in a thermosetting epoxy resin by screen printing or the like, and baking it at 130 ° C. for about 60 minutes. . As shown in FIG. 8A, a first spacer member 32 made of glass, resin balls, and fibers and having a particle size of 12 μm is mixed and added to the electrode portion 25a of the routing electrode 25. One spacer member 32 serves to keep the electrode portion 25a constant at a height of 12 μm. Further, since the silver paste film portion 29a of the electrode portion 25a varies in height when fired, the value of the height c of the silver paste film portion 29a in the fired state is set to the height n of the first spacer member 32. The height of the silver paste film part at the time of screen printing is adjusted so as to be in the range of 1/2 to 2/3 of the value. In the present embodiment, the height c of the silver paste film portion 29a in the fired state is formed in the range of 6 to 8 μm. Further, although not shown, the electrode portion 24a of the routing electrode 24 is formed to have a constant height of 12 μm by adding the first spacer member 32 in the same manner as the electrode portion 25a.

  Further, as shown in FIG. 8B, a second spacer member 23 made of glass, resin balls and fibers and having a particle diameter of 10 μm is mixed and added to the wiring portion 25b of the routing electrode 25. The second spacer member 23 serves to keep the wiring portion 25b constant at a height of 10 μm. Further, since the silver paste film portion 29b of the wiring portion 25b varies in height when fired, the height d of the silver paste film portion 29b in the fired state is set to the height m of the second spacer member 23. The height of the silver paste film part at the time of screen printing is adjusted so as to be in the range of 1/2 to 2/3 of the value. In the present embodiment, the silver paste film portion 29b in the fired state is formed such that the height d is in the range of 5 to 6 μm. Further, although not shown, the electrode portion 25e is formed at a constant height of 10 μm by adding the second spacer member 23 in the same manner as the electrode portion 25b.

  Note that the second spacer member 23 was not mixed in the wiring portions 24b and 25f for connection to the FPC 19, and was formed in a range of 5 to 6 μm in height. Further, the spacer member 23 is not mixed into the connecting electrode portions 25b and 25d, and the height of the sealing material 27 is set to be lower than 10 μm, and in this embodiment, it is formed in the range of 5 to 6 μm.

  Next, a method for forming the routing electrodes 24 and 25 will be described. First, the silver paste films of the connecting electrode portions 25c and 25d, the wiring portions 24b and 25f, and the connection electrodes 46 and 47 are printed and formed in a predetermined pattern by a screen printing method or the like. At this time, both end portions of the connecting electrode portions 25c and 25d are extended and disposed so as to overlap with corresponding electrode portions or wiring portions. As described above, the silver paste film is made of ink in which conductive metal powder such as silver powder is mixed in a thermosetting epoxy resin, and no spacer member is mixed therein.

  Next, a silver paste film of the wiring portions 25b and 25e is printed and formed in a predetermined pattern by a screen printing method or the like. At this time, printing is performed so that both end portions of the wiring portion 25b overlap the end portions of the connecting electrode portions 25c and 25d, respectively. Similarly, the both ends of the wiring portion 25e are printed and formed so as to overlap the end portions of the connecting electrode portion 25d and the wiring portion 25f, respectively. The size of the overlapping portion is set to a size that can be electrically connected. As described above, a second spacer member having a particle diameter of 10 μm is mixed and added to the silver paste film.

  Next, the silver paste film of the electrode portions 24a and 25a is printed and formed in a predetermined pattern by a screen printing method or the like. At this time, printing is performed so that one end of the electrode portion 25a overlaps with the end portion of the connecting electrode portion 25c. Further, it is printed and formed so that the end of the wiring part 24b overlaps a part of the electrode part 24a. The size of the overlapping portion is set to a size that can be electrically connected as described above. As described above, the first spacer member having a particle diameter of 12 μm is mixed and added to the silver paste film. Thereafter, baking is performed at 130 ° C. for about 60 minutes, and the lead electrodes 24 and 25 are formed.

  As shown in FIGS. 1 and 7, the upper substrate 31 is made of a micro glass plate made of borosilicate glass or the like with a thickness of 0.2 mm, and a transparent electrode 13 is formed on both sides of the transparent electrode 13 facing each other. Leading electrodes 34 and 35 connected to each of them are formed. One end of each of the routing electrodes 34 and 35 is extended so as to be conductively connected to connection electrodes 46 and 47 provided in the vicinity of the mounting portion of the FPC 19 of the lower substrate 41.

  The winding electrodes 34 and 35 include an electrode portion 34 a that is in contact with one side of the transparent electrode 13, and wiring portions 34 b and 35 b that are separated from the transparent electrode 13 and are disposed along the inner periphery of the sealing material 27. And a connecting electrode portion 34c that electrically connects the electrode portion 34a and the wiring portion 34b, and a connecting electrode portion 35c that electrically connects the electrode portion 35a and the wiring portion 35b.

  The lead-out electrodes 34 and 35 are formed by printing and baking by the screen printing method or the like, similarly to the lead-out electrodes 24 and 25 of the lower substrate 41 described above. As shown in FIG. 9A, a first spacer member 32 made of glass, resin balls, and fibers and having a particle diameter of 12 μm is mixed and added to the electrode portion 35a of the routing electrode 35. One spacer member 32 serves to keep the electrode portion 35a constant at a height of 12 μm. Further, since the silver paste film portion 39a of the electrode portion 35a varies in height when fired, the height c of the silver paste film portion 39a in the fired state is set to the height n of the first spacer member 32. The height of the silver paste film part at the time of screen printing is adjusted so as to be in the range of 1/2 to 2/3 of the value. In the present embodiment, the height c of the silver paste film portion 39a in the fired state is formed in the range of 6 to 8 μm. The electrode portion 34a of the lead-out electrode 34 is formed at a constant height of 12 μm by adding the first spacer member 32, as in the case of the electrode portion 35a, although not shown.

  Further, as shown in FIG. 9B, a second spacer member 23 made of glass, resin balls, and fibers and having a particle size of 10 μm is mixed and added to the wiring portion 35b of the routing electrode 35. The second spacer member 23 serves to keep the wiring portion 35b constant at a height of 10 μm. Further, since the silver paste film portion 39b of the wiring part 35b varies in height when fired, the height d of the silver paste film portion 39b in the fired state is set to the height m of the second spacer member 23. The height of the silver paste film part at the time of screen printing is adjusted so as to be in the range of 1/2 to 2/3 of the value. In the present embodiment, the silver paste film portion 39b is formed such that the height d of the silver paste film portion 39b in the fired state is in the range of 5 to 6 μm. Further, although not shown, the electrode portion 34b is formed at a constant height of 10 μm by mixing and adding the second spacer member 23, similarly to the electrode portion 35b.

  Note that the spacer member 23 is not mixed in the connecting electrode portions 34c and 35c, and the height of the sealing material 27 is set to be lower than 10 μm. In this example, it was formed in the range of 5 to 6 μm.

  The method of forming the routing electrodes 34 and 35 is the same as that of the routing electrodes 24 and 25 described above, but will be described briefly. First, the silver paste films of the connecting electrode portions 34c and 35c are printed and formed in a predetermined pattern by a screen printing method or the like. No spacer member is mixed in the silver paste film.

  Next, the silver paste film of the wiring portions 34b and 35b is printed and formed in a predetermined pattern by a screen printing method or the like. At this time, printing is performed so that one end of each of the wiring portions 34b and 35b overlaps with one end of each of the connecting electrode portions 34c and 35c. The size of the overlapping portion is set to a size that can be electrically connected. As described above, a second spacer member having a particle diameter of 10 μm is mixed and added to the silver paste film.

  Next, the silver paste film of the electrode portions 34a and 35a is printed in a predetermined pattern by a screen printing method or the like. At this time, printing is performed so that one end of each of the electrode portions 34a and 35a overlaps with the other end of each of the connecting electrode portions 34c and 35c. The size of the overlapping portion is set to a size that can be electrically connected. As described above, the first spacer member having a particle diameter of 12 μm is mixed and added to the silver paste film. Thereafter, firing is performed at 130 ° C. for about 60 minutes to form the lead electrodes 34 and 35.

  The addition ratio of the first spacer member 32 mixed and added to the electrode portions 34a, 35a, 24a, and 25a of the routing electrodes of the upper and lower substrates 31 and 41 is preferably in the range of 10 to 20% by volume. Also, the addition ratio of the first spacer member 32 mixed and added to the wiring portions 34b, 35b, 25b, 25e of the routing electrodes of the upper and lower substrates 31, 41 is preferably in the range of 10-20% by volume. This is not preferable because the conductivity of the routing electrodes 34, 35, 24, 25 of the substrates 31, 41 is hindered.

  In addition, when conductive balls on which conductive films such as gold, silver, and copper are formed are used as the first and second spacer members 32 and 23, the conductive reliability of the routing electrodes 34, 35, 24, and 25 of the upper and lower substrates 31, 41 is determined. It is more preferable in terms of sex.

  The upper and lower substrates 31 and 41 are arranged opposite to each other so that the routing electrodes 34 and 35 of the upper substrate 31 and the routing electrodes 24 and 25 of the lower substrate 41 are in a square arrangement, and are adhered with a sealant 27. The sealing material 27 is mixed with the spacer member 22 in the sealing material having a particle diameter of 10 μm so that the peripheral portions of the upper and lower substrates 31 and 41 are maintained at a constant interval of 10 μm. The first spacer member 32 having a particle size of 12 μm is mixed in the electrode portions 34 a, 35 a, 24 a, and 25 a of the routing electrodes of the upper and lower substrates 31 and 41, and the height thereof is larger than the height of 10 μm of the sealing material 27. It is formed at a constant height of 12 μm. The wiring portion 35b arranged outside the electrode portion 24a of the routing electrode, the wiring portion 25b arranged outside the electrode portion 35a of the routing electrode, and the wiring portion 25e arranged outside the wiring portion 35b have a particle size. Is mixed with a second spacer member 23 having a thickness of 10 μm and formed at a constant height of 10 μm.

  Further, a distance b between the electrode portion 34a of the routing electrode 34 of the upper substrate 31 and the sealing material 27 disposed outside the electrode portion 34a in the lateral direction, an electrode portion 25a of the routing electrode 25 of the lower substrate 41, and an electrode portion. The distance b in the longitudinal direction opposite to the sealing material 27 disposed outside of 25a, the wiring of the routing electrode 25 of the lower substrate 41 disposed outside the electrode portion 35a of the routing electrode 35 of the upper substrate 31 and the electrode portion 35a In the vertical direction between the distance b facing the portion 25b in the lateral direction and the electrode portion 24a of the routing electrode 24 of the lower substrate 41 and the wiring portion 34b of the routing electrode 34 of the upper substrate 31 disposed outside the electrode portion 24a. It arrange | positions so that the space | interval b which opposes may become substantially the same.

  Further, connecting electrodes 25 c, 25 d, 34 c are formed at a lower height than the sealing material 27 at the corners of the routing electrodes 25, 34. Further, the sealing material 27 has four corners on the inner periphery formed substantially at right angles. In this way, in order to form the inner peripheral corner 27a at a substantially right angle, when the epoxy resin adhesive is printed along the periphery of the lower substrate 41 by a method such as screen printing, the printing pattern of the epoxy resin adhesive is changed. A recess is provided at the corner of the inner periphery. By appropriately setting the size of the concave portion, the epoxy resin adhesive is crushed by heating and pressurizing in the step of bonding the upper and lower substrates 31 and 41, and the epoxy resin adhesive flows into the concave portion. As a result, the inner peripheral corner 27a of the sealing material 27 is formed at a substantially right angle.

  In this way, the inner peripheral corner 27 a of the sealing material 27 is formed at a substantially right angle, and the connecting electrodes 25 c, 25 d, 34 c provided at the corners of the routing electrodes 25, 34 are formed at a lower height than the sealing material 27. Thus, the distance between the inner circumference of the sealing material 27 related to the curved shape at the corner of the upper substrate 31 and the electrode portions of the routing electrodes 25 and 34 is set to the vertical direction or the horizontal direction between the electrode portion and the sealing material 27 or the wiring portion. It is possible to make it larger than the interval facing the direction.

  As a result, as shown in FIG. 1B, when the upper and lower substrates 31 and 41 are bonded together, the upper substrate 31 is curved outward and has a uniform shape over the entire circumference. In this method of bonding the upper and lower substrates, a frame-shaped slip sheet is placed on the outer peripheral portion of the upper surface of the upper substrate 31 and pressed. Although this utilizes the elasticity of the slip sheet, it is the same as the prior art and will not be described in detail.

  Next, the curved shape of the bonded upper substrate will be described with reference to FIGS. 2, 3, 4, and 5. 2A is a partially enlarged plan view of a portion A in FIG. 1, FIG. 2B is a sectional view taken along line GG in FIG. 2A, and FIG. 3A is a cross-sectional view taken along line JJ in FIG. Sectional drawing and FIG.3 (b) are HH sectional drawings of Fig.2 (a). 4 is a partially enlarged plan view of a portion B in FIG. 1, and FIG. 5 is a partially enlarged plan view of a portion C in FIG.

  As shown in FIG. 2A, in the portion A in FIG. 1, the sealing material 27 and the electrode portion 25a of the routing electrode 25 are arranged at a vertical interval b on one side of the substrate (upper side in the drawing). . As shown in FIG. 2B, the curved shape of the upper substrate 31 on this one side is the distance b between the electrode portion 25a of the routing electrode 25 and the sealing material 27, the height of the electrode portion 25a, and the sealing material 27. That is, it is determined by the value of the difference t between the particle diameter n of the first spacer member 32 and the particle diameter m of the spacer member 22 in the sealing material. Therefore, an appropriate value of the inclination angle Q of the curved shape in the upper substrate 31 can be obtained by appropriately setting the values of the interval b and the difference t.

  Further, on the other side of the substrate in FIG. 2A (the right side in the figure), the wiring portion 25b of the routing electrode 25 is arranged at an interval b in the horizontal direction outside the electrode portion 35a of the routing electrode 35. Further, a sealing material 27 is disposed outside the wiring portion 25b. As shown in FIG. 3A, the curved shape of the upper substrate 31 on the other side is the distance b between the electrode portion 35a of the routing electrode 35 and the wiring portion 25b of the routing electrode 25, and the height of the electrode portion 35a. And the height of the wiring portion 25 b, that is, the value of the difference t between the particle size n of the first spacer member 32 and the particle size m of the second spacer member 3.

  Therefore, the value of the inclination angle Q of the convex curved shape of the upper substrate 31 can be made substantially constant by keeping the values of the distance b and the difference t constant over the entire circumference of the upper and lower substrates. A uniform curved shape can be obtained. The difference t between the particle size n of the first spacer member 32 and the particle size m of the second spacer member 23, and the particle size n of the first spacer member 32 and the particle size m of the spacer member 22 in the sealing material. The value of the difference t is preferably set in the range of 1 to 5 μm, and is set to 2 μm in this embodiment.

  2A, a corner 27a on the inner periphery of the sealing material 27 is formed at a substantially right angle at the corner of the substrate, and a connecting electrode portion of the routing electrode 25 arranged adjacently along the inner periphery of the sealing material 27. 25c is formed in a substantially arc shape. Further, the end portion of the electrode portion 35a of the lead-out electrode 35 is disposed inside the connecting electrode portion 25c. In this corner portion, as shown in FIG. 3B, the height e of the connecting electrode portion 25c is 5 to 6 μm and the height of the sealing material 27, that is, the particle size m of the spacer member 22 in the sealing material. The value is set to a value smaller than 10 μm. For this reason, the value of the distance a between the end part of the electrode part 35a and the corner part 27a of the sealing material 27 is the distance b between the electrode part 35a of the routing electrode 35 and the wiring part 25b of the routing electrode 25 facing in the lateral direction, In addition, the distance between the sealing member 27 and the electrode portion 25a of the routing electrode 25 in the longitudinal direction is larger than the value of the interval b.

  The value of the inclination angle P at the corner of the substrate 31 is the distance a between the end of the electrode portion 35a of the routing electrode 35 and the corner 27a of the inner periphery of the sealing material 27, the height of the electrode portion 35a, and the sealing material. 27, that is, the value of the difference t between the particle diameter n of the first spacer member 32 and the particle diameter m of the spacer member 22 in the sealing material. Therefore, the value of the inclination angle P at the corner of the substrate 31 is smaller than the value of the inclination angle Q of the curved surface in the vertical direction and the horizontal direction of the substrate 31 shown in FIGS. 2 (b) and 3 (a). As a result, it is possible to eliminate the straight corners generated at the corners of the slope where the slopes corresponding to the two sides of the upper substrate 31 curved in a substantially truncated pyramid shape, and form a gentle curved surface.

  The values of the inclination angle P at the corner of the substrate 31 and the inclination angle Q of the curved surface in the horizontal and vertical directions of the substrate 31 are preferably set in the range of 0.0015 to 0.006 mm per mm. . If the value of the inclination angle Q is smaller than 0.0015 mm, the Newton ring ring is visually recognized, which is not preferable. On the other hand, if it is larger than 0.006 mm, the bending height of the upper substrate 31 becomes large and a strong pressing force is required. Therefore, by setting the value of the tilt angle Q within the above range, the touch panel can be operated with almost no force applied to the finger.

  Next, the B part of FIG. 1 is demonstrated. As shown in FIG. 4, the corner 27 a of the inner periphery of the sealing material 27 is formed at a substantially right angle at the corner of the substrate B portion, and the routing electrodes 25 and 34 disposed adjacently along the inner periphery of the sealing material 27. The end portions of the electrode portions 25a and 34a are formed in an arc shape. As a result, the value of the distance a between the corner portion 27a of the inner periphery of the sealing material 27 and the outer periphery of the end portions of the electrode portions 25a and 34a is set to the interval b facing the lateral direction between the sealing material 27 and the electrode portion 34a, and the sealing material. It becomes larger than the value of the space | interval b which opposes the vertical direction of 27 and the electrode part 25a. For this reason, the value of the inclination angle at the corner of the B part of the substrate 31 is smaller than the value of the inclination angle of the curved surface in the horizontal direction and the vertical direction of the substrate 31 as in the above-described A part. As a result, it is possible to eliminate the straight corners generated at the corners of the slope where the slopes corresponding to the two sides of the upper substrate 31 curved in a substantially truncated pyramid shape, and form a gentle curved surface.

  In the corner located diagonally to the A portion in FIG. 1, except that the routing electrode 34 is arranged with respect to the routing electrode 25 of the A portion, the rest is the same and the description is omitted. Similarly to the portion, the slope corners where the slopes corresponding to the two sides of the upper substrate 31 intersect can be formed into a gentle curved surface.

  Next, the C part of FIG. 1 is demonstrated. As shown in FIG. 5, a corner portion 27a on the inner periphery of the sealing material 27 is formed at a substantially right angle at the corner portion C of the substrate. The connecting electrode portion 25d of the routing electrode 25 arranged adjacently along the inner periphery of the sealing material 27 is formed in a substantially arc shape, and the connecting electrode portion 35c of the routing electrode 35 is formed in a substantially circular shape inside the connecting electrode portion 25d. It is formed in an arc shape. Further, the end portion of the electrode portion 24a of the lead electrode 24 is formed in a substantially arc shape inside the connecting electrode portion 35c. The height of the connecting electrodes 25d and 35c is set to a value smaller than 5 to 6 μm and the height of the sealing material 27 of 10 μm. Therefore, the value of the distance a between the end portion of the electrode portion 24a and the corner portion 27a of the sealing material 27 is the distance b between the electrode portion 35a of the routing electrode 35 and the wiring portion 25b of the routing electrode 25 facing in the lateral direction. Further, the distance b is larger than the value of the distance b between the electrode portion 24a of the routing electrode 24 and the wiring portion 35b of the routing electrode 35 facing each other in the vertical direction. As a result, the inclination angle value at the corner of the C portion becomes smaller than the inclination angle value of the curved surface in the horizontal and vertical directions of the substrate 31 as in the above-described A portion. As a result, the corner where the inclined surfaces corresponding to the two sides of the upper substrate 31 curved in a substantially truncated pyramid shape intersect with each other in the same manner as the above-described part A can be formed into a gentle curved surface.

  As described above, in the touch panel 40 according to the present embodiment, the first spacer member 32 is mixed in the electrode portions 24a, 25a, 34a, and 35a of the routing electrodes, and the second portions are connected to the wiring portions 25b, 25e, 34b, and 35b of the routing electrodes. By mixing the spacer member 23, it is possible to make the heights of the electrode part and the wiring part of the routing electrode constant by eliminating irregularities and undulations in the height direction of the routing electrode.

  Further, the electrode portions 24a, 25a, 34a, 35a of the routing electrodes, the wiring portions 25b, 34b arranged adjacent to the outside of the electrode portions 35a, 24a, and the outside of the electrode portions 25a, 34a are arranged. The spacing b facing the sealing material 27 in the vertical or horizontal direction is substantially the same, and the particle size of the spacer member 22 in the sealing material mixed in the sealing agent 27 and the wiring portion of the routing electrode The particle diameter of the mixed second spacer member 23 is set to an approximately equal value. In this way, the distance between the electrode part of the routing electrode and the wiring part or the sealing material arranged adjacent to the outside of the electrode part is set substantially the same over the entire circumference, and the electrode parts 24a, 25a, 34a, By making the height of 35a constant at 12 μm and keeping the height of the wiring portions 25b, 34b, 35b and the sealing material 27 adjacent to the outside of the electrode portion constant at 10 μm, the convexity of the upper substrate 31 is maintained. The top curve of the upper substrate 31 curved in a convex shape is almost linear, and the error in linearity (linearity) can be reduced and the pressing load can be made uniform.

  In addition, connecting electrode portions 25c, 25d, 34c, and 35c are provided near the corners of the upper and lower substrates 31, 41 to electrically connect the electrode portions and wiring portions of the electrode and the wiring portions. The spacer member is not mixed, the height is set to 5 to 6 μm, and the height of the second spacer member 23 is set to a value lower than 10 μm. It becomes smaller than the value of the inclination angle of the curved surface in the horizontal direction and the vertical direction. Thus, the straight corners generated at the four corners where the curved surfaces corresponding to the four sides of the upper substrate 31 intersect can be eliminated, and the curved shape of the upper substrate 31 can be formed into a gentle curved surface. As a result, an increase in pressing load at the four corners of the upper substrate 31 can be mitigated, and the effective area of the corners can be expanded. In addition, it is possible to realize a touch panel excellent in durability by preventing the generation of a Newton ring ring.

  In the present embodiment, an example in which a micro glass plate is used for the upper substrate has been described. However, the present invention is not limited to this, and the present invention can be applied to the case of using another glass plate or a transparent resin plate.

  In addition, the shape of the connecting electrode disposed at the corner of the lead-out electrode has been described as an example of a substantially arc shape, but is not limited thereto, and may be formed in a substantially right-angle shape.

1A and 1B are schematic views illustrating a touch panel according to an embodiment of the present invention, in which FIG. 1A is a plan view seen through from an upper substrate side, and FIG. 1B is a cross-sectional view taken along line FF in FIG. FIG. 2A is a partial enlarged view of a portion A in FIG. 1, FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along the line GG in FIG. 2A is a sectional view taken along line JJ in FIG. 2A, and FIG. 3B is a sectional view taken along line HH in FIG. 2A. FIG. 2 is a partially enlarged plan view of a portion B in FIG. 1. FIG. 2 is a partially enlarged plan view of a portion C in FIG. 1. It is a top view which shows the lower board | substrate in embodiment of this invention. It is a top view which shows the upper board | substrate in embodiment of this invention. It is a partial expanded sectional view of the routing electrode of the lower board | substrate in embodiment of this invention. It is a partial expanded sectional view of the routing electrode of the upper board in the embodiment of the present invention. FIG. 10A is a schematic diagram showing a touch panel in the first prior art, FIG. 10A is a plan view seen through from the upper substrate side, FIG. 10B is a cross-sectional view taken along line AA in FIG. ) Is a sectional view taken along line BB in FIG. FIG. 11A is a schematic view showing a touch panel according to a second conventional technique, FIG. 11A is a plan view seen through from the upper substrate side, and FIG. 11B is a cross-sectional view taken along line XX of FIG. It is a partial enlarged plan view which shows the A section in FIG. FIG. 13A is a cross-sectional view taken along the line CC in FIG. 12, and FIG. 13B is a cross-sectional view taken along the line DD in FIG. FIG. 14A is a schematic view showing a touch panel according to a second prior art, FIG. 14A is a plan view, and FIG. 14B is an EE cross-sectional view of FIG. It is a figure for demonstrating the inclination | tilt angle of the curved shape of the upper board | substrate in 2nd prior art. It is a figure which shows the deformation | transformation state of the upper board | substrate at the time of the data input of the touchscreen in a 2nd prior art.

Explanation of symbols

3, 13 Transparent electrode 19 FPC
22 Seal member spacer member 23 Second spacer member 24, 25 Leading electrode 24a, 25a Electrode portion 24b, 25b, 25e, 25f Wiring portion 25c, 25d Connecting electrode portion 27 Sealing agent 27a Corner portion 29a of inner periphery of sealing material, 29b Silver paste film portion 31 Upper substrate 32 First spacer members 34, 35 Leading electrodes 34a, 35a Electrode portions 34b, 35b Wiring portions 34c, 35c Connecting electrode portions 39a, 39b Silver paste film portions 40, 50 Touch panel 41 Lower substrate 46 47 Connecting electrode 48 Dot spacer

Claims (8)

In a touch panel in which a pair of upper and lower substrates provided with a transparent electrode and a routing electrode are arranged to face each other with a predetermined gap, and an outer peripheral region of the upper and lower substrates is joined with an insulating sealing material.
The routing electrode includes an electrode portion that is in contact with one side of the transparent electrode, a wiring portion that is spaced from the transparent electrode and is disposed along the inner periphery of the sealing material, and the wiring portion and the electrode portion or wiring. A connecting electrode part that electrically connects the parts, and at least the electrode part and a spacing facing the wiring part or the sealing material arranged outside the electrode part in the vertical or horizontal direction; Are substantially the same, the electrode portion has a first spacer member, the wiring portion has a second spacer member having a particle diameter smaller than that of the first spacer member, and the sealing material is the second spacer member. A touch panel having a spacer member in a sealing material having a particle diameter substantially equal to that of the spacer member.   The touch panel according to claim 1, wherein the difference between the particle size of the first spacer member and the particle size of the second spacer member is set in a range of 1 to 5 m.   The content ratio of the first spacer member contained in the electrode portion of the routing electrode and the second spacer member contained in the wiring portion of the routing electrode is set in a range of 10 to 20% by volume. The touch panel according to claim 1 or claim 2, wherein   The first spacer member contained in the electrode portion of the routing electrode and the second spacer member contained in the wiring portion of the routing electrode are made of conductive particles on which a conductive film such as gold, silver, or copper is formed. The touch panel according to any one of claims 1 to 3, wherein:   The touch panel as set forth in claim 1, wherein four corners of the inner periphery of the sealing material are formed at substantially right angles.   The touch panel according to claim 1, wherein a value of a height of the connecting electrode of the routing electrode is set to a value smaller than a height of the sealing material.   The touch panel as set forth in claim 1, wherein the upper substrate has an inclination of 0.0015 to 0.006 mm per 1 mm.   The touch panel as set forth in claim 1, wherein the upper substrate is made of a glass plate.

Images