JP5490522B2 - Touch panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a touch panel that is arranged on a display element such as a liquid crystal or an organic EL and inputs information by a pressing operation using a finger or a pen corresponding to the display content of the display element, and a manufacturing method thereof.

  The touch panel includes a glass-glass touch panel in which an upper substrate and a lower substrate are both glass plates, and a film-glass touch panel in which the upper substrate is a film and the lower substrate is a glass plate. Since the glass-glass structure touch panel is composed of a thin glass plate on the upper substrate, there is little change over time and a high-class feeling. However, a thin glass plate is expensive, the material cost is high, and it is more expensive than a touch panel having a film-glass structure.

  First, a conventional method for manufacturing a glass-glass touch panel will be described.

  As shown in Patent Document 1, a manufacturing method is disclosed in which an upper substrate and a lower substrate are started from glass plates having an area equivalent to about 12 individual touch panels.

  As shown in FIG. 7, element sections 50 corresponding to an upper substrate and a lower substrate are formed in a matrix of 3 rows × 4 columns on each of two glass plates, and an ITO film is patterned on each element section by photoetching. The transparent electrode and the position detection electrode 58a are formed by performing the annealing.

  Next, a sealing material 51 is formed on the surface of the glass substrate on which the transparent electrode is formed by printing a sealing material on each element section 50 by a screen printing method or the like. In the seal layer 51, an opening 52 on which a seal material is not printed is formed in a part thereof, and the seal layer is also formed in the column direction from both ends thereof. All the element sections 50 are enclosed inside the inner peripheral edge of the glass substrate, and the outer peripheral seal layer 53 is formed at a predetermined interval from the seal layer 51.

  Further, in order to keep the two glass substrates at a predetermined interval, a large number of spherical dot spacers are arranged on one glass substrate. The glass substrate and the glass substrate are overlapped so that the element sections face each other, the seal layer and the outer peripheral seal layer are joined by thermosetting or the like, 12 individual touch panels are produced, and the opening is sealed with a sealing member.

  Further, a pair of bonded glass substrates are immersed and an etching process is performed on the outer surface to form a glass substrate having a desired thickness, and the adhered dirt and the like are removed by washing. Thereafter, the glass substrate is cut along the row direction cutting line 54, and each row direction element assembly is cut for each touch panel.

  However, in this manufacturing method, the process of etching the transparent electrode film formed on the glass substrate into the transparent electrode for each individual touch panel is indispensable.

  In the manufacturing method shown in Patent Document 2, as shown in FIG. 8, an ITO film is formed on a lower substrate made of a soda glass plate having a thickness of 1.1 mm, and then a pattern is formed by etching to form a transparent electrode 56. To do. A position detection electrode 58a and a lead electrode 58b that are electrically connected to the transparent electrode are formed by printing and baking a silver paste film. Further, an eaves portion including a temporary terminal 59 for connecting the routing electrode 58b and the connector 60 having the external extraction electrode 61 is formed at the lower end portion of the lower substrate.

  Next, a pattern is formed by a photolithography process on the surface of the transparent electrode 56 to form dot spacers 57.

  Thereafter, a sealant 51 for bonding the upper substrate and the lower substrate is printed on the periphery of the lower substrate, and an opening 52 for the sealant is provided in a part thereof.

  Further, a transparent electrode, a position detection electrode, and a lead-out electrode are formed on the upper substrate made of borosilicate glass having a thickness of 0.2 mm, similarly to the lower substrate. The lower end of the upper substrate is cut so as to expose the eaves of the lower substrate. Therefore, the vertical width of the upper substrate is shorter than the vertical width of the lower substrate.

  Further, the transparent electrodes of the upper substrate and the lower substrate are opposed to each other, and the upper substrate is superposed on the sealing agent 51 of the lower substrate to form upper and lower substrates, which are set on an adhesive jig and baked.

  Thereafter, the peripheral portions of the upper and lower substrates are stuck with a sealing agent 51 through a slow cooling process. The routing electrode 58b on the upper substrate is also electrically connected to the temporary terminal 59 provided on the lower substrate.

  Then, about 1.2 atmospheres of air is injected from the opening 52 of the sealing agent, the upper substrate is expanded outward, and the opening 52 of the sealing agent is sealed with the sealing member 55.

  Further, the main terminal of the connector 60 is attached to the temporary terminal 59 on the lower substrate to be electrically connected. Since a part of the temporary terminal 59 is exposed above the connector 60, it is coated with a fluororesin to prevent a short circuit.

  However, the manufacturing method described in Patent Document 2 also requires etching when forming the transparent electrode and forming the dot spacer. Further, in order to maintain a gap between the upper substrate and the lower substrate at a predetermined interval, a process of enclosing air from the opening and expanding the upper substrate outward is also necessary. Furthermore, a step of connecting the temporary terminal of the lower substrate and the main terminal of the connector and coating the exposed connection portion for moisture prevention is also necessary.

  Then, the manufacturing method of the touchscreen of the conventional film-glass structure is demonstrated.

  As shown in Patent Document 3, the touch panel uses a transparent transparent base material having flexibility for the upper substrate and a transparent insulating substrate made of a glass plate for the lower substrate.

  First, a polyethylene terephthalate film is used as the transparent insulating base material of the upper substrate, an ITO film is formed on one surface thereof, etched with an acid or the like to remove the peripheral portion of the ITO film, then cut into a sheet shape and then the upper substrate And

  Next, after using the glass plate as the transparent insulating base material of the lower substrate, after forming the ITO film and removing the peripheral portion in the same manner as the upper substrate, after forming fine dot spacers in the ITO film shape by a photo etching process Then, cut into a sheet to make a lower substrate. In addition to the glass plate, a transparent resin plate or a transparent film is used for the lower substrate.

  Furthermore, the circuit sheet uses a polyimide sheet having a thickness of 25 μm, which is formed by integrally projecting the external connection portion outside the frame by 20 mm from the main body on one side of the circuit sheet, and both sides of the circuit sheet on each side. A pair of bus bars extending in parallel and a routing circuit are formed. The bus bar and the routing circuit are formed by screen printing using a conductive paste, or by a sputtering method, a CVD method, or the like using only a metal material.

  Furthermore, the upper substrate and the lower substrate are opposed to each other with the ITO film surface therebetween, and a circuit sheet is sandwiched between them, and bonded together with an adhesive material made of double-sided tape at the periphery.

  However, in a touch panel using a transparent film having flexibility on the upper substrate, the upper substrate is likely to bend in the bonding process of the upper and lower substrates, so that the dot spacer that insulates the transparent electrode formed on the upper substrate and the lower substrate. Formation is required.

  Therefore, the touch panel disclosed in Patent Document 3 also requires etching for removing the peripheral portion of the ITO film and an etching process for forming dot spacers.

  In the touch panel described in Patent Documents 1 to 3 described above, it is apparent that the area where the upper and lower substrates are bonded and the area where the routing electrode from the position detection electrode is arranged do not overlap.

JP 2006-099247 A JP 2004-110748 A Japanese Patent Application Laid-Open No. 2004-240662

  As described above, in the touch panel structure shown in Patent Documents 1 to 3, the touch area of the touch panel is designed so that the area where the upper and lower substrates are bonded and the area where the routing electrode from the position detection electrode is arranged do not overlap. As a result, the peripheral frame area of the touch panel becomes wider, which is an obstacle to downsizing the touch panel.

  Further, as described above, the touch panel manufacturing methods disclosed in Patent Document 1 and Patent Document 2 have the following problems.

  First, in the conventional glass-glass structure touch panel manufacturing method shown in Patent Document 1, a photoetching process for forming the transparent electrodes and position detection electrodes 58a of individual touch panels on a glass plate is indispensable.

  Further, in the bonding process of the upper and lower substrates, it is necessary to align so that the position detection electrode of the upper substrate and the routing electrode of the lower substrate, or the position detection electrode of the lower substrate and the routing electrode of the upper substrate do not overlap each other, When bonding the upper and lower substrates, two steps are required: a step of attaching a sealing agent to the lower substrate and a step of placing and bonding the upper substrate so as to face the lower substrate. Furthermore, since the center part of each touch panel is heated and pressed by the bonding jig in this bonding step, the thin upper substrate is depressed on the lower substrate side. The step of closing the opening 52 after injecting air of about 1.2 atmospheres and expanding the upper substrate outward is also necessary.

  For this reason, in the conventional method for manufacturing a glass-glass touch panel, a number of steps are required in addition to the photoetching process, which increases the manufacturing cost of the glass-glass touch panel.

  On the other hand, in the conventional method for manufacturing a touch panel having a film-glass structure shown in Patent Document 3, after forming an ITO film on a roll-shaped transparent film, a process of photoetching the ITO film around the cut line with a certain width in advance, A photoetching process for forming dot spacers is essential.

  In addition, when bonding the upper and lower substrates, two steps are required: a step of providing a double-sided tape so as to expose the surface of the position detection electrode, and a step of bonding a circuit sheet between the upper and lower substrates.

  For this reason, the photoetching process is unavoidable even in the conventional method of manufacturing a touch panel having a film-glass structure, which increases the manufacturing cost.

  In this photoetching process, as shown in FIG. 9, the substrate is first cleaned and the dirt is removed and dried, then the photoresist is applied to the substrate and the surface is dried, and then the pattern is exposed and developed. Remove the unexposed photoresist layer, etch the remaining photoresist layer as a mask with a solution of hydrochloric acid and ferric chloride, and soak the remaining photoresist layer in a solution of sodium hydroxide and peel off After that, a series of many processes such as cleaning the substrate and removing chemicals and dirt are required.

  The etching equipment having these processes requires a large equipment space for flowing a large glass plate (for example, 240 mm × 380 mm), specifically, a length of about 60 m is required, and the line speed is about It takes about 180 cm / min. For this reason, in order to hold down the cost of capital investment and realize the manufacture of a touch panel with the shortest number of processes, it has been desired to establish a touch panel manufacturing method without an etching process.

The present invention has been made in view of the above-described conventional problems, and includes an upper substrate provided with a transparent electrode film on one side, a lower substrate provided with a transparent electrode film on one side, and two position detection electrodes in the X direction on one main surface. The lead electrodes are arranged so as to be opposed to each other from the position detection electrode in the X direction to the external extraction electrode, and two position detection electrodes in the Y direction are opposed to the opposite main surface, and the external extraction is performed from the position detection electrode in the Y direction. A lead electrode is routed to the electrode, a conductive paint containing metal particles is attached to the surface of the position detection electrode in the X direction and the Y direction, and the position detection electrode and the lead electrode in the X direction and the Y direction ; comprising a frame-like flexible wiring board superimposed to the formation of the insulating heat-dissolving type adhesive layer on both main surfaces and the conductive coating, through the heating dissolution type adhesive layer with the metallic particles of the conductive coating Before And X direction or the transparent electrode film of the upper substrate or the lower substrate and the position detection electrode of the Y-direction are electrically connected, wherein the heating dissolution type adhesive layer before SL on the substrate and the lower of the flexible wiring board The substrate is bonded together.

  Further, the present invention is characterized in that the conductive paint covers the entire surface of the position detection electrodes in the X direction and the Y direction, and the heat-dissolving adhesive layer covers the entire surface of the flexible wiring board.

  Furthermore, the present invention is characterized in that the conductive paint is mixed with at least silver and nickel metal particles and a binder.

  Further, a thin glass substrate is used for the upper substrate, and a glass substrate thicker than the upper substrate is used for the lower substrate.

The present invention provides a transparent electrode film on one side of two mother bases having different thicknesses, and an upper substrate having the transparent electrode film on one side substantially the same size as an individual touch panel from each of the mother bases. A step of dividing into a lower substrate, a position detection electrode and an extraction electrode in the X direction are formed on one main surface, a position detection electrode and an extraction electrode in the Y direction are formed on the opposite main surface, and the X direction and the Y direction A conductive paint containing metal particles is attached to the surface of the position detection electrode, and an insulating heat-dissolving adhesive layer is superposed on the position detection electrode and the extraction electrode in the X direction and the Y direction and the conductive paint. preparing a frame-like flexible wiring board formed on both main surfaces, heating and pressing by placing a flexible wiring board between the lower substrate and the upper substrate, the heating dissolution type adhesive of the flexible wiring board Layer Fusion to perform bonding of the lower base plate and the substrate, the X direction or the position detection electrodes of the Y direction of the metal particles contained in the conductive coating at the same time passed through the heating dissolution type adhesive layer And the step of electrically connecting the transparent electrode film of the upper substrate or the lower substrate to each other.

  Further, the present invention is characterized in that the mother base material uses glass plates having different thicknesses and is set to a size that is approximately an integral multiple of the size of the upper substrate or the lower substrate.

Further, according to the present invention, a flexible wiring board is disposed between the upper substrate and the lower substrate and heated and pressurized to melt the heat-dissolving adhesive layer of the flexible wiring board to thereby melt the upper substrate and the lower substrate. In the step of bonding the plates, the alignment is omitted by simply overlapping the upper substrate, the flexible wiring board, and the lower substrate.

Further, according to the present invention, a flexible wiring board is disposed between the upper substrate and the lower substrate and heated and pressurized to melt the heat-dissolving adhesive layer of the flexible wiring board to thereby melt the upper substrate and the lower substrate. bonding in the step of bonding the plate, only the heating and pressing the outer peripheral portion of the flexible wiring board of the upper substrate and the lower substrate, and melting the heat-dissolving type adhesive layer of the lower base plate and the substrate At the same time, the metal particles contained in the conductive paint are penetrated through the heat-dissolving adhesive layer.

  The structural effects are as follows.

  According to the present invention, the position detection electrodes in the X direction or the Y direction are provided opposite to each other on the front and back surfaces of the frame-shaped flexible wiring board, and the lead electrodes are arranged around the position detection electrodes. Since the electrode is covered and a heat-dissolving adhesive layer is formed in a frame-like width, the entire flexible wiring board can be used as an adhesive region, and a conductive paint containing metal particles is attached to the surface of the position detection electrode. Thus, the metal particles can pass through the heat-dissolving adhesive layer to connect the position detection electrode and the transparent electrode film, and the connection region can be disposed so as to overlap the adhesion region.

  As a result, an adhesive region of the entire width of the frame shape can be secured on the flexible wiring board, so that the adhesive strength of the upper substrate or the lower substrate is greatly improved. As a result, the region for forming the position detection electrode and the lead electrode can be formed in the adhesion region, so that the frame width of the flexible wiring board can be suppressed to the minimum value, and the frame width of the flexible wiring board can be reduced. This makes it possible to realize a narrow frame of a touch panel that sufficiently maintains the adhesive strength between the upper and lower substrates.

  In addition, since the metal particles penetrate the heat-dissolving adhesive layer and connect the position detection electrode and the transparent electrode film, the electrical connection between the position detection electrode and the transparent electrode film is a mechanical connection by pressure bonding. Thus, a reliable electrical connection can be realized.

  As a result, since the touch panel can be realized with the minimum components of the upper and lower substrates and the flexible wiring board, the price of the high-quality glass-glass touch panel can be greatly reduced.

  The effects on the manufacturing method are as follows.

  According to the present invention, the process of cutting the transparent electrode film into an upper substrate and a lower substrate having a transparent electrode film on one side substantially the same size as the individual touch panel without etching the transparent electrode film for pattern formation; A position detection electrode and a lead electrode are formed on both sides of the frame shape, a conductive paint containing metal particles is attached to the surface of the position detection electrode, and the position detection electrode and the lead electrode are covered to form a heat-dissolving adhesive layer The step of preparing a frame-shaped flexible wiring board, the flexible wiring board is disposed between the upper substrate and the lower substrate, the upper substrate and the lower substrate are bonded by heating and pressing, and the metal contained in the conductive paint at the same time The touch panel can be manufactured in all three steps of electrically connecting the particles through the heat-dissolving adhesive layer. Thereby, the manufacturing method of the touch panel with the minimum number of processes without an etching process can be established.

  In addition, the process of forming dot spacers and patterning of transparent electrode films is excluded from the manufacturing process, eliminating the need for a photo-etching process having a series of many processes, greatly reducing the number of processes, and resulting equipment. This leads to a significant reduction in investment and manufacturing costs.

  Specifically, as a result of eliminating the etching equipment having many processes, the space of the etching equipment which is about 60 m can be used effectively, and the manufacturing time which was 420 seconds in the conventional manufacturing method is less than half. It can be shortened to about 180 seconds.

  Furthermore, in the bonding process of the upper and lower substrates and the flexible wiring board, the upper substrate, the lower substrate and the flexible wiring board are formed in substantially the same size, so that the upper and lower substrates are simply sandwiched between the flexible wiring boards. There is no need to align just by overlapping. And since only the outer peripheral part is heated and pressed from the upper and lower substrates for bonding, the upper and lower substrates and the flexible wiring board can be bonded together. In this process, the metal particles contained in the conductive paint are penetrated through the heat-dissolving adhesive layer and the position detection electrode and the transparent electrode film are electrically connected, so that the bonding and connection can be realized in a single process. .

  Furthermore, since the conductive paint is attached on the position detection electrode, the metal particles penetrate only the heat-dissolving adhesive layer and mechanically contact with the transparent electrode film only from the position detection electrode. The position where the paint is placed automatically becomes a position detection electrode, and self-alignment can be realized in which no alignment is required. Accordingly, there is no need to prevent the position detection electrode portion and the adhesive layer from overlapping each other as in the prior art.

  Furthermore, in the bonding process of the upper and lower substrates and the flexible wiring board, the upper and lower substrates are bonded by heating and pressurizing only the outer peripheral part of the flexible wiring board. This part does not curve to the lower substrate side. Thereby, since the gap between the upper substrate and the lower substrate is maintained at the thickness of the flexible wiring board, the air sealing step and the opening sealing step can be excluded from the conventional manufacturing process.

  Further, according to the present invention, the size of the upper substrate and the lower substrate is set to be substantially the same size, and the glass plate as the mother base is approximately an integral multiple of the size of the upper substrate or the lower substrate of the individual touch panel. Is set. Since the external extraction electrode protrudes from a part of the frame of the flexible wiring board and is arranged between the upper substrate and the lower substrate, the eaves portion of the lower substrate provided in the conventional touch panel becomes unnecessary. Thereby, it is not necessary to cut a part of the upper substrate when cutting the upper and lower substrates from the glass plate, and the disposal of the glass plate which is the mother substrate can be made almost zero.

  Due to the effects detailed above, the glass-glass touch panel manufactured by the manufacturing method of the present invention can reduce the number of manufacturing steps to a minimum even if an expensive thin glass plate is used. A great advantage can be realized that can realize a glass-glass touch panel that can compete with price. In addition, even if the manufacturing method of this invention is applied to the touch panel of a film-glass structure, the number of manufacturing processes can be reduced similarly and cost can also be reduced significantly.

FIG. 1 is a plan view illustrating a touch panel according to the present invention. FIG. 2 (A) is a plan view for explaining the surface of the frame-shaped flexible wiring board of the present invention, and FIG. 2 (B) is a sectional view thereof. FIG. 3A is a plan view for explaining the back surface of the frame-shaped flexible wiring board of the present invention, and FIG. 3B is a sectional view thereof. FIG. 4 is a cross-sectional view of the touch panel of the present invention. FIG. 5A is a partially enlarged cross-sectional view illustrating a state before the frame-shaped flexible wiring board of the present invention is bonded, and FIG. 5B is a diagram illustrating the state after the bonding. FIG. 6A to 6D are process flow diagrams illustrating the manufacturing process of the touch panel of the present invention. FIG. 7 is a plan view for explaining a conventional method for manufacturing a glass-glass touch panel. FIG. 8 is a plan view for explaining a conventional method for manufacturing a glass-glass touch panel. FIG. 9 is a flowchart for explaining a general photoetching process.

  The structure of the touch panel of the present invention will be described with reference to FIGS.

  FIG. 1 is a plan view illustrating a touch panel according to the present invention.

  The touch panel of the present invention has an upper substrate provided with a transparent electrode film on one side, a lower substrate provided with a transparent electrode film on one side, and two X-direction position detection electrodes opposed to one main surface. A lead electrode is routed from the position detection electrode to the external lead electrode, and two Y direction position detection electrodes are opposed to the opposite main surface, and the lead electrode is routed from the Y direction position sense electrode to the external lead electrode. Then, a conductive paint containing metal particles is attached to the surface of the position detection electrode in the X direction and the Y direction, and the position detection electrode and the extraction electrode in the X direction and the Y direction are covered to form a heat-dissolving adhesive layer A frame-like flexible wiring board formed with a metal particle of the conductive paint, penetrating the heat-dissolving adhesive layer with the position detection electrode in the X direction or the Y direction, and the upper substrate. A transparent electrode film of the lower substrate are electrically connected, characterized by bonding the substrate and the lower substrate sandwiching the flexible wiring board in the heating dissolution type adhesive layer together.

  As shown in FIG. 1, the touch panel 1 includes a lower substrate 20 provided with a transparent electrode film 21 on one side, a frame-shaped flexible wiring board 30 overlaid on the transparent electrode film of the lower substrate, and a flexible wiring board. The upper substrate 10 is provided with a transparent electrode film 11 on one side.

  The upper substrate 10 and the lower substrate 20 are cut out to approximately the same size from the glass plates 2 and 3 which are mother base materials. Specifically, the size of the upper substrate 10 and the lower substrate 20 is 190 mm × 120 mm, and the size of the glass plates 2 and 3 is 380 mm × 240 mm. Therefore, there are four upper and lower substrates than one glass plate. Can be cut out.

  For the glass plates 2 and 3, a transparent glass material having a thickness of 0.2 mm is used as the upper substrate 10, and transparent glass having a thickness of 1.1 mm is used as the lower substrate 20. Transparent electrode films 11 and 21 are formed on the back surfaces of the respective glass plates 2 and 3. In addition, by using glass instead of film for the glass plate, even if the transparent electrode film formed on one side is not etched with the cutting line of the upper and lower substrates, the glass plate is diced with a diamond cutter and divided into each substrate size. At the same time, the transparent electrode films can be divided together. However, in the case of a small touch panel, the transparent electrode films 11 and 21 around the upper and lower substrates 10 and 20 may be removed by etching to prevent peeling.

  In addition, although the glass board is demonstrated here as a mother base material, this invention is applicable also with a film or a resin board.

  The flexible wiring board 30 has a shape in which the outer periphery of a portion to be a touch area of the upper substrate and the lower substrate is surrounded by a frame shape, and the frame-shaped portion is formed with a width of 2.5 mm and a constant width on the entire periphery. A terminal plate 31 for an external extraction electrode is formed which protrudes in a rectangular shape with a width of 2.5 mm and a length of 15 mm from a part of the portion. A polyimide resin with a thickness of 25 μm is used for the base film of the flexible wiring board. Further, a polyimide resin film having a thickness of about 175 μm is attached to the back surface of the terminal board 31 to reinforce the external extraction electrodes 36 and 37. The flexible wiring board will be described in detail with reference to FIGS.

  The X-axis position detection electrode 32 or the Y-axis position detection electrode 34 is formed on the base film of the flexible wiring board 30 by screen printing silver paste or the like. Two X-axis position detection electrodes 32 are opposed to one main surface of the flexible wiring board, and two Y-axis position detection electrodes 34 are opposed to the opposite main surface. A conductive paint 40 is applied to the surface of the position detection electrodes 32, 34. Specifically, each position detection electrode is formed by screen printing of 0.015 mm thick Ag wiring.

  As the conductive paint 40, a mixture of silver, nickel particles 41 and a binder is used.

  The heat-dissolving adhesive layer 39 is on the base film of the flexible wiring board and overlaps the X-axis and Y-axis position detection electrodes 32 and 34 and the extraction electrodes 33 and 35 to form a frame-like width of the flexible wiring board. It is formed in layers. A hot melt resin is used for the heat-dissolving adhesive layer.

  The conductive paint 40 has an insulating property in an initial state before heating, and the binder is dissolved and changed into a conductive property by heating and pressurizing with a hot heater under a certain pressure bonding condition. Then, it is electrically connected to the transparent electrode film while being bonded to the upper and lower substrates. This connection operation principle will be described in detail with reference to FIG.

  The X-axis or Y-axis lead electrodes 33 and 35 are arranged around the position detection electrodes 32 and 34. At the same time as the position detection electrodes, Ag wiring is formed on the base film of the flexible wiring board 30 by screen printing. Apply. Since the lead electrode does not need to be electrically connected to the transparent electrode films 11 and 12, it is not necessary to apply the conductive paint 40 on the surface thereof, and is directly covered with the insulating heat-dissolving adhesive layer 39.

  The X-axis or Y-axis external extraction electrodes 36 and 37 are provided side by side on the back surface of the terminal board 31 of the flexible wiring board 30, and Ag wiring is performed on the base film by screen printing in the same manner as the position detection electrodes. The X-axis external extraction electrode 36 is connected to the X-axis extraction electrode 33 using a through-hole electrode 38. Since the terminal plate 31 protrudes from between the upper and lower substrates 10 and 20, the protruding portion is reinforced with UV resin (not shown) in order to give mechanical strength.

  Next, the structure of the flexible wiring board of this invention is demonstrated using FIG. 2 and FIG. FIG. 2 (A) is a plan view for explaining the surface of the frame-shaped flexible wiring board of the present invention, and FIG. 2 (B) is a sectional view thereof. FIG. 3A is a plan view for explaining the back surface of the frame-shaped flexible wiring board of the present invention, and FIG. 3B is a sectional view thereof.

  As shown in FIG. 2A, two X-axis position detection electrodes 32 for detecting the position in the X direction along the right side and the left side are provided on the surface side of the frame-shaped flexible wiring board 30. Yes. The outside of the X axis formed on the back surface of the terminal plate 31 that is drawn from the X axis position detection electrode 32 along the periphery of the frame-shaped flexible wiring board 30 by the extraction electrode 33 and protrudes from a part of the frame. Connected to the extraction electrode 36. Since the X-axis external lead electrode 36 is on the back surface of the terminal plate 31, it is connected to the lead electrode 33 using the through-hole electrode 38.

  Then, the heat-dissolving adhesive layer 39 is formed in a frame-like width so as to overlap the X-axis position detection electrode 32 or the X-axis lead electrode 33. An insulating adhesive layer is used as the heat-dissolving adhesive layer, and it is formed only on the frame-shaped portion of the flexible wiring board 30. Therefore, it is not necessary to form a heat-dissolving adhesive layer on the temporary terminals 31 that are arranged to protrude from the upper and lower substrates during bonding. Specifically, a hot-melt resin is used for the heat-dissolving adhesive layer 39, and a layer having a thickness of 0.0325 mm and a width of 2.5 mm is formed on the front and back surfaces of the frame-shaped base film. The thickness h1 of 30 is 0.090 mm.

  Since the flexible wiring board 30 of the present invention is provided with an adhesive layer over the entire width of the frame, a sufficient adhesion area can be secured. Thereby, even if it is a narrow frame, the adhesive strength of an upper board | substrate or a lower board | substrate and a flexible wiring board increases significantly, and there exists an effect which can provide the adhesive strength which can fully endure the press operation of a touch panel.

  The cross-sectional view in FIG. 2B corresponds to a portion indicated by line XX in FIG. As shown in the figure, an X-axis position detection electrode 32 is formed on the surface of the base film of the flexible wiring board, and a Y-axis lead electrode 35 is formed on the back surface of the base film. A conductive paint 40 is applied to the surface of the X-axis position detection electrode 32 so as to form a position detection electrode. In the conductive paint 40, silver, nickel particles 41, and a binder are mixed. The nickel particles 41 have a conductive property, but the nickel particles are covered with a binder layer before bonding.

  Since the insulating heat-dissolving adhesive layer 39 is formed on the frame-like width by overlapping the position detection electrode or the extraction electrode, it is transparent only by sandwiching the flexible wiring board 30 between the upper and lower substrates. The electrode film and the position detection electrode are not electrically connected.

  Here, the state in which the center positions of the X-axis position detection electrode 32 on the surface of the base film and the Y-axis lead-out electrode 35 on the back surface of the base film are aligned is shown in the figure, but an insulating material is provided on the base film. Since they are used, both are insulated. In this case, since the X-axis position detection electrode 32 and the Y-axis lead electrode 35 are overlapped with each other, a touch panel with a narrower frame can be realized without lowering the adhesive strength and when both are shifted.

  As shown in FIG. 3A, the rear surface side of the frame-shaped flexible wiring board 30 is a Y-axis position detection electrode for detecting the position in the Y direction along the upper side and the lower side, similarly to the surface side described above. 34 and an extraction electrode 35 are formed and connected to a Y-axis external extraction electrode 37 formed on the back surface of the terminal plate 31. The Y-axis external extraction electrode 37 is provided on the back surface of the terminal plate 31 side by side with the X-axis external extraction electrode 36.

  The cross-sectional view in FIG. 3B corresponds to a portion indicated by a YY line in FIG. As shown in the figure, on the front and back surfaces of the base film of the flexible wiring board, a heat-dissolving adhesive layer 39 is formed in a frame-like width so as to overlap the position detection electrode or the extraction electrode. Since the frame-like flexible wiring board 30 shown in FIG. 2 and the frame-like flexible wiring board 30 shown in FIG. 3 are reversed, the conductive paint 40 is on the upper side.

  The details are the same as those on the surface side described above, and will be omitted.

  Next, using FIG. 4 and FIG. 5, the principle of connection operation between the position detection electrode and the transparent electrode film, which is a feature of the present invention, will be described. FIG. 4 is a cross-sectional view of a touch panel using the glass substrate of the present invention. FIG. 5A is a partially enlarged cross-sectional view illustrating a state before the frame-shaped flexible wiring board of the present invention is bonded, and FIG. 5B is a diagram illustrating the state after the bonding. FIG. 4 corresponds to the portion indicated by the line AA in FIG. 1, and the partially enlarged sectional views of FIGS. 5A and 5B correspond to the portion surrounded by the dotted line in FIG. doing.

  As shown in FIG. 4, the upper substrate 10 and the lower substrate 20 of the completed touch panel 1 are firmly bonded to each other with a sufficient width by a heat-dissolving adhesive layer 39 of the flexible wiring board 30, and position detection electrodes 32 of the flexible wiring board. , 34 and the transparent electrode films 11 and 21 on the upper and lower substrates are reliably electrically connected.

  However, as described above, the front and back surfaces of the flexible wiring board 30 are covered with the insulating heat-dissolving adhesive layer 39. For this reason, as shown in FIG. 5A, in the state before being bonded to the upper and lower substrates, the heat-dissolving adhesive layer 39 exists between the position detection electrode and the transparent electrode film and is not conductive. Recognize. The flexible wiring board 30 having such a structure can reliably connect the position detection electrode and the transparent electrode film by heating and pressurizing under a predetermined pressure bonding condition.

  Here, the connection operation principle will be described with reference to FIG.

  First, the outer peripheral portions of the upper substrate 10 and the lower substrate 20 are sandwiched by a head heater under a predetermined pressure bonding condition (see FIG. 6D), and heated and pressurized. Specifically, the pressure bonding condition is set to a temperature of 150 ° C. to 160 ° C. for 13 seconds.

  When heating and pressurization are performed under these pressure bonding conditions, the binder in the conductive paint 40 is dissolved and the nickel particles 41 protrude from the surface. Further, the heat-dissolving adhesive layer 39 between the position detection electrodes 32 and 34 and the transparent electrode films 11 and 21 is also melted and compressed by heat and pressure. Then, as shown in FIG. 5B, the protruding hard nickel particles 41 penetrate through the heat-dissolving adhesive layer 39, and the position detection electrode and the transparent electrode film are reliably connected via the nickel particles.

  The nickel particles 41 are selected in the range of 20 to 30 μm in average particle diameter, and maintain the shape as they are even when pressed due to their hardness, so that they penetrate the heat-dissolving adhesive layer 39. Since silver stays around the nickel particles 41 and fills the gaps between the nickel particles 41, the position detection electrode and the transparent electrode film are more reliably connected.

  If this connection operation principle is used, the position detection electrodes 32 and 34 and the transparent electrode films 11 and 21 can be reliably electrically connected, while the extraction electrodes 33 and 35 and the transparent electrode films 11 and 21 are heated and dissolved. The adhesive layer 39 can ensure insulation. As a result, it is possible to exclude the step of positioning before the upper and lower substrate bonding steps, which is necessary in the manufacture of the conventional touch panel. That is, self-alignment can be realized.

  In addition, when the position detection electrode and the extraction electrode are arranged to overlap with each other, an unnecessary force is not applied to the step portion at the time of crimping compared to the case where the position detection electrode and the extraction electrode are arranged to be shifted, so that the possibility of disconnection can be eliminated.

  Furthermore, the heat-dissolving adhesive layer 39 is compressed by heating and pressurization from the top and bottom directions, and then cooled to keep the height of the flexible wiring board 30 at h2. Specifically, the thickness (h1) of the flexible wiring board 30 before heating and pressing is 0.090 mm, but it is compressed to 60 to 70% by heating and pressing, and the thickness (h2) is 0. 0.054 to 0.063 mm.

  Since the gap between the upper and lower substrates is maintained at the height h2 of the flexible wiring board 30 after compression, dot spacers and spacer beads, which are necessary for maintaining a stable gap in the conventional touch panel structure, are unnecessary. It is also possible to eliminate the need for an air-filling opening provided in a part of the sealant.

  In the touch panel having the above-described structure, when an arbitrary point in the touch area of the touch panel is pressed with a finger or a pen, the transparent electrode film on the upper substrate and the transparent electrode film on the lower substrate come into contact and turn on at that point. . The resistance value of the transparent electrode film is detected by the position detection electrode of the flexible wiring board, and the X coordinate and Y coordinate of the point can be known. The coordinate information is sent to the CPU of the input device via each extraction electrode and external extraction electrode of the flexible wiring board, and processing corresponding to the coordinate information is performed.

  When the pressing operation is stopped, the transparent electrode film on the upper substrate and the transparent electrode film on the lower substrate are separated from each other, and the processing corresponding to the coordinate information ends.

  Next, an example of the manufacturing method of the present invention will be described with reference to FIG.

  FIG. 6: has shown the process flow figure explaining each manufacturing process of the touchscreen using the glass substrate of this invention.

  First, as shown in FIGS. 6A and 6B, in the process of dividing the glass plates 2 and 3 which are mother base materials into the upper substrate 10 and the lower substrate 20, two glass plates 2 having different thicknesses are used. 3 is deposited on the entire surface of one side to form an ITO film. Then, without etching the ITO film, the glass substrate is divided into an upper substrate 10 and a lower substrate 20 each having an ITO film on the entire surface having substantially the same size as the individual touch panel.

  For the glass plates 2 and 3, a transparent glass material having a thickness of 0.2 mm is used as the upper substrate 10, and a transparent glass material having a thickness of 1.1 mm is used as the lower substrate 20. Transparent electrode films 11 and 21 are formed on one entire surface of each glass plate 2 and 3. The sizes of the glass plates 2 and 3 are set to be approximately an integral multiple of the size of the upper substrate 10 and the lower substrate 20, and the upper substrate 10 and the lower substrate 20 are substantially the same size. Specifically, the size of the upper substrate 10 and the lower substrate 20 is 190 mm × 120 mm, and the size of the glass plates 2 and 3 is 380 mm × 240 mm. Therefore, there are four upper and lower substrates than one glass plate. Can be cut out.

  The sizes of the upper substrate 10 and the lower substrate 20 are appropriately required depending on the size of the touch panel.

  The upper substrate 10 is divided into the size of the upper substrate 10 with the transparent electrode film remaining on the entire surface without etching the transparent electrode film 11 of the glass plate 2 having a thickness of 0.2 mm.

  The lower substrate 20 is also divided into the size of the lower substrate 20 with the transparent electrode film left on the entire surface without etching the transparent electrode film 21 of the glass plate 3 having a thickness of 1.1 mm.

  In this process, as in a conventional touch panel, a position detection electrode for detecting positions in the X direction and the Y direction on the transparent electrode films on the upper substrate and the lower substrate, and an extraction electrode from each position detection electrode along the periphery of each substrate Therefore, the process of etching the transparent electrode films on the upper substrate and the lower substrate into the pattern of the transparent electrode is unnecessary. However, in a small touch panel, the transparent electrode film around the upper and lower substrates 10 and 20 may be removed by etching in order to prevent the peeling of the transparent electrode film.

  As a result, after washing and removing the dirt and drying the substrate, the substrate is coated with a photoresist and the surface is dried, then the pattern is exposed and developed, and the unexposed portion of the photoresist layer is removed, Etching with a solution such as hydrochloric acid using the remaining photoresist layer as a mask, immersing and removing the remaining photoresist layer in a solution such as sodium hydroxide, and then cleaning the substrate to remove chemicals and dirt. The photoetching process including the process can be excluded.

  Next, in the step of preparing the flexible wiring board 30, the position detection electrode 32 and the extraction electrode 33 in the X direction are formed on one main surface, and the position detection electrode 34 and the extraction electrode 35 in the Y direction are formed on the opposite main surface. A frame-like flexible wiring board in which the heat-dissolving adhesive layer 39 is formed in a frame-like width so as to overlap the position detection electrode and the extraction electrode, and the extraction electrode 33 is provided on the terminal board 31 protruding from a part of the frame. , 35 are extended to form a flexible wiring board 30 on which external extraction electrodes 36 and 37 are formed. A conductive paint is applied to the surface of the position detection electrode.

  The flexible wiring board 30 has a shape in which the outer periphery of a portion to be a touch area of the upper substrate and the lower substrate is surrounded by a frame shape, and the frame-shaped portion is formed with a width of 2.5 mm and a constant width on the entire periphery. A terminal plate 31 for an external extraction electrode is formed which protrudes in a rectangular shape with a width of 2.5 mm and a length of 15 mm from a part of the portion. A polyimide resin film having a thickness of about 175 μm is attached to the back surface of the terminal board 31 to reinforce the external extraction electrodes 36 and 37.

  The position detection electrode 32 and extraction electrode 33 in the X direction provided on one main surface, and the position detection electrode 34 and extraction electrode 35 in the Y direction provided on the opposite main surface are attached by screen printing using silver paste, and then baked silver It is formed as a wiring. The external extraction electrodes 36 and 37 are simultaneously formed by screen printing. Thereafter, the conductive paint 40 is screen-printed on the position detection electrode 32 in the X direction and the position detection electrode 34 in the Y direction, and the heat-dissolving adhesive layer 39 is formed on the entire frame-like flexible wiring board. Since the nickel particles 41 in the conductive paint 40 penetrate through the heat-dissolving adhesive layer 39 and work as the position detection electrodes of the transparent electrode films 11 and 21, the position detection electrodes 32 and 34 of the flexible wiring board 30 are Even if it does not align with high accuracy, it is only necessary to overlap in part and make electrical contact.

  The base film of the flexible wiring board 30 includes an X-direction position detection electrode 32 and an extraction electrode 33 provided on one main surface, and a Y-direction position detection electrode 34 and an extraction electrode 35 and external extraction electrodes 36 and 37 provided on the opposite main surface. Alternatively, the copper foil provided on both sides may be etched and nickel-plated on the surface. In this case, since the flexible wiring board 30 is supplied from the printed board manufacturer, the touch panel manufacturer does not need an etching process. In the printed board manufacturer, the copper foil can be etched with existing equipment. No problem.

  In addition, since the terminal board protrudes from a part of the frame of the flexible wiring board, the connection part of the external electrode on the lower substrate, which is necessary in the conventional touch panel, is not necessary. Accordingly, it is not necessary to form the eaves portion of the lower substrate, and it is not necessary to cut a part of the upper substrate in order to expose the eaves portion. As a result, when the upper substrate and the lower substrate are divided from the glass plate, the discard amount of the glass plate can be made substantially zero. In addition, since a chip | tip etc. generate | occur | produce in the peripheral part of the glass plates 2 and 3, it is necessary to remove a peripheral part only width of several millimeters, and all the glass plates to which this peripheral part is discarded are discarded.

  Further, as shown in FIG. 6C, in the step of bonding the upper substrate 10 and the lower substrate 20, the flexible wiring board 30 is overlaid on the transparent electrode film 21 of the lower substrate 20 and on the outer periphery thereof. Further, the upper substrate 10 is placed in an overlapping manner, and the outer peripheral portion of the flexible wiring board 30 is heated and pressurized with a plate to bond the upper substrate 10, the flexible wiring board 30 and the lower substrate 20, and at the same time the X axis or Y axis The position detection electrodes 32 and 34 and the transparent electrode films 11 and 21 are electrically connected.

  In this step, the upper substrate 10, the flexible wiring board 30, and the lower substrate 20 are simply arranged in the heating jig 42 with their outer peripheral portions aligned. Then, as shown in FIG. 6D, the upper substrate 10 and the lower substrate 20 on which the flexible wiring board 30 is located are selectively heated and pressed by a heater head 43 having a melting temperature for a predetermined time, and the upper substrate is fixed. 10, the flexible wiring board 30 and the lower substrate 20 are bonded, so that only the frame-like flexible wiring board 30 is pressed, and the central portion serving as the touch area is not pressed. Accordingly, since the thin upper substrate 10 is pulled outward, the gap between the upper substrate 10 and the lower substrate 20 is regulated by the thickness of the heat-dissolving adhesive layer 39 of the flexible wiring board 30. For this reason, the gap between the upper substrate 10 and the lower substrate 20 can be formed without using the dot spacers and spacer beads that have been used conventionally, and this gap can be maintained, so that the heat-dissolving adhesive layer 39 has a conventional opening. It is no longer necessary to provide

  In this step, the portion where the heat-melt adhesive layer 39 formed so as to overlap the position detection electrodes 32 and 34 and the lead electrodes 33 and 35 of the flexible wiring board 30 is sandwiched by the heater head 43, specifically 150 ° C. Heat and pressurize at ~ 160 ° C for 13 seconds. The binder in the conductive paint 40 on the surface of the position detection electrode and the heat-dissolving adhesive layer 39 are dissolved, the nickel particles 41 in the conductive paint 40 are exposed, and the hard nickel particles penetrate the heat-dissolving adhesive layer 39. . Thereby, the position detection electrodes 32 and 34 and the transparent electrode films 11 and 21 are electrically connected through the nickel particles 41 and the surrounding silver.

  In addition, since the position detection electrode and the transparent electrode film are securely bonded according to the above-described connection operation principle, the alignment step is not necessary and self-alignment can be realized.

DESCRIPTION OF SYMBOLS 1 Touch panel 2 Glass plate 3 Glass plate 10 Upper substrate 11 Transparent electrode film 20 Lower substrate 21 Transparent electrode film 30 Flexible wiring board 31 Terminal board 32 X-axis position detection electrode 33 X-axis extraction electrode 34 Y-axis position detection electrode 35 Y-axis extraction Electrode 36 X-axis external extraction electrode 37 Y-axis external extraction electrode 38 Through-hole electrode 39 Heat-dissolving adhesive layer 40 Conductive paint 41 Nickel particle 42 Heating jig 43 Heater head 50 Element section 51 Seal layer 52 Opening 53 Peripheral seal layer 54 row direction cut line 55 sealing member 56 transparent electrode 57 dot spacer 58a position detection electrode 58b lead-out electrode 59 temporary terminal 60 connector 61 external extraction electrode

Claims (8)

An upper substrate provided with a transparent electrode film on one side;
A lower substrate provided with a transparent electrode film on one side;
Two position detection electrodes in the X direction are opposed to one main surface, the extraction electrodes are routed from the position detection electrode in the X direction to the external extraction electrode, and two position detection electrodes in the Y direction are opposed to the opposite main surface. A conductive electrode containing metal particles is attached to the surface of the position detection electrode in the X direction and the Y direction, and the X direction And a frame-like flexible wiring board in which an insulating heat-dissolving adhesive layer is formed on both main surfaces so as to overlap the position detection electrode and the extraction electrode in the Y direction and the conductive paint ,
The heat soluble type adhesive layer through the said transparent electrode film of the upper substrate or the lower substrate and the X direction or the Y-direction of the position detection electrodes are electrically connected by the metal particles of the conductive coating ,
Touch panel characterized by adhering together a prior SL on the substrate and the lower substrate in the heating dissolution type adhesive layer of the flexible wiring board.   2. The touch panel according to claim 1, wherein the conductive paint covers the entire surface of the position detection electrodes in the X direction and the Y direction, and the heat-dissolving adhesive layer covers the entire surface of the flexible wiring board. .   The touch panel as set forth in claim 1, wherein the conductive paint is mixed with at least silver and nickel metal particles and a binder.   The touch panel according to claim 1, wherein a thin glass substrate is used for the upper substrate, and a glass substrate thicker than the upper substrate is used for the lower substrate. A transparent electrode film is formed on one side of two mother substrates having different thicknesses, and the mother substrate is divided into an upper substrate and a lower substrate each having the transparent electrode film on one side of the same size as an individual touch panel. And a process of
A position detection electrode and an extraction electrode in the X direction are formed on one main surface, a position detection electrode and an extraction electrode in the Y direction are formed on the opposite main surface, and metal particles are formed on the surface of the position detection electrode in the X direction and the Y direction. A frame shape in which an insulating heat-dissolving adhesive layer is formed on both main surfaces so as to overlap the position detection electrodes and lead electrodes in the X and Y directions and the conductive paint. Preparing a flexible wiring board of
Heating and pressing by placing a flexible wiring board between the lower substrate and the substrate, and the adhesion of the lower base plate and the substrate by melting the heat-dissolving type adhesive layer of the flexible wiring board, At the same time, the metal particles contained in the conductive paint are passed through the heat-dissolving adhesive layer to electrically connect the position detection electrode in the X direction or the Y direction and the transparent electrode film on the upper substrate or the lower substrate. And a step of electrically connecting the touch panel.   The touch panel manufacturing method according to claim 5, wherein the mother base material uses glass plates having different thicknesses and is set to a size that is approximately an integral multiple of the size of the upper substrate or the lower substrate. . Heating and pressing by placing a flexible wiring board between the lower substrate and the upper substrate, in the step of bonding the heat soluble type adhesive layer and the substrate by melting the lower board of the flexible wiring board 6. The method of manufacturing a touch panel according to claim 5, wherein the alignment is omitted by simply overlapping the upper substrate, the flexible wiring board, and the lower substrate. Heating and pressing by placing a flexible wiring board between the lower substrate and the upper substrate, in the step of bonding the heat soluble type adhesive layer and the substrate by melting the lower board of the flexible wiring board only the heating and pressing the outer peripheral portion of the flexible wiring board of the upper substrate and the lower substrate, and melting the heat-dissolving type adhesive layer performs the adhesion of the lower base plate and the substrate, simultaneously the conductive The method for manufacturing a touch panel according to claim 5, wherein the metal particles contained in the conductive paint are caused to penetrate the heat-dissolving adhesive layer.

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