JP4855536B1 - Manufacturing method of touch input sheet with excellent rust prevention - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch input sheet manufacturing method suitable for a capacitive touch sensor having a narrow frame and a transparent conductive film pattern having two layers, and having excellent rust prevention.
The present invention uses a conductive sheet in which a transparent conductive film, a light-shielding conductive film, and a first photoresist layer are sequentially laminated on both sides of a transparent substrate sheet, and the first photoresist layer is formed on both sides simultaneously. After the exposure and development, the transparent conductive film and the light-shielding conductive film are simultaneously etched, and after the first photoresist layer is peeled off, a rust inhibitor is added and patterned on the exposed light-shielding conductive film. Laminate a photoresist layer, etch only the light-shielding conductive film in the central window and terminal part, expose the transparent conductive film, peel off the second photoresist layer, then rust-proof the exposed light-shielding conductive film Cover with membrane.
[Selection] Figure 3

Description

  The present invention relates to a touch input sheet suitable for a capacitive touch sensor having a narrow frame and a transparent conductive film pattern having two layers, and a manufacturing method thereof.

  Conventionally, after forming a metal film on each terminal of the lead terminal of the transparent electrode, the transparent electrode pattern in the input panel region and the metal film and the transparent electrode in the lead terminal row are simultaneously etched to form a touch input device. There was Patent Document 1 as a document.

  In the invention of Patent Document 1, as shown in FIG. 6, a transparent electrode made of an ITO film 31 is formed on a polyester film 30, a photoresist film 32 is formed on the transparent electrode, and then on the photoresist film 32. After covering with a mask 33, a metal film 34 made of In film is formed, the mask 33 is removed, the photoresist film 32 is removed with a resist stripping solution, and the metal film 34 is patterned, and then patterned. A second photoresist film 35 is formed on the formed metal film 34 (see FIG. 6E), and the metal film 35 and the ITO film 31 are simultaneously etched away with a ferric chloride aqueous solution or the like. It is an invention of a method of removing the resist film 35 with a resist stripping solution.

Japanese Patent Laid-Open No. 5-108264

  However, according to the method of Patent Document 1, when the second photoresist film 35 is patterned on the patterned metal film 34 shown in FIG. The metal film 34 is thin and the other metal film 34 is thick, and the metal film 34 does not have a desired electrical resistance. Therefore, there is a problem that the metal film 34 cannot be applied to a touch input sheet with a narrow frame in which the metal film 34 must be within a predetermined electric resistance range with a thin line.

  Moreover, in the capacitive touch input sheet, it is necessary to laminate a transparent conductive film pattern normally formed in the X direction and a transparent conductive film pattern formed in the Y direction with an insulating layer interposed therebetween, In the method of Patent Document 1, the metal film and the transparent electrode cannot be formed on the both surfaces in the same position, so two touch input sheets that have been manufactured must be manufactured through a process such as bonding them in position. There was a problem. As a result, there was a problem that the production was reduced, the transmittance of the transparent window portion was lowered, and the thickness became thicker.

  Accordingly, an object of the present invention is to solve the above-mentioned problem, and is suitable for a capacitive touch sensor having a narrow frame and a transparent conductive film pattern having two layers, and further having excellent rust prevention properties. It is in providing the manufacturing method of.

According to the first aspect of the present invention, a process of obtaining a conductive film in which a transparent conductive film, a light-shielding conductive film, and a first photoresist layer are sequentially laminated on both surfaces of a transparent substrate sheet,
Partially exposing the first photoresist layer on both sides simultaneously and developing each pattern by developing; and
By simultaneously etching and removing the transparent conductive film and the light-shielding conductive film in the portion where the patterned first photoresist layer is not laminated, the transparent conductive film and the light-shielding are respectively formed in the central window portions on both sides of the base sheet. Forming an electrode pattern in which the conductive film is laminated without misalignment, and forming a thin line drawing circuit pattern in which the transparent conductive film and the light-shielding conductive film are laminated without misalignment on the outer frame portions on both sides of the base sheet. When,
After peeling off the first photoresist layer, a step of laminating a second photoresist layer on the entire surface on which the electrode pattern and the fine line drawing circuit pattern are formed;
Partially exposing the second photoresist layer on both sides simultaneously and developing each pattern by developing; and
By etching away only the light-shielding conductive film in the portion where the patterned second photoresist layer is not laminated, the transparent conductive film is exposed at the central window portion and the terminal portion on both sides of the base sheet. A process of
And a step of coating the exposed light-shielding conductive film with a rust-proofing functional film after peeling off the second photoresist layer, and a method for producing a touch input sheet having excellent rust-proofing characteristics .

  According to the 2nd aspect of this invention, the manufacturing method of the touch input sheet | seat excellent in the rust prevention property of the 1st aspect which is the said rust prevention functional film formed by the printing method is provided.

  According to the 3rd aspect of this invention, the manufacturing method of the touch input sheet | seat excellent in the rust prevention property of the 1st aspect which the said antirust function film | membrane is formed of the photo process is provided.

  According to the 4th aspect of this invention, manufacture of the touch input sheet excellent in the antirust property in any one of the 1st-3rd aspect whose said transparent conductive film is ITO film | membrane and the said light-shielding conductive film is copper foil. Method.

  The touch input sheet manufacturing method of the present invention includes a step of obtaining a conductive film in which a transparent conductive film, a light-shielding conductive film, and a first photoresist layer are sequentially laminated on both surfaces of a transparent substrate sheet, respectively. The first photoresist layer is partially exposed on both sides simultaneously and developed to form a pattern, respectively, the transparent conductive film in the portion where the patterned first photoresist layer is not laminated, and the By simultaneously etching and removing the light-shielding conductive film, an electrode pattern in which the transparent conductive film and the light-shielding conductive film are laminated without misalignment is formed in the central windows on both sides of the base sheet, and the outer frame on both sides of the base sheet. Forming a thin-line-drawing circuit pattern in which the transparent conductive film and the light-shielding conductive film are laminated without misalignment. Therefore, since an elaborate and fine thin line drawing circuit pattern can be formed, there is an effect that a touch input sheet having a very narrow frame can be manufactured.

  In addition, since the light-shielding conductive film is formed under the first photoresist layer, when the first photoresist layer is patterned by a method such as exposure on both sides at the same time, the light beam of the exposure is on the opposite side of the first photo layer. The resist layer can be prevented from reaching, and the patterning of the first photoresist layer on one side does not affect the patterning of the first photoresist layer on the opposite side. Therefore, there is an effect that a touch input sheet in which the circuit pattern and the thin line drawing circuit pattern are formed on both surfaces of the base sheet can be manufactured with high productivity and high quality. In addition, since the transparent conductive film is exposed by removing the light-shielding conductive film of the electrode pattern at each central window, visibility of the touch input sheet can be ensured.

  In addition, although the light-shielding conductivity remains in the thin line drawing circuit pattern, the light-shielding conductivity of the terminal portion is removed to expose the transparent conductive film, and the portions other than the terminal portion are covered with a rust prevention functional film. . Therefore, the thin wire drawing circuit pattern has a low resistance maintained for a long time by covering the two-layer structure of the transparent conductive film and the light-shielding conductive film with a rust preventive functional film except for the terminal part, and in the terminal part. The electrical connection with the FPC is maintained by removing the light-shielding conductive film.

It is a figure explaining an electrode pattern and a thin line drawing circuit pattern about one Example of the touch input sheet which concerns on this invention. It is sectional drawing which shows the example of the touch input sheet | seat in which an electrode pattern and a thin wire drawing circuit pattern are formed in both surfaces of the transparent base material sheet | seat which consists of one resin sheet. FIG. 3 is a partial enlarged cross-sectional view showing a vicinity A of a terminal portion of the touch input sheet of FIG. 2. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is sectional drawing which shows the process of manufacturing the touch input sheet | seat of FIG. It is a top view explaining an example of the shape and arrangement | positioning aspect of the electrode pattern formed in the center window part of a film sensor. It is a figure for demonstrating the electrode formation process of the touch input device of patent document 1. FIG. It is a partial expanded sectional view which shows the example which the light-shielding electrically conductive film exposed in the terminal part. It is a partial expanded sectional view which shows the example which provided the conformal coat from the top connected with FPC.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram for explaining an electrode pattern and a thin line drawing circuit pattern in one embodiment of the touch input sheet according to the present invention. FIG. 2 is a cross-sectional view showing an example of a touch input sheet in which an electrode pattern and a thin line drawing circuit pattern are formed on both surfaces of a transparent substrate sheet made of a single resin sheet, and FIG. 3 is a touch input sheet of FIG. It is a partial expanded sectional view which shows the terminal part vicinity A of this. 4A to 4K are cross-sectional views illustrating steps for manufacturing the touch input sheet of FIG. In the figure, 1 is a touch input sheet, 6 is a base sheet, 7 is a central window part, 8 is an outer frame part, 9 is a transparent conductive film, 10 is an electrode pattern, 11 is a thin line drawing circuit pattern, and 12 is a light-shielding conductive film. , 13 is a terminal portion, 14 is a rust prevention functional film, 16 is a first photoresist layer, 17 is a mask, 18 is a second photoresist layer, 19 is a mask, 28 is a third photoresist layer, 29 is a mask, Reference numeral 32 denotes an exposure light beam.

  In the touch input sheet 1 shown in FIG. 1 and FIG. 2, the electrode pattern 9 made of only the transparent conductive film 3 is formed on the central window portions 24 on both sides of the base sheet, and the transparent conductive film 3 and the light-shielding conductive film are formed on the outer frame portion 22. 1 is a touch input sheet on which a thin line drawing circuit pattern 10 in which 1 is sequentially laminated is formed, and the transparent conductive film 3 and the light-shielding conductive film 1 of the thin line drawing circuit pattern 10 are laminated in a pattern having the same width without misalignment. Is formed.

  The method for manufacturing the touch input sheet 5 in which the circuit pattern of the transparent conductive film 3 and the thin line drawing circuit pattern 10 are formed on both surfaces is firstly formed on both surfaces of the transparent base sheet 6 made of a single resin sheet. After obtaining a conductive film in which a transparent conductive film 9, a light-shielding conductive film 12, and a first photoresist layer 16 were sequentially laminated (see FIG. 4A), a mask 17 having a desired pattern was placed on each of the front and back sides. The first photoresist layer 16 is patterned by exposure (see FIG. 4B) and development. At this time, since the light-shielding conductive film 1 blocks the exposure light beam 32 on the opposite surface, even if it is simultaneously exposed with a different mask pattern, the pattern on the opposite first photoresist layer 16 is not affected. Therefore, since both sides can be exposed simultaneously, the front and back of the first photoresist layer 16 can be easily aligned, and both sides can be patterned in a single process, and the productivity is improved. Note that the position of the mask 17 shown in FIG. 4B is the case where the first photoresist layer 16 is a negative type (when exposed, the solubility in the developer is lowered and the exposed portion remains after development). Show. In the case of the positive type (when exposed, the solubility in the developer increases and the exposed portion is removed), the portion shielded from light by the mask is reversed.

  Next, the transparent conductive film 9 and the light-shielding conductive film 12 are simultaneously etched with an etchant such as ferric chloride, and the portion of the transparent conductive film 9 and the light-shielding property where the patterned first photoresist layer 16 is not stacked. By removing the conductive film 12, the electrode pattern 10 in which the transparent conductive film 9 and the light-shielding conductive film 12 are laminated without misalignment is formed in the central window portions 7 on both surfaces of the base sheet 6. A thin line drawing circuit pattern 11 in which the transparent conductive film 9 and the light-shielding conductive film 12 are laminated without misalignment is formed on each of the outer frame portions 8 (see FIG. 4C).

  Incidentally, the base sheet 6 has a problem of elongation. Therefore, the patterning of the first photoresist layer 16 on both sides of the conductive film is suitably performed by double-sided simultaneous exposure. This is because when the patterning of the first photoresist layer 16 is performed by exposing one side at a time, the patterning on one side is completed, and when the base sheet is stretched when the conductive sheet is replaced with the front and back of the exposure apparatus, This is because the circuit pattern on the front surface and the circuit pattern on the back surface are displaced. In the case of the example shown in FIGS. 1 and 5, since the positional relationship between the rhombus electrode 46 and the rhombus electrode 47 is complementary, if the circuit pattern on the front surface and the circuit pattern on the back surface are displaced, the capacitance type It will not function correctly as a touch sensor.

  In the present invention, since the light-shielding conductive film 12 blocks the exposure light beam 32 on the opposite surface during exposure, the pattern of the first photoresist layer 16 on the opposite side is affected even if exposure is performed simultaneously with a different mask pattern. Does not affect. Therefore, since both sides can be exposed simultaneously, the front and back of the first photoresist layer 16 can be easily aligned, and both sides can be patterned in a single process, and the productivity is improved.

  In addition, the well-known mask alignment method of a double-sided exposure apparatus can be used for alignment of a front mask and a back mask. For example, a mask alignment mark is formed on each of the front mask and the back mask, and an optical reading sensor such as a camera reads the overlapping state of the pair of mask alignment marks, thereby relative to the front mask and the back mask. Get location information. Then, based on the obtained position information, the mask position adjusting mechanism relatively moves the front mask and the back mask so that the pair of mask alignment marks overlap with each other. For example, a method of aligning the back mask.

  After the above-described etching, the first photoresist layer 16 is stripped with a resist stripping solution, and a second photoresist layer 18 is formed on the entire surface on the surface on which the electrode pattern 10 and the thin line drawing circuit pattern 11 are formed. (See FIG. 4D) After that, the mask 19 is placed, exposed (see FIG. 4E) and developed to pattern the second photoresist layer 18 (see FIG. 4F). The position of the mask 19 shown in FIG. 4 (e) is the case where the second photoresist layer 18 is a negative type (when exposed, the solubility in the developer is lowered and the exposed portion remains after development). Show.

  Next, etching is performed with a special etching solution such as acidified hydrogen peroxide, and only the light-shielding conductive film 9 where the patterned second photoresist layer 18 is not stacked is removed, so that both surfaces of the base sheet are removed. The transparent conductive film 39 is exposed at each of the central window portion 7 and the terminal portion 13 in the outer frame portion 8 (see FIG. 4G).

  If the transparent conductive film 9 is an amorphous material, it is preferably crystallized by a method such as heat treatment before the etching. This is because the etching resistance is improved by crystallization, and only the light-shielding metal film 12 can be easily etched selectively.

  Next, the second photoresist layer 18 is stripped with a resist stripper to expose the light-shielding conductive film 9 (see FIG. 4 (h)), and then a rust preventive function so as to cover the exposed light-shielding conductive film 9. A film 14 was formed (see FIG. 4 (k)). Therefore, the thin wire routing circuit pattern 11 has a low resistance maintained for a long time by covering the two-layer structure of the transparent conductive film 9 and the light-shielding conductive film 12 with the rust preventive functional film 14 except for the terminal portion 13. In addition, in the terminal portion 13, the electrical connectivity with the FPC 40 is maintained by removing the light-shielding conductive film 12.

  The above rust prevention will be described in more detail. If the product is not covered with the rust prevention functional film 14, the corrosive liquid from the outside after the product is completed, such as sweat liquid or salt water, or an environment such as high temperature and high humidity. Under the test, corrosion of the light-shielding conductive film 12 of the thin line drawing circuit pattern 11 proceeds, resulting in a problem that electrical characteristics deteriorate. On the other hand, if it is covered with the anti-corrosion function film 14 as in the present invention, even if corrosive liquid enters from the outside after completion of the product, or under environmental tests such as high temperature and high humidity. Corrosion does not progress in the routing circuit and electrical characteristics can be maintained. Therefore, the present invention can be sufficiently applied to an application in which the drawing circuit is a thin line and needs to maintain a low resistance over a long period of time, like a touch input sheet applied to a capacitive touch sensor or the like. Further, since the terminal part 13 cannot be covered with the FPC 40 when covered with the rust preventive functional film 14, it cannot be covered with the rust preventive functional film 14, and the light shielding conductive film of the terminal part 13 is left as it is. Will be corroded (see FIG. 7). For this reason, the conformal coat 60 is required after being connected to the FPC 40 (see FIG. 8), and the manufacturing cost is high because labor and materials are required accordingly. However, in the case of the present invention, the light-shielding conductive film 12 of the terminal portion 13 is also removed using etching in the process of removing the light-shielding conductive film 12 of the electrode pattern, and the transparent conductive film 9 that is resistant to corrosion is exposed. Rust prevention of the terminal part 13 can also be aimed at without incurring manufacturing cost.

  In addition, as a formation method of the antirust function film | membrane 14, the method formed by a photo process is employable. That is, the second photoresist layer 18 is stripped with a resist stripping solution to expose the light-shielding conductive film 9 (see FIG. 4H), and then the surface on which the electrode pattern 10 and the thin line drawing circuit pattern 11 are formed. A third photoresist layer 28 is entirely formed on the entire surface (see FIG. 4 (i)), and then a mask 29 is placed, exposed (see FIG. 4 (j)) and developed to form the third photoresist layer 28. Patterning was performed so as to cover the light-shielding conductive film 9, and this was used as the anti-rust function film 14 (see FIG. 4 (k)). Note that the position of the mask 29 shown in FIG. 4 (j) is the case where the third photoresist layer 28 is a negative type (when exposed, the solubility in the developing solution decreases, and the exposed portion remains after development). Show.

  Further, as a method of forming the rust prevention functional film 14, it may be formed by a printing method. That is, the second photoresist layer 18 is stripped with a resist stripping solution to expose the light-shielding conductive film 9 (see FIG. 4H), and then the rust-proofing function so as to cover the exposed light-shielding conductive film 9 The film 14 is printed (see FIG. 4 (k)).

  When the end portions of the thin line drawing circuit pattern 11 formed on both surfaces of the touch input sheet 1 obtained by the above method are connected to the FPC 40 at the terminal portions 13, respectively, the transparent conductive film 9 is formed with the base sheet 6 interposed therebetween. A capacitive touch sensor having the electrode pattern 10 formed on both sides is manufactured.

  Here, the electrode pattern 9 formed in the central window portion 7 of the touch input 1 will be supplementarily described. The electrode pattern 9 has different patterns on the front and back sides. For example, as shown in FIG. 5, on the back surface of the base sheet 6, a rhombus electrode 46 having a rhombus shape in plan view, and a connection wiring 469 penetrating a plurality of rhombus electrodes 46 in the vertical direction (Y direction) in the figure. And. The plurality of rhombus electrodes 46 and the connection wiring 469 are electrically connected to each other. Further, such a connection wiring 469 and a plurality of rhombus electrodes 46 penetrating therethrough are taken as a set, and the set is repeatedly arranged in the horizontal direction (X direction) in the drawing. On the other hand, in the same manner, a plurality of rhombus electrodes 47 and connection wirings 479 penetrating them are provided on the surface of the base sheet 6. However, in this case, the extending direction of the connection wiring 479 is different from that of the connection wiring 469 in the horizontal direction (X direction) in the drawing. Along with this, the direction in which a set of the connection wiring 479 and the plurality of rhombus electrodes 47 penetrating the connection wiring 479 is repeatedly arranged is the vertical direction (Y direction) in the drawing. As is apparent from FIG. 5, the rhombus electrode 46 is disposed so as to fill the gaps between the plurality of connection wirings 479, while the rhombus electrode 47 is disposed so as to fill the gaps between the plurality of connection wirings 469. Is done. Further, in FIG. 5, the positional relationship between the diamond electrode 46 and the diamond electrode 47 is complementary. That is, the plurality of rhombus electrodes 47 are arranged so as to fill in the rhombus-shaped gaps that occur when the rhombus electrodes 46 are arranged in a matrix.

  As described above, the X direction electrode and the Y direction electrode are arranged so as to form a lattice in plan view, so that if a user's finger or the like touches any position on the lattice (for example, a dotted circle FR) ), A capacitor is formed between the finger and the X-direction electrode touched by the finger, and a capacitor is formed between the finger and the Y-direction electrode touched by the finger. By forming this capacitor, the capacitance of the X direction electrode and the Y direction electrode increases. The position detector of the external circuit detects the amount of change in capacitance that occurs in such a case, or even the X-direction electrode and Y-direction electrode having the maximum capacitance, and touches anywhere in the central window portion 7. Can be acquired as a set of an X coordinate value and a Y coordinate value as a specific value.

  Next, each layer forming the touch input sheet 1 will be described in detail.

  First, the base sheet 6 is made of a transparent resin sheet having a thickness of about 30 to 2000 μm, and the material is polyester resin, polystyrene resin, olefin resin, polybutylene terephthalate resin, polycarbonate resin, acrylic resin, or the like. The plastic film etc. are mentioned.

  The transparent conductive film 9 may be a layer made of a metal oxide such as indium tin oxide or zinc oxide, and may be formed by a vacuum deposition method, a sputtering method, an ion plating method, a plating method, or the like. The film is formed with a thickness of about several tens to several hundreds of nanometers, and is easily etched together with the light-shielding conductive film 12 in a solution such as ferric chloride, but the light-shielding conductive film 12 such as hydrogen peroxide solution in an acidic atmosphere. It must be not easily etched with an etchant. And it is preferable to show a light transmittance of 80% or more and a surface resistance value of several mΩ to several hundred Ω. The transparent conductive film 9 may be a conductive polymer film such as thiophene, or a conductive fiber film including metal nanowires or carbon nanotubes. In that case, the transparent conductive film 9 may be formed by various printing methods or painting.

  Examples of the light-shielding conductive film 12 include a single metal film having high conductivity and good light-shielding properties, and a layer made of an alloy or a compound thereof, such as a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. It is good to form by. It is also necessary that an etchant exists that is not etched by the transparent conductive film 9 but is etched by the light-shielding conductive film 12 itself. Examples of the preferable metal include aluminum, nickel, copper, silver, and tin. In particular, a metal film made of copper foil having a thickness of 20 to 1000 nm is excellent in electrical conductivity and light shielding properties, and the transparent conductive film 9 can be easily etched with hydrogen peroxide in an acidic atmosphere that is not etched. It is very preferable because it has ease of use. More preferably, the thickness is 30 nm or more. More preferably, it is good to set it as 100-500 nm. This is because a highly conductive light-shielding conductive film 12 can be obtained by setting the thickness to 100 nm or more, and a light-shielding conductive film 12 that is easy to handle and excellent in workability can be obtained by setting the thickness to 500 nm or less.

  The first photoresist layer 16 is made of an acrylic photoresist material having a thickness of 10 to 20 μm, which can be developed with an alkaline solution or the like by exposure with a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a laser beam or a metal halide lamp. This is because the thin line drawing circuit pattern 11 with a narrow line width can be formed with high reliability by exposure and development with a photoresist material, and the touch input sheet 1 with a narrower frame can be manufactured. The first photoresist layer 16 may be formed by a general printing method such as gravure, screen, and offset, as well as by various coater methods, coating and dipping methods, and various methods such as a dry film resist method. Although patterning may be performed by exposure and development, the dry film resist method is more preferable.

  The dry film resist (DFR) used in the dry film resist method is a film in which a photosensitive layer that becomes the first photoresist layer 16 is sandwiched between a base film and a cover film. The above printing method, coating method, painting method, etc. have problems such as only one side coating and poor efficiency, whereas the dry film resist method bonds the photosensitive layer with a heating roll after peeling the cover film. This method is mainstream because it is highly productive and can meet various requirements. The exposure is usually performed by placing a mask on the base film (not shown), and development is performed after the base film is peeled off. As the base film of the dry film resist, a film made of polyethylene terephthalate or the like can be used. Moreover, what consists of polyethylene etc. can be used as a cover film of a dry film resist.

  The material and the formation method of the second photoresist layer 18 can be the same material and the formation method as the first photoresist layer 16.

  When the rust prevention functional film 14 is formed by a photo process, the same photoresist material as that of the first photoresist layer 16 in which a rust preventive agent is added is used as the third photoresist layer 28 or the above-described photoresist material. It is preferable to use a material having excellent rust prevention property as the third photoresist layer 28. Further, the method for forming the third photoresist layer 28 can be the same as the method for forming the first photoresist layer 16. Moreover, when the antirust function film | membrane 14 is based on a printing method, it is good to form using the ink containing an antirust agent. As the rust preventive agent, materials that are already known as rust preventive agents are used. As specific examples, for example, imidazole, triazole, benzotriazole, benzimidazole, benzthiazole, pyrazole and the like may be used. In addition, monocyclic or polycyclic azoles such as halogen, alkyl, and phenyl-substituted products, aromatic amines such as aniline, aliphatic amines such as alkylamine, salts thereof, and the like. There is no need to be limited to the materials described herein.

  As mentioned above, although one Example of the touch input sheet was described, this invention is not limited to this. For example, the base sheet 6 is not limited to the one constituted by a single plastic film as illustrated, and a plurality of plastic films may be stacked to form a laminate as the base sheet 6. In this case, as a plastic film laminating means, thermal lamination, dry lamination via an adhesive layer, or the like can be used. When a plastic film is laminated with an adhesive layer, the thickness of the entire laminate can be adjusted by using an adhesive layer having a core material. The plastic film may be laminated at any timing after the transparent conductive film 9 is formed on the plastic film, after the light-shielding conductive film 12 is laminated, or after the first photoresist layer 16 is laminated.

Example 1
A colorless polyester film having a thickness of 200 μm unwound from a roll is used as a base sheet, a transparent conductive film is formed with a thickness of 200 nm by sputtering made of indium tin oxide, and a copper film is formed thereon as a light-shielding conductive film Was formed by sputtering to a thickness of 500 nm to prepare a conductive film. Next, after laminating a set of conductive films using a transparent adhesive to obtain a laminate in which a transparent conductive film and a light-shielding conductive film are laminated on both sides, a negative type that can be developed with a 1% caustic soda solution. Using a dry film resist provided with an acrylic photosensitive layer, a first photoresist layer having a thickness of 10 nm is formed on both sides of the laminate, and a mask having an X-direction electrode pattern is placed on the front side, A mask having an electrode pattern in the Y direction was placed on the back side, and both the front and back surfaces were exposed simultaneously by a metal halide lamp, and developed by immersion in a 1% caustic soda solution.

  Next, the portion of the indium tin oxide film and the copper film where the patterned first photoresist layer is not laminated is simultaneously etched away with an etching solution of ferric chloride. Is an electrode pattern in the X direction, and a Y direction electrode pattern is exposed on the back side, and a thin line drawing pattern with an average line width of 20 μm is exposed on both the front and back surfaces on the outer frame surrounding the central window. It had been.

  Next, after peeling off the first photoresist layer, a 10 nm thick second photoresist layer is formed on both surfaces using a dry film resist that can be developed with 1% caustic soda solution and has a negative acrylic photosensitive layer. Then, a mask was placed on the outer frame portion excluding the terminal portions on the front and back sides, and both the front and back surfaces were exposed simultaneously with a metal halide lamp, and developed by immersion in 1% caustic soda solution.

  Next, the exposed copper film in the central window that was exposed when immersed in hydrogen peroxide in an acidic atmosphere was etched away, leaving only the indium tin oxide film formed therebelow.

  Next, after peeling off the second photoresist layer, a dry film resist having a negative acrylic photosensitive layer that can be developed with a 1% caustic soda solution and benzoimidar is added as a rust inhibitor is used. A 10 nm third photoresist layer is formed on both sides, and a mask is placed on the outer frame except for the terminal part. Both sides are exposed with a metal halide lamp and exposed to 1% caustic soda solution. The remaining third photoresist layer was used as a rust prevention functional layer.

Example 2
A touch input sheet was obtained by the same method as in Example 1 except that the rust prevention functional layer was formed by direct patterning by screen printing using a rust prevention ink instead of a photo process.

  By the method of Example 1 or Example 2, only the indium tin oxide film having the X-direction electrode pattern and the Y-direction electrode pattern is formed on the both sides of the base sheet in the central window portion, and the outer frame portion is formed on each outer frame portion. Is a thin wire routing circuit in which a copper film is formed on the indium tin oxide film except for the terminal portion, and a touch input sheet is obtained in which the thin wire routing circuit is covered with a rust prevention functional film except for the terminal portion. It was. When the end of the thin line drawing circuit pattern formed on the touch input sheet is connected to the FPC and evaluated as to operate as a capacitive touch sensor, both the first and second embodiments are good. Results were obtained, and even if corrosive liquid from the outside entered after the product was completed, or the circuit was not corroded under environmental tests such as high temperature and high humidity, the electrical characteristics could be maintained. .

  The present invention is an invention of a method for manufacturing a touch input sheet that can be applied to an input device such as a mobile phone, a PDA, a small PC, or the like that is provided with a video screen such as a liquid crystal panel.

DESCRIPTION OF SYMBOLS 1 Touch input sheet 6 Base sheet 7 Central window part 8 Outer frame part 9 Transparent conductive film 10 Electrode pattern 11 Thin wire drawing circuit pattern 12 Light-shielding conductive film 13 Terminal part 14 Rust prevention functional film 16 First photoresist layer 17 Mask 18 First Two photoresist layers 19 Mask 28 Third photoresist layer 29 Mask 32 Exposure light 40 FPC
60 Conformal coat 46, 47 Diamond electrode 469.479 Connection wiring

Claims (4)

A step of obtaining a conductive film in which a transparent conductive film, a light-shielding conductive film, and a first photoresist layer are sequentially laminated on both sides of a transparent substrate sheet,
Partially exposing the first photoresist layer on both sides simultaneously and developing each pattern by developing; and
By simultaneously etching and removing the transparent conductive film and the light-shielding conductive film in the portion where the patterned first photoresist layer is not laminated, the transparent conductive film and the light-shielding are respectively formed in the central window portions on both sides of the base sheet. Forming an electrode pattern in which the conductive film is laminated without misalignment, and forming a thin line drawing circuit pattern in which the transparent conductive film and the light-shielding conductive film are laminated without misalignment on the outer frame portions on both sides of the base sheet. When,
After peeling off the first photoresist layer, a step of laminating a second photoresist layer on the entire surface on which the electrode pattern and the fine line drawing circuit pattern are formed;
Partially exposing the second photoresist layer on both sides simultaneously and developing each pattern by developing; and
By etching away only the light-shielding conductive film in the portion where the patterned second photoresist layer is not laminated, the transparent conductive film is exposed at the central window portion and the terminal portion on both sides of the base sheet. A process of
And a step of coating the exposed light-shielding conductive film with a rust-proofing functional film after peeling off the second photoresist layer. A method for producing a touch input sheet having excellent rust-proofing characteristics.   The manufacturing method of the touch input sheet | seat excellent in the rust prevention property of Claim 1 whose said rust prevention functional film is formed of the printing method.   The manufacturing method of the touch input sheet | seat excellent in the rust prevention property of Claim 1 whose said rust prevention functional film is formed of the photo process.   The manufacturing method of the touch input sheet | seat excellent in the rust prevention property in any one of Claims 1-3 whose said transparent conductive film is an ITO film | membrane and the said light-shielding conductive film is a copper foil.

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