JPH041969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a transparent conductive sheet.
More specifically, the present invention relates to a method for producing a transparent conductive sheet that can be used as a constituent material for precision electrical equipment such as digital contact input tablets.

[Prior Art] In a transparent pressure-sensitive conductive sheet for a digital contact type input tablet, it is desirable that the embedded conductor be as thin and as thin as possible. However, with conventional manufacturing methods, the diameter of the embedded conductor is
It was 0.3mm or more. That is, in the conventional manufacturing method,
It is difficult to provide a large number of recessed lines on a transparent sheet and embed extremely thin conductors onto the recessed lines. Note that this recessed portion constitutes a gap between the contacts when used as an electrical contact.

[Problems to be Solved by the Invention] The present invention has been made based on this point, and its purpose is to provide a method for manufacturing a transparent conductive sheet that is extremely thin and has extremely thin conductors embedded therein. The goal is to provide the following.

[Means for Solving the Problems] The gist of the present invention is as follows: (a) A photosensitive polymer layer is provided on a base sheet, and a metal foil layer is provided on the photosensitive polymer layer. There is a composite sheet consisting of a composite sheet, and a step of applying a masking layer to a portion of the composite sheet that will become a conductive portion of the metal foil layer, and then etching the masked portion; (c) forming a skeletal conductor by pasting a masking layer around the conductive part left on the polymer layer by etching, and then irradiating and eluting the masked part; (c) converting the skeletal conductor into a transparent liquid; (d) After irradiating the photosensitive polymer layer of the embedded skeletal conductor, the photosensitive polymer layer and the base sheet layer are eluted; A method of manufacturing a transparent conductive sheet for electrical contacts, comprising the steps of: , removing the sheet.

In the present invention, a metal sheet, a plastic sheet, a glass plate, etc. are used as the base sheet. A positive resist is suitable as the photosensitive polymer layer.

In the present invention, the metal foil includes aluminum foil,
Copper foil, silver foil, gold foil, metal vapor deposition film, etc. can be used. In the present invention, the liquid polymer material may be any material that is liquid at room temperature and cures by adding a catalyst or heating to form a transparent sheet, such as transparent liquid silicone rubber, transparent polyurethane rubber, Examples include liquid bolybdadiene, liquid epoxy resin, and unsaturated polyester resin.

[Function] The effect of the present invention is to smoothly and orderly embed an extremely thin and extremely fine conductor obtained by etching a special composite sheet into a transparent liquid polymer material. Furthermore, the recessed portions for configuring the gaps between the conductors necessary as electrical contacts can be formed in any shape. Therefore, when two of the obtained transparent conductive sheets are combined and used for an input doublet, etc., it is possible to perform input operations that are easy to see and highly accurate.

[Example] Next, an example of the method for manufacturing a transparent conductive sheet of the present invention will be described with reference to the drawings.

1 to 5 are explanatory diagrams showing one embodiment of the method for manufacturing a transparent conductive sheet of the present invention, and FIG.
The figure is a plan view thereof.

In Figures 1 to 6, 1 is the base material, 2 is the photosensitive polymer, 2' is the remaining part of the photosensitive polymer layer that has been irradiated and eluted, 3 is the metal foil, and 3' is the etched metal foil. The conductor 4 obtained by the treatment is a transparent polymer sheet.

In Figure 1, a photosensitive polymer positive resist is applied to a thickness of 0.3 mm on a transparent glass plate 1 as a base material, and the upper layer is coated with a transparent adhesive material to a thickness of 0.3 mm.
This shows a composite sheet made by bonding 0.05mm copper foil. Figure 2 shows the width of the composite sheet shown in Figure 1 after masking and etching the metal foil layer.
The conductor 3' is 0.1 mm thick. FIG. 3 shows the photosensitive polymer layer of the conductor-attached composite sheet of FIG. 2 subjected to masking, irradiation, and elution treatments to form a skeletal conductor.

Figure 4 shows a transparent liquid silicone rubber poured into the skeletal conductor shown in Figure 3 from above and heated and molded at 120°C for 60 minutes.

FIG. 5 shows a transparent conductive sheet obtained by irradiating, eluting and removing the base material 1 and the remaining portion 2' of the photosensitive polymer layer of the molded product shown in FIG. Note that it is desirable that the surface of the conductor be plated with a noble metal if necessary. In FIG. 5, the thickness of the transparent sheet is 0.7 mm, and the recess is 3 mm wide and 0.3 mm deep. Further, the conductor has a width of 0.1 mm and a thickness of 0.05 mm.

[Effect of the invention] According to the method for manufacturing a transparent conductive sheet of the present invention,
A transparent conductive sheet embedded with extremely thin and extremely thin conductors can be easily produced and is industrially useful.

[Brief explanation of drawings]

In Figure 1, a photosensitive polymer positive resist is applied to a thickness of 0.3 mm on a transparent glass plate 1 as a base material, and the upper layer is coated with a transparent adhesive material to a thickness of 0.3 mm.
A cross-sectional view showing a composite sheet made by adhering 0.05 mm copper foil. Figure 2 shows the metal foil layer of the composite sheet in Figure 1 which has been masked and etched to a width of 0.1 mm.
Figure 3 is a cross-sectional view of a skeletal conductor obtained by masking, irradiation, and elution treatment of the photosensitive polymer layer of the conductor-attached composite sheet of Figure 2. Figure 4 is a cross-sectional view of the molded product obtained by pouring transparent liquid silicone rubber from the top of the skeletal conductor shown in Figure 3 and heating and molding it at 120°C for 60 minutes, and Figure 5 is a cross-sectional view of the molded product shown in Figure 4. FIG. 6 is a cross-sectional view of a transparent conductive sheet obtained by irradiating, eluting, and removing the base material 1 and the photosensitive polymer remaining portion 2', and FIG. 6 is a plan view thereof. 1: Base material, 2: Photosensitive polymer, 3: Metal foil,
4: Transparent polymer.

Claims (1)

[Scope of Claims] 1 (a) There is a composite sheet in which a photosensitive polymer layer is provided on a base sheet, a metal foil layer is provided on the upper layer of the photosensitive polymer layer, and the outer composite sheet is After applying a masking layer to the part of the metal foil layer that will become the conductive part, etching the part to be masked; (b) removing the conductive part left on the photosensitive polymer layer of the composite sheet by etching; After pasting a masking layer around the periphery, the non-masking portion is irradiated and eluted to form a skeletal conductor; (c) The skeletal conductor is embedded and molded with a transparent liquid polymer material to form an embedded skeletal conductor. (d) After irradiating the photosensitive polymer layer of the embedded skeletal conductor, the photosensitive polymer layer and the base sheet layer are eluted and removed. A method for producing a transparent conductive sheet for electrical contacts.