JPS597174B2 - Manufacturing method of keyboard for electronic desk calculator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a keyboard for an electronic desktop calculator, and particularly an electronic keyboard that does not require the incorporation of a spacer as in conventional products, has excellent electrical conductivity, and has excellent durability. The present invention relates to five manufacturing methods for a desktop computer keyboard.

The keyboard of conventional electronic desk calculators is made up of a conductive layer area on the back side of buttons for numbers, letters, symbols, etc., and a printed circuit board for electronic desk calculators that forms the corresponding desired contact points. requires the incorporation of a flexible intermediate insulating sheet, i.e., a spacer, having a thickness of 50 to 300 microns with openings corresponding to the conductive layer areas;
This makes the assembly process long and complicated.

Additionally, the openings in the spacer must be precisely manufactured, resulting in high costs. The present invention has been made in order to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a method for manufacturing a keyboard for an electronic desktop calculator that is highly durable using relatively simple processes and materials.

In the present invention, first, (a) graphite with a particle size of 0.1 to 60 μ is applied to the back surface 1b of a flexible insulating substrate film 1 such as a transparent polyester film, polyamide film, or polycarbonate film with a thickness of 15 to 150 μ. powder,
20 to 80% by weight of conductive fine powder consisting of one or more of silver powder and carbon black powder with a particle size of 0.1 μ or less, and (b) 1 of chloroprene rubber, chlorosulfonated rubber, polyurethane resin, and polyester resin. species or two
Rubber-based and thermoplastic resin-based binders consisting of 5 to 3 species
0% by weight and (c) 15 to 80% by weight of a solvent such as dimethylformamide, dimethylacetamide, isoborone, diethyl carbitol, butyl carbitol, and turpentine oil are mixed (a + mouth + c) and dissolved uniformly. Using a suspension paint with an apparent specific gravity of 0.9 to 1.9 and a viscosity of 150 to 1200 poise, a circular, elliptical, or Screen or gravure printing is performed on a polygon, etc. to a thickness of 10 to 50μ, and the printed surface is heated at a temperature of 80 to 150℃ for 10 to 30 minutes.
The film is heated and dried for 0 minutes to form an insulating substrate film 1 provided with conductive layer areas 2 (Step A).

In this case, the flexible insulating substrate film 1 may be made of natural or synthetic rubber, polypropylene, polyvinyl chloride, etc., in addition to those described above, but if the thickness is less than 15 μm, its strength There is a problem with durability, and if it exceeds 150μ, it is unnecessary in terms of strength and durability, and preferably 15 to 150μ. In addition, in the composition of the suspension paint (a + mouth + c), if the quantity limitations in the composition of graphite, silver powder and carbon black exceed the upper and lower limits of 20 to 80% by weight, The stability of the suspension paint used for printing and the so-called "glue" and "consistency" of printability are both poor, especially below the lower limit, the conductivity of the film is extremely poor and it no longer has the properties as a conductor. If it exceeds this, the adhesive strength will deteriorate and it is not possible.

Regarding particle size, in the case of graphite and silver powder, if the particle size exceeds 60μ, the stability of the suspension paint and the so-called "glue" of printing will deteriorate, sufficient adhesion will not be obtained, and printing performance will be poor. Therefore, conductivity deteriorates and it is not possible.

Further, if the lower limit is less than 0.1μ, it is usually not commercially available and is inappropriate in view of the viscosity consistency and printability of the suspension. In the case of carbon black powder, the particle size is set to 0.1μ or less because particles with a particle size exceeding 0.1μ are normally impossible to make manually, and in the case of carbon black, the particle size is set to 0.1μ or less by using the graphite This is because, unlike silver powder, the particles are bonded together like a chain, so even if the particles are fine, they are suitable for printing. Next, as the thermoplastic adhesive binder, the chloroprene rubber is, for example, Neoprene WR manufactured by Showa Neoprene Co., Ltd.
Examples of chlorosulfonated rubbers such as TsWD include Hypalonya 30 and 40 manufactured by DuPont; examples of ethylene-vinyl acetate copolymer resins include Flowback D-5010 manufactured by Steel Chemical Co.; and polyurethane resins such as For example, examples of polyester resins include Paraprene 22S and 25S manufactured by Nippon Polyurethane Co., Ltd., and Byronya 20 manufactured by Toyobo Co., Ltd.
0,300 etc. can be used.

However, if the quantity of rubber-based and thermoplastic resin-based binders is limited, that is, below the lower limit of 5 to 30% by weight, the dispersion stability of the suspension and the "glue" of printing will be poor and the consistency will be poor. If the upper limit is exceeded, the density is too high and the printability becomes even worse.
This is not possible because the conductivity will be significantly deteriorated. To prepare the above-mentioned suspension, the above composition raw materials (a), (b), and (c) are mixed in predetermined amounts (a + mouth + c), dissolved, and dispersed to give an apparent specific gravity of 0.9 to 1.9. , a suspension paint having a viscosity of 150 to 1200 poise is prepared. If the apparent specific gravity of the suspension paint produced in this case is less than 0.9, the conductivity will be poor as a result of a lack of fine powder components such as graphite, silver, and carbon black, and if it exceeds 1.9, the apparent specific gravity of the liquid will be poor. Dispersibility deteriorates,
Stability will be impaired and adhesive strength will deteriorate, so it is not acceptable. Regarding the viscosity, if it is less than the lower limit, the printability will be poor, and if it exceeds the upper limit, the dispersibility of the liquid will be poor and the printability will be even worse, which is unacceptable.

Next, the coating thickness of this suspension paint is limited, that is, 10
The reason for setting the value to ~50μ is that it is used to open and close the contacts that send signals, so if it is less than 10μ, there is a risk that the contact will not be sufficient when pressing numbers or other keys, etc., and the signal will not be sent reliably. . On the other hand, the reason why the upper limit is set to 50μ is that a thickness greater than this is unnecessary to reliably transmit signals. With the above steps, 6 steps are completed. Next, with respect to the part of the back surface 1b of the insulating substrate film obtained in the step 6 excluding each conductive layer area 2, leaving a small width of the film material around the conductive area 2 or not leaving it at all, (a) 30 to 99.9% by weight of a rubber-based and resin-based adhesive consisting of one or more of silicone resin, polyester resin, polyurethane resin, and silicone rubber, and (b) toluene, xylene, isoboron, and dimethylformamide. , mixed with 0.1 to 70% by weight of a solvent such as butyl carbitol (a+b
) Dissolved apparent specific gravity 0.9-1.3, viscosity 150
~2000 poise insulation paint with thickness 80~300
Screen or gravure printing is performed on μ, and the printed surface is heated and dried at a temperature of 50 to 150° C. for 5 to 30 minutes to form an insulating layer 3 serving as a spacer on the back side 1b of the insulating substrate film.

In this case, as the resin-based and rubber-based insulating adhesive, the silicone resin may be, for example, manufactured by Toray Silicone Co., Ltd. under the trade name SEl7Ol, SH85O, SHl8.
Examples of polyester resins include Byron Black 200 and Black 3000 manufactured by Toyobo Co., Ltd.; examples of polyurethane resins include Paraprene 22S and 25S manufactured by Nippon Polyurethane Co., Ltd.; examples of silicone rubbers include: Torre. Products such as SEl7lO, SH9583, SH9585 manufactured by Silicone Co., Ltd. can be used.

However, if the quantity of the rubber-based or resin-based insulating adhesive is limited, that is, if the amount is less than the lower limit of 30 to 100% by weight, printing will not be good, the consistency will be insufficient, and the printability will not be good. Further, the upper limit is set to 100% by weight because silicone resin and silicone rubber are solvent-free paints with good printability. Next, the reason for limiting the coating thickness of this insulating paint, that is, 80 to 300μ, is that
If it is less than 80μ, it is not possible because there is a risk that it will not function as the intermediate insulating layer 3.

That is, even if the insulating substrate film surface 1a is not pressed, there is a risk that the conductive layer portion 2 and the contacts 7 on the lower printed circuit board 6 will be electrically connected. If it exceeds 300μ, on the other hand, it is not possible to operate unless it is pressed downward very strongly.

This limit is actually preferred. This completes the 8th process.
Next, the insulating paint (a+b) is applied to the front surface 1a of the insulating substrate film in a circular, elliptical, polygonal, etc. shape at a position corresponding to each conductive layer area 2 on the back surface 1b of the insulating substrate film with a thickness of 100 to 100 mm. Screen or gravure printing is performed on 500μ, and the printed surface is heated and dried at a temperature of 50 to 150°C for 5 to 30 minutes to form an insulating layer that serves as a direct pushbutton for numbers, letters, symbols, etc., or an intermediate signal transmission layer from the pushbutton. Form layer 4 (step C).

In this case, the coating thickness of the insulating paint is limited, i.e. 100~
The reason for setting the thickness to 500μ is that if it is less than 100μ, the function as a push button will be inadequate and the conductive layer portion and the contact on the lower printed circuit board will not be electrically connected.

Further, the reason why the upper limit is set to 500 μm is because, from a practical point of view, the push button does not need to be thicker than this.
With the above steps, the step (C) is completed. Finally, each conductive layer area 2 on the back surface 1b of the substrate film 5 formed in step (C) is
It is placed on each contact portion 7 of the corresponding desired electronic desk calculator printed circuit board 6, and the push button board 8 is further placed on top of it, and the three parts (5, 6, 8) are fixed together (D process).

That is, a so-called pushbutton board 8, such as an aluminum plate or a stainless steel plate, on which numbers, letters, symbols, etc. are shown is placed so as to correspond to the insulating layer area 4 on the surface 1a of the substrate film 5, and a desired display is pressed. Alternatively, each contact portion 7 of the printed circuit board 6 is opened and closed by releasing the contact portion 7 of the printed circuit board 6. By combining the above steps (A), 8, (C), and 9, a method for manufacturing a keyboard for an electronic desktop calculator according to the present invention is provided. The strength of the pressure to activate the keyboard by pressing it with your fingertips, etc., the return speed, etc. will depend on the material and thickness of the flexible insulating substrate film 1, and the conductive suspension printed on the back side 1b. The coating film made of suspension paint and its thickness, each insulating layer (3, 4) and its thickness made of coating film made of insulating paint printed on both sides (1b and 1a), and the conductive layer 2 printed on the back side. The selection is determined by size, shape, etc.

The electronic desk calculator keyboard according to the present invention has excellent durability, flexibility, and perfect signal transmission and disconnection, and is fully guaranteed for practical use. In addition, it is possible to eliminate the process of assembling a spacer, which is currently performed when assembling an electronic desktop calculator, which is rational.
In addition, substantially the same results were obtained by partially changing the order of the steps (O step→(4) step→(B) step→9 steps).

Example 1 To the back surface 1b of a polyester substrate film 1 with a thickness of 50μ, (a) 30% by weight of graphite powder with a particle size of 0.1 to 60μ and 5% by weight of carbon black with a particle size of 0.1μ or less, and (b) 25% by weight of polyurethane resin, namely Paraprene 22S (trade name, manufactured by Nippon Polyurethane Co., Ltd.);
(c) A suspension paint consisting of 40% by weight of isoboron (a + mouth + c) was applied to a printed circuit board 6 for an electronic desktop calculator.
It was printed in a circular shape with a thickness of 15 μm using a screen printing method on the positions corresponding to each contact portion 7, and dried at a temperature of 100° C.

Thus, on the back side 1b of the polyester substrate film 1,
The conductive layer area 2 was formed using the suspension paint [Step 6]. Next, on the back side 1b of the polyester substrate film 1 excluding the conductive layer area 2, a small portion of the film fabric around the conductive area is left, and (a) silicone rubber, ie, toray is applied. Manufactured by Silicone Co., Ltd. Product name SEl7
An insulating paint containing 10 and 100% by weight was printed to a thickness of 100 μm by screen printing and cured by heating at a temperature of 120° C.

Thus, an insulating layer 3 serving as a spacer is formed on the back side 1b of the polyester substrate film 1 except for the conductive layer area 2.
was formed [step (8)]. Next, using the silicone rubber, the surface 1a of the polyester substrate film 1 is
, a circular shape with a thickness of 10 at a position corresponding to the conductive area 2
Printed by screen printing method at 0μ, temperature 120℃
It was heated and cured.

Thus, on the surface 1a of the polyester substrate film 1,
An insulating layer area 4 serving as a button was formed at a position corresponding to the conductive layer area 2 on the back surface 1b [step (C)]. Next, each conductive layer area 2 on the back surface 1b of the polyester substrate film 5 obtained in step O is placed on each contact portion 7 of the corresponding desired printed circuit board 6 for an electronic desktop calculator, Furthermore, an aluminum plate 8 with numbers, letters, symbols, etc. indicated on it is placed so as to correspond to the insulating layer area 4 on the surface 1a of the polyester film substrate 5, and the three parts (8, 5, 6) are fixed together. Step 9].

The keyboard thus obtained has excellent durability,
Signal transmission and disconnection were perfect.

In addition, substantially the same results were obtained when chloroprene rubber, chlorosulfonated rubber, polyester resin, etc. were used instead of the polyurethane resin. Also, substantially the same results were obtained when silicone resin, polyurethane resin, or polyester resin was used instead of the silicone rubber. In addition, substantially the same results were obtained even when the insulating layer 3 was formed without leaving any film material around the conductive area 2 in the 8 steps. Example 2 On the back surface 1b of a polyester substrate film 1 with a thickness of 35μ, (a) 20% by weight of graphite powder with a particle size of 0.1 to 60μ and 20% by weight of silver powder with a particle size of 0.1 to 60μ; ) polyurethane resin, i.e., trade name Paraprene 22S, manufactured by Nippon Polyurethane Co., Ltd., 20% by weight, and (c)
Suspension paint consisting of 40% by weight of isoboron (i + mouth +
C) was printed in a circular shape with a thickness of 20 μm by screen printing on the position corresponding to each contact portion 7 of the printed circuit board 6 for an electronic desktop calculator, and dried at a temperature of 100° C.

Thus, the conductive layer area 2 was formed on the back surface 1b of the polyester substrate film 1 using the suspension paint [Step 6].
o Next, on the back side 1b of the polyester substrate film 1 excluding the conductive layer area 2, leaving a small portion of the film fabric around the conductive area, (a) silicone rubber, ie, Toray. Manufactured by Silicone Co., Ltd. Product name: SH958
3. A 100% by weight insulating paint was printed to a thickness of 120μ by screen printing, and cured by heating at a temperature of 120°C.

Thus, an insulating layer 3 serving as a spacer is formed on the back side 1b of the polyester substrate film 1 except for the conductive layer area 2.
was formed [Step 8]. Next, using the silicone rubber, on the surface 1a of the polyester substrate film 1,
A circular shape with a thickness of 150μ is placed at a position corresponding to the conductive area 2.
The film was printed using a screen printing method and cured by heating at a temperature of 120°C.

Thus, on the surface 1a of the polyester substrate film 1,
An insulating layer area 4 serving as a button was formed at a position corresponding to the conductive layer area 2 on the back side 1b [Step (C)] o Next, the back side 1b of the polyester substrate film 5 obtained in step (C) Each of the conductive layer areas 2 is placed on each contact portion 7 of the corresponding desired printed circuit board 6 for an electronic desktop calculator, and the conductive layer areas 2 are placed on the respective contact portions 7 of the corresponding desired printed circuit board 6 for an electronic desktop calculator so as to correspond to the insulating layer area 4 of the surface 1a of the polyester substrate film 5. The aluminum plate 8 with numbers, letters, symbols, etc. indicated on it is placed and the three parts (8, 5, 6) are fixed together [Step 9] o The keyboard thus obtained is highly durable and has excellent signal strength. Transmission and disconnection were perfect.

Note that instead of the polyurethane resin, chloroprene rubber,
Almost similar results were obtained using chlorosulfonated rubber and polyester resin. Also, substantially the same results were obtained when silicone resin, polyurethane resin, or polyester resin was used instead of the silicone rubber. Example 3 On the back side 1b of a polyester substrate film 1 with a thickness of 75μ, (a) 35% by weight of graphite powder with a particle size of 0.1 to 60μ and 7% by weight of carbon black with a particle size of 0.1μ or less, and (b) A suspension paint (a + mouth + c) consisting of chloroprene rubber, namely neoprene WRT2O (trade name manufactured by Showa Neoprene Co., Ltd., trade name: % by weight) and (iii) 38% by weight of isoboron, was applied to a printed circuit board 6 for an electronic desktop calculator. It was printed in a circle with a thickness of 15 μm at positions corresponding to each contact portion 7 using a screen printing method, and dried at a temperature of 100° C.

In this way, the conductive layer area 2 made of the suspension paint was formed on the back surface 1b of the polyester substrate 1 [Step 6]. Next, the conductive layer area 2 on the back side 1b of the polyester substrate film 1
(a) Silicone resin, ie, Toray. Manufactured by Silicone Co., Ltd. Product name SEl7Ol, lO
An insulating paint containing 0% by weight was printed to a thickness of 100 μm by screen printing and cured by heating at a temperature of 100° C.

In this way, the insulating layer 3 serving as a spacer was formed on the back surface 1b of the polyester substrate film 1 except for the conductive layer area 2 [Step 8]. Next, the silicone resin is applied to the surface 1a of the polyester substrate film 1 in a circular pattern with a thickness of 200 mm at a position corresponding to the conductive layer area 2.
It was printed using a screen printing method and cured by heating at a temperature of 100°C.

Thus, on the surface 1a of the polyester substrate film 1,
An insulating layer area 4 serving as a button was formed at a position corresponding to the conductive layer area 2 on the back surface 1b [step (O)].Next, (
The conductive layer areas 2 on the back surface 1b of the polyester substrate film 5 obtained in step C) are placed on the corresponding contact portions 7 of the desired electronic desk calculator printed circuit board 6, and the polyester An aluminum plate 8 on which numbers, letters, symbols, etc. are indicated is placed so as to correspond to the insulating layer area 4 on the surface 1a of the substrate film 5, and the three parts (8, 5, 6) are fixed together [Step 9 ].

The keyboard thus obtained has excellent durability,
Signal transmission and disconnection were perfect. In addition, substantially the same results were obtained when chlorosulfonated rubber, polyurethane resin, or polyester resin was used instead of the chloroprene rubber. Also, silicone rubber instead of the silicone resin,
Almost similar results were obtained using polyurethane resin and polyester resin. In addition, substantially the same results were obtained even when the insulating layer 3 was formed without leaving any film material around the conductive area 2 in step (2). Example 4 Back surface 1b of polyester substrate film 1 with a thickness of 120μ
(a) 25% by weight of graphite powder with a particle size of 0.1 to 60μ and 4% by weight of carbon black with a particle size of 0.1μ or less
(b) A suspension paint (a + mouth + c) consisting of 40.21% by weight of chlorosulfonated rubber, 40.21% by weight of Hypalon Black manufactured by DuPont, and (c) 50% by weight of isoboron. Each contact part 7 of the computer printed circuit board 6
It was printed in a circular shape with a thickness of 40'' by screen printing at a position corresponding to , and dried at a temperature of 100°C.

In this way, the conductive layer area 2 made of the suspension paint was formed on the back surface 1b of the polyester substrate film 1 [Step 6]
]. Next, with respect to the back side 1b of the polyester substrate film 1 excluding the conductive layer area 2, leave a small portion of the film fabric around the conductive area, and (a) use a polyester resin, that is, a polyester resin (trade name: Vyro manufactured by Toyobo Co., Ltd.). Z factory 300,
40% by weight and (b) 60% by weight of isoborone are mixed (
a+b) The melted insulating paint was printed to a thickness of 200μ by screen printing and dried at a temperature of 100°C. Thus, an insulating layer 3 serving as a spacer is formed on the back side 1b of the polyester substrate film 1 except for the conductive layer area 2.
was formed [Step 8]. Next, the insulation paint (a+b)
The surface 1a of the polyester substrate film 1 is
, a circular shape with a thickness of 25 is formed at a position corresponding to the conductive layer area 2.
Printing was performed using a screen printing method at 0μ and dried at a temperature of 100°C.

In this way, an insulating layer area serving as a button was formed on the front surface 1a of the polyester substrate film 1 at a position corresponding to the conductive layer area 2 on the back surface 1b [step (O)].Next, in Examples 1 to 3, Three people (8, 5, 6) in roughly the same way
) Fixing them together [Step 9] o The keyboard thus obtained had excellent durability, and signal transmission and disconnection were perfect.

In addition, substantially the same results were obtained when chloroprene rubber, polyurethane resin, or polyester resin was used instead of the chlorosulfonated rubber. Also, substantially the same results were obtained when silicone rubber, silicone resin, or polyurethane resin was used instead of the polyester resin. Example 5 To the back surface 1b of a polyester substrate film 1 with a thickness of 15μ, (a) 25% by weight of graphite powder with a particle size of 0.1 to 60μ and 10% by weight of silver powder with a particle size of 0.1 to 60μ, and further with a particle size of 0. 5% by weight of carbon black of 1μ or less, (b)
A suspension paint (a + mouth + c) consisting of polyester resin, namely, Toyobo Co., Ltd. trade name Byron Black 300.20% by weight and (c) 40% by weight of isoboron, was printed for an electronic desktop calculator. A circular pattern with a thickness of 15 μm was printed on a position corresponding to each contact portion 7 of the circuit board 6 using a screen printing method, and dried at a temperature of 100° C.

In this way, the conductive layer area 2 was formed on the back surface 1b of the polyester substrate film 1 by the suspension paint [step (
4)]. Next, with respect to the back side 1b of the polyester substrate film 1 excluding the conductive layer area 2, leaving a small portion of the film fabric around the conductive area, (a) polyurethane resin, i.e., a product name manufactured by Nippon Polyurethane Co., Ltd. An insulating paint made by mixing (a+b) 35% by weight of paraprene 25S and (b) 65% by weight of isoboron was coated to a thickness of 100%.
It was printed using a screen printing method and dried at a temperature of 110°C. In this way, the insulating layer 3 serving as a spacer was formed on the back surface 1b of the polyester substrate film 1 except for the conductive layer area 2 [Step 8]. Next, using the insulating paint (a+b), it was printed on the surface 1a of the polyester substrate film 1 in a circular shape with a thickness of 100 μm at a position corresponding to the conductive layer area 2 by screen printing at a temperature of 110°C. It was dried.

In this way, an insulating layer area serving as a button was formed on the front surface 1a of the polyester substrate film 1 at a position corresponding to the conductive layer area 2 on the back surface 1b [step (0)].Next, in Examples 1 to 3, Three people (8, 5, 6) in roughly the same way
) Fixing them together [Step 9] o The keyboard thus obtained had excellent durability, and signal transmission and disconnection were perfect.

In addition, substantially the same results were obtained when chloroprene rubber, chlorosulfonated rubber, or polyurethane resin was used instead of the polyester resin. Also, substantially the same results were obtained when silicone rubber, silicone resin, or polyester resin was used instead of the polyurethane resin. In addition, substantially the same results were obtained even when the insulating layer 3 was formed without leaving any film material around the conductive area 2 in the 8 steps.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a flexible insulating substrate film according to the present invention, FIG. 2a is a perspective view showing the conductive layer area formed on the back side of the substrate film by step A, and FIG. 2b is a perspective view of the same. FIG. 3a is a schematic cross-sectional view taken along the Eero line, and FIG. The figure is a perspective view showing the surface of the substrate film with an insulating layer area formed on the surface of the substrate film by step C, FIG. FIG. 6 is a schematic perspective view of a printed circuit board for a computer, and FIG. 6 is a schematic cross-sectional view showing a keyboard for an electronic desktop computer according to an embodiment of the present invention. 1...Transparent flexible insulating substrate film, 1a.
...Surface of insulating substrate film, 1b...
Back side of insulating substrate film, 2... Back conductive layer area, 3... Back insulating layer, 4... Front insulating layer area, 5... (C ) A substrate film formed in the process, 6...Electronic desk calculator printed circuit board, 7... Contact portion of printed circuit board, 8
...Push button board.

Claims (1)

[Claims] 1. A) graphite powder with a particle size of 0.1 to 60μ, silver powder and a particle size of 0.1 to 60μ on the back side of a transparent flexible insulating substrate film.
20 to 80% by weight of conductive fine powder consisting of one or more types of carbon black powder of 1 μ or less, and (b) one or more types of chloroprene rubber, chlorosulfonated rubber, polyurethane resin, and polyester resin. 5 to 30% by weight of a rubber-based and thermoplastic resin binder, and (c)
Dimethylformamide, dimethylacetamide, isophorone, diethyl carbitol, butyl carbitol, and 15 to 80% by weight of a solvent such as turpentine are mixed (a+b+c) and uniformly dispersed with an apparent specific gravity of 0.9 to 80% by weight.
1.9, using a suspension paint with a viscosity of 150 to 1200 poise, paint a circular, elliptical, polygonal, etc. shape with a thickness of 10 poise on the position corresponding to each contact point of a printed circuit board for an electronic desk calculator.
Step (A) of screen or gravure printing on ~50 μm and drying to form an insulating substrate film provided with conductive layer areas, and applying the conductive layer to a portion of the insulating substrate film excluding the conductive layer areas. (a) A rubber-based and resin-based insulating adhesive 30 to 30 consisting of one or more of silicone resin, polyester resin, polyurethane resin, and silicone rubber, with a small width or no film fabric remaining around the area. (a+
b) Dissolved apparent specific gravity 0.9-1.3, viscosity 15
Using insulating paint of 0 to 2000 poise, thickness 80 to 3
Screen or gravure printing on 00μ and drying process (
B) and the insulating paint (a+b) are used to form circles and ellipses on the surface of the insulating substrate film at positions corresponding to the respective conductive layer areas on the back surface of the insulating substrate film formed in step (A). , step (C) of screen or gravure printing to a thickness of 100 to 500 μm in a polygonal shape, etc. and drying, and further, each conductive layer area on the back surface of the substrate film formed in step (C) is step (D) of placing a pushbutton board having numbers, letters, symbols, etc. on each contact point of the printed circuit board for an electronic desktop calculator and fixing the three parts together; A method for manufacturing a keyboard for an electronic desktop calculator, characterized by comprising: 2 The transparent flexible insulating substrate film has a thickness of 15 to 150 mm.
A method for manufacturing a keyboard for an electronic desk calculator according to claim 1, characterized in that the keyboard is made of μ polyester film, polyamide film, polycarbonate film, polypropylene film, polyvinyl chloride film, natural and synthetic rubber film, etc. .