JPH0325886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planar switch used in keyboard switches and the like.

Conventional planar switches of this type are shown in Figures 1 and 2.
As shown in the figure, a sheet-shaped plastic spacer 5 with holes 5a formed at the positions of the electrodes 3 and 4 is interposed between the upper circuit film 1 and the lower circuit film 2. The upper and lower electrodes 3 and 4 were separated, the elastic electrode portion of the upper circuit film 1 was pressed to bring the upper and lower electrodes 3 and 4 into conduction, and the upper and lower electrodes 3 and 4 were then released and shriveled. According to the configuration of this surface switch, it is possible to easily obtain a keyboard switch having a large number of electrical contacts, but on the other hand, since the spacer 5 is interposed, it is difficult to manufacture the spacer 5 itself and the position of the spacer 5. The work of assembling the surface switch while aligning the parts is complicated, and the cost is high.

Furthermore, as shown in FIG. 2, there is also a surface switch in which the electrode 3 on the upper circuit film 1 side is provided in a recess 1a formed in the upper circuit film 1. , a spacer is required to prevent the lower leader lines from being shot at their intersections, and the above-mentioned drawbacks still remain.

The present invention was developed in view of the above circumstances, and it is an object of the present invention to provide a simple surface switch that does not require a conventional spacer and can be manufactured efficiently and at low cost.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a circuit diagram as an example of a surface switch constituting a keyboard matrix. In this circuit, the upper electrode side is shown by a solid line, and the lower electrode side is shown by a broken line.

FIG. 4 is a cross-sectional view taken along the - line in FIG. Plastic plates having a thickness of about 0.5 to 5 mm are used, and are made of materials such as vinyl chloride resin, polycarbonate, polyphenylene oxide, semi-cured epoxy resin laminates, and semi-cured phenolic resin laminates.

An upper electrode 12 and an upper lead wire 13 from the upper electrode 12 are formed in a thin layer on the surface of the upper electrode support film 10, and the upper circuit film 1
It has become 4.

Further, on the lower electrode supporting plate 11, a lower electrode 15 at a position corresponding to the upper electrode 12 on the upper circuit film 14 and a lower lead wire 16 from the lower electrode 15 are similarly formed in a thin layer to form a lower circuit. The lower electrode 15 and the lower leader wire 16 are connected to the lower electrode recess 18 formed in the lower electrode support plate 11 and the lower leader wire recess 1.
Each exists on the bottom of 9.

A method for manufacturing the lower circuit board 17 will be described.

First, the lower electrode support plate 11 is molded by a cast molding method. That is, the above-mentioned vinyl chloride resin, polycarbonate, polyphenylene oxide, etc. was liquefied into a casting mold that was made to form a plate with concave portions where the lower electrode and lower lead wire were to be placed. A lower electrode support plate 11 having a lower electrode recess 18 and a lower leader wire recess 19 is formed by injecting liquid resin.

Next, the lower electrode recess 1 of this lower electrode plate 11
8 and the bottom of the lower leader line recess 19, the lower electrode 15 and the lower leader line 16 are formed in a thin layer using metal foil or conductive ink. For example, there are the following three methods. . In the first method, as shown in FIG. 7, a wide metal foil 20 is placed on the lower electrode support plate 11, and a protrusion in the pattern of the lower electrode and the lower leader line is formed on the edge of the metal foil 20. This is a die stamp method in which the metal foil 20 is punched out in a pattern of lower electrodes and leader lines by pressing with a die stamp blade 21, and at the same time, the edges of the metal foil 20 are inserted into the bottoms of the recesses 18 and 19 and crimped. After pressing, when the metal foil is peeled off, the circuits of the lower electrode and the lower lead wire remain at the bottoms of the recesses 18 and 19, and the other parts are removed.

In the second method, as shown in FIG. 8, a circuit foil 23 made of metal foil is formed on an adhesive sheet 22 in a pattern of lower electrodes and lower leader lines, and an adhesive is applied to the surface of the circuit foil 23. is applied to the concave portions 18 and 19 of the lower electrode support plate 11 to form a convex shape 2.
This is a transfer method in which the circuit foil 23 is bonded to the bottoms of the recesses 18 and 19 by pressing down with a step 4. In addition, the adhesive sheet 22
The circuit 23 is peeled off after being transferred.

The third method is to use a convex type 2 with a circuit pattern of a lower electrode and a lower leader line, as shown in FIG.
5 is coated with a conductive paint 26 by screen printing or the like, this convex mold 25 is pressed against the recesses 18 and 19 of the lower electrode support plate 11, and a conductive paint circuit is printed on the bottom of the recesses 18 and 19. .

Still another method of manufacturing the lower circuit board 17 will be described.

First, the lower electrode support plate 11 is molded by injection molding. That is, the aforementioned synthetic resin such as vinyl chloride resin, polycarbonate, polyphenylene oxide, etc. is heated and melted in the cylinder of an injection molding machine to form a fluid state, and a recess is formed in the area where the lower electrode and lower lead wire are to be placed. The fluidized synthetic resin is injected at high pressure into a mold that is made to form a plate body with A lower circuit board 17 having a line recess 19 is formed. Next, the lower electrode 15 and the lower leader line 16 are formed in a thin layer on the bottom of the lower electrode recess 18 and the lower leader line recess 19 of the lower circuit board 17 using metal foil or conductive ink.

In the surface switch configured as above,
When you press the electrode part of the upper circuit film 14 with your finger, the upper electrode support film 10 bends, causing the upper electrode 12 and the lower electrode 15 to come into contact, making this contact conductive. When you release your finger, the upper electrode support film Since 10 has elasticity, it can be restored to form the upper electrode 1.
2 separates from the lower electrode 15, this contact is briefly broken, thus ensuring conduction and breaking operations as a keyboard switch.

As explained above, the switch according to the present invention includes an upper circuit film in which electrodes and lead wires are formed in a thin layer on the surface of an elastic plastic film, and electrodes and lead wires in recesses provided in a plastic plate. Since the lower circuit board formed in a thin layer is directly stacked, there is no need for spacers to separate the upper and lower electrodes and lead wires as in conventional surface switches, and a surface switch with a simple structure can be obtained. Therefore, it is possible to manufacture this surface switch efficiently and at low cost. According to the method of the present invention, for example, the conductor formed in a predetermined pattern on the base is pressed by the convex part and pushed into the concave part, thereby performing processes such as peeling from the base and cutting off the margin part. A circuit pattern is formed within the recess and further fixed by a pressing force. Therefore, a complex circuit pattern consisting of a contact portion and a connection portion can be formed by a simpler process and with better workability than when the circuit pattern is directly formed on the recess side. Efficiently manufacture surface switches,
Moreover, it has the effect that it can be realized at low cost.

[Brief explanation of drawings]

Fig. 1A is a sectional view of the main part of a conventional surface switch, B is a plan view of the main part of the spacer, Fig. 2 is a sectional view of the main part of another conventional surface switch, and Figs. 3 is a circuit diagram of a surface switch, FIG. 4 is a sectional view taken along the - line in FIG. 3, FIG. 5 is a sectional view taken along the - line in FIG. 4, and FIG. 4, FIG. 7, FIG. 8, and FIG. 9 are explanatory diagrams of a method for forming a circuit in the recess after forming a recess in the lower electrode support plate. DESCRIPTION OF SYMBOLS 10... Upper electrode support film, 11... Lower electrode support plate, 12... Upper electrode, 13... Upper leader line, 14... Upper circuit film, 15... Lower electrode, 16... Lower leader line, 17 ... lower circuit board, 18 ... lower electrode recess, 19 ... lower leader wire recess.

Claims (1)

[Claims] 1. Forming a lower electrode support plate having a planar recess formed on one side corresponding to a circuit pattern consisting of an electrode and a leader line from the electrode, and forming a conductor constituting the circuit pattern to correspond to the recess. The circuit pattern consisting of the electrode part and the leader line part is pressed down with a mold having a convex part in a flat planar shape, and the circuit pattern consisting of the electrode part and the leader line part is brought into close contact with the bottom of the recess part. A side circuit board is formed, and electrodes corresponding to the electrodes of the lower circuit board and lead wires from the electrodes are formed in a thin layer on the surface of this lower circuit board and a flat elastic upper electrode supporting film. A method for manufacturing a surface switch characterized by directly overlapping a circuit film.