JPH08258147A - Production of embossed sheet - Google Patents

Abstract

PURPOSE: To enhance the productivity and heat resistance of an embossed sheet and to enable the long-term preservation and use thereof by pressing the predetermined position of an insulating resin sheet by the leading end part of a heated rod-shaped molded element and subsequently cooling the sheet to apply emboss processing to the same. CONSTITUTION: Perforations are preliminarily provided to the lower mold plate 9 held on a stand 11 so as to be matched with emboss arranging patterns and guide grooves 11a, 11b are provided to both side ends of the stand 11 to provide a moving stand 13 freely movable in an X-direction. A guide groove 13a is provided to the moving stand 13 to make a holder 15 freely movable in a Y- direction and a rod-shaped element 1 is held to the holder 15 so as to be movable in a Z-direction and a heating coil is built in the rod-shaped molded element 1. The rod-shaped molded element 1 is heated by a heater 3 to be pressed to a PET sheet 7. At this time, since the perforations are provided to the lower mold plate 9, the PET sheet 7 is molded so as to form protruding parts on the underside of the sheet. Next, heating is stopped and cooling air of a cooling air supply device 5 is blown against the sheet from a blowoff nozzle 5a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an embossed sheet used in a membrane switch, which is one of thin switches in electronic equipment and the like.

[0002]

2. Description of the Related Art A membrane switch is known as a thin switch input device for electronic equipment. The most general type of this membrane switch has a structure composed of a counter electrode and a spacer, and there is a membrane switch in which a click plate (metal dome) is provided above the counter electrode portion for the purpose of giving a click feeling.

In such a membrane switch, the contact portion of the upper electrode sheet is embossed (convex).
By doing so, there is a so-called embossed switch having characteristics such as a click feeling, deletion of constituent members, and stable switch operation (no inversion failure occurs).

In such an embossing switch, as shown in FIG. 6, first, a pair of molding dies including a concave embossing upper die 31 and a convex embossing lower die 33 is used, and a cushion sheet 35 is provided between these dies. And the PET sheet 37. Next, as shown in FIG. 7, heating and pressurization are held for several minutes to perform press working (hot pressing step). further,
As shown in FIG. 8, cooling and pressurization are held for several minutes for press working (cold press step). In this way, the convex shape of the mold is transferred onto the sheet to manufacture (FIG. 9).
reference).

Next, the structure of a membrane switch using an embossed sheet will be described with reference to the sectional view shown in FIG. An insulating layer 43 is provided on the upper side surface of the printed board 41. An embossed sheet 37 that has been embossed is disposed on the upper side of the insulating layer 43. The embossed sheet 37 is arranged so that the convex portion 37 a faces the pair of electrodes 53. A counter electrode 51 is provided on the inner side surface of the convex portion 37a. On the embossed sheet 37, an insulating layer 45 having an opening 45a aligned with the protrusion 37a is joined. A flexible surface sheet 47 is provided on the insulating layer 45.

In the membrane switch thus constructed, when a portion of the surface sheet 47 corresponding to the convex portion 37a is pushed with a finger or the like, the convex portion 37a is deformed, the top thereof is dented, and the counter electrode 51 is paired. Contact the electrode 53 of. As a result, the pair of electrodes 53 are electrically connected to each other via the counter electrode 51. In this case, a click feeling is obtained when the convex portion 37a is deformed. When the finger or the like is released from the surface sheet 47, the convex portion 37a returns to the initial state by the elastic force, and the pair of electrodes 53 is electrically separated.

The membrane switch using this embossed sheet has the advantages that the number of constituent members can be reduced, the manufacturing cost can be reduced, and inversion failure hardly occurs and the switch operation is stable.

As described above, the conventional embossed sheet for a membrane switch is formed by molding a flat insulating resin sheet with a hot press machine heated to a high temperature, holding it for a certain period of time, and then pressing it with a cold press machine. Being manufactured. There is also a method of embossing a sheet only with a cold press machine without using a hot press machine.

[0009]

However, the method for producing an embossed sheet through both the hot pressing step and the cold pressing step has the advantage that the characteristic deterioration of the embossed sheet due to the high temperature is small, but the heat transfer to the sheet. In addition, since it is necessary to hold the sheet in a pressed state for a certain period of time in the hot pressing process, there is a drawback that productivity is poor. On the other hand, the method of embossing a sheet with only a cold press machine has good productivity because it does not require holding time, but when the embossed sheet is stored or used at high temperature for a long time, the shape of the convex portion changes. Then, there is a drawback that characteristics such as elasticity are deteriorated. Therefore, the embossed sheet produced only by the cold press machine is difficult to store and use for a long period of time, and its application is limited to use in an apparatus that is not exposed to high temperature.

Further, in the above-mentioned conventional method, the accuracy of the convex shape of the embossing die affects the product characteristics. Therefore, the higher the precision required for the die, the higher the die cost. Also, since the entire mold is heated and cooled, the heat efficiency is poor and the molding time is long, and pressure and heat treatment are applied to parts other than the embossed part, so other members (spacer sheet, etc.)
There is also a problem that it is difficult to perform the pressing work in the state where they are attached.

Further, when the heat-resistant type embossing is formed by the conventional method, it is necessary to extend the forming time or to add a step of performing heat treatment (annealing) again after forming.

The present invention has been made in view of the above problems, and is for a membrane switch capable of producing an embossed sheet which has excellent productivity, excellent heat resistance and can be stored and used for a long period of time. An object is to provide a method for manufacturing an embossed sheet.

[0013]

In order to achieve the above object, the present invention is to manufacture an embossed sheet used in a membrane switch in which a click feeling is imparted by embossing a pressing portion of an insulating resin sheet. In the method, an embossing process is performed by pressing a predetermined position of the insulating resin sheet with the tip of the heated rod-shaped molded body and then cooling. Preferably, the rod-shaped molded body is configured to be movable along the surface of the insulating resin sheet. More preferably, a plurality of rod-shaped molded bodies may be provided.

[0014]

In the method for producing an embossed sheet according to the present invention, first, a predetermined position of the insulating resin sheet is pressed by the tip portion of the heated rod-shaped molded body, and thereafter, the sheet is cooled and embossed. As a result, an embossed sheet with a click feeling can be manufactured with high productivity without requiring a mold.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the configuration of an embossed sheet manufacturing apparatus to which the method for manufacturing an embossed sheet according to the present invention is applied.

First, the structure of the embossed sheet manufacturing apparatus 10 will be described with reference to FIG. The gantry 11 holds the lower mold plate 9 on its upper surface substantially horizontally. Holes 9a as shown in FIG. 2 are provided in advance in the lower mold plate 9 in alignment with the embossing arrangement (formation) pattern. Further, guide grooves 11a and guide grooves 11b are provided at both ends of the gantry 11, and the guide grooves 11a and 11b are used to interpose X and Y in the figure.
The movable rack 13 is configured to be movable in any direction.
The movable rack 13 is provided with a guide groove 13a,
A support tool (not shown) is fitted into the guide groove 13a, and the holder 15 is supported via the support tool so as to be movable in the Y direction in the drawing.

The holder 15 has a rod-shaped molded body 1
Are held so that they can move in the Z direction in the figure. A heating coil 3a is built in the rod-shaped molded body 1 (heating pin). At this time, by increasing the heat generation amount of the heating coil 3a and decreasing the heat capacity of the rod-shaped molded body 1, even if the rod-shaped molded body 1 is moved down and pressed immediately before being pressed against the PET sheet 7, the rod-shaped molded body is instantly pressed. The tip portion of No. 1 can be heated to a predetermined temperature and can be cooled promptly.

With the above-mentioned structure, the rod-shaped molded body 1 can be freely moved in the XY plane and embossed at any position. Further, the holding body 15 is provided with a blowing nozzle 5a for blowing the cooling air supplied from the cooling air supply device 5 toward the tip of the rod-shaped molded body 1. Further, the heating device 3 and the heating coil 3a, the cooling air supply device 5 and the blowing nozzle 5a are connected by a power cable 3b and a tube 5b formed in a spiral shape.

Next, the manufacturing procedure in this embodiment will be described with reference to FIGS. First, the rod-shaped molded body 1 is attached to the holding body 15, and the moving rack 13 and the holding body 15 are moved to a predetermined position, that is, a position where the PET sheet 7 is embossed by a control unit (not shown).

The control unit may be individually controlled by a personal computer or the like, or may be centrally managed by factory automation (FA). Furthermore, for example, in a prototype, the operation switches provided in the embossed sheet manufacturing apparatus 10 may be manually operated individually.

Next, the rod-shaped molded body 1 is energized and heated.
Then, after reaching a temperature sufficient for molding, the rod-shaped molded body 1 is lowered and pressed against the PET sheet 7. At this time, since the lower mold plate 9 is provided with the holes 9a, the PET sheet 7 is molded so as to be convex downward. Next, while maintaining the heating state of the rod-shaped molded body 1,
Hold under pressure (see FIG. 3). At this time, immediately before the rod-shaped molded body 1 is lowered and pressed against the PET sheet 7, electricity may be applied to instantaneously heat the tip portion of the rod-shaped molded body 1 to a predetermined temperature.

Next, the heating of the rod-shaped molded body 1 is stopped (however, the pressurization is continued), the cooling air from the cooling air supply device 5 is blown out from the blowing nozzle 5a, and the tip of the rod-shaped molded body 1 is applied for several seconds. The rod-shaped molded body 1 is raised, and the blowing of cooling air is also stopped. As a result, a convex embossment 7a is formed at the position of the penetrating portion 9a of the lower die plate 9 of the PET sheet 7, and the embossed sheet is manufactured (see FIG. 5).

As described above, in this embodiment, the heated rod-shaped molded body 1 is pressed against only the required portion of the convex shape (embossed shape), and the emboss is molded by heating, pressurizing and cooling. It is a thing.

In this embodiment, only one rod-shaped molded body 1 is provided on the holding body 15. However, by providing a plurality of rod-shaped molded bodies 1, a plurality of embossments can be molded at the same time by one movement of the holding body 15. It will be possible. At this time, by stopping the driving of any rod-shaped molded body 1, the embossed portion can be quickly formed in any pattern. For example, by providing the holder 15 alone with the four rod-shaped molded bodies 1,
It is possible to form four embossed portions at the same time by driving once, and by driving only one or two rod-shaped molded bodies 1 out of the four rod-shaped molded bodies 1 to an arbitrary position. The embossed portion can be quickly formed.

As described above, according to the present embodiment, it is possible to perform embossing only with a plurality of rod-shaped molded bodies and a lower die plate provided with holes, and an expensive die for embossing becomes unnecessary. Further, since the rod-shaped molded body having the same shape is embossed, the switch characteristics are stable. That is, in the upper and lower mold methods, it is necessary to form a convex shape for each key, and variations in shape may affect variations in switch characteristics. Further, since a press machine adapted to the size of the mold is not required and only the rod-shaped molded body needs to be pressurized, a low pressure is required, and a compact and simple facility can be used. ◎

Furthermore, since each key can be molded in a few seconds, the molding cycle can be shortened, and embossing can be performed even when a spacer sheet or the like is attached.

[0027]

As described above, according to the present invention, an embossed sheet having excellent heat resistance and capable of being stored and used for a long period of time can be produced with high productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embossed sheet manufacturing apparatus to which an embossed sheet manufacturing method according to the present invention is applied.

FIG. 2 is a diagram illustrating a method for manufacturing an embossed sheet according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a method for manufacturing an embossed sheet according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating a method for manufacturing an embossed sheet according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a method for manufacturing an embossed sheet according to an example of the present invention.

FIG. 6 is a diagram showing a manufacturing procedure of a conventional embossed sheet.

FIG. 7 is a diagram showing a manufacturing procedure of a conventional embossed sheet.

FIG. 8 is a diagram showing a manufacturing procedure of a conventional embossed sheet.

FIG. 9 is a diagram showing a manufacturing procedure of a conventional embossed sheet.

FIG. 10 is a diagram showing a configuration of a membrane switch.

[Explanation of symbols]

 1 bar-shaped molded body 3 heating device 3a heating coil 5 cooling air supply device 5a blowing nozzle 7 PET sheet 7a embossing part 9 lower die plate 9a hole 10 embossing sheet manufacturing device 11 mount 11a, 11b guide groove 13 moving frame 13a guide groove 15 holding Body 31 Embossing upper mold 33 Embossing lower mold 35 Cushion sheet 37 PET sheet 37a Convex portion 41 Printed circuit board 43, 45 Insulating layer 47 Surface sheet 51 Counter electrode 53 Electrode pair

Claims (3)

[Claims] 1. A method of manufacturing an embossed sheet used in a membrane switch, wherein a pressing feeling is imparted by embossing a pressing portion of an insulating resin sheet, wherein the tip portion of a heated rod-shaped body is A method for manufacturing an embossed sheet, which comprises embossing by pressing a predetermined position of an insulating resin sheet and then cooling. 2. The method for manufacturing an embossed sheet according to claim 1, wherein the rod-shaped molded body is provided so as to be movable along the surface of the insulating resin sheet. 3. The method for manufacturing an embossed sheet according to claim 1, wherein a plurality of the rod-shaped molded bodies are provided.