JPS59209225A - Diaphragm switch unit and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm switch device for use in a human-operated keyboard.

The manufacturing cost of the diaphragm switch device is lower than that of a keyboard device made by wiring a cord. In such embodiments, the keyboard may be integrally incorporated within the body, usually in the form of a terminal or a small computer. This type of keyboard scans conductors in a switch matrix and does not require dedicated electronics because the signals are processed by a large number of components. Such a keyboard is also applicable to coded embodiments. Diaphragm switch devices reduce overall cost by eliminating electronic components that serve the same purpose as keyswitches as well as the regular printed circuit board that is an alternative form of keyboard. .

To maximize cost efficiency, the present invention provides a novel diaphragm switch device and method of manufacturing the same.

Hard printed circuits can be printed with etching-resistant material (engraved) in accordance with the desired pattern of the circuit by offset printing, photoprinting (8), or silk screen printing.
It is manufactured by applying a copper laminate to a circuit board laminated with copper. The prepared board is then placed in a chemical bath to remove any copper not protected by the resistive material. The present invention has been completed by applying this well-known technology in a specific manner according to the requirements of a diaphragm switch device used in a keyboard. Thus, a feature of the present invention resides in the combination of a simple circuit printing process with a highly reliable pad coating free of unwanted oxidation or moisture problems. The diaphragm switch device is constructed from a novel silk combination of flexible surfaces, hard metal conductor traces, and a protected, long-life switch pad. The manufactured keyboard meets or exceeds the temperature, humidity and contamination conditions of conventional open/close keyboard switches.

Referring to the drawings, one embodiment of a diaphragm switch device 10 designed to be incorporated into a "full travel" diaphragm key (9)-board is illustrated in detail. 1 Full travel'' refers to a mechanically movable keycap that is pressed down by a keyboard operator and is designed to be subjected to a resistive force while traveling through a normal operating distance. Such distances are those that users are accustomed to operating keyboards used on typewriter terminals, computer inputs, and related devices. The distance, or travel, of the semi-heated keycap is significantly greater than the desired distance of travel between the switch contacts.

FIG. 1 schematically illustrates the surroundings in which a diaphragm switch device 10 of the present invention is used. Diaphragm switch device 10 is supported by a rigid backing plate 16. The device 10 is positioned directly beneath a complementary panel 12 that mechanically supports a number of switch actuators, illustrated as key tops 11. The key top 11 can have a shape depending on the location where it is installed.

The layout or arrangement of the keyboard is not important in understanding the invention.

FIG. 2 is a detailed illustration of a single embodiment of a mechanical keyswitch actuator for use with diaphragm switch device 10. The device 10 includes a reciprocating plunger 15 fixed to the key top 11 and slidably guided within a support housing. The return spring 16 is
It consists of a compression spring and is mounted between the key top 11 and the housing 14. FIG. 2 shows the return spring 16
is shown in an extended or released state.

The actuator 17 with its spring removed projects from the underside of the plunger 15 in the direction of the diaphragm switch device 10 . The actuator 17 is guided in an extension extending downwardly from the pusher 15 and is adapted to engage the diaphragm switch device 10 on the opposite side of the rigid backing plate 13.

Actuator 17 selectively closes the internal switch (11) contacts within diaphragm switch device 10 when key top 11 is depressed. A spring support for the actuator 17 provides a compressible extension of the lower part 1111 of the plunger 15 so that the key top 11 has a predetermined nofle travel. The force applied to the actuator 17 is such that it can reliably close the switch contact located below it. The combined force exerted on the key tops 11 by the springs 16 and the spring-mounted actuators 17 must be selected to be such that each key top 11 can be operated by hand.

The key top 11, the panel 12, the diaphragm switch device 10, and the backing plate 1 are the components of the completed keyboard device. Preferably, they are connected by a plurality of struts and mounting screws 18 (see FIG. 2). The screws 18 extend upwardly through suitable spaced holes formed through the diaphragm switch device 10 and the backing plate 16.

4 and 5 illustrate a die-cut sheet consisting of the top layer 20, bottom layer 30, and spacer 40 of the diaphragm switch device (12) device 10. FIG. These elements are
Assembled as shown in FIG. 6, the
A number of diaphragm switches are provided which are actuated by the key top 11. Details of the switch are illustrated in FIGS. 7-9. Each switch is operated as shown in FIGS. 8 and 9.

Referring to FIG. 6, the top layer 20 is made from an electrically conductive flexible sheet material. Mylar “Mylar” (
Conventional polyester film, sold under the trade mark TM), is currently one of the preferred examples. The current film thickness is 0005 inches (0,00127α)
It is. Top layer 20 has a metallized inner surface, initially designated generally at 29. The metallization 19 has a thickness of 0.000 finch (0.00178 crn).
It is in the form of a 5 oz/in2 (2,20y-/crn2) electroplated copper foil. The coating 19 is
Preferably, it is laminated to a polyester film with a suitable thermosetting adhesive. Coating 19 must be oil-free for manufacturing purposes, as discussed below.

The inner surface 29 across the top layer 20 is provided with a number of conductive traces 21 . The traces 21 include trace sections 26 along pads 22 and connector connections 25 that project outwardly from the rectangular peripheral edges 24 of the top layer 20.
It extends between the terminals parallel to the

The traces 21 are comprised of hard metal conductors etched from a coating 19 of the base IJ ester film. They are covered by a coating of etching resistor (etching) 26 (7th
Figures to Figures 9). The etching resistance material 23 connects the layer of the conductive ink filter 6 on the pad 22 with the connector F! A2
5 and a similar layer of conductive ink 68 adjacent the outer edge of 5 . Conductive ink layer 6. The filter 8 preferably covers the coating of the etch-resistant material 2 filter, thereby ensuring the continuity of the metallization 19 (14).

The elements provided on the inner surface of the bottom layer 60 are composite (corresponding) to the elements described in connection with the top layer 2. A connector connecting portion 5 protruding outward from the peripheral edge 64
''-parallel trace sections 66 formed therein. A rectangular peripheral edge 64 serves as a boundary for the bottom layer 30.

Similar numbers are used for the various layers and coatings that define these elements.

Top layer 20 and bottom layer 60 are separated by a spacer 40 made of electrically insulating sheet material. Spacer 40, like top layer 20 and bottom layer 60, is preferably made from polyester film by gouging. Currently, this is 0.005 inches (0.005 inches).
, 0127z) and is coated on each side with an acrylic-based pressure sensitive adhesive. The produced film was initially handled and die-cut (15) with a pattern of openings as generally illustrated in FIG.
) A release liner (not shown) is attached to each side so that it can be removed.

The spacer 40 has a number of openings 41 formed therethrough according to a predetermined pattern corresponding to the desired switch placement on the diaphragm switch device 10. It is preferable that the openings 41 have the same size and each form a circular shape. The openings are connected by a connecting passage 42 for each group. For each group of a plurality of openings 41 and connecting passages 42,
Open ventilation holes 43 are formed through the bottom layer 60.

Spacer 40 is inserted between first layer 20 and bottom layer 60 with inner surfaces 29, 39 overlapping each other. Although the inner surfaces 29,39 are preferably laminated to the opposing flat surface of the spacer 400, the structural requirements of the diaphragm switch device 10 do not require that these tridents be laminated. If sealing the switch device is not a problem, these three elements can be partially attached. Top layer 20 (
16) By completely laminating the bottom layer 60 to the spacer 40, each switch area is effectively sealed. Thereafter, the diaphragm switch device should be completely top-sealed. As a result, the temperature of the conventional open/close switch,
Be able to meet or exceed humidity and contamination conditions. Ventilation holes 4 formed by communicating the bottom layer 60
6 faces downward and is located in a place where there is no risk of liquid entering the keyboard.
It does not reduce the product value.

For maximum protection of the output/input race sections 26.36 that extend across the connector joint 25.35, the inner surfaces of the top layer 20 and bottom layer 30 that cross the connector joint 25.35 are It is preferable to adhere to each other in the entire area. This has been found to reduce damage to the thin layer of copper. This copper thin layer is susceptible to damage when bent over a thick supporting polyester film. The laminate of two layers is
When table and compression occur within the outer polyester film element (17), it provides a balanced laminate structure. The neutral plane p-1' copper cladding located between the two applied film layers is effectively protected from tension and compression. This ensures that the Conerta pads will not be damaged even if they bend.

As illustrated in FIG. 1, a conventional terminal connector 27
The attached connector connecting portion 25. Clamp on filter 5,
That is, it is connectable, thereby allowing the diaphragm switch device 10 to be easily attached to associated electronic equipment.

In a laminate construction, the entire circumference of the top layer 20, bottom layer 60, and spacer 40 is sealed with an adhesive that sticks them together. Holes 28 for receiving the screws 18 are formed in position in the top layer 20 and the bottom layer O to avoid conductive elements. The laminating adhesive also effectively seals these mounting holes 28.

The process (18) for manufacturing the diaphragm switch device 10 begins with printing traces 21 in the desired pattern on the top layer 20 and the bottom layer 0. The printing process can be performed using any process. At present, the silk screen method is the most economical method for producing these trace patterns because it can easily produce the various trace patterns desired by the user.

Etch-resistant material 26 can be any printable masking material that does not erode when immersed in the underlying metallization etchant. For example, "MST+ 320 UV Curakl" sold by MST Chemical Co. of Rahway, New Chassis.
e Mask" can be used as a non-conductive etch-resistant material to practice the present invention. The etch-resistant material is curable by ultraviolet light and is compatible with conventional copper etchants, such as persulfate etchants. It can also be immersed in water.When silk screening is done properly,
Etch-resistant material is etched to a thickness of 0.000 inches (0.00178 mm) by passing it under a conventional ultraviolet lamp.
(19) crn).

Other suitable etching resistors can also be used in the printing process to form trace patterns. To trace? Since the traces are insulated from the switch device by inserting the spacer 40, the 85 etching resistive material can be made non-conductive as described above.
Or it could be made conductive. Suitable conductive etch-resistant materials include commercially available carbon, Φ, nickel, or chromium filled inks.

Next, a second printing process is performed on the top layer 20 and the bottom layer 0. This is accomplished by applying a conductive, etch-resistant ink to the metallized inner surface 29.39 to trace a complementary pattern of mating pads 22.32 and conductive pad areas 68 to trace 21.39. Formed at the end of filter 1.

In a preferred embodiment, the silver ink with a binder system based on polyester or acrylic resin is applied again by a silk screen printing process (20). The ink preferably contains a silver content of at least 60% by weight and the silver particle size should not exceed 2 microns. An example of an ink is "E S L-1112-8Ag lightning conductive ink" sold by Electro-Science Laboratories, Inc., Pennriquen, New Chassis.
There is. This ink is cured by drying at high temperatures. Typically, the preferred cure cycle is about 1 hour at 60°C.

Unless cost issues are considered, the above-mentioned silver-containing ink can be applied to traces 21, 31, pads 22, 32 and pad area 6.
8 can be used as an etching-resistant material. Alternatively, initially, traces 21, 31 . Pad 22
．． 32 and pad area 68 using a conductive, etch-resistant material, such as carbon-containing ink, and then printing pads 22 and pad area 88 with silver-containing ink.
Can you cover it?

Top layer 20 and bottom layer 60 may be finished to define the desired peripheral edges 24.34 and connector connections 25.35, either before or after the printing and etching process.

The metallized inner surfaces 29 of the top layer 20 and bottom layer 30, the printed area around the filter 9, are etched to remove any remaining patterned metallization that is not needed for the switch circuitry.

Removal of this material is accomplished by performing an etching process well known in the printed circuit board industry.

The diaphragm switch device should be placed face to face.
This is completed by inserting a flat surface opposite the spacer 400 onto the inner surface 29.390. Spacer 4
The opening 41 formed through the pad 2 that forms the pair
2. Place around position 32. Adhesion of the surfaces 29, 39 is accomplished by gluing the entire area of the spacer 40 or a limited area as described above.

The operation of each switch is illustrated in FIGS. 8 and 9. In the normal relaxed state of layers 20, 30, conductive coating 66 is open between (22) pairs of pads 22,32. When a given key top 11 is pressed down, the upper flexible top layer 20 closes the opening 41 of the spacer 40.
deflected through. Thereby, the pads 22.32 will be in surface contact and an electrical circuit closure will be formed between the corresponding traces 21.31 on the top layer 20 and the bottom layer O. Closure of the circuit can be detected by external electronics that can indicate a particular switch. These switches may be activated at any time.

Typically, both top layer 20 and bottom layer 30 are preferably made of flexible sheet material, but deflectability, ie, flexibility, is only essential for top layer 20. In some rod embodiments, the bottom layer 30 is rigid. This eliminates the need for a separate hard backing plate 62 as shown in FIGS. 1 and 2.

In such a case, the pasted connector connection part 25.35
becomes rigid in the final device.

(23)

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a keyboard including a diaphragm switch device. FIG. 2 is an enlarged plan view of the key switch assembled into the 1i switch device, and the right half is a sectional view. FIG. 3 is a plan view of the inside surface of the top layer of the device. FIG. 4 is a plan view of the spacer. FIG. 5 is a plan view of the bottom layer. FIG. 6 is an exploded perspective view of the diaphragm switch device. FIG. 7 is an enlarged plan view showing the switch device. FIG. 8 is a sectional view taken along line 8-8 in FIG. 7, showing the open state. FIG. 9 is a diagram similar to FIG. 8 showing the switch σ) in the closed state. DESCRIPTION OF SYMBOLS 10... Diaphragm switch device, 11... Key switch (24), 14... Housing, 17... Plunger, 20... Top layer, 60... Bottom layer, 4
o...Spacer. (25) How to write procedural amendments) April 1, 1948, Director-General Wakasugi Wakasugi's notice] Relationship with one person who made the ``Public Application No. 3 Pff'' in 1949 The date of the Key Fo-7 Fu Ko~o Reren Rijin Nei Ordinance: Showa 1997, month 1, day 1 (shipping date)

Claims (1)

Claims: (1) a top layer of an electrically insulating flexible sheet material having a metallized inner surface; an electrically insulating sheet material having a metallized inner surface; and a spacer made of an electrically insulating sheet material inserted between the m-layer and the bottom layer so that the cylinder inner surfaces face each other face-to-face; A diaphragm switch device for use in a keyboard comprising: a spacer having a number of openings formed through the spacer in a predetermined pattern corresponding to a desired switch arrangement; the inner surface has etched traces of metallization beginning at each spacer opening and terminating at a pair of overlapping conductive pads within each spacer opening;
(1) The paired pads are normally spaced apart from each other in a direction perpendicular to the two layers, with the top layer being deflected towards the bottom layer within a spacer opening surrounding them. the mating pads are movable into contact with each other when the metal coating is applied; A diaphragm switch device. (2) A diaphragm switch device according to claim 1, wherein inner surfaces of the top layer and the bottom layer are laminated to opposing flat surfaces of the spacer. (3) In the diaphragm switch device according to claim 1, the metal coating is copper; and the pair of pads is
(2) A diaphragm switch device comprising an optical surface area made of silver metallic ink coated directly on the copper coating. (4) In the diaphragm switch device according to claim 1, ``the two pairs of pads have overlapping surface areas made of silver metallic ink that extend beyond the periphery of the opening surrounding them. Tenaro diaphragm switch device. (5) The diaphragm switch device according to claim 1, wherein the paired pads have overlapping surface hook regions made of silver metallic ink that extend beyond the peripheral edges of their surrounding openings. a diaphragm switch device, wherein the remaining traces on the inner surfaces of the top layer and the bottom layer are coated with a resistor. (6) In the diaphragm switch device according to claim 1, the boundary edges of the top layer, the bottom layer, and the spacer extend in the same manner, and the outer peripheral edge of the switch device A diaphragm switch device that does not disturb its surroundings and thereby provides (3) a sealed configuration. (7) A diaphragm switch device according to claim 1, wherein the boundary edges of the top layer, the bottom layer and the spacer extend in the same manner, and a diaphragm switch device, wherein the top layer is continuous and conspicuously unobstructed; the top layer is continuous and conspicuously unobstructed; (8) In the diaphragm switch device according to claim 1, the boundary edges of the oil layer, the bottom layer and the spacer extend in the same manner, and the top layer is continuous and unobstructed; and the bottom layer communicates with the spacer opening; 4) A diaphragm switch comprising a ventilation hole formed in communication with the bottom layer. (9) In the diaphragm switch device according to claim 1, the top layer and the bottom layer have a connector connecting portion protruding therefrom so as to overlap each other: the top layer and the inner surfaces of the top and bottom layers are adapted to extend outwardly across their respective connector pads in parallel; and the inner surfaces of the top and bottom layers are adapted to extend outwardly across their respective connector pads in parallel; A diaphragm switch device that is directly bonded to each other throughout. 00 Printing a predetermined pattern of traces by applying an etch-resistant material onto the metallized surface of a top layer of electrically insulating flexible sheet material; a bottom layer of electrically insulating sheet material; printing traces of a complementary pattern by applying an etch-resistant material to the metallized surfaces of the layers; (5) etching into non-printed areas around the metallized surfaces of the top layer and the bottom layer; inserting opposing flat surfaces of a spacer of electrically insulating sheet material between the metallized surfaces of the top layer and the bottom layer in a face-to-face manner; A method of manufacturing a diaphragm switch device for use in a keyboard, whereby a number of apertures formed through the spacer are arranged around the locations of paired pads. 0υ In the method according to claim 10,
printing the trace by screening a coating of etch-resistant material onto the metallized surface before printing the pad by screening a coating of conductive ink onto the metallized surface; How to become. 021. The method of claim 11, wherein (6) the electrically conductive ink comprises a specific silver in a vapor binder. 1131. The method of claim 10, wherein the bottom layer is also flexible. ■) The method of claim 16, wherein the step of printing the traces is arranged along the protruding connector connections in complimentary positions of the top layer and the bottom layer. and bonding the metallized surfaces of the top layer and the bottom layer directly to each other around the connector interface. (I5) The method according to claim 10, further comprising a step of laminating opposing flat surfaces of the spacer on the surfaces of the metal coverings of the top layer and the bottom layer. Method. (7)