JP2020123481A - Pressure sensitive switch and manufacturing method thereof - Google Patents

Abstract

To provide a pressure sensitive switch improved in dust-proofness and waterproofness.SOLUTION: The present invention relates to a pressure sensitive switch comprising: a substrate 10; a first land 11 and a second land 12 which are disposed on the substrate; a dielectric member 14 which is disposed on the first land; a flexible conductive member 17 which is disposed at an upper side of the dielectric member separately from the dielectric member in such a manner that a clearance with the dielectric member becomes a predetermined distance and which shortens the distance to the dielectric member in response to being pressed from an upper side; a connection member 16 connecting the second land and the conductive member; an outer frame member 13 which is disposed on the substrate and in which an accommodation part 131 is formed; a sealing sheet 19 which is disposed on the outer frame member and seals the first land, the second land, the dielectric member and the conductive member that are accommodated in the accommodation part; a first electrode 102 connected to the first land; and a second electrode 104 connected to the second land.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pressure sensitive switch and a manufacturing method thereof.

A pressure sensitive switch is used as an operation switch used in mobile communication devices such as smartphones and electronic devices such as pen tablet devices. The pressure-sensitive switch has a dielectric member inside and a conductive member that is arranged adjacent to the dielectric portion with a gap in between, and when the switch is pressed from above, the static pressure changes due to the change in the distance between the dielectric member and the conductive member. It is a switch that detects a change in capacitance.

Since the electrostatic capacitance when the dielectric member and the conductive member are in contact with each other changes depending on the surface condition, the pressure sensitive switch is required to be dustproof and waterproof.

Patent Document 1 discloses a dielectric, a first electrode attached to one surface of the dielectric, a flexible second electrode disposed on the other surface side, a second electrode, and the like. A variable capacitance capacitor having a spacer that separates it from the surface of the variable capacitor is disclosed. The variable capacitor further has a pressing body that changes the distance between the second electrode and the other surface, and functions as a pressure sensitive switch.

JP 05-275283 A

However, the variable capacitor described in Patent Document 1 does not have dustproofness and waterproofness, and the electrostatic capacitance between the dielectric and the second electrode largely changes depending on the surface state of the contact surface, or It becomes undetectable.

An object of the present invention is to provide a pressure-sensitive switch that is easy to manufacture and has excellent dustproofness and waterproofness.

A pressure-sensitive switch according to the present invention includes a substrate, a conductive first land disposed on the substrate, a conductive second land disposed on the substrate so as to be insulated from the first land, and a second conductive land. The dielectric member is disposed above the dielectric member such that the distance between the dielectric member arranged on one land and the dielectric member when not pressed down from above is a predetermined distance. A flexible conductive member whose distance from the dielectric member becomes shorter than the isolation distance in response to being pressed from, a connection member for electrically connecting the second land and the conductive member, and An outer frame member that is disposed and has an accommodating portion that accommodates the first land, the second land, the dielectric member, and the conductive member, and the first land that is disposed on the outer frame member and is accommodated in the accommodating portion, the second land A sealing sheet for sealing the land, the dielectric member, and the conductive member; a first electrode electrically connected to the first land; and a second electrode electrically connected to the second land. Characterize.

In the pressure sensitive switch according to the present invention, it is preferable that the conductive member is a conductive spring that is convex upward.

The pressure-sensitive switch according to the present invention has a frame-like planar shape whose height is an isolation distance, and is disposed between the dielectric member and the conductive member, so that the dielectric member and the conductive member are separated by a separation distance. It is preferable to further include a spacer frame member that is separated.

The pressure-sensitive switch according to the present invention preferably further has an upper frame member between the outer frame member and the sealing sheet.

In the pressure-sensitive switch according to the present invention, the outer frame member is formed with a through hole penetrating the upper surface and the lower surface, and the connecting member is penetrated so that the upper end is in contact with the conductive member and the lower end is in contact with the second land. It is preferably inserted into the hole.

In the pressure-sensitive switch according to the present invention, it is preferable that the connecting member is attached along the inner side surface of the outer frame member.

In the pressure-sensitive switch according to the present invention, the connecting member houses the substrate, the first land, the second land, the dielectric member, the conductive member, the sealing sheet, and the outer frame member, and the conductive member extends along the outer surface of the outer frame member. It is preferable that the storage case is a flexible storage case.

The pressure-sensitive switch according to the present invention has a bottom portion having a downwardly convex shape, a rod-shaped shaft portion extending upward from the bottom portion, and a side surface of the shaft portion extending in a direction orthogonal to the extension direction of the shaft portion. A plunger having a flange and a bottom portion arranged to be in contact with the sealing sheet, an upper surface formed with an opening through which the shaft portion can penetrate, and a side surface extending in a direction orthogonal to the upper surface from an end portion of the upper surface. And a plunger case having, wherein the flange is preferably disposed between the upper surface and the sealing sheet.

A pressure-sensitive switch according to the present invention corresponds to a shape in which a plurality of boards are connected to a collective board in which a plurality of boards in which a first land and a second land insulated from the first land are arranged are connected. , A collective outer frame member having a shape in which a plurality of outer frame members constituting the pressure-sensitive switch are connected, a dielectric member is arranged on each first land, and each second land and a conductive member are electrically connected. A connecting member to be connected is arranged, a conductive member is arranged separately from each dielectric member, each conductive member is covered, a collective sealing sheet is arranged on the collective outer frame member, and a collective seal is arranged on the collective outer frame member. The collective substrate on which the stop sheet is arranged is heated to bond the collective substrate and the collective sealing sheet to the outer frame member, and also bond the second land, the electric member and the connecting member to each other on the collective outer frame member. It is characterized by including cutting the collective substrate in which the collective sealing sheet is arranged.

According to the present invention, it is possible to provide a pressure-sensitive switch which is easy to manufacture and has excellent dustproofness and waterproofness.

It is a figure explaining an outline of an example of composition of a pressure sensitive switch of a 1st embodiment, (a) is a perspective view of pressure sensitive switch 1, (b) is an exploded perspective view of pressure sensitive switch 1. , (C) are sectional views taken along the line AA' shown in (a). It is sectional drawing explaining the state which the pressure sensitive switch of 1st Embodiment changes by pushing down from above, (a) is sectional drawing when the pressure sensitive switch 1 is not pushed down from above, (b) 8A is a cross-sectional view when the pressure sensitive switch 1 is pressed from above. It is a figure which shows an example of the manufacturing method of a pressure sensitive switch. It is a figure explaining the outline of an example of composition of a pressure sensitive switch of a 2nd embodiment, (a) is a 3 perspective view of a pressure sensitive switch, (b) is an exploded perspective view of pressure sensitive switch 3, (C) is a sectional view taken along the line AA' shown in (a). It is sectional drawing explaining the state which changes when a pressure sensitive switch of 2nd Embodiment is pressed down from the upper part. (A) is a sectional view when the pressure-sensitive switch 3 is not pressed down from above, and (b) is a sectional view when the pressure-sensitive switch 3 is pressed down from above. It is a figure explaining the outline of an example of composition of a pressure sensitive switch of a 3rd embodiment, (a) is a perspective view of pressure sensitive switch 4, (b) is an exploded perspective view of pressure sensitive switch 4, (C) is a sectional view taken along the line AA' shown in (a). It is sectional drawing explaining the state which changes by the pressure sensitive switch of 3rd Embodiment pressing down from the upper part. (A) is a sectional view when the pressure-sensitive switch 4 is not pressed down from above, and (b) is a sectional view when the pressure-sensitive switch 4 is pressed down from above. It is a figure which shows the modification of the connection member of a pressure sensitive switch, (a) is sectional drawing which shows an example of the pressure sensitive switch 5 of the modification 1, (b) is an outer surface of the outer frame member of the modification 2. It is sectional drawing which shows an example which has an inner side surface which met. An example of the voltage detection system which detects the voltage between the 1st electrode and 2nd electrode of the pressure-sensitive switch of this invention corresponding to pressing from above is shown, (a) shows the pressure-sensitive capacitor equivalent to a pressure-sensitive switch. , (B) shows a block diagram of the voltage detection system.

Hereinafter, a pressure sensitive switch according to one aspect of the present disclosure will be described with reference to the drawings. However, it should be noted that the technical scope of the present disclosure is not limited to those embodiments, and extends to the inventions described in the claims and their equivalents. In the following description and drawings, components having the same functional configuration will be assigned the same reference numerals and overlapping description will be omitted.

[Outline of Configuration of Pressure Sensitive Switch of First Embodiment]
1A and 1B are diagrams for explaining the outline of the configuration of an example of the pressure-sensitive switch of the first embodiment, FIG. 1A is a perspective view of the pressure-sensitive switch, and FIG. 1B is an exploded perspective view of the pressure-sensitive switch. And (c) is a cross-sectional view taken along the line AA′ shown in (a).

The pressure sensitive switch 1 includes a substrate 10, a first land 11, a second land 12, an outer frame member 13, a dielectric member 14, a spacer frame member 15, a connecting member 16, a conductive member 17, an upper frame member 18, and a sealing sheet. Has 19. In the manufacturing process of the pressure-sensitive switch 1, each member is adhered using, for example, a thermosetting resin adhesive, so that the member constituting the pressure-sensitive switch 1 preferably has heat resistance that can cope with reflow.

The substrate 10 is a flat member made of, for example, an insulating resin material, and has a rectangular surface. The conductive first lands 11 are arranged on the substrate 10. The first land 11 is, for example, a rectangular flat plate conductor, is arranged in the central portion of the upper surface of the substrate 10, and the dielectric member 14 is mounted on the upper surface. A conductive second land 12 is arranged on the outer peripheral side of the first land 11 so as to be insulated from the first land 11. The second land 12 is, for example, a circular flat plate conductor. The second land 12 may be, for example, a rectangle instead of a circle, or may be a rectangular frame-shaped flat plate conductor surrounding the first land 11, and a plurality of flat plate conductors may be provided. The first land 11 and the second land 12 are formed of a conductive member such as a conductive plastic and are arranged on the surface of the substrate 10. The first land 11 and the second land 12 may be formed by etching a substrate on which a metal foil, for example, a copper foil is deposited.

The outer frame member 13 is arranged on the upper surface of the substrate 10 so as to surround the first land 11 and cover the second land 12. The outer frame member 13 is, for example, a rectangular frame-shaped member that is made of a resin material so as to match the outer circumference of the substrate 10, and is bonded to the upper surface of the substrate 10 via an adhesive agent or an adhesive member, for example, an adhesive sheet 20. It The adhesive or the adhesive member is preferably made of a thermosetting resin. This is because it is possible to heat and bond each member after the arrangement.

By placing the outer frame member 13 on the upper surface of the substrate 10, the outer frame member 13 surrounds the first land 11, and houses the second land 12, the dielectric member 14, the spacer frame member 15, and the conductive member 17. 131 is formed.

The outer frame member 13 has a through hole 132 and a notch guide 133. The through hole 132 is a hole for inserting the connecting member 16 for electrically connecting the second land and the conductive member 17, and is provided so as to be pulled out from the upper surface to the lower surface of the outer frame member 13. The through hole 132 is provided so that the lower surface side opening of the through hole 132 overlaps at least a part of the second land 12. The opening shape of the through hole 132 may be, for example, a rectangular shape other than a circle, as long as it corresponds to the shape of the connecting member.

Further, the adhesive sheet 20 for adhering the outer frame member 13 to the upper surface of the substrate 10 has a portion corresponding to the portion where the lower surface side opening of the through hole 132 and the second land 12 overlap. This is for electrically connecting the second land 12 and the conductive member 17. Similarly, when an adhesive, for example, a thermosetting resin adhesive is applied to dispose the outer frame member 13 on the upper surface of the substrate 10, it corresponds to a portion where the lower surface side opening of the through hole 132 and the second land 12 overlap. No adhesive is applied to the areas to be covered.

The notch guide 133 is a groove that fits into the protrusion 172 of the conductive member 17, and guides the protrusion 172 to the opening of the through hole 132 on the upper surface of the outer frame member 13.

The dielectric member 14 is a flat plate-shaped member, and is a dielectric material, for example, having a relative permittivity of 1,000 or more and a thickness of 0.2 mm or more, which is disposed on the first land 11. The dielectric is barium titanate, for example. The dielectric member 14 acts to increase the sensitivity of capacitance change due to a change in the distance of the gap between the dielectric member 14 and the conductive member 17 when the pressure sensitive switch is pressed from above. The dielectric member 14 is adhered to the upper surface of the first land 11 via an adhesive or an adhesive member (not shown).

The spacer frame member 15 is a flat plate-shaped frame member having an insulating property, and is arranged on the dielectric member 14 so that the height of the upper plane becomes a predetermined separation distance, and the dielectric member 14 and the conductive member 17 are separated from each other. To form a void. The spacer frame member 15 is, for example, an insulating resin having a thickness of 0.005 mm or more and 0.5 mm or less. The spacer frame member 15 is bonded to the upper surface of the dielectric member 14 via an adhesive agent or an adhesive member (not shown).

The connection member 16 is formed of, for example, a columnar conductive resin that is inserted into the through hole 132 and electrically connects the second land 12 and the conductive member 17. As an example, the connecting member 16 may have a cubic shape or a substantially conical shape. Alternatively, the connection member 16 may be formed by heat treatment after injecting a conductive thermosetting resin paste or a solder paste into the through hole 132 and disposing the conductive member 17. It is easy to ensure the electrical connection between the second land 12 and the conductive member 17.

The conductive member 17 has a main body portion 171 and a protruding portion 172, and is made of flexible conductive rubber, for example, in the form of a flat plate. The thickness of the conductive member 17 is 0.1 mm or more and 1.0 mm or less. The main body portion 171 is arranged on the spacer frame member 15, and the projecting portion 172 extends from the main body portion 171 toward the outer frame member 13 and fits with the notch guide 133 to form a through hole on the upper surface of the outer frame member 13. It reaches the 132 opening and is electrically connected to the connecting member 16.

The conductive member 17 is arranged above the dielectric member 14 such that the distance between the conductive member 17 and the dielectric member 14 when the pressure sensitive switch 1 is not pressed from above is a predetermined separation distance. When the conductive member 17 is pressed from above, the distance between the dielectric member 14 and the dielectric member 14 becomes shorter than a predetermined isolation distance, and the electrostatic capacitance between the dielectric member 14 and the conductive member 17 changes.

The upper frame member 18 is, for example, a rectangular frame-shaped member that is made of a resin material so as to match the outer periphery of the substrate 10, and is bonded to the upper surface of the outer frame member 13 via an adhesive or an adhesive member (not shown). It This is for strengthening the fixation of the protruding portion 172 that fits with the notch guide 133. The upper frame member 18 may be provided with a notch guide instead of the notch guide 133 of the outer frame member 13 or on the lower surface side. The upper frame member 18 may be omitted.

The encapsulating sheet 19 is bonded to the upper surface of the upper frame member 18 via an adhesive or an adhesive member (not shown) so as to cover the conductive member 17. The sealing sheet 19 is formed of, for example, a polyimide sheet having waterproofness and flexibility. By using the sealing sheet 19, the first land 11, the second land 12, the dielectric member 14, the spacer frame member 15, and the conductive member 17 accommodated in the accommodating portion 131 can be sealed, and the pressure sensitive The dustproofness and waterproofness of the switch 1 are ensured. Furthermore, it is preferable that the adhesive agent or the adhesive member for adhering each member has dustproof property and waterproof property.

FIG. 1C is a sectional view taken along the line AA′ shown in FIG. By disposing the outer frame member 13 on the upper surface of the substrate 10, the accommodating portion 131 that encloses the first land 11 and accommodates the second land 12, the dielectric member 14, the spacer frame member 15, and the conductive member 17 is formed.

A first electrode 102 connected to the first land 11 via the via hole 101 and a second electrode 104 connected to the second land 12 via the via hole 103 are formed on the lower surface of the substrate 10. The pressure sensitive switch 1 is connected to an external device via the first electrode 102 and the second electrode 104. A predetermined voltage is applied between the first electrode and the second electrode from an external device. The second electrode outputs a voltage between the second electrode and the first electrode, which changes according to the distance between the dielectric member 14 and the conductive member 17 becoming shorter than a predetermined separation distance.

FIG. 2 is a cross-sectional view illustrating a state in which the pressure-sensitive switch of the first embodiment changes when pressed down from above. (A) is a sectional view when the pressure sensitive switch 1 is not pressed down from above, and (b) is a sectional view when the pressure sensitive switch 1 is pressed down from above.

When the pressure sensitive switch 1 is not pressed down from above, the predetermined separation distance between the dielectric member 14 and the conductive member 17 is d. When the pressure sensitive switch 1 is pressed from above the sealing sheet 19 by the pressing body 200, for example, a finger or a pen made of a non-dielectric resin, the sealing sheet 19 becomes convex downward, and the main body 171 of the conductive member 17 is formed. Push down. The conductive member 17 is made of, for example, a flat plate-shaped conductive rubber having flexibility, so that the main body portion 171 is curved downwardly. Since the main body 171 is curved downward convexly, the distance between the dielectric member 14 and the conductive member 17 becomes d−Δd, which is shorter than a predetermined separation distance, and the electrostatic capacitance between the dielectric member 14 and the conductive member 17 is increased. Changes.

[Outline of an example of a method for manufacturing a pressure-sensitive switch]
Taking the pressure-sensitive switch of the first embodiment as an example, a process of collectively manufacturing a plurality of pressure-sensitive switches according to the present invention will be described.

FIG. 3 is a diagram showing an example of a method of manufacturing a pressure sensitive switch. (A) shows a collective outer frame member 23 having a shape in which a plurality of outer frame members are connected via a collective adhesive sheet 22 having a shape in which a plurality of adhesive sheets are connected on a collective substrate 21 in a shape in which a plurality of substrates are connected. It is a figure which shows the process performed. (B) is a figure which shows the process in which the dielectric member 14, the spacer frame member 15, the connection member 16, and the conductive member 17 are each arrange|positioned in each box 24 formed of the collective substrate 21 and the collective outer frame member 23. .. (C) is a figure which shows the process in which the collective upper frame member 25 of the shape with which the upper frame member was connected is arrange|positioned, and the collective sealing sheet 26 of the shape with which several sealing sheets were connected further is arrange|positioned. (D) is a figure which shows the process of cutting a collective substrate.

First, one aggregate substrate 21 having a shape in which a plurality of substrates 10 of the pressure-sensitive switch 1, for example, a total of 6 substrates 2×3, is prepared. On the upper surface of each substrate 10, first lands 11 and second lands 12 formed by pattern etching, for example, are arranged.

The collective adhesive sheet 22 is arranged on the upper surface of the collective substrate 21. The collective adhesive sheet 22 is an adhesive sheet in which the portions corresponding to the first land and the second land of each substrate 10 are open. The collective outer frame member 23 is arranged on the collective adhesive sheet 22. The collective outer frame member 23 is a collective outer frame member having a shape in which a plurality of outer frame members 13 are connected in the same arrangement as the arrangement of the substrates 10 of the collective substrate 21. By arranging the collective substrate 21 and the collective outer frame member 23, a plurality of, in this example, 2×3, six boxes 24 in total are formed. Each box 24 corresponds to a housing 131 that surrounds the first land 11 and houses the second land 12, the dielectric member 14, the spacer frame member 15, and the conductive member 17.

Next, in each box 24, the dielectric member 14, the spacer frame member 15, the connecting member 16, and the conductive member 17 are arranged. The dielectric member 14 is arranged on the first land 11, and the spacer frame member 15 is arranged on the dielectric member 14 via, for example, a thermosetting resin adhesive or an adhesive sheet. The connection member 16 is inserted into the through hole 132. When the connecting member 16 is, for example, a conductive thermosetting resin paste or a solder paste, the paste is injected into the through hole 132 using a dispenser. The conductive member 17 is arranged so as to fit into the notch guide 133.

Further, a collective upper frame member 25 having a shape in which upper frame members are connected to each other is arranged, and a collective sealing sheet 26 having a shape in which a plurality of sealing sheets are further connected is provided, for example, with a thermosetting resin adhesive or an adhesive sheet. A collective pressure-sensitive switch 27, which is arranged and connected to the pressure-sensitive switch 1, is formed. When the pressure-sensitive switch 1 does not use the upper frame member, the collective upper frame member 25 is not arranged. The collective pressure-sensitive switch 27 is subjected to a heat treatment for thermosetting the adhesive or the adhesive sheet and melting the conductive thermosetting resin paste and solder paste used for the connecting member 16. After the heat treatment, after the collective pressure-sensitive switch 27 reaches room temperature, the collective pressure-sensitive switch 27 is cut as shown by the broken line in FIG. 3D, and in this example, a total of 6 sensors of 2×3 are detected. It becomes the pressure switch 1.

[Outline of Configuration of Pressure Sensitive Switch of Second Embodiment]
In the pressure-sensitive switch of the first embodiment, pressing from above is performed on the sealing sheet. In the pressure-sensitive switch of the second embodiment, the plunger is provided on the sealing sheet, and the pressing from above is performed on the plunger.

4A and 4B are views for explaining the outline of the configuration of an example of the pressure-sensitive switch of the second embodiment, FIG. 4A is a perspective view of the pressure-sensitive switch, and FIG. 4B is an exploded perspective view of the pressure-sensitive switch. And (c) is a cross-sectional view taken along the line AA′ shown in (a).

The pressure sensitive switch 3 includes a substrate 10, a first land 11, a second land 12, an outer frame member 13, a dielectric member 14, a spacer frame member 15, a connecting member 16, a conductive member 17, an upper frame member 18, and a sealing sheet 19. , A plunger 31 and a plunger case 32.

The substrate 10, the first land 11, the second land 12, the outer frame member 13, the dielectric member 14, the spacer frame member 15, the connection member 16, the conductive member 17, the upper frame member 18, and the encapsulating sheet 19 are the embodiments. Since it is the same as the pressure sensitive switch 1 of No. 1, description thereof will be omitted.

The plunger 31 is arranged on the sealing sheet 19. The plunger 31 includes a bottom portion 311 having a convex shape that is in contact with the sealing sheet 19, a rod-shaped shaft portion 312 that extends upward from the bottom portion 311, and a side surface of the shaft portion 312 that is orthogonal to the extension direction of the shaft portion 312. And a flange 313 extending in the direction. The plunger 31 is formed of, for example, a resin mold made of polyphthalamide.

The plunger case 32 is, for example, a rectangular frame-shaped case that is made of a resin material so as to match the outer circumference of the substrate 10, and is adhered to the upper surface of the sealing sheet 19 via an adhesive or an adhesive member (not shown). It The plunger case 32 has an upper surface on which an opening 321 is formed and a side surface extending in a direction orthogonal to the upper surface from an end portion of the upper surface, and a portion of the plunger 31 above the flange 313 is projected from the opening 321. The lower part of the plunger 31 including the flange 313 is stored.

When pressure is applied from above, the plunger 31 moves in a direction perpendicular to the substrate 10 and the pressure is transmitted to the sealing sheet 19. Through the plunger 31, it is possible to detect a subtle pressure change.

FIG. 5 is a cross-sectional view illustrating a state in which the pressure-sensitive switch of the second embodiment changes when pressed from above. (A) is a sectional view when the pressure-sensitive switch 3 is not pressed down from above, and (b) is a sectional view when the pressure-sensitive switch 3 is pressed down from above.

When the pressure sensitive switch 3 is not pressed from above, the predetermined separation distance between the dielectric member 14 and the conductive member 17 is d. In the pressure-sensitive switch 3, when the head of the plunger 31 is pushed by the pushing body 200, the sealing sheet 19 in contact with the bottom portion 311 of the plunger 31 is pushed down from above, so that the sealing sheet 19 moves downward. It becomes convex and pushes down the main body 171 of the conductive member 17. The conductive member 17 is made of, for example, a flat plate-shaped conductive rubber having flexibility, so that the main body portion 171 is curved downwardly. Since the main body 171 is convexly curved downward, the distance between the dielectric member 14 and the conductive member becomes d-Δd, which is shorter than the predetermined separation distance, and the electrostatic capacitance between the dielectric member 14 and the conductive member 17 is reduced. Change.

[Outline of Configuration of Pressure Sensitive Switch of Third Embodiment]
The pressure sensitive switches of the first and second embodiments use a flat plate-shaped conductive member. The pressure sensitive switch of the second embodiment uses a conductive spring having a convex upward as a conductive member.

6A and 6B are views for explaining the outline of the configuration of an example of the pressure-sensitive switch of the third embodiment, FIG. 6A is a perspective view of the pressure-sensitive switch, and FIG. 6B is an exploded perspective view of the pressure-sensitive switch. And (c) is a cross-sectional view taken along the line AA′ shown in (a).

The pressure sensitive switch 4 includes a substrate 40, a first land 41, a second land 42, an outer frame member 43, a dielectric member 44, a connecting member 45, a conductive member 46, and a sealing sheet 47.

The substrate 40 is a flat member made of, for example, an insulating resin material, and has a rectangular surface. The conductive first land 41 is disposed on the substrate 40. The first land 41 is, for example, a rectangular flat plate conductor, is arranged at the center of the upper surface of the substrate 40, and the dielectric member 44 is mounted on the upper surface. A conductive second land 42 is arranged on the outer peripheral side of the first land 41 so as to be insulated from the first land 41. The second land 42 is, for example, a circular flat plate conductor. The second land 42 may be, for example, a rectangular frame-shaped flat plate conductor that surrounds the first land 41. The first land 41 and the second land 42 are formed of a conductive material such as conductive plastic, and are arranged on the surface of the substrate 40. The first land 41 and the second land 42 may be formed by etching a substrate on which a metal foil, for example, a copper foil is deposited.

The outer frame member 43 is arranged on the upper surface of the substrate 40 so as to surround the first land 41 and cover the second land 42. The outer frame member 43 is, for example, a rectangular frame-shaped member that is made of a resin material so as to match the outer circumference of the substrate 40, and is bonded to the upper surface of the substrate 40 via an adhesive agent or an adhesive member, such as the adhesive sheet 20. It

By arranging the outer frame member 43 on the upper surface of the substrate 40, the outer frame member 43 surrounds the first land 41 and forms a housing portion 431 that houses the second land 42, the dielectric member 44, and the conductive member 46. ..

The outer frame member 43 has a through hole 432 and two facing notch portions 433 and 434 that are formed by notching the inner surface of the outer frame member. The through hole 432 is a hole for inserting the connecting member 45 for electrically connecting the second land 42 and the conductive member 46, and is so formed as to be removed from the upper surface of the cutout portion 433 to the lower surface of the outer frame member 43. It is provided in. The through hole 432 is provided such that the lower surface side opening of the through hole 432 overlaps at least a part of the second land 42. The opening shape of the through hole 432 may be, for example, a rectangular shape other than a circle. This is because it corresponds to the shape of the connecting member 45.

Further, the adhesive sheet 48 for adhering the outer frame member 43 to the upper surface of the substrate 40 has an opening corresponding to a portion where the lower surface side opening of the through hole 432 and the second land overlap. This is for electrically connecting the second land and the conductive member 46. Similarly, when an adhesive, for example, a thermosetting adhesive is applied to bond the outer frame member 43 to the upper surface of the substrate 40, a portion corresponding to a portion where the lower surface side opening of the through hole 432 and the second land 42 overlap. No adhesive is applied to the.

The two notches 433 and 434 are provided so as to face each other by notching the inner surface of the outer frame member 43 in order to dispose the two ends of the conductive member 46 that is bridged over the dielectric member 44. ..

The dielectric member 44 is a flat plate-shaped member, and is a dielectric material that is disposed on the first land 41 and has, for example, a relative dielectric constant of 1,000 or more and a thickness of 0.2 mm or more. The dielectric member 44 acts to increase the sensitivity of the capacitance change due to the change in the distance of the gap between the dielectric member 44 and the conductive member 46 when the pressure sensitive switch 4 is pressed from above. The dielectric member 44 is adhered to the upper surface of the first land 41 via an adhesive or an adhesive member (not shown).

The connection member 45 is formed of, for example, a columnar conductive resin that is inserted into the through hole 432 and electrically connects the second land 42 and the conductive member 46. As an example, the connecting member 45 may have a cubic shape. Alternatively, the connection member 45 may be formed by heating after injecting a conductive thermosetting resin paste or a solder paste into the through hole 432 and disposing the conductive member 46.

The conductive member 46 is a conductive plate spring member having elasticity that can bend when pressed from above, and is made of, for example, stainless steel. Further, the conductive member 46 may be a spring member made of a conductive resin material. The conductive member 46 has a main body 461 having a curved spring shape, and a protrusion 462 that is bent and extends from the end of the main body 461 toward the inside of the main body. The conductive member 46 is arranged in the two notches 433 and 434 so as to be convex upward with respect to the dielectric member 44.

The conductive member 46 is bridged over the dielectric member 44 and is dielectrically arranged above the dielectric member 44 so that the distance between the conductive member 46 and the dielectric member 44 is a predetermined distance when the pressure sensitive switch 4 is not pressed from above. It is spaced apart from the member 44 and forms an air gap isolated from the dielectric member 44. When the pressure-sensitive switch 4 is pressed from above, the capacitance between the first land 41 and the main body 461 of the conductive member 46 changes due to the change in the separation distance between the dielectric member 44 and the main body 461 of the conductive member 46.

The projecting portion 462 is bent from the end portion of the main body portion 461 and extends inward of the main body portion and extends to reach the opening of the through hole 432 on the upper surface of the cutout portion 433, and thus is electrically connected to the connecting member 45. ..

The encapsulating sheet 47 is bonded to the upper surface of the outer frame member 43 via an adhesive or an adhesive member (not shown) so as to cover the conductive member 46. The sealing sheet 47 is formed of, for example, a polyimide sheet having waterproofness and flexibility. By using the sealing sheet 47, the first land 41, the second land 42, the dielectric member 44, and the conductive member 46 housed in the housing portion 431 can be sealed, and the dustproof property of the pressure-sensitive switch 4 can be achieved. , Waterproof property is secured. Furthermore, it is preferable that the adhesive agent or the adhesive member for adhering each member has dustproof property and waterproof property.

FIG. 6C is a sectional view taken along the line AA′ shown in FIG. By disposing the outer frame member 43 on the upper surface of the substrate 40, the accommodating portion 431 that encloses the first land 41 and accommodates the second land 42, the dielectric member 44, and the conductive member 46 is formed.

A first electrode 402 connected to the first land 41 via the via hole 401 and a second electrode 404 connected to the second land 42 via the via hole 403 are formed on the lower surface of the substrate 40. The pressure sensitive switch 4 is connected to an external device via the first electrode 402 and the second electrode 404.

FIG. 7 is a cross-sectional view illustrating a state in which the pressure-sensitive switch of the third embodiment changes when pressed down from above. (A) is a cross-sectional view when the pressure-sensitive switch is not pressed down from above, and (b) is a cross-sectional view when the pressure-sensitive switch is pressed down from above.

When the pressure sensitive switch 4 is not pressed from above, the predetermined separation distance between the dielectric member 44 and the conductive member 46 is d. When the sealing sheet 47 is pressed down from above by the pressing body 200, the sealing sheet 47 becomes convex downward and pushes down the main body portion 461 of the conductive member 46. Since the conductive member 46 is a conductive leaf spring member having a bendable elasticity, the main body portion 461 is bent downward, and the side surfaces of the two cutout portions 433, 434 of the outer frame member 43 facing each other. It spreads in the direction and contacts the respective side surfaces of the cutout portions 433 and 434. Due to the bending of the main body portion 461, the distance between the dielectric member 44 and the conductive member 46 becomes d-Δd shorter than a predetermined separation distance, and the capacitance between the dielectric member 14 and the conductive member 17 changes.

[Modification of connection member]
In the pressure sensitive switches of the first to third embodiments, the connecting member is inserted into the through hole of the outer frame member. The pressure sensitive switch of the first modification is an example in which the connecting member is arranged along the inner side surface of the outer frame member. The pressure sensitive switch of the second modification is an example in which the connecting member is a conductive storage case and is arranged along the outer surface of the outer frame member. Although a modified example of the pressure sensitive switch 1 of the first embodiment will be described for simplification of description, the modified example of the connection member is not limited to the pressure sensitive switch of the first embodiment.

8A and 8B are views showing a modified example of the connection member of the pressure sensitive switch, FIG. 8A is a sectional view showing an example of the pressure sensitive switch of the modified example 1, and FIG. 8B is a pressure sensitive switch of the modified example 2. It is sectional drawing which shows an example.

The pressure sensitive switch 5 of the first modification includes a substrate 10, a first land 11, a second land 52, an outer frame member 53, a dielectric member 14, a spacer frame member 15, a connecting member 56, a conductive member 57, an upper frame member 18, And a sealing sheet 19. The connection member 56 is attached along the inner side surface of the outer frame member 53. Therefore, the second land 52 on the substrate 10 moves toward the first land 11 so as to connect to the connecting member 56. The via hole 503 and the second electrode 504 move so as to correspond to the movement of the second land 52. The protruding portion 572 of the conductive member 57 is short so as to connect to the connecting member 56. Further, the outer frame member 53 is not provided with a through hole and a notch guide.

The pressure sensitive switch 6 of Modification 2 includes a substrate 10, a first land 11, a second land 62, an outer frame member 63, a dielectric member 14, a spacer frame member 15, a conductive member 67, an upper frame member 18, and a sealing sheet. It has a conductive storage case 66 for storing 19. The storage case 66 is, for example, a case made of metal or conductive resin. The storage case 66 covers the sealing sheet 19 and reaches the lower surface of the substrate 10 along the outer side surfaces of the outer frame member 63 and the upper frame member 18. The second land 62 extends to the outer periphery of the substrate 10 so as to be electrically connected to the storage case 66, and the protrusion 672 extends to the outer surface of the outer frame member 63 so as to be electrically connected to the storage case 66. doing. The conductive storage case 66 functions as a connecting member.

By fixing the storage case 66 and the sealing sheet between the storage case 66 and the outer periphery of the substrate 10 with a waterproof adhesive, the dustproof property and the waterproof property of the pressure sensitive switch 6 are further enhanced. If the conductor pattern extends from the second electrode 604 to the storage case 66 and is electrically connected, the second land 62 becomes unnecessary.

[Voltage-sensitive switch voltage detection system]
An example of the voltage detection system for detecting the voltage between the first electrode and the second electrode of the pressure-sensitive switch of the present invention which corresponds to the pressing from above will be described. For simplicity of explanation, the pressure-sensitive switch 1 of the first embodiment will be described as an example, but the voltage detection system is not limited to the pressure-sensitive switch 1 of the first embodiment.

FIG. 9 shows an example of a voltage detection system for detecting the voltage between the first electrode and the second electrode of the pressure-sensitive switch of the present invention, which corresponds to pressing from above, and FIG. FIG. 3B shows a piezoelectric capacitor, and FIG. 7B shows a block diagram of the voltage detection system.

The pressure-sensitive switch 1 is equivalent to the variable capacitor 7 because the electrostatic capacitance changes in response to the change in the isolation distance between the dielectric member 14 and the conductive member 17 in response to being pressed from above. The first electrode 102 and the second electrode 104 correspond to the terminals of the variable capacitor 7, respectively. The electrostatic capacitance of the variable capacitor 7 is represented by Cs.

The voltage detection system 8 includes an oscillation circuit 81, a switched capacitor circuit 82 connected to the output terminal of the oscillation circuit 81, a sample hold circuit 83 connected to the output terminal of the switched capacitor circuit 82, and an output terminal of the oscillation circuit 81. It has a monostable multivibrator 84 connected between it and the sample hold circuit 83, and an amplifier 85 connected to the output terminal of the sample hold circuit 83.

The switched capacitor circuit 82 includes an operational amplifier 86, a reference capacitor 87 having an electrostatic capacitance of Cr connected between the inverting input terminal of the operational amplifier 86 and the oscillation circuit 81, and an inverting input terminal of the operational amplifier 86 and an output terminal. It has a variable capacitor 7 having a capacitance of Cs connected thereto, and an analog switch 88 connected in parallel to the variable capacitor 7 and connected to the oscillation circuit 81.

When the analog switch 88 is switched in synchronization with the oscillation circuit 81, a half-wave amplitude-modulated output proportional to the quotient of the capacitances of the variable capacitor 7 and the reference capacitor 87 is obtained. This output voltage Vout is
Vout=-Vp.(Cr/Cs)
Is represented. Here, Vp is a voltage applied to the variable capacitor 7 and the reference capacitor 87.

The monostable multivibrator 84 that receives the output signal of the oscillation circuit 81 generates a timing pulse and supplies it to the sample hold circuit 83. The sample hold circuit 83 holds the output of the operational amplifier 86 at the time of receiving the timing pulse and gives it to the amplifier 85. The voltage detection system 8 makes it possible to detect the output voltage Vout proportional to the electrostatic capacitance Cr of the variable capacitor 7.

In the pressure-sensitive switch according to the present invention, the planar shape of the substrate has been described as a rectangular shape, but other planar shapes such as a circular shape may be used. In addition, at least one of the first land, the outer frame member, the dielectric member, the spacer frame member, the main body portion of the conductive member, the upper frame member, and the sealing sheet, which are arranged according to the substrate shape, has a circular planar shape. It may be.

It will be appreciated by those skilled in the art that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the invention.

1, 3, 4, 5, 6 Pressure-sensitive switch 10, 40 Substrate 102, 402 First electrode 104, 404, 504, 604 Second electrode 11, 41 First land 12, 42, 52, 62 Second land 13, 43, 53, 63 Outer frame member 14, 44 Dielectric member 15 Spacer frame member 16, 45, 56, 66 Connecting member 17, 46 Conductive member 18 Upper frame member 19, 47 Encapsulating sheet 21 Assembly board 22 Assembly adhesive sheet 23 Assembly Outer frame member 24 Box 25 Assembly upper frame member 26 Assembly sealing sheet 27 Assembly pressure sensitive switch 8 Voltage detection system

Claims (9)

Board,
A conductive first land disposed on the substrate;
A conductive second land disposed on the substrate so as to be insulated from the first land;
A dielectric member disposed on the first land,
The dielectric member is arranged above the dielectric member such that the distance between the dielectric member and the dielectric member when not pressed down from above is a predetermined separation distance. A flexible conductive member having a distance from the dielectric member shorter than the isolation distance;
A connection member for electrically connecting the second land and the conductive member;
An outer frame member that is disposed on the substrate and has a housing portion that houses the first land, the second land, the dielectric member, and the conductive member;
A sealing sheet that is disposed on the outer frame member and that seals the first land, the second land, the dielectric member, and the conductive member housed in the housing portion,
A first electrode electrically connected to the first land;
A second electrode electrically connected to the second land;
Pressure sensitive switch. The pressure-sensitive switch according to claim 1, wherein the conductive member is a conductive spring that is convex upward. A spacer that has a frame-like planar shape whose height is the separation distance, and is arranged between the dielectric member and the conductive member to separate the dielectric member and the conductive member by the separation distance. The pressure-sensitive switch according to claim 1, further comprising a frame member. The pressure sensitive switch according to claim 1, further comprising an upper frame member between the outer frame member and the sealing sheet. The outer frame member has a through hole penetrating the upper surface and the lower surface,
The pressure sensitive switch according to claim 1, wherein the connection member is inserted into the through hole such that an upper end thereof contacts the conductive member and a lower end thereof contacts the second land. The pressure sensitive switch according to claim 1, wherein the connecting member is attached along an inner side surface of the outer frame member. The connection member accommodates the substrate, the first land, the second land, the dielectric member, the conductive member, the sealing sheet, and the outer frame member, and has conductivity along the outer surface of the outer frame member. The pressure-sensitive switch according to any one of claims 1 to 4, which is a flexible storage case. A bottom portion having a downwardly convex shape, a rod-shaped shaft portion extending upward from the bottom portion, and a flange extending in a direction orthogonal to the extension direction of the shaft portion from a side surface of the shaft portion, A plunger arranged so that the bottom portion is in contact with the sealing sheet,
Further comprising an upper surface having an opening through which the shaft portion can penetrate, and a plunger case having a side surface extending in a direction orthogonal to the upper surface from an end portion of the upper surface,
The flange is arranged between the upper surface and the sealing sheet,
The pressure sensitive switch according to any one of claims 1 to 5. The pressure-sensitive switch is configured corresponding to a shape in which a plurality of substrates are connected to a collective substrate having a shape in which a plurality of substrates on which first lands and second lands insulated from the first lands are arranged are connected. Place a collective outer frame member having a shape in which a plurality of outer frame members are connected,
A dielectric member is arranged on each of the first lands,
A connecting member for electrically connecting each of the second lands and the conductive member is arranged,
Arranging the conductive members separately from the dielectric members,
Covering each of the conductive members, placing a collective sealing sheet on the collective outer frame member,
The collective substrate on which the collective encapsulating sheet is arranged is heated on the collective outer frame member to bond the collective substrate and the collective encapsulating sheet to the collective outer frame member, and the second land and the Bonding the electric member and the connecting member,
Cutting the collective substrate in which the collective sealing sheet is arranged on the collective outer frame member,
A method for manufacturing a pressure-sensitive switch including the above.

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