WO2023176902A1

WO2023176902A1 - Pressure sensor

Info

Publication number: WO2023176902A1
Application number: PCT/JP2023/010169
Authority: WO
Inventors: 雄樹西川; 純二宮下
Original assignee: シチズン電子株式会社; シチズン時計株式会社
Priority date: 2022-03-15
Filing date: 2023-03-15
Publication date: 2023-09-21

Abstract

A pressure sensor 1 comprises: a substrate; a conductive first land arranged on the substrate; a conductive second land arranged on the substrate so as to be insulated from the first land; a dielectric member arranged on the first land; a spacer arranged on the dielectric member; a flexible conductive member arranged on the spacer and connected to the second land; an outer frame member arranged on the substrate and forming, together with the substrate, an accommodation section accommodating the first land, the second land, the dielectric member, the spacer, and the conductive member; a sealing sheet fixed on the outer frame member and sealing the accommodation section; a first electrode electrically connected to the first land; and a second electrode electrically connected to the second land. The length from one end of the sealing sheet to the other end thereof is longer than the length from one end of the outer frame member to which the one end of the sealing sheet is fixed, to the other end of the outer frame member to which the other end of the sealing sheet is fixed.

Description

pressure sensor

The present disclosure relates to a pressure-sensitive sensor.

Pressure-sensitive sensors that are installed as operation switches in mobile communication devices such as smartphones and electronic devices such as pen tablet devices are known. For example, Japanese Patent Laid-Open No. 2020-123481 discloses a pressure-sensitive method for sealing a housing part that accommodates a dielectric member and a flexible conductive member disposed adjacent to the dielectric member with a sealing sheet through a spacer. A sensor is described, and by sealing the storage part that accommodates the dielectric member and the conductive member with a sealing sheet, the dustproof and waterproof properties of the dielectric member and the conductive member are improved, and the contamination of the dielectric member and the conductive member is prevented. This can prevent the detection accuracy from decreasing.

However, in the pressure-sensitive sensor described in JP-A No. 2020-123481, the sealing sheet is formed of a resin with low flexibility such as polyimide resin, so when the pressure-sensitive sensor is pressed down, the conductive member is pressed down through the sealing sheet. Part of the force may be absorbed by the sealing sheet, reducing detection sensitivity.

An object of the present disclosure is to provide a pressure-sensitive sensor that has excellent dustproof and waterproof properties and high detection sensitivity.

A pressure-sensitive sensor according to the present disclosure includes a substrate, a first conductive land disposed on the substrate, a second conductive land disposed on the substrate so as to be insulated from the first land, and a second conductive land disposed on the substrate so as to be insulated from the first land. a dielectric member disposed on the land, a spacer disposed on the dielectric member, a flexible conductive member disposed on the spacer and connected to the second land, and a flexible conductive member disposed on the substrate and connected to the first land. , an outer frame member that forms, together with the substrate, an accommodating portion that accommodates the second land, the dielectric member, the spacer, and the conductive member; a sealing sheet that is fixed on the outer frame member and seals the accommodating portion; It has a first electrode electrically connected to the second land and a second electrode electrically connected to the second land, and the length from one end of the sealing sheet to the other end is such that one end of the sealing sheet is fixed. The length between one end of the fixed outer frame member and the other end of the sealing sheet is longer than the length between the other end of the fixed outer frame member.

In the pressure-sensitive sensor according to the present disclosure, the sealing sheet includes an outer circumferential portion fixed on the outer frame member, a central portion surrounded by the outer circumferential portion and arranged farther from the conductive member than the outer circumferential portion, and an outer circumferential portion. It is preferable to have a connecting portion extending from the inner edge of the portion toward the outer edge of the center portion and connecting the outer peripheral portion and the center portion.

In the pressure-sensitive sensor according to the present disclosure, the thickness of the connecting portion is preferably thinner than the thickness of the central portion and the outer peripheral portion.

Further, the pressure-sensitive sensor according to the present disclosure includes a substrate, a conductive first land disposed on the substrate, and 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; a spacer disposed on the dielectric member; a flexible conductive member disposed on the spacer and connected to the second land; an outer frame member that forms, together with the substrate, an accommodating portion that accommodates the first land, the second land, the dielectric member, the spacer, and the conductive member; a sealing sheet that is fixed on the outer frame member and seals the accommodating portion; It has a first electrode electrically connected to the land and a second electrode electrically connected to the second land, and an opening through which air can flow in and out is formed in a region surrounded by the spacer. .

In the pressure-sensitive sensor according to the present disclosure, the spacer preferably has a frame-like shape with a portion missing, and the opening is preferably the missing portion of the spacer.

In the pressure-sensitive sensor according to the present disclosure, the spacer has a frame-like shape in which a recess is formed on either the surface facing the dielectric member or the surface facing the conductive member, and the opening is a recess. is preferred.

In the pressure-sensitive sensor according to the present disclosure, the spacer includes a first spacer that is arranged between the dielectric member and the conductive member and has a frame-like shape, and a second spacer that is arranged so as to overlap the first spacer. It is preferable to have.

In the pressure-sensitive sensor according to the present disclosure, the second spacer is arranged between the dielectric member and the first spacer, the first spacer is a soft layer, and the second spacer is made of a material whose hardness is higher than that of the soft layer. It is preferable to have a hard layer formed of.

In the pressure-sensitive sensor according to the present disclosure, it is preferable that the second spacer is disposed between the dielectric member and the first spacer, and that the inner edge of the second spacer protrudes more inward than the inner edge of the first spacer.

In the pressure-sensitive sensor according to the present disclosure, it is preferable that the second spacer has a frame-like shape with a portion missing.

In the pressure-sensitive sensor according to the present disclosure, both the first spacer and the second spacer have a frame-like shape with a part missing, and the first spacer and the second spacer It is preferable that the missing parts are arranged so that they do not overlap each other when viewed in plan.

In the pressure-sensitive sensor according to the present disclosure, both the first spacer and the second spacer have a frame-like shape with a part missing, and the first spacer and the second spacer It is preferable that the missing portions are arranged so that they partially overlap when viewed in plan.

According to the present disclosure, the pressure-sensitive sensor can have excellent dustproof and waterproof properties and high detection sensitivity.

1 is a diagram showing a pressure-sensitive sensor according to a first embodiment, (a) is a perspective view of the pressure-sensitive sensor, (b) is an exploded perspective view of the pressure-sensitive sensor, and (c) is a perspective view of the pressure-sensitive sensor shown in (a). FIG. 3 is a sectional view taken along line AA'. 2A and 2B are cross-sectional views illustrating a pressed state of the pressure-sensitive sensor shown in FIG. 1, in which (a) is a cross-sectional view of the pressure-sensitive sensor 1 before being pressed, and (b) is a cross-sectional view of the pressure-sensitive sensor 1 while being pressed. 2 is a diagram showing the method for manufacturing the pressure-sensitive sensor shown in FIG. 1, in which (a) shows the first step, (b) shows the second step, (c) shows the third step, and (d) shows the third step. The fourth step is shown. (a) is a cross-sectional view of a pressure-sensitive sensor according to a first modification, and (b) is a cross-sectional view of a pressure-sensitive sensor according to a second modification. FIG. 7 is an exploded perspective view of a pressure-sensitive sensor according to a second embodiment. FIG. 7 is an exploded perspective view of a pressure-sensitive sensor according to a third modification. It is an exploded perspective view of the pressure sensitive sensor concerning the 4th modification. FIG. 3 is a cross-sectional view of a pressure-sensitive sensor according to a third embodiment. (a) is a cross-sectional view showing a pressed state of the pressure-sensitive sensor according to the first embodiment, and (b) is a cross-sectional view showing the pressed-down state of the pressure-sensitive sensor according to the third embodiment.

Hereinafter, a pressure-sensitive sensor 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 these embodiments, but extends to the inventions described in the claims and their equivalents.

(Configuration and function of pressure-sensitive sensor of first embodiment)
1 is a diagram showing a pressure-sensitive sensor according to a first embodiment, FIG. 1(a) is a perspective view of the pressure-sensitive sensor, FIG. 1(b) is an exploded perspective view of the pressure-sensitive sensor, and FIG. (c) is a sectional view taken along line AA' shown in FIG. 1(a).

The pressure sensor 1 includes a substrate 10, a first land 11, a second land 12, a lower frame member 13, a dielectric member 14, a spacer 15, a connecting member 16, a conductive member 17, and an upper frame member. 18 and a sealing sheet 19. Since the pressure sensor 1 adheres the substrate 10 to the sealing sheet 19 by heating by reflow, each of the substrate 10 to the sealing sheet 19 has heat resistance that can withstand the heating by reflow. In the pressure-sensitive sensor 1, the length from one end of the sealing sheet 19 to the other end is the length between the lower frame member 13 and the upper frame member 18 to which one end of the sealing sheet 19 is fixed, and the length of the sealing sheet 19 from one end to the other end of the sealing sheet 19. The length is longer than the length to the other ends of the lower frame member 13 and the upper frame member 18 to which the other end is fixed. In the pressure sensor 1, since the length from one end of the sealing sheet 19 to the other end is longer than the length from one end to the other end of the lower frame member 13 and the upper frame member 18, the sealing sheet 19 is pressed down. It can suppress the stress that sometimes occurs.

The substrate 10 is a flat member made of an insulating resin such as a glass epoxy resin, and has a rectangular planar shape. A first land 11 and a second land 12 are arranged on the substrate 10 . The first land 11 and the second land 12 are formed of a conductive material such as conductive resin and metal foil such as copper foil. The first land 11 has a rectangular planar shape and is arranged at the center of the upper surface of the substrate 10. The first land 11 forms a capacitor together with the conductive member 17. The second land 12 is a flat conductor having a circular planar shape, and is arranged near one corner of the substrate 10 and spaced apart from the first land 11 . The planar shape of the second land 12 may be rectangular or may be a rectangular frame surrounding the first land 11. Further, the second land 12 may be formed of a plurality of flat conductors.

The lower frame member 13 is formed of a frame-shaped synthetic resin such as polyimide resin, and 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 lower frame member 13 is adhered to the upper surface of the substrate 10 via an adhesive sheet 20 made of thermosetting resin.

The lower frame member 13 surrounds the first land 11 and forms, together with the upper frame member 18, a housing portion 131 that accommodates the second land 12, the dielectric member 14, the spacer 15, and the conductive member 17. The lower frame member 13 and the upper frame member 18 constitute an outer frame member. Further, the outer frame member may be a frame member in which the lower frame member 13 and the upper frame member 18 are integrated. Furthermore, the outer frame member may be composed of only the lower frame member 13.

The lower frame member 13 has a through hole 132 and a notch guide 133 formed therein. The through hole 132 is a hole for inserting the connecting member 16 for electrically connecting the second land 12 and the conductive member 17, and is formed to penetrate from the upper surface to the lower surface of the lower frame member 13. . The opening on the lower surface side of the through hole 132 overlaps at least a portion of the second land 12 . The adhesive sheet 20 disposed between the lower frame member 13 and the substrate 10 has an opening formed in a portion where the opening on the lower surface side of the through hole 132 and the second land 12 overlap.

The notch guide 133 is a groove extending diagonally outward from one corner of the inner wall of the lower frame member 13 on the upper surface thereof. The notch guide 133 is fitted with the protrusion 172 of the conductive member 17 to guide the tip of the protrusion 172 to the opening on the upper surface side of the through hole 132 on the upper surface of the lower frame member 13 .

The dielectric member 14 is a flat member made of a ferroelectric material such as barium titanate, and is bonded and arranged on the first land 11 via an adhesive member (not shown) such as silver paste. The relative dielectric constant of the dielectric member 14 is 1000 or more, and the thickness of the dielectric member 14 is 0.2 mm or more. The dielectric member 14 is disposed between the first land 11 and the conductive member 17 forming the capacitor, and increases the capacitance of the capacitor formed by the first land 11 and the conductive member 17.

The spacer 15 is an insulating member having a frame-like planar shape, and is disposed on the dielectric member 14 by being adhered with an adhesive member (not shown) to form a gap that isolates the dielectric member 14 and the conductive member 17. The spacer 15 has a thickness of 0.005 mm or more and 0.5 mm or less. The adhesive member that adheres the spacer 15 to the dielectric member 14 is disposed over the entire lower surface of the spacer 15 .

The connecting member 16 is a cylindrical conductive resin, and is inserted into the through hole 132 to electrically connect the second land 12 and the conductive member 17. The connecting member 16 may have a shape other than a cylinder, such as a cube or a substantially conical shape. Further, the connecting member 16 may be formed by injecting a conductive thermosetting resin paste and a solder paste into the through hole 132, and heating the conductive member 17 after placing the conductive member 17 therein. Note that in the pressure-sensitive sensor according to the embodiment, a through hole may be formed instead of arranging the connecting member 16 to electrically connect the second land 12 and the conductive member 17. In addition, in the pressure-sensitive sensor according to the embodiment, instead of disposing the connecting member 16, the second land 12 is placed on both the side surface and the upper surface of the lower frame member 13 so that the conductive member 17 and the second electrode 104 are electrically connected. It may be placed so as to cover part of the

The conductive member 17 is a flat member made of a flexible material such as conductive rubber, and has a main body portion 171 and a protruding portion 172. The conductive member 17 has a thickness of 0.1 mm or more and 1.0 mm or less. The main body part 171 is disposed on the spacer 15 , and the protruding part 172 extends outward from the main body part 171 , fits into the notch guide 133 and extends to the opening on the upper surface side of the through hole 132 , and the protrusion part 172 extends outward from the main body part 171 . electrically connected to.

When the conductive member 17 is pressed down from above the pressure-sensitive sensor 1 through the sealing sheet 19, the conductive member 17 curves, and the distance between the conductive member 17 and the first land 11 becomes shorter, and the conductive member 17 and The capacitance of the capacitor formed by the first land 11 is increased. Note that when the second land 12 is arranged to cover the side and top surfaces of the lower frame member 13, the protrusion 172 of the conductive member 17 is omitted, and the conductive member 17 is placed between the sealing sheet 19 and the lower frame member 13. The second land 12 may be disposed so as to be electrically connected to the second land 12 by being sandwiched between the second land 12 and the upper surface.

The upper frame member 18, also called a frame sheet, is formed of a frame-shaped synthetic resin such as polyimide resin along the outer periphery of the substrate 10, and is adhered to the upper surface of the lower frame member 13 via an adhesive member (not shown). The upper frame member 18 is bonded to the upper surface of the lower frame member 13, thereby strengthening the fixation of the protrusion 172 to the notch guide 133. In place of the notch guide 133 of the lower frame member 13, the upper frame member 18 may be formed with a notch guide that engages the protrusion 172. Further, the upper frame member 18 may be arranged to surround the conductive member 17. Furthermore, the upper frame member 18 may be formed with a notch guide together with the notch guide 133 of the lower frame member 13. Note that the upper frame member 18 may be integrated with the lower frame member 13.

The sealing sheet 19 is adhered to the upper surface of the upper frame member 18 via an adhesive member (not shown) so as to cover the conductive member 17. The sealing sheet 19 is made of a synthetic resin material that is waterproof and more flexible than polyimide resin, that is, has lower tensile strength. Tensile strength is defined by stress measured according to ASTM D638. The sealing sheet 19 is made of a synthetic resin material such as polyurethane resin, fluororesin, and vinyl resin, which has lower tensile strength than polyimide resin and has thermal properties equivalent to polyimide resin.

Since the sealing sheet 19 seals the accommodating part 131, the first land 11, the second land 12, the dielectric member 14, the spacer 15, and the conductive member 17 accommodated in the accommodating part 131 are dustproof and waterproof. gender is ensured.

A first electrode 102 connected to the first land 11 via a via hole 101 and a second electrode 104 connected to the second land 12 via a via hole 103 are formed on the lower surface of the substrate 10. The first electrode 102 and the second electrode 104 are a pair of detection electrodes that detect changes in the capacitance of the capacitor formed by the first land 11 and the conductive member 17, which changes as the conductive member 17 is pressed down. It is an electrode.

FIG. 2 is a cross-sectional view illustrating the pressed state of the pressure-sensitive sensor 1, FIG. 2(a) is a cross-sectional view of the pressure-sensitive sensor 1 before being pressed, and FIG. 2(b) is a cross-sectional view of the pressure-sensitive sensor 1 while being pressed. FIG.

When the pressure sensor 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 sensor 1 is pressed down from above the sealing sheet 19 by a pressing body 200, such as a finger or a non-dielectric resin pen, the sealing sheet 19 becomes convex downward, and the main body of the conductive member 17 Press down on 171. Since the conductive member 17 is made of flexible conductive rubber, the main body portion 171 curves downward in a convex manner. By convexly curving the main body 171 downward, the distance between the dielectric member 14 and the conductive member 17 becomes d−Δd, which is shorter than the predetermined separation distance, and is formed by the first land 11 and the conductive member 17. The capacitance of the capacitor changes. As the sealing sheet 19 is further pressed down, the lower surface of the conductive member 17 comes into contact with the upper surface of the dielectric member 14 . When the sealing sheet 19 is further pressed down after the lower surface of the conductive member 17 contacts the upper surface of the dielectric member 14, the area of the contact surface where the lower surface of the conductive member 17 and the upper surface of the dielectric member 14 come into contact gradually increases. . As the area of the contact surface where the lower surface of the conductive member 17 and the upper surface of the dielectric member 14 come into contact increases, the capacitance of the capacitor formed by the first land 11 and the conductive member 17 increases. The pressure-sensitive sensor 1 outputs an electric signal from the first electrode 102 and the second electrode 104 that indicates the capacitance of the capacitor that changes when the sealing sheet 19 is pressed down.

(Method for manufacturing a pressure-sensitive sensor according to the first embodiment)
FIG. 3 is a diagram showing a method for manufacturing the pressure-sensitive sensor 1. FIG. 3(a) shows the first step, FIG. 3(b) shows the second step, and FIG. 3(c) shows the third step. 3(d) shows the fourth step.

First, in the first step, a collective lower frame member having a shape in which a plurality of lower frame members are connected via a collective adhesive sheet 22 in 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. 23 is placed. The collective substrate 21 is a single plate material in which a total of six substrates 10 (2×3) are connected, and the upper surface of each substrate 10 has a first land 11 and a second land 12 formed by pattern etching. each is placed. The collective adhesive sheet 22 is an adhesive sheet in which portions corresponding to the first and second lands of each substrate 10 are open. A collective lower frame member 23 is arranged on the collective adhesive sheet 22. The collective lower frame member 23 is a frame member having a shape in which a plurality of lower frame members 13 are connected in the same arrangement as the respective boards 10 of the collective board 21. By arranging the collective substrate 21 and the collective lower frame member 23, a total of six 2×3 boxes 24 are formed. Each box 24 corresponds to a housing section 131 that surrounds the first land 11 and houses the second land 12 , the dielectric member 14 , the spacer 15 , and the conductive member 17 .

Next, in a second step, the dielectric member 14, the spacer 15, the connecting member 16, and the conductive member 17 are arranged in each box 24 formed by the collective substrate 21 and the collective lower frame member 23. The dielectric member 14 is placed on the first land 11, and the spacer 15 is placed on the dielectric member 14 via an adhesive member. The connecting 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 to fit into the notch guide 133.

Next, in a third step, a collective upper frame member 25 having a shape in which a plurality of upper frame members are connected is arranged, and further a collective sealing sheet 26 in a shape in which a plurality of sealing sheets are connected is arranged via an adhesive member. , a collective pressure-sensitive sensor 27 is formed in which the pressure-sensitive sensors 1 are connected. The collective pressure-sensitive sensor 27 is subjected to heat treatment for thermosetting the adhesive member or adhesive sheet and melting the conductive thermosetting resin paste and solder paste used for the connecting member 16.

Then, in the fourth step, the collective substrate is cut. The collective pressure-sensitive sensor 27 is cut as shown by the broken line in FIG. 3(d), and a total of six pressure-sensitive sensors 1 (2×3) are formed.

(Operations and effects of the pressure-sensitive sensor according to the first embodiment)
In the pressure-sensitive sensor 1, the sealing sheet 19 is made of a material that is more flexible than polyimide resin. The stress can be smaller than that generated in a sealing sheet with the same stress. Since the stress generated in the sealing sheet 19 is reduced, the pressure-sensitive sensor 1 can have higher detection sensitivity than a pressure-sensitive sensor having a sealing sheet made of polyimide resin and having the same thickness.

(Modified example of the pressure-sensitive sensor according to the first embodiment)
In the pressure-sensitive sensor 1, the detection sensitivity is improved by forming the sealing sheet 19 from a highly flexible material, but in the pressure-sensitive sensor according to the embodiment, the detection sensitivity is improved by other aspects. It's okay. In the pressure-sensitive sensor according to the embodiment, when the sealing sheet is pressed down from above, the displacement of the conductive member that is pressed down through the sealing sheet is measured. By using a displacement adjusting member to adjust, the detection sensitivity of the pressure sensor may be improved.

For example, in the pressure-sensitive sensor according to the embodiment, the length from one end of the sealing sheet to the other end is such that one end of the outer frame member to which one end of the sealing sheet is fixed and the other end of the sealing sheet to which the other end is fixed. It may be longer than the length to the other end of the outer frame member. The sealing sheet functions as a displacement adjustment member that adjusts the displacement of the conductive member by making the length longer than the length of the outer frame member.

FIG. 4(a) is a cross-sectional view of a pressure-sensitive sensor according to a first modification, and FIG. 4(b) is a cross-sectional view of a pressure-sensitive sensor according to a second modification. The cross-sectional views shown in FIGS. 4(a) and 4(b) correspond to the cross-sectional view taken along line AA' shown in FIG. 1(a).

The pressure-sensitive sensor 2 is different from the pressure-sensitive sensor 1 in that it has a sealing sheet 31 instead of the sealing sheet 19. The configurations and functions of the components of the pressure-sensitive sensor 2 other than the sealing sheet 31 are the same as the configurations and functions of the components of the pressure-sensitive sensor 1 denoted by the same reference numerals, so detailed explanations will be omitted here.

The sealing sheet 31 is adhered to the upper surface of the upper frame member 18 via an adhesive member (not shown) so as to cover the conductive member 17. The sealing sheet 31 is a sheet material made of polyimide resin and having a rectangular planar shape. The sealing sheet 31 may be formed of a synthetic resin material having a tensile strength lower than that of polyimide resin and having thermal properties equivalent to that of polyimide resin, or may be formed of nylon resin. The sealing sheet 31 is arranged so that the length of one side is longer than the length of one side of the outer edges of the substrate 10, the lower frame member 13, and the upper frame member 18, and the outer edge matches the outer edge of the upper frame member 18. Ru.

Since the sealing sheet 31 is arranged so that the length of one side is longer than the length of one side of the outer edge of the upper frame member 18 and the outer edge matches the outer edge of the upper frame member 18, the central part 311 is recessed and conductive. It is arranged so as to be close to the upper surface of the member 17.

The method for manufacturing the pressure-sensitive sensor 2 is the same as the method for manufacturing the pressure-sensitive sensor 1, so a detailed explanation will be omitted here.

Since the pressure sensor 2 is longer than the length from one end of the upper frame member 18 to which one end of the sealing sheet 31 is fixed to the other end of the upper frame member 18 to which the other end of the sealing sheet 31 is fixed, the pressure sensor 2 cannot be pressed. It is possible to suppress the stress that occurs when The pressure-sensitive sensor 2 can improve detection sensitivity by suppressing stress generated in the sealing sheet 31 when pressed.

The pressure-sensitive sensor 3 is different from the pressure-sensitive sensor 2 in that it has a sealing sheet 33 instead of the sealing sheet 31. The configurations and functions of the components of the pressure-sensitive sensor 3 other than the sealing sheet 33 are the same as the configurations and functions of the components of the pressure-sensitive sensor 2 to which the same reference numerals are attached, so detailed explanations will be omitted here.

The sealing sheet 33 is formed of polyimide resin and has a central portion 331, a connecting portion 332, and an outer peripheral portion 333. The central portion 331 has a rectangular planar shape, and is arranged so as to be farther away from the conductive member 17 than the outer peripheral portion 333 due to the connecting portion 332 . The thickness of the connecting portion 332 is thinner than the thickness of the central portion 331 and the outer peripheral portion 333. The connecting portion 332 extends from the inner edge of the central portion 331 to the outer edge of the central portion 331 so as to be located inwardly as the connection portion 332 becomes further away from the outer peripheral portion 333, and connects the outer edge of the central portion 331 and the inner edge of the outer peripheral portion 333. It is arranged so that The outer peripheral portion 333 has a frame-like planar shape, and its outer edge is adhered to the upper surface of the upper frame member 18. The thickness of the outer peripheral part 333 is the same as the thickness of the central part 331.

In the method for manufacturing the pressure-sensitive sensor 3, reflow is performed before arranging the collective sealing sheet including the plurality of sealing sheets 33. The collective sealing sheet including the plurality of sealing sheets 33 is adhered to the upper surface of the collective upper frame member 25 after reflow. By adhering the collective sealing sheet after reflowing, the structure of the sealing sheet 33 in which the central portion 331 is swollen is prevented from being deformed by reflowing.

Since the pressure-sensitive sensor 3 has the connecting portion 332 where the sealing sheet 33 is thin, stress generated when the sealing sheet 33 is pressed down can be suppressed. The pressure-sensitive sensor 3 can improve detection sensitivity by suppressing stress generated in the sealing sheet 33 when the sealing sheet 33 is pressed down.

In addition, in the pressure-sensitive sensor 3, the sealing sheet 33 bends when pressed down, thereby dispersing the stress generated in the sealing sheet 33 and bonding the upper frame member 18 and the sealing sheet 33. There is a low possibility that the bonded portion will peel off, and there is also a low possibility that the sealing sheet 33 will be damaged. On the other hand, in the pressure-sensitive sensor 3, since the sealing sheet 33 seals the accommodating part, air does not flow into the accommodating part from the outside, and dustproof and waterproof properties are maintained.

In the pressure-sensitive sensor 3, the connecting portion between the central portion 331 and the connecting portion 332 and the connecting portion between the outer circumferential portion 333 and the connecting portion 332 are formed in an angular shape. In the pressure-sensitive sensor according to this embodiment, the connection portion between the center portion, the connection portion, and the outer circumferential portion may have an arc shape. Further, the central portion 331 may be partially proximate to the upper surface of the conductive member 17 by being depressed by the weight of the sealing sheet 33 . Furthermore, the outer peripheral portion 33 may be close to the upper surface of the conductive member 17 similarly to the central portion 331.

(Configuration and function of pressure-sensitive sensor of second embodiment)
FIG. 5 is an exploded perspective view of the pressure-sensitive sensor according to the second embodiment.

The pressure-sensitive sensor 4 is different from the pressure-sensitive sensor 1 in that it has a spacer 45 instead of the spacer 15. The configurations and functions of the components of the pressure-sensitive sensor 4 other than the spacer 45 are the same as the configurations and functions of the components of the pressure-sensitive sensor 1 denoted by the same reference numerals, so detailed explanations will be omitted here. The spacer 45 differs from the spacer 15 in that an opening 46 is formed on one side of the frame shape. The opening 46 is a portion where the center of one side of the spacer 45 is missing. The structure and function of the spacer 45 other than the formation of the opening 46 are the same as the structure and function of the spacer 15, so detailed description thereof will be omitted here. Further, since the method for manufacturing the pressure-sensitive sensor 4 is the same as the method for manufacturing the pressure-sensitive sensor 1, detailed explanation will be omitted here. In this embodiment, the opening is arranged at the center of one side of the spacer 45, but it may be arranged at a location other than the center.

(Operations and effects of the pressure-sensitive sensor according to the second embodiment)
In the pressure-sensitive sensor 1, the area surrounded by the spacer 15 between the dielectric member 14 disposed below the spacer 15 and the conductive member 17 disposed above the spacer 15 includes the dielectric member 14, the spacer 15, and It is sealed by a conductive member 17. In the pressure sensor 1, the area surrounded by the spacer 15 is sealed by the dielectric member 14, the spacer 15, and the conductive member 17, so that the conductive member 17 that is pressed down through the sealing sheet 19 is not pressed down after it is no longer pressed down. It takes time to return to the position before being pressed.

On the other hand, in the pressure-sensitive sensor 4, the spacer 45 has an opening 46 formed therein, so that the area surrounded by the spacer 45 allows air to flow in from the outside through the opening 46 and Air flows outside. In the pressure sensor 4, air flows in and out of the area surrounded by the spacer 45 through the opening 46, so that the conductive member 17 that has been pressed down through the sealing sheet 19 is no longer pressed down. The time it takes to return to the previous position is shorter than that of the pressure-sensitive sensor 1.

(Modified example of pressure-sensitive sensor according to second embodiment)
FIG. 6 is an exploded perspective view of a pressure-sensitive sensor according to a third modification example, which is a modification example of the pressure-sensor according to the second embodiment.

The pressure-sensitive sensor 5 differs from the pressure-sensitive sensor 4 in that it has a spacer 55 instead of the spacer 45. The configurations and functions of the components of the pressure-sensitive sensor 5 other than the spacer 55 are the same as those of the pressure-sensitive sensor 4, which are denoted by the same reference numerals, so detailed explanations will be omitted here. The spacer 55 differs from the spacer 45 in that an opening 56 is formed on one frame-shaped side instead of the opening 46 . The structure and function of the spacer 55 other than the formation of the opening 56 are the same as the structure and function of the spacer 45, so a detailed description thereof will be omitted here. Further, since the method of manufacturing the pressure-sensitive sensor 5 is the same as the method of manufacturing the pressure-sensitive sensor 1, detailed explanation will be omitted here.

The opening 46 formed in the spacer 45 is formed so as to cut one side of the spacer 45, but the opening 56 faces the dielectric member 14 on one side of the spacer 55 without cutting one side of the spacer 55. This is a recess formed by recessing the center of the surface. The opening may be formed by recessing the center of the surface of one side of the spacer 55 that faces the conductive member 17; By forming the concave portion in the spacer 55, an opening 56 is formed on the surface facing the dielectric member 14, and the surface facing the conductive member 17 becomes flat, so that the conductive member 17 is repeatedly pressed down to form the opening 56. 56 corners will not be cut off. Further, two or more openings may be formed, and may be formed on both the surface of the spacer facing the dielectric member 14 and the surface facing the conductive member 17.

FIG. 7 is an exploded perspective view of a pressure-sensitive sensor according to a fourth modification example, which is a modification example of the pressure-sensor according to the second embodiment.

The pressure-sensitive sensor 6 is different from the pressure-sensitive sensor 4 in that it has a first spacer 65a and a second spacer 65b instead of the spacer 45. The configurations and functions of the components of the pressure-sensitive sensor 6 other than the first spacer 65a and the second spacer 65b are the same as those of the pressure-sensitive sensor 4 with the same reference numerals, so detailed explanations will be omitted here. .

The first spacer 65a has a frame-like shape and is arranged between the conductive member 17 and the second spacer 65b such that its upper surface faces the lower surface of the conductive member 17. The first spacer 65a does not have an opening that allows air to flow into and out of the area surrounded by the first spacer 65a and the second spacer 65b.

Similarly to the spacer 45, the second spacer 65b has an opening 66 formed on one side of the frame shape, and is arranged between the dielectric member 14 and the first spacer 65a so as to overlap the first spacer 65a. Furthermore, the outer edge of the second spacer 65b matches the outer edge of the first spacer 65a, and the inner edge of the second spacer 65b projects inward than the inner edge of the first spacer 65a. Note that in this embodiment, the outer edge of the second spacer 65b is made to match the outer edge of the first spacer 65a, but the outer edges do not have to match.

Since the inner edge of the second spacer 65b protrudes more inward than the inner edge of the first spacer 65a, the inner edge of the first spacer 65a does not contact the dielectric member 14 but contacts the upper surface of the second spacer 65b. Since the second spacer 65b is arranged between the first spacer 65a and the dielectric member 14, even if the conductive member 17 is scraped off between the inner edge of the first spacer 65a and scraps are generated, the second spacer 65b is disposed between the first spacer 65a and the dielectric member 14. Due to the thickness of the conductive member 17 and the dielectric member 14, there is a low possibility that a short circuit may occur between the conductive member 17 and the dielectric member 14 via shavings, resulting in malfunction. Note that the opening 66 may be formed in both the first spacer 65a and the second spacer 65b. When the opening 66 is formed in both the first spacer 65a and the second spacer 65b, the first spacer 65a and the second spacer 65b are larger than the first spacer 65b when the first spacer 65a and the second spacer 65b are viewed from above. 65a and the opening 66 of the second spacer 65b are preferably arranged so as not to overlap each other. By arranging the first spacer 65a and the second spacer 65b so that the openings 66 do not overlap, the dielectric member 14 is not exposed at the opening 66, and the dielectric member 14 is conductive through the shavings generated at the opening. There is a low possibility that the member 17 will be short-circuited and malfunction. Further, the first spacer 65a and the second spacer 65b may be arranged so that, when the first spacer 65a and the second spacer 65b are viewed from above, a portion of the opening 66 formed therein overlaps. The width at which the openings 66 formed in each of the first spacer 65a and the second spacer 65b overlap is the width of the accumulation of shavings scraped off in the opening 66 of the first spacer 65a and the width of the opening 66 of the second spacer 65b. It is preferable that the width is wider than the sum of the accumulated widths of the shavings scraped off. By making the overlap width of the openings 66 wider than the sum of the accumulated widths of the shavings scraped off in the openings 66 of the first spacer 65a and the second spacer 65b, the shavings scraped off on both openings 66 are There is less possibility that the dielectric member 14 and the conductive member 17 will contact each other and cause a short circuit and malfunction.

The first spacer 65a is arranged between the conductive member 17 and the second spacer 65b, but may be arranged between the dielectric member 14 and the second spacer 65b. When the first spacer 65a is disposed between the dielectric member 14 and the second spacer 65b, the first spacer 65a is formed such that its inner edge protrudes inward than the inner edge of the second spacer 65b. Since the first spacer 65a in which a frame-shaped opening on one side is not formed is arranged between the second spacer 65b and the dielectric member 14, the dielectric member 14 is disposed at the inner edge and the opening 66 of the second spacer 65b. There is a low possibility that the dielectric member 14 and the conductive member 17 will short-circuit through the scraps that are not exposed and are scraped off by the second spacer 65b, resulting in malfunction.

Note that the pressure-sensitive sensors 4 to 6 have the

spacers

45, 55, and 65b in which the

openings

46, 56, and 66 are formed, respectively, so that the area surrounded by the

spacers

45, 55, 65a, and 65b is protected from the atmosphere. Enables inflow and outflow. However, in the pressure-sensitive sensor according to the embodiment, the spacer 15 in which no opening is formed is used, and the opening through which the atmosphere can flow into and out of the area surrounded by the spacer 15 is formed between the dielectric member 14, the conductive member 17, and the spacer 15. It may be formed between

In the pressure-sensitive sensor according to the embodiment, the adhesive member that adheres the spacer 15 to the dielectric member 14 is not disposed over the entire lower surface of the spacer 15, but is disposed only on a part of the lower surface of the spacer 15, so that An opening may be formed in a region surrounded by the spacer 15 through which air can flow in and out. Furthermore, in the pressure-sensitive sensor according to the embodiment, by peeling off a part of the adhesive member disposed over the entire lower surface of the spacer 15, an opening through which air can flow into and out of the area surrounded by the spacer 15 is created. may be formed.

(Configuration and function of pressure-sensitive sensor of third embodiment)
FIG. 8 is a cross-sectional view of a pressure-sensitive sensor according to the third embodiment. The cross-sectional view shown in FIG. 8 is a cross-sectional view corresponding to the cross-sectional view taken along the line AA' shown in FIG. 1(a).

The pressure-sensitive sensor 7 is different from the pressure-sensitive sensor 1 in that it has a spacer 75 instead of the spacer 15. The configurations and functions of the components of the pressure-sensitive sensor 7 other than the spacer 75 are the same as the configurations and functions of the components of the pressure-sensitive sensor 1 denoted by the same reference numerals, so detailed explanations will be omitted here. Further, since the method of manufacturing the pressure sensor 7 is the same as the method of manufacturing the pressure sensor 1, detailed explanation will be omitted here.

The spacer 75 has a hard layer 751 and a soft layer 752. The hard layer 751 is an insulating member made of synthetic resin such as polyimide resin and having a frame-like planar shape, and is arranged on the dielectric member 14 .

The soft layer 752 is a sticky adhesive layer that is arranged to match the outer edge of the hard layer 751 and adheres the hard layer 751 and the conductive member 17. In one example, the hard layer 751 has a thickness of 25 μm, and the soft layer 752 has a thickness of 10 μm.

The soft layer 752 is an adhesive insulating member having a frame-like planar shape and made of a synthetic resin such as acrylic resin that has a lower hardness than the polyimide resin forming the hard layer 751. Further, the hardness of the hard layer 751 and the soft layer 752 is lower than that of the dielectric member 14. The hardness of the constituent members of the pressure-sensitive sensor 1, such as the dielectric member 14, the hard layer 751, the soft layer 752, and the conductive member 17, is defined by Rockwell hardness measured based on ASTM D785.

(Operations and effects of the pressure-sensitive sensor according to the third embodiment)
In the pressure-sensitive sensor 7, since the soft layer 752, which has a lower hardness than the hard layer 751, is in contact with the conductive member 17, the shavings generated by scraping the conductive member 17 are stacked on the dielectric member 14, and the conductive member 17 and the dielectric There is little risk of short circuit with the member 14 and malfunction. In the pressure sensor 4, the conductive member 17 comes into contact with the opening 46 of the spacer 45 when it is pressed down and sinks into the area surrounded by the spacer 45. In the pressure-sensitive sensor 4, there is a risk that shavings may be generated due to repeated contact of the conductive member 17 with the opening 46 of the spacer 45 over a long period of time. Since the soft layer 752, which has a low resistance, is in contact with the conductive member 17, the generation of shavings is suppressed. In addition, in the pressure-sensitive sensor 7, the hard layer 751 is disposed between the dielectric member 14 and the soft layer 752, so that even if the thickness of the soft layer 752 changes due to long-term use of the pressure-sensitive sensor, the hard layer 751 is arranged between the dielectric member 14 and the soft layer 752. By arranging the layer 751, a necessary distance between the conductive member 17 and the dielectric member 14 can be secured. Further, the soft layer 752 does not come into contact with the dielectric member 14, and the soft layer 752 can be prevented from being scraped off by the dielectric member 14.

FIG. 9(a) is a sectional view showing the pressure-sensitive sensor 1 in the pressed state according to the first embodiment, and FIG. 9(b) is a sectional view showing the pressure-sensitive sensor 7 in the pressed state.

In the pressure-sensitive sensor 1, each time the pressing body 200 presses down the conductive member 17 through the sealing sheet 19, the upper part 351 of the inner wall of the spacer 15 that contacts the conductive member 17 scrapes the contact portion with the conductive member 17, There is a possibility that shavings 352 may be generated due to repeated pressing of the conductive member 17. When the pressure-sensitive sensor 1 is pressed repeatedly about one million times, shavings 352 are stacked on the surface of the dielectric member 14, causing a short circuit between the conductive member 17 and the dielectric member 14, and malfunctioning. There is a risk.

On the other hand, in the pressure-sensitive sensor 7 according to the embodiment, in response to the presser 200 pressing down the conductive member 17 via the sealing sheet 19, the soft layer 752 having low hardness and adhesiveness curves together with the conductive member 17. Therefore, there is a low possibility that the conductive member 17 will be scraped by the spacer 75. In the pressure sensor 7, there is a low possibility that the conductive member 17 will be scraped by the spacer 75 due to repeated pressing, so conductive scraps will be stacked on the dielectric member 14, causing a short circuit between the conductive member 17 and the dielectric member 14. This reduces the risk of malfunctions and extends the lifespan.

Furthermore, in the pressure-sensitive sensor 7, the hardness of the hard layer 751 is lower than the hardness of the dielectric member 14 and higher than the hardness of the soft layer 752. In the pressure-sensitive sensor 7 according to the embodiment, since the dielectric member 14 and the hard layer 751, which have relatively high hardness, are arranged adjacent to each other, the durability is increased and the service life can be extended.

(Modified example of pressure-sensitive sensor according to third embodiment)
In the pressure-sensitive sensor 7, the soft layer 752 is an adhesive layer that adheres the hard layer 751 and the conductive member 17, but in the pressure-sensitive sensor according to the embodiment, the soft layer is made of resin that forms the hard layer 751. If the hardness is low, it may not be an adhesive layer.

Furthermore, in the pressure-sensitive sensor 7, the hard layer 751 is made of polyimide resin, but in the pressure-sensitive sensor according to the embodiment, the hard layer is made of a resin other than polyimide resin if it has higher hardness than the soft layer 752. may be formed.

Further, in the pressure-sensitive sensor 7, the thickness of the soft layer 752 is thinner than the thickness of the hard layer 751, but in the pressure-sensitive sensor according to the embodiment, the thickness of the soft layer is thicker than the thickness of the hard layer. They may be the same. In the pressure-sensitive sensor according to the embodiment, by making the thickness of the soft layer thicker than the thickness of the hard layer, when the conductive member 17 is pressed down, the hard layer becomes difficult to scrape the conductive member. Generation of dregs can be suppressed.

Claims

A substrate and
a conductive first land disposed on the substrate;
a conductive second land arranged on the substrate so as to be insulated from the first land;
a dielectric member disposed on the first land;
a spacer disposed on the dielectric member;
a flexible conductive member disposed on the spacer and connected to the second land;
an outer frame member that is disposed on the substrate and forms, together with the substrate, a housing portion that accommodates the first land, the second land, the dielectric member, the spacer, and the conductive member;
a sealing sheet fixed on the outer frame member and sealing the accommodating part;
a first electrode electrically connected to the first land;
a second electrode electrically connected to the second land,
The length from one end of the sealing sheet to the other end is one end of the outer frame member to which one end of the sealing sheet is fixed and the other end of the outer frame member to which the other end of the sealing sheet is fixed. A pressure-sensitive sensor characterized by a length that is longer than the previous length.
The sealing sheet is
an outer peripheral portion fixed on the outer frame member;
a central portion surrounded by the outer peripheral portion and arranged farther from the conductive member than the outer peripheral portion;
The pressure-sensitive sensor according to claim 1, further comprising a connecting portion extending from an inner edge of the outer peripheral portion toward an outer edge of the central portion and connecting the outer peripheral portion and the central portion.
The pressure-sensitive sensor according to claim 2, wherein the thickness of the connecting portion is thinner than the thickness of the central portion and the outer peripheral portion.
A substrate and
a conductive first land disposed on the substrate;
a conductive second land arranged on the substrate so as to be insulated from the first land;
a dielectric member disposed on the first land;
a spacer disposed on the dielectric member;
a flexible conductive member disposed on the spacer and connected to the second land;
an outer frame member that is disposed on the substrate and forms, together with the substrate, a housing portion that accommodates the first land, the second land, the dielectric member, the spacer, and the conductive member;
a sealing sheet fixed on the outer frame member and sealing the accommodating part;
a first electrode electrically connected to the first land;
a second electrode electrically connected to the second land,
An opening through which air can flow in and out is formed in a region surrounded by the spacer.
A pressure-sensitive sensor characterized by:
The spacer has a frame-like shape with a part missing,
The pressure-sensitive sensor according to claim 4, wherein the opening is a missing portion of the spacer.
The spacer has a frame-like shape with a recess formed in either a surface facing the dielectric member or a surface facing the conductive member,
The pressure-sensitive sensor according to claim 4, wherein the opening is the recess.
The spacer is
a first spacer arranged between the dielectric member and the conductive member and having a frame-like shape;
a second spacer arranged to overlap the first spacer;
The pressure-sensitive sensor according to any one of claims 4 to 6, comprising:
the second spacer is disposed between the dielectric member and the first spacer,
the first spacer is a soft layer;
The second spacer includes a hard layer made of a material with higher hardness than the soft layer;
The pressure-sensitive sensor according to claim 7, comprising:
the second spacer is disposed between the dielectric member and the first spacer,
The pressure-sensitive sensor according to claim 7 or 8, wherein an inner edge of the second spacer projects more inward than an inner edge of the first spacer.
The pressure-sensitive sensor according to claim 7 or 8, wherein the second spacer has a frame-like shape with a portion missing.
Both the first spacer and the second spacer have a frame-like shape with a part missing,
The spacer according to claim 7 or 8, wherein the first spacer and the second spacer are arranged so that the missing portions do not overlap each other when the first spacer and the second spacer are viewed in plan. pressure sensor.
Both the first spacer and the second spacer have a frame-like shape with a part missing,
The first spacer and the second spacer are arranged so that a part of the missing portion overlaps when the first spacer and the second spacer are viewed from above. Pressure sensor.