Pressure sensor

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

[0001] The present disclosure relates to pressure-sensitive sensors.

[0002] Pressure-sensitive sensors are known that are mounted as operation switches on mobile communication devices such as smartphones and electronic devices such as pen tablets. For example, Japanese Patent Application Laid-Open No. 2020-123481 describes a pressure-sensitive sensor in which a housing that houses a dielectric member and a flexible conductive member arranged adjacent to the dielectric member via a spacer is sealed with a sealing sheet. By sealing the housing that houses the dielectric member and the conductive member with a sealing sheet, the dustproofness and waterproofness of the dielectric member and the conductive member can be improved, and a decrease in detection accuracy due to contamination of the dielectric member and the conductive member can be prevented.

[0003] However, in the pressure-sensitive sensor described in JP 2020-123481 A, the sealing sheet is formed from a resin with low flexibility such as polyimide resin, so part of the pressing force pressing down on the conductive member through the sealing sheet is absorbed by the sealing sheet, which may result in a decrease in detection sensitivity.

[0004] An object of the present disclosure is to provide a pressure sensor that has excellent dustproof and waterproof properties and high detection sensitivity.

[0005] The pressure-sensitive sensor according to the present disclosure 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 accommodating section for 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 accommodating section, a first electrode electrically connected to the first land, and a second electrode electrically connected to the second land, and the length from one end to the other end of the sealing sheet is longer than the length from one end of the outer frame member to which 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.

[0006] In the pressure-sensitive sensor according to the present disclosure, the sealing sheet preferably has an outer peripheral portion fixed on an outer frame member, a central portion surrounded by the outer peripheral portion and positioned farther away from the conductive member than the outer peripheral portion, and a connecting portion extending from the inner edge of the outer peripheral portion toward the outer edge of the central portion and connecting the outer peripheral portion and the central portion.

[0007] In the pressure-sensitive sensor according to the present disclosure, the thickness of the connection portion is preferably thinner than the thickness of the central portion and the outer peripheral portion.

[0008] In addition, the pressure-sensitive sensor according to the present disclosure 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, a storage section 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 storage section, a first electrode electrically connected to the first land, and a second electrode electrically connected to the second land, and an opening is formed in the area surrounded by the spacer to allow air to flow in and out.

[0009] In the pressure-sensitive sensor according to the present disclosure, it is preferable that the spacer has a frame-like shape with a portion missing, and the opening is the missing portion of the spacer.

[0010] In the pressure-sensitive sensor according to the present disclosure, the spacer preferably has a frame-like shape with a recess formed on either the surface facing the dielectric member or the surface facing the conductive member, and the opening is preferably a recess.

[0011] In the pressure-sensitive sensor according to the present disclosure, it is preferable that the spacer has a first spacer arranged between the dielectric member and the conductive member and having a frame-like shape, and a second spacer arranged so as to overlap the first spacer.

[0012] In the pressure-sensitive sensor according to the present disclosure, the second spacer is disposed between the dielectric member and the first spacer, and the first spacer is preferably a soft layer, and the second spacer preferably has a hard layer formed of a material harder than the soft layer.

[0013] 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 further inward than the inner edge of the first spacer.

[0014] In the pressure-sensitive sensor according to the present disclosure, the second spacer preferably has a frame-like shape with a portion missing.

[0015] In the pressure-sensitive sensor according to the present disclosure, both the first spacer and the second spacer have a frame-like shape with portions missing, and it is preferable that 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 a plane.

[0016] 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 portion missing, and it is preferable that the first spacer and the second spacer are arranged so that a portion of the missing portion overlaps when the first spacer and the second spacer are viewed in a plane.

[0017] According to the present disclosure, the pressure sensor can have excellent dustproof and waterproof properties and high detection sensitivity.

[0018] 1A and 1B are diagrams showing a pressure-sensitive sensor according to a first embodiment, where (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 cross-sectional view taken along the line A-A' in (a). Cross-sections illustrating the pressed-down state of the pressure-sensitive sensor shown in FIG. 1, where (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 during pressing. Diagrams showing a method for manufacturing the pressure-sensitive sensor shown in FIG. 1, where (a) shows a first step, (b) shows a second step, (c) shows a third step, and (d) shows a fourth step. (a) is a cross-sectional view of a pressure-sensitive sensor according to a first modified example, and (b) is a cross-sectional view of a pressure-sensitive sensor according to a second modified example. An exploded perspective view of a pressure-sensitive sensor according to a third modified example. An exploded perspective view of a pressure-sensitive sensor according to a fourth modified example. A cross-sectional view of a pressure-sensitive sensor according to a third modified example. 1A is a cross-sectional view showing a pressed state of the pressure-sensitive sensor according to the first embodiment, and FIG. 1B is a cross-sectional view showing a pressed state of the pressure-sensitive sensor according to the third embodiment.

[0019] 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 the embodiments, but extends to the inventions set forth in the claims and their equivalents.

[0020] (Configuration and function of pressure-sensitive sensor of first embodiment) Figure 1 shows a pressure-sensitive sensor of the first embodiment, where Figure 1(a) is an oblique view of the pressure-sensitive sensor, Figure 1(b) is an exploded oblique view of the pressure-sensitive sensor, and Figure 1(c) is a cross-sectional view along line A-A' shown in Figure 1(a).

[0021] The pressure-sensitive sensor 1 includes a substrate 10, first lands 11, second lands 12, a lower frame member 13, a dielectric member 14, a spacer 15, a connecting member 16, a conductive member 17, an upper frame member 18, and a sealing sheet 19. In the pressure-sensitive sensor 1, the substrate 10 to the sealing sheet 19 are bonded together by heating through reflow, and therefore each of the substrate 10 to the sealing sheet 19 has heat resistance that can withstand the heat caused by reflow. In addition, in the pressure-sensitive sensor 1, the length from one end to the other end of the sealing sheet 19 is longer than the length from one end of the lower frame member 13 and the upper frame member 18 to which one end of the sealing sheet 19 is fixed to the other end of the lower frame member 13 and the upper frame member 18 to which the other end of the sealing sheet 19 is fixed. In the pressure sensor 1, the length from one end to the other end of the sealing sheet 19 is longer than the length from one end to the other end of the lower frame member 13 and the upper frame member 18, so that the stress generated when the sealing sheet 19 is pressed down can be suppressed.

[0022] The substrate 10 is a flat plate-like member formed of an insulating resin such as 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 conductor, such as a conductive resin and a metal foil such as copper foil. The first land 11 has a rectangular planar shape and is arranged in 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, separated from the first land 11. The planar shape of the second land 12 may be rectangular, or may be a rectangular frame shape surrounding the first land 11. The second land 12 may also be formed of a plurality of flat conductors.

[0023] The lower frame member 13 is formed of a frame-shaped synthetic resin such as polyimide resin, and is disposed on the upper surface of the substrate 10 so as to surround the first lands 11 and cover the second lands 12. The lower frame member 13 is adhered to the upper surface of the substrate 10 via an adhesive sheet 20 made of a thermosetting resin.

[0024] The lower frame member 13 surrounds the first lands 11 and forms, together with the upper frame member 18, an accommodation portion 131 that accommodates the second lands 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. The outer frame member may also be a frame member formed by integrating the lower frame member 13 and the upper frame member 18. Furthermore, the outer frame member may also be formed by the lower frame member 13 alone.

[0025] 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 a connection member 16 for electrically connecting the second land 12 and the conductive member 17, and is formed so as to penetrate from the upper surface to the lower surface of the lower frame member 13. The opening on the lower surface of the through hole 132 overlaps with at least a portion of the second land 12. The adhesive sheet 20, which is disposed between the lower frame member 13 and the substrate 10, has an opening formed in the portion where the opening on the lower surface of the through hole 132 overlaps with the second land 12.

[0026] The notch guide 133 is a groove that extends diagonally outward from one corner of the inner wall of the lower frame member 13 on the upper surface. The notch guide 133 fits into the protrusion 172 of the conductive member 17, thereby guiding the tip of the protrusion 172 to the opening on the upper surface of the through hole 132 on the upper surface of the lower frame member 13.

[0027] The dielectric member 14 is a flat plate-shaped member made of a ferroelectric material such as barium titanate, and is arranged on the first land 11 by being adhered via an adhesive material (not shown) such as silver paste. The 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 arranged between the first land 11 and the conductive member 17, which form a capacitor, and increases the capacitance of the capacitor formed by the first land 11 and the conductive member 17.

[0028] The spacer 15 is an insulating member having a frame-like planar shape, and is arranged on the dielectric member 14 by being adhered with an adhesive member (not shown), forming a gap that separates the dielectric member 14 from 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 arranged over the entire lower surface of the spacer 15.

[0029] The connecting member 16 is a cylindrical conductive resin that 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 generally cone. The connecting member 16 may also be formed by injecting a conductive thermosetting resin paste and a solder paste into the through-hole 132, disposing the conductive member 17, and then heating the resulting mixture. In the pressure-sensitive sensor according to the embodiment, the second land 12 and the conductive member 17 may be electrically connected by forming a through-hole instead of disposing the connecting member 16. In the pressure-sensitive sensor according to the embodiment, the second land 12 may be disposed so as to cover a portion of both the side surface and the top surface of the lower frame member 13, so as to establish electrical continuity between the conductive member 17 and the second electrode 104, instead of disposing the connecting member 16.

[0030] Conductive member 17 is a flat plate-shaped member made of a flexible material such as conductive rubber, and has a main body 171 and a protruding portion 172. Conductive member 17 has a thickness of 0.1 mm or more and 1.0 mm or less. Main body 171 is disposed on spacer 15, and protruding portion 172 extends outward from main body 171, fits into notched guide 133, extends to the opening on the upper surface of through-hole 132, and is electrically connected to connection member 16.

[0031] The conductive member 17 bends in response to being pressed down from above the pressure-sensitive sensor 1 via the sealing sheet 19, shortening the distance between the conductive member 17 and the first land 11 and increasing the capacitance of the capacitor formed by the conductive member 17 and the first land 11. When the second land 12 is arranged so as to cover the side and top surface of the lower frame member 13, the protrusion 172 of the conductive member 17 may be omitted, and the conductive member 17 may be arranged so as to be sandwiched between the sealing sheet 19 and the top surface of the lower frame member 13, thereby establishing electrical conduction between the conductive member 17 and the second land 12.

[0032] The upper frame member 18, also referred to as a frame sheet, is formed of a frame-shaped synthetic resin such as polyimide resin that fits around 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). By adhering the upper frame member 18 to the upper surface of the lower frame member 13, the fixation of the protrusions 172 to the notch guides 133 is strengthened. The upper frame member 18 may be formed with notch guides that engage with the protrusions 172 instead of the notch guides 133 of the lower frame member 13. The upper frame member 18 may also be arranged to surround the conductive member 17. Furthermore, the upper frame member 18 may be formed with notch guides together with the notch guides 133 of the lower frame member 13. The upper frame member 18 may be integrated with the lower frame member 13.

[0033] 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 has higher flexibility than polyimide resin, i.e., lower tensile strength. The tensile strength is defined by stress measured based on ASTM D638. The sealing sheet 19 is made of a synthetic resin material such as polyurethane resin, fluorine-based resin, or vinyl-based resin that has lower tensile strength than polyimide resin but thermal properties equivalent to those of polyimide resin.

[0034] By sealing the accommodating portion 131 with the sealing sheet 19, the first land 11, the second land 12, the dielectric member 14, the spacer 15, and the conductive member 17 accommodated in the accommodating portion 131 are ensured to be dustproof and waterproof.

[0035] A first electrode 102 connected to the first land 11 through a via hole 101, and a second electrode 104 connected to the second land 12 through 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 a change in the capacitance of the capacitor formed by the first land 11 and the conductive member 17, which changes in response to the conductive member 17 being pressed down.

[0036] 2A and 2B are cross-sectional views illustrating the pressed state of the pressure-sensitive sensor 1, with FIG. 2A being a cross-sectional view of the pressure-sensitive sensor 1 before being pressed, and FIG. 2B being a cross-sectional view of the pressure-sensitive sensor 1 during being pressed.

[0037] When the pressure-sensitive 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-sensitive sensor 1 is pressed down from above on the sealing sheet 19 by a presser 200, such as a finger or a non-dielectric resin pen, the sealing sheet 19 becomes convex downward and presses down the main body 171 of the conductive member 17. Because the conductive member 17 is formed of flexible conductive rubber, the main body 171 curves convexly downward. As the main body 171 curves convexly 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 the capacitance of the capacitor formed by the first land 11 and the conductive member 17 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 comes into contact with the upper surface of the dielectric member 14, the area of ​​the contact surface between the lower surface of the conductive member 17 and the upper surface of the dielectric member 14 gradually increases. As the area of ​​the contact surface between the lower surface of the conductive member 17 and the upper surface of the dielectric member 14 increases, the capacitance of the capacitor formed by the first land 11 and the conductive member 17 increases. The pressure-sensitive sensor 1 outputs, from the first electrode 102 and the second electrode 104, an electrical signal that indicates the capacitance of the capacitor that changes when the sealing sheet 19 is pressed down.

[0038] (Manufacturing method of pressure-sensitive sensor according to the first embodiment) Figure 3 is a diagram showing a manufacturing method of the pressure-sensitive sensor 1, where Figure 3(a) shows the first step, Figure 3(b) shows the second step, Figure 3(c) shows the third step, and Figure 3(d) shows the fourth step.

[0039] First, in the first step, an aggregate lower frame member 23 having a shape in which a plurality of lower frame members are connected via an aggregate adhesive sheet 22 having a shape in which a plurality of adhesive sheets are connected is placed on an aggregate substrate 21 having a shape in which a plurality of substrates are connected. The aggregate substrate 21 is a single plate material having a shape in which a total of six substrates 10 are connected together in a 2 x 3 arrangement, and first lands 11 and second lands 12 formed by pattern etching are disposed on the upper surface of each substrate 10. The aggregate adhesive sheet 22 is an adhesive sheet with openings in portions corresponding to the first lands and second lands of each substrate 10. The aggregate lower frame member 23 is placed on top of the aggregate adhesive sheet 22. The aggregate lower frame member 23 is a frame member having a shape in which a plurality of lower frame members 13 are connected together in the same arrangement as the arrangement of each substrate 10 on the aggregate substrate 21. A total of six boxes 24 in a 2 x 3 arrangement are formed by arranging the aggregate substrate 21 and the aggregate lower frame member 23. Each box 24 corresponds to a housing portion 131 that surrounds a first land 11 and houses a second land 12 , a dielectric member 14 , a spacer 15 and a conductive member 17 .

[0040] Next, in the second step, the dielectric members 14, spacers 15, connecting members 16, and conductive members 17 are respectively arranged in each box 24 formed by the assembly substrate 21 and the assembly lower frame member 23. The dielectric members 14 are arranged on the first lands 11, and the spacers 15 are arranged on the dielectric member 14 via an adhesive member. The connecting members 16 are inserted into the through holes 132. When the connecting members 16 are, for example, conductive thermosetting resin paste or solder paste, the paste is injected into the through holes 132 using a dispenser. The conductive members 17 are arranged so as to fit into the notched guides 133.

[0041] Next, in the third step, an aggregate upper frame member 25 having a shape in which a plurality of upper frame members are connected together is arranged, and further an aggregate sealing sheet 26 having a shape in which a plurality of sealing sheets are connected together is arranged via an adhesive member, thereby forming an aggregate pressure-sensitive sensor 27 in which the pressure-sensitive sensors 1 are connected together. The aggregate pressure-sensitive sensor 27 is subjected to a heat treatment to thermally harden the adhesive member or adhesive sheet and to melt the conductive thermosetting resin paste and solder paste used in the connection member 16.

[0042] Then, in the fourth step, the collective substrate is cut into the collective pressure-sensitive sensor 27 as shown by the broken lines in Fig. 3(d), forming a total of six pressure-sensitive sensors 1 (2 x 3).

[0043] (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, so the stress generated when the sealing sheet 19 is pressed can be smaller than the stress generated in a sealing sheet of the same thickness made of polyimide resin. Because the stress generated in the sealing sheet 19 is smaller, the pressure-sensitive sensor 1 can have higher detection sensitivity than a pressure-sensitive sensor having a sealing sheet of the same thickness made of polyimide resin.

[0044] (Modification 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 the detection sensitivity of the pressure-sensitive sensor according to the embodiment may be improved in other ways. In the pressure-sensitive sensor according to the embodiment, the detection sensitivity of the pressure-sensitive sensor may be improved by making at least one of the conductive member, the outer frame member, and the sealing sheet a displacement adjustment member that adjusts the displacement of the conductive member pressed down via the sealing sheet when the sealing sheet is pressed down from above.

[0045] For example, in the pressure-sensitive sensor according to the embodiment, the length from one end to the other end of the sealing sheet may be longer than the length from one end of the outer frame member to which 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. The sealing sheet functions as a displacement adjustment member that adjusts the displacement of the conductive member by making its length longer than the length of the outer frame member.

[0046] Fig. 4(a) is a cross-sectional view of a pressure-sensitive sensor according to a first modified example, and Fig. 4(b) is a cross-sectional view of a pressure-sensitive sensor according to a second modified example. The cross-sectional views shown in Fig. 4(a) and 4(b) correspond to the cross-sectional view taken along line A-A' shown in Fig. 1(a).

[0047] The pressure sensor 2 differs from the pressure 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 sensor 2 other than the sealing sheet 31 are the same as the configurations and functions of the components of the pressure sensor 1 that are assigned the same reference numerals, and therefore detailed explanations thereof will be omitted here.

[0048] 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 having a rectangular planar shape made of polyimide resin. The sealing sheet 31 may be made of a synthetic resin material having a lower tensile strength than polyimide resin and thermal properties equivalent to those of polyimide resin, or may be made 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, lower frame member 13, and upper frame member 18, and so that the outer edge coincides with the outer edge of the upper frame member 18.

[0049] The sealing sheet 31 is positioned 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 coincides with the outer edge of the upper frame member 18, so that the central portion 311 is recessed and positioned close to the upper surface of the conductive member 17.

[0050] 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 description thereof will be omitted here.

[0051] The pressure-sensitive 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, and therefore can suppress the stress that occurs when pressed down. The pressure-sensitive sensor 2 can improve its detection sensitivity by suppressing the stress that occurs in the sealing sheet 31 when pressed down.

[0052] The pressure sensor 3 differs from the pressure 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 sensor 3 other than the sealing sheet 33 are the same as the configurations and functions of the components of the pressure sensor 2 that are assigned the same reference numerals, and therefore detailed description thereof will be omitted here.

[0053] The sealing sheet 33 is formed of polyimide resin and has a central portion 331, a connection portion 332, and an outer peripheral portion 333. The central portion 331 has a rectangular planar shape and is disposed so as to be spaced further from the conductive member 17 than the outer peripheral portion 333 by the connection portion 332. The connection portion 332 is thinner than the thicknesses of the central portion 331 and the outer peripheral portion 333. The connection portion 332 extends to the outer edge of the central portion 331, inclining from the inner edge of the outer peripheral portion 333 to be positioned inward as it moves away from the outer peripheral portion 333, and is disposed so as to connect the outer edge of the central portion 331 to the inner edge of the outer peripheral portion 333. The outer peripheral portion 333 has a frame-like planar shape, and its outer edge is bonded to the upper surface of the upper frame member 18. The thickness of the outer peripheral portion 333 is the same as the thickness of the central portion 331.

[0054] In the manufacturing method of the pressure-sensitive sensor 3, reflow is performed before arranging an aggregate sealing sheet including a plurality of sealing sheets 33. After reflow, the aggregate sealing sheet including a plurality of sealing sheets 33 is adhered to the upper surface of the aggregate upper frame member 25. By adhering the aggregate sealing sheet after reflow, the structure of the sealing sheet 33 with the bulged central portion 331 is prevented from being deformed by reflow.

[0055] The pressure-sensitive sensor 3 has the connection portion 332 where the sealing sheet 33 is thin, and therefore can suppress the stress that occurs when the sealing sheet 33 is pressed down. The pressure-sensitive sensor 3 can improve the detection sensitivity by suppressing the stress that occurs in the sealing sheet 33 when the sealing sheet 33 is pressed down.

[0056] Furthermore, in the pressure-sensitive sensor 3, the sealing sheet 33 bends when pressed down, thereby dispersing the stress generated in the sealing sheet 33, reducing the risk of peeling of the adhesive portion bonding the upper frame member 18 and the sealing sheet 33, and reducing the risk of damage to the sealing sheet 33. Meanwhile, in the pressure-sensitive sensor 3, the sealing sheet 33 seals the storage section, so that air does not flow into the storage section from the outside, and dustproofness and waterproofness are maintained.

[0057] In the pressure-sensitive sensor 3, the connection portion between the central portion 331 and the connection portion 332 and the connection portion between the outer peripheral portion 333 and the connection portion 332 are formed to be angular, but in the pressure-sensitive sensor according to the embodiment, the connection portions between the central portion, the connection portion, and the outer peripheral portion may be arc-shaped. Also, the central portion 331 may be recessed by the weight of the sealing sheet 33, so that a portion of the central portion 331 is close to the upper surface of the conductive member 17. Furthermore, the outer peripheral portion 33 may be close to the upper surface of the conductive member 17, similar to the central portion 331.

[0058] (Configuration and Function of Pressure-Sensitive Sensor of Second Embodiment) FIG. 5 is an exploded perspective view of a pressure-sensitive sensor according to a second embodiment.

[0059] The pressure sensor 4 differs from the pressure sensor 1 in that it has a spacer 45 instead of the spacer 15. The configurations and functions of the components of the pressure sensor 4 other than the spacer 45 are the same as those of the components of the pressure sensor 1 with the same reference numerals, and therefore detailed descriptions thereof 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. The opening 46 is a portion where the center of one side of the spacer 45 is missing. The configurations and functions of the spacer 45 other than the formation of the opening 46 are the same as those of the spacer 15, and therefore detailed descriptions thereof will be omitted here. Furthermore, the manufacturing method of the pressure sensor 4 is the same as the manufacturing method of the pressure sensor 1, and therefore detailed descriptions thereof will be omitted here. In this embodiment, the opening is located in the center of one side of the spacer 45, but it may be located elsewhere.

[0060] (Action and effect 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 arranged below the spacer 15 and the conductive member 17 arranged above the spacer 15 is sealed by the dielectric member 14, the spacer 15, and the conductive member 17. In the pressure-sensitive 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 pressed down via the sealing sheet 19 takes time to return to the position it was in before it was pressed down after it is no longer pressed down.

[0061] On the other hand, in the pressure-sensitive sensor 4, the spacer 45 has an opening 46 formed therein, and therefore, the air flows in from the outside through the opening 46 to the area surrounded by the spacer 45, and the air also flows out to the outside through the opening 46. In the pressure-sensitive sensor 4, the air flows in and out of the area surrounded by the spacer 45 through the opening 46, and therefore, the time it takes for the conductive member 17, which is pressed down through the sealing sheet 19, to return to its original position after it is no longer pressed is shorter than that of the pressure-sensitive sensor 1.

[0062] (Modification 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, which is a modification of the pressure-sensitive sensor according to the second embodiment.

[0063] The pressure sensor 5 differs from the pressure sensor 4 in that it has a spacer 55 instead of the spacer 45. The configurations and functions of the components of the pressure sensor 5 other than the spacer 55 are the same as those of the pressure sensor 4 with the same reference numerals, and therefore a detailed description thereof will be omitted here. The spacer 55 differs from the spacer 45 in that an opening 56 is formed on one side of the frame instead of the opening 46. The configurations and functions of the spacer 55 other than the formation of the opening 56 are the same as those of the spacer 45, and therefore a detailed description thereof will be omitted here. Furthermore, the manufacturing method of the pressure sensor 5 is the same as the manufacturing method of the pressure sensor 1, and therefore a detailed description thereof will be omitted here.

[0064] The opening 46 formed in the spacer 45 is formed by cutting one side of the spacer 45, but the opening 56 is a recess formed by recessing the center of one side of the spacer 55 facing the dielectric member 14 without cutting the side of the spacer 55. The opening may be formed by recessing the center of one side of the spacer 55 facing the conductive member 17, but by recessing the center of one side of the spacer 55 facing the dielectric member 14, the opening 56 is formed on the surface of the spacer 55 facing the dielectric member 14 and the surface facing the conductive member 17 is flat, so that the conductive member 17 is not scraped off by the corners of the opening 56 due to repeated pressing. Furthermore, two or more openings may be formed, and they may be formed on both the surface of the spacer facing the dielectric member 14 and the surface facing the conductive member 17.

[0065] FIG. 7 is an exploded perspective view of a pressure-sensitive sensor according to a fourth modified example, which is a modified example of the pressure-sensitive sensor according to the second embodiment.

[0066] The pressure sensor 6 differs from the pressure 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 sensor 6 other than the first spacer 65a and the second spacer 65b are the same as those of the pressure sensor 4 with the same reference numerals, and therefore detailed description thereof will be omitted here.

[0067] The first spacer 65a has a frame-like shape and is disposed between the conductive member 17 and the second spacer 65b so that the upper surface faces the lower surface of the conductive member 17. The first spacer 65a does not have any openings that allow air to flow in and out of the area surrounded by the first spacer 65a and the second spacer 65b.

[0068] Similar to the spacer 45, the second spacer 65b has an opening 66 formed on one side of its frame shape, and is disposed between the dielectric member 14 and the first spacer 65a so as to overlap the first spacer 65a. The outer edge of the second spacer 65b coincides with the outer edge of the first spacer 65a, and the inner edge of the second spacer 65b protrudes inward beyond the inner edge of the first spacer 65a. Although the outer edge of the second spacer 65b coincides with the outer edge of the first spacer 65a in this embodiment, the outer edges do not have to coincide.

[0069] Because the inner edge of the second spacer 65b protrudes inward more than the inner edge of the first spacer 65a, the inner edge of the first spacer 65a contacts the upper surface of the second spacer 65b without contacting the dielectric member 14. Since the second spacer 65b is disposed between the first spacer 65a and the dielectric member 14, even if shavings are generated when the conductive member 17 is scraped off between the inner edge of the first spacer 65a and the dielectric member 14, the thickness of the second spacer 65b reduces the risk of a short circuit between the conductive member 17 and the dielectric member 14 via the shavings, resulting in malfunction. The openings 66 may be formed in both the first spacer 65a and the second spacer 65b. When the openings 66 are formed in both the first spacer 65a and the second spacer 65b, the openings 66 of the first spacer 65a and the second spacer 65b are preferably arranged so as not to overlap each other when the first spacer 65a and the second spacer 65b are viewed in plan. 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 risk of a short circuit between the dielectric member 14 and the conductive member 17 due to shavings generated at the openings is reduced, resulting in a malfunction. Furthermore, the first spacer 65a and the second spacer 65b may be arranged so that the openings 66 formed in the first spacer 65a and the second spacer 65b partially overlap when viewed in plan. The overlapping width of the openings 66 formed in the first spacer 65a and the second spacer 65b is preferably wider than the sum of the accumulation width of shavings scraped off at the opening 66 of the first spacer 65a and the accumulation width of shavings scraped off at the opening 66 of the second spacer 65b. By making the overlapping width of the openings 66 wider than the sum of the accumulation widths of the shavings scraped off at the openings 66 of the first spacer 65a and the second spacer 65b, the risk of the shavings scraped off coming into contact with both openings 66, causing a short circuit between the dielectric member 14 and the conductive member 17 and resulting in malfunction is reduced.

[0070] The first spacer 65a is disposed between the conductive member 17 and the second spacer 65b, but may be disposed 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 so that its inner edge protrudes inward beyond the inner edge of the second spacer 65b. Since the first spacer 65a, which does not have an opening on one side of the frame shape, is disposed between the second spacer 65b and the dielectric member 14, the dielectric member 14 is not exposed at the inner edge and opening 66 of the second spacer 65b, and there is little risk of a short circuit between the dielectric member 14 and the conductive member 17 due to shavings scraped off by the second spacer 65b, causing malfunction.

[0071] In the pressure-sensitive sensors 4 to 6, the spacers 45, 55, and 65b are provided with the openings 46, 56, and 66, respectively, so that the atmosphere can flow in and out of the area surrounded by the spacers 45, 55, 65a, and 65b. However, in the pressure-sensitive sensor according to the embodiment, a spacer 15 without openings may be used, and openings that allow the atmosphere to flow in and out of the area surrounded by the spacer 15 may be formed between the dielectric member 14 and the conductive member 17 and the spacer 15.

[0072] In the pressure-sensitive sensor according to the embodiment, the adhesive member that adheres the spacer 15 to the dielectric member 14 may not be disposed over the entire lower surface of the spacer 15, but may be disposed only on a portion of the lower surface of the spacer 15, thereby forming an opening through which air can flow in and out in the area surrounded by the spacer 15. Furthermore, in the pressure-sensitive sensor according to the embodiment, an opening through which air can flow in and out may be formed in the area surrounded by the spacer 15 by peeling off a portion of the adhesive member that is disposed over the entire lower surface of the spacer 15.

[0073] (Configuration and Function of Pressure-Sensing Sensor of Third Embodiment) Fig. 8 is a cross-sectional view of a pressure-sensitive sensor according to a third embodiment. The cross-sectional view shown in Fig. 8 corresponds to the cross-sectional view taken along line AA' shown in Fig. 1(a).

[0074] The pressure sensor 7 differs from the pressure sensor 1 in that it has a spacer 75 instead of the spacer 15. The configurations and functions of the components of the pressure sensor 7 other than the spacer 75 are the same as the configurations and functions of the components of the pressure sensor 1 that are assigned the same reference numerals, so detailed explanations will be omitted here. In addition, the manufacturing method of the pressure sensor 7 is the same as the manufacturing method of the pressure sensor 1, so detailed explanations will be omitted here.

[0075] The spacer 75 has a hard layer 751 and a soft layer 752. The hard layer 751 is an insulating member having a frame-like planar shape made of synthetic resin such as polyimide resin, and is disposed on the dielectric member 14.

[0076] The soft layer 752 is an adhesive layer that is disposed so as to coincide with the outer edge of the hard layer 751 and adheres the hard layer 751 to the conductive member 17. In one example, the thickness of the hard layer 751 is 25 μm, and the thickness of the soft layer 752 is 10 μm.

[0077] The soft layer 752 is an adhesive insulating member having a frame-like planar shape and made of a synthetic resin such as an acrylic resin that has a lower hardness than the polyimide resin that forms the hard layer 751. The hardness of the hard layer 751 and the soft layer 752 is lower than the hardness of the dielectric member 14. The hardness of the components of the pressure 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 or the like measured in accordance with ASTM D785.

[0078] (Effects of the pressure-sensitive sensor according to the third embodiment) In the pressure-sensitive sensor 7, the soft layer 752, which has a lower hardness than the hard layer 751, contacts the conductive member 17, so there is a low risk that shavings generated when the conductive member 17 is scraped off will accumulate on the dielectric member 14, causing a short circuit between the conductive member 17 and the dielectric member 14 and resulting in malfunction. In the pressure-sensitive sensor 4, when the conductive member 17 is pressed down and sinks into the area surrounded by the spacer 45, it comes into contact with the opening 46 of the spacer 45. In the pressure-sensitive sensor 4, there is a risk of shavings being generated when the conductive member 17 repeatedly comes into contact with the opening 46 of the spacer 45 over a long period of time. However, in the pressure-sensitive sensor 7, the soft layer 752, which has a lower hardness than the hard layer 751, contacts the conductive member 17, so the generation of shavings is suppressed. Furthermore, 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 can ensure the necessary distance between the conductive member 17 and the dielectric member 14. Furthermore, the soft layer 752 does not come into contact with the dielectric member 14, and therefore the soft layer 752 can be prevented from being scraped off by the dielectric member 14.

[0079] FIG. 9A is a cross-sectional view showing the pressure-sensitive sensor 1 according to the first embodiment in a pressed state, and FIG. 9B is a cross-sectional view showing the pressure-sensitive sensor 7 in a pressed state.

[0080] In the pressure-sensitive sensor 1, each time the presser 200 presses down on the conductive member 17 via the sealing sheet 19, the upper portion 351 of the inner wall of the spacer 15 that contacts the conductive member 17 scrapes off the contact portion with the conductive member 17, and there is a risk that shavings 352 will be generated due to repeated pressing of the conductive member 17. If the pressure-sensitive sensor 1 is repeatedly pressed down approximately one million times, the shavings 352 will accumulate on the surface of the dielectric member 14, and there is a risk that a short circuit will occur between the conductive member 17 and the dielectric member 14, resulting in malfunction.

[0081] On the other hand, in the pressure-sensitive sensor 7 according to the embodiment, the soft layer 752, which has low hardness and is adhesive, bends together with the conductive member 17 in response to the presser 200 pressing down on the conductive member 17 via the sealing sheet 19, so that the conductive member 17 is less likely to be scraped off by the spacer 75. In the pressure-sensitive sensor 7, the conductive member 17 is less likely to be scraped off by the spacer 75 due to repeated pressing, so that conductive shavings are less likely to accumulate on the dielectric member 14, causing a short circuit between the conductive member 17 and the dielectric member 14 and resulting in malfunction, and the sensor can have a longer lifespan.

[0082] 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, the dielectric member 14 and the hard layer 751, which have relatively high hardness, are arranged adjacent to each other, which increases durability and enables a longer lifespan.

[0083] (Variant example of pressure-sensitive sensor according to the third embodiment) In the pressure-sensitive sensor 7, the soft layer 752 is an adhesive layer that bonds the hard layer 751 and the conductive member 17, but in the pressure-sensitive sensor according to the embodiment, the soft layer does not have to be an adhesive layer as long as it has a lower hardness than the resin that forms the hard layer 751.

[0084] Furthermore, in the pressure-sensitive sensor 7, the hard layer 751 is formed of polyimide resin, but in the pressure-sensitive sensor according to the embodiment, the hard layer may be formed of a resin other than polyimide resin as long as it is harder than the soft layer 752.

[0085] Furthermore, 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 may be thicker than or the same as the thickness of the hard layer. 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 is less likely to scrape the conductive member, and the generation of conductive shavings can be suppressed.

Claims

1. 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; 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 disposed on the substrate and forming, together with the substrate, an accommodation portion that accommodates the first lands, the second lands, the dielectric member, the spacer, and the conductive member; a sealing sheet fixed on the outer frame member and sealing the storage portion; A first electrode electrically connected to the first land; a second electrode electrically connected to the second land, A pressure-sensitive sensor characterized in that the sealing sheet has a bulge or depression in the center so that the stress generated in the sealing sheet when pressed is reduced, and is positioned so that its outer edge coincides with the outer edge of the outer frame member.

2. The encapsulating sheet is An outer periphery fixed on the outer frame member; a central portion surrounded by the outer periphery and disposed farther away from the conductive member than the outer periphery; a connecting portion extending from an inner edge of the outer periphery portion toward an outer edge of the central portion and connecting the outer periphery portion and the central portion, The pressure-sensitive sensor according to claim 1 , wherein the connection portion has a thickness smaller than that of the central portion and that of the outer circumferential portion.

3. The encapsulating sheet is An outer periphery fixed on the outer frame member; a central portion surrounded by the outer periphery and disposed farther away from the conductive member than the outer periphery, The pressure-sensitive sensor according to claim 1 , wherein the central portion is disposed closer to the dielectric body than the outer circumferential portion.

4. 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; 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 disposed on the substrate and forming, together with the substrate, an accommodation portion that accommodates the first lands, the second lands, the dielectric member, the spacer, and the conductive member; a sealing sheet fixed on the outer frame member and sealing the storage portion; A first electrode electrically connected to the first land; a second electrode electrically connected to the second land, The spacer is a first spacer that is a soft layer having a frame shape and that is disposed between the dielectric member and the conductive member; a second spacer that is a hard layer formed of a material having a hardness higher than that of the soft layer and that is disposed between the dielectric member and the first spacer; A pressure-sensitive sensor, characterized in that the hardness of the first spacer is lower than the hardness of the conductive member.

5. The pressure-sensitive sensor according to claim 4 , wherein an opening through which air can flow in and out is formed in an area surrounded by the spacer.

6. (delete)

7. (delete)

8. (delete)

9. the second spacer is disposed between the dielectric member and the first spacer; The pressure-sensitive sensor according to claim 5 , wherein an inner edge of the second spacer protrudes inward beyond an inner edge of the first spacer.

10. The pressure-sensitive sensor according to claim 5 , wherein the second spacer has a frame shape with a portion missing.

11. each of the first spacer and the second spacer has a frame shape with a portion missing, The pressure-sensitive sensor according to claim 5 , wherein the first spacer and the second spacer are arranged such that the missing portions do not overlap with each other when the first spacer and the second spacer are viewed in a plan view.

12. each of the first spacer and the second spacer has a frame shape with a portion missing, The pressure-sensitive sensor according to claim 5 , wherein the first spacer and the second spacer are arranged such that a part of the missing portion overlaps when the first spacer and the second spacer are viewed in a plan view.