pressure sensor

Abstract

The object of this invention is to provide a pressure sensor capable of improving output characteristics. The pressure sensor 1A includes: a substrate 11, a resistor 14 disposed on an upper surface 111 of the substrate 11, a wiring pattern 12 disposed on the upper surface 111 and connected to the resistor 14, comb patterns 15A to 15I disposed on the upper surface 111 and each independently connected to the resistor 14, a wiring pattern 16 disposed on the upper surface 111, a substrate 21, a connector 22 disposed on a lower surface of the substrate 21, a spacer 30 between the substrate 11 and the substrate 21, a spacer 40 disposed on the lower surface 112 of the substrate 11, the upper surface 111 having a highest portion 114 that is higher than other portions of the upper surface 111 by means of the spacer 40, and an inclined surface 115 extending from the highest portion 114. In a top view, the comb patterns 15A to 15I include comb patterns 15A to 15I that overlap with the inclined surface 115.

Description

[Technical Field]

[0001] The present invention relates to a pressure sensor whose resistance value changes in response to an applied load. [Previous Technology]

[0002] A known pressure sensor includes: a plurality of comb patterns arranged in a concentric circle shape; a resistor connected to the comb patterns at equal intervals; a first wiring pattern connected to the resistor; a second wiring pattern having a front end disposed at the center of the concentric circles; a first substrate provided with the comb patterns, the first wiring pattern, and the second wiring pattern; a connector facing the concentric circles; a second substrate provided with the connector; and a spacer having an opening and located between the first substrate and the second substrate (e.g., see Patent Document 1). In this pressure sensor, as the load applied to the second substrate increases, the comb patterns sequentially contact the connector from the inside to the outside, and the resistance value between the first wiring pattern and the second wiring pattern changes in stages. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2022 / 130754 [Summary of the Invention]

[0004] [Problem to be solved by the invention] When the pressure sensor described above is disposed on the support body through the bonding material, air bubbles remain between the first substrate and the support surface of the support body. These air bubbles cause the upper surface of the first substrate to deform into a convex shape. This convexity causes the connector to come into contact with multiple comb patterns simultaneously, resulting in a drastic change in resistance value and degrading the output characteristics of the pressure sensor.

[0005] The problem this invention aims to solve is to provide a pressure sensor capable of improving output characteristics. [Means for solving the problem]

[0006] [1] Embodiment 1 of the present invention is a pressure sensor, comprising: a first substrate having a first main surface and a second main surface; a resistor disposed on the first main surface; a first wiring pattern disposed on the first main surface and connected to the resistor; a plurality of comb patterns disposed on the first main surface and each independently connected to the resistor; a pressing device comprising: a pressing portion facing the comb patterns and accessible to the first main surface, and a connecting body held in the pressing portion and electrically connected to the comb patterns by pressing by the pressing portion; a second wiring pattern disposed on the first main surface and electrically connected to the connecting body by pressing by the pressing portion, or included in the pressing device and connected to the connecting body; and a first spacer disposed on the second main surface. In a top view, the resistor is positioned at a position that does not overlap with the connecting body. The first main surface includes: a highest portion that is higher than other portions of the first main surface by means of the first spacer; and an inclined surface extending from the highest portion. In a top-view perspective, the aforementioned plurality of comb tooth patterns include a plurality of first comb tooth patterns overlapping the aforementioned inclined surface. The resistance value changes between the aforementioned first wiring pattern and the aforementioned second wiring pattern corresponding to the load applied to the aforementioned pressing portion.

[0007] [2] The second form of the present invention may be that, in the pressure sensor of the first form 1, the first spacer overlaps with the connecting body in the top view. The opposing region of the first main surface opposite to the connecting body includes the highest part and the inclined surface.

[0008] [3] The present invention may be in the pressure sensor of the present invention, in which the aforementioned second wiring pattern is disposed on the aforementioned first main surface. In a top view, the aforementioned highest part overlaps with the aforementioned second wiring pattern.

[0009] [4] The present invention, in the pressure sensor of the present invention, may have the aforementioned second wiring pattern disposed on the aforementioned first main surface. The aforementioned first wiring pattern is connected to the first end of the aforementioned resistor. The aforementioned plurality of comb patterns are spaced apart from each other and connected between the aforementioned first end and the second end of the aforementioned resistor. The aforementioned plurality of comb patterns includes a second comb pattern connected to the aforementioned second end of the aforementioned resistor. In a top view, the aforementioned highest portion is closer to the aforementioned second wiring pattern than the aforementioned second comb pattern.

[0010] [5] The present invention may be in the pressure sensor of the present invention 3 or 4, wherein the aforementioned pressing device includes: a second substrate on which the aforementioned connecting body is disposed; and a second spacer between the aforementioned first substrate and the aforementioned second substrate. The aforementioned second spacer has an opening that aligns the aforementioned connecting body with the aforementioned second wiring pattern and the aforementioned comb pattern.

[0011] [6] Embodiment 6 of the present invention may be, in the pressure sensor of embodiment 1 or 2, the aforementioned second wiring pattern is included in the aforementioned pressing device and connected to the aforementioned connector. The aforementioned first wiring pattern is connected to the first end of the aforementioned resistor. The aforementioned plurality of comb patterns are spaced apart from each other and connected between the aforementioned first end and the second end of the aforementioned resistor. The aforementioned plurality of comb patterns includes a second comb pattern connected to the aforementioned second end of the aforementioned resistor. In a top view, the aforementioned highest portion overlaps with the aforementioned second comb pattern.

[0012] [7] Embodiment 7 of the present invention may be, in the pressure sensor of embodiment 1 or 2, the aforementioned second wiring pattern is included in the aforementioned pressing device and connected to the aforementioned connector. The aforementioned first wiring pattern is connected to the first end of the aforementioned resistor. The aforementioned plurality of comb patterns are spaced apart from each other and connected between the aforementioned first end and the second end of the aforementioned resistor. The aforementioned plurality of comb patterns includes a second comb pattern connected to the aforementioned second end of the aforementioned resistor. In a top view, the aforementioned highest portion is closer to the aforementioned second comb pattern than the other aforementioned comb patterns.

[0013] [8] The present invention may be in the pressure sensor of the present invention 6 or 7, wherein the aforementioned pressing device includes: a second substrate having the aforementioned connector and the aforementioned second wiring pattern disposed thereon; and a second spacer between the aforementioned first substrate and the aforementioned second substrate. The aforementioned second spacer has an opening that causes the aforementioned connector to face the aforementioned comb pattern.

[0014] [9] Embodiment 9 of the present invention may be, in any of Embodiments 1 to 8, in a pressure sensor, the aforementioned first wiring pattern is connected to the first end of the aforementioned resistor. The aforementioned plurality of comb patterns are spaced apart from each other and connected between the aforementioned first end and the second end of the aforementioned resistor. The aforementioned plurality of comb patterns includes a second comb pattern connected to the aforementioned second end of the aforementioned resistor. In the region opposite to the aforementioned first main surface opposite to the aforementioned connector, the width of the aforementioned second comb pattern is wider than the width of the other aforementioned comb patterns.

[0015]

[10] The present invention may be a pressure sensor in any of the embodiments 1 to 9, wherein in the opposing region of the first main surface opposite to the aforementioned connecting body, the aforementioned plurality of comb patterns are spaced apart from each other and arranged side by side.

[0016]

[11] The present invention, in the pressure sensor of the present invention, may have the first wiring pattern connected to the first end of the resistor. The plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor. The plurality of comb patterns are disposed on the first main surface such that the closer the connection position of the comb pattern to the resistor is to the second end, the closer the comb pattern is to the highest point.

[0017]

[12] The present invention may be that, in the pressure sensor of the present invention 10 or 11, in the top view, the aforementioned plurality of comb patterns are arranged in a concentric circle shape with the aforementioned highest part as the center.

[0018]

[13] The present invention may be a pressure sensor in any of the embodiments 1 to 12, wherein the plurality of comb patterns includes a third comb pattern connected to the first end of the aforementioned resistive element. The aforementioned first wiring pattern is connected to the aforementioned third comb pattern.

[0019]

[14] The present invention may be in the pressure sensor of any of the embodiments 1 to 13, wherein the first spacer is disposed between the support body and the second main surface, and the support body has a support surface that supports the pressure sensor.

[0020]

[15] Embodiment 15 of the present invention may be that, in the pressure sensor of any of Embodiments 1 to 14, the material constituting the aforementioned resistive element has a higher resistivity than the resistivity of the material constituting the aforementioned first wiring pattern, the resistivity of the material constituting the aforementioned first comb pattern, the resistivity of the material constituting the aforementioned connector, and the resistivity of the material constituting the aforementioned second wiring pattern. [Effects of the Invention]

[0021] In this invention, a first spacer is disposed on the second main surface of a first substrate. The first main surface of the first substrate has a highest portion that is higher than other parts of the first main surface by means of the first spacer, and an inclined surface extending from the highest portion. In a top view, a plurality of first comb tooth patterns overlap with the inclined surface. Therefore, the plurality of first comb tooth patterns can sequentially contact the connector, thereby improving the output characteristics of the pressure sensor.

Implementation Method

[0023] In the following, embodiments of the present invention will be described based on the drawings.

[0024] <<First Embodiment>> Figure 1 is a top view showing the pressure sensor 1A in the first embodiment of the present invention, Figure 2 is a cross-sectional view along line II-II in Figure 1, Figure 3 is a top view showing the lower membrane substrate 10 in this embodiment, and Figure 4 is a bottom view showing the spacer 30 and the upper membrane substrate 20 in this embodiment.

[0025] The pressure sensor 1A in this embodiment is a sensor whose resistance value changes according to the applied load. As shown in Figures 1 to 4, this pressure sensor 1A includes a lower membrane substrate 10, an upper membrane substrate 20, a spacer 30, and a spacer 40. The upper membrane substrate 20 and the spacer 30 correspond to an example of a "pressing device" in this embodiment, the spacer 40 corresponds to an example of a "first spacer" in this embodiment, and the spacer 30 corresponds to an example of a "second spacer" in this embodiment.

[0026] As shown in Figure 3, the lower film substrate 10 is a circuit board including a substrate 11, a wiring pattern 12, a resistor 14, comb patterns 15A to 15I, and a wiring pattern 16. The substrate 11 corresponds to an example of the "first substrate" in the present invention, the wiring pattern 12 corresponds to an example of the "first wiring pattern" in the present invention, the wiring pattern 16 corresponds to an example of the "second wiring pattern" in the present invention, and the comb patterns 15A to 15I correspond to an example of the "comb pattern" in the present invention.

[0027] The substrate 11 is a thin film-like member made of a material that is flexible and electrically insulating. Examples of materials constituting this substrate 11 include resin materials, and more specifically, examples include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

[0028] The wiring pattern 12 is formed by printing conductive adhesive onto the surface 111 of the substrate 11 and then curing (hardening). The conductive adhesive is composed of conductive particles and adhesive resin mixed with water or solvent and various additives. The conductive adhesive constituting this wiring pattern 12 is a low-resistance conductive adhesive with a relatively low resistance value. Furthermore, the method of forming the wiring pattern 12 is not particularly limited to the above. For example, instead of conductive adhesive, the wiring pattern 12 can also be formed by etching metal foil.

[0029] Specific examples of conductive particles include silver, copper, nickel, tin, bismuth, zinc, indium, palladium, and their alloys. Specific examples of adhesive resins include acrylic resins, polyester resins, epoxy resins, vinyl resins, polyurethane resins, phenolic resins, polyimide resins, silicone resins, and fluororesins. Furthermore, examples of solvents included in the conductive adhesive include α-terpineol, butyl carbitol acetate, butyl carbitol, n-decanol, butyl cellosolve, diethylene glycol ethyl ether acetate, and tetradecane.

[0030] Although not particularly limited, in this embodiment, silver paste, in which silver is the main component of the conductive particles, or copper paste, in which copper is the main component of the conductive particles, is used as the low-resistance conductive adhesive. Furthermore, metal salts can also be used as the conductive particles contained in the conductive adhesive. Examples of metal salts include salts of the aforementioned metals. In addition, the adhesive resin can be omitted from the aforementioned conductive adhesive. Furthermore, conductive ink can also be used instead of the aforementioned conductive adhesive.

[0031] The coating method for the conductive adhesive is not particularly limited, and either a contact coating method or a non-contact coating method can be used. Specific examples of contact coating methods include screen printing, gravure printing, offset printing, gravure offset printing, and flexographic printing. On the other hand, specific examples of non-contact coating methods include inkjet printing, inkjet coating, dispensing coating, and jet dispensing. Furthermore, the heat source for curing the conductive adhesive is not particularly limited, and examples include electric ovens, infrared furnaces, far-infrared furnaces (IR), near-infrared furnaces (NIR), laser irradiation devices, etc., or combinations thereof.

[0032] In this embodiment, the wiring pattern 12 extends linearly along the X direction in the figure. The end 121 of this wiring pattern 12 is covered by the resistor 14, and this wiring pattern 12 is connected to the resistor 14. Furthermore, although the planar shape of the wiring pattern 12 is linear, it is not limited to a straight line as described above.

[0033] The resistor 14 is disposed along the Y direction in the figure, and one end 141 of the resistor 14 covers the end 121 of the wiring pattern 12. In a top view, the resistor 14 is disposed in the substrate 11 at a position away from the opposing region 113 (described below) in a manner that does not overlap with the connector 22 of the upper film substrate 20.

[0034] This resistor 14 is similar to the wiring pattern 12 described above, and is formed by printing conductive adhesive onto the surface 111 of the substrate 11 and curing (hardening). The conductive adhesive constituting this resistor 14 is a high-resistance conductive adhesive with a relatively higher resistance value compared to the low-resistance conductive adhesive described above. The conductive adhesive constituting this resistor 14 contains conductive particles with a resistivity higher than that of the conductive particles constituting the conductive adhesive of the wiring pattern 12. That is, the resistor 14 is made of a material with a resistivity higher than that of the material constituting the wiring pattern 12, and the resistance value of the resistor 14 is higher than that of the wiring pattern 12, to the point that the resistance value of the wiring pattern 12 is negligible. Specifically, the resistance value of the resistor 14 is more than 10 times the resistance value of the wiring pattern 12, preferably more than 100 times the resistance value of the wiring pattern 12. In addition, the resistivity of the material constituting the resistor 14 is more than 10 times the resistivity of the material constituting the wiring pattern 12, preferably more than 100 times.

[0035] As a specific example of such a high-resistivity conductive adhesive, carbon paste can be cited. As a specific example of conductive particles contained in the conductive adhesive constituting the resistive body 14, carbon-based materials such as graphite, carbon black (furnace black, acetylene black, Ketjen black), carbon nanotubes, and carbon nanofibers can be cited. Furthermore, carbon ink can also be used instead of the aforementioned carbon paste.

[0036] A plurality of comb patterns 15A to 15I (nine in this example) are similar to the wiring pattern 12 described above, and are formed by printing a low-resistance conductive adhesive onto the surface 111 of the substrate 11 and then curing it. That is, each comb pattern 15A to 15I is made of a material having a lower resistivity than the material constituting the resistor 14, and the resistance value of the resistor 14 is higher than the resistance value of the comb patterns 15A to 15I, to the point that the resistance value of each comb pattern 15A to 15I is negligible. Specifically, the resistance value of the resistor 14 is more than 10 times the resistance value of the comb patterns 15A to 15I, preferably more than 100 times the resistance value of the comb patterns 15A to 15I. Furthermore, the resistivity of the material constituting the resistor 14 is more than 10 times the resistivity of the material constituting the comb patterns 15A to 15I, preferably more than 100 times. Furthermore, the method for forming the comb patterns 15A to 15I is not particularly limited to the above. For example, instead of conductive adhesive, the comb patterns 15A to 15I can also be formed by etching metal foil.

[0037] The wiring pattern 16 is similar to the wiring pattern 12 described above, and is formed by printing a low-resistance conductive adhesive onto the surface 111 of the substrate 11 and then curing it. That is, this wiring pattern 16 is constructed using a material with a lower resistivity than the material constituting the resistor 14. The resistance of the resistor 14 is higher than the resistance of this wiring pattern 16, to the point that the resistance of the wiring pattern 16 is negligible. Specifically, the resistance of the resistor 14 is at least 10 times that of the wiring pattern 16, preferably at least 100 times. Furthermore, the resistivity of the material constituting the resistor 14 is at least 10 times that of the material constituting the wiring pattern 16, preferably at least 100 times. Moreover, the method of forming the wiring pattern 16 is not particularly limited to the above. For example, instead of conductive adhesive, the wiring pattern 16 can also be formed by etching a metal foil.

[0038] In this embodiment, each comb pattern 15A to 15I has a straight portion 151 and an arc portion 152. The straight portion 151 of each comb pattern 15A to 15I extends linearly along the X direction in the figure, and a portion of this straight portion 151 is located outside the opposing region 113. In contrast, the arc portion 152 of each comb pattern 15A to 15I is located in the opposing region 113 and is electrically connected to the resistor 14 via the straight portion 151. Here, the opposing region 113 is the circular region of the upper surface 111 of the substrate 11 that faces the connector 22 of the upper film substrate 20 in a top view.

[0039] In this embodiment, the portion of the comb patterns 15A to 15I located within the opposing region 113 functions as a detection unit 155 for detecting the load applied to the pressure sensor 1A, and this detection unit 155 includes an arc portion 152. In contrast, the portion of the comb patterns 15A to 15I located outside the opposing region 113 functions as a lead-out portion 156 that electrically connects the detection unit 155 to the resistor 14, and this lead-out portion 156 includes a portion of a straight line portion 151.

[0040] The straight portions 151 of the comb patterns 15A to 15I are connected between the ends 141 and 142 of the resistor 14, spaced apart from each other in a direction from one end 141 to the other end 142 (Y direction in the figure). In other words, each of the comb patterns 15A to 15I is independently connected to the resistor 14. On the substrate 11, the plurality of comb patterns 15A to 15I are electrically insulated from each other by ensuring the spacing between them, in addition to being electrically connected via the resistor 14. Furthermore, the number of comb patterns is not particularly limited to the above as long as there are a plurality of them. The end 141 on one side of the resistor 14 corresponds to an example of the "first end" in the present invention, and the end 142 on the other side of the resistor 14 corresponds to an example of the "second end" in the present invention.

[0041] The ends of the straight sections 151 of the comb patterns 15A to 15I are covered by resistors 14, and the comb patterns 15A to 15I are connected to resistors 14. Resistors 14 are inserted between the ends of the straight sections 151 of the comb patterns 15A to 15I. In the opposing region 113, the straight section 151 of the outermost comb pattern 15A of the nine comb patterns 15A to 15I is connected to the end 141 on one side of the resistor 14. On the other hand, in the opposing region 113, the straight section 151 of the innermost comb pattern 15I of the nine comb patterns 15A to 15I is connected to the end 142 on the other side of the resistor 14. The straight section 151 of the outermost comb pattern 15A is directly connected to the end 121 of the wiring pattern 12. Resistors 14 are also inserted between the end 121 of this wiring pattern 12 and the end of the straight section 151 of the comb pattern 15B. Furthermore, the outermost comb pattern 15A may not be directly connected to the wiring pattern 12.

[0042] Furthermore, in this embodiment, although the comb patterns 15A to 15I are substantially equally spaced and connected to the resistor 14, it is not particularly limited to this as long as the comb patterns 15A to 15I are spaced apart from each other and connected to the resistor 14. Although not specifically illustrated, for example, in the opposing region, the outerer the position of the comb pattern, the narrower the connection interval between the comb pattern and the resistor.

[0043] The straight portions 151 of the nine comb patterns 15A to 15I extend linearly from the resistor 14 to the opposing region 113 toward the -X side in the figure, spaced apart and extending substantially parallel to each other. The wiring pattern 16, also spaced apart and extending substantially parallel to the straight portions 151 of the comb patterns 15I, has a front end portion 161 at its center CP extending to the center CP of the opposing region 113. Furthermore, although not specifically illustrated, a portion of this wiring pattern 16 may also be covered by the end portion 142 on the other side of the resistor 14.

[0044] The front end portion 161 is formed as an enlarged diameter portion, having a circular shape and a diameter larger than the width of other portions of the wiring pattern 16 (e.g., the portion of the wiring pattern 16 other than the front end portion 161 within the opposing region 113). In this way, the wiring pattern 16 has an enlarged diameter portion 161 at its front end, thereby achieving stability of load detection at the start of pressing. Furthermore, the planar shape of the enlarged diameter portion 161 is not limited to a circle; for example, it can be elliptical, oblong, rectangular, or polygonal. Alternatively, the wiring pattern 16 may not have an enlarged diameter portion at its front end.

[0045] In contrast, in the opposing region 113, the comb patterns 15A to 15I are spaced apart and extend substantially parallel to each other, surrounding the front end portion 161 of the wiring pattern 16. More specifically, in this embodiment, in the opposing region 113, each of the comb patterns 15A to 15I has an arcuate portion 152 extending in an arc shape surrounding the front end portion 161 of the wiring pattern 16. The arcuate portions 152 of these plurality of comb patterns 15A to 15I are arranged in a concentric circle shape with the front end portion 161 of the wiring pattern 16 as the center.

[0046] Furthermore, in this embodiment, although the arcuate portions 152 of the comb tooth patterns 15A to 15I are substantially equally spaced, the arrangement of the arcuate portions 152 is not particularly limited thereto, as long as the spacing between the arcuate portions 152 is ensured. For example, although not specifically illustrated, in opposing regions, the outerer the position of the comb tooth pattern, the narrower the spacing between the arcuate portions of this comb tooth pattern may be.

[0047] Furthermore, in this embodiment, although it is described that the pressing start position (the contact start position of the connector 22 with respect to the lower membrane substrate 10) (specific point) of the pressing member (described below) coincides with the center CP of the opposing region 113, this pressing start position can also be a position other than the center CP of the opposing region 113. As long as it is within the opposing region 113, it can be arbitrarily set. In this case, the comb pattern is arranged in a concentric circle shape with the above-mentioned pressing start position other than the center CP of the opposing region 113 as the center.

[0048] In this embodiment, the arcuate portions 152 of the comb patterns 15A to 15H have the same width w0. On the other hand, in the opposing region 113, the arcuate portion 152 of the innermost comb pattern 15I has a width w1 (w1 > w0) that is wider than the width w0 of the other comb patterns 15A to 15H. Furthermore, it is also possible for all comb patterns 15A to 15I to have the same width of arcuate portions 152.

[0049] Furthermore, the innermost comb pattern 15I and wiring pattern 16 can also be connected via a connecting line. In this way, the output of the pressure sensor 1A in the non-pressed state can be set to the desired value.

[0050] Furthermore, the shape of the detection section of the comb pattern is not particularly limited to the shape described above, as long as it is a shape in which a plurality of comb patterns are arranged at intervals from the inside to the outside in the opposing region. Although not specifically illustrated, for example, in the opposing region 113, the comb patterns 15A to 15I may also have a bent portion instead of the arc portion 152, having a roughly U-shaped shape bent at a right angle.

[0051] Furthermore, in this embodiment, although the comb patterns 15A to 15I extend linearly outside the opposing region 113, the planar shape of the comb patterns outside the opposing region is not particularly limited to this, as long as it is linear. Furthermore, in this embodiment, although the comb patterns 15A to 15I are also substantially parallel outside the opposing region 113, this is not particularly limited; multiple comb patterns may not be substantially parallel outside the opposing region.

[0052] As shown in Figure 4, the upper film substrate 20 includes a substrate 21 and a connector 22. The substrate 21 corresponds to an example of the "second substrate" in the present invention, and the connector 22 corresponds to an example of the "connector" in the present invention.

[0053] The substrate 21 is similar to the substrate 11 described above, and is a thin-film member made of a material that is flexible and electrically insulating. Examples of materials constituting this substrate 21 include resin materials, and more specifically, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are examples. Furthermore, a metal film can also be used as the substrate 21; in this case, the substrate 21 can also function as a connector 22, that is, the substrate 21 can also serve as a connector 22.

[0054] As shown in Figures 1 and 4, the connector 22 has a circular planar shape corresponding to the arcuate portions 152 of the comb patterns 15A to 15I on the lower film substrate 10. Specifically, this connector 22 has a circular shape and a diameter larger than the diameter of the arcuate portion 152 of the outermost comb pattern 15A. In this embodiment, although this connector 22 has a smaller diameter than the opening 31 of the spacer 30, it is not particularly limited to this, and the connector 22 may also have a diameter larger than the inner diameter of the opening 31. This connector 22 is formed on the substrate 21 so that when the lower film substrate 10 and the upper film substrate 20 are laminated via the spacer 30, it faces the arcuate portions 152 of the comb patterns 15A to 15I, and the center of the connector 22 overlaps with the front end portion 161 of the wiring pattern 16.

[0055] This connector 22 is similar to the wiring pattern 12 described above, and is formed by printing low-resistance conductive adhesive onto the lower surface 212 of the substrate 21 and then curing it. That is, this connector 22 is made of a material with a lower resistivity than the material constituting the resistor 14, and the resistance of the resistor 14 is higher than the resistance of this connector 22, to the point that the resistance of the connector 22 is negligible. Specifically, the resistance of the resistor 14 is at least 10 times that of the connector 22, preferably at least 100 times. Furthermore, the resistivity of the material constituting the resistor 14 is at least 10 times that of the material constituting the connector 22, preferably at least 100 times. Moreover, the method of forming the connector 22 is not particularly limited to the above. For example, instead of conductive adhesive, the connector 22 can also be formed by etching a metal foil.

[0056] Furthermore, this connector 22 may also include a protective layer covering the aforementioned layer formed by printing and curing the conductive adhesive of the resistive element. This protective layer is formed by printing and curing a high-resistance conductive adhesive having a higher resistance value than the aforementioned low-resistance conductive adhesive. As a specific example of such a high-resistance conductive adhesive, although not particularly limited, carbon paste may be exemplified.

[0057] The spacer 30 is similar to the substrate 11 and substrate 21 described above, and is a thin film member made of a material that is flexible and electrically insulating. As the material constituting this spacer 30, resin materials may be exemplified, and more specifically, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) may be exemplified.

[0058] This spacer 30 has a circular opening 31 corresponding to the arcuate portion 152 of the comb patterns 15A to 15I of the lower film substrate 10. Specifically, this opening 31 has a circular shape and an inner diameter larger than the diameter of the arcuate portion 152 of the outermost comb pattern 15A. Although not particularly limited, in a top view, the gap between this opening 31 and the arcuate portion 152 of the outermost comb pattern 15A is preferably greater than the thickness of the spacer 30. This opening 31 is formed at a position corresponding to the arcuate portion 152 of the comb patterns 15A to 15I of the lower film substrate 10 and the connector 22 of the upper film substrate 20. When the lower film substrate 10 and the upper film substrate 20 are deposited via the spacer 30, the arcuate portion 152 of the comb pattern 15A to 15I faces the connector 22 through the opening 31, and the front end portion 161 of the wiring pattern 16 also faces the connector 22.

[0059] Furthermore, the planar shape of the opening 31 is not limited to a circle; for example, it can be an ellipse, oblong, rectangular, or polygonal shape. In addition, the shapes of the connector 22 and the detection portions 155 of the comb patterns 15A to 15I are also not particularly limited to the above; for example, they can be shaped to correspond to the shape of the opening 31. The portion of the upper film substrate 20 in the substrate 21 facing this opening 31 corresponds to an example of the "pressing portion" in the present invention.

[0060] The lower film substrate 10 and the upper film substrate 20 are laminated together via spacer 30. Specifically, the upper surface 111 of the substrate 11 of the lower film substrate 10 and the lower surface of the spacer 30 are attached to each other via an adhesive layer (not shown). At the same time, the upper surface of the spacer 30 and the lower surface 212 of the substrate 21 of the upper film substrate 20 are attached to each other via an adhesive layer (not shown).

[0061] At this time, as shown in Figure 1, in the top view, the center CP of the opposing region 113 of the lower film substrate 10 coincides with the center of the opening 31 of the spacer 30. Furthermore, in the top view, the aforementioned center CP coincides with the center of the front end portion 161 of the wiring pattern 16 of the lower film substrate 10, and also coincides with the center of the connector 22 of the upper film substrate 20. Moreover, via the opening 31 of the spacer 30, the connector 22 of the upper film substrate 20 faces the front end portion 161 of the wiring pattern 16 of the lower film substrate 10 and the arcuate portions 152 of the comb patterns 15A to 15I.

[0062] As shown in Figure 2, the spacer 30 ensures the spacing between the connector 22 and the front end 161 of the wiring pattern 16, and also ensures the spacing between the connector 22 and the comb patterns 15A to 15I. As described below, the substrate 21 of the upper film substrate 20 deforms under the load applied by the pressing member. Through this deformation, the connector 22 contacts and is electrically connected to the front end 161 of the wiring pattern 16, and at the same time, the connector 22 contacts and is electrically connected to the comb patterns 15A to 15I.

[0063] Furthermore, in this embodiment, although the thickness of the spacer 30 is set such that the connector 22 does not contact the comb patterns 15A to 15I and the wiring pattern 16 when not pressed, it is not particularly limited to this. The thickness of the spacer 30 may also be set such that the connector 22 continuously contacts the comb patterns 15A to 15I and the wiring pattern 16.

[0064] Here, in this embodiment, the so-called "electrical connection" between the connector and the comb pattern refers to a state where the resistance value between the connector and the comb pattern is less than a predetermined threshold, and does not include the state where the connector and the comb pattern are merely in contact when not pressed, as described above. Similarly, in this embodiment, the so-called "electrical connection" between the connector and the wiring pattern refers to a state where the resistance value between the connector and the wiring pattern is less than a predetermined threshold, and does not include the state where the connector and the wiring pattern are merely in contact when not pressed, as described above.

[0065] As shown in Figure 2, the spacer 40 is disposed between the lower surface 112 of the substrate 11 of the lower membrane substrate 10 and the support surface 71 of the support body 70 that supports the pressure sensor 1A. As a specific example of the support body 70, a housing such as a controller housing that houses the pressure sensor 1A can be exemplified.

[0066] This spacer 40 is a thin film sheet made of an electrically insulating material. Examples of materials constituting this spacer 40 include resin materials, and more specifically, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). The spacer 40 is attached to the lower surface 112 of the substrate 11 of the lower film substrate 10 via an adhesive layer (not shown).

[0067] As shown in Figure 1, the spacer 40 has a circular planar shape that is approximately the same size as the enlarged diameter portion 161 of the wiring pattern 16. In a top view, the spacer 40 is configured to overlap with the connector 22 of the upper film substrate 20 and also with the opposing region 113 of the upper surface 111 of the substrate 11 of the lower film substrate 10. Although not particularly limited, in a top view, the center of the spacer 40 coincides with the center CP of the opposing region 113 of the lower film substrate 10.

[0068] As shown in Figure 2, the opposing region 113 of the substrate 11 has a highest point 114, which is higher than the other parts of the opposing region 113 (the parts of the opposing region 113 other than the highest point 114) by means of the spacer 40. In addition, this opposing region 113 has an inclined surface 115 extending from the highest point 114.

[0069] Specifically, since the spacer 40 is disposed in the center of the opposing region 113, the highest part 114 is also located in the center of the opposing region 113. Although not particularly limited, in a top view, the center of this highest part 114 is also consistent with the center CP of the opposing region 113 of the lower film substrate 10.

[0070] The inclined surface 115 extends radially in the radial direction of the opposing region 113 from the entire circumference of the highest part 114 toward the outer periphery of the opposing region 113. This inclined surface 115 is inclined in such a way that it descends from the highest part 114 toward the outer periphery of the opposing region 113 on the -Z side in the figure. This inclined surface 115 as a whole has a shape equivalent to the outer peripheral surface (lateral surface) of a truncated cone.

[0071] The enlarged diameter portion 161 of the wiring pattern 16 of the lower film substrate 10 is disposed at the highest portion 114 of the opposing region 113. On the other hand, the comb patterns 15A to 15I of the lower film substrate 10 are disposed on the inclined surface 115 of the opposing region 113. In this embodiment, the comb pattern 15A corresponds to an example of the "first comb pattern" and an example of the "third comb pattern" in the present invention, the comb patterns 15B to 15H correspond to an example of the "first comb pattern" in the present invention, and the comb pattern 15I corresponds to an example of the "first comb pattern" and an example of the "second comb pattern" in the present invention.

[0072] Furthermore, the shape of the spacer 40 is not particularly limited to the above description, as long as the highest part 114 is formed in the opposing region 113. For example, instead of the spacer 40, a spacer 41 having a truncated conical shape as shown in Figure 5 can also be used. Figure 5 is a cross-sectional view of a pressure sensor 1A including the spacer 41, and the spacer 41 is a variation of the spacer 40 in an embodiment of the present invention. Furthermore, when using this spacer 41, the spacer 41 is connected to the lower surface 112 of the substrate 11 only through the uppermost part of the spacer 41, and preferably no adhesive is provided between the inclined surface of the spacer 41 and the lower surface 112 of the substrate 11.

[0073] The operation of the pressure sensor 1A described above will be explained with reference to Figures 6(a) to 7(c).

[0074] Figures 6(a) to 6(c) are cross-sectional views showing the operation of the pressure sensor 1A in this embodiment. Figure 6(a) is a schematic diagram showing the state in which the connector 22 begins to contact the comb pattern 15I. Figure 6(b) is a schematic diagram showing the state in which a load is applied even more than that shown in Figure 6(a). Figure 6(c) is a schematic diagram showing the state in which a load is applied even more than that shown in Figure 6(b). In addition, Figure 7(a) is a graph showing the output characteristics of the pressure sensor 1A in this embodiment. Figure 7(b) is a graph showing the output characteristics of the pressure sensor in Comparative Example 1. Figure 7(c) is a graph showing the output characteristics of the pressure sensor in Comparative Example 2.

[0075] Before a load is applied to the pressure sensor 1A, the connector 22 does not contact either the comb patterns 15A to 15I or the wiring pattern 16. Therefore, as shown in Figure 7(a), the pressure sensor 1A outputs an infinitely large resistance value as the resistance value between the wiring patterns 12 and 16. Furthermore, although not specifically illustrated, for example, the wiring patterns 12 and 16 are connected to an external device, and a predetermined voltage is applied to the wiring pattern 16 from this external device, which includes a resistance measuring unit that measures the resistance value between the wiring patterns 12 and 16.

[0076] Furthermore, Figure 7(a) is a graph showing the output characteristics (F (load) - R (resistance) characteristics) of the pressure sensor 1A in this embodiment. The horizontal axis represents the load applied to the pressure sensor 1A, and the vertical axis represents the resistance value between the wiring patterns 12 and 16, which varies corresponding to the applied load. The resistance value between the wiring patterns 12 and 16 varies according to the connection position of the comb patterns 15A to 15I connected to the wiring patterns 16 via the connector 22 in the resistor body 14. Therefore, as shown in Figure 7(a), the output of the pressure sensor 1A is stepped. Therefore, the more comb patterns there are and the narrower the intercept of the comb patterns, the higher the resolution of the pressure sensor 1A can be.

[0077] When the pressure sensor 1A is pressed by the pressing member (not shown), as shown in Figure 6(a), the substrate 21 of the upper film substrate 20 is recessed from the center of the opening 31 of the spacer 30. Thereby, the connector 22 disposed on the lower surface 212 of the substrate 21 initially contacts the front end 161 of the wiring pattern 16 of the lower film substrate 10, while the connector 22 only contacts the innermost comb pattern 15I. The innermost comb pattern 15I is connected to the second end 142 of the resistor 14 furthest from the first end 141. Therefore, as shown in Figure 7(a), the pressure sensor 1A outputs a high resistance value R1 as the resistance value between the wiring patterns 12 and 16. Furthermore, the load F1 corresponding to this resistance value R1 is the so-called "loaded" state at the beginning of the electrical connection between the wiring patterns 12 and 16.

[0078] Here, although not specifically illustrated, the pressing member is, for example, a component made of resin material, supported above the upper film substrate 20, so as to approach or move away from the upper surface 211 of the substrate 21 of the upper film substrate 20. In this embodiment, the pressing member is configured such that the center of the pressing member coincides with the center of the opening 31 of the spacer 30 (the center CP of the opposing region 113 of the substrate 11 of the lower film substrate 10), and is configured such that when the upper film substrate 20 is pressed by the pressing member, the connector 22 first contacts the front end 161 of the wiring pattern 16 and the innermost comb pattern 15I. As a specific example of such a pressing member, the operation key of a controller can be exemplified. Furthermore, the pressing member can also be the operator's finger.

[0079] Furthermore, as the pressing force (applied load) of the pressing member increases, the recessed portion of the substrate 21 of the upper film substrate 20 becomes larger, and the connection object of the connector 22 gradually expands to the outermost comb pattern 15H to 15A. As a result, because the distance between the end 141 on the resistor 14 side and the connection position of the aforementioned connection object becomes shorter, the resistance value between the wiring pattern 12 and the wiring pattern 16 decreases.

[0080] In this way, in this embodiment, the outermost comb pattern in the comb pattern that contacts the connector 22 changes, causing a change in the position where the resistor 14 is connected to the wiring pattern 16 via the connector 22 and the comb patterns 15A to 15I. Therefore, the distance between the end 141 on one side of the resistor 14 and the aforementioned connection position changes. That is, in the pressure sensor 1A of this embodiment, the resistance length (resistance value) of the resistor 14 changes in response to the pressing force applied by the pressing member.

[0081] For example, as shown in Figure 6(b), the load is increased compared to the state in Figure 6(a). In addition to the wiring pattern 16 and the comb pattern 15I, the connector 22 also contacts the comb pattern 15H. As shown in Figure 7(a), the pressure sensor 1A outputs a resistance value R2 that is smaller than the resistance value R1 mentioned above as the resistance value between the wiring pattern 12 and the wiring pattern 16.

[0082] Here, in the pressure sensor of Comparative Example 1 excluding the spacer 40, as described above, there may be a situation where air bubbles remaining between the substrate and the support cause a rapid change in resistance. For example, as shown in Figure 7(b), if the resistance value decreases by a change ΔR for each additional comb pattern that contacts the connector, when a load F' is applied, because the air bubbles cause the connector to contact three comb patterns simultaneously, the resistance change (ΔR×3) becomes three times the predetermined value (ΔR).

[0083] In contrast, in this embodiment, as described above, the comb patterns 15A to 15I are arranged on the inclined surface 115 of the opposing region 113. Therefore, when the connector 22 contacts the outermost comb patterns 15H to 15A, the connector 22 contacts the comb patterns 15H to 15A one by one in sequence. Thus, as shown in Figure 7(a), the change in resistance value output by the pressure sensor 1A can be a uniform stepped shape, improving the linearity of the pressure sensor 1A's output.

[0084] Furthermore, the pressing parts may have individual differences such as dimensional variations. In the pressure sensor of Comparative Example 2, where all comb pattern widths are the same, this individual difference in the pressing parts affects the resistance value in the low load range. For example, in the example shown in Figure 7(c), the resistance value at the beginning of pressing differs for each pressing part (first pressing part to third pressing part), and the resistance value is unstable in the low load range.

[0085] In contrast, in this embodiment, in the opposing region 113, because the width w1 of the innermost comb pattern 15I is wider than the width w0 of the other comb patterns 15A to 15H (w1 > w0), the resistance value is stable in the low load range even if the pressing element has individual differences. For example, as shown in Figure 7(a), the resistance value from the start of pressing until the connector 22 contacts the comb pattern 15H is significantly stable, thus improving the linearity of the pressure sensor 1A output.

[0086] When a load is applied more than that in Figure 6(b) and the pressure sensor 1A is fully pressed, as shown in Figure 6(c), the connector 22 comes into contact with the wiring pattern 16 and all the comb patterns 15A to 15I. At this time, the outermost comb pattern 15A is in direct contact with the wiring pattern 12, so the resistance between the wiring pattern 12 and the wiring pattern 16 becomes essentially zero.

[0087] When the pressing of the pressing member is released, the opposite operation is performed. That is, as the applied load decreases, the recessed portion of the substrate 21 of the upper film substrate 20 becomes smaller, and the connection object of the connector 22 gradually narrows to the inner comb pattern 15A to 15I. As a result, because the distance between the end 141 on the resistor 14 side and the connection position of the aforementioned connection object becomes longer, the resistance value between the wiring pattern 12 and the wiring pattern 16 increases.

[0088] As described above, in this embodiment, the spacer 40 is disposed on the lower surface 112 of the substrate 11, and the upper surface 111 of the substrate 11 has a highest portion 114 that is higher than other parts of the upper surface 111 by means of the spacer 40, and an inclined surface 115 extending from the highest portion 114. In a top view, a plurality of comb patterns 15A to 15H overlap with the inclined surface 115. Therefore, the plurality of comb patterns 15A to 15I can sequentially contact the connector 22, thereby improving the output characteristics of the pressure sensor 1A.

[0089] <<Second Embodiment>> Figure 8 is a top view showing the pressure sensor 1B in the second embodiment of the present invention, Figure 9 is a cross-sectional view along line segment IX-IX in Figure 8, Figure 10 is a top view showing the lower membrane substrate 10 in this embodiment, and Figure 11 is a bottom view showing the spacer 30 and the upper membrane substrate 20 in this embodiment.

[0090] As shown in Figures 8 to 11, the pressure sensor 1B of this embodiment differs from the pressure sensor 1A of the first embodiment in that (1) the wiring pattern 16 is disposed on the upper substrate 21 and directly connected to the connector 22, and (2) the straight comb patterns 15A to 15I do not have arcuate portions 152 and extend in a straight line on the opposing region 113. However, the structure is otherwise similar to that of the first embodiment. In the following description, only the differences between the pressure sensor 1B of the second embodiment and the first embodiment will be explained. For structures identical to those of the first embodiment, the same reference numerals will be used and the description will be omitted.

[0091] As shown in Figures 9 and 11, in this embodiment, the wiring pattern 16 is formed on the lower surface 212 of the substrate 21 of the upper film substrate 20. This wiring pattern 16 is formed integrally with the connector 22 and is directly connected to the connector 22. Furthermore, when a metal thin film is used as the substrate 21, the substrate 21 can have the function of the connector 22, and the substrate 21 can also have the function of the wiring pattern 16.

[0092] Furthermore, as shown in Figures 8 and 10, the plurality of comb tooth patterns 15A to 15I do not have arcuate portions 152, but are only composed of straight portions 151, and these straight portions 151 extend linearly along the X direction in the figures in the opposing region 113. In this embodiment, the straight portions 151 of the plurality of comb tooth patterns 15A to 15I are arranged in half of the lower side (Y side in the figures) of the opposing region 113, and are spaced apart and substantially parallel to each other from the center CP of the opposing region 113 outward.

[0093] Furthermore, in this embodiment, the pressing start position of the pressing member can be set at any position within the opposing region 113 other than the center CP. In this case, the straight portions of the comb pattern are arranged from the aforementioned pressing start position other than the center CP of the opposing region 113, spaced apart and substantially parallel to each other, toward the outside of the opposing region 113.

[0094] As shown in Figures 9 and 10, in this embodiment, a portion of the innermost comb pattern 15I of the lower film substrate 10 is disposed at the highest portion 114 of the opposing region 113. On the other hand, other comb patterns 15A to 15H of the lower film substrate 10 are disposed on the inclined surface 115 of the opposing region 113. In this embodiment, comb pattern 15A corresponds to an example of the "first comb pattern" and an example of the "third comb pattern" in the present invention, comb patterns 15B to 15H correspond to an example of the "first comb pattern" in the present invention, and comb pattern 15I corresponds to an example of the "second comb pattern" in the present invention.

[0095] In the pressure sensor 1B of this embodiment, similar to the first embodiment, the position of the resistor 14 connected to the wiring pattern 16 via the connector 22 and the comb pattern 15A to 15I changes according to the magnitude of the pressing force (applied load) of the pressing member (not shown), so the resistance value between the wiring pattern 12 and the wiring pattern 16 changes.

[0096] As described above, in this embodiment, the spacer 40 is disposed on the lower surface 112 of the substrate 11, and the upper surface 111 of the substrate 11 has a highest point 114 and an inclined surface 115. In a top view, a plurality of comb patterns 15A to 15H overlap with the inclined surface 115. Therefore, the plurality of comb patterns 15A to 15H can sequentially contact the connector 22, thereby improving the output characteristics of the pressure sensor 1B.

[0097] Furthermore, in this embodiment, in the opposing region 113, because the width of the innermost comb pattern 15I is wider than the widths of the other comb patterns 15A to 15H, the resistance value is stable in the low load range even if the pressing element has individual differences.

[0098] Furthermore, as shown in Figure 12, in a top view, the innermost comb pattern 15I of the lower film substrate 10 may not overlap with the highest portion 114 of the opposing region 113. In this case, in a top view, the highest portion 114 is closer to the innermost comb pattern 15I than the second innermost comb pattern 15H. Figure 12 is a top view showing a variation of the lower film substrate 10 in the second embodiment of the present invention. In this variation, comb pattern 15A corresponds to an example of the "first comb pattern" and an example of the "third comb pattern" in the present invention, comb patterns 15B to 15H correspond to an example of the "first comb pattern" in the present invention, and comb pattern 15I corresponds to an example of the "first comb pattern" and an example of the "second comb pattern" in the present invention.

[0099] <<Third Embodiment>> Figure 13 is a top view showing the lower membrane substrate 10 of the pressure sensor in the third embodiment of the present invention.

[0100] As shown in Figure 13, the pressure sensor of this embodiment differs from the pressure sensor 1B of the second embodiment in that (1) the wiring pattern 16 is disposed on the lower substrate 11, and (2) the wiring pattern 16 extends parallel to the innermost comb pattern 15I in the opposing region 113, but otherwise the structure is similar to that of the second embodiment. In the following, only the differences between the pressure sensor of the third embodiment and the second embodiment will be described, and the same reference numerals will be used for structures identical to those of the second embodiment, and descriptions will be omitted.

[0101] As shown in Figure 13, in this embodiment, the wiring pattern 16 is formed on the upper surface 111 of the substrate 11 of the lower film substrate 10. This wiring pattern 16 extends linearly along the X direction in the opposing region 113 and extends parallel to the innermost comb pattern 15I.

[0102] In this embodiment, a portion of the wiring pattern 16 is disposed at the highest portion 114 of the opposing region 113. On the other hand, the comb patterns 15A to 15I of the lower film substrate 10 are disposed on the inclined surface 115 of the opposing region 113. In this embodiment, the comb pattern 15A corresponds to an example of the "first comb pattern" and an example of the "third comb pattern" in the present invention, the comb patterns 15B to 15H correspond to an example of the "first comb pattern" in the present invention, and the comb pattern 15I corresponds to an example of the "first comb pattern" and an example of the "second comb pattern" in the present invention.

[0103] In the pressure sensor of this embodiment, similar to the second embodiment, the position of the resistor 14 connected to the wiring pattern 16 via the connector 22 and the comb patterns 15A to 15I changes according to the magnitude of the pressing force (applied load) of the pressing member (not shown), so the resistance value between the wiring pattern 12 and the wiring pattern 16 changes.

[0104] As described above, in this embodiment, the spacer 40 is disposed on the lower surface 112 of the substrate 11, and the upper surface 111 of the substrate 11 has a highest point 114 and an inclined surface 115. In a top view, a plurality of comb patterns 15A to 15I overlap with the inclined surface 115. Therefore, the plurality of comb patterns 15A to 15I can sequentially contact the connector 22, thereby improving the output characteristics of the pressure sensor.

[0105] Furthermore, in this embodiment, in the opposing region 113, because the width of the innermost comb pattern 15I is wider than the widths of the other comb patterns 15A to 15H, the resistance value is stable in the low load range even if the pressing element has individual differences.

[0106] Furthermore, as shown in Figure 14, in a top view, the wiring pattern 16 and the highest part 114 of the opposing region 113 may not overlap. In this case, in a top view, the highest part 114 is closer to the wiring pattern 16 than the innermost comb pattern 15I. Furthermore, Figure 14 is a top view showing a variation of the lower film substrate 10 in the third embodiment of the present invention. In this variation, the comb pattern 15A corresponds to an example of the "first comb pattern" and an example of the "third comb pattern" in the present invention, the comb patterns 15B to 15H correspond to an example of the "first comb pattern" in the present invention, and the comb pattern 15I corresponds to an example of the "first comb pattern" and an example of the "second comb pattern" in the present invention.

[0107] <<Fourth Embodiment>> Figure 15 is a cross-sectional view showing the pressure sensor 1D in the fourth embodiment of the present invention.

[0108] As shown in Figure 15, the pressure sensor 1D of this embodiment differs from the pressure sensor 1A of the first embodiment in that (1) a pressing member 50 is included instead of the upper substrate 21, and (2) a supporting member 60 is included instead of the spacer 30. Otherwise, the structure is similar to that of the first embodiment. In the following, only the differences between the pressure sensor 1D of the fourth embodiment and the first embodiment will be described. For structures that are the same as those in the first embodiment, the same reference numerals will be used and the description will be omitted.

[0109] The pressing member 50 is made of an elastic material with electrical insulation properties, such as silicone rubber. Furthermore, in this embodiment, instead of the substrate 21, a connector 22 is formed on the lower surface of the pressing member 50. In this embodiment, the opposing region 113 of the substrate 11 of the lower film substrate 10 is the region on the upper surface 111 of the substrate 11 that faces the connector 22.

[0110] Furthermore, in this embodiment, although the pressing member 50 has a circular planar shape corresponding to the arcuate portion 152 of the comb tooth patterns 15A to 15I, the planar shape of the pressing member 50 is not particularly limited to this. For example, the planar shape of the pressing member 50 may also have a strip-shaped planar shape corresponding to a portion of the arcuate portion 152 of the comb tooth patterns 15A to 15I. In this case, the pressing member 50 only needs to partially overlap with all the comb tooth patterns 15A to 15I.

[0111] The support member 60 is also made of an elastic material such as silicone rubber, and is disposed around the opposing region 113 of the substrate 11 of the lower film substrate 10. The pressing member 50 is supported on the support member 60, so that the connector 22 faces the detection part 155 of the comb pattern 15A to 15I and the front end 161 of the wiring pattern 16. In this embodiment, in the top view, the center CP of the opposing region 113 is substantially coincident with the center of the front end 161 of the wiring pattern 16, and is also substantially coincident with the center of the lower surface of the pressing member 50.

[0112] The connecting body 22, the pressing member 50 and the supporting member 60 are equivalent to an example of the "pressing device" in the present invention, and the pressing member 50 is equivalent to an example of the "pressing part" in the present invention.

[0113] The pressure sensor 1D in this embodiment is also similar to the first embodiment. Corresponding to the magnitude of the pressing force (applied load) of the pressing member 50, the position of the resistor 14 connected to the wiring pattern 16 via the connector 22 and the comb pattern 15A to 15I changes, so the resistance value between the wiring pattern 12 and the wiring pattern 16 changes.

[0114] As described above, in this embodiment, the spacer 40 is disposed on the lower surface 112 of the substrate 11, and the upper surface 111 of the substrate 11 has a highest point 114 and an inclined surface 115. In a top view, a plurality of comb patterns 15A to 15H overlap with the inclined surface 115. Therefore, the plurality of comb patterns 15A to 15I can sequentially contact the connector 22, thereby improving the output characteristics of the pressure sensor 1D.

[0115] Furthermore, the embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments are also intended to include all design changes and equivalents that fall within the scope of the present invention.

[0116] For example, in the first embodiment described above, although the wiring pattern 16 is formed on the upper surface of the substrate 11 of the lower film substrate 10, it is not particularly limited to this. Specifically, in the embodiments shown in Figures 1 to 4, similar to the second embodiment, the wiring pattern 16 may also be formed on the lower surface 212 of the substrate 21 of the upper film substrate 20, and the wiring pattern 16 may be directly connected to the connector 22.

[0117] Furthermore, in the fourth embodiment, although the wiring pattern 16 is formed on the upper surface of the substrate 11 of the lower film substrate 10, it is not particularly limited to this. Specifically, in the embodiment shown in Figure 15, the wiring pattern 16 may also be formed on the support member 60, and the wiring pattern 16 may be directly connected to the connector 22.

[0118] Furthermore, in the second to fourth embodiments, instead of the spacer 40, a spacer 41 having a truncated conical shape as shown in Figure 5 may also be used.

[0119] Furthermore, in the first embodiment described above, although a predetermined voltage is applied to the wiring pattern 12 and the wiring pattern 16 and the resistance value between the wiring pattern 12 and the wiring pattern 16 is obtained, the circuit structure used to obtain the resistance value between the wiring pattern 12 and the wiring pattern 16 is not particularly limited thereto.

[0120] For example, as shown in Figure 16, the wiring pattern 13 connected to the other end 142 of the resistor 14 can also be provided on the substrate 11. Figure 16 is a top view showing the lower membrane substrate 10 of the pressure sensor in the fifth embodiment of the present invention.

[0121] As shown in Figure 16, wiring pattern 13 is covered by end 142 on the other side of resistor 14, and wiring pattern 12 and wiring pattern 13 are electrically connected via resistor 14. Furthermore, end 131 of wiring pattern 13 is directly connected to the innermost comb pattern 15I. While wiring pattern 12 is connected to the power supply, wiring pattern 13 is grounded, and a voltage corresponding to the resistance value between wiring pattern 12 and wiring pattern 16 can be obtained from wiring pattern 16. [Simplified Explanation of the Diagram]

[0022] Figure 1 is a top view showing the pressure sensor in the first embodiment of the present invention. Figure 2 is a cross-sectional view along line II-II in Figure 1. Figure 3 is a top view showing the lower membrane substrate in the first embodiment of the present invention. Figure 4 is a bottom view showing the spacer and the upper membrane substrate in the embodiment of the present invention. Figure 5 is a cross-sectional view of the pressure sensor, showing a variation example of the spacer in the embodiment of the present invention. Figures 6(a) to 6(c) are cross-sectional views showing the operation of the pressure sensor in the first embodiment of the present invention. Figure 6(a) is a schematic diagram of the state in which the connector begins to contact the comb pattern. Figure 6(b) is a schematic diagram of the state in which a load is applied even more than that in Figure 6(a). Figure 6(c) is a schematic diagram of the state in which a load is applied even more than that in Figure 6(b). Figure 7(a) is a graph showing the output characteristics of the pressure sensor in the first embodiment of the present invention; Figure 7(b) is a graph showing the output characteristics of the pressure sensor in Comparative Example 1; and Figure 7(c) is a graph showing the output characteristics of the pressure sensor in Comparative Example 2. Figure 8 is a top view showing the pressure sensor in the second embodiment of the present invention. Figure 9 is a cross-sectional view along line IX-IX in Figure 8. Figure 10 is a top view showing the lower membrane substrate in the second embodiment of the present invention. Figure 11 is a bottom view showing the spacer and the upper membrane substrate in the second embodiment of the present invention. Figure 12 is a top view showing a variation of the lower membrane substrate in the second embodiment of the present invention. Figure 13 is a top view showing the lower membrane substrate of the pressure sensor in the third embodiment of the present invention. Figure 14 is a top view showing a variation of the lower membrane substrate of the pressure sensor in the third embodiment of the present invention. Figure 15 is a cross-sectional view showing the pressure sensor in the fourth embodiment of the present invention. Figure 16 is a top view showing the lower membrane substrate of the pressure sensor in the fifth embodiment of the present invention.

Claims

1. A pressure sensor, comprising: The first substrate has a first main surface and a second main surface; A resistor is disposed on the first main surface; A first wiring pattern is disposed on the first main surface and connected to the resistor; A plurality of comb-tooth patterns are disposed on the first main surface and each is independently connected to the resistive element; a pressing device includes: a pressing portion facing the comb-tooth patterns and accessible to the first main surface, and a connecting body held on the pressing portion and electrically connected to the comb-tooth patterns by pressing the pressing portion; a second wiring pattern is disposed on the first main surface and electrically connected to the connecting body by pressing the pressing portion, or is included in the pressing device and connected to the connecting body; and a first spacer is disposed on the second main surface; wherein, in a top view, the resistive element is positioned at a position that does not overlap with the connecting body; wherein the first main surface includes: a highest portion that is higher than other portions of the first main surface by means of the first spacer; and an inclined surface extending from the highest portion; wherein, in a top view, the plurality of comb-tooth patterns include a plurality of first comb-tooth patterns that overlap with the inclined surface; wherein, the resistance value between the first wiring pattern and the second wiring pattern changes corresponding to the load applied to the pressing portion.

2. The pressure sensor as described in claim 1, wherein, In a top view, the first spacer overlaps with the connector; The area opposite to the first main surface facing the connector includes: the highest part; And the inclined surface.

3. The pressure sensor as described in claim 1, wherein, The second wiring pattern is disposed on the first main surface; in a top view, the highest part overlaps with the second wiring pattern.

4. The pressure sensor as described in claim 1, wherein, The second wiring pattern is disposed on the first main surface; the first wiring pattern is connected to the first end of the resistor; the plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor; the plurality of comb patterns includes a second comb pattern connected to the second end of the resistor; in a top view, the highest part is closer to the second wiring pattern than the second comb pattern.

5. The pressure sensor as described in claim 3 or 4, wherein, The pressing device includes: a second substrate on which the connector is disposed; and a second spacer between the first substrate and the second substrate; the second spacer having an opening that aligns the connector with the second wiring pattern and the comb pattern.

6. The pressure sensor as described in claim 1, wherein, The second wiring pattern is included in the pressing device and connected to the connector; the first wiring pattern is connected to the first end of the resistor; the plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor; the plurality of comb patterns includes a second comb pattern connected to the second end of the resistor; in a top view, the highest part overlaps with the second comb pattern.

7. The pressure sensor as described in claim 1, wherein, The second wiring pattern is included in the pressing device and connected to the connector; the first wiring pattern is connected to the first end of the resistor; the plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor; the plurality of comb patterns includes a second comb pattern connected to the second end of the resistor; in a top view, the highest part is closer to the second comb pattern than the other comb patterns.

8. The pressure sensor as described in claim 6 or 7, wherein, The pressing device includes: a second substrate having the connector and the second wiring pattern thereon; and a second spacer between the first substrate and the second substrate; the second spacer having an opening that aligns the connector with the comb pattern.

9. The pressure sensor as described in claim 1, wherein, The first wiring pattern is connected to the first end of the resistor; the plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor; the plurality of comb patterns includes a second comb pattern connected to the second end of the resistor; in the opposing region of the first main surface opposite to the connector, the width of the second comb pattern is wider than the widths of the other comb patterns.

10. The pressure sensor as described in claim 1, wherein, In the opposing region of the first main surface opposite to the connector, the plurality of comb patterns are spaced apart from each other and arranged side by side.

11. The pressure sensor as described in claim 10, wherein, The first wiring pattern is connected to the first end of the resistor; the plurality of comb patterns are spaced apart from each other and connected between the first end and the second end of the resistor; the plurality of comb patterns are disposed on the first main surface such that the closer the connection position of the comb patterns with the resistor is to the second end, the closer the comb patterns are to the highest point.

12. The pressure sensor as described in claim 10 or 11, wherein, In a top view, the plurality of comb-like patterns are arranged in concentric circles around the highest point.

13. The pressure sensor as described in claim 1, wherein, The plurality of comb patterns include a third comb pattern connected to a first end of the resistor; the first wiring pattern is connected to the third comb pattern.

14. The pressure sensor as described in claim 1, wherein, The first spacer is disposed between the support body and the second main surface, the support body having a support surface that supports the pressure sensor.

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