Pressure sensor

Abstract

To provide a pressure sensitive sensor that can achieve a reduction in thickness and the number of components, and avoids the possibility that displacement between constituents occurs due to assembly.SOLUTION: A first contact pattern 21 and a first wiring pattern 31 are formed on a substrate 10. A first pressure-sensitive resistor 41 in which the value of resistance changes according to pressure is formed on the first contact pattern 21. An insulating layer 71 having an opening 73 and conductive layers 81, 85 closing the opening 73 are formed on the first pressure-sensitive resistor 41. A second pressure-sensitive resistor 45 in which the value of resistance changes according to pressure is formed on the insulating layer 71 including the conductive layers 81, 85. A second contact pattern 51 is formed at a position on the second pressure-sensitive resistor 45 opposite to the first contact pattern 21. A second wiring pattern 61 connected with the second contact pattern 51 is led out onto the substrate 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pressure-sensitive sensor whose resistance value changes according to the pressing force.

Background Art

[0002] Conventionally, as shown in, for example, Patent Document 1, a pressure-sensitive sensor whose resistance value changes according to the pressing force is configured by laminating a lower circuit board provided with a lower electrode and an upper circuit board provided with an upper electrode via a spacer. At this time, the upper electrode and the lower electrode are opposed to each other within an opening provided in the spacer, and the upper circuit board on the back side of the upper electrode is pressed to lower it, so that the upper electrode comes into contact with the lower electrode, and the resistance value between the upper electrode and the lower electrode is changed according to the magnitude (contact area) of the contact force (load).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the conventional pressure-sensitive sensor is configured using two circuit boards and a spacer as described above, the number of components increases, the thickness dimension of the product becomes thick, and there is a risk that the position of the opening of the spacer and the upper electrode may shift with respect to the lower electrode due to the shift during the assembly of the two circuit boards and the spacer.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide a pressure-sensitive sensor capable of reducing the number of components and thinning the thickness, and having no risk of displacement due to assembly between the respective components.

Means for Solving the Problems

[0006] In a pressure-sensitive sensor whose resistance value changes according to the applied pressure, a first contact pattern and a first wiring pattern connected to the first contact pattern are formed on a substrate. A first pressure-sensitive resistor whose resistance value changes according to pressure is formed on the first contact pattern. An insulating layer having an opening and a conductive layer closing the opening are formed on the first pressure-sensitive resistor. A second pressure-sensitive resistor whose resistance value changes according to pressure is formed on the insulating layer including the conductive layer. A second contact pattern is formed at a position facing the first contact pattern on the second pressure-sensitive resistor, and a second wiring pattern connected to the second contact pattern is drawn out on the substrate. According to the present invention, since a pressure-sensitive sensor can be configured by forming various patterns on a single substrate, the number of components can be reduced and the thickness can be made thinner. Also, there is no possibility of misalignment due to assembly between the first and second contact patterns, the first and second pressure-sensitive resistors, the conductive layer, and the insulating layer. Further, since no space is provided by a spacer between the first contact pattern and the second contact pattern as in the prior art, a change in the resistance value starts with the application of a light force. Therefore, it is suitable for use as a pressure-sensitive sensor that requires a characteristic in which a change in the resistance value starts with a light force and further changes as the applied pressure increases. Also, since the thicknesses of the first and second pressure-sensitive resistors are thin, the first contact pattern is conductive only in the portion facing the conductive layer vertically (directly above and below), and the second contact pattern is conductive only in the portion facing the conductive layer vertically (directly above and below) (since a change in the resistance value occurs). By adjusting the area and shape of the conductive layer and the first and second contact patterns facing it, the resistance value can be easily and accurately adjusted (for example, when the area of the conductive layer is reduced, the resistance value increases). Also, since the electric circuit of this pressure-sensitive sensor has a structure in which the first and second pressure-sensitive resistors are connected in series, the resistance value of this pressure-sensitive sensor can be increased, and a pressure-sensitive sensor with high resolution can be obtained.

[0007] In addition to the above features, the present invention is characterized in that the conductive layer is filled inside the opening of the insulating layer and is formed so as to cover at least a part of the surface of the insulating layer around the opening. According to the present invention, by forming the conductive layer from the inside to the periphery of the opening of the insulating layer, the entire opening can be surely blocked by the conductive layer.

[0008] In addition to the above features, the present invention is characterized in that the second pressure-sensitive resistor is formed so as to cover the upper surface and the side surface of the conductive layer. Thereby, the second pressure-sensitive resistor located directly above the entire upper surface of the conductive layer can act as a resistor of the electric circuit.

[0009] In addition to the above features, the present invention is characterized in that the second wiring pattern is drawn out on the substrate in contact with the upper surface or the side surface of the second pressure-sensitive resistor and the upper surface or the side surface of the insulating layer. Thereby, the second wiring pattern can be drawn out on the substrate.

[0010] In addition to the above features, the present invention is characterized in that the first contact pattern, the first wiring pattern, the first pressure-sensitive resistor, the insulating layer, the conductive layer, the second pressure-sensitive resistor, and the second contact pattern and the second wiring pattern are laminated and formed on the substrate by printing. Thereby, various patterns can be easily and accurately formed at the correct positions on a single substrate, reducing the number of parts, reducing the manufacturing cost, and making the thickness thinner. Also, there is no longer any risk of misalignment due to assembly at the positions of various patterns.

Advantages of the Invention

[0011] According to the present invention, the number of parts can be reduced and the thickness can be made thinner. Also, there is no longer any risk of misalignment due to assembly between the respective components, and a pressure sensor with stable product characteristics can be obtained.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3-1

Figure 3-2

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of the pressure sensor 1 according to an embodiment of the present invention (schematic cross-sectional view taken along line A-A in FIG. 2), and FIG. 2 is a schematic plan view of the pressure sensor 1. As shown in these figures, the pressure sensor 1 forms a first contact pattern 21 and a first wiring pattern 31 connected to the first contact pattern 21 on a substrate 10, and a first pressure-sensitive resistor (first pressure-sensitive resistance layer, first pressure-sensitive resistance pattern) 41 whose resistance value changes according to pressure is formed on the first contact pattern 21. A first conductive layer 81 is formed on the first pressure-sensitive resistor 41, and an insulating layer 71 having an opening 73 for exposing a part of the first conductive layer 81 is formed on the first pressure-sensitive resistor 41. A second conductive layer 85 is formed on the insulating layer 71 including the opening 73, and a second pressure-sensitive resistor (second pressure-sensitive resistance layer, second pressure-sensitive resistance pattern) 45 whose resistance value changes according to pressure is formed on the insulating layer 71 including the second conductive layer 85. A second contact pattern 51 is formed at a position facing the first contact pattern 21 above the second pressure-sensitive resistor 45, and a second wiring pattern 61 connected to the second contact pattern 51 is drawn out on the substrate 10. In the following description, "above" refers to the direction of looking at the surface side on which the first contact pattern 21 and the like are formed from the substrate 10, and "below" refers to the opposite direction, but this is not intended to limit the direction when using the pressure sensor 1.

[0014] Next, the configuration of the pressure sensor 1 will be described together with its manufacturing method. FIGS. 3-1 and 3-2 are explanatory diagrams of the manufacturing method of the pressure sensor 1. First, the substrate 10 shown in FIG. 3-1(a) is prepared. The substrate 10 is composed of a flexible synthetic resin film, and in this example, a polyethylene terephthalate (PET) film is used.

[0015] Next, as shown in FIG. 3-1(a), a first contact pattern 21 and a first wiring pattern 31 are simultaneously formed on the substrate 10 by screen printing a conductive paste (silver paste in this example). The first contact pattern 21 is circular in this example (it may have various other shapes), and a linear (it may have various other shapes) first wiring pattern 31 is formed so as to connect to a part of the outer periphery thereof.

[0016] Next, as shown in FIG. 3-1(b), a first pressure-sensitive resistor 41 whose resistance value changes according to pressure is formed by screen printing a carbon paste so as to cover the upper surface of the first contact pattern 21 and a part of the first wiring pattern 31 connected thereto. The first pressure-sensitive resistor 41 is circular in this example (it may have various other shapes), and its outer shape (outer diameter) dimension is formed larger than the outer shape (outer diameter) dimension of the first contact pattern 21. Therefore, the entire outer periphery of the first contact pattern 21 is covered by the first pressure-sensitive resistor 41. The carbon paste is composed of a conductive paint obtained by mixing a synthetic resin having flexibility even after curing, carbon powder, and a solvent.

[0017] Next, as shown in FIG. 3-1(c), a first conductive layer 81 is formed on the first pressure-sensitive resistor 41 by screen printing a silver paste. The first conductive layer 81 is circular in this example (it may have various other shapes), and is formed in the central portion of the first pressure-sensitive resistor 41. The outer shape (outer diameter) dimension of the first conductive layer 81 is formed smaller than the outer shape (outer diameter) dimensions of the first contact pattern 21 and the first pressure-sensitive resistor 41.

[0018] Next, as shown in FIG. 3-2(d), an insulating layer 71 having an opening 73 for exposing at least a part of the first pressure-sensitive resistor 41 is formed by screen-printing a resin paste. In this example, the insulating layer 71 is circular (it may have various other shapes), and a circular (it may have various other shapes) opening 73 is provided at its center. The outer shape (outer diameter) dimension of the insulating layer 71 is formed to be larger than the outer shape (outer diameter) dimensions of the first contact pattern 21 and the first pressure-sensitive resistor 41, and the inner circumference (inner diameter) dimension of the opening 73 is formed to be smaller than the outer shape (outer diameter) dimension of the first conductive layer 81. Therefore, the entire outer circumference of the first pressure-sensitive resistor 41 is covered by the insulating layer 71, and the entire first conductive layer 81 is exposed inside the opening 73.

[0019] Next, as shown in FIG. 3-2(e), a second conductive layer 85 is formed by screen-printing a silver paste on the insulating layer 71 including the opening 73. In this example, the second conductive layer 85 is circular (it may have various other shapes), and is formed in the central portion so as to cover the opening 73 of the insulating layer 71. The second conductive layer 85 is formed to have the same outer diameter dimension as the first conductive layer 81, whereby the entire opening 73 of the insulating layer 71 is covered by the second conductive layer 85. At this time, the second conductive layer 85 is filled inside the opening 73 of the insulating layer 71 and is formed so as to cover at least a part of the surface of the surrounding insulating layer 71 from the opening 73. Note that the outer shape (outer diameter) of the second conductive layer 85 may be different from the outer shape (outer diameter) of the first conductive layer 81.

[0020] Next, as shown in FIG. 3-2(f), a second pressure-sensitive resistor 45 whose resistance value changes according to pressure is formed on the insulating layer 71 including the second conductive layer 85 by screen printing a carbon paste. Similar to the first pressure-sensitive resistor 41, the second pressure-sensitive resistor 45 is circular in this example (it may have various other shapes), and its outer shape (outer diameter) dimensions are formed to be the same as those of the first pressure-sensitive resistor 41. Therefore, the entire upper surface and side surface of the second conductive layer 85 are covered by the second pressure-sensitive resistor 45. Similar to the first pressure-sensitive resistor 41, the carbon paste is composed of a conductive paint in which a synthetic resin having flexibility even after curing, carbon powder, and a solvent are mixed. The thickness of the second pressure-sensitive resistor 41 is formed to be the same as the thickness of the first pressure-sensitive resistor 41. Note that the outer shape (outer diameter) and thickness of the second pressure-sensitive resistor 45 may be different from the outer shape (outer diameter) and thickness of the first pressure-sensitive resistor 41.

[0021] Next, as shown in FIG. 2, a second contact pattern 51 and a second wiring pattern 61 are simultaneously formed on the substrate 10 including the upper surface of the second pressure-sensitive resistor 45 by screen printing a silver paste. The second contact pattern 51 is circular in this example (it may have various other shapes), and a linear (it may have various other shapes) second wiring pattern 61 is formed so as to connect to a part of the outer periphery thereof. The second contact pattern 51 is formed at a position facing the first contact pattern 21 with an area smaller than that of the first contact pattern 21. Also, the outer diameter dimension of the second contact pattern 51 is formed with an area larger than the outer diameter dimension of the second conductive layer 85. The second wiring pattern 61 is formed so as to contact from the upper surface of the second pressure-sensitive resistor 45 to the side surface of the second pressure-sensitive resistor 45, and further contact from the upper surface of the insulating layer 71 to the side surface of the insulating layer 71 and be drawn out onto the substrate 10.

[0022] The pressure sensor 1 is completed by the above manufacturing method. Needless to say, the above manufacturing procedure is an example, and it may be manufactured using various other different manufacturing procedures.

[0023] The pressure-sensitive sensor 1 configured as described above has the first pressure-sensitive resistor 41 interposed between the first contact pattern 21 and the first and second conductive layers 81 and 85, and the second pressure-sensitive resistor 45 interposed between the first and second conductive layers 81 and 85 and the second contact pattern 51, thereby generating a predetermined resistance value between the first and second contact patterns 21 and 51. Note that at least a part of the first contact pattern 21 is not in electrical connection with the other part unless it is located directly below the first conductive layer 81. Therefore, as shown in this embodiment, both are arranged in positions directly facing each other. Similarly, at least a part of the second contact pattern 51 is not in electrical connection with the other part unless it is located directly above the second conductive layer 85. Therefore, as shown in this embodiment, both are arranged in positions directly facing each other.

[0024] Then, when the substrate 10 is placed on a base (not shown) and the second contact pattern 51 is pressed from above by a pressing body such as a finger or a key top, both the first and second pressure-sensitive resistors 41 and 45 having flexibility are compressed, their thicknesses are reduced, and the carbon powders in the first and second pressure-sensitive resistors 41 and 45 come into strong contact with each other, thereby increasing the contact area between the carbon particles. As a result, the resistance value between the first and second contact patterns 21 and 51 becomes smaller. On the other hand, when the pressing is released, the thicknesses of the first and second pressure-sensitive resistors 41 and 45 return to their original thicknesses due to their elastic restoring forces, and the resistance value increases. That is, the resistance value between the first and second contact patterns 21 and 51 varies according to the magnitude of the pressing force (pressing pressure), and thus different outputs corresponding to the pressing pressure can be obtained, and the magnitude of the pressing pressure can be detected.

[0025] At this time, since no space is provided by a spacer between the first contact pattern 21 and the second contact pattern 51 as in the prior art, a change in the resistance value starts with the application of a light force. Therefore, it is suitable for use as the pressure-sensitive sensor 1 that requires the characteristic that the change in the resistance value starts with a light force and further changes as the pressing pressure increases.

[0026] Also, since the pressure sensor 1 is formed by laminating the first and second pressure-sensitive resistors 41 and 45 in two layers and the insulating layer 71 is also laminated, these first and second pressure-sensitive resistors 41 and 45 and the insulating layer 71 serve as a cushion, and when the pressure sensor 1 is pressed, it can have more rubber-like elasticity. As a result, the change in the resistance value becomes more linear corresponding to the strength of the pressing force, and the resolution of the output value according to the pressing force can be improved.

[0027] FIG. 4 is a diagram showing a current path when a voltage is applied between the first and second contact patterns 21 and 51. As shown in the figure, the current flows through the path of the first wiring pattern 31 ⇔ the first contact pattern 21 ⇔ the first pressure-sensitive resistor 41 ⇔ the first conductive layer 81 ⇔ the second conductive layer 85 ⇔ the second pressure-sensitive resistor 45 ⇔ the second contact pattern 51 ⇔ the second wiring pattern 61.

[0028] At this time, since the thickness of the first pressure-sensitive resistor 41 is thin, the current flows between the first contact pattern 21 to which the voltage is applied and the first conductive layer 81 only in the portion X1 of the surface that is perpendicular to the first conductive layer 81 in the entire first pressure-sensitive resistor 41. Similarly, since the thickness of the second pressure-sensitive resistor 45 is thin, the current flows between the second conductive layer 85 to which the voltage is applied and the second contact pattern 51 only in the portion X2 of the surface that is perpendicular to the second conductive layer 85 in the entire second pressure-sensitive resistor 45. That is, assuming that the resistance values of the first and second wiring patterns 31 and 61, the first and second contact patterns 21 and 51, and the first and second conductive layers 81 and 85 are zero, the resistance value between the first and second wiring patterns 31 and 61 is the resistance value only by the portion X1 of the first pressure-sensitive resistor 41 and the portion X2 of the second pressure-sensitive resistor 45.

[0029] That is, between the first and second contact patterns 21 and 51, conduction occurs only at the portion X1 where the first pressure-sensitive resistor 41 and the first conductive layer 81 face each other vertically, and the portion X2 where the second pressure-sensitive resistor 45 and the second conductive layer 85 face each other vertically (since a change in resistance value occurs). By adjusting the area and shape of the first and second conductive layers 81 and 85 (or in some cases, the first and second pressure-sensitive resistors 41 and 45), it becomes possible to easily and accurately adjust the resistance value (for example, reducing the area of the first and second conductive layers 81 and 85 increases the resistance value).

[0030] Incidentally, when the pressure sensor 1 is not being pressed, a larger resistance value is more preferable because the amount of change in the resistance value when it is pressed is greater, which improves the resolution of the output value according to the pressing force. In the pressure sensor 1, since the first pressure-sensitive resistor 41 and the second pressure-sensitive resistor 45 are connected in series, the total thickness of the first and second pressure-sensitive resistors 41 and 45 increases accordingly, and the resistance value when the first and second pressure-sensitive resistors 41 and 45 are not being pressed can be increased accordingly. From this aspect as well, a pressure sensor 1 with high resolution can be achieved.

[0031] Of course, in the pressure sensor 1, it is more preferable to increase the resistance value by forming the thicknesses of the first and second pressure-sensitive resistors 41 and 45 themselves to be thicker than the thicknesses of the first and second contact patterns 21 and 51, etc., but the present invention is not limited to this, and they may have the same or a thinner thickness as the thicknesses of the first and second contact patterns 21 and 51, etc.

[0032] The first and second conductive layers 81 and 85, like this pressure sensor 1, are preferably formed with their outer dimensions (outer diameters) larger than the inner diameter dimension of the opening 73 so as to surely block the entire inside of the opening 73 of the insulating layer 71 (considering printing misalignment, etc.). Here, the second conductive layer 85 formed later on the insulating layer 71 is preferably formed so as to be filled inside the opening 73 of the insulating layer 71 and cover at least a part of the surface of the surrounding insulating layer 71 from the opening 73.

[0033] FIG. 5 is a plan view showing a specific example of the pressure sensor 1. As shown in the figure, the substrate 10 includes a sensor body forming portion 11 and an output lead portion 13 that is connected to the outer periphery of the sensor body forming portion 11 and extends in a strip shape. The sensor body forming portion 11 is printed with the first and second contact patterns 21 and 51, the first and second pressure-sensitive resistors 41 and 45, the insulating layer 71, the first and second conductive layers 81 and 85, and a part of the first and second wiring patterns 31 and 61 respectively connected to the first and second contact patterns 21 and 51. The remaining portions of the first and second wiring patterns 31 and 61 are printed on the output lead portion 13, and output terminal patterns 33 and 63 are printed at their tips. Thus, a voltage can be easily applied between the first and second contact patterns 21 and 51, and an output can be obtained.

[0034] In the pressure sensor 1 described above, the second wiring pattern 61 is drawn out on the substrate 10 after contacting the upper surface and the side surface (outer peripheral surface) of the second pressure-sensitive resistor 45 and the upper surface and the side surface (outer peripheral surface) of the insulating layer 71. For example, a part of the outer periphery of the second contact pattern 51, a part of the outer periphery of the second pressure-sensitive resistor 45, and a part of the outer periphery of the insulating layer 71 are made to coincide, and the second wiring pattern 61 is connected at the coinciding part, so that the second wiring pattern 61 is brought into contact only with the side surface of the second pressure-sensitive resistor 45 and the side surface of the insulating layer 71 (without contacting the upper surfaces of the second pressure-sensitive resistor 45 and the insulating layer 71) and drawn out on the substrate 10. Also, if the outer shape of the second pressure-sensitive resistor 45 is made larger (or partially larger) than the outer shape of the insulating layer 71 to cover the insulating layer 71, the second wiring pattern 61 can be configured to be drawn out on the substrate 10 by contacting only the upper surface and the side surface (or side surface) of the second pressure-sensitive resistor 45 without contacting the insulating layer 71.

[0035] In the opening 73 of the insulating layer 71, since the first and second conductive layers 81 and 85 are arranged between the first pressure-sensitive resistor 41 and the second pressure-sensitive resistor 45, regardless of the area and shape of the opening 73 of the insulating layer 71, the area and shape of the first conductive layer 81 on the side facing the first contact pattern 21 and the area and shape of the second conductive layer 85 on the side facing the second contact pattern 51 can be freely adjusted, so that these resistance values can be easily adjusted.

[0036] In the above embodiment, two first and second conductive layers 81 and 85 are provided as the conductive layers, but the conductive layer may be constituted by only one of the conductive layers 81 or 85. However, it is preferable to provide both the first and second conductive layers 81 and 85 because, as described above, both the resistance value between the first pressure-sensitive resistor 41 and the resistance value between the second pressure-sensitive resistor 45 can be easily adjusted.

[0037] In the above embodiment, the second conductive layer 85 fills the entire opening 73 of the insulating layer 71. However, if electrical continuity between the first and second conductive layers 81 and 85 can be achieved, it is not necessarily required to fill the entire opening 73, and only a part may be filled.

[0038] As described above, the pressure sensor 1 forms a first contact pattern 21 and a first wiring pattern 31 connected to the first contact pattern 21 on the substrate 10, forms a first pressure-sensitive resistor 41 whose resistance value changes according to pressure on the first contact pattern 21, forms an insulating layer 71 having an opening 73 and conductive layers 81, 85 closing the opening 73 on the first pressure-sensitive resistor 41, forms a second pressure-sensitive resistor 45 whose resistance value changes according to pressure on the insulating layer 71 including the conductive layers 81, 85, forms a second contact pattern 51 at a position facing the first contact pattern 21 on the second pressure-sensitive resistor 45, and further forms a second wiring pattern 61 connected to the second contact pattern 51 on the substrate 10. Therefore, the pressure sensor 1 can be configured by forming various patterns on a single substrate 10. For this reason, the number of components can be reduced and the thickness can be made thinner, and there is no possibility of misalignment due to assembly between the first and second contact patterns 21, 51, the first and second pressure-sensitive resistors 41, 45, the conductive layers 81, 85, and the insulating layer 71.

[0039] Also, since the pressure sensor 1 forms the conductive layers 81, 85 so as to fill the inside of the opening 73 of the insulating layer 71 and cover at least a part of the surface of the surrounding insulating layer 71 from the opening 73, the entire inside of the opening 73 can be surely closed by the conductive layers 81, 85.

[0040] Also, since the second pressure-sensitive resistor 45 is formed so as to cover the upper surface and the side surface of the conductive layer 85, the second pressure-sensitive resistor 45 located directly above the entire upper surface of the conductive layer 85 (the portion of X2 in FIG. 4) can act as a resistor in the electric circuit.

[0041] Further, since the pressure sensor 1 is formed by laminating a first contact pattern 21, a first wiring pattern 31, a first pressure-sensitive resistor 41, an insulating layer 71, conductive layers 81 and 85, a second pressure-sensitive resistor 45, a second contact pattern 51, and a second wiring pattern 61 on a substrate 10 by printing, various patterns can be easily and accurately formed at their proper positions on a single substrate 10, thereby reducing the number of components, the manufacturing cost, and the thickness. Also, there is no longer any risk of misalignment due to assembly in the positions of the various patterns.

[0042] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the technical idea described in the claims, the specification, and the drawings. Even if there is no description in the specification and the drawings regarding any shape, structure, or material, as long as the functions and effects of the present invention are achieved, it is within the scope of the technical idea of the present invention. For example, it goes without saying that various changes can be made to the shapes and arrangement positions of the above substrate 10, first contact pattern 21, first wiring pattern 31, first pressure-sensitive resistor 41, insulating layer 71, opening 73, first and second conductive layers 81 and 85, second pressure-sensitive resistor 45, second contact pattern 51, and second wiring pattern 61.

[0043] Also, in the above example, screen printing was used to form the various patterns, but other various printing methods (e.g., offset printing, inkjet printing), or even various pattern formation methods other than printing (e.g., etching methods) may be used. Further, in the above embodiment, a flexible substrate was used as the substrate 10, but a rigid substrate may also be used. Also, an insulating layer or an insulating film may be separately provided on the second contact pattern 51 and configured to be pressed by a pressing body from above.

[0044] In addition, as long as there is no contradiction in the purpose, configuration, etc., the embodiments described above and shown in each figure can be combined with each other's description content. Also, the description content of the above description and each figure can be independent embodiments even if it is a part thereof, and the embodiments of the present invention are not limited to one embodiment combining the above description and each figure.

Explanation of Reference Numerals

[0045] 10 Substrate 21 First contact pattern 31 First wiring pattern 41 First pressure-sensitive resistor 45 Second pressure-sensitive resistor 51 Second contact pattern 61 Second wiring pattern 71 Insulating layer 73 Opening 81 First conductive layer (conductive layer) 85 Second conductive layer (conductive layer)

Claims

1. In a pressure-sensitive sensor whose resistance value changes according to the applied pressure, a first contact pattern and a first wiring pattern connected to the first contact pattern are formed on a substrate, a first pressure-sensitive resistor whose resistance value changes according to pressure is formed on the first contact pattern, an insulating layer having an opening and a conductive layer closing the opening are formed on the first pressure-sensitive resistor, a second pressure-sensitive resistor whose resistance value changes according to pressure is formed on the insulating layer including the conductive layer, a second contact pattern is formed at a position facing the first contact pattern on the second pressure-sensitive resistor, and a pressure-sensitive sensor, characterized in that a second wiring pattern connected to the second contact pattern is drawn out on the substrate.

2. The pressure-sensitive sensor according to Claim 1, wherein the conductive layer is filled inside the opening of the insulating layer and is formed so as to cover at least a part of the surface of the surrounding insulating layer from the opening, is characterized.

3. The pressure-sensitive sensor according to Claim 1 or 2, wherein the second pressure-sensitive resistor is formed so as to cover the upper surface and the side surface of the conductive layer, is characterized.

4. The pressure-sensitive sensor according to Claim 1 or 2 or 3, wherein the second wiring pattern is drawn out on the substrate in contact with the upper surface or the side surface of the second pressure-sensitive resistor and the upper surface or the side surface of the insulating layer, is characterized.

5. The pressure-sensitive sensor according to any one of Claims 1 to 4, wherein the first contact pattern, the first wiring pattern, the first pressure-sensitive resistor, the insulating layer, the conductive layer, the second pressure-sensitive resistor, and the second contact pattern and the second wiring pattern are laminated and formed by printing on the substrate, is characterized.

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