JP2013068563A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor 1 having good sensitivity without increasing an addition amount of conductive particles of a pressure-sensitive conductive sheet.SOLUTION: A pressure sensor 1 comprises: an insulating substrate 2; an organic transistor 10 provided on one principal surface of the insulating substrate 2; a voltage power supply 30 that applies a predetermined voltage to a source electrode 12 of the organic transistor 10; a pressure-sensitive conductive body 20 that is provided between the voltage power supply 30 and the source electrode 12 and is connected in series with the source electrode 12; and a pressing sheet 60 laminated on one principal surface side of the pressure-sensitive conductive body. The pressure-sensitive conductive body 20 and the pressing sheet 60 have at least portions (recess parts 62) that are in noncontact with each other, and the other portions (protrusion parts 61) that are in contact with each other.

Description

  The present invention relates to a flexible pressure sensor.

  With regard to this type of technology, a flexible detection device is known in which a pressure-sensitive conductive rubber sheet on which an electrode is formed is bonded to the main surface of a polymer film on which an organic transistor is formed (Patent Document 1).

JP-A-2005-150146

  In general, a material in which graphite is added to silicone rubber is used as a pressure-sensitive conductive sheet constituting a pressure sensor in combination with an organic transistor. When this pressure-sensitive conductive sheet is pressed and compressed, graphite, which is a conductive material, comes into contact with each other, a conductive path is formed and the resistance value decreases, so that the potential difference between the source and drain of the organic transistor can be changed. Since this is possible, it is possible to detect a change in pressure according to the fluctuation of the potential difference.

  Since graphite contained as a conductive substance in this pressure-sensitive conductive sheet is a brittle material, it is desirable to reduce the amount of graphite contained in the pressure-sensitive conductive sheet from the viewpoint of improving the durability of the pressure sensor.

  However, if the amount of graphite contained in the pressure-sensitive conductive sheet is reduced, the rate of change of the resistance value of the pressure-sensitive conductive sheet is reduced, and there is a problem that the sensitivity is insufficient in a low pressure region.

  The problem to be solved by the present invention is to provide a pressure sensor with good sensitivity even in a low pressure region without increasing the amount of graphite contained in the pressure-sensitive conductive sheet.

  [1] The present invention relates to an insulating substrate, an organic transistor provided in a matrix on one main surface of the insulating substrate, a voltage power source that applies a predetermined voltage to a source electrode of the organic transistor, A pressure-sensitive conductor disposed between a voltage power source and the source electrode and connected in series with the source electrode; and a pressure sheet laminated on one main surface side of the pressure-sensitive conductor, and The above-mentioned problem is solved by providing a pressure sensor characterized in that at least a part of the pressure-sensitive conductor and the pressing sheet is non-contact.

  [2] On the surface of the pressure sheet of the invention, which is laminated on the pressure-sensitive conductor, a convex portion that contacts the pressure-sensitive conductor can be provided, and a non-contact concave portion can be provided on the pressure-sensitive conductor. .

  [3] An electrode can be formed on the top of the convex portion of the pressure sheet of the invention.

  [4] The convex portion of the pressure sheet of the invention can be formed of a conductive material.

  [5] The pressure-sensitive conductor of the present invention is composed of a pressure-sensitive conductive sheet in which conductive particles are added to an elastic material, and a convex portion in contact with the pressure sheet on one main surface side where the pressure sheet is laminated; A non-contact recess can be formed in the pressing sheet.

  According to the present invention, since at least a part of the joint surface between the pressure-sensitive conductor and the pressing sheet is made non-contact, the pressing force received at the non-contact portion acts on the contact portion. The amount of deformation of the pressing sheet can be increased by concentrating the pressing force on the contact portion. For this reason, the sensitivity in a low pressure region can be improved without increasing the amount of graphite contained in the pressure-sensitive conductive sheet. As a result, it is possible to provide a pressure sensor with high durability and reliability by improving sensitivity in a low pressure region while preventing embrittlement due to an increase in the amount of graphite added.

It is a circuit diagram of a unit composition of a pressure sensor concerning an embodiment of the present invention. It is sectional drawing of the unit structure of the pressure sensor which concerns on embodiment of this invention. It is sectional drawing of the touchscreen display which has arrange | positioned the pressure sensor which concerns on embodiment of this invention in matrix form. It is a graph which shows an example of the pressure resistance characteristic of the pressure-sensitive conductive sheet of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is process sectional drawing for demonstrating an example of the manufacturing method of the pressure sensor which concerns on embodiment of this invention. It is the elements on larger scale corresponding to the A field shown in Drawing 2 concerning other modes of a press sheet. It is the elements on larger scale corresponding to the A field shown in Drawing 2 concerning the other mode of a press sheet.

<First Embodiment>
Hereinafter, a pressure sensor according to a first embodiment of the present invention will be described with reference to the drawings. In the first embodiment of the present invention, an example will be described in which the pressure sensors according to the present invention are arranged in a matrix and applied to a touch panel type input device.

  1 and 2 are diagrams showing a configuration of an example of a pressure sensor 1 according to this embodiment of the present invention. In the present embodiment, the pressure sensors 1 shown in FIGS. 1 and 2 are arranged in a matrix along a predetermined operation surface to constitute a touch panel display. In addition, the use of the pressure sensor 1 of this embodiment is not limited to a touch panel display, but can be applied to a fingerprint sensor, a switch, or the like.

As shown in FIG. 1, the pressure sensor 1 of this embodiment includes an organic transistor 10, a pressure-sensitive conductor 20, and a voltage power supply 30. The organic transistor 10 is a transistor using the organic semiconductor layer 15 and includes a gate electrode 11, a source electrode 12, and a drain electrode 13. The voltage power supply 30 applies a predetermined voltage V _DD to the source electrode 12 of the organic transistor 10. The organic transistor 10 outputs a signal corresponding to the current value between the source and the drain when the predetermined voltage V _DD is applied to the external signal processing device 40. The signal processing device 40 detects the pressing position or the pressing force based on the signal acquired from the organic transistor 10.

  FIG. 1 shows a circuit diagram of a pressure sensor 1 in which an organic transistor (FET) 10 and a pressure sensitive conductor 20 are combined. In the pressure sensor 1 of the present embodiment, the pressure-sensitive conductor 20 is provided between the voltage power supply 30 and the organic transistor 10, and the source electrode 12 of the organic transistor 10 and the pressure-sensitive conductor 20 are connected in series. It has a structure.

When the organic transistor 10 is the voltage of the word line (WL) to turn on state (V _WL) to set the power voltage V _DD, in the linear region of the output characteristics of the organic transistor 10, the source - the amount of current flowing between the drain It changes in proportion to the potential difference between the source and drain. Further, the potential difference between the source and drain when a constant voltage is applied by the voltage power supply 30 depends on the resistance value of the pressure-sensitive conductor 20 connected in series with the source electrode 12.

  The pressure-sensitive conductor 20 functions as a variable resistance member whose resistance value changes according to the pressure received by pressing. The pressure-sensitive conductor 20 of the present embodiment is made of a material in which conductor particles are dispersed in an elastic polymer rubber or the like, and has a characteristic that the resistance value decreases when pressed. Although not particularly limited, as the pressure-sensitive conductive sheet 21 of the present embodiment, for example, a pressure-sensitive conductive rubber sheet formed by adding graphite to silicone rubber can be used. The pressure-sensitive conductive sheet 21 is based on the principle that when a silicone rubber is compressed by applying pressure, graphite as a conductive material comes into contact with each other, a conductive path is formed, and a resistance value decreases. That is, when the pressure-sensitive conductor 20 is pressed and pressure is applied, the resistance value of the pressure-sensitive conductor 20 decreases due to this pressure application, and therefore the potential difference between the source and the drain increases and the amount of current flowing increases. If the pressing force applied to the pressure-sensitive conductor 20 and the amount of current are acquired in advance, the amount of pressure (pressing force) applied to the pressure sensor 1 is detected by reading the change in signal corresponding to the amount of current. Can do.

  FIG. 2 is a cross-sectional view of the pressure sensor 1 of the present embodiment having the circuit shown in FIG. As shown in FIG. 2, the gate electrode 11, the source electrode 12, and the drain electrode 13 constituting the organic transistor 10 are formed on one main surface of the insulating substrate 2 and covered with the gate insulating layer 14. An organic semiconductor layer 15 is formed above (upward in the drawing along the stacking direction, hereinafter the same). A pressure sensitive conductor 20 is formed on the organic semiconductor layer 15 via an insulating layer 17. Furthermore, the upper surface of the pressure-sensitive conductor 20 (the upper surface in the drawing along the stacking direction, the same applies hereinafter) is covered with the pressing sheet 60. In the pressure sensor 1 shown in FIG. 2, when the upper surface P of the pressing sheet 60 is pressed, the organic transistor 10 outputs a signal corresponding to the pressing force.

  As shown in FIG. 2, the pressure-sensitive conductor 20 is connected in series with the source electrode 12 via the first pad electrodes 18 and 18a. The pressure-sensitive conductor 20 may be constituted by a single pressure-sensitive conductive sheet 21 or may be constituted by laminating a plurality of pressure-sensitive conductive sheets. Further, as shown in the figure, the second pad electrode 19 is formed on the upper surface of the pressure-sensitive conductive sheet 21 laminated on the upper side of the pressure-sensitive conductor 20 (boundary surface with the pressing sheet 60). The second pad electrode 19 is connected to the voltage power supply 30. The second pad electrode 19 and the first pad electrode 18 connected to the voltage power supply 30 are electrically connected through the pressure-sensitive conductor 20 (21) when a voltage is applied.

  As shown in FIG. 2, the pressure sensor 1 of the present embodiment includes a pressing sheet 60 laminated on one main surface side (surface P side that receives a pressing operation) of the pressure-sensitive conductor 20. Since the pressing sheet 60 is laminated on the pressure-sensitive conductive sheet 21, the pressing sheet 60 and the pressure-sensitive conductive sheet 21 are in contact with each other, but at least a part thereof is not in contact. By forming a non-contact portion in this way, the contact area between the stacked pressure sheet 60 and the pressure-sensitive conductive sheet 21 is larger than the area where the pressure sheet 60 and the pressure-sensitive conductive sheet 21 face (overlap). Can be small.

  In the present embodiment, by reducing the contact area between the pressure sheet 60 and the pressure-sensitive conductive sheet 21, stress is concentrated on the contact portion between the pressure sheet 60 and the pressure-sensitive conductive sheet 21 when pressure is applied. Even when the pressure sensitive conductive sheet 21 with a small amount of addition is used, the sensitivity in the low pressure region can be prevented from being lowered. Since the sensitivity in the low pressure region can be maintained without increasing the amount of graphite added, a highly durable pressure sensitive conductive sheet can be used.

  Although not particularly limited, in the present embodiment, the pressure sensitive conductive sheet 21 and the pressure sheet 60 are provided by providing the convex portion 61 and the concave portion 62 on the main surface of the pressure sheet 60 on the side that is laminated on the pressure sensitive conductive sheet 21. A part of is not contacted. That is, the concave portion 62 is not in contact with the pressure-sensitive conductive sheet 21 while the convex portion 61 of the pressing sheet 60 is in contact with the pressure-sensitive conductive sheet 21. Although the formation method of the convex part 61 and the recessed part 62 is not specifically limited, For example, it can form by the thermal imprint method using the uneven | corrugated type | mold corresponding to the shape of the convex part 61 and the recessed part 62. FIG.

  Moreover, in this embodiment, it is preferable that the position which provides the convex part 61 is a position facing the 1st pad electrode 18 connected with the source electrode 12 of an organic transistor. Moreover, as shown in FIG. 2, the 2nd pad electrode 19 is formed in the top part of the convex part 61 of the press sheet 60 of this embodiment. That is, as shown in the figure, the second pad electrode 19 provided on the top of the convex portion 61 of the pressing sheet 60 is connected to the first pad electrode 18 connected to the organic transistor 10 via the pressure-sensitive conductive sheet 21. It is arranged at the opposite position.

  FIG. 3 is a cross-sectional view of the touch panel display 100 in which the unit configuration of the pressure sensor 1 shown in FIG. 2 is arranged in a matrix, and shows a state in which the operation surface of the touch panel display 100 is pressed in the direction of arrow F with a finger. It is. In addition, the area | region shown by X of FIG. 3 is equivalent to the unit structure of the pressure sensor 1 shown in FIG.

  When the pressing sheet 60 is pressed along the direction of the arrow F from the operation surface side of the touch panel display 100, the pressing force applied to the pressing sheet 60 is not transmitted to the concave portion 62 but concentrated on the convex portion 61, and the convex portion 61 The second pad electrode 19 provided on the top of the substrate strongly presses the first pad electrode 18. On the other hand, when the pressing sheet 60 and the pressure-sensitive conductive sheet 21 are in contact with each other (there is no non-contact portion), the pressing force applied to the pressing sheet 60 is applied to the entire contact surface around the pressing portion. Expected to be dispersed.

  Accordingly, when the same pressing force is applied to the pressing sheet 60, the pressure-sensitive conductive sheet 21 and the pressing sheet 60 are provided with a convex portion 61 that contacts the non-contact concave portion 62. This embodiment has a stronger pressure (unit area). The pressure-sensitive conductive sheet 21 can be pressed with a pressing force. That is, when the same pressing force is applied to the pressing sheet 60, the pressing sheet 60 and the pressure-sensitive conductive sheet 21 are provided over the entire surface in the present embodiment in which the concave portion 62 (non-contact portion) and the convex portion 61 are provided. The pressure-sensitive conductive sheet 21 can be greatly deformed (compressed) as compared with the case where it is in contact (no contact portion).

  Incidentally, as shown in FIG. 4, the pressure-sensitive conductive sheet 21 has a pressure resistance characteristic in which a resistance value changes with respect to a given pressure. The pressure resistance characteristics of the pressure-sensitive conductive sheet 21 vary depending on the properties of the material, the hardness, the content of conductive particles, and the like. FIG. 4 shows the pressure resistance characteristics of the pressure-sensitive conductive sheets 21A and 21B.

  For this reason, when the same pressing force is applied, the pressure sensor 1 of the present embodiment including the pressure-sensitive conductive sheet 21 and the pressing sheet 60 provided with the convex portion 61 that comes into contact with the non-contact concave portion 62 includes the pressing sheet 60. And the pressure-sensitive conductive sheet 21 are greatly reduced in resistance than the pressure sensor in a mode in which the pressure-sensitive conductive sheet 21 is in contact with the entire surface without a gap (there is no non-contact portion). In addition, the potential difference between the source and drain of the organic transistor 10 can be increased, and the amount of change in the amount of current flowing between the source and drain can be increased.

  As a result, it is possible to provide the pressure sensor 1 having good responsiveness to the same pressing force. In other words, the pressure sensor 1 with high accuracy can be provided even with a low pressing force.

  Hereinafter, based on FIGS. 5-11, the manufacturing method of the pressure sensor 1 of this embodiment is demonstrated.

  First, as shown in FIG. 5, the gate electrode 11 is formed on one main surface of the insulating substrate 2. As the insulating substrate 2, polymer films such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and polyimide can be used. The formation method of the gate electrode 11 is not particularly limited, and the gate electrode 11 is formed by a printing technique such as an inkjet method or a gravure offset method, or a formation method such as vacuum deposition or a sputtering method. Examples of the material for the gate electrode 11 include metal nanoparticle inks such as Ag and Cu, and conductive polymers such as PEDOT (poly (3,4-ethylenedioxythiophene)) / PSS (polystyrene sulfonic acid). A metal material such as Au or Al can be used. After the gate electrode 11 is formed, baking is performed in an oven or the like as necessary.

  Next, as illustrated in FIG. 6, an insulating layer 16 that functions as a bank (weir) is formed around the gate electrode 11 using a resin material such as an epoxy resin by a method such as screen printing. After forming the insulating layer 16, it is dried in an oven or the like as necessary. Note that the insulating layer 16 of this example is not necessarily required, and may be formed according to a later process or a material used in a later process. Subsequently, the gate insulating film 14 is formed so as to cover the gate electrode 11 using a resin material such as a polyimide resin, for example, using a printing technique such as an inkjet method. After the insulating film 14 is formed, the insulating film 14 is heated in an oven or the like as necessary, and dried or crosslinked.

  Next, as shown in FIG. 7, the source electrode 12 and the drain electrode 13 are formed. The formation method of the source electrode 12 and the drain electrode 13 is not particularly limited, and the source electrode 12 and the drain electrode 13 are formed by a printing technique such as an ink jet method or a gravure offset method, or a formation method such as vacuum deposition or a sputtering method. As a material of the source electrode 12 and the drain electrode 13, for example, a metal nanoparticle ink such as Ag or Cu, a conductive polymer such as PEDOT / PSS, or a metal material such as Au or Al can be used. After the source electrode 12 and the drain electrode 13 are formed, baking is performed in an oven or the like as necessary.

  Next, as shown in FIG. 8, the organic semiconductor layer 15 is formed. The method for forming the organic semiconductor layer 15 is not particularly limited, and for example, a printing technique such as an ink jet method or a flexographic printing method, or a film forming method such as vacuum evaporation can be used. In addition to pentacene, organic semiconductor materials include acenes such as anthracene, tetracene, and hexacene; One or more hydrogen-based materials can be used in combination. In addition, poly (3-alkylthiophene), poly (3-hexylthiophene), poly (3-octylthiophene), poly (2,5-thienylenevinylene), poly (para-phenylenevinylene), poly (9,9 -Dioctylfluorene), poly (9,9-dioctylfluorene-co-bis-N, N '-(4-methoxyphenyl) -bis-N, N'-phenyl-1,4-phenylenediamine), poly (9 , 9-dioctylfluorene-co-benzothiadiazole) or other organic semiconductor materials known at the time of filing can be used.

  Moreover, the formation method of the organic-semiconductor layer 15 is also not specifically limited, Printing techniques, such as an inkjet method and a flexographic printing method, methods, such as a vacuum evaporation method and a spray method, can be used.

  In this embodiment, since the pressure sensor 1 is produced using the organic semiconductor layer 15, it can be manufactured by a low temperature process. In addition, since a plastic substrate can be used, an element that is flexible and lightweight and is not easily broken can be provided. In addition, since the organic transistor 10 can be formed by a printing method, the manufacturing process can be greatly simplified as compared with the photolithography method for manufacturing the inorganic semiconductor layer, and the material used during the manufacturing is also greatly reduced. can do. For this reason, while reducing the environmental load at the time of manufacture, manufacturing cost can be suppressed.

Next, as shown in FIG. 9, an insulating layer 17 that covers the organic semiconductor layer 15 is formed. The material of the insulating layer 17 is not particularly limited, and for example, an insulating material such as parylene (paraxylylene polymer) can be used. Further, the method for forming the insulating layer 17 is not particularly limited, and the insulating layer 17 can be formed by a forming method such as a vapor deposition method. Further, as shown in the figure, the insulating layer 17 is formed with a via hole 18a ′ for a via 18a that constitutes a part of the first pad electrode 18 that is electrically connected to the source electrode 12 in the product. A method for forming the via hole 18a ′ is not particularly limited. In this example, the via hole 18a ′ is formed by drilling with a CO ₂ laser.

  Next, as shown in FIG. 10, the via hole 18 a ′ formed in the previous step is filled with a conductive material to form a first pad electrode 18 that is electrically connected to the source electrode 12. The conductive material used for forming the first pad electrode 18 is not particularly limited, but a metal material such as Au or Ag, or a conductive paste containing these materials can be used. The formation method of the first pad electrode 18 is not particularly limited, and a printing technique such as an ink jet method, and a film formation method such as a vacuum evaporation method or a sputtering method can be used. Further, an insulating layer 17 in which a first pad electrode 18 including a via 18a and an electrode 18 is formed in advance is prepared, and this insulating layer 17 is laminated on a semi-finished product on which the organic semiconductor layer 15 shown in FIG. 8 is formed. By doing so, the semi-finished product shown in FIG. 10 can be obtained.

  Next, a pressure-sensitive conductive sheet 21 having a desired pressure resistance (P-R) characteristic is laminated on the insulating layer 17 so as to be in contact with the first pad electrode 18 as shown in FIG. In this example, an example in which one pressure-sensitive conductive sheet 21 is laminated is shown, but a plurality of pressure-sensitive conductive sheets 21 can be laminated as necessary.

  Finally, the pressing sheet 60 made of a polymer film such as PET or PEN on which the second pad electrode 19 is formed is laminated on the pressure-sensitive conductive sheet 21 to perform the present embodiment shown in FIG. The pressure sensor 1 having the form can be manufactured. As described above, a non-contact portion is formed on the surface of the pressing sheet 60 that is in contact with the pressure-sensitive conductive sheet 21. The material of the 2nd pad electrode 19 is not specifically limited, For example, electroconductive materials, such as Au and Cu, can be used.

  In addition, the material and manufacturing method for manufacturing the organic transistor 10 are not limited to the above, The material and manufacturing method known at the time of application can be applied suitably.

  In the present specification and drawings, for convenience of explanation, one unit of the pressure sensor 1 will be described as an example. In this embodiment, a plurality of pressure sensors 1 shown in FIG. The touch panel display 100 according to the present embodiment can be configured by arranging the planar pressure sensor 1 in a matrix on a parallel plane). By producing the planar pressure sensor 1 in this way, it is possible to detect the distribution signal of the pressing force on the operation surface based on the detection result of each organic transistor 10 similarly arranged in a matrix. In addition, by acquiring in advance a current change between the source electrode 12 and the drain electrode 13 with respect to a predetermined pressing force, the magnitude of the pressing force when the pressure sensor 1 is pressed can also be detected. .

  As described above, according to the pressure sensor 1 in which the organic transistor 10 and the pressure-sensitive conductor 20 according to the present embodiment are combined in the present invention, the pressure sheet 60 and the pressure-sensitive conductor 20 (pressure-sensitive conductive sheet) to be pressed are operated. 21) Since the pressing force can be concentrated on the contact part (convex part 61) other than the non-contact part (concave part 62) by making at least a part of the pressure sensitive conductive sheet 21 included in the pressure-sensitive conductive sheet 21 The sensitivity in the low pressure region can be improved without increasing the amount of graphite produced. As a result, it is possible to provide a pressure sensor 1 (touch panel display 100) with high durability and reliability by improving sensitivity in a low pressure region while preventing embrittlement due to an increase in the amount of graphite added. .

Second Embodiment
Hereinafter, a pressure sensor 1 according to a second embodiment of the present invention will be described with reference to FIG. The pressure sensor 1 of the present embodiment is characterized by the configuration of the convex portion 61 of the pressing sheet 60. Here, it demonstrates centering around a different point and the description regarding 1st Embodiment is used about another part. FIG. 12 is a partially enlarged view of a portion corresponding to area A shown in FIG. The convex portion 61 of the pressing sheet 60 of the present embodiment is formed of a conductive material. Although not particularly limited, the conductive protrusion 61 can be formed by a printing technique such as screen printing using a conductive paste. According to this embodiment, while having the same effect as 1st Embodiment, it is not necessary to form uneven | corrugated shape in the press sheet 60, Therefore A manufacturing cost can be reduced.

<Third Embodiment>
Hereinafter, a pressure sensor 1 according to a third embodiment of the present invention will be described with reference to FIG. The pressure sensor 1 of the present embodiment is characterized in that unevenness is formed on the pressure-sensitive conductive sheet 21 (pressure-sensitive conductor 20) instead of the pressing sheet 60. Here, it demonstrates centering around a different point and the description regarding 1st Embodiment is used about another part. FIG. 13 is a partial enlarged view of a portion corresponding to area A shown in FIG. In the present embodiment, a convex portion 21a that is in contact with the pressing sheet 60 and a concave portion 21b that is not in contact with the pressing sheet 60 are provided on one main surface side where the pressing sheet 60 of the pressure-sensitive conductive sheet 21 (pressure-sensitive conductor 20) is laminated. Form. Although not particularly limited, the convex portion 21a and the concave portion 21b of the pressure-sensitive conductive sheet 21 (pressure-sensitive conductor 20) can be formed by a thermal imprint method or the like. According to this embodiment, the same operational effects as those of the first embodiment can be achieved.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Touch-panel display 1 ... Pressure sensor 2 ... Insulating base material 10 ... Organic transistor 11 ... Gate electrode 12 ... Source electrode 13 ... Drain electrode 14 ... Gate insulating layer 15 ... Organic-semiconductor layer 16, 17 ... Insulating layer 18, 18a ... First pad electrode (18 ... electrode, 18a ... via)
18a '... via hole 19 ... second pad electrode 20 ... pressure sensitive conductor 21, 21A, 21B ... pressure sensitive conductive sheet 21a ... convex part, 21b ... concave 30 ... voltage power supply 40 ... signal processing device 60 ... pressing sheet 61 ... convex Part 62 ... concave part

Claims (5)

An insulating substrate;
An organic transistor provided in a matrix on one main surface of the insulating substrate;
A voltage power supply for applying a predetermined voltage to the source electrode of the organic transistor;
A pressure sensitive conductor disposed between the voltage source and the source electrode and connected in series with the source electrode;
A pressure sheet laminated on one main surface side of the pressure-sensitive conductor, and
The pressure sensor, wherein the pressure-sensitive conductor and the pressing sheet are at least partially non-contact.   The pressure sheet has a convex portion that contacts the pressure sensitive conductor and a concave portion that is not in contact with the pressure sensitive conductor on a surface laminated on the pressure sensitive conductor. The pressure sensor described in 1.   The pressure sensor according to claim 2, wherein an electrode is formed on the top of the convex portion of the pressing sheet.   The pressure sensor according to claim 2, wherein the convex portion of the pressing sheet is formed of a conductive material.   The pressure-sensitive conductor is a pressure-sensitive conductive sheet obtained by adding conductive particles to an elastic material. The pressure-sensitive conductor is formed on one main surface side on which the pressure sheet is laminated, and has a convex portion that is in contact with the pressure sheet and the pressure sheet. The pressure sensor according to claim 1, further comprising a contact recess.

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