CAPACITIVE SENSOR, SENSOR SHEET, AND METHOD FOR MANUFACTURING CAPACITIVE SENSOR

• US 20170315165A1
• Filed: 07/18/2017
• Published: 11/02/2017
• Est. Priority Date: 07/31/2015
• Status: Active Grant

• Current Assignee: Sumitomo Riko Company Limited.
• Original Assignee: Sumitomo Riko Company Limited.
• Inventors: KAWAGUCHI, Junya, FUJIKAWA, Tomohiro, TAGUCHI, Yutaro, YAMADA, Hiroshi
• Granted Patent: US 10,317,442 B2
• Time in Patent Office: Days
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01L 1/14 by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 5/00 Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
• CPC Class Codes: G01L 5/0014 by using capacitive sensors
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

Provided is a flexible, durable capacitive sensor that achieves high flexibility in designing wiring arrangement. A capacitive sensor includes a dielectric layer and a plurality of electrode units placed on both sides of the dielectric layer in the front-back direction. The electrode unit includes an insulating layer having through holes extending therethrough in the front-rear direction, electrode layers placed on one side of the insulating layer in the front-back direction, and jumper wiring layers placed on the other side of the insulating layer in the front-back direction and electrically connected to the electrode layers through the through holes. The insulating layer has an elongation at break of 60% or more, a tension set of less than 5%, and a volume resistivity of 1.0×10¹⁰ Ω·cm or more.

Claims

1. A capacitive sensor comprising:

a dielectric layer; and

a plurality of electrode units placed on both sides of the dielectric layer in a front-back direction, wherein the electrode unit includes an insulating layer having a through hole extending therethrough in the front-back direction, an electrode layer placed on one side of the insulating layer in the front-back direction, and a jumper wiring layer placed on the other side of the insulating layer in the front-back direction and electrically connected to the electrode layer through the through hole, and

the insulating layer has an elongation at break of 60% or more and a tension set of less than 5%, and a volume resistivity of 1.0×

10¹⁰ Ω

·

cm or more.

2. The capacitive sensor according to claim 1, wherein

the insulating layer has a tensile modulus of greater than 10 MPa.

3. The capacitive sensor according to claim 1,

wherein

the insulating layer contains an elastomer and an anti-blocking agent.

4. The capacitive sensor according to claim 3, wherein

the insulating layer contains 18 parts by mass or more and less than 107 parts by mass of the anti-blocking agent per 100 parts by mass of the elastomer.

5. The capacitive sensor according to claim 3, wherein

the anti-blocking agent contains at least either titanium oxide particles or silica particles.

6. The capacitive sensor according to any one of claim 1, wherein

the electrode unit has a substrate, and

the insulating layer, the electrode layer, and the jumper wiring layer are formed on one side of the substrate in the front-back direction.

7. The capacitive sensor according to claim 1, wherein

the electrode layer and the jumper wiring layer contain an elastomer.

8. The capacitive sensor according to claim 1, wherein

the electrode unit placed on a front side of the dielectric layer is a front-side electrode unit, and the electrode unit placed on a back side of the dielectric layer is a back-side electrode unit,

in the front-side electrode unit, the electrode layer is formed by a plurality of front-side electrode layers arranged parallel to each other, and the jumper wiring layer is formed by a plurality of front-side wiring layers electrically connected to the plurality of front-side electrode layers,

in the back-side electrode unit, the electrode layer is formed by a plurality of back-side electrode layers arranged parallel to each other, and the jumper wiring layer is formed by a plurality of back-side wiring layers electrically connected to the plurality of back-side electrode layers, and

the plurality of front-side electrode layers and the plurality of back-side electrode layers extend in such a direction that the plurality of front-side electrode layers cross the plurality of back-side electrode layers, and a plurality of detection units are formed in portions where the plurality of front-side electrode layers overlap the plurality of back-side electrode layers, as viewed from a front side or a back side.

9. A method for manufacturing the capacitive sensor according to claim 6, comprising:

an electrode unit producing step of producing the electrode unit; and

a placing step of placing the electrode unit on both sides of the dielectric layer in the front-back direction such that the substrate faces outward, wherein

the electrode unit producing step includes

a first printing step of forming one of the electrode layer and the jumper wiring layer on one side of the substrate in the front-back direction by a printing method,

a second printing step of forming the insulating layer by a printing method such that the insulating layer covers the printed electrode layer or jumper wiring layer, and

a third printing step of forming the other of the electrode layer and the jumper wiring layer by a printing method such that the other of the electrode layer and the jumper wiring layer covers the through hole in the insulating layer.

10. The method according to claim 9, wherein

the printing method in the first printing step, the second printing step, and the third printing step is screen printing.

11. A sensor sheet including the capacitive sensor according to claim 8, comprising, as viewed from a front side or a back side:

a pressure sensitive region where the plurality of detecting units are formed; and

a dead region placed next to the pressure sensitive region in a planar direction, and having an extended portion from which an amount of electricity regarding capacitance of the plurality of detection units can be obtained from outside,

the insulating layer of the front-side electrode unit is a front-side insulating layer placed on a front side of the front-side electrode layer,

the through hole extending through the front-side insulating layer is a front-side through hole,

the insulating layer of the back-side electrode unit is a back-side insulating layer placed on a back side of the back-side electrode layer,

the through hole extending through the back-side insulating layer is a back-side through hole,

the front-side wiring layer is placed on a front side of the front-side insulating layer and electrically connects the front-side electrode layer and the extended portion via the front-side through hole,

the back-side wiring layer is placed on a back side of the back-side insulating layer and electrically connects the back-side electrode layer and the extended portion via the back-side through hole,

a front-side detection path running through at least the front-side wiring layer and a back-side detection path running through at least the back-side wiring layer are formed between each of the plurality of detection units and the extended portion, and

a sensor body having at least one of the detection units, the extended portion, and the front-side detection path and the back-side detection path for the detection unit is allowed to be cut from the sensor sheet.

12. The sensor sheet according to claim 11, wherein

a contact between the front-side wiring layer and the front-side electrode layer is a front-side contact, and a contact between the back-side wiring layer and the back-side electrode layer is a back-side contact,

a plurality of the back-side contacts are placed so as to overlap the front-side electrode layer closest to the extended portion, as viewed from the front side or the back side, and

a plurality of the front-side contacts are placed so as to overlap the back-side electrode layer closest to the extended portion, as viewed from the front side or the back side.

13. The sensor sheet according to claim 11, wherein

a contact between the front-side wiring layer and the front-side electrode layer is a front-side contact, and a contact between the back-side wiring layer and the back-side electrode layer is a back-side contact, and

the front-side contact and the back-side contact are individually placed in all of the detection units.

14. A capacitive sensor, comprising:

a sensor body cut from the sensor sheet according to claim 1; and

a control unit that is electrically connected to the extended portion and that, in a case where the sensor body has the detection unit that has been partially cut away, corrects the amount of electricity regarding the capacitance of the detection unit.

15. A method for manufacturing the capacitive sensor according to claim 14, comprising:

a cutting step of cutting the sensor body from the sensor sheet.