Strain sensor, functional film, and method for manufacturing same
A functional film includes a strain resistance film provided on one principal surface of a flexible insulating base. The strain resistance film is a chromium nitride thin-film having a thickness of 150 nm or less. In an X-ray diffraction chart with a CuKα ray as an X-ray source, the strain resistance film has an intensity ratio I 2 /I 1 of 0.001 or more, where the intensity ratio I 2 /I 1 is a ratio of the intensity I 2 of the second peak in a range in which 2θ is 60° to 65° to the intensity I 1 of the first peak in a range in which 2θ is 43° to 45°. The strain resistance film is less liable to crack due to bending, and has a high gauge factor. The functional film is suitably used for a strain sensor.
1 . A functional film that is used for producing a strain sensor, the functional film comprising: a flexible insulating base; and a strain resistance film arranged on one principal surface of the flexible film base, wherein
the strain resistance film is a chromium nitride thin-film having a thickness of 150 nm or less, and
in an X-ray diffraction chart with a CuKα ray as an X-ray source, the strain resistance film has an intensity ratio I 2 /I 1 of 0.001 or more, where the intensity ratio I 2 /I 1 is a ratio of an intensity I 2 of a second peak in a 2θ range of 60° to 65° to an intensity I 1 of a first peak in a 2θ range of 43° to 45°.
2 . The functional film according to claim 1 , wherein the strain resistance film has a gauge factor of 10 or more.
3 . The functional film according to claim 1 , wherein the strain resistance film has a temperature coefficient of resistance of −600 to 600 ppm/° C.
4 . The functional film according to claim 1 , wherein the flexible insulating base is a resin film.
5 . The functional film according to claim 1 , wherein the functional film is provided as a wound body of a continuous length film.
6 . A method for manufacturing the functional film as set forth in claim 1 , wherein the strain resistance film is deposited by a sputtering deposition with using a Cr target and introducing argon and nitrogen.
7 . The method according to claim 6 , wherein the sputtering deposition is performed by roll-to-roll sputtering.
8 . The method according to claim 6 , wherein in the sputtering deposition, an introduction amount of nitrogen is 0.5 to 15 parts by volume based on 100 parts by volume of an introduction amount of argon.
9 . The method according to claim 6 , wherein a deposition pressure in the sputtering deposition is 0.20 Pa or less.
10 . A strain sensor film comprising: a flexible insulating base; and a patterned sensor wiring arranged on one principal surface of the flexible film base, wherein
the sensor wiring is a chromium nitride thin-film having a thickness of 150 nm or less, and
in an X-ray diffraction chart with a CuKα ray as an X-ray source, the sensor wiring has an intensity ratio I 2 /I 1 of 0.001 or more, where the intensity ratio I 2 /I 1 is a ratio of an intensity I 2 of a second peak in a 2θ range of 60° to 65° to an intensity I 1 of a first peak in a 2θ range of 43° to 45°.