US 12,414,475 B2
Piezoelectric film having a vinylidenefluoride/tetrafluoroethylene copolymer film
Tetsuhiro Kodani, Osaka (JP); Saori Sakami, Osaka (JP); Shinya Bitou, Osaka (JP); Takashi Kanemura, Osaka (JP); and Akinari Sugiyama, Osaka (JP)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP)
Appl. No. 17/285,778
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP)
PCT Filed Oct. 16, 2019, PCT No. PCT/JP2019/040565
§ 371(c)(1), (2) Date Apr. 15, 2021,
PCT Pub. No. WO2020/080382, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 2018-195261 (JP), filed on Oct. 16, 2018; and application No. 2019-143046 (JP), filed on Aug. 2, 2019.
Prior Publication US 2021/0384411 A1, Dec. 9, 2021
Int. Cl. H01L 41/45 (2013.01); H01L 41/193 (2006.01); H01L 41/257 (2013.01); H10N 30/045 (2023.01); H10N 30/098 (2023.01); H10N 30/857 (2023.01)
CPC H10N 30/857 (2023.02) [H10N 30/045 (2023.02); H10N 30/098 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A piezoelectric film comprising a vinylidene fluoride/tetrafluoroethylene copolymer film and having a residual polarization amount of 40 mC/m2 or more, wherein a ratio of internal haze value [%]/film thickness [μm] is more than 1.0, and
wherein the residual polarization amount is determined based on a measured response when a sample is provided and an electric field of 120 MV/m is applied, the sample being an aluminum flat electrode patterned by vacuum deposition on a center of the piezoelectric film and having two lead electrodes attached thereto with conductive double-sided tape.