US 11,877,395 B2
Thermoplastic liquid crystal polymer film and circuit board using same
Minoru Onodera, Kurashiki (JP); Tatsuya Sunamoto, Chiyoda-ku (JP); Takeshi Takahashi, Kamisu (JP); and Takahiro Nakashima, Kamisu (JP)
Assigned to KURARAY CO., LTD., Kurashiki (JP)
Filed by KURARAY CO., LTD., Kurashiki (JP)
Filed on Apr. 30, 2021, as Appl. No. 17/245,542.
Application 17/245,542 is a continuation of application No. PCT/JP2019/043658, filed on Nov. 7, 2019.
Claims priority of application No. 2018-210197 (JP), filed on Nov. 8, 2018.
Prior Publication US 2021/0251074 A1, Aug. 12, 2021
Int. Cl. C09K 19/38 (2006.01); H05K 1/03 (2006.01); H05K 1/02 (2006.01); B32B 15/08 (2006.01); B32B 7/027 (2019.01)
CPC H05K 1/0313 (2013.01) [B32B 7/027 (2019.01); B32B 15/08 (2013.01); C09K 19/38 (2013.01); H05K 1/0298 (2013.01); B32B 2457/08 (2013.01); H05K 1/024 (2013.01); H05K 2201/0129 (2013.01); H05K 2201/0141 (2013.01)] 16 Claims
 
1. A thermoplastic liquid crystal polymer film (or TLCP film) comprising a thermoplastic polymer capable of forming an optically anisotropic melt phase, wherein the TLCP film has a dielectric constant of from 2.5 to 3.2 in a thickness direction of the film at a temperature of 23° C. and a frequency of 20 GHz, and a heat deformation temperature of from 180 to 320° C., wherein the thickness direction of the film is perpendicular to planar directions of the film which are along a film plane of the film; wherein the TLCP film has dielectric constants in a relationship represented by the following formula (1):
0≤|(Dx+Dy)/2−Dz|≤0.9  (1)
wherein Dx denotes a dielectric constant in, among planar directions of the film, one direction of the film on a film plane, Dy denotes a dielectric constant in a direction perpendicular to the one direction of the film on the film plane, Dx and Dy being measured at a temperature of 23° C. and a frequency of 15 GHz, and Dz denotes a dielectric constant in the thickness direction of the film measured at a temperature of 23° C. and a frequency of 20 GHz.