| abstract |
The present invention provides: a method for producing an LCP film for circuit boards, said method enabling the achievement of an LCP film for circuit boards having a low linear expansion coefficient and excellent dimensional stability without excessively deteriorating excellent basic properties of a liquid crystal polyester including excellent mechanical characteristics, electrical characteristics and heat resistance; and the like. A method for producing an LCP film for circuit boards, said method being characterized by comprising at least: a composition preparation step wherein an LCP resin composition containing at least 100 parts by mass of a liquid crystal polyester and from 1 to 20 parts by mass of a polyarylate; a film formation step wherein an LCP film melt-extruded from a T-die, said LCP film having a linear expansion coefficient (α2) of 50 ppm/K or more in the TD direction, is formed by melt-extruding the LCP resin composition from a T-die; and a pressurizing and heating step wherein the LCP film melt-extruded from a T-die is pressurized and heated, thereby obtaining an LCP film for circuit boards, said LCP film having a linear expansion coefficient (α2) of 16.8 ± 12 ppm/K in the TD direction. |