Method of making liquid crystal polymer films

A method of making a thermotropic liquid crystal polymer film, which comprises:

• continuously heat treating an extruded thermotropic liquid crystal polymer film joined to a sheet-like support member;
• and
• subsequently separating the heat-treated thermotropic liquid crystal polymer film from the support member;
• wherein the continuous heat treatment of the thermotropic liquid crystal polymer film joined to the support member is carried out for a heating time of 5 to 60 seconds at a heating temperature T° C. equal to or higher than the melting point Tm° C. of the thermotropic liquid crystal polymer film less 15° C. (i.e., Tm−15° C.), but lower than the melting point Tm° C. (thus, Tm−15° C.≦T° C.<Tm° C.), to thereby increase the thermal expansion coefficient of the thermotropic liquid crystal polymer film,
• wherein the melting point Tm° C. is the melting point of the extruded thermotropic liquid crystal polymer film before the heat treating, and
• wherein the entire heat treating is carried out at a temperature lower than Tm° C.