Patent ID: 7811408

Claim:
A method for producing a metal-clad laminate, comprising: a thermoplastic liquid crystal polymer film (A) having a thermoplastic liquid crystal polymer capable of forming an optically anisotropic melt phase; and a metallic sheet bonded to at least one surface of the film; wherein the method comprises: preparing the thermoplastic liquid crystal polymer film (A) having a melting point; thermally compressing the metallic sheet and the thermoplastic liquid crystal polymer film (A) at a nipping region between heating rolls to bond them together to obtain a metal-clad laminate; and heat treating the obtained metal-clad laminate at a heat treating temperature in a range from 5° C. to 20° C. lower than the melting point of the thermoplastic liquid crystal polymer film (A); wherein preparing the thermoplastic liquid crystal polymer film (A) comprises: laminating a support and a thermoplastic liquid crystal polymer film (B) having thermal and mechanical properties along a mechanical and a transverse axis; thermally compressing the support and the thermoplastic liquid crystal polymer film (B) to obtain a laminated sheet; heating the laminated sheet at a temperature in a range of from 10° C. lower than a melting point of the thermoplastic liquid crystal polymer film (B) to 10° C. higher than the melting point of the thermoplastic liquid crystal polymer film (B) to obtain a coefficient of thermal expansion in the longitudinal direction (αL), and a coefficient of thermal expansion in the transverse direction (αT) of the thermoplastic liquid crystal polymer film (A); and peeling off the support from the heated laminated sheet to obtain the thermoplastic liquid crystal polymer film (A); wherein the thermoplastic liquid crystal polymer film (A) has the obtained coefficient of thermal expansion in the longitudinal direction (αL), the obtained coefficient of thermal expansion in the transverse direction (αT), a thickness (T), a thickness coefficient (β) and an anisotropy coefficient (γ) which satisfy the formula, α L =βT +γ, and wherein the thickness coefficient β of the thermoplastic liquid crystal polymer film (A) is within the range of −0.08(×1/(μm ×° C.)) to −0.01(×1/(μm ×° C.)), the anisotropy coefficient γof the thermoplastic liquid crystal polymer film (A) relative to a thermal expansion coefficient (αM) of the metallic sheet is within the range of (αM +6)(10 −6 /° C.)≦γ≦(αM+10)(10 −6 /° C.), and the coefficient of thermal expansion in the transverse direction (αT) of the thermoplastic liquid crystal polymer film (A) relative to the thermal expansion coefficient αM of the metallic sheet is within the range of (αM−2 )(10 −6 /° C.)≦αT≦(αM +3)(10 −6 /° C.).