Material for printed circuit board, metal laminate, methods for producing them, and method for producing printed circuit board

A method for producing a material for a printed circuit board, comprising:

• subjecting a film (A) provided with a fluorinated resin layer comprising a composition comprising a fluorinated copolymer (a) to a heat treatment to obtain a material for a printed circuit board, wherein
• the film (A) is a film (A1) consisting of the fluorinated resin layer or an adhesive film (A2) having the fluorinated resin layer directly laminated on at least one side of a heat resistant resin film,
• the fluorinated copolymer (a) has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group and an isocyanate group, has a melting point of from 280 to 320° C., and has a melt flow rate of at least 2 g/10 min measured at 372° C. under a load of 49N, and
• the heat treatment of the film (A) is carried out at a temperature of at least 250° C. and lower by at least 5° C. than the melting point of the fluorinated copolymer (a) so that the ratio of the following melt flow rate (II) (MFR(II)) to the following melt flow rate (I) (MFR(I)) [MFR(II)/MFR(I)] is from 0.05 to 0.5 and that the following MFR(II) is at most 15 g/10 min, wherein,
• MFR(I):
• the melt flow rate of the fluorinated resin layer before the heat treatment measured at 372° C. under a load of 49N;
• and
• MFR(II):
• the melt flow rate of the fluorinated resin layer after the heat treatment measured at 372° C. under a load of 49N.