Abstract: A base plate for a printed circuit board, having a conductive foil heat-bonded to at least one side of a film insulator which comprises from 65 to 35 wt % of a polyarylketone resin and from 35 to 65 wt % of a non-crystalline polyether imide resin and of which the glass transition temperature is from 150 to 230° C. and the peak temperature of crystal fusion is at least 260° C., as measured when the temperature is raised in the differential scanning calorimetry, if necessary after forming a through-hole and filling a conductive paste therein, and of which, after the heat bonding, the heat of crystal fusion &Dgr;Hm and the heat of crystallization &Dgr;Hc generated by crystallization during the temperature rise, as measured when the temperature is raised by the differential scanning calorimetry, satisfy the following relation: [(&Dgr;Hm−&Dgr;Hc)/&Dgr;Hm]≦0.5.