Abstract: When an alkaline earth metal carbonate powder is mixed with an adhesive and is formed into an adhesive layer in a conventional covering method, a problem of the transfer of catalyst for electroless plating during a masking step or later electroless plating step is solved. Further, blisters under plated film caused by a fire retardant contained in an insulating substrate is also overcome by the use of alkaline earth metal powder.

Abstract: A plastic film is formed by annealing a molten tubular film in a first enclosed space and immediately thereafter directing cold air perpendicular to the axis thereof and expanding and solidifying the film in a second enclosed space while in contact with cold air flowing parallel to film travel.

Abstract: A process for producing a printed circuit board which comprises forming a plating film forming adhesive layer on the whole exposed surface of an insulating board, roughening said adhesive layer surface, depositing a catalyst for electroless copper plating on said adhesive layer surface from a catalyst solution, masking the thus treated insulating board surface excepting the part where a circuit is to be formed, and then performing the electroless copper plating on the catalyst of the board to form a circuit thereon, wherein an improvement comprises treating the roughened adhesive layer surface with an alkaline solution before depositing the catalyst thereon and treating the masked insulating board with an aqueous solution containing a surfactant before performing the electroless copper plating. The above process assures a higher copper utilization and a large adhesive strength of the copper plating to the board.