Process for manufacturing printed circuit boards and a machine for this purpose

Abstract

Process and machine for manufacturing printed circuit boards wherein a press packet comprised of at least two press plates of metal material between which is arranged a printed circuit board composition formed by one or more metal sheets, by one or more layers of insulating material impregnated with polymerizable resins and/or by one or more printed circuit boards with an engraved image of a circuit, are arranged between the press plates of a press and is pressed, subjecting said press packet to the action of a variable induction magnetic field which generates induced currents in each metal plate and sheet of the press packet, causing the heating of said plates and sheets, in turn causing the heating by thermal conduction of the layers of insulating material, melting and liquefying the resins in said layers of insulating material and adhering the insulating material to the metal sheets, so that, on raising the temperature even more, the polymerizable resins in the layers of insulating material are then polymerized, resulting, after the cooling of the press packet, in one or more rigid boards suitable for making printed electronic circuits. The machine to carry out the above process comprises a variable induction magnetic field generating device adapted to generate induced currents in the press packet's metal plates and sheets, causing them to heat, and means of controlling the operation of the magnetic field generating device and controlling the temperature and pressure to which the press packet is subjected.

1 . An apparatus comprising:
 an upper press plate which is capable of vertical displacement;   a lower press plate arranged coaxially with respect to the upper press plate, said lower plate being capable of vertical displacement, the upper and lower plates lacking any device to provide heat and being adapted to receive a press packet between them;   a variable induction magnetic field generation device adapted to apply a variable induction magnetic field in a transverse direction of the press packet, said variable induction magnetic field running generally parallel to the planar surfaces of the press packet and generating induced currents causing heating in the press packet;   a control circuit which controls the frequency and voltage applied to the electromagnetic field generation device, the temperature of the press packet, and the pressure to which the press packet is subjected.   
   
   
       2 . The apparatus of  claim 1 , further comprising temperature probes adapted to be mounted on the press packet. 
   
   
       3 . The apparatus according to  claim 1 , further comprising a vacuuming part which produces a vacuum inside a closed structure of the apparatus. 
   
   
       4 . The apparatus according to  claim 1 , wherein the variable induction field generation device is provided without a magnetic core, and is formed by induction coils within which the upper press plate and the lower press plate are arranged.