Abstract: A vacuum hot platen press for pressing laminated boards includes a seal cover assembly for keeping the internal process chamber airtight. The seal cover assembly is fixed in an airtight manner to a cylinder plate located below the platens, through which the pressure cylinders extend in an airtight manner. The upper end of the cover assembly is in sliding airtight contact with the tensile strength members of the press. The sliding contact prevents elongation of the tensile members under pressing force, or vacuum forces on the cover assembly, from causing distortion or breakage.

Abstract: The present invention relates to a hot press to manufacture a substrate in which a printed circuit is provided.The hot press comprising at least one of vertically movable heating plates, a freely elevating movable platen which elevates the heating plates to press a plate to be treated between the heating plates, and a detecting means for detecting the movement of the uppermost heating plate when said uppermost heating plate starts to be elevated, in which the elevating speed of the movable platen is changed to a lower speed by a signal generated from the detecting device.This low speed control is carried out as follows.