Hot press for use in production of multilayered substrate

Abstract

A hot press for producing a multilayered substrate including vertically opposing upper and lower bolsters relatively movable toward each other to press multilayered substrate blanks and to cool the plates after the bonding. A sealing arrangement includes a cylinder and encloses the upper and lower bolsters so as to define a hermetically sealed space, with an evacuating arrangement reducing the pressure inside the hermetically sealed space during heating and pressing in which a bonding agent in the multilayered substrate blanks is softened. A high-pressure gas supplying arrangement supplies a pressurizing gas into the hermetically sealed space so as to impart the bonding pressure. A pressure sensor detects the pressure inside the hermetically sealed space, and a controller effects a compensation for incremental increases in the bonding pressure when the pressure inside the hermetically sealed space is reduced by the evacuating arrangement and for incrementally decreasing the bonding pressure when the pressure inside the space is elevated by the pressurized gas, by feedback output signals of the pressure sensor to the hydraulic pressure source.