Apparatus for enclosing semiconductors with resin by molding

An apparatus for enclosing semiconductors with resin by molding comprising a stationary upper mold and a movable lower mold opposed thereto, a plurality of cavities formed in the mold surfaces of said upper and lower molds, a pluraltiy of pots in said upper mold, each of said pots being disposed so as to communicate with a predetermined number of said cavities without through main and auxiliary runners and including openings at the uper end thereof for receiving the resin, a plunger in each of said pots for pressurizing the resin received in the associated pot and for forcing the pressurized resin into said cavities and a resin material pressurizing mechanism disposed above said upper mold, said resin material pressurizing mechanism comprising a plurality of pistons and cylinders individual to but separate from said plungers and a like plurality of rocker arms disposed between individual pairs of said pistons and plungers for transmitting movement of a said piston into movement of the corresponding plunger, said cylinders being connected to individual channels for a fluid pressure medium, said plungers being arranged in a row in a plunger mounting frame and said cylinders being formed in said plunger mounting frame and arranged in two rows in staggered relationship on opposite sides of the row of plungers, sad rocker arms being located between the associated piston and plunger such that the opposite ends of each rocker arm contact the upper ends of the associated piston and plunger, and said rocker arms being mounted on swing shafts arranged in staggered rows on opposite sides on the row of plungers, said apparatus further comprising a plurality of biasing springs, located in the plunger mounting frame and individually associated with a corresponding one of said plungers, for biasing said plungers upwardly to an inoperative position thereof.