PURPOSE: To reduce the defective fraction by forming a solid resin material as a blank for a package resin-sealing a semiconductor element to a spherical shape.
CONSTITUTION: When the inside of a mold is brought to a vacuum state on mold clamping, air contained in a tablet can also be discharged outside the mold from a clearance between the tablet 21 and the circumferential wall surface 12a of a pot 12. One part of the tablet 21 is pressure-welded to the circumferential wall surface 12a of the pot 12 by the expansion of internal air in a vacuum atmosphere at that time, but the contact area of one part of the tablet is reduced because the tablet 21 is formed to a spherical shape, and the clearance δ2 is not removed completely. Consequently, the tablet having no air component can be moved when the tablet is pushed by a plunger head 13a, thus molding a package with no void. A defective fraction is lowered.
TSUTSUMI KOJI
MORITA YUTAKA
