| 摘要 |
PURPOSE:To eliminate the defective molding of a semiconductor and obtain a vacuum tablet excellent in reliability by a method wherein molding resin, which is heated up to its softening point, is shaped under vacuum into the form of tablet and the resultant tablet is cooled in refrigerant. CONSTITUTION:Powder 1, the amount of which is necessary for making one vacuum tablet 10, is charged on a hopper 2, which is heated in advance up to the softening point of the powder 1 and, after that, a shutter 9 is closed so as to evacuate the interior of a cylinder 8. When the powder 1 is heated up to its softening point, a piston 5 is moved so as to compress the powder 1 in order to shape it. Because the powder is under soft state, particles contact and weld with one another, resulting in shaping the vacuum tablet 10, in the interior of which no bubble exists. The hot vacuum tablet 10 is immersed in liquid nitrogen 11 so as not to develop ununiform temperature difference between the interior and the exterior of the vacuum tablet due to the progress of reaction by heating and the consequent shortening of gel time. Because the interior of the tablet is cooled down to 10 deg.C in several minutes and the ununiformity of gel time due to the difference between the temperature of the interior and that of the exterior of the taken-out tablet, a vacuum tablet, which develops no gold line deformation at molding, can be manufactured. |
