abstract |
(57) [Abstract] [Purpose] Inside a large number of cavities formed in the circuit board, Efficiently fill the sealing resin. [Structure] A multi-cavity circuit board 10 in which a large number of cavities 12 are formed, a sealing resin sheet 20 made of crosslinked polyolefin, and a surface molding release sheet 3 1 and the weight plate 32 are sequentially stacked, and the vacuum heating furnace 33 Place inside and heat in vacuum. Sealing resin sheet 20 When heated, the resin melts and becomes in a state of being filled in each cavity 12. Further, by heating the multiple cavity circuit board 10, the molten resin filled in each cavity 12 is cured. |