| 摘要 |
PURPOSE:To enable a printed board to be remarkably improved in resistance to thermal shock by a method wherein a circuit is formed on a copper plated laminated board, a thermosetting resin layer or a filler containing thermosetting resin layer is formed on both the sides of the laminated board, a copper foil is bonded to the board, and the laminate concerned is formed through thermocompression. CONSTITUTION:Thermosetting resin is applied onto glass cloth as much as 50% by weight, which is dried up into prepreg. A copper foil 3 is provided to both the sides of a prepreg 4, which is thermocompressed into a double-sided copper plated laminated board. Furthermore, both the sides of the copper plated laminated board are subjected to a normal blacking treatment and a multilayer bonding pre-treatment to enable the board to serve as an inner circuit board 2. Then, varnish is applied onto the inner circuit board 2 through a dipping method and dried up. On the other hand, varnish is applied onto the bonding surface of the copper foil 3 and dried up to form a thick film. The laminated material concerned is formed through thermocompression into a four-layered printed board copper plated laminated board. At this point, a prepreg which forms an inner circuit board is set 0.06mm or above in thickness, and an outer thermosetting resin layer or a filler containing thermosetting resin layer is formed as thick as 0.03-0.2mm. |
