| 摘要 |
<p>PURPOSE:To fill a perforated part and form an insulating bonding layer alto gether by forming a double-layer construction of a copper foil with an insulating bonding agent in terms of a first layer with a low flow and a second layer with a high flow and heating and pressuring a perforated metal board and the copper foil. CONSTITUTION:After varnish is applied to a copper foil, 35mum thick, to a prescribed film thickness as a first layer, it is dried at 150 deg.C for 10 minutes. On this coat, another varnish is applied to a prescribed film thickness after drying as a second layer, and it is dried to form a copper foil with an insulating bonding agent. Then, an aluminum sheet of 0.1mm to 2mm in thickness, say 0.3mm thick aluminum sheet, is perforated and treated with surface finish polishing to make the surface a silane coupling. Next, the copper foil with the insulating bonding agent is built over an aluminum sheet by a press, and the perforated part of the aluminum sheet is drilled to perforate to form a through hole. The through hole is plated and circuits on both surfaces are connected. Finally, a pattern 3 is formed by etching.</p> |
