| 摘要 |
PURPOSE: To obtain a multilayer flexible printed circuit board, which is easy in through-hole processing, does not need a desmear treatment, is good in platability and has the high reliability of connection, by a method wherein insulating materials constituting the circuit board are all constituted of a polyimide. CONSTITUTION: Insulating materials constituting a multilayer flexible printed circuit board formed by laminating a plurality of flexible printed circuit boards are all formed of a polyimide. A polyimide adhesive film is inserted between the two-layer flexible printed circuit boards subjected to prescribed patterning and with insulating layers, which are all constituted of the polyimide and are formed on the surfaces and rears of the circuit boards, and is bonded by thermocompression to the printed circuit boards to manufacture the multilayer flexible printed circuit board. As the two-layer flexible printed circuit boards, one coated with a covering coat consisting of the polyimide is used. The polyimide adhesive film is formed, for example, by a method wherein a polyamic acid solution is applied to both surfaces of a polyimide film using a bar coater and is dried for 15 minutes at 110 deg.C or for 15 minutes at 250 deg.C. |
