| abstract |
The present invention provides a manufacturing method, which is a manufacturing method of high mass productivity for realizing multi-layer wiring, and which can be established in the circuit device mounting a ceramic board, a flexible sheet and the like as a support board. In the present invention, a conductive pattern 41 of a first layer isolated by an isolation trench 31 is formed on a conductive foil 30, and a plurality of layers of the conductive patterns 43 are formed thereon to create a multi-layered wiring structure. Furthermore, a circuit element 46 is mounted and molded with an insulating resin 50 and the back surface of the conductive foil 30 is etched. As a result, the manufacturing method suitable to a mass production for saving resources, can be realized with a circuit device having the multi-layered structure of the patterns 41 and 43. |