| 摘要 |
PROBLEM TO BE SOLVED: To reduce the load for etching and resist processing, to improve the size precision and to make a circuit interval small for obtaining a circuit board by a metal-insulator composite member, and to provide a circuit forming method and a product with versatility. SOLUTION: An unnecessary part (circuit gap part) of one metal layer 4A in the composite member 2 formed of a ceramic insulating plate 3 and metal layers 4A and 4B made of aluminum plates is mainly removed by milling. For suppressing cracks due to warp of the board, a metal remaining layer 4Aa is left in a base, and it is desirable that it is removed by etching. Milling is performed after an etching resist thin film layer 5 is given on the surface of the metal layer. Then, milling is performed in two stages. Thus, a step is made in the base of a circuit side, an edge is constituted, and the outer stress can be reduced. COPYRIGHT: (C)2005,JPO&NCIPI |
