| 摘要 |
PURPOSE:To simultaneously process a plurality of blind holes by removing insulating layers except insulating layers set to the same size in the thickness of layers by drilling at the time of forming recesses, and then removing a residual insulating layer by powder beam etching. CONSTITUTION:A mask 17 is formed on a main surface 12c of an insulating layer 12 in which a first conductor layer 13 and a second conductor layer 14 having different depth positions are previously buried therein, through a third conductor layer 15. Two sets of through holes 15a, 17a, 15b, 17b communicating with each other are formed at the mask 17 and the layer 15 by drilling, and part of the layer 12 of a part corresponding to a blind hole is removed. The layer 12 is partly retained, and the thicknesses of residual insulating layers (a), (b) are set to the same. The layers (a), (b) are removed by powder beam etching to form recesses 12a, 12b on the layer 12, and two blind holes 18, 19 are formed. After the mask 17 is removed, a connecting layer 16 by plating is formed. |
