| 摘要 |
PURPOSE:To achieve a plated blind hole which cannot be disconnected easily due to thermal shock, thermal expansion, moisture absorption, etc., and is highly, reliable by making the diameter of a blind hole provided at an insulation resin layer to be larger than that of the hole for the blind hole provided at the conductor circuit of an outer layer. CONSTITUTION:The conductor circuit of an outer layer and a conductor circuit 4 of an inner layer are electrically connected via a blind hole 7 through an insulation resin layer 1. In such K kind of multilayer printed wiring board, the diameter of the blind hole 7 provided at the insulation resin layer 1 is larger than that of the hole for the blind hole provided at the conductor circuit of the outer layer at a part in contact with the conductor circuit of the multilayer. Also, the distance between the inner-wall surface of the blind hole 7 provided at the insulation resin layer 1 at the part in contact with the conductor circuit side of the outer layer and the edge part of a fine hole provided at the conductor circuit of the outer layer is two times larger than the thickness of the insulation resin layer 1. Then, the inner wall surface of the blind hole 7 is made smoother. |
