| 摘要 |
PROBLEM TO BE SOLVED: To allow two types of vias to coexist by forming photo-vias through a photosensitive resin layer and laser-vias through this layer hardened by baking. SOLUTION: After forming a photosensitive resin layer 30 photo-vias 40 are developed and this layer 30 is hardened by baking. A photo resist 50 is applied, a laser-via pattern is backed thereon, a photo mask 52 is aligned and overlaid. It is exposed to an ultraviolet ray, etc., to form a latent image of the laser-via pattern on the photo resist 50. It is developed and unexposed parts of the photoresist 50 is removed, the remaining photoresist 50 is hardend, a first Cu plating layer 38 is etched to form small openings 18A for the laser-vias, the small openings 18A are irradiated with laser beams one after another to form small holes 22A, and vias 26A for connecting Cu foils 12 to Cu plating layers 24A, 38 are formed to allow the two types of vias to coexist. |
