| 摘要 |
PURPOSE:To make via holes all in the shapes of positive tapers by applying an excimer laser to a polyimide film including fillers thereby opening holes immediately before making via holes, and then exposing the part, which is not irradiated with excimer laser yet, to ultraviolet rays so as to develop it. CONSTITUTION:A wiring pattern 2 of lower layer is made on a substrate 1, and a polyimide film 3, wherein photosensitive fillers containing SiO2 are put in, is made all over the surface of this substrate 1, and only the desired part of this polyimide film 3 is irradiated with an excimer laser E through a mask 5, whereby openings are opened in the polyimide film 3 immediately before making via holes 3. Next, the polyimide film 3 is exposed, excluding the places in which to make via holes, to ultraviolet rays S through a glass mask 6 so as to develop it, whereupon via holes 4 in the shapes of positive tapers are made. And the polyimide film 3 is heated and made into imide. Hereby, the connection properties of the via holes between the upper and lower conductive layers can be improved. |
