| 摘要 |
PURPOSE:To enable to form a minute through-hole stably and in high density in a polyimide resin film by a method wherein photo resist masks having a pattern of opening of the prescribed shape are provided doubly on the polyimide resin film. CONSTITUTION:The thin photo resist film 5 having the prescribed pattern is provided on the polyimide resin film 2 formed on a substrate 1. The photo resist film 6 having the pattern provided with the opening part larger than the opening part of the film 2 is provided thereon as the opening part of the film 5 to be positioned in the opening part of the film 6. Then the film 2 is etched with a corrosive liquid making the double photo resist film consisting of the films 5, 6 as a mask. As a result, the taper angle theta of the film 2 is enlarged according to the increase of the distance (x) from the circumferential edge of opening part of the film 5 to reach the circumferential edge of opening part of the film 6. Namely, by selecting the value of the distance (x) properly, the value of taper angle theta can be controlled optionally, and density of the through-hole can be controlled with high precision. |
