| 摘要 |
<p>It is made possible to form via holes with ease, and a satisfactory via hole shape is realized to eliminate continuity failure. An insulation layer is formed on a first wiring layer, and after the insulation layer is formed with an opening, a second wiring layer is formed. In forming the opening, a laser beam is radiated to the insulation layer with its focal point deviated. Deviating the focal point of the laser beam results in the taper angle of the opening being widened and the lateral wall becoming an inclined surface, and when a wiring layer is formed thereon, it reliably adheres also to the lateral wall.</p> |
