| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a printed wiring board comprising a step for forming an insulation layer on a conductor wiring pattern in which the reliability of insulation layer is enhanced by making uniform the thickness. SOLUTION: A build-up method for forming an insulation layer comprises step B for applying a photosensitive insulation material 14a for first layer onto an insulation board 11 including conductor wiring patterns 12, 13, step D for developing and removing the insulation layer on the conductor wiring patterns 12, 13, and step E for smoothing the surface by mechanical polishing. Subsequently, a photosensitive insulation material for second layer is applied, photovias are made, and the surface is polished to obtain a printed wiring board. Since the photosensitive insulation material for second layer can be applied smoothly while filling the gap between patterns, polishing pressure difference caused by coarseness of wiring pattern is eliminated resulting in smooth polishing. |
