| 摘要 |
PURPOSE:To simplify dissolving, and enable the processing of large amount, by adopting aqueous liquid containing NaOH as smear eliminating solution. CONSTITUTION:Inner layer material made of polyimide resin, on which an inner layer pattern is formed, is constituted in a prescribed combination, and then integrated in a multilayer structure, which is bored by a drill. The multilayer printed board is dipped for 3-6 minutes in aqueous liquid which contains 5-25% of NaOH and is heated at 60-80 deg.C, and generated smear is eliminated. By hot water washing and the like, NaOH is eliminated. If rocking is applied at the time of dipping, irregularities are desirably reduced. The smear elimination of polyimide resin multilayer printed board is enabled in a continuous process of large amount, with simple manner and low cost, thereby obtaining a high quality through hole. |
