| 摘要 |
PURPOSE:To prevent a color irregularity from being caused on the surface of a copper circuit by a method wherein the atmospheric condition of a circuit board for inner-layer use is set at 60 deg.C for one minute or less and its surface temperature is set at 50 deg.C or lower until a neutralization treatment after a reduction treatment. CONSTITUTION:The indoor atmospheric condition in which a circuit board for inner-layer use is placed is set at 60 deg.C for one minute or less until, a neutralization treatment is executed after the circuit board for inner-layer use has been reduction-treated by using an acid. Since the circuit board for inner-layer use is exposed to this atmosphere, the surface temperature of the circuit board for inner-layer use is set so as not to exceed 50 deg.C. That is to say, before the neutralization treatment, it is arranged that a reduced film on the surface of a copper circuit does not reach an active point at which the film starts to be dissolved by the acid. The acid on the surface of the copper circuit for the circuit board for inner-layer use is neutralized and removed by a neutralization treatment; after that, the circuit board is immediately washed by water, hot water or the like; it is dried; after that, a multilayer printed wiring board can be manufactured by using the circuit board for inner-layer use; and it is possible to prevent a color irregularity from being caused on the surface of the copper circuit. |
