Patent ID: 8034188
Filing Date: 2011-10-11
Classification: B08B,H05K

Abstract:
1. A method for cleaning a surface of a resin layer on which a metal film is formed by plating, comprising the steps of: forming a resin layer on a substrate with a resin compounded with a filler in an amount of 20 wt % or more so that a difference of a coefficient of thermal expansion between the resin layer and the metal film formed on the resin layer is reduced; dipping the substrate in a swelling liquid to swell a portion of the surface of the resin layer; treating the surface of the resin layer with a desmear treatment to remove the swollen portion of the surface of the resin layer to thereby roughen the surface of the resin layer while at least some of the filler previously contained in the swollen portion of the surface of the resin layer remains on the roughened surface of the resin layer after the swollen portion is removed; and removing only the filler remaining on the roughened surface of the resin layer such that the roughened surface of the resin layer is substantially the same as the roughened surface of the resin layer resulting from the desmear treatment, said filler being removed by ultrasonic cleaning in which ultrasonic vibration of a frequency of from 35 to 50 kHz is applied; wherein a peel strength remains approximately constant even when a time period of applying the ultrasonic vibration changes.