PURPOSE: To obtain a conductive substrate free from defects, such as uneven dryness and stains by giving immersion washing to the surface of a conductive substrate in pure water, pulling up the substrate before giving it vibration to rapidly and surely perform dewatering and drying after washing.
CONSTITUTION: A cylindrical substrate machined undergoes washing treatment. For example, 5% pure water solution of 690 polar clean as washing liquid 18 for the 1st washing tank 11 and pure water as washing liquid for the 2nd-4th washing tanks 21, 31, 41 are used. The washing liquid 18 for the 1st washing tank 11 is heated to 50°C and the temps. in the washing liquid in the 2nd-4th washing tanks 21, 31, 41 each are 25°C and the immersion times of the 1st-4th washing tanks are each 2min. The cylindrical substrate 1 given washing treatment is put on a dewatering vibration base for an ultrasonic vibration dewatering device installed in a clean booth kept at 100 cleanness and 40°C atmospheric temp. and ultrasonic wave of 28kHz is oscillated for 10sec. Thus the occurrence of repelling, stains due to defective washing and uneven dryness, stains, etc., is prevented.
MATSUMOTO MASANORI
SAKAMOTO MASAYUKI
MORITA TATSUHIRO
MATSUMOTO HIROSHI
NAKAI TAKAO
