Patent ID: 6103016
Filing Date: 2000-08-15
Classification: B24C,H05K

Abstract:
A method of mitigating electrostatic discharges occurring during cleaning of a substrate when solid CO.sub.2 particles are directed against a major surface of the substrate wherein the improvement comprises the steps of:placing the substrate a moisture-containing atmosphere; andchilling the substrate prior to directing the solid CO.sub.2 particles thereat to cause moisture in the moisture-containing atmosphere to condense on the major surface of the substrate to form a substantially continuous film of water directing the solid CO.sub.2 particles against the major surface of the substrate, reacting the CO.sub.2 particles with the water film to form carbonic acid (H.sub.2 CO.sub.3), wherein said carbonic acid dissociates into free ions that neutralize the electrostatic charges on the solid CO.sub.2 particles.