Patent ID: 6468356
Filing Date: 2002-10-22
Classification: B08B,B29C,H01L

Abstract:
A method for removing residues of molding material from metal parts of plastic packages of semiconductor devices, the method comprising:applying a first pulsed laser radiation to at least one surface region of a metal part covered with residues of molding material, the first pulsed laser radiation having a first wavelength absorbed by the residues of molding material having a thickness greater than a predetermined value, and an intensity and duration of the first pulsed laser radiation causing the residues of molding material having the thickness greater than the predetermined value to be directly attacked; and applying a second pulsed laser radiation to the at least one surface region of the metal part covered with residues of molding material, the second pulsed laser radiation having a second wavelength so that the residues of molding material having a thickness less than the predetermined value are at least partially transparent and the metal part is at least partially absorbent with respect of the second pulsed laser radiation, and an intensity and duration of the second pulsed laser radiation causing formation of plasma at a point of impact with the metal part.