William Garland Pendleton

US Patent:

51553252, Oct 13, 1992

Filed:

Aug 6, 1991

Appl. No.:

7/740787

Inventors:

Marlin R. McCleaf - Colfax NC
Jeff C. Wu - Clemmons NC
Charles W. Himes - Winston-Salem NC
William E. Pendleton - Greensboro NC
Richard T. Williams - Winston-Salem NC

Assignee:

AMP Incorporated - Harrisburg PA

International Classification:

B23K 2600

US Classification:

21912164

Abstract:

Invention is directed to a method of metallurgically bonding a layer of a first material, such as gold, to the surface of a second material, such as copper, by the use of the driving force of the energy from a pulsed laser. The method comprises the steps of selecting a thin polymeric film, where said polymer is characterized by a high optical coefficient of absorption at the wavelength of said laser, and applying to said polymeric film a thin layer of said first material for bonding to the second material. The second material is placed in close proximity to the thin layer of the first material. Intermediate the laser and the target a rotating optical scanner is provided to intercept the beam of the laser prior to directing the focused beam thereof toward the polymeric film. The repetition rate of the laser is synchronized with the rotating optical scanner to cause the focused beam of the laser to move across said polymeric film at a velocity less than the velocity of sound through the material. As a result thereof, the polymeric film is explosively evaporated causing a build up of pressure driving the first material toward the second material, whereby a moving contact zone is developed therebetween to drive surface contaminants and oxides from the second material.