Inventors:
Richard J. Coyle - Lawrenceville NJ
Kevin M. Hogan - Sinking Spring PA
Paul J. Sakach - Vincentown NJ
Patrick P. Solan - Robbinsville NJ
Assignee:
AT&T Bell Laboratories - Murray Hill NJ
International Classification:
B23K 2600
Abstract:
Welding a first body (11) of a first metal which has been plated on one surface thereof with a layer (13) of a second metal comprises the step of vaporizing a portion of said layer. This is done by directing a first pulsed laser beam (17) at the layer (13), the first pulsed laser beam having a first relatively high peak power and a first relatively low pulse duration. The vaporizing results in exposure of a portion of the first body (11). Thereafter, part of the first body is melted by directing a second pulsed laser beam (20) at the exposed portion of the first body, said second pulsed laser beam having a second peak power smaller than the first peak power and a second pulse duration longer than said first pulse duration. By using the same laser (18) in a two-step process, first to vaporize a portion of the plating, such as gold plating on Kovar, and thereafter using the same laser for making the weld, one can avoid a microcracking problem in a manner that is quick, simple and convenient.