Technique for laser welding dissimilar metals

A method of welding electrically conductive ribbon comprising a first material having a first melting point to electrically conductive wire comprising a second material having a second melting point, the first melting point being substantially lower than the second melting point, the method comprising the steps of:

• (a) forming an aperture in the ribbon with an opening smaller than the diameter of the wire;
• (b) positioning the ribbon in engagement with the wire such that the aperture in the ribbon is generally coextensive with the wire;
• (c) directing a laser beam transversely of the ribbon through the aperture in the ribbon and onto the wire to simultaneously melt the wire and the ribbon in the region of the aperture and create a homogeneous mix of the first material with the second material in the region surrounding the aperture;
• and
• (d) discontinuing operation of the laser beam to allow solidification of the homogeneous mix of the first material with the second material in the region surrounding the aperture to thereby achieve a welded connection between the ribbon and the wire.