Abstract: A method for reflowing solder without flux includes the steps of placing a first metallic element in contact with a second, solder-plated element, thereby defining a bond site; and causing a laser beam to impinge on the bond site. An apparatus for performing the above method is also disclosed.

Abstract: A method is disclosed for laser bonding two highly reflective electrical members. The first electrical member is coated with a coating alloy containing the metal of the second electrical member and a coupling material that is well absorbent of laser energy at the laser beam wavelength, has a lower melting point than either of the electrical members, and has a low solubility in a solid bond alloy of the electrical members. The laser characteristics are selected so that as bonding occurs a bond alloy of the electrical members solidifies and a solidification front drives the molten coupling material away from the bond interface toward the exterior periphery of the bond, so that substantially all of the solidified bond interface and bond interface strength results from the bond alloy. Coating a copper lead with a coating alloy containing gold and a coupling material, and then contacting the coated copper lead with a gold bonding pad provides for gold-to-gold TAB tape laser bonding.

Abstract: A method of bonding a first plurality of electrical contacts to a second plurality of electrical contacts by aligning the first and second contacts, placing a diaphragm member against the first contacts and applying a differential pressure, such as a vacuum, to the diaphragm in a direction to pull the first contact toward the second contact. Thereafter, the first contacts are bonded to the second contacts with a laser. The diaphragm or a coating on the diaphragm can be a material that absorbs energy from the laser to transfer laser energy to the bond. The diaphragm may be a glass plate or a transparent membrane, may have a support bonded to the first contacts, and may include openings through which the contacts are bonded.