Abstract: The invention relates to use of a solder composition exhibiting a desired combination of high creep resistance at typical operating temperatures and low stress in formed solder joints. The invention uses a solder containing 82 to 85 wt. % Au, 12 to 14 wt. % Sn, and 3 to 4 wt. % Ga (optionally with up to 2 wt. % additional elements). The small amount of added Ga induces a significant depression in the liquidus temperatures of both Au and Sn, and thus a depressed melting point (about 27° C. less than eutectic Au—Sn solder), and also provides an enhanced temperature-sensitivity of the solder's creep resistance.

Abstract: A solder composition that bonds well to oxides and other surfaces to which solder bonding is conventionally difficult is provided. The solder is particularly useful for reliable bonding and packaging of optical components that often have oxide surfaces. The solder composition exhibits a microstructure containing a solder matrix in which is distributed fine, micron-scale islands of rare-earth-containing intermetallic particles. The existence of the islands makes the rare earth elements better available for bonding, and reduce the extent to which the rare earths are oxidized. Advantageously, the solder contains Au and/or Ag, in which the rare earth elements tend to have some solid solubility. Due to this solubility, the Au and/or Ag tend to provide some additional protection of the rare earths against oxidation, and thereby also provide accelerated dissolution of the rare earth into the molten solder.

Abstract: Applicants have discovered a new method for fine polishing surfaces of metal-soluble materials such as diamond to the submicron level. The method involves applying to the material surface a polishing medium composed of metal powder and an acidic or basic carrier. The surface is then polished by high speed rubbing to a submicron finish. Several embodiments of apparatus for performing the polishing are described.

Abstract: A novel technique for fine polishing surfaces of diamond to the submicron level involves applying to the diamond surface an oxygen-emitting polishing medium, either a dry powder or a powder dispersed in a liquid carrier. The diamond surface is then polished by high speed rubbing to a submicron finish by inducing oxygen emission and oxygen-carbon interaction. Several embodiments of apparatus for polishing are described.