Abstract: Ceramic substrates (1) for microelectronic modules are formed in multiple layers (7 & 9) fused into a unitary one-piece assembly. The layers contain the same ceramic material but in different purity so that one outer layer (9) is optimal in composition for bonding to a thick film conductor (11) and the other outer layer (7) is optimal in composition for bonding to a thin film conductor (13). In a dual composition substrate embodiment one layer is formed of a 96% alumina composition and the second layer is formed of a 99.6% alumina composition.

Abstract: Ceramic substrates (1) for microelectronic modules are formed in multiple layers (7 & 9) fused into a unitary one-piece assembly. The layers contain the same ceramic material but in different purity so that one outer layer (9) is optimal in composition for bonding to a thick film conductor (11) and the other outer layer (7) is optimal in composition for bonding to a thin film conductor (13). In a dual composition substrate embodiment one layer is formed of a 96% alumina composition and the second layer is formed of a 99.6% alumina composition.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.