CONTROLLED SOLDER INTERDIFFUSION FOR HIGH-POWER SEMICONDUCTOR-LASER DIODE DIE BONDING

High power semiconductor laser diodes and optical power amplifiers hav e important roles in solid state laser and optical fiber pumping, opti cal storage and recording, and can serve as efficient sources for medi cal and display applications, These high power devices must be mounted in the epitaxy-side down configuration for good heat transfer and so require a well-controlled, high yield, void-free, die attach method, W e have developed a method which consistently yields absolute thermal r esistances of 1.5 degrees C/W (+/-4%) on tapered angle facet semicondu ctor optical amplifiers and specific thermal resistances of 0.004 degr ees K.cm(2)/W for lasers and optical amplifiers mounted on oxygen free high conductivity (OFHC) copper heatsinks, Our method has wide proces s margins, exhibits excellent yield (>95%, N = 30) and repeatability, relaxes the requirements for highly polished heatsinks, and is well su ited for laser die attach to heatspreading diamond submounts or advanc ed composite materials.