THERMAL MANAGEMENT OF VCSEL-BASED OPTOELECTRONIC MODULES

Thermal management is critical to reliable optoelectronic modules base d on vertical-cavity surface-emitting lasers (VCSEL's). One critical t hermal path to be managed is from a VCSEL to a case (heat sink), which is affected by packaging technologies and materials, The measured VCS EL-to-case resistance of a laser with 8-mu m aperture was 1650 degrees C/W, and that of a 20-mu m device was 1070 degrees C/W. These thermal resistances are much larger than those for the edge-emitting lasers, Advanced device and packaging technologies are being developed to redu ce these resistances, To study the packaging effects, a three-dimensio nal (3-D) numerical model has been developed and calibrated by the mea sured data, The calibrated model was used to understand the difference in thermal behavior: 1) between a wire-bonded and a flip-chip VCSEL m odule, 2) between a single-VCSEL and an 8 x 8 VCSEL module, and 3) bet ween a bottom-cooled and a top-cooled module.