DIE BONDING OF DIODE LASERS

Abstract

<p>An examination of the die bonding of semiconductor diode lasers is presented. The effects of changing a number of bonding parameters such as reflow time, reflow temperature, and cooling rate on InP-based diode laser chips are investigated. Lasers bonded with both preform solder and pre-deposited solder are explored. It is also observed that stress relaxation occus in die bonds of diode lasers after a time period of hundreds of hours. A finite element method model that iteratively fits to degree of polarization of photoluminescence data is presented. It is shown how this model is used to determine components of stress and strain owing to die bonding at the facet of diode lasers. The model is shown to be capable of helping to characterize die bonds. The effect of die bonding induced strain on the spectra of distributed feedback diode lasers is also investigated. Bonding strain effects the in situ grating in distributed feedback lasers which manifests as changes in the modes of the output spectrum and the stopband width. As well, it is observed that the lasting mode can flop from one side of the stopband to the other upon bonding and this effect is successfully modelled using a DFB laser model.</p>