A review of non-hermetic optoelectronic packaging

Abstract

This paper is a summary of a literature survey done on non-hermetic optoelectronic packages focusing on the cost and reliability aspects. The development of reliable non-hermetic lasers would not only lead to the elimination of the costs specifically associated with hermetic packaging but also lead the way for possible revolutionary low-cost optoelectronic packaging technologies. The paper starts with an introduction to the concept of hermeticity in optoelectronic packages, followed by a detailed review of the reliability issues and failure mechanisms observed in non-hermetic packages when compared to their hermetic counter parts. A hermetic seal in electronic packages is used to prevent the entry of air, foreign gases, contaminants, and most importantly moisture. To seal a package hermetically is particularly challenging and expensive. There are various techniques that have been investigated, to improve the reliability of non-hermetic packages. A few are discussed here such as facet passivation type, choosing a better optical glass and encapsulation techniques. Also accelerated testing is discussed. Some of the most common and important failure mechanisms like popcorn failure, adhesive degradation, laser misalignment and epoxy swelling are discussed.