Non-hermetic techniques for low cost, high performance, opto-electronic component assembly

The packaging of opto-electronic components for telecommunications purposes has traditionally required an hermetic approach using precision metal packages. This imposes a high cost penalty on the components and there is the added yield problem of hermeticity failures at, what is normally, the final assembly process. In this paper some enabling technologies are investigated which can, potentially, reduce costs while still maintaining high performance. The use of visible light cured resins to simplify assembly processes is a potentially powerful technique. The direct attachment of the optical fibre to the active area of the device, of both lasers and photodiodes, will be reported, allowing a range of low-cost package styles. Additionally consideration will be given to any degradation of adhesive within the optical path. The use of silicone gel coatings for opto-electronic components will be presented. These materials in their purest form offer a number of highly useful properties and are a much cheaper alternative to the hermetic package, particularly for arrays of devices. PIN photodiodes coated in these gels have been subjected to damp heat stress lifetest and the results obtained will be discussed. A service life of greater than 60 years is indicated. Gallium Arsenide lCs have also been gel coated and have shown no sign of degradation over the duration of the test. Semiconductor lasers, conventionally housed in hermetic packages have exhibited the potential to operate satisfactorily, when gel coated, with long lives under normal operating conditions. The results for damp heat stress tests, on gel coated lasers and PINs will be reported and the necessity to run opto-electronic devices in hermetic environments reviewed.