Single-mode optoelectronic communication is the technology of choice in the telecommunication industry, due to the long distances and high data rates that are achievable. These benefits are now being exploited in the field of data communications. However, the demands of the data communication application are somewhat different from those of telecommunication. This paper discusses these differences.

Typical optical performance parameters for the data link are also considered. The two most important of these parameters are the laser safety limit and the minimum launched power. The methodologies which assure both of these parameters are presented.

The physics of single-mode fiber-to-fiber and laser-to-fiber coupling is reviewed, including an overview of various theoretical models which have been used. Results of ongoing experimental studies are presented and compared to a theoretical model. Discrepancies between the experimental results and the model are discussed.

The development of secondary phases due to additions of Y2O3 during sintering of aluminum nitride was studied. Depending on the heat treatment conditions and the amount of Y2O3 added, different proportions of AlYO3, Al5Y3O12 and Al2Y4O9 were found at the grain boundaries. Temperatures ≳1850°C also resulted in loss of Y2O3 and/or Y-aluminate, yielding some γAl2O3. The mechanical properties and the thermal conductivity of the sintered product were observed to be dependent on the grain boundary phase constitution and hence the specific heat treatment condition.

In this paper we report on a high rate (˜ 100 nm/min) aluminum nitride (AIN) deposition process, as well as several novel applications of AIN thin films for microelectronics and optoelectronics applications. Surface morphology and chemical composition, etchability, etch selectivity to oxide, and step coverage at various deposition temperatures have been investigated by atomic force microscope (AFM), scanning electron microscope (SEM) and Auger spectroscope (AES). In addition, for the first time, chemical mechanical polishing (CMP) of AIN films has been carried out and a polishing rate of 270 nm/min has been achieved. Results of several novel processes involving AIN as an etchstop layer in microelectronics and as an optical interconnection in opto-electronics will be presented.

Residual stresses that develop in metal/ceramic bonded systems due to thermal expansion mismatch have been calculated using finite element modelling and measured experimentally using a simple bilayer strip. Bending in the strip occurs during cooling due to the stress asymmetry. Residual stresses are calculated by measuring the deflection of the strip and the temperature at which the strip is flat. Various compositions of both copper and nickel pastes, with and without glass and other second phase additions were evaluated on glass-ceramic. The effects of further processes, e.g. thermal cycling, brazing and plating, are also reported in this work.

A technique combining the use of microhardness indentations and an aluminum etch decoration process has been developed to measure the relative ability of polymer coatings to protect an integrated circuit (I.C.) device surface from mechanical damage. A threshold for inducing a crack in a passivated silicon surface was measured by applying a grid of indentation loads and measuring the load at which the aluminum etchant revealed damage in the passivation. A polyimidesiloxane and two polyimide materials, with widely different elastic moduli, were tested.

The ability of a coating to protect the chip surface was found to increase with increasing compliance of the film. The materials with the higher threshold loads had lower elastic moduli and allowed greater indenter penetration depth for a given load. Our finite element mechanical model supports the hypothesis that the stress generated by the indenter tip is absorbed and distributed by the lower modulus materials. The stress is transferred to the passivated silicon in the case of the higher modulus film, leading to damage at lower loads.

Passive alignment techniques using area array solder joints are currently under investigation as a cost effective method of achieving electro-optical interconnects in electronic packages. Several investigators have developed models that describe the shapes of and forces produced by the liquid solder drops during reflow. These models are reviewed to provide a scientific basis for the application of such techniques.