Thermal Analysis of a Vaporization Source for Inorganic Coatings

Abstract

A thermal analysis of a conventional vaporization source by finite difference methods, including experimental validation, is presented. Such a system is common to industries whose chief concern is the precipitation of inorganic coatings. Both the physical and the model systems are comprised of a number of layers, or strata, arranged in a rectangular configuration. The model strata represent the component and deposition materials of the physical vaporization source. The symmetry and simplistic geometry of the operational source permit the use of a two-dimensional model, thereby neglecting gradients in the third dimension. The production unit, as well as the numerical model, experience various modes of heat transfer, including radiation, convection, conduction, internal generation, and phase change. Moreover, the system inputs are time-dependent.

The numerical model is subsequently compared to and validated against both simplistic case studies and the physical production system. Data collected from the operational deposition source is examined and analyzed in comparison to corresponding information generated by the numerical model. Sufficient agreement between the data sets encourages the utilization of the numerical model as a practical indicator of the subject system's behavior.

Finally, recommendations for modifications to the physical vaporization source, yielding practical improvements in temperature uniformity, are evaluated based on the predictions of the validated numerical model. The goal is the attainment of an ideally uniform temperature distribution that would correspond to highly desirable performance of the process vaporization system.