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The development of a molded-plastic packaging technology for optical data link transceivers is discussed. The technology, which integrates both optical and electrical components in a single package, was prototyped using design-for-simplicity techniques for an optical transceiver for fiber distributed data interface applications. It involves overmolding for sealing the package and aligning the optical ports as well as two-step transfer molding for internal shielding and intermediate integrated circuit testing.

The molecular orientation and disclination defects in injection molded bulk samples of liquid crystal polymers have been revealed by transmission electron microscopy (TEM). Using a recently optimized lamellar decoration and etch technique for use with poly(benzoate-co-naphthoate), we have studied in detail the skin-core morphology produced by realistic injection molding processing. In the skin, the director is observed to be highly aligned along the flow direction, and the defect density is very low (10 [cm.sup.-2]). In the core, however, the defect density is six orders of magnitude greater, and the directo lies predominantly in the plane defined by the flow and neutral directions. The flow during processing is turbulent, giving rise to distinct morphological features and disclination clusters. When the material is filled at 20% volume fraction with long glass fibers, the molecular and filler orientations are nearly parallel. Dimensional precision also correlates with the morphology and improves with increasing core fraction., INTRODUCTION Liquid crystalline polymers (LCPs) possess a number of extraordinary properties that make them attractive for injection molding (1). They have extremely low viscosities, which make them especially suitable to [...]