John Joseph Burack

Optical fiber circuits

Emerging high capacity electronic systems are increasingly adopting optoelectronics as a means of surpassing the limitations of electrical interconnection. Although photonic technology has long been preferred in long-haul communications, optics is now quickly becoming a viable option for short link applications. As optical components begin to populate all levels of the system hierarchy, serious problems arise in the management of fiber cables. In this paper, we present a coordinated and manufacturable solution to this problem in the form of optical fiber circuits useful for backplane and inter-shelf communications.<<ETX>>

Enhanced moisture protection of electronic devices by ultra-thin polyimide films

Thin films of polyimide that exhibit enhanced resistance to moisture, fabricated using the Langmuir-Blodgett (LB) technique, are discussed. The adhesion strength of both LB and spin-coated films of several different polyimides, deposited on fused silica, has been measured by subjecting the films to steam or water, followed by a tape test, and monitoring changes in their ultraviolet spectra. The results demonstrate that LB films adhere better to fused silica than the spin-coated films. Measurements of the rate of water vapor transmission through Kapton sheet coated by a monolayer of any of the polyimides show that a monolayer forms a moisture barrier. On the basis of these results the electrical performance of polyimide films has been tested at 85 degrees C and 85% humidity by measuring leakage current between conducting paths under 180-V bias, using samples coated with various combinations of LB and spin-coated films. Composite films consisting of a LB monolayer either underneath or on top of a thick, spin-coated film exhibit superior electrical performance to either type of film by itself.<<ETX>>