Epoxies for OptoElectronic Packaging; Applications and Material Properties

Abstract

Epoxies are used in the packaging and assembly of three opto-electronic devices, including Fiber Optics, LEDs, and LCDss. In fiber optics, you need epoxy for the cable and for the opto-packaging. The fiber optic components are usually packaged in hybrid technology, which mean several micro-electronic grade joining materials will be used. For LEDs, the silver epoxy is needed for both electrical and thermal properties. Optically clear epoxy is used for the potting, molding, or encapsulation of the LED. In LCDs, there are many different applications of epoxy of which 2 are presented. These include silver filled for interconnecting the ITO conductive layers to the circuitry on the substrate, while the second is the optical epoxy for making the glass sandwhich. This paper will discuss the epoxies which are used, the key design attributes which make them ideal, and the processing of them for assembly and manufacture. Analytical techniques for characterization and optimization of the epoxy properties will be discussed. Material properties such as Tg, outgassing, thermal conductivity, thermal resistance, hermeticity, strength, and fluorescence will be the focal point of the discussion.