Here is the abstract you requested from the rf_2008 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Liquid Crystal Polymer Packages for Microwave Applications|
|Keywords: Liquid Crystal Polymer, microwave packaging, QFN|
|These new plastic air cavity packages are pre-molded from Liquid Crystal Polymer (LCP) to produce high performance and cost effective packages for microwave applications. The properties of LCP are blurring the boundaries between what is thought of as “plastic” versus the glasses, metals and ceramics used for semiconductor packaging. The very low moisture permeability of LCP packages provides excellent environmental protection for die resulting in near hermetic packages. LCP dielectric has a low microwave loss tangent which, when combined with low resistivity conductors and package bases, produces packages with outstanding microwave performance. The molded LCP dielectric of the package is a very tough material with a stable dielectric constant over temperature and frequency. The combined mechanical, thermal and electrical performance combined with a 3 dimensional injection molding technology comes together to provide innovative and cost effective solutions. Leaded packages can be manufactured with a separate base and sidewall for high temperature eutectic die attaches processes. The inherent flexibility of the system allows a wide choice of materials for the package base ranging from high thermal conductivity copper to CTE controlled metals or composites or even ceramics. This also means that the base and leads of the package can be plated separately with the most suitable and cost effective choice of plating types and thicknesses. A number of microwave packages will illustrate the design and material options inherent in this state-of-the-art packaging technology. Quad Flat No-lead (QFN) air cavity packages can also be manufactured with this technology. QFNs can be outstanding solutions for microwave and millimeter applications with low loss air cavity design and compact footprints. A solid metal die pad results in excellent thermal performance and electrical grounding. Data will show examples of package performance through millimeter wave frequencies.|
|John W. Roman, Chief Technical Officer
RJR Polymers Inc.