NIST researchers characterize tile temperature-dependent dielectric properties of polymer materials to aid the electronics industry. (News Briefs).NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. staff members have completed dielectric measurements Dielectric measurements Measurements of the dielectric properties of a material, which are characterized by its complex relative permittivity εr. on a selection of plastic materials. The goal of the research was to obtain well-characterized, variable temperature measurements on a wide array of polymer materials and to develop new characterization metrology. Low-loss plastics are widely used in the microelectronics industry; temperature-dependent measurements are crucial for accurate modeling and design. For example, printed wiring boards generate heat as the computer dissipates energy, so it is very important to know the temperature-dependence of the permittivity Permittivity A property of a dielectric medium that determines the forces that electric charges placed in the medium exert on each other. If two charges of q1 and q2 coulombs in free space are separated by a distance r of the wiring board. The features that make these measurements unique include the wide array of materials, the broad temperature range, the use of very precise temperature-dependent thermal data. These measurements required a detailed uncertainty analysis which was lacking in the literature. The materials in the study were selected on the basis of utility in microelectronics applications. These plastics included commercially available materials such as Teflon, Rexolite, nylon, FEP See front end processor. , polyethylene, polysulfone, and others. The temperatures spanned were from -150 [degrees]C to 150 [degrees]C, the measurement frequency was 10 GHz, and the measurement fixture was a TE0l dielectric resonator A dielectric resonator is an electronic component that exhibits resonance for a narrow range of frequencies, generally in the microwave band. The resonance is similar to that of a circular hollow metallic waveguide, except that the boundary is defined by large change in . Literature values for the temperature-dependent thermal expansion thermal expansion Increase in volume of a material as its temperature is increased, usually expressed as a fractional change in dimensions per unit temperature change. coefficients were used in the study. The environmental chamber used to achieve the temperature dependence has bulkhead adapters on the sides for insertion of coaxial feeds for the cavity. The chamber was purged with nitrogen gas to reduce oxidation and water vapor. CONTACT: Jim Baker-Jarvis, (303) 497-5621; jjarvis@boulder.nist.gov. |
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