Thin-Film Caps Vie For Microwave/RF Employment

AVX Corporation’s latest line of ultraminiature, thin-film transmission line capacitors are viable for high-frequency links, DC blocking in the UHF range (300 MHz to 3 GHz), and other high-performance microwave and RF applications. The components have a novel metal-insulator-metal (MIM) structure, copper traces for optimal circuit conductivity, a transmission line wire-bond pad, and a gold-metallized backside ground, and can be supplied on a variety of low-loss substrates, including quartz, alumina, glass, and silicon. They are also available in a wide range of capacitance values: 0.3 pF to 50 pF with a ±20% tolerance, and each is made using a high-frequency structure simulator (HFSS) to proactively address any electromagnetic challenges.  

 

The transmission-line capacitors are available in three standard substrate thicknesses: 5, 10, and 15 mils (0.005, 0.01, 0.015”) and two standard substrate widths: 20 and 40 mils (0.02 to 0.04”) and have design-dependent lengths determined by transmission line dimensions. Average lengths are generally in the realm of 20 to 80 mils (0.02 to 0.08”), but lengths up to and beyond 320 mils (0.32”) are not altogether uncommon.

 

The range is rated for up to 100V, has specific capacitance values ranging from 50 to 100 pF/mm2, a dissipation factor of less than 0.1%, and a TCC value of ±60 ppm/ºC, and exhibits 50Ω standard impedance; although, actual maximum capacitance values also depend on transmission line dimensions. Custom impedance values, substrate materials, and substrate thicknesses are available upon request. For more information, checkout the thin-film transmission line capacitor datasheet, email [email protected], and/or call 864-967-2150.