High-performance ultra-miniature and thin-film transmission line capacitors

AVX Corporation offers a line of ultraminiature, thin-film transmission line capacitors for high-frequency links, DC blocking in the UHF range (300MHz-3GHz), and additional high-performance microwave and RF applications. The capacitors offer a novel MIM structure, copper traces for optimal circuit conductivity, a transmission line wire-bond pad, and a gold-metallised backside ground, and can be provided on a mixture of low-loss substrates, including quartz, glass, alumina, and silicon. The new transmission line capacitors are also offered in a broad range of capacitance values. For example, 0.3-50pF with a ±20% tolerance, and each is made using an HFSS to proactively address any electromagnetic challenges and give the highest possible RF performance and reliability.

“Our thin-film transmission line capacitors are developed using ultra-precise HFSS designs for optimised circuit conductivity and RF performance. They offer a wide range of capacitance values and several customisable features, including impedance values and substrate material and thickness, and are also gold-wire bondable and RoHS compliant, enabling their employment in a broad range of high-performance microwave and RF applications,” said Larry Eisenberger, principal technical marketing engineer at AVX.

These transmission line capacitors are offered in three standard substrate thicknesses: 5, 10, and 15mils (0.005, 0.01, 0.015") and two standard substrate widths: 20 and 40mils (0.02-0.04") and provide design-dependent lengths defined by transmission line dimensions. Average lengths are commonly in the realm of 20-80mils (0.02-0.08"), but lengths up to and beyond 320mils (0.32") are not uncommon.

The range is rated for up to 100V, has specific capacitance values covering 50-100pF/mm2, a dissipation factor of less than 0.1%, and a TCC value of ±60ppm/C, and exhibits 50Ohm standard impedance;. However, actual maximum capacitance values also depend on transmission line dimensions.

These transmission line capacitors are also RoHS compliant and are tested to MIL-STD-883-2011.8 for bond strength, MIL-STD-883-2018 for shear strength, and MIL-STD-202-108 for lifetime. Packaging options include antistatic waffle pack, tested but un-diced, and tested and diced on tape.