Broadband complex permittivity measurements of microwave interconnects and bonding materials

This paper presents a systematic study of the complex dielectric permittivity of two interconnect and bonding materials that are used in high frequency multi-chip modules. The materials are characterized in the Q-band, V-band and W-band frequency ranges using a broadband quasi-optical millimeter wave spectrometer with a backward wave oscillator (BWO) as a non-destructive high-power tunable source of coherent radiation. The real and imaginary parts of the dielectric permittivity and loss tangent have been accurately calculated from the transmittance spectra.