Effect of substrate on reliability and antenna indicator parameters of Cu based patch antenna

This work investigates the reliability of copper thin films on various substrates such as ceramics, thin glass and polymer in terms of electromigration behaviour. Copper thin film is used to produce a 10 GHz patch antenna for wireless sensor applications. Low temperature co-fired ceramics (LTCC), Al₂O₃-ceramic, thin glass and Liquid crystal polymer (LCP) are used as substrates. The effect of substrate on Cu metallization and on antenna indicator parameters such as resonance frequency, input reflection coefficient, bandwidth and gain are investigated. Afterwards the median time to failure (MTF) of copper lines on the above mentioned substrates are investigated. Important parameters for the electrical migration characterisations, such as the activation energy and the current density exponent, are extracted from these measurement results.