Enabling materials for wireless Multilayer Ceramic Integrated Circuit (MCIC) applications

The multilayer ceramic technology associated with the development of ceramic dielectrics which may be cofired with high conductivity metals such as Ag or Cu is enabling the fabrication of multilayer ceramic - metal structures which can integrate many of the radio frequency (RF) functions generic to consumer wireless products Multilayer Ceramic Integrated Circuits (MCIC). However, the unique requirements of these battery operated products imposes significant challenges on the traditional low temperature cofired (LTCC) materials systems to achieve low electrical losses and frequency temperature stability for the RF signals employed in these applications. The important properties of the MCIC materials system and the impact of using material systems with these properties to increase the functionality of MCIC RF wireless devices will be discussed. This paper also highlights the results related to the development of a lead (Pb) free, low fire (850-900 degrees C) ceramic RF dielectric tape and metal system with low dielectric loss and a temperature coefficient of capacitance tailored to achieve a low temperature coefficient of frequency. The properties of a specially formulated capacitor paste with high Q that is cofirable with the tape system will also be presented.