MICROWAVE AND MM-METER WAVE APPLICATIONS: A NEW CHALLENGE FOR CERAMIC THICK FILM TECHNOLOGY

摘要

Applications for microwave circuitry are in rapid expansion, particularly in the field of portable communications systems, and the operating speeds of digital integrated circuits (ICs) continue to increase, creating the need for suitable interconnect materials, integrated components and packaging solutions. Several papershave been written in the last five years to describe the characterization and the performance of ceramic thick film in high frequency applications and to compare these properties with other interconnect technologies such as thin film and high performance PWBs under the same test conditions. This paper will discuss briefly such performances and review the reasons for the choice of thick film in some recent microwave and mm-wave modules for wireless communications and airborne radar applications, where the operating frequencies are in the range of few GHz. In particular three different modules will be discussed in this presentation and some details of their design and construction will be reviewed. The first two examples under consideration will describe two converter modules, one microwave Down-Converter operating in the 7-8.5 GHz frequency range and one mm-meter transmitting Up-Converter, operating at a frequency of 23 GHz; both modules have been manufactured using thick film multilayer materials on alumina substrates and the first module will also use thick film inks for integrating passive components. The other application will describe a highly integrated mm-wave module operating in the frequency range of 27 to 30 GHZ using LTCC multilayer substrate and metallised plastic covers. The paper will also review in some detail the packaging solutions adopted in each specific case, including some information about the choice of materials, components and interconnect technologies and some cost advantages linked to the technological choice.