Advanced multilayer thick-film technology for cost-effective millimetre-wave multi-chip modules

Abstract

This paper describes the novel application of photoimageable thick film technology for the realization of multilayer millimeter-wave multi-chip modules at a low cost. The dielectric material has been characterized first time up to 110GHz with a novel technique. TFMS and CPW transmission lines have been characterized with a loss of 0.2dB/mm and 0.3 dB Imm respectively at 80GHz. High Q multilayer lumped components have been designed and modeled up to 40GHz with excellent performance. A 3GHz lumped element filter has remarkably low pass band loss of 0.3dB with high stop band attenuation (> 40 dB), and yet is highly miniaturized. Multilayer passive components have been designed and characterised up to 65 GHz and the performances are comparable to many reported results for thin film processes and even micro machined transmission lines.

Experimental study of the effect of ground width for millimetre-wave multilayer coplanar waveguides in ceramic multichip module technology

“…Using this advanced technology the thin-film microstrip and initial results for the CPW have been reported [13,15] and have successfully demonstrated a compact and complete mm-wave MCM receiver at 65 GHz integrating MMICs with other embedded passive components [8,12]. Furthermore, the technology is compatible with many fabrication processes including LTCC and thin film, and is being considered as a viable approach to realise compact and cost-effective ceramicbased microwave and mm-wave multi-chip-modules (MCMs) and SIP architectures [8,9,18,19].…”

“…Depending on the photo mask pattern the required conductor pattern (for conductor layer) or dielectric via pattern (for dielectric layer) is formed. Finally, the developed pattern is fired in the furnace at 8508C [9]. In contrast to the standard thick-film process, the photoimageable thick-film technology separates printing and pattern generation and allows independent optimisation of these two manufacturing steps, as a result, the process is highly capable of achieving fine conductor geometry, required for mm-wave circuits.…”

“…Layers of photoimageable dielectric paste were printed to form the required thickness of dielectric. The modern photoimageable thick-film technology was found to be well placed to address the lack of precision in conventional thick film technology, yet the process is straightforward and at the same time it offers low conductor and dielectric loss, good surface finish and the ability to realise a thin dielectric layer of 10 mm and fine conductor geometries of about 15 mm [9,12]. The photoimageable thick film has been used previously to successfully develop a wide range of miniaturised passive components with challenging performance up to 60 GHz [12 -18].…”

“…1 shows the cross-sectional view of a multilayer finite ground width conductor-backed coplanar waveguide (FG-CBCPW) used in this work. The test structures were fabricated using advanced photoimageable thick-film technology [8,9] on a ceramic base substrate using a conventional screen printer. Layers of photoimageable dielectric paste were printed to form the required thickness of dielectric.…”

“…Comparison of the process performance for conventional multilayer MCMs and the photoimageable thick-film MCM technology[9,10,20] Fig. 2Layout of a multilayer FG-CBCPW on advanced multilayer thick-film technology…”