[Zurück]

A. Bittner, U. Schmid:
"Impact of Metallization Properties on the High Frequency Performance of Coplanar Waveguides on LTCC";
Poster: IMAPS - Electronic Devices and Systems, Brno, CZ; 28.06.2012 - 29.06.2012; in: "Proceedings Electronic Devices and Systems", (2012), S. 224 - 228.

In this study the high frequency performance of conventional screen printed
gold and silver thick films is compared with that of sputter deposited thin films.
As substrate LTCC DP951 is applied. For evaluation purposes the transmission
dispersion parameter |S21| is measured for coplanar waveguides in the range
between 20 to 40 GHz. The damping factor α at 20 GHz ranges from
0.01213 dB/mm for Au thin films to 0.00399 dB/mm for Ag thick films. For
both metal systems the thick film metallization shows a lower attenuation but
with lower values in the case of silver. This is mainly due to the lower film
resistivity compared to that of gold. The good performance of the thick films is
attributed to the higher layer thickness although the conductivity is lower
because of e.g. glass-frit content in the screen printing pastes as the thin film
thickness of 1 μm is about half the skin depth for gold and silver at 20 GHz.
Thermal annealing reduces the damping effects in the thin film metallization
systems as grain growth occurs thick films stay almost unaffected even when
sintered at even elevated temperatures.

In this study the high frequency performance of conventional screen printed
gold and silver thick films is compared with that of sputter deposited thin films.
As substrate LTCC DP951 is applied. For evaluation purposes the transmission
dispersion parameter |S21| is measured for coplanar waveguides in the range
between 20 to 40 GHz. The damping factor α at 20 GHz ranges from
0.01213 dB/mm for Au thin films to 0.00399 dB/mm for Ag thick films. For
both metal systems the thick film metallization shows a lower attenuation but
with lower values in the case of silver. This is mainly due to the lower film
resistivity compared to that of gold. The good performance of the thick films is
attributed to the higher layer thickness although the conductivity is lower
because of e.g. glass-frit content in the screen printing pastes as the thin film
thickness of 1 μm is about half the skin depth for gold and silver at 20 GHz.
Thermal annealing reduces the damping effects in the thin film metallization
systems as grain growth occurs thick films stay almost unaffected even when
sintered at even elevated temperatures.