Permittivity Reduction and Surface Modification by Porosification of LTCC

Abstract

The wet-chemical porosification of low temperature co-fired ceramics is investigated with respect to the resulting permittivity reduction and surface modification. Therefore, four commercially available tapes are characterized by means of a detuned ring resonator as well as by chromatic white light and scanning electron microscopy analyses. The results show a technically relevant permittivity reduction of about 15% to 18% measured at a frequency of 44 GHz. Thereby, the vertical distribution of the air, embedded by the porosification, is of high influence. The achievable reduction in permittivity strongly counteracts the surface quality, which is necessary for applying high quality metallization lines.

The wet-chemical porosification of low temperature co-fired ceramics is investigated with respect to the resulting permittivity reduction and surface modification. Therefore, four commercially available tapes are characterized by means of a detuned ring resonator as well as by chromatic white light and scanning electron microscopy analyses. The results show a technically relevant permittivity reduction of about 15% to 18% measured at a frequency of 44 GHz. Thereby, the vertical distribution of the air, embedded by the porosification, is of high influence. The achievable reduction in permittivity strongly counteracts the surface quality, which is necessary for applying high quality metallization lines.