TY - JOUR
T1 - Material properties and RF applications of high k and ferrite LTCC ceramics
AU - Matters-Kammerer, M.
AU - MacKens, U.
AU - Reimann, K.
AU - Pietig, R.
AU - Hennings, D.
AU - Schreinemacher, B.
AU - Mauczok, R.
AU - Gruhlke, S.
AU - Martiny, C.
PY - 2006/1/1
Y1 - 2006/1/1
N2 - The continuous trend in modern electronic applications towards smaller size, higher integration density and enhanced functionality requires new materials, which allow embedding passive functions into the substrate. In this paper an LTCC material system with specialized dielectric and magnetic LTCC tapes cofireable in a low-shrinkage process for RF-passive integration is reported. An LTCC dielectric with a dielectric constant of up to 80 is presented. The material is successfully used in a cofired multi-material stack to realize a fully integrated band-pass filter for Bluetooth applications of 1.3 mm3 volume. A ferroelectric LTCC ceramic with a maximum dielectric constant of 3000 is presented and the reduction of the dielectric constant to a maximum value of 1100 under constrained-sintering is discussed. Magnetic permeabilities of 14 for a NiZnCo-ferrite and 3.5 for a Ba3Co 2Fe24O41 (Co2Z) ferrite have been realized under LTCC processing conditions, with gyromagnetic resonance frequencies above 1 GHz and 3 GHz respectively. The permeability of these materials is determined for constrained and unconstrained sintering conditions. A maximum absorption of 27 dB/cm and 30 dB/cm is measured for an embedded stripline in NiZnCo- and Co2Z ferrite respectively. Two-winding planar RF-chokes in different multi-layer stacks are compared. A maximum of 14.3 nH inductance is realized for a 1.8 mm × 2 mm coil in an LTCC research pilot line.
AB - The continuous trend in modern electronic applications towards smaller size, higher integration density and enhanced functionality requires new materials, which allow embedding passive functions into the substrate. In this paper an LTCC material system with specialized dielectric and magnetic LTCC tapes cofireable in a low-shrinkage process for RF-passive integration is reported. An LTCC dielectric with a dielectric constant of up to 80 is presented. The material is successfully used in a cofired multi-material stack to realize a fully integrated band-pass filter for Bluetooth applications of 1.3 mm3 volume. A ferroelectric LTCC ceramic with a maximum dielectric constant of 3000 is presented and the reduction of the dielectric constant to a maximum value of 1100 under constrained-sintering is discussed. Magnetic permeabilities of 14 for a NiZnCo-ferrite and 3.5 for a Ba3Co 2Fe24O41 (Co2Z) ferrite have been realized under LTCC processing conditions, with gyromagnetic resonance frequencies above 1 GHz and 3 GHz respectively. The permeability of these materials is determined for constrained and unconstrained sintering conditions. A maximum absorption of 27 dB/cm and 30 dB/cm is measured for an embedded stripline in NiZnCo- and Co2Z ferrite respectively. Two-winding planar RF-chokes in different multi-layer stacks are compared. A maximum of 14.3 nH inductance is realized for a 1.8 mm × 2 mm coil in an LTCC research pilot line.
UR - http://www.scopus.com/inward/record.url?scp=28844443527&partnerID=8YFLogxK
U2 - 10.1016/j.microrel.2004.10.022
DO - 10.1016/j.microrel.2004.10.022
M3 - Article
AN - SCOPUS:28844443527
SN - 0026-2714
VL - 46
SP - 134
EP - 143
JO - Microelectronics Reliability
JF - Microelectronics Reliability
IS - 1
ER -