Here is the abstract you requested from the CICMT_2009 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Fabrication of Capacitor Embedded LTCC Substrate for RF Applications|
|Keywords: LTCC, CEL, EMBEDDING|
|A highly integrated and miniaturized RF module based on LTCC(Low Temperature co-fired Ceramic), Capacitor Embedded LTCC, CEL, has been proposed. And via type MLCC as decoupling capacitor for noise suppression performance also has been proposed to embed in it. To comply with recent demands for RF applications, the LTCC substrate which is embedded high capacitance (>20nF) of via type MLCC in the cavity is proposed. It is smaller than ordinary LTCC substrate size for RF Module. The via type MLCC using high K layer less than 10um thick green tape could be sintered in the air instead of reduction ambient to co-fire with LTCC as embedded. Due to its short distance from IC power pin to decoupling capacitor, ESL (Equivalent Series Inductance) is much lower than surface mounted type of capacitor, and so, SSN (Simultaneous Switching Noise) could be reduced significantly. Now a days non shrinkage process of LTCC has been used for expecting no shrinkage in the lateral dimensions. We used alumina green tape as sacrificial layer. But the cavity shape used to be distorted during sintering due to the stress difference between inside cavity and outside cavity when shrinkage is generated. It could be controllable by co-firing two different LTCC materials in a way that the sintering starts at different temperature. The matching quality at the electrode on the via type MLCC-the electrode on the CEL interface was acceptable for electrical connection. Reliability of CEL was evaluated experimentally. Considering the affordability and design flexibility, we anticipate the proposed CEL is not only suitable for RF module but also a promising solution for automotive or any other applications using LTCC as substrate where the chip embedding is demanded.|
|Ki Pyo Hong, Manager
Suwon, Kuunggi-Do 442-743,