PACKAGING ON LTCC: MICRORELAY AND RFID L. Malatto, A. Lozano, L. Fraigi, D Lupi
Centro de Investigación y Desarrollo en Telecomunicaciones, Electrónica e Informática – CITEI Instituto Nacional de Tecnología Industrial – INTI
Av. Gral Paz 5445, (B1650 KNA) San Martín, Pcia. Buenos Aires, Argentina Laura@inti.gov.ar
Summary: We present the first results of MEMS packaging integrated with LTCC (Low Temperature Co-fired Ceramics) technology. Two cases were implemented: a packaging of a MEMS microrelay with lateral contact structures driven by electrostatic actuators, and an integrated antenna for commercial RFID (Radio Frequency Identification), which is under development.
Keywords: MEMS packaging, LTCC, microrelay, RFID
1. INTRODUCTION
Low Temperature Co-fired Ceramic (LTCC) is well known as an appropriate material for multilayer packaging. This material joined to thick film technology results in an interesting field for MEMS applications.
LTCC tape materials for 3D structures using multilayer have many benefits for packaging silicon based MEMS components. Cavities structures, in which the MEMS can be bonded and hermetically sealed, and a good match of thermal coefficient of expansion (TCE) between ceramic and Si are some advantages of LTCC technology [1].
In this work we present LTCC packaging for two different applications, a MEMS microrelay developed on epitaxied SOI [2] and antennas for commercial Radio Frequency Identification (RFID).
2. EXPERIMENTAL
Two models of packaging for the SOI microrelay prototypes were performed: a top contact design with all electrical connections at one side of the packaging, and a bottom contact design using through holes. Twelve layers were necessary to achieve a properly package.
DuPont LTCC Green Tape 951 AT and DuPont 6148 silver thick film paste were used, with screen printing technique. Cavities and through holes were done and separately lamination steps were performed in order to obtain an appropriate structure. Lamination pressure was of 1 kg.mm-2 at a temperature of 100°C, applied during 3 minutes for each lamination procedure. Typical firing profile for LTCC was applied and a shrinkage value of 14% in x-y direction was obtained.
MEMS microrelay dies were attached to LTCC package with Dow Corning 7920 material. Fig.1 shows first prototypes of MEMS packages obtained with LTCC multilayer ceramic technology.
Two models of LTCC integrated antennas for commercial RFID were designed. EM-Microelectronic devices for low (125 kHz) and high (13.56 MHz) frequencies were used. First antenna, named multi loop (ML), is a 2D-structure flat square spiral coil. The other design, named uni loop (UL), is a multi layer square loop in a 3D-structure. Fig. 2 shows a ML antenna, at left, and a UL with 2nd level packaging (right).
Fig.1: MEMS microrelays prototypes into LTCC package. a) Top connection design. b) Bottom
connection design
Fig.2: ML and UL antenna with RFID 2nd level packaging
3. CONCLUSIONS
Two examples of LTCC packaging application were performed. Microrelay prototypes with different geometrical connections were presented. Two antennas for RFID application are under development. 4. REFERENCES
[1] M. R. Gongora-Rubio, P. Espinoza-Vallejos, L. SolaLaguna, J. J. Santiago-Avilés, “Overview of low temperature co-fired ceramics tape technology for meso-system technology (MsST)”, Sensors and Actuators A 89, pp. 222-241, 2001.
[2] A. Lozano, L. Malatto, L. Fraigi, D. Lupi, “Testing of a MEMS SOI microrelay”, 5th IEEE Latin-American Test Workshop LATW 2004, Digest of papers, pp. 123-126, 2004.
Ver+/-
