Colloidal processing of polymer ceramic nanocomposite integral capacitors

• Published in: IEEE transactions on electronics packaging manufacturing Vol. 26; no. 2; pp. 100 - 105
• Main Authors: Windlass, H., Raj, P.M., Balaraman, D., Bhattacharya, S.K., Tummala, R.R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2003; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Capacitance; Capacitors; Ceramics; Composite materials; Design engineering; Dielectric constant; Dielectric materials; Dielectric, amorphous and glass solid devices; Dispersions; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Electrostatics; Exact sciences and technology; Fabrication; Magnesium; Microelectronic fabrication (materials and surfaces technology); Nanomaterials; Nanostructure; Polymers; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Temperature; Titanium compounds; Performance evaluation; Waveform; High density; Lead titanates; Composite material; Dielectric ceramics; Microelectronic fabrication; electrostatic; Nanocomposite; colloidal; Permittivity; Electrical characteristic; Ultrathin films; nanoceramics; Barium titanate; Multichip module; Lithography; Dielectric properties; Lead compound; Polymer; System on a chip; Ceramic capacitor; Colloidal dispersion; Experimental result; SOP; Electrophoretic mobility; integral capacitors; Capacitance; Measurement method; dispersion; Magnesium compound; PMNPT
• ISSN: 1521-334X; 1558-0822
• DOI: 10.1109/TEPM.2003.817719

Polymer ceramic composites form a suitable material system for low temperature fabrication of embedded capacitors appropriate for the MCM-L technology. Improved electrical properties such as permittivity can be achieved by efficient filling of polymers with high dielectric constant ceramic powders such as lead magnesium niobate-lead titanate (PMN-PT) and barium titanate (BT). Photodefinable epoxies as the matrix polymer allow fine feature definition of the capacitor elements by conventional lithography techniques. The optimum weight percent of dispersant is tuned by monitoring the viscosity of the suspension. The dispersion mechanism (steric and electrostatic contribution) in a slightly polar solvent such as propylene glycol methyl ether acetate (PGMEA) is investigated from electrophoretic measurements. A high positive zeta potential is observed in the suspension, which suggests a strong contribution of electrostatic stabilization. By optimizing the particle packing using a bimodal distribution and modified processing methodology, a dielectric constant greater than 135 was achieved in PMN-PT/epoxy system. Suspensions are made with the lowest PGMEA content to ensure the efficiency of the dispersion and efficient particle packing in the dried film. Improved colloidal processing of nanoparticle-filled epoxy is a promising method to obtain ultra-thin capacitor films (<2/spl mu/m) with high capacitance density and improved yield. Capacitance of 35 nF/cm/sup 2/ was achieved with the thinnest films (2.5-3.0 /spl mu/m).