Resin coated copper capacitive (RC3) nanocomposites for multilayer embedded capacitors

This paper discusses thin film technology based on resin coated copper capacitive (RC3) nanocomposites. In particular, we highlight recent developments on high capacitance, large area, thin film passives, their integration in printed wiring boards (PWB), system in package (SiP) and chip package substrates and the reliability of the embedded capacitors. A variety of RC3 nanocomposite thin films ranging from 2 microns to 50 microns thick were processed on PWB substrates by liquid coating or printing processes. SEM micrographs showed uniform particle distribution in the coatings. The electrical performance of composites was characterized by dielectric constant (Dk), capacitance and dissipation factor (loss) measurements. Nanocomposites resulted in high capacitance density (7-500 nF/inch²) at 1 MHz. The manufacturability of these films and their reliability has been tested using large area (13 inch times 18 inch or 19.5 inch times24 inch) test vehicles. Reliability of the RC3 nanocomposite was ascertained by IR-reflow, PCT (pressure cooker test) and solder shock. As a case study, an example of RC3 based multilayer embedded capacitor construction for a flip-chip plastic ball grid array package with a 300 mum core via pitch is given. This effort is an integrated approach centering on three interrelated fronts: (1) materials development and characterization; (2) fabrication, and (3) integration at the device level.