Design, simulation and measurement techniques for embedded decoupling capacitors in multi-GHz packages/PCBs
Embedded capacitor is a better solution than surface mount capacitors for decoupling in a high speed, high performance packages/PCBs. Our study has showed that with conventional approaches, the embedded capacitor for decoupling in power delivering network can work from 100 MHz to 1 GHz systems. Pushing the operating frequency over 1 GHz is a challenge for system designers. This paper discusses the embedded decoupling capacitor design for multi-GHz systems through principles, simulation, measurement error, and error elimination.
Through Co-design to optimize power delivery distribution system using embedded discrete decoupling capacitor
As clock speeds increase into the gigahertz regime and rise times decrease into the pico-second regime, the interaction between capacitors and power/ground planes of a package, or board on which they are mounted becomes vitally important to the performance of a power delivery system. Capacitors pose the biggest challenge for integration in packages due to the large capacitance required for decoupling high performance circuits. Although Embedded Passive Substrate (EPS) using thin-film technique was addressed and developed, the actually application without substrate packaging layer increased is difficult. An Embedded Discrete Passive Substrate (EDPS) technology is increasingly drawing attention because of its potentials in addressing system cost reduction by offering smaller size form factor with high level of integration in packaging. In this paper, a embedded discrete capacitor structure was designed and fabricated on organic substrate packaging. Through early engagement and optimization on substrate packaging design, the embedded discrete capacitors could improve the electrical performance of core power distribution system. To validate the feasibility, a test substrate packaging is built. In addition, the simulation results of core power distribution system with EPDS and Copper Wire-Bond (CWB) on time-doamain and frequency-domain demonstrate the electrical performance is better than others..
Correlation between Fluoride Release, Microhardness and Solubility of High viscosity Glass Ionomers
This study was to measure and compare the amount of fluoride, microhardness and solubility of high viscosity glass ionomer and resin-reinforced glass ionomer during 84 days. Fuji IX GP EXTRA, Fuji IX GP, Fuji II LC and FiltekTM Z350XT stored in deionized water for 84 days to measure fluoride release, microhardness and solubility. As a result of measurement of fluoride release, all the glass ionomers showed the highest amount of fluoride release on day 1 and gradually decreased. Fuji IX GP EXTRA showed the highest amount of fluoride release and cumulative release. And Fuji IX GP and Fuji II LC showed no significant difference. Microhardness measurements showed that all experimental groups decreased 1 day after exposure to water. After 84 days, microhardness showed no significant difference between Fuji IX GP EXTRA and Fuji IX GP, and Fuji II LC was the lowest. In the solubility measurement, Fuji IX GP EXTRA, Fuji IX GP, and Fuji II LC increased rapidly to 21 days. After 21 days, there was no significant difference in the three groups. As a result, short term fluoride release affects solubility and microhardness, but long term fluoride release has no correlation. Through this study, the amount of fluoride, microhardness, and solubility of various glass ionomers were evaluated, and these properties could be applied clinically.