High frequency characterization of embedded film capacitor and application to multi-layer package

Abstract

In modem high performance digital system, the distribution of power and the suppression of noise are major design issue. As the CMOS technologies are advanced, the design of stable power distribution system becomes more difficult because of low noise margin diminished by the increased operating frequency and total power and the decreased supply voltage of the system. Major obstacle to the stable power distribution system is the simultaneous switching noise (SSN) introduced by the sudden current flow through the inductive power/ground system within very short time period. To suppress the SSN, power/ground network impedance should be kept low at all frequencies where current transients exist. Until now, the discrete decoupling capacitors are usually adopted for the stable because it can provide low inductive current path to the system. In general, from the frequency of 100MHz, the power/ground impedance is dominated by its inductive nature. Therefore, as the clock frequency and its harmonics are increased over GHz frequency range, the discrete decoupling capacitor is no longer effective because of its inherent large inductance given by the capacitor itself, the mount pad, and the power/ground trace and via. In fact, there are continuous efforts to reduce the parasitic inductance of the capacitor itself such an inter-digitated capacitor (IDC), a low inductance chip capacitor (LICC), and a low inductance capacitor array (LICA). But, a large amount of inductance introduced by the mount-pad, the power/ground trace, and the power/ground via still exist and limit the decoupling performance at the high frequency range over GHz. Thank to its low inductive property unlike a high inductive discrete decoupling capacitor, an embedded film capacitor becomes a promising component for the power distribution system of the future high performance system. It can provide very low inductive behavior given by removing the mount-pad and traces and reducing the length of the power/grou...