Basic study of proper global wiring structure for advanced system in package

This paper is investigated on the global wiring structure for next-generation SiP structure (target wire length =10mm, target frequency =10GHz, without repeater) by using electromagnetic analysis and simulation. Toward this target, we decide to attain signal attenuation smaller than -10dB at 30GHz (3rd harmonics). For this purpose, we propose that the attenuation of signal has been improved by making structure of global wiring into strip-line + coplanar structure. As a result, we find the condition (wire thickness and width 1.2 mum, distance between wires and insulator thickness 2.4 mum), which can transmit the signal (|S₂₁| > -10dB, |S₃₁|, |S ₄₁| < -30dB at 30GHz). Furthermore, the feasible region among characteristic impedance, wire pitch and, attenuation of signal is made clear by using above results. This result means that moving of the global wirings on SiP with 10GHz digital signal from the device to the interposer circuit board will be needed in near future