Electrothermal Analysis Of High Speed Circuits And Package

"Smaller and faster" becomes the chief demands in today’s electronic design, whichtranslate into high power densities, higher operating temperatures and reducedperformance. Power consumption and heat problems seriously affect performance andreliability of integrated circuits. Research shows that more than50%of chip failures arecaused by overheating circuit structures. Thermal predict and analysis technology arebecoming more important in high speed circuit design. The heat generation raises theoperating temperature while the rise of the temperature affects the power generation,which may exacerbates the circuit performance. Hence, accurate estimation of electricaland thermal behaviors of interconnects become one of the critical issues of IC design.As CMOS technology has scaled rapidly for decades, power dissipation hashistorically increased proportionately to increasing transistor density and switching speeds.However, with the minimum feature size of the transistor entering the nanometer regime(<100nm), leakage power has become a significant fraction of the overall chip power.And it has strong positive correlation with the temperature, which may exacerbate thecircuit performance. In this paper, temperature effects on MOSFET power dissipation arediscussed and an iteration method with electrothermal coupling effect taken into account isproposed in order to estimate the steady-state temperature field. Simulation results revealthat the proposed scheme has rapid convergence and high calculation accuracy.In this paper, a FDTD-based method is proposed for transient electrothermal analysisof global interconnects structure with high frequency. Electrothermal coupling effects areconsidered by iteratively solving telegraph equation, which describes the electricalbehaviors of interconnects, and heat conduction equation, which describes the thermal distribution of lines. The concept of thermal transmission line has been established.Numerical results from the method are compared with those from the classic simulationtools. It is shown that the proposed method has high accuracy and efficiency. Theelectrothermal effect has been considered between electrical and thermal properties.Interconnect power dissipation raises the interconnect temperature while the rise of thetemperature improves the power dissipation for the rise of line resistance. Therefore,neglecting electrothermal effects will underestimate interconnect temperature andpropagation delay.