芯片的隐形杀手

Core Viewpoint - Noise has become a critical issue for semiconductor designers, affecting signal integrity and device performance as technology scales down to 7nm and below [3][4][5]. Noise Sources and Impact - Noise can be defined as any deviation from the ideal state that may affect expected functionality, with sources including temperature instability and flicker noise [2]. - Power noise can reach 5% to 10% of the nominal VDD if not managed properly, exacerbated by lower power voltages and higher current densities [3]. - The complexity of modern packaging and increased transistor density have diminished traditional design margins, making even minor fluctuations potentially detrimental [3][4]. Signal Integrity Challenges - Signal integrity issues have existed for over 30 years, but the integration of chip and system design has introduced new challenges for chip designers [4]. - Advanced chips consume significant power, leading to noise that overlays digital designs with analog characteristics, complicating power supply stability [5]. Advanced Packaging Issues - Advanced packaging technologies like 2.5D/3D integration introduce new challenges, including power integrity issues and electromagnetic coupling, which can degrade performance [7][8]. - The proximity of interconnects in advanced packaging increases crosstalk and noise across power networks, complicating noise management [5][7]. Verification and Testing Challenges - Noise is increasing the burden on verification processes, especially for circuits that intertwine analog and digital domains, requiring extensive testing under various conditions [10]. - The first-pass success rate for SoC chips using AMS technology is typically 10% to 15% lower than for pure digital chips due to insufficient coverage of extreme conditions [10]. Solutions and Strategies - Noise management can be approached through existing tools, focusing on RTL design choices and backend power network design [14]. - The integration of on-chip voltage regulators is being explored to mitigate noise, although this may increase costs and complexity [14]. - A holistic view of chip, package, and system as an integrated power distribution network can help in designing lower-noise chips [14].