考虑寄生参数影响的芯片RC-HBM静电测试模型

RC-HBM electrostatic test model of chip considering the influence of parasitic parameters

采用常规的人体模型(Human Body Model,HBM)进行静电释放(Electro-Static Discharge,ESD)测试时往往容易受到寄生参数的影响,使得电源芯片抗静电能力测量值与实际抗静电能力存在偏差,导致劣质产品通过HBM ESD测试,影响电源芯片产品良品率的提升。为此,提出了一种RC-HBM模型,通过引入RC并联支路,校正因寄生参数引起的静电放电电流的偏差,满足电源芯片静电可靠性测试的要求。首先阐述了静电对电源芯片的损坏机理。其次,分析了寄生参数对ESD电流的影响,阐述了常规HBM ESD测试的局限性。并提出了一种新型的RC-HBM模型,给出了RC并联支路参数的设计依据。最后,通过批量实验验证了所提RC-HBM模型的准确性和合理性。

When the conventional human body model(HBM)is used for electro-static discharge(ESD)testing,the measured value of the power chip’s antistatic ability deviates from the actual antistatic ability because of a parasitic effect,resulting in inferior products passing the HBM ESD test.This affects the improvement of the yield rate of power chip products.To this end,an improved HBM model is proposed,one which corrects the deviation of the electrostatic discharge current caused by parasitic parameters by introducing an RC parallel branch to meet the requirements of the electrostatic reliability test of the power chip.First,the mechanism of how static electricity causes damage to the power chip is described.Secondly,the influence of parasitic parameters on the ESD current is analyzed,and the limitations of the conventional HBM ESD test are elaborated.Then a new RC-HBM model is proposed,and the design basis of the RC parallel branch parameters is presented.Finally,batch experiments verify the accuracy and rationality of the HBM model proposed.