Wafer-Level Characterization of Probecards using NAC Probing

This paper presents Needle Auto Calibration (NAC) probing technique to measure the electrical characteristics of Probecard for wafer-level test. Probecard needle alignment and probing tasks, which are generally known to be hard and time-consuming, can be done easily through automatic Probecard aligning function of NAC. The inaccuracy problem during measurements by NAC probing due to difficulties of calibration is compensated by adapter characterization and de-embedding techniques. According to our experimental results, the inaccuracies of group delay, insertion loss and phase characteristic are decreased from 30.4% to 2.71%, from 1.75% to 0.53%, and from 35.2% to 1.32%, respectively.