Non-contact wafer-level TSV connectivity test methodology using magnetic coupling

Motivated by the abrupt miniaturization of mobile devices and demand for 3D-IC, Through Silicon Via (TSV) has been highlighted as the key technology for compactly integrating multiple dies of various functions as a whole system. With dramatic growth in the number of TSVs in TSV-based 3D-IC, a need for accurate detection of TSV disconnection defects arose, to compensate for the instability in the TSV fabrication processes. In this paper, we experimentally verify the proposed contactless wafer-level TSV connectivity testing structure using magnetic coupling that can detect TSV disconnection defects on wafer-level. The proposed structure can detect the TSV disconnection by observing the change in the capacitance between adjacent TSVs, using only passive components such as metal pads and lines, without additional power consumption for the testing. While the proposed structure aims to test TSVs on wafer-level, since the fabrication of the test vehicle is difficult, a similar structure is designed and fabricated on PCB-level for experimental verification. Through time- and frequency-domain measurement results, such as transfer impedance and voltage waveforms, we verified that the proposed structure can successfully detect disconnection defects without physical contact, while overcoming the limitations of the conventional direct probing methods.