VIA Reliability Evaluation of Embedded MLCC through Pressure Cooker Test

Abstract

A via reliability test of PCB board using embedded MLCC was evaluated by HALT and Pressure Cooker Test PCT. The reliability of HALT was evaluated at 125 ℃ , 4Vr, and 12Hr. The purpose of this test was to verify the stability of the MLCC by predicting the lifetime of the PCB. The PCBT conditions were measured at 85% humidity and 2 atm, and the reliability of the PCBs under severe conditions than HALT was evaluated. The basic characteristics of MLCC size are 0603 (600x300um), Capacitance 100nF, thickness 150µm. The initial electrical characteristics of the MLCC were measured at a rated voltage (10V) with a capacitance value of 98 ~ 103nF, a loss rate of 0.048%, and an insulation resistance of 1.08 x10 10 (Ω). The HALT test results showed that all the measured samples showed a value of 1x10 7 Ω or more, and passed for the HALT test. The PCBT test resulted in failure, and the first sample fell below the poor insulation resistance at the start of the PCBT test. In the case of the second sample, the insulation resistance dropped to less than the defective insulation resistance for more than 30 hours, and the third sample has an appropriate insulation resistance of 1.0x10 6 Ω even for more than 60 hours. It is confirmed that there is the greatest the possibility of failure in the part between the embedded chip and via that Cu plating is performed to form via by fill plating. Therefore, it is necessary to optimize the plating thickness and size conditions because the embedded MLCC has a high probability that defects mainly occur in VIA crack or delamination