초록 열기/닫기 버튼
Purpose: The failure mechanism of electrical breakdown of organic substrate was identified. The median lives of various samples under biased Highly accelerated stress test (HAST) were determined from log-normal distributions. Methods: Failure analyses of electrical breakdown were conducted. Electrical test, optical microscopy, focus ion beam, electron microscopy, energy dispersive X-ray spectroscopy, and Fouriertransformed infrared were performed on electrical breakdown failure. Results: The median lives of the customer’s failed samples, the archived samples, and re-designed samples were measured to be 29.0 h, 59.5 h, and 270.8 h, respectively. The result promoted copper ion migration due to excessive water absorption of photosensitive solder resist, and the excessive water absorption results from the un-cured photosensitive solder resist. Conclusion: The electrical breakdown causes were uncured SR and consequent excess water absorption.
