System suppliers in the automotive market have an expectation that their IC suppliers provide products with low defective parts per million (DPPM) and have methodologies in place to drive towards 0ppm (Zero Parts Per Million). IC suppliers to the automotive market have supply chains and test methodologies in place to achieve such low DPPMs, but the systems suppliers will still require root cause analysis on every failure. The IC supplier is expected to demonstrate a containment, corrective action and continuous improvement in a very tight time frame. This additional demand of automotive customers poses a challenge to the quality of IC devices and the concept of cross departmental failure analysis. In this paper, we look at a complex Wi-Fi design with multiple IEEE specific radios, and how to address the few parts that escape the rigorous testing by IC supplier to improve the quality for the automotive IC.

A systemic analysis was chosen to evaluate a real case Bluetooth (BT) radio failure in the aspects of RF communication, digital design, firmware, application software, semiconductor device physics and processing, and failure analysis. This paper explores the range of testing, including customer application testing, required to confirm and localize a BT RF communication failure. It shows that the radio communication failure was not, as expected, caused by faulty radio hardware; it was rather linked to problematic encryption hardware at the assistance of the Synergy BT to mobile application. The paper also explores that the digital fault can only be detected by the timing sensitive transition fault scan patterns and how to obtain the physical failure location. Thus, the combination of ATPG and application testing provides a consistency between electrical diagnostics which yields a higher success rate at subsequent physical failure analysis of complex modern RF System on a Chip.