Authors: Priyanka Dobriyal, Lauren Cummings, Chet Lee Company: Intel Corporation Date Published: 9/17/2017
Abstract: As wearables and Internet of Things (IoT) devices gain consumer popularity, there is a growing trend in package miniaturization. A variety of thin and high-density technologies are gaining momentum in industry, including direct chip attach (DCA), the wafer-level package (WLP), and system-in package (SiP). Due to their small form factor and complex integration, these technologies pose a challenge for failure analysis (FA), particularly after board assembly. Conventional board-level FA techniques—such as dye-and-pull and cross-section—can destroy the true failure signature by inducing cracks or delamination. Even newer FA techniques—such as X-Ray computed tomography—can be time-consuming, and sometimes incapable of identifying subtle cracks or solder extrusions.
This paper addresses the FA challenges encountered for two separate SiP and WLP functional failures. Board-level FA and package-level FA techniques were leveraged for root cause findings, and process improvements were made to preserve the defect signature.