Failure analysis of complex 3D stacked-die IC packages using Microwave Induced Plasma afterglow decapsulation

Quality control and failure analysis of IC packages require physical access to the die during destructive analysis. Successful analysis depends on the critical preservation of the original state of the die, bond wire, bond pad, and original failure sites during the package decapping process. The currently used acid and conventional plasma decapping techniques have their intrinsic limitations in certain analysis cases, for example 3D stacked-die package with complex structures, HAST stressing that causes epoxy hardening, the use of epoxy refill materials and acid-resistant epoxy molding compounds, the use of Cu and PdCu bond wires, preservation of original die and bond wire surface features, preservation of original failure sites and contaminants, etc. Such difficult cases with conventional decapping techniques often suffers from low analysis accuracy and low confidence level during root cause failure analysis, and consequently poses major threat to the quality assurance of the IC products.