Fully Polyimide-Based Hybrid-Integrated Thin Electronic Device With Bending-Induced Connection Stability Improvement of Seven Times

In this work, a fully polyimide-based hybrid integration method is for the first time proposed to not only enable bendability but also enhance computational functionality by packaging silicon-based IC die within flexible polyimide foil. Taking a commercial voltage regulator (VR) die as an example, the test results show that the entire thickness of the packaged chip is less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$500~\mu $ </tex-math></inline-formula>m, reduced by 71.6% compared to the corresponding commercial plastic-sealed chip. The percentage change of resistivity with curvature is reduced to 0.77% from about 5.2%, which of the bending-induced output stability is improved by seven times. Furthermore, the stability of the output voltage at the statics and dynamic condition can be kept constant to be 4.97 V. Especially, at the dynamic condition, the corresponding maximum fluctuation of the output voltage is just 6‰. This work provided some technology support to further break through integration application of large-scale complex flexible electronic system.