Investigation on Reliability of Embedded Ultrathin Sensor Chip in Organic Substrate Under Drop Impact Loading by Stresses Monitor and FEM Simulation

Reliability of the embedded ultrathin device in the organic substrate packaging is one of the major concerns during its applications. In this paper, drop impact tests were conducted to the embedded ultrathin stress sensor chip in the organic substrate. Stresses were monitored with the embedded stress sensor chip based on silicon piezoresistive effects. Dynamic explicit finite element model with the input-G method was built up to investigate the stress and strain behaviors of the embedded chip and solder bump. The drop impact simulation model was validated by the experimental stresses monitoring result. It indicated that the discrepancy of the maximum normal stress σ₁₁ at the center of embedded stress sensor chip from experimental and numerical simulation results could be within 30%. Based on the validated model, the effects of material properties and structural parameters on the stress and strain responses were studied with the numerical simulation results. The maximum normal stress σ₁₁ at the embedded sensor chip and the equivalent plastic strain of the solder bump were selected as the indexes for the comparisons and optimizations. The experimental and numerical simulation efforts can provide design guidelines for the embedded ultrathin chip in the organic substrate packaging.