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High Throughput Single-cell and Multiple-cell Micro-encapsulation
Published on: June 15, 2012
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Capillary Underfill Flow Simulation as a Design Tool for Flow-Optimized Encapsulation in Heterogenous Integration.
Lisa Christin Stencel1, Jörg Strogies1, Bernd Müller1
1Siemens AG, T ICE ELM-DE, 13629 Berlin, Germany.
Micromachines
|October 28, 2023
Summary
This study introduces a precise capillary two-phase flow simulation for defect-free underfilling in power electronics. Predictive engineering optimizes package designs for enhanced reliability and manufacturing yields.
Area of Science:
- Materials Science
- Computational Fluid Dynamics
- Power Electronics Packaging
Background:
- Capillary underfilling is crucial for advanced power electronics integration.
- Achieving defect-free encapsulation is critical for device reliability.
Purpose of the Study:
- To develop and validate a precise capillary two-phase flow simulation for underfilling.
- To investigate factors influencing flow accuracy and explore flow manipulation strategies.
Main Methods:
- Volume of Fluid (VOF) method for two-phase flow simulation, optimized with HRIC blending, artificial viscosity, and implicit Multi-Stepping.
- Digital mapping integrating physical experiments and virtual simulations.
- Exploration of flow manipulation techniques: local speed adjustment, gap segmentation, and arcuate shapes.
Main Results:
- VOF method demonstrated superior accuracy and efficiency over the Level-Set method.
- Transient flow predictions showed excellent agreement with experimental data (1.48-3.34% deviation).
- Non-Newtonian viscosity and time-dependent contact angles significantly impact prediction accuracy.
Conclusions:
- Predictive engineering using validated flow simulations can optimize underfilling processes.
- Flow manipulation strategies effectively control interface confluence and improve encapsulation.
- Optimized designs enhance power electronics reliability and manufacturing yields.

