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Reliability Analysis of Flip-Chip Packaging GaN Chip with Nano-Silver Solder BUMP
Lei Yan1, Peisheng Liu1, Pengpeng Xu1
1Jiangsu Key Laboratory of ASIC Design, School of Information Science and Technology, Nantong University, Nantong 226019, China.
Micromachines
|June 28, 2023
Summary
Flip-chip packing (FCP) for gallium nitride (GaN) power devices with underfill significantly reduces thermal stress. Nano-silver bumps with aluminum under bump metallurgy (UBM) offer the most reliable thermal management solution for GaN chips.
Area of Science:
- Materials Science
- Electrical Engineering
- Thermal Management
Background:
- Gallium nitride (GaN) power devices offer high performance but suffer from low thermal conductivity, leading to overheating issues.
- Effective thermal management is crucial for the reliability and performance of GaN power devices.
Purpose of the Study:
- To develop a reliable thermal management model for flip-chip packed (FCP) GaN chips.
- To investigate the impact of different solder bumps and under bump metallurgy (UBM) on thermal stress and performance.
Main Methods:
- A flip-chip packing (FCP) model for GaN chips was established using Ag sinter paste structure.
- Simulations considered various solder bumps and under bump metallurgy (UBM) materials.
- Temperature shock experiments were performed with different UBM materials.
Main Results:
- FCP GaN chips with underfill demonstrated reduced package size and significantly lower thermal stress (79 MPa, 38.77% of Ag sinter paste structure).
- Nano-silver emerged as the most suitable bump material for FCP GaN chips.
- Aluminum (Al) was identified as a more reliable UBM material for temperature shock resistance.
Conclusions:
- Flip-chip packing with underfill is a promising thermal management strategy for GaN power devices.
- Nano-silver bumps and aluminum UBM provide a robust and reliable solution for enhancing GaN device performance and longevity.
