BiSn-Based Low-Temperature Soldering Process and Reliability, Phase 3b (Thermal Cycling)

In 2015, INEMI initiated the BiSn-Based Low-Temperature Soldering Process and Reliability Project (LTSPR) to assess the feasibility of using low-temperature solders in the SnBi system to address various technological, economic and ecological drivers for assembly of consumer computer electronic board products.

The overall project objective was to assess the surface mount processability and reliability of the solder joints formed when enhanced BiSn-based solder pastes are used for assembling electronic components on printed circuit boards. To date, the project has:

Phase 1 — developed assembly processes on selected low temperature solder pastes

Phase 2 — conducted mechanical shock reliability evaluation

Phase 3a — assessed the temperature cycling fatigue reliability of BGA solder joints of two different sizes with homogeneous and heterogeneous microstructures, under three distinct temperature cycling protocols. Results from these studies were published.

 

Focus of Phase 3b

Phase 3b is planned as addendum to the original LTSPR project SOW (V1.3, December 2015). In this phase, the project team plans to:

• Assess the temperature cycling fatigue reliability of near eutectic SnBi solder joints with the upper dwell temperature being > 0.95 homologous temperature for the SnBi alloy and compare with Phase 3a results from three other temperature cycling protocols with upper dwell temperatures < 0.95 homologous temperature

• Assess the temperature cycling fatigue reliability of LTS reverse hybrid solder joint for the standard 0-100ºC protocol and compare it with full SAC305 and full LTS SnBi solder joints.
  
  

Presentations

Presentation: Call-for-Participation Webinar (April 22 & 18, 2025)