Flip Chip and Underfills

In this research area, materials and processes are being explored for flip chip assemblies deployed in extreme thermal cycling environments. The primary objective is to develop a fundamental understanding of the reliability of flip chip applications in automotive and other harsh environment applications. Project deliverables include: design and material guidelines for flip chip packages used in the automotive thermal cycling environment, material properties and adhesion characteristics of underfill encapsulants, flip chip thermal cycling reliability data, assembly and processing recommendations, and finite element and material models for application to future package designs.

Device Side Die Stress After CBGA Assembly and Heat Sink Clamping

Area-Leader

Dr. Jeffrey Suhling (Research Leader)

Objectives

  • Develop a Fundamental Understanding of the Influence of Package Design, Manufacturing, and Materials on the Reliability of Flip Chip Packaging in Harsh Environments
      -- Flip Chip on Laminate
      -- Flip Chip BGA packaging
      -- CSP (e.g., Redistributed Die, UltraCSP, etc.)
  • Measure and Predict the Reliability of Flip Chip Packaging
      -- Flip Chip on Laminate in Thermal Cycling and High Humidity Environments 
      -- High End Microprocessor Packaging 
  • Study Next Generation Materials
      -- Nano-Structured Underfills
      -- High reliability substrates (e.g., STABLCOR)
      -- Thermal Interface Materials
      -- Chip-Level Interconnects
  • Develop a Detailed Understanding of Underfill Behavior and Properties
      -- Material Behavior (Stress-Strain and Creep)
      -- Interfacial Adhesion and Failure Criteria
      -- Effects of Aging and Moisture Exposure

Project Titles

  • P14-201  Effects of Moisture on the Mechanical Behavior of Packaging Materials
  • P14-202  Effects of Moisture on the Reliability of Plastic Packaging
  • P15-201  Improved FEA Modeling of Area Array Assemblies

Representative Recent Publications

Flip Chip Packaging:

Nguyen, Q., Roberts, J.C., Suhling, J.C., Jaeger, R.C., Lall, P., A Study on Die Stresses in Flip Chip Package Subjected to Various Hygrothermal Exposures, Proceedings of the IEEE 2018 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2018), San Diego, CA, pp. 1339-1350, May 29-June 1, 2018.

Chen, C., Suhling, J.C., Lall, P., Improved Finite Element Modeling Strategies with Multipoint Constraints for BGA Packages Subjected to Thermal Cycling, Proceedings of the IEEE 2017 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2017), Orlando, FL, pp. 1456-1465, May 30-June 2, 2017.

Nguyen, Q., Roberts, J.C., Suhling, J.C., Jaeger, R.C., Lall, P., Characterization of Moisture Induced Die Stresses in Flip Chip Packaging, Proceedings of the IEEE 2016 Electronic Components and Technology Conference (ECTC2016), Las Vegas, NV, pp. 789-798, May 31-June 3, 2016.

Roberts, J., Bhat, C., Suhling, J.C., Jaeger, R.C., Lall, P., Reliability of a CBGA Microprocessor Package Incorporating a Decoupling Capacitator Array, Proceedings of the IEEE 2016 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2016), Las Vegas, NV, pp. 278-284, May 31-June 3, 2016.


Underfills:

Lall, P., Dornala, K., Deep, J., Lowe, R., Measurement and Prediction of Interface Crack Growth at the PCB-Epoxy Interface Under High-G Mechanical Shock, Proceedings of the IEEE 2018 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2018), San Diego, CA, pp. 1097-1105, May 29-June 1, 2018.

Lall, P., Dornala, K., Deep, J., Lowe, R., Effectiveness of Potting Methods and Underfills on the Enhancement of Survivability of Fine Pitch Electronics at 25,000g Shock Loads, Proceedings of the IEEE 2017 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2017), Orlando, FL, pp. 1262-1274, May 30-June 2, 2017.

Chowdhury, P.R., Suhling, J.C., Lall, P., Experimental Characterization of Underfill Materials Exposed to Different Moisture Condition, Proceedings of the IEEE 2017 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2017), Orlando, FL, pp. 1-12, May 30-June 2, 2017.

Lall, P., Dornala, K., Lowe, R., Foley, J., Survivability Assessment of Electronics Subjected to Mechanical Shocks up to 25,000g, Proceedings of the IEEE 2016 Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm2016), Las Vegas, NV, pp. 507-518, May 31-June 3, 2016.

Lall, P., Dornala, K., Suhling, J., Lowe, R., Foley, J., Life Prediction and RUL Assessment of Fine Pitch Solder Joint Fuze Electronics Under Mechanical Shock Loads Up to 50,000g, Proceedings of the IEEE 2016 Electronic Components and Technology Conference (ECTC2016), Las Vegas, NV, pp. 232-243, May 31-June 3, 2016.



Publications

Reviews