Diploma thesis for Erik Utne Poppe
Area of work: Microelectronics
Title
Calibration and use of a silicon test chip to investigate reliability and thermal performance of flip-chip assembled multi-chip modules.
Description of the work
The reliability of flip-chip bonded circuits is limited by thermal expansion mismatch between chip and substrate. The strain which is introduced in the solder contacts will cause fatigue under thermal or power cycling, which may eventually lead to bond failure.
The aim of this work is to investigate the fatigue process by use of a silicon test chip containing structures for measuring stress, chip temperature and electrical continuity.
The work includes:
- Literature survey of methods for relating thermal induced stress and bond lifetime.
- Development of calibration procedures for on-chip sensors
- Performance of measurements of stress and temperature in the chip under thermal and power cycling.
- Experimental determination of bond lifetime
- Develop/assess mathematical model for predicting lifetime under power and temperature cycling based on the above meas. and methods found in the literature survey
The work was carried out at SINTEF Instrumentation, Microelectronics section.