Characterization of Silicon Piezoresistive Stress Sensors for Thermal-Mechanical Test Chip

Piezoresistive stress sensors can effectively measure die stress mapping for reliability investigations. Applications like solder bump reliability monitoring have used online daisy chain resistance measurements to predict bump failure/fatigue. However, early stages of crack initiation in this method cannot be detected due to high interface pressure. 

We have designed a thermal-mechanical test chip including serpentine and VDP piezoresistive stress sensors. This chip provides both thermal and mechanical reliability experiments simultaneously in different assembly technologies.

Assignment

The student will perform the assignment at ECTM:

• Duration: ~9 months.
• Location: Measurement lab and EKL facilities*.
• *Collaboration with NXP/IMEC might be required for mechanical test set-up preparation (4PB machine)

The expected activities to be carried out by the student are:

• Preparing the electrical setup for mechanical tests.
• Extraction of piezoresistive coefficients of the stress sensors at different temperatures/doping levels.

Requirements

You are an ambitious student looking for a challenging thesis project on a sensor characterization and optimization problem. You have a physics, or microelectronics background and an interest in hands-on experiences and electronic measurement setups. Experience with running scripts in LabVIEW is highly recommended. Good communication skills in English and a pro-active attitude are expected.

Contact

Last modified: 2022-04-11