# Piezoresistivity in microelectronics and its formalization using linear algebra

Leuven - Master projects/internships
|
Meer dan twee weken geleden

Development the methodology for analyzing the electrical response of piezoresistive sensors integrated in IC packages for accurate evaluation of mechanical stresses through solutions of linear equations and sensitivity analysis

Experimental evaluation of Chip-Package Interaction (CPI) in microelectronics devices is a valuable technique which allows assessment of 3D integration and packaging technologies in terms of their mechanical stability and reliability. It includes electrical measurements of integrated piezoresistive stress sensors and data analysis. The later employs linear algebra to derive components of mechanical stress from the measured electrical data and the calibrated piezoresistivity coefficients. As in any experimental method, electrical measurements of the integrated piezoresistive sensors are not free of noise and uncertainties and include both random and systematic errors which require additional sensitivity analysis and finding the best algorithm for the data analysis and the interpretation of the experimental results.

The work of the student will include:

1. Analysis and systematization of large amounts of experimental data,
2. Development of formal mathematical algorithms for conversion of experimental electrical data into the components of mechanical stress,
3. Assessment of systematic and random noise based on the additional experiments and data analysis,
4. Sensitivity analysis of the developed (in item 2) algorithms based on the data obtained in item 3,
5.  Development and implementation of a user-friendly GUI interface based on the algorithms developed in items 1-4.

This is very challenging and complex project and thus successful completion of two tasks from above can be considered as success criteria for the master thesis.

The student should satisfy the following criteria:

1. Master in mathematics with strong background in linear algebra and statistics,
2. Programing skills,
3. Basic knowledge of theory of piezoresistivity, material science (stress-strain relationship) and knowledge of electrical measurements and instrumentation are not strictly required but preferred.

​Figure. Simulated distribution of vertical stress in Si die above flip-chip pillar (left) and (right) measured response of piezoresistive stress sensor above pillars located at the corner and center of the die.

Type of project: Thesis

Duration: 6 months

Required degree: Master of Engineering Technology, Master of Science, Master of Engineering Science

Required background: Computer Science, Electrotechnics/Electrical Engineering, Nanoscience & Nanotechnology, Physics