Reliability modelling state-of-the-art microelectronics

MEMS (Micro-Electro-Mechanical System) are miniature components, typically less than 100 microns in size, that can be mass-produced at low cost. These components are used in a range of markets including aerospace, medical, and transport technology, where high quality performance is essential. Therefore, effective reliability modelling is crucial to ensure that these products are suitable for consumer use.

Lancaster University researchers developed reliability modelling techniques for technology that was used by ST Microelectronics, a world leading electronics manufacturing company, to integrate its inertial MEMS into commercial products such as the iPhone and Nintendo Wii series. This collaboration generated over $3.5 billion in sales revenue between 2014 and 2020.

Over the past twenty years, a team of Lancaster University researchers, led by Professor Andrew Richardson, has been at the forefront of developing modelling techniques and optimisation technology to test MEMS for mechanical and thermal stress. Early collaboration with ST Microelectronics resulted in the first validated solutions for modelling component level faults in microstructures. This project used behavioural modelling techniques based on applications of Cosserat theory, developed by Professor Robin Tucker of Lancaster University’s Industrial Mathematics Group, to validate new methods for exploring mechanical fatigue in the material used in ST Microelectronics’ MEMS products.

The project later expanded to test to the reliability of silicon gyroscopes. Gyroscopes are small devices used to determine how quickly an object is rotating and are widely used in smartphones and other electronics devices. Further research by the Richardson team, alongside the French National Centre for Scientific Research, the University of Paris, and commercial partners, led to the development and application of a new ‘Bias Superposition’ method for testing the reliability of MEMS technology during normal use.

The work of the Richardson team had a significant economic impact by facilitating the use of ST Microelectronics’ inertial MEMS devices across several high-profile consumer products, including the iPhone 4 and 4S, Nintendo Wii and Wii U, and the Nintendo Switch. Between 2014 and 2020, the combined sales of these products exceeded 100 million units.

As well as this Lancaster University research solidifying ST Microelectronics’ position as a global leader in consumer MEMS technology, the University’s reliability modelling has also supported the longer-term commercialisation of new products, including accelerometers for vehicle safety applications in the automotive market.