INSPECT- Integrated 2D Magneto resistive Probe - SiPS - INESC-ID

INSPECT- Integrated 2D Magneto resistive Probe for Non Destructive Testing
with Eddy Currents
“INSPECT - Integrated Nano Sensor Probes and Electronics for Eddy Currents Testing
PI: Moisés Simões Piedade
Project FCT: PTDC/EEI-PRO/3219/2012
Authors: Tiago Costa, Moisés Piedade, Luis Rosado, Filipe Cardoso, and Paulo Freitas
INESC-ID and INESC-MN , September 2015
•This advanced probe is based on a specific CMOS integrated circuit specially designed to allow the
implantation of a bi dimensional array of magneto resistive sensors over it, using microelectronics thin
film technology.
CMOS circuit was designed by INESC-ID and the post processing of the magnetic sensors array was
performed and fabricated by INESC-MN. Magneto resistive sensors fabricated are high performance spin
valves configured as a 2 D array of 256 sensors deposited over CMOS circuit. The integrated circuit
includes ultra-low noise circuits leading to:
• SV sensor current biasing.
• 2D array addressing (one CMOS diode per cell).
• Amplification (maximum gain of 80 V/V)
• Ultra low Noise measured:
• < 16 nV/sqrt(Hz) @ 100 Hz
• 11 nV/sqrt(Hz) f >1 kHz
• Signal Bandwidth: 125 kHz.
Chip micro photography
Probe Prototype
NDT based on eddy
The probe prototype was tested in a special mock-up for defect characterization, obtaining the
following results:
Test mock-up
Measured results