3D MEMS Accelerometers for Building Applications

Mikaël Colin – MEMScAP S.A.

1st MEMSCON Event – Bucharest

October 7th, 2010

1st MEMSCON Event07/10/10, Bucharest Company

Acceleration RF ID tag

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

Accelerometer end-user specifications

Parameter Value Unit

Acceleration 0.01-2 g

Frequency 0.1-10 Hz

Duration 15 s

Size constraint - mm3

Operating temperature -20 to +50 °C

Operating Humidity 0 to 100 %RH

Vibrations (15g) 1000 Hz

Shocks 2000 g

Battery lifetime 2 years

3D MEMS accelerometer

MEMS = Micro ElectroMechanical System

Accelerometers transduction mechanisms

Vibration Beam Accelerometer (VBA) Resonance frequency is dependent on the applied force Driven oscillator at resonance frequency (closed loop) High end applications

Company1st MEMSCON Event07/10/10, Bucharest

Spring Mass System Acceleration force causes a proof

mass displacement Displacement measurement system Direct or indirect measurement Indirect measurement methods:

Piezoelectric effect Piezoresistive effect Capacitive sensing

Transduction principles

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

Piezoelectric effect Piezoresistive effect

Capacitive sensing

MEMS Technologies

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

Bulk micromachining

Surface micromachining

Hybrid integration

Concept of 3D accelerometer

Mounting of 3 1D accelerometers

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

3-axis sensitive mechanical structure

3 independent structures on the same die

Selected concept

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

3 independent capacitive micromachined sensors on a single die

~ 4mm

~ 11mmOut of the wafer plane sensitivity In plane sensitivity

Fabrication

Wafer level packaging concept

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

ASIC+MEMS Assembly

Hybrid integration in a ceramic carrier

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest

MEMSASIC Read-out

Thank you for your attention

MEMScAP, France1st MEMSCON Event - 07 October 10, Bucharest