Especially for fast flow measurements and wire bonding assembly, the Flow Sensor MFS 02 was developed. Due to a membrane system the thermal mass is reduced to the minimum. Very fast response time and low power consumption are resulting from this little thermal mass.
The membrane is just a few microns thick and is carried by a glass substrate. Therefore the system is robust and the device can be handled easily.
Advantages of MFS 02 Flow Sensor
The advantages of MFS 02 Flow Sensor include:
- Fast response time
- Small mass flow rates
- Detection of flow direction
- Low power consumption
- Small thermal mass
- Robust design
- Best price-performance ratio
Applications of MFS 02 Flow Sensor
- Medical devices
- Home spirometers
- Differential pressure sensors
- Mikrofluidic (gas)
MEMS-Manufacturing Process –F O T U R A N
Final sensor element
MEMS-Manufacturing Process –Sensor Structures
- Photo structured glass substrate with membrane -polymere dot
- Spin coating prozess
- Sputtering thin film platinum
- Photolithographic mask process
- Ion based etching process
- RTD-structure passivation
Sensor Application –Chip Layouts and Circuits
- Different resistor arrangements and values depending on flow application
- Customized sensors possible because of inexpensive mask processes
Simple resistive structure for using in CTA -mode
Using as full bridge with Constant voltage or current supply Flow direction sensitive
Using as full bridge in a CTA; Flow direction sensitive
Sensor Application –Thermal Sensor Properties
Simple full bridge calorimeter mode Sensor supply 3mA and about 2,5 volts Flow rate 0,00 mlN/min
Simple full bridge calorimeter mode Sensor supply 3mA and about 2,5 volts Flow rate 200 mlN/min
Full bridge calorimeter mode and CTA biasing Sensor supply 4mA and about 3,5 volts Flow rate 600 mlN/min
Sensor Application –Measuring Properties
- Unamplified nominal sensitivity 3mV/ mlNmin-1 In zero cross point
- Physical flow range enlargement by full bridge mode with CTA biasing
- No cool down effect of heater with CTA biasing.
- Heating power 10mW to 50mW
- Stable zero cross point; independent on any drift effects like contamination.
High flow CTA mode-range
Sensor Application –Assembly Possibilities
- Easy to use and robust sensor construction
- PCB integration by mounting in a cavity or hole
- Connecting by wire bonding or soldering
- Backsite mounting of flow channel
- Sensor mounted in a separate flow channel
- wire bonded flow sensor for pcb connection
- Pick & place assembling of sensor possible
- Plug and play module by USB interface
Example with the wire bonding sensor type MFS02 together with an ASIC on a pcb.
This information has been sourced, reviewed and adapted from materials provided by Innovative Sensor Technology, USA Division.
For more information on this source, please visit Innovative Sensor Technology, USA Division.