Product OverviewPressure Sensor Dies - Pressure Measurements Methods

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The high precision of piezoresistive sensors and their ability to measure absolute, gauge and differential pressure allow their versatile use in a wide range of applications.

For industrial equipment and machineries the information provided by the pressure sensors can be used to operate hydraulic or pneumatic equipment in the most effective way but furthermore connect to the new Industry 4.0 standards.

The increasing requirements in automotive for fuel efficiency and reduction of harmful emission demand for long-term stable and highly accurate sensors. Besides the media resistance, some of the application require the pressure sensors to be freeze resistant but most important the sensors need to provide a reliable signal over lifetime.

All applications place increasingly demanding requirements on the distinctive characteristics of the pressure dies and call for specific design features already on the die level. The TDK pressure sensors portfolio has been developed with a strong focus on increased sensitivity and high performance with a smaller die size. In addition, particular attention is paid to specific features for media resistance and easy process ability.

Piezoresistive pressure sensing methods

Piezoresistive pressure sensing methods
Absolute
 
Gauge   Differential
 

Piezoresistive pressure measurement

Piezoresistive pressure measurement

Absolute pressure measurement – front side

The reference vacuum is created by bonding the glass under vacuum to the silicon. The medium to be measured comes into contact with the active electronic components on the front side of the pressure sensor die.

Table 1 : Absolute pressure measurement – front side
Type C32
C43
C33
C39
Dimension: 1.65 x 1.65 x 1.1 mm³ 1.65 x 1.65 x 1.1 mm³ 1.0 x 1.0 x 0.4 mm³ 0.65 x 0.65 x 0.24 mm³
Media: Dry non-aggressive gases Dry non-aggressive gases Dry non-aggressive gases Dry non-aggressive gases
Pressure range: 0 … 1.0 to 0 … 40 bar 0 … 10 to 0 …40 bar 0 … 1.2 to 0 … 10 bar 0 … 1.2 bar
Temperature range: -40 °C to +135 °C -40 °C to +135 °C -40 °C to +135 °C -40 °C to +135 °C
Features:
  • All around bond pad layout
  • Outstanding long-term stability
  • High signal stability

→High temperature coefficient resistance on request
  • Optimized for high burst pressure
  • Outstanding long-term stability
  • High signal stability

→High temperature coefficient resistance on request
  • Outstanding long-term stability
  • High signal stability
  • Miniaturized design
  • Narrow tolerance of sensitivity
  • High signal stability
  • Miniaturized design
Cross-section:

Absolute pressure measurement – backside

For non-aggressive gases and fluids the reference chamber is created on the front side by an additional glass cap.
The media is being applied to the backside entry.

Table 2 : Absolute pressure measurement – backside
Type C32
C38
C44
Dimension: 1.65 x 1.65 x 1.5 mm³ 1.65 x 1.65 x 1.5 mm³ 1.65 x 1.65 x 1.5 mm³
Media: Non-aggressive gases and fluids Non-aggressive gases and fluids Non-aggressive gases and fluids
Pressure range: 0 … 0.4 to 0 … 25 bar 0 … 10 to 0 … 40 bar 0 … 10 to 0 … 40 bar
Temperature range: -40 °C to +135 °C -40 °C to +135 °C -40 °C to +135 °C
Features:
  • For wet media applications
  • Outstanding long-term stability
  • High signal stability
  • For wet media applications
  • High burst pressure
  • Single side bond pad layout for direct die to die wire bonding
  • Outstanding long-term stability
  • For wet media applications
  • Optimized for high burst pressure
  • Outstanding long-term stability
  • High signal stability
Cross-section:
Specific features: →Solderable
 →Solderable
 →Solderable

Gauge and differential pressure measurement

Gauge or differential pressure measurement is measuring the difference between the front and the backside. A pressure difference caused by a higher front side pressure leads to a positive change of the output signal. A higher backside pressure leads to a negative change of the output signal.

Table 3 : Gauge and differential pressure measurement
Type C35
C32
C38
C43
Dimension: 2.05 x 2.05 x 1.2 mm³ 1.65 x 1.65 x 1.1 mm³ 1.65 x 1.65 x 1.1 mm³ 1.65 x 1.65 x 1.1 mm³
Media: Non-aggressive gases and fluids Non-aggressive gases and fluids Non-aggressive gases and fluids Non-aggressive gases and fluids
Pressure range: 0 … 0.1 bar 0 … 0.4 to 0 … 25 bar 0 … 10 to 0 … 40 bar 0 … 10 to 0 … 40 bar
Temperature range: -40 °C to +150 °C -40 °C to +135 °C -40 °C to +135 °C -40 °C to +135 °C
Features:
  • Various wire bond options (surrounded wire bonding and direct die to die)
  • Narrow tolerance of sensitivity

→High temperature coefficient resistance on request
  • All around bond pad layout
  • Outstanding long-term stability
  • High signal stability

→High temperature coefficient resistance on request
  • Single side bond pad layout for direct die to die wire bonding
  • Outstanding long-term stability
  • High signal stability
  • Optimized for high burst pressure
  • Outstanding long-term stability
  • High signal stability

→High temperature coefficient resistance on request
Cross-section:
Specific features:  

→Gold bond pads for high temperature and corrosion stability

    

Applications of Pressure Sensor Dies

Table4 : Applications of Pressure Sensor Dies
  C32 C33 C35 C38 C39 C43 C44
 
Front side absolute
Backside absolute
Gauge/ differential
Front side absolute
Gauge/ differential
Backside absolute
Gauge/ differential
Front side absolute
Front side absolute
Gauge/ differential
Backside absolute
Automotive × × × × × × × × × × ×
Industrial × × × × × × × × × × ×
Medical × × × × × × × × × × ×
Consumer × × × ×       ×      

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