The differences between diffusion silicon pressure sensors and ceramic chip pressure sensors

Ceramic chip sensors and diffused silicon sensors are two common types of pressure sensors, each with unique characteristics suited for different applications. Below are the main differences and application distinctions between the two:

1. Material and Structure

- Diffused Silicon Sensors:  

  Diffused silicon sensors utilize single-crystal silicon material, employing micro-machining technology to form a sensitive bridge on the silicon wafer. Their internal structure includes a silicon diaphragm and piezoresistive bridge, converting pressure into an electrical signal through the strain effect on the silicon wafer surface.

- Ceramic Chip Sensors:  

  Ceramic chip sensors are based on ceramic materials (typically alumina ceramics) and use thick film technology to form an electrical bridge on the ceramic substrate. Ceramic materials have high elasticity, high strength, and excellent corrosion resistance, which means they do not require an additional isolation diaphragm and can be directly exposed to the medium.

 2. Environmental Resistance

- Diffused Silicon Sensors:  

  These sensors are sensitive to humidity, corrosive gases, and certain chemical media, thus requiring a protective isolation diaphragm on the sensitive element. They are suitable for general industrial environments but may require extra protective measures in highly corrosive or polluted environments.

- Ceramic Chip Sensors:  

  Due to the ceramic material's inherent corrosion resistance and anti-aging properties, ceramic chip sensors are more suitable for harsh environments, particularly corrosive media, humid conditions, and high temperatures. They do not require special protection, have a long lifespan, and offer high reliability.

 3. Pressure Range and Accuracy

- Diffused Silicon Sensors:  

  These sensors provide high accuracy and sensitivity, typically used for low to medium-high pressure ranges (from several hundred pascals to hundreds of megapascals). They are ideal for applications requiring precise measurements of gases and liquids, such as pressure control.

- Ceramic Chip Sensors:  

  Usually used for medium to low-pressure ranges (from several hundred pascals to tens of megapascals), they can also be used for higher pressure situations, though their accuracy is generally slightly lower than that of diffused silicon sensors. Due to their material properties, ceramic sensors are mainly used in applications that do not require extreme precision but demand strong environmental adaptability.

4. Temperature Characteristics

- Diffused Silicon Sensors:  

  These sensors are sensitive to temperature changes and require temperature compensation. In environments with significant temperature variations, diffused silicon sensors may experience temperature drift, necessitating additional temperature compensation circuits to maintain stable measurement accuracy.

- Ceramic Chip Sensors:  

  They have good temperature stability and minimal temperature drift, performing stably in environments with large temperature fluctuations. They are suitable for high-temperature environments or applications with significant temperature variations.

5. Application Scenarios

- Diffused Silicon Sensors:  

  Widely used in industrial process control, aerospace, automotive manufacturing, medical devices, and meteorological instruments. They are especially suited for high-precision and fast-response applications, such as pressure monitoring, gas flow control, and liquid level measurement.

- Ceramic Chip Sensors:  

  Mainly used in water treatment, food and beverage, chemical, petroleum, environmental protection equipment, pharmaceuticals, and HVAC (heating, ventilation, and air conditioning) systems. They are suitable for applications requiring corrosion resistance, high-temperature stability, and high mechanical strength, such as liquid level control and pressure measurement of corrosive media.

 Summary

Ceramic chip sensors and diffused silicon sensors each have their advantages and limitations. Diffused silicon sensors are ideal for high-precision, fast-response scenarios but have higher environmental requirements; ceramic chip sensors, with their corrosion resistance, high-temperature endurance, and high mechanical strength, are more suitable for use in harsh environments. The choice between these sensors depends on specific application requirements, including pressure range, accuracy needs, environmental conditions, and cost factors.

For 10 bar pressure monitoring, both  diffused silicon chips and  ceramic chips  are suitable, but the choice depends on specific application requirements and environmental conditions:

- Diffused Silicon Chip:  

  More suitable for applications requiring high precision and sensitivity. If your application requires very accurate pressure measurement, such as in industrial process control or precise monitoring of gas and liquid pressures, a diffused silicon chip might be the better choice. Diffused silicon sensors can provide very stable readings after temperature compensation, making them suitable for relatively mild environments without corrosive media.

- Ceramic Chip:  

  More suitable for use in harsh environments, especially where there are corrosive media, high humidity, or temperature fluctuations. If your application environment includes corrosive gases or liquids, or requires a sensor with higher mechanical strength and corrosion resistance, then a ceramic chip might be more appropriate. Ceramic chips can provide sufficient accuracy at 10 bar pressure and do not require special protective measures.

 Conclusion

If the application requires high precision and temperature compensation, and the environmental conditions are relatively mild, choosing a **diffused silicon chip** would be more appropriate. If the application environment is harsh, with corrosive media or requires higher mechanical durability, then a **ceramic chip** would be the better choice.