Pressure-sensitive element of piezoresistive pressure sensor is a piezoresistive element, Pressure Sensor which is based on the piezoresistive effect. The so-called piezoresistive element is actually refers to the semiconductor material on the substrate with the integrated circuit technology made of the diffusion resistance, when it is subjected to external forces, its resistance due to changes in the resistivity changes. Pressure Sensor The diffusion resistance should be attached to the elastic element when it is working normally, and the single crystal silicon diaphragm is commonly used.
The Piezoresistive chip uses a fixed silicon cup structure around the perimeter and is encapsulated inside the enclosure. Pressure Sensor On a circular mono-crystalline silicon diaphragm, four diffuser resistors are arranged, two slices are in compressive stress area, and the other two are in tensile stress area, they form a full bridge measuring circuit. The silicon diaphragm is fixed with a round silicone cup, with two pressure cavities on either side, a high-pressure cavity connected to the measured pressure, the other being a low-pressure chamber, a reference pressure, and usually a pressure atmosphere. Pressure Sensor When there is pressure difference, the diaphragm produces deformation, so that the resistance of the two pairs of changes, the bridge is out of balance, the output voltage reflects the diaphragm on both sides of the pressure differential size.
A single wafer chip can only be used as a part of a detection unit can not independently complete the signal conversion, so there must be a specific package to have the ability to detect pressure. The wafer chip in Fig. 2 is sealed with electrostatic Pyrex glass ring. Pressure Sensor Pyrex Glass Ring as a silicon chip mechanical fixed support elastic sensitive elements and the silicon chip and packaging insulation, Pyrex glass ring of the hole just become the sensor reference pressure cavity body and electrode lead chamber. Its structure is shown in Figure 4. The sensitive core of FIG. 4 is sealed on the metal thread base to form the inlet of the pressing cavity, Pressure Sensor and becomes an installable pressure measurement front end, as shown in Fig. 5. This packaging technology can carry at least 15MPa of pressure, if the special treatment can carry 100MPa pressure.
Pressure sensor is one of the most commonly used sensors, it is widely used in a variety of industrial automation environment, involving water and electricity, railway traffic, intelligent building, production control, aerospace, military, petrochemical, oil wells, electric power, ships, Pressure Sensor machine tools, pipelines, etc.
The pressure control device made by pressure sensor is commonly called electronic weighing system, and the electronic weighing system is becoming more and more important as an online control tool for material flow in various industrial processes. The electronic weighing system can not only combine to optimize production in the manufacturing process, improve the quality of products, Pressure Sensor but also collect data from the material flow in the process of production and transmit it to the data Processing Center for online Inventory Control and financial settlement.
In the process automation control of weighing, it is required that the pressure sensor not only can perceive the gravity signal,Pressure Sensor but also its performance must be reliable, the dynamic response is better and the anti-interference performance is better. The signal provided by the pressure sensor can be directly displayed, recorded, printed, stored or used for feedback control.