Engine pressure sensor 2CP3-68 1946725 for Carter excavator

A method for preparing a pressure sensor, characterized by comprising the following steps:

S1, providing a wafer with a back surface and a front surface; Forming a piezoresistive strip and a heavily doped contact area onthe front surface of the wafer; Forming a pressure deep cavity by etching the back surface of the wafer;

S2, bonding a support sheet on the back of the wafer;

S3, manufacturing lead holes and metal wires on the front side of the wafer, and connecting piezoresistive strips to form a Wheatstone bridge;

S4, depositing and forming a passivation layer on the front surface of the wafer, and opening part of the passivation layer to form a metal pad area. 2. The manufacturing method of the pressure sensor according to claim 1, wherein S1 specifically comprises the following steps: S11: providing a wafer with a back surface and a front surface, and defining the thickness of a pressure sensitive film on the wafer; S12: ion implantation is used on the front surface of the wafer, piezoresistive strips are manufactured by a high-temperature diffusion process, and contact regions are heavily doped; S13: depositing and forming a protective layer on the front surface of the wafer; S14: etching and forming a pressure deep cavity on the back of the wafer to form a pressure sensitive film. 3. The manufacturing method of the pressure sensor according to claim 1, wherein the wafer is SOI.

In 1962, Tufte et al. manufactured a piezoresistive pressure sensor with diffused silicon piezoresistive strips and silicon film structure for the first time, and began the research on piezoresistive pressure sensor. In the late 1960s and early 1970s, the appearance of three technologies, namely, silicon anisotropic etching technology, ion implantation technology and anodic bonding technology, brought great changes to the pressure sensor, which played an important role in improving the performance of the pressure sensor. Since 1980s, with the further development of micromachining technology, such as anisotropic etching, lithography, diffusion doping, ion implantation, bonding and coating, the size of pressure sensor has been continuously reduced, the sensitivity has been improved, and the output is high and the performance is excellent. At the same time, the development and application of new micromachining technology make the film thickness of pressure sensor accurately controlled.