CN-121994409-A - Pressure calibration method based on conventional production calibration equipment and applicable to full-temperature section

Abstract

The invention discloses a pressure calibration method based on conventional production calibration equipment and capable of being used for a full-temperature section, which adopts a double-stage strategy of laboratory depth modeling and production rapid calibration, effectively solves the technical problems that the existing full-temperature section pressure calibration is seriously dependent on expensive high-low temperature equipment, and is high in production cost and low in efficiency, and particularly, the method only needs to collect a small amount of samples at a laboratory stage to construct a correction coefficient model, and conventional production calibration equipment only with zero temperature testing capability can be utilized at a large-scale production stage, and offset parameters and sensitivity parameters are secondarily corrected by collecting the zero temperature section calibration point data and combining correction coefficients, so that on the premise that a production line is not required to be configured with a low-temperature environment, equipment investment and time cost are greatly reduced, production is remarkably improved, and a high-precision pressure calibration effect of a sensor can be obtained at the full-temperature section (including a zero low-temperature zone).

Inventors

• ZHANG HUATONG
• WU YIKANG

Assignees

• 深圳市华普微电子股份有限公司

Dates

Publication Date

20260508

Application Date

20260409

Claims (7)

1. 1. A pressure calibration method based on conventional production calibration equipment for a full temperature section, comprising the steps of: according to the calibration requirement, determining the temperature and pressure values of the calibration points of the zero temperature section to be acquired; in the laboratory stage, acquiring zero pressure and maximum pressure data of two sub-zero temperature points of a plurality of MEMS sensitive elements in the same batch in addition to the zero temperature segment calibration point data; Calculating calibration coefficients of all pieces of MEMS sensitive elements according to the above-zero temperature segment calibration point data, and calculating offset parameters and sensitivity parameters of the two below-zero temperature points by using the calibration coefficients; According to the data acquired by the two temperature points below zero, calculating the real offset parameter and the sensitivity parameter of each piece of MEMS sensitive element, modeling the relation between the real offset parameter and the sensitivity parameter and the deviation and temperature among the calculated offset parameter and sensitivity parameter, and obtaining a correction coefficient; In the production stage, conventional production calibration equipment is used for only collecting pressure data of the calibration point of the temperature section above zero, a calibration coefficient is calculated and burnt into a signal conditioning chip, when the signal conditioning chip works at the temperature below zero, an offset parameter and a sensitivity parameter are calculated by using the calibration coefficient, then the offset parameter and the sensitivity parameter are subjected to secondary correction according to the correction coefficient, and then the corrected parameters are used for pressure calibration.
2. 2. A method of calibrating pressure based on conventional production calibration equipment for full temperature segments as claimed in claim 1, wherein the zero temperature segment calibration points comprise 3 temperature points and 4 pressure points.
3. 3. A method of calibrating pressure usable in full temperature range based on conventional production calibration equipment according to claim 2, wherein the 3 temperature points comprise reference temperature point 25 ℃, low temperature point 5 ℃ and high temperature point 85 ℃ or 125 ℃, and the 4 pressure points comprise minimum range pressure point, maximum range pressure point and middle two equally spaced pressure points.
4. 4. A method for calibrating pressure based on conventional production calibration equipment for full temperature range according to claim 1, wherein the two sub-zero temperature points cover the lowest temperature point of chip operation, including the lowest temperature point of chip operation and 1/2 temperature point of the lowest temperature point.
5. 5. The method for calibrating pressure based on conventional production calibration equipment and applicable to full temperature range according to claim 1, wherein the number of samples of MEMS sensitive elements collected in the laboratory stage is not less than 50.
6. 6. The method for calibrating pressure based on conventional production calibration equipment for full temperature range according to claim 1, wherein the modeling of the relation between the actual offset parameter, the sensitivity parameter and the calculated offset parameter, the deviation between the sensitivity parameter and the temperature is a first order equation modeling the deviation as a temperature difference between a current temperature and a reference temperature.
7. 7. The method for calibrating the pressure based on the conventional production calibration equipment and applicable to the full-temperature section according to claim 1, wherein when the signal conditioning chip works at the temperature of zero, the pressure is calibrated directly by using the calibration coefficient without secondary correction.

Description

Pressure calibration method based on conventional production calibration equipment and applicable to full-temperature section Technical Field The invention relates to the technical field of pressure calibration, in particular to a pressure calibration method based on conventional production calibration equipment and applicable to a full-temperature section. Background Existing pressure sensor full temperature segment calibration techniques typically require data acquisition throughout a temperature range that encompasses the operating range of the sensor, including both the high temperature zero segment and the low temperature zero segment. Specifically, in the prior art, a MEMS (pressure sensor) sensing element to be calibrated is often required to be placed in a high-low temperature test box, traversal acquisition is performed from a lowest working temperature below zero to a highest working temperature above zero according to a set temperature point and a set pressure point, after sufficient original data are acquired, calibration coefficients (such as zero drift, sensitivity and nonlinear compensation coefficients) of a full-temperature section are calculated through a fitting algorithm, and the coefficients are burnt into a signal conditioning chip. However, the prior art solution has obvious technical problems that the full temperature section calibration has extremely high requirements on production equipment and low efficiency. Since conventional production calibration equipment (e.g., batch calibration tables) typically have only heating capabilities or are limited in cost and volume, it is difficult to provide a stable sub-zero low temperature environment (e.g., -40 ℃ or less). Therefore, in order to realize full-temperature section calibration, the existing scheme has to rely on an expensive high-low temperature alternating test box to perform single-piece or small-batch test, which not only results in high input cost and large occupied space of calibration equipment, but also takes long time in the temperature rising and falling process, severely restricts the production beat, and cannot meet the requirements of low cost and high efficiency in large-scale industrial production. If the calibration is performed on the zero temperature section by using conventional equipment, the problem that the accuracy is greatly reduced or even the sensor is invalid due to the lack of effective compensation when the sensor works on the zero temperature section is caused. Disclosure of Invention The invention aims to provide a pressure calibration method based on conventional production calibration equipment and applicable to all-temperature sections, and adopts a dual-stage strategy of laboratory depth modeling and production rapid calibration, so that the technical problems of high production cost and low efficiency caused by severe dependence on expensive high-low temperature equipment in the existing all-temperature section pressure calibration are effectively solved. In order to achieve the purpose, the technical scheme adopted by the invention is that the pressure calibration method based on conventional production calibration equipment and applicable to the full temperature section comprises the following steps of: according to the calibration requirement, determining the temperature and pressure values of the calibration points of the zero temperature section to be acquired; in the laboratory stage, acquiring zero pressure and maximum pressure data of two sub-zero temperature points of a plurality of MEMS sensitive elements in the same batch in addition to the zero temperature segment calibration point data; Calculating calibration coefficients of all pieces of MEMS sensitive elements according to the above-zero temperature segment calibration point data, and calculating offset parameters and sensitivity parameters of the two below-zero temperature points by using the calibration coefficients; According to the data acquired by the two temperature points below zero, calculating the real offset parameter and the sensitivity parameter of each piece of MEMS sensitive element, modeling the relation between the real offset parameter and the sensitivity parameter and the deviation and temperature among the calculated offset parameter and sensitivity parameter, and obtaining a correction coefficient; In the production stage, conventional production calibration equipment is used for only collecting pressure data of the calibration point of the temperature section above zero, a calibration coefficient is calculated and burnt into a signal conditioning chip, when the signal conditioning chip works at the temperature below zero, an offset parameter and a sensitivity parameter are calculated by using the calibration coefficient, then the offset parameter and the sensitivity parameter are subjected to secondary correction according to the correction coefficient, and then the corrected parameters are used for pressure