An anti-interference thermocouple acquisition circuit for semiconductor pipe temperature controllers

Abstract

This utility model relates to the field of temperature detection technology, specifically to an anti-interference thermocouple acquisition circuit for semiconductor pipeline temperature controllers. It includes a signal acquisition module, a differential signal conversion module, and a signal processing module connected in sequence. The signal acquisition module acquires the original voltage signal of the thermocouple and may include precision resistor-capacitor components for preliminary filtering. The differential signal conversion module converts the original voltage signal into a differential signal with strong anti-interference capability. The signal processing module processes the differential signal and outputs a stable and accurate temperature measurement value. This utility model, through improvements to the circuit module structure, changes the easily interfered single-ended signal transmission method to differential signal transmission, significantly improving anti-interference capability and detection stability in complex electromagnetic environments. Simultaneously, the use of precision components ensures detection accuracy, making it particularly suitable for high-precision temperature control in semiconductor production pipelines.

Description

Technical Field

[0001] This utility model relates to the field of temperature detection technology, and in particular to an anti-interference thermocouple acquisition circuit for monitoring the temperature of pipelines in semiconductor manufacturing processes. Background Technology

[0002] In semiconductor manufacturing, accurate and stable real-time monitoring of the temperature across various process pipelines is a crucial step in ensuring chip yield. Thermocouples are widely used for temperature sensing in such high-temperature environments due to their wide measurement range and stable performance.

[0003] However, the inventors discovered that traditional thermocouple acquisition circuits have significant drawbacks in practical applications, especially in complex industrial environments. Traditional circuits often employ single-ended signal acquisition methods (e.g., transmitting signals in the form of duty cycle signals or single-ended voltage signals), which have poor common-mode noise suppression capabilities. Semiconductor factories contain numerous high-frequency interference sources, such as walkie-talkies used by workers, high-power motors, and frequency converters. The electromagnetic waves generated by these devices couple into the thermocouple leads and acquisition circuits, creating common-mode interference. This interference superimposed on the weak thermocouple voltage signal causes temperature readings to fluctuate and drift, and in severe cases, even become completely inaccurate, directly affecting the stability of semiconductor processes and product consistency.

[0004] Therefore, there is an urgent need in the existing technology for thermocouple acquisition circuits with high anti-interference capability and high precision. Utility Model Content

[0005] Purpose of this utility model: To provide an anti-interference thermocouple acquisition circuit for semiconductor pipeline temperature controllers, thereby solving the aforementioned problems.

[0006] Technical solution: An anti-interference thermocouple acquisition circuit for semiconductor pipeline temperature controllers, comprising: a signal acquisition module, a differential signal module, a conversion module, and a signal processing module;

[0007] The signal acquisition module is used to connect to the thermocouple to acquire the raw voltage signal generated by the thermocouple;

[0008] The differential signal module is electrically connected to the signal acquisition module and is used to convert the original voltage signal into a differential signal;

[0009] The conversion module is electrically connected to the differential signal conversion module and is used to convert the differential signal into a digital signal;

[0010] The signal processing module is electrically connected to the conversion module and is used to receive and process the digital signal to output a stable temperature measurement value.

[0011] In a further embodiment, the signal acquisition module includes an analog switch, a precision resistor, and a precision capacitor, which constitute a filter circuit for preliminary filtering of the original voltage signal.

[0012] In a further embodiment, the differential signal module includes a differential amplifier for generating the differential signal.

[0013] In a further embodiment, the conversion module includes an analog-to-digital converter for converting the differential signal into a digital signal.

[0014] In a further embodiment, the signal processing module is a microcontroller with built-in programs for further digital filtering of the digital signal (such as mean filtering, Kalman filtering, etc.) and temperature conversion based on the thermocouple calibration table.

[0015] In a further embodiment, the circuit is entirely housed within a shielded housing, which is grounded, to further enhance protection against external radiation interference.

[0016] In a further embodiment, the signal acquisition module includes: a rectifier E3, a first capacitor C20, a ferrite bead R14, an analog switch U13, a second capacitor C21, and a first resistor R23;

[0017] One end of the rectifier E3 is connected to one end of the first capacitor C21 and one end of the ferrite bead R14 and inputs the signal TC1+ / T1+. Pin 1 of the analog switch U13 is connected to the other end of the ferrite bead R14. Pin 2 of the analog switch U13 is grounded. Pin 3 of the analog switch U13 is connected to the other end of the rectifier E3 and one end of the first capacitor C20 and is grounded. Pin 4 of the analog switch U13 is connected to one end of the second capacitor C21 and one end of the first resistor R23. Pin 5 of the analog switch U13 inputs the operating voltage. Pin 6 of the analog switch U13 inputs the switch signal S1. The other end of the second capacitor C21 is grounded.

[0018] In a further embodiment, the differential signal module includes: a differential amplifier U9, a second resistor R40, a third resistor R38, a fourth resistor R39, a fifth resistor R33, and a third capacitor C19;

[0019] Pin 3 of the differential amplifier U9 is connected to the other end of the first resistor R23. Pin 2 of the differential amplifier U9 is grounded. Pin 5 of the differential amplifier U9 receives the operating voltage. Pin 4 of the differential amplifier U9 is connected to one end of the second resistor R40 and one end of the third resistor R38. Pin 1 of the differential amplifier U9 is connected to the other end of the third resistor R38, one end of the fourth resistor R39, and one end of the fifth resistor R33. The other end of the fifth resistor R33 is connected to one end of the third capacitor C19 and outputs a differential signal to the conversion module. The other ends of the second resistor R40, the fourth resistor R39, the fifth resistor R33, and the third capacitor C19 are grounded.

[0020] Compared with the prior art, the thermocouple acquisition circuit provided by this utility model has the following significant advantages:

[0021] 1. Strong anti-interference capability: The core innovation of this invention lies in the introduction of a differential signal conversion module, which converts the susceptible single-ended signal into a differential signal for transmission. Differential signals have a natural suppression effect on common-mode noise (such as high-frequency interference generated by walkie-talkies), effectively filtering out interference voltages that commonly appear on the signal line, thereby ensuring the purity of the signal during transmission and solving the core problems of reading jumps and instability.

[0022] 2. High Detection Accuracy: By using precision resistors and capacitors in the signal acquisition module, the accuracy and low drift characteristics of the front-end signal conditioning are ensured. These high-precision components reduce the variation of their own parameters with temperature and time, providing a high-quality signal source for subsequent differential conversion and processing, thereby improving the overall accuracy of temperature detection.

[0023] 3. Good system stability: Combining the anti-interference advantages of differential signals and the digital filtering algorithm of the signal processing module, this invention can output extremely stable temperature measurement values, greatly reducing the risk of false alarms or system malfunctions caused by external interference, and is particularly suitable for semiconductor manufacturing environments that require continuous and stable production.

[0024] 4. High practicality: This utility model achieves its effect through modular hardware circuit improvement. It has a clear structure and is easy to integrate into existing temperature controllers or data acquisition systems, and has good industrial application value. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the module structure of this utility model.

[0026] Figure 2 This is a schematic diagram of the structure of this utility model including the shielding shell.

[0027] Figure 3 This is a circuit diagram of the signal acquisition module and differential signal module of this utility model. Detailed Implementation

[0028] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] Example 1

[0032] like Figure 1 As shown, the present invention provides an anti-interference thermocouple acquisition circuit for semiconductor pipeline temperature control, which mainly includes three functional modules: a signal acquisition module, a differential signal module, a conversion module, and a signal processing module.

[0033] In practical applications, the two leads of the thermocouple are connected to the input terminal of the signal acquisition module. The signal acquisition module contains an RC low-pass filter network composed of precision resistors and precision capacitors, which can perform preliminary filtering on the weak millivolt-level voltage signal generated by the thermocouple, filtering out some high-frequency noise.

[0034] The pre-filtered signal is fed into the differential signal module and the conversion module. At the heart of both modules is a differential amplifier chip (such as the INA series), which converts the single-ended input signal into a pair of differential signals (V+ and V-). Subsequently, a high-precision analog-to-digital converter converts this pair of differential signals into digital values. This process is crucial because any common-mode interference superimposed on both signal lines is significantly suppressed by the differential amplifier.

[0035] The converted digital signal is transmitted to the signal processing module 103 via a bus such as SPI or I2C. This module is typically a microcontroller. The microcontroller runs embedded software to perform software filtering on the received digital signal and consults the internally stored thermocouple temperature-voltage correspondence table (calibration table) to calculate the accurate temperature value, which is then output to the host computer or display unit.

[0036] Example 2

[0037] Based on Example 1, such as Figure 2 As shown, to cope with extremely harsh electromagnetic environments, the entire thermocouple acquisition circuit (i.e., signal acquisition module, differential signal module, conversion module, and signal processing module) can be installed inside a shielded metal enclosure. The shielded enclosure is reliably connected to the system's grounding terminal via a wire. In this way, electromagnetic waves radiated from the external space (such as walkie-talkie signals) will be blocked by the shielded enclosure and conducted to the ground, preventing them from intruding into the internal circuitry, thus providing double protection.

[0038] Example 3

[0039] In another implementation, the signal acquisition module can be further integrated with an instrumentation amplifier to amplify the thermocouple signal with high impedance and low noise before sending it to the differential signal module and conversion module. This is particularly advantageous for applications involving the measurement of minute temperature differences.

[0040] Example 4

[0041] The signal acquisition module includes: rectifier E3, first capacitor C20, ferrite bead R14, analog switch U13, second capacitor C21 and first resistor R23;

[0042] One end of the rectifier E3 is connected to one end of the first capacitor C21 and one end of the ferrite bead R14 and inputs the signal TC1+ / T1+. Pin 1 of the analog switch U13 is connected to the other end of the ferrite bead R14. Pin 2 of the analog switch U13 is grounded. Pin 3 of the analog switch U13 is connected to the other end of the rectifier E3 and one end of the first capacitor C20 and is grounded. Pin 4 of the analog switch U13 is connected to one end of the second capacitor C21 and one end of the first resistor R23. Pin 5 of the analog switch U13 inputs the operating voltage. Pin 6 of the analog switch U13 inputs the switch signal S1. The other end of the second capacitor C21 is grounded.

[0043] The differential signal module includes: a differential amplifier U9, a second resistor R40, a third resistor R38, a fourth resistor R39, a fifth resistor R33, and a third capacitor C19;

[0044] Pin 3 of the differential amplifier U9 is connected to the other end of the first resistor R23. Pin 2 of the differential amplifier U9 is grounded. Pin 5 of the differential amplifier U9 receives the operating voltage. Pin 4 of the differential amplifier U9 is connected to one end of the second resistor R40 and one end of the third resistor R38. Pin 1 of the differential amplifier U9 is connected to the other end of the third resistor R38, one end of the fourth resistor R39, and one end of the fifth resistor R33. The other end of the fifth resistor R33 is connected to one end of the third capacitor C19 and outputs a differential signal to the conversion module. The other ends of the second resistor R40, the fourth resistor R39, the fifth resistor R33, and the third capacitor C19 are grounded.

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. An anti-interference thermocouple acquisition circuit for a semiconductor pipe temperature controller, characterized in that, include: Signal acquisition module, differential signal module, conversion module and signal processing module; The signal acquisition module is used to connect to the thermocouple to acquire the raw voltage signal generated by the thermocouple; The differential signal module is electrically connected to the signal acquisition module and is used to convert the original voltage signal into a differential signal; The conversion module is electrically connected to the differential signal conversion module and is used to convert the differential signal into a digital signal; The signal processing module is electrically connected to the conversion module and is used to receive and process the digital signal to output a stable temperature measurement value.

2. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 1, characterized in that, The signal acquisition module includes an analog switch, a precision resistor, and a precision capacitor. The precision resistor and precision capacitor constitute a filter circuit for preliminary filtering of the original voltage signal.

3. An anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to any one of claims 1 or 2, characterized in that, The differential signal module includes a differential amplifier, which is used to generate the differential signal.

4. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 1, characterized in that, The conversion module includes an analog-to-digital converter, which is used to convert the differential signal into a digital signal.

5. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 4, characterized in that, The signal processing module is a microcontroller configured to perform digital filtering and temperature conversion on the digital signal.

6. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 1, characterized in that, The entire circuit is housed within a shielded enclosure, which is grounded.

7. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 1, characterized in that, The signal acquisition module includes: rectifier E3, first capacitor C20, ferrite bead R14, analog switch U13, second capacitor C21 and first resistor R23; One end of the rectifier E3 is connected to one end of the first capacitor C21 and one end of the ferrite bead R14 and inputs the signal TC1+ / T1+. Pin 1 of the analog switch U13 is connected to the other end of the ferrite bead R14. Pin 2 of the analog switch U13 is grounded. Pin 3 of the analog switch U13 is connected to the other end of the rectifier E3 and one end of the first capacitor C20 and is grounded. Pin 4 of the analog switch U13 is connected to one end of the second capacitor C21 and one end of the first resistor R23. Pin 5 of the analog switch U13 inputs the operating voltage. Pin 6 of the analog switch U13 inputs the switch signal S1. The other end of the second capacitor C21 is grounded.

8. The anti-interference thermocouple acquisition circuit for a semiconductor pipeline temperature controller according to claim 7, characterized in that, The differential signal module includes: a differential amplifier U9, a second resistor R40, a third resistor R38, a fourth resistor R39, a fifth resistor R33, and a third capacitor C19; Pin 3 of the differential amplifier U9 is connected to the other end of the first resistor R23. Pin 2 of the differential amplifier U9 is grounded. Pin 5 of the differential amplifier U9 receives the operating voltage. Pin 4 of the differential amplifier U9 is connected to one end of the second resistor R40 and one end of the third resistor R38. Pin 1 of the differential amplifier U9 is connected to the other end of the third resistor R38, one end of the fourth resistor R39, and one end of the fifth resistor R33. The other end of the fifth resistor R33 is connected to one end of the third capacitor C19 and outputs a differential signal to the conversion module. The other ends of the second resistor R40, the fourth resistor R39, the fifth resistor R33, and the third capacitor C19 are grounded.

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