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CN-122002689-A - Precise temperature control method for components on circuit board

CN122002689ACN 122002689 ACN122002689 ACN 122002689ACN-122002689-A

Abstract

The invention relates to the technical field of electronic equipment heat management and discloses a precise temperature control method for components on a circuit board, which comprises the following steps of executing multidimensional state synchronous sampling by a vertical conduction structure of a heat conduction via hole and a shielding shell to obtain shell temperature, environment temperature and load current; the current data is processed by utilizing amplitude domain decision filtering, the instantaneous thermal power is calculated, the current data is substituted into a discretized thermal resistance-thermal capacity observer model to calculate the virtual junction temperature of the to-be-controlled temperature component in real time, the control logic calculates the total thermal regulation power by adopting a strategy of combining virtual junction temperature feedback and power feedforward, and the target driving current is directly solved based on a thermodynamic inverse physical model to drive the semiconductor refrigerating sheet or heating film to work. According to the invention, the physical conduction hysteresis is calculated and compensated through the observer, and the dynamic response speed and the steady-state control precision aiming at load step are obviously improved by matching with the self-adaptive calibration of the thermal resistance parameter.

Inventors

  • MA XINPENG
  • Gan nan
  • MOU YAJIE
  • GAO WENBIN

Assignees

  • 中国科学院高能物理研究所

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. The precise temperature control method for the components on the circuit board is characterized by comprising the following steps of: Executing multidimensional state synchronous sampling, and synchronously collecting the shell temperature, the ambient temperature and the original value of the load current of the temperature-controlled component (4) of the metal shielding heat conduction shell (2); Preprocessing the original value of the load current, calculating the instantaneous thermal power, and calculating the virtual junction temperature of the to-be-controlled temperature component (4) by using a discretized thermal resistance-thermal capacity observer model and taking the shell temperature of the metal shielding heat conducting shell (2) and the instantaneous thermal power as input variables; Calculating a feedback control quantity according to the deviation between the virtual junction temperature and the set temperature, calculating a feedforward control quantity according to the instantaneous thermal power, and superposing the two to obtain total thermal regulation power; And the total heat regulation power is converted into target driving current according to a reverse physical model to drive the semiconductor refrigerating sheet or heating film (3) to work based on the boundary condition that the heat radiation efficiency of the heat radiation sheet (7) is high enough to enable the temperature of the hot end of the semiconductor refrigerating sheet or heating film (3) to be approximately equal to the ambient temperature.
  2. 2. The precise temperature control method for components on a circuit board according to claim 1, wherein a temperature control system is provided with a determined vertical heat conduction channel, the components (4) to be controlled are welded on the top layer of the printed circuit board (1) through a surface mounting process, a bottom heat dissipation pad area is connected to a grounding heat conduction layer of the inner layer of the printed circuit board (1) through a heat conduction via hole array, the grounding heat conduction layer is configured to diffuse heat to an installation projection area of the metal shielding heat conduction shell (2) along the horizontal direction, the metal shielding heat conduction shell (2) is buckled and installed and connected with the grounding heat conduction layer in a heat conduction mode, and the outer side of the top surface of the metal shielding heat conduction shell (2) is in heat exchange with the semiconductor refrigerating sheet or the heating film (3) through a heat conduction interface material.
  3. 3. The precise temperature control method for components on a circuit board according to claim 1, wherein the preprocessing the original value of the load current comprises performing a nonlinear filtering step based on an amplitude domain decision: calculating the absolute deviation between the original value of the load current at the current moment and the effective current value at the previous moment; When the absolute deviation is smaller than a preset noise threshold, judging that the current change is noise fluctuation, and executing low-pass filtering operation, namely carrying out weighted summation on the effective current value at the previous moment and the original load current value at the current moment so as to update the effective current value at the current moment; when the absolute deviation is larger than or equal to the preset noise threshold, judging that the current changes into a load step, and executing straight-through operation, namely directly assigning the load current original value at the current moment to the effective current value at the current moment; The instantaneous thermal power is calculated according to the product of the effective current value at the current time and the power supply voltage of the temperature component (4) to be controlled.
  4. 4. The precise temperature control method for components on a circuit board according to claim 1, wherein the calculating of the virtual junction temperature of the components to be controlled (4) is performed according to a state update equation of the observer model, and the calculating logic is as follows: Calculating a temperature rise increment based on the instant thermal power at the previous moment, and calculating a heat flow dissipation amount based on the temperature difference between the estimated junction temperature at the previous moment and the shell temperature at the previous moment and the equivalent thermal resistance parameter at the previous moment; And scaling the difference value between the temperature rise increment and the heat flow dissipation quantity by using the ratio of the control period to the equivalent heat capacity, and overlapping the scaled result to the estimated junction temperature at the previous moment to obtain the estimated junction temperature at the current moment.
  5. 5. The method for precisely controlling the temperature of components on a circuit board according to claim 1, further comprising the step of adaptively calibrating model parameters: Judging whether the temperature control system is in a thermal steady state or not, wherein the criterion of the thermal steady state comprises that the absolute value of the deviation between the set temperature and the shell temperature is smaller than a preset steady state error limit, the change rate of load current is smaller than a preset change rate threshold value, and the duration exceeds a preset time window; if the thermal steady-state condition is met, reading an integral term accumulation value for calculating the feedback control quantity; And if the deviation between the integral term accumulation value and the integral reference value exceeds a threshold value, carrying out iterative correction on the equivalent thermal resistance parameter by using a calibration enabling coefficient and an adjustment step length according to the sign direction of the deviation so as to compensate the aging drift of the physical thermal resistance.
  6. 6. The precise temperature control method of components on a circuit board according to claim 1, wherein the calculating of the feedback control amount is performed based on a proportional-integral-derivative control algorithm, the calculating of the feedforward control amount is performed based on a product of the instantaneous thermal power and a feedforward gain coefficient, and the total thermal regulation power is an algebraic sum of the feedback control amount and the feedforward control amount.
  7. 7. The method for precisely controlling the temperature of components on a circuit board according to claim 1, wherein the converting the total thermal regulation power into the target driving current according to the inverse physical model comprises: establishing a unitary quadratic equation for a target drive current, the equation describing the relationship between the endothermic or exothermic power of the semiconductor refrigeration sheet or heating film (3) and the current, and parameters of the equation including the seebeck coefficient, the internal resistance of the semiconductor refrigeration sheet or heating film (3), the heat conductivity coefficient, the shell temperature of the metal shielding heat conducting shell (2), the ambient temperature and the total heat regulation power; solving the unitary quadratic equation, and selecting a solution which enables the semiconductor refrigeration piece or the heating film (3) to work in a high energy efficiency area from two mathematical solutions as the target driving current.
  8. 8. The precise temperature control method for components on a circuit board according to claim 1, further comprising a dew point protection step of calculating a dew point temperature according to the ambient temperature and the relative humidity, and limiting the amplitude of the target driving current to prevent dew condensation on the surface of the metal shielding heat conducting shell (2) if the cold end temperature corresponding to the target driving current is lower than the sum of the dew point temperature and a safety margin.
  9. 9. The precise temperature control method of components on a circuit board according to claim 2, wherein the multi-dimensional state synchronous sampling is performed by a sensing detection module, the sensing detection module comprising: the load current sampling unit is connected in series with the direct current power supply input end of the temperature component (4) to be controlled and comprises a precise shunt resistor and a differential amplifier; The first temperature probe (9) is mounted close to the metal shielding heat conduction shell (2) and is used for collecting the shell temperature of the metal shielding heat conduction shell (2); the second temperature probe (9) is arranged at the edge of the printed circuit board (1) and is used for collecting the ambient temperature; wherein the metal shielding heat conducting shell (2) is mechanically fixed to the radiating fins (7) or an external structure by heat insulation studs (6), and the heat insulation studs (6) are configured to block heat transfer paths except the semiconductor refrigerating sheets or the heating films (3).
  10. 10. The precise temperature control method of components on a circuit board according to claim 1, wherein the driving of the semiconductor refrigeration piece or the heating film (3) is performed by a power driving circuit, the power driving circuit adopts a linear adjustment topology comprising a digital-to-analog converter and a power transistor working in a linear amplifying region, and an output end of a microcontroller is connected to the semiconductor refrigeration piece through a heating/refrigeration power line (5) or connected to the heating film through a heating power line (8) to output continuous and switching noise-free driving current.

Description

Precise temperature control method for components on circuit board Technical Field The invention relates to the technical field of thermal management of electronic equipment, in particular to a precise temperature control method for components on a circuit board. Background In the technical field of precision electronics, core components such as an optical communication laser, an infrared detector, a high-precision reference voltage source and the like, the working performance of the components is extremely sensitive to temperature change, and tiny temperature fluctuation can cause wavelength drift, signal-to-noise ratio deterioration or output precision reduction, and the index of the whole machine is seriously influenced, so that strict temperature management is implemented on the key components, so that the components work in a constant and accurate temperature environment, and the conditions of stable performance and reliable data of high-end electronic equipment are ensured. The prior component temperature control scheme generally adopts a closed loop feedback control architecture and mainly comprises a temperature sensor, a control unit and an execution component, the conventional technical implementation mode is to attach a thermistor (such as NTC or PT 100) to the surface of a radiator or a circuit board area close to a component to be controlled in order to acquire real-time temperature, the control unit reads the temperature value and compares the temperature value with a set target value, and the control unit calculates an adjustment quantity by utilizing a proportional-integral-derivative algorithm, so as to adjust the driving current of a semiconductor refrigerating sheet or a heating film in a pulse width modulation or linear driving mode, and maintain the temperature stability of the component by changing heat exchange power. Although the prior art can meet the general temperature control requirement under the steady-state working condition, the prior art still has obvious defects when facing the rapid change of load or the high-precision requirement, as the physical position of the temperature sensor is positioned outside the component or on the radiator and the thermal resistance and the heat capacity formed by the packaging shell, the welding layer and the medium exist between the heating wafer and the heating wafer inside the component, the physical time delay exists in heat transfer, when the working load of the component generates step change to cause the instantaneous fluctuation of the internal junction temperature, the external sensor needs to wait for the thermal diffusion to sense the temperature change, the inherent detection lag enables the controller to not respond at the first time, thereby causing obvious overshoot or undershoot of the junction temperature, in addition, the heat pump efficiency of the executing component such as a semiconductor refrigerating sheet is provided with nonlinear characteristics, and the influence of temperature difference is larger, and the traditional linear pulse width modulation algorithm is difficult to precisely match the nonlinear physical characteristics, the problem of oscillation or the overlong convergence time is easy to be generated in the adjusting process, meanwhile, the interface material ageing can cause the contact thermal resistance to drift along with the long-term running of the equipment, the control model of the fixed parameter can not automatically respond to the first time, the thermal conductivity control is further influenced, and the long-term heat conduction precision control is kept. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a precise temperature control method for components on a circuit board, which solves the problems of sensor response lag, insufficient control precision and temperature overshoot caused by thermal inertia in the temperature control scheme of components on the circuit board in the prior art. The method comprises the following steps of executing multidimensional state synchronous sampling, synchronously collecting shell temperature, ambient temperature and a load current original value of a component to be controlled, preprocessing the load current original value and calculating instant thermal power, calculating virtual junction temperature of the component to be controlled by using a discretized thermal resistance-thermal capacity observer model, calculating feedback control quantity according to deviation of the virtual junction temperature and the instant thermal power, calculating feedforward control quantity according to the instant thermal power, superposing the two to obtain total thermal regulation power, and converting the total thermal regulation power into target driving current according to a reverse physical model based on the heat dissipation efficiency of a radiating fin meeting the boundary condition that the hot end temperature of a semico