System and method for precisely measuring heat conduction performance of vapor chamber

Abstract

The invention aims to provide the system and the method for precisely measuring the heat conduction performance of the vapor chamber, which can eliminate errors caused by contact thermal resistance by utilizing the vapor chamber, and is high in spatial resolution and non-destructive in test. The uniform temperature plate heat conduction performance precision measurement system comprises a temperature measurement module, the temperature measurement module comprises a heating module and a plurality of measurement modules, each measurement module comprises a thermocouple probe and a force adjusting mechanism which are connected, and each thermocouple probe comprises a T-shaped thermocouple, a positive electrode temperature measurement pressure head and a negative electrode temperature measurement pressure head. The positive temperature measuring pressure head and the negative temperature measuring pressure head are mutually independent and are arranged in a floating mode relative to the force adjusting mechanism, the positive temperature measuring pressure head is provided with a copper thermocouple wire connected to the positive electrode of the T-type thermocouple, and the negative temperature measuring pressure head is provided with a constantan thermocouple wire connected to the negative electrode of the T-type thermocouple. The copper thermocouple wire and the constantan thermocouple wire are short-circuited and form a thermocouple loop when being in contact with the vapor chamber at the same time; the method is realized based on the measurement system. The method is applied to the technical field of vapor chamber testing.

Description

Technical Field

[0001] The present invention is applied to the technical field of temperature averaging board testing, and particularly relates to a system and method for accurately measuring the thermal conductivity performance of a temperature averaging board. Background Art

[0002] The temperature spreader is used for heat conduction of heat-generating components such as processing chips, power supplies, and metal casings in smart products such as mobile phones. The temperature spreader itself has the characteristic of rapid heat dissipation. At present, according to the structure of smart products, the size of the temperature spreader is about 75~80mm long, 25~30mm wide, and 0.3mm thick. Copper is usually used as the material, and the interior is a vacuum capillary structure. In order to ensure that the performance of the temperature spreader can meet the heat dissipation requirements of smart products, it is necessary to measure the thermal conductivity performance of the temperature spreader. Common measurement methods in the industry mainly revolve around thermal resistance testing, temperature field analysis, and dynamic thermal response, mainly including: 1. Thermal resistance test method; 2. Infrared thermal imaging method; 3. Laser speckle dynamic thermal analysis; 4. Thermocouple array contact temperature measurement. Among them, the thermal resistance test method evaluates thermal resistance by measuring the ratio of the temperature difference ΔT at both ends of the temperature equalizer to the input power P. A heating plate is attached to the heat source surface of the temperature equalizer, and the cold end is connected to a radiator or a water-cooled plate. A single-point thermocouple or thermistor is used to measure the temperature of the heat source surface and the cold end. Its limitation is that it cannot reflect the "temperature uniformity" characteristics of the temperature equalizer, and can only evaluate the overall thermal resistance. In addition, there are also problems such as contact thermal resistance error and inapplicability to dynamic heat diffusion. The thermal infrared imaging method uses an infrared thermal imager to non-contactly scan the temperature field on the surface of the temperature equalizer to generate a thermal distribution map; its typical solution is to spray a high-emissivity coating such as graphene coating on the surface of the temperature equalizer, and after applying a constant heat source, use an infrared camera to record the temperature distribution. Its limitation is that the coating may change the heat transfer characteristics of the surface of the temperature equalizer, resulting in measurement distortion. In addition, it is also limited by the progress of the infrared camera, and the dynamic response speed is not fast enough. Laser speckle dynamic thermal analysis uses laser speckle interferometry to detect tiny deformations of the heat spreader after heating, and infer the thermal conductivity performance. Specifically, a transient heat pulse such as laser heating is applied to the heat spreader, and the thermal expansion rate is calculated through speckle displacement to indirectly evaluate the thermal conductivity efficiency. Its limitations are measurement errors, high equipment costs, and high scene requirements that make it difficult to meet the needs of rapid testing on the production line. Thermocouple array contact temperature measurement is to arrange multiple thermocouples such as K-type or T-type on the surface of the heat spreader to measure multiple temperatures simultaneously, but it is necessary to use adhesives or mechanical clamps to fix the thermocouple probes, and then record the temperature changes through a multi-channel data acquisition system. Its limitations are that adhesives or clamps will introduce additional thermal resistance, reduce measurement accuracy, and the probe size leads to low detection resolution and delayed response speed. At the same time, the setting of the fixture during measurement can easily cause the heat spreader to deform and cause damage.

[0003] If a precision measurement system and method for the heat conduction performance of a heat pipe with small error, high spatial resolution, and non-destructive testing can be provided, the technical problems of the above measurement method can be well solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a precision measurement system and method for the heat conduction performance of a heat pipe that uses the heat pipe itself to eliminate the error caused by contact thermal resistance, while having high spatial resolution and non-destructive testing.

[0005] The technical solution adopted by the present invention is as follows: The present invention includes a temperature measurement module, the temperature measurement module includes a heating module and a plurality of measurement modules, the measurement module includes a thermocouple probe and a force adjustment mechanism connected to each other, the heating module is arranged in a jig, the thermocouple probe includes a T-type thermocouple, a positive temperature measurement pressure head, and a negative temperature measurement pressure head, the positive temperature measurement pressure head and the negative temperature measurement pressure head are independent of each other and are floatingly arranged relative to the force adjustment mechanism, a copper wire connected to the positive pole of the T-type thermocouple is arranged on the positive temperature measurement pressure head, a constantan wire connected to the negative pole of the T-type thermocouple is arranged on the negative temperature measurement pressure head, and the copper wire and the constantan wire are short-circuited and form a thermocouple circuit when they contact the heat pipe at the same time.

[0006] As can be seen from the above solution, by measuring temperature through thermocouple contact and using the heat pipe as an intermediate conductor, the surface of the heat pipe can be directly measured, eliminating the contact thermal resistance introduced by adhesives / welding in traditional thermocouple tests. And a force adjustment mechanism is set to drive the thermocouple probe, thereby realizing force control to avoid deformation of the heat pipe and protecting the heat pipe from damage. In addition, through the heating module, active constant-power heating is realized, and multiple groups of measurement modules are used to collect multi-point data on the heat pipe, so as to obtain a more comprehensive measurement of the heat conduction performance of the heat pipe, and at the same time, it is convenient to evaluate the position of heat accumulation defects on the heat pipe.

[0007] A preferred solution is that a plurality of the measurement modules are arranged in a non-equidistant layout.

[0008] A preferred solution is that a total of five groups of the measurement modules are provided, the first group of measurement modules and the fifth group of measurement modules are arranged in parallel, and the distance ratio between adjacent modules of the first group of measurement modules, the second group of measurement modules, the third group of measurement modules, and the fourth group of measurement modules is 3:4:3.

[0009] One preferred solution is that the heating module includes a constant power output unit and a ceramic heating sheet. The ceramic heating sheet is arranged in the fixture and is in contact and cooperation with the heat dissipation plate. The constant power output unit includes a power supply component, a DAC digital-to-analog converter, an ADC analog-to-digital converter, a PID power control loop, a voltage loop, a current loop, and a multiplier. The power supply component is used to convert the input power supply into the voltages required for the operation of each component. The DAC digital-to-analog converter includes two output channels. One output channel is used to control the voltage comparison sampling of the power supply component, and the other output channel is used to control the power setting of the PID power control loop. The ADC analog-to-digital converter is used to convert the voltage signals of the voltage loop and the current loop. The MCU unit communicates with the ADC analog-to-digital converter to read the voltage U and current I signals of the control loop. The voltage loop is used to sample the voltage signal at the load end. The current loop is used for current signal sampling, and the amplified current signal will be used as the feedback signal for constant power. The multiplier selects the AD633 multiplier with four-quadrant, differential high-impedance X / Y inputs to implement the power arithmetic unit, and the multiplier is used for calculation. The PID power control loop performs constant power PID adjustment to make the ceramic heating sheet always operate in a constant power state.

[0010] One preferred solution is that the force adjustment mechanism includes a voice coil actuator and a pressure sensor. The pressure sensor detects the magnitude of the pressure output by the voice coil actuator. The temperature measurement module further includes a controller electrically connected to a plurality of the force adjustment mechanisms.

[0011] One preferred solution is that the temperature measurement module further includes an acquisition module. A plurality of the T-type thermocouples are electrically connected to the acquisition module. The acquisition module includes a thermocouple signal ADC converter, a thermocouple channel switching switch, an input filter network, and a cold-junction compensation digital temperature sensor. The thermocouple signal ADC converter is used to convert and amplify the electrical signal output by the T-type thermocouple. The cold-junction compensation digital temperature sensor is used to collect the temperature of the negative terminal of the T-type thermocouple for cold-junction compensation. The thermocouple channel switching switch and the input filter network perform channel differential signal input switching.

[0012] One preferred solution is that the temperature measurement module further includes a processing module. The processing module includes an MCU unit, a power supply unit, an expansion unit, and a communication unit. The MCU unit is used for data processing and instruction transmission. The power supply unit is used for isolation processing and voltage regulation of the input voltage. The expansion unit is used for communication and control between the MCU unit and the heating module and a plurality of the measurement modules. The MCU unit communicates with an external computer through the communication unit.

[0013] A test method includes the following specific steps: Step S1: Before the test, the heating module heats its own temperature to the preheating temperature; Step S2: After the temperature of the heating module stabilizes, place the heat spreader in the fixture, and the force adjustment mechanism controls the thermocouple probe to contact the heat spreader with a set force. Each position where the thermocouple probe contacts the heat spreader is different; Step S3: After completing the contact control, the heating module switches to constant power control to simulate the continuous working state of the chip heat source; Step S4: During the process of heating to the thermal steady state, synchronously collect the temperature values of the heating module, several thermocouple probes, and the ambient temperature at regular intervals. During the measurement process, the two thermocouple wires of the thermocouple probe use the heat spreader as an intermediate conductor; Step S5: Calculate the radial temperature difference, local temperature difference, gradient temperature difference, and the surface thermal resistance of the heat spreader based on the collected data, and judge the calculation results according to the set temperature difference threshold. If all temperature difference values are lower than the temperature difference threshold, it is judged that the heat conduction performance of the heat spreader is excellent; otherwise, if any temperature difference value exceeds the temperature difference threshold, it is determined that there is a heat accumulation defect; Step S6: After completing the collection, the force adjustment mechanism controls the thermocouple probe to separate from the heat spreader.

[0014] As can be seen from the above solution, a stable initial temperature environment is provided through preheating, thereby ensuring the unity of the starting conditions for measurement. During docking, the contact force is controlled by the force adjustment mechanism, thereby avoiding damage to the relatively thin heat spreader due to excessive downward pressure during contact and during the test. Further, a stable heating rate is provided through constant power control, thereby ensuring that the heat spreader will not fluctuate due to the heat source during heating, ensuring the accuracy of the detection results. Through multi-point temperature measurement, the radial temperature, local temperature, and gradient temperature of the heat spreader are collected, and at the same time, the surface thermal resistance of the heat spreader is calculated, and the result is judged and output according to the preset standard. Description of the Drawings

[0015] Figure 1 is the system block diagram of the precise measurement system for the heat conduction performance of the heat spreader; Figure 2 is the structural schematic diagram of the cooperation between the thermocouple probe and the heat spreader; Figure 3 is the system block diagram of the heating module; Figure 4 is the system block diagram of the acquisition module; Figure 5 is the schematic diagram of the cold-junction compensation digital temperature sensor and the thermocouple probe; Figure 6 is the flowchart of the measurement method. Detailed Embodiments

[0016] As Figure 1 and Figure 2 shown, in this embodiment, the present invention includes a temperature measurement module, the temperature measurement module includes a heating module and a plurality of measurement modules, the measurement module includes a thermocouple probe 1 and a force adjustment mechanism 2 connected to each other, the heating module is arranged in a jig, the thermocouple probe 1 includes a T-type thermocouple 11, a positive temperature measurement pressure head 12 and a negative temperature measurement pressure head 13, the positive temperature measurement pressure head 12 and the negative temperature measurement pressure head 13 are independent of each other and are arranged to float relative to the force adjustment mechanism 2, a copper wire 14 connected to the positive pole of the T-type thermocouple 11 is arranged on the positive temperature measurement pressure head 12, a constantan wire 15 connected to the negative pole of the T-type thermocouple 11 is arranged on the negative temperature measurement pressure head 13, and the copper wire 14 and the constantan wire 15 are short-circuited and form a thermocouple loop when they are in contact with the heat dissipation plate at the same time. By adopting the independent floating arrangement, the balance gap caused by the contact between the thermocouple wire and the heat dissipation plate is eliminated. The copper substrate of the measured heat dissipation plate is used as the natural conductor of the copper-constantan of the T-type thermocouple 11, so as to eliminate the third conductor error introduced by traditional welding, and the temperature measurement accuracy is improved to ±0.1°C. When the thermocouple probe presses down and contacts the heat dissipation plate, the copper wire and the constantan wire are short-circuited on the heat dissipation plate. After being short-circuited, a thermocouple loop is formed. According to the Seebeck law, the temperature thermoelectric potential on the heat dissipation plate will be generated on the positive and negative electrodes of the thermocouple, and then the acquisition module 5 of the temperature measurement module amplifies this thermoelectric potential signal to realize the accurate temperature measurement of the thermocouple.

[0017] In this embodiment, the size of the heat dissipation plate is 75-80 mm in length, 25-30 mm in width, and 0.3 mm in thickness. The temperature measurement module is provided with five groups of the measurement modules. The distance between adjacent measurement modules can be equal or unequal. In this embodiment, a non-equal-spacing layout is adopted. The first group of measurement modules and the fifth group of measurement modules are arranged in parallel and share the same group of the force adjustment mechanism. The distances between adjacent modules of the first group of measurement modules, the second group of measurement modules, the third group of measurement modules, and the fourth group of measurement modules are 15 mm, 20 mm, and 15 mm in sequence. Among them, the position of the first group of measurement modules is directly opposite to the heating module, and the measured temperature value is T1. The measured temperature values of the second group of measurement modules, the third group of measurement modules, the fourth group of measurement modules, and the fifth group of measurement modules are T2, T3, T4, and T5 respectively. By taking the difference between the temperature values of two adjacent groups of measurement modules, the temperature difference value ΔT at two positions on the corresponding heat dissipation plate is obtained. By analyzing the temperature difference value, the quality of the temperature transfer performance of the heat dissipation plate is evaluated. The larger the temperature difference value, the worse the conduction and heat dissipation characteristics, and the smaller and closer the temperature difference value, the better the conduction characteristics of the heat dissipation plate.

[0018] In this embodiment, the force adjustment mechanism 2 includes a voice coil actuator 21 and a pressure sensor. The pressure sensor detects the magnitude of the pressure output by the voice coil actuator 21. The temperature measurement module further includes a controller 22 electrically connected to a plurality of the force adjustment mechanisms 2. In this embodiment, since the first group of measurement modules and the fifth group of measurement modules are arranged in parallel with a small distance between them, they share a set of voice coil actuators. The controller 22 includes a PLC controller. The controller 22 is connected to an external computer to obtain action instructions. The controller 22 collects pressure values through the pressure sensor. At the same time, the controller 22 controls the output of the power driver of the voice coil actuator through the electromagnetic force electromagnetic load current closed-loop feedback PID algorithm, so as to press the corresponding thermocouple probe onto the surface of the heat spreader with a stable contact force. In this embodiment, the voice coil actuator shared by the first group of measurement modules and the fifth group of measurement modules outputs a pressure of 200 g ± 5 g, and the voice coil actuators corresponding to the remaining measurement modules output a pressure of 100 g ± 5 g. The precisely controllable force ensures that the heat spreader does not deform, and ensures that the thermocouple wires of the thermocouple probe can completely adhere to the heat spreader, ensuring the accuracy of the temperature data collected by the thermocouple probe 1.

[0019] As Figure 1 shown, the temperature measurement module further includes a processing module 6. The processing module 6 includes an MCU unit, a power supply unit, an expansion unit, and a communication unit. The MCU unit includes a processing chip of the STM32F103 series, which is used for data processing and instruction transmission. The power supply unit is used for isolation processing and voltage stabilization of the input voltage. The expansion unit includes an IO expander and input / output terminals, which are used for communication and control between the MCU unit and the heating module and a plurality of the measurement modules. The communication unit is a W5500 network interface chip, and the MCU unit communicates with an external computer through the communication unit.

[0020] As Figure 3As shown, the heating module includes a constant power output unit 3 and a ceramic heating plate 4, the ceramic heating plate 4 is arranged in the fixture to contact and cooperate with the temperature plate, the constant power output unit 3 includes a power supply component, a DAC digital-to-analog converter, an ADC analog-to-digital converter, a PID power control loop, a voltage loop, a current loop and a multiplier; the power supply component is used to convert the input power supply voltage of the power supply unit into the voltage required for the operation of each component; the DAC digital-to-analog converter includes two output channels, one output channel is used to control the voltage comparison sampling of the power supply component, so as to achieve voltage adjustment in the range of +5~+22V, and the other output channel is used to control the power setting of the PID power control loop 0~10W; the ADC analog-to-digital converter is used to convert the voltage signals of the voltage loop and the current loop, and the MCU unit communicates with the ADC analog-to-digital converter to read the voltage U and current I signals of the control loop , so as to read back the calculated power P=UI; the voltage loop includes a rail-to-rail precision instrument amplifier INA826, an RFI filter network, and a rail-to-rail precision operational amplifier OPA2277 in-phase follower, which are used to sample the voltage signal at the load end, realize the four-wire remote voltage signal acquisition, and eliminate the voltage loss error caused by the excessively long line network. This voltage signal will be sent to the multiplier as a constant power feedback signal; the current loop includes a rail-to-rail precision instrument amplifier INA826, an RFI filter network, a rail-to-rail precision operational amplifier OPA2277 in-phase follower, and a current sampling resistor Rsns, which are used to sample the current signal at both ends of the resistor Rsns. The amplified current signal will be sent to the multiplier as a constant power feedback signal; the multiplier selects a four-quadrant, differential high-impedance X / Y input AD633 multiplier to realize a power operator, which is used to configure various analog calculation functions. The PID power control loop includes a 60V, 79A high-power field effect tube IRF1018, a rail-to-rail precision operational amplifier OPA188, and an integral feedback capacitor. The analog voltage output by the DAC sets the voltage and power required for the load drive. At this time, the high-power field effect tube IRF1018 and the ceramic heating plate 4 are connected in series to form a power supply loop. The level signals of the voltage loop and the current loop will be cut into the input end of the multiplier for calculation. The voltage signal after the multiplier calculation and the DAC power level signal set by the MCU unit are compared in the OPA188 operational amplifier, and the output end is cut to synchronously control the gate level of the high-power field effect tube, so that the high-power field effect tube works in the variable resistance area to realize the constant power PID automatic adjustment mode of the load system, so that the ceramic heating plate 4 always works in a constant power state during the heating stage, thereby ensuring the stability of the heating speed.

[0021] The output signal of the multiplier operation power \(P = UI\) is input to the inverting terminal of the rail-to-rail precision operational amplifier OPA188. Through the integrating capacitor connected between the inverting terminal and the output terminal of the rail-to-rail precision operational amplifier OPA188 and the described high-power field-effect transistors, a PID compensation network is constructed to dynamically adjust the difference between the preset power value DAC output of the MCU unit and the measured power, ensuring a constant power output that can be automatically set and adjusted from 0W to 10W ± 0.01W. After successful setting, the power stability reaches 0.33%. The high-power field-effect transistor IRF1018 constructs a power output stage, which cooperates with the instrumentation amplifier INA826 to collect load voltage / current signals in real time. The instantaneous power value is calculated by the multiplier AD633JRZ to form a power closed-loop feedback.

[0022] As Figure 4 shown, the temperature measurement module further includes a collection module 5. A plurality of the T-type thermocouples 11 are electrically connected to the collection module 5. The collection module 5 includes a thermocouple signal ADC converter ADS1220 chip, a thermocouple channel switching switch, an input filter network, and a cold-junction compensation digital temperature sensor. The thermocouple signal ADC converter is used to convert and amplify the electrical signal output by the T-type thermocouple 11. The cold-junction compensation digital temperature sensor TMP117 is soldered on a flexible circuit board, and then the TMP117 sensor is closely attached to the negative terminal (constantan) of the T-type thermocouple 11, thereby collecting the temperature of the negative terminal of the T-type thermocouple 11, accurately determining the thermocouple junction temperature according to the cold-junction temperature, and performing cold-junction compensation, so as to reduce the influence of the cold-junction error caused by the change of the temperature of the measurement board itself and the change of the surrounding environment temperature on the measurement, thereby improving the measurement accuracy and measurement stability. The thermocouple channel switching switch and the input filter network form an eight-channel differential signal input switching, which can realize the measurement of eight thermocouples, and cooperate with the thermocouple signal ADC converter ADS1220 chip to realize synchronous sampling of multiple temperature measurement points, and complete the full-channel data acquisition within 500ms. As Figure 5 shown, \(V\) TC = (V REF × Code) / (2 15 ×Gain) {V TC The voltage is read by the ADC, and Code is the ADC register data} V = V TC + V CJ Add the thermocouple voltage \(V\) TC to the equivalent cold-junction voltage \(V\) CJ measured by the cold-junction compensation digital temperature sensor TMP117 to obtain the actual voltage \(V\). Convert the actual voltage \(V\) to temperature according to the look-up table to determine the accurate thermocouple temperature.

[0023] As Figure 6 shown, the measurement method further includes the following specific steps: Step S1: Before the test, the ceramic heating sheet 4 heats its own temperature to the preheating temperature of 45°C; Step S2: After the temperature of the heating module is stabilized, place the to-be-tested heat spreader in the fixture, and the force adjustment mechanism 2 controls the thermocouple probe 1 to contact the heat spreader with a set force. The first group of measurement modules and the fifth group of measurement modules are arranged in parallel and distributed along the width direction of the heat spreader, and the second group to the fourth group of measurement modules are distributed along the length direction of the heat spreader with the first group of measurement modules as the reference; Step S3: After the contact control is completed, the heating module switches to control with a constant power of 1.5W. At this time, a constant heat load of 1.5W will be applied to the heat spreader to simulate the continuous working state of the chip heat source; Step S4: During the heating stage, set the total sampling duration to 60s. Starting from 0s, synchronously collect the temperature values of the ceramic heating sheet 4, the five groups of thermocouple probes 1, and the ambient temperature every 500ms. During the measurement process, the two thermocouple wires of the thermocouple probe 1 use the heat spreader as an intermediate conductor. The temperature value collected by the ceramic heating sheet 4 is T0, and the temperature values collected by the first group to the fifth group of measurement modules are T1, T2, T3, T4, and T5 in sequence, and the ambient temperature is Ta; Step S5: Calculate the radial temperature difference ΔT1-4 = |T1 - T4|, the local temperature difference ΔT2-3 = |T2 - T3|, ΔT1-2 = |T1 - T2|, the gradient temperature difference ΔT3-4 = |T3 - T4|, ΔT1-5 = |T1 - T5|, and the surface thermal resistance R of the heat spreader CA , in this embodiment, the temperature difference threshold ΔTmax = 2.5°C. Judge the calculation results of the radial temperature difference, local temperature difference, and gradient temperature difference according to the temperature difference threshold. When the calculation results of all temperature differences are lower than the temperature difference threshold and the radial temperature difference ΔT1-4 ≤ 1.8°C, it is judged that the heat conduction performance of the heat spreader is excellent; otherwise, if any temperature difference value exceeds the temperature difference threshold, it is determined that there is a heat accumulation defect; the surface thermal resistance R of the heat spreader CA satisfies: R CA = (T1 - Ta) / P, where P is the heating power of the heating module. In this embodiment, when the surface thermal resistance R of the heat spreader CA is not greater than 18°C / W, it is judged as qualified; Step S6: After the collection is completed, the force adjustment mechanism 2 controls the thermocouple probe 1 to separate from the heat spreader.

[0024] Although the embodiments of the present invention are described in terms of actual solutions, they do not constitute a limitation on the meaning of the present invention. For those skilled in the art, modifications to its implementation solutions according to this specification and combinations with other solutions are obvious.

Claims

1. A precise measurement system for the thermal conductivity of a temperature homogenizing plate, comprising a temperature measurement module, the temperature measurement module comprising a heating module and a plurality of measurement modules, characterized in that: The measuring module comprises a thermocouple probe (1) and a force adjustment mechanism (2) connected to each other. The heating module is arranged in a fixture. The thermocouple probe (1) comprises a T-type thermocouple (11), a positive temperature measuring head (12) and a negative temperature measuring head (13). The positive temperature measuring head (12) and the negative temperature measuring head (13) are independent of each other and are arranged to float relative to the force adjustment mechanism (2). The positive temperature measuring head (12) is provided with a copper wire (14) connected to the positive pole of the T-type thermocouple (11). The negative temperature measuring head (13) is provided with a constantan wire (15) connected to the negative pole of the T-type thermocouple (11). When the copper wire (14) and the constantan wire (15) contact a temperature equalizing plate at the same time, they are short-circuited and form a thermocouple loop.

2. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 1, characterized in that: The plurality of measurement modules are arranged at non-equidistant intervals.

3. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 2, characterized in that: There are five groups of measurement modules in total. The first group of measurement modules and the fifth group of measurement modules are arranged in parallel. The spacing ratio between adjacent modules of the first group of measurement modules, the second group of measurement modules, the third group of measurement modules and the fourth group of measurement modules is 3:4:

3.

4. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 1, characterized in that: The heating module comprises a constant power output unit (3) and a ceramic heating plate (4), wherein the ceramic heating plate (4) is arranged in a fixture and contacts and cooperates with a temperature equalizing plate, and the constant power output unit (3) comprises a power supply component, a DAC digital-to-analog converter, an ADC analog-to-digital converter, a PID power control loop, a voltage loop, a current loop and a multiplier; the power supply component is used to convert the input power supply into the voltage required for the operation of each component; the DAC digital-to-analog converter comprises two output channels, one output channel is used to control the voltage comparison sampling of the power supply component, and the other output channel is used to control the power setting of the PID power control loop. The ADC analog-to-digital converter is used to convert the voltage signals of the voltage loop and the current loop, and the MCU unit communicates with the ADC analog-to-digital converter to read the voltage U and current I signals of the control loop; the voltage loop is used to sample the voltage signal at the load end; the current loop is used to sample the current signal, and the amplified current signal will be used as the constant power feedback signal; the multiplier is a four-quadrant, differential high-impedance X / Y input AD633 multiplier to realize the power operator, and the multiplier is used for calculation; the PID power control loop performs constant power PID adjustment so that the ceramic heating plate (4) always works in a constant power state.

5. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 1, characterized in that: The force adjustment mechanism (2) comprises a voice coil actuator (21) and a pressure sensor, wherein the pressure sensor detects the pressure output by the voice coil actuator (21), and the temperature measurement module further comprises a controller (22) electrically connected to a plurality of the force adjustment mechanisms (2).

6. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 1, characterized in that: The temperature measurement module also includes a collection module (5), and the plurality of T-type thermocouples (11) are electrically connected to the collection module (5), and the collection module (5) includes a thermocouple signal ADC converter, a thermocouple channel switching switch, an input filter network, and a cold-end compensation digital temperature sensor; the thermocouple signal ADC converter is used to convert and amplify the electrical signal output by the T-type thermocouple (11); the cold-end compensation digital temperature sensor is used to collect the temperature of the negative terminal of the T-type thermocouple (11) and perform cold-end compensation; the thermocouple channel switching switch and the input filter network perform channel differential signal input switching.

7. The heat conduction performance precision measurement system of a temperature vapor chamber according to claim 1, characterized in that: The temperature measurement module also includes a processing module (6), the processing module (6) includes an MCU unit, a power supply unit, an expansion unit and a communication unit; the MCU unit is used for data processing and command transmission; the power supply unit is used for isolation processing and voltage stabilization of input voltage; the expansion unit is used for communication and control between the MCU unit and the heating module and a plurality of the measurement modules; the MCU unit communicates with an external computer via the communication unit.

8. A test method, based on the precise measurement system for heat conductivity performance of a vapor chamber as claimed in any one of claims 1 to 7, characterized in that: The measuring method comprises the following specific steps: Step S1: Before testing, the heating module heats itself to a preheating temperature; Step S2, after the temperature of the heating module is stabilized, the temperature homogenizing plate is placed in a fixture, and the force adjustment mechanism (2) controls the thermocouple probes (1) to contact the temperature homogenizing plate with a set force, and each of the thermocouple probes (1) contacts the temperature homogenizing plate at a different position; Step S3: After the contact control is completed, the heating module switches to constant power control to simulate the continuous working state of the chip heat source; Step S4, during the heating process to a thermal steady state, synchronously collecting the temperature values ​​of the heating module, the plurality of thermocouple probes (1) and the ambient temperature at regular intervals, wherein during the measurement process, the two groups of thermocouple wires of the thermocouple probes (1) use a temperature averaging plate as an intermediate conductor; Step S5, calculating the radial temperature difference, local temperature difference, gradient temperature difference and the surface thermal resistance of the heat spreader according to the collected data, and judging the calculation results according to the set temperature difference threshold. If all temperature difference values ​​are lower than the temperature difference threshold, it is judged that the heat spreader has excellent conduction performance; On the contrary, if any temperature difference value exceeds the temperature difference threshold, it is determined that there is a thermal accumulation defect; Step S6: After the acquisition is completed, the force adjustment mechanism (2) controls the thermocouple probe (1) to separate from the temperature homogenizing plate.

Images