Method for predicting service life of molten copper vapor chamber under damage of non-mechanical structure

Abstract

The invention discloses a life prediction method for a molten copper vapor chamber under non-mechanical structure damage, which comprises the following steps: S1, designing and manufacturing the vapor chamber, carrying out aging test and detection, screening out the vapor chamber with an intact mechanical structure but ineffective heat transfer performance, and detecting and determining the weight percentage of copper and oxygen elements on the surface layer of a liquid absorption core of the ineffective vapor chamber; acquiring the distribution and content of copper and oxygen elements on the surface layer of the wick, and establishing a mutual relation between the weight percentage of the oxygen elements on the surface layer of the wick and the aging failure time of the vapor chamber; s2, constructing an aging acceleration model of the vapor chamber, converting aging failure time and service life of the vapor chamber, establishing a mutual relation between the weight percentage of oxygen elements on the surface layer of a liquid absorption core of the vapor chamber and the service life of the vapor chamber, and fitting to obtain a relation curve; and S3, predicting the service life of the vapor chamber according to the weight percentage of the oxygen element on the surface layer of the liquid absorption core of the to-be-measured vapor chamber and the obtained relation curve. The service life of the vapor chamber is quickly predicted according to the weight percentage of oxygen on the surface layer of the wick.

Description

Technical Field

[0001] The present invention belongs to the technical field of life prediction of vapor chambers, and in particular relates to a life prediction method of a copper-water type vapor chamber under non-mechanical structural damage. Background Art

[0002] As electronic products develop towards high integration, multi-function and modularization, the power consumption of chips continues to increase, which inevitably leads to excessively high local temperatures and large temperature differences inside the chip. Due to the differences in the thermal expansion coefficients of the various layers of materials inside the chip, excessively high temperatures or large temperature differences can easily cause chip warping, failure of bonding wires, failure of pins and failure of solder layers, and ultimately lead to product performance degradation and failure. Therefore, in order to ensure or further improve the performance and reliability of electronic products, it is necessary to reasonably dissipate the heat of the internal chips to ensure that the chips are working at the optimal temperature, thereby ensuring product performance and reliability. Traditional heat dissipation methods mainly include natural cooling, forced air cooling and liquid cooling. However, the use of high-power chip packaging has the characteristics of small space and high heat generation. The limitations of traditional heat dissipation methods are prominent and cannot meet actual needs. Therefore, it has become inevitable to seek efficient and reliable heat dissipation methods to solve the heat dissipation problem of high-power chips. With the advancement of technology, the method of heat transfer through gas-liquid phase change based on evaporation and condensation has attracted much attention. Among them, the heat spreader, as a typical gas-liquid phase change heat transfer device, has the basic requirements for solving the heat dissipation problem of high-power chip packaging due to its high thermal conductivity and fast response speed. It has been considered as one of the most effective heat dissipation technologies. However, in order to make the heat spreader truly used for high-power chip packaging heat dissipation, in addition to good temperature equalization performance, the stability of its heat transfer performance and service life under long-term service still need to be clarified. The traditional method relies on long-term high-temperature aging to evaluate the reliability and life of the heat spreader, which is time-consuming, laborious and inefficient, and can no longer meet actual production needs. Therefore, it is particularly important and urgent to find a new and fast method for predicting the life of the heat spreader. Summary of the invention

[0003] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, propose a life prediction method for a copper-water type heat spreader under non-mechanical structural damage, establish a relationship between the weight percentage of oxygen on the surface of the liquid wick and the actual service life of the heat spreader, and obtain a relationship curve between the life of the heat spreader and the oxygen content on the surface of the liquid wick by fitting, so as to realize rapid detection of the life of the heat spreader.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for predicting the life of a copper-water type vapor chamber under non-mechanical structural damage comprises the following steps: S1. Design and manufacture a copper-water type vapor chamber, conduct aging tests and inspections, screen out vapor chamber samples with intact mechanical structures but failed heat transfer performance, detect and determine the weight percentage of copper-oxygen elements on the surface of the failed vapor chamber wick, obtain the distribution and content of copper-oxygen elements on the surface of the wick, and establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the aging failure time of the vapor chamber; S2. Construct an accelerated aging model for the vapor chamber, convert the aging failure time of the vapor chamber into an equivalent service life, establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber, and obtain a relationship curve by fitting; S3. Detect the weight percentage of oxygen elements on the surface of the vapor chamber wick to be tested, and predict the service life of the vapor chamber according to the relationship curve between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber.

[0005] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention constructs a life prediction method for a copper-water type heat spreader under non-mechanical structural damage, establishes a relationship curve between the weight percentage of oxygen elements on the surface of the liquid wick and the actual service life of the heat spreader, and can calculate the life of the heat spreader according to the weight percentage of oxygen elements on the surface of the liquid wick of the heat spreader, thereby realizing a rapid prediction of the life of the heat spreader; compared with the existing methods, the present invention predicts the life of the heat spreader according to the weight percentage of oxygen elements on the surface of the liquid wick, and can realize a rapid detection of the life of the heat spreader without a time-consuming aging experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a flow chart of the method of the present invention; Figure 2 1. It is a schematic diagram of a device for testing heat transfer performance of a vapor chamber; Figure 3 is a schematic diagram of an aging test of an embodiment; Figure 4 is a schematic diagram of appearance inspection results in the embodiment; Figure 5 is a schematic diagram of the results of the vapor chamber leakage detection in the embodiment; Figure 6 Schematic diagram of the internal structure damage detection result of the heat spreader in the embodiment; Figure 7 Schematic diagram of the test result of the pore structure change of the liquid absorbent core in the embodiment; Figure 8 is a graph showing the relationship between the weight percentage of oxygen elements on the surface of the liquid wick and the aging failure time of the vapor chamber in the embodiment; Fig. 9 1. It is a schematic diagram of the activation energy calculation method and results of the embodiment; Fig.103 is a curve diagram showing the relationship between the service life of the vapor chamber and the weight percentage of oxygen element on the surface of the liquid wick in the embodiment. DETAILED DESCRIPTION

[0007] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0008] Example like Figure 1 As shown, the present invention provides a life prediction method for a copper-water type heat sink under non-mechanical structural damage, comprising the following steps: S1. Design and manufacture copper-water type vapor chambers, conduct aging tests and inspections, select vapor chamber samples with intact mechanical structures but failed heat transfer performance, detect and determine the weight percentage of copper-oxygen elements on the surface of the failed vapor chamber wick, obtain the distribution and content of copper-oxygen elements on the surface of the wick, and establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the aging failure time of the vapor chamber; specifically including: S11. Based on the general principles of vapor chamber design, a certain amount of copper-water vapor chambers are designed and manufactured. In this embodiment, specifically: Based on the general design principles of the vapor chamber, oxygen-free copper is used as the raw material to obtain the upper and lower shell plates of the vapor chamber by stamping; The evaporation end liquid absorption core adopts a trunk structure made of sintered copper powder, and the condensation end liquid absorption core adopts a wire mesh structure, which is connected by a smooth copper column and a powder ring made of sintered copper powder in the middle; The vacuum removal time is 300s, the liquid injection volume is 85% of the saturated water volume of the liquid wick, and the heat transfer power is 600W. The temperature uniformity is good, and it can withstand high temperatures of 200℃ and will not cause structural failure in hot and cold shocks. It is a high-performance copper water type heat sink.

[0009] S12, build a heat transfer performance test device for the vapor chamber, test the heat transfer performance of the manufactured vapor chamber and select the vapor chamber samples with qualified heat transfer performance; in this embodiment, Figure 2 As shown, the heat transfer performance test device of the vapor chamber specifically includes: Program-controlled power supply, NI temperature acquisition card, constant temperature water tank, rotor flowmeter, heating rod, heating copper block, water cooling plate, thermocouple, motion controller and industrial computer; The program-controlled power supply is connected to the heating copper block through the heating rod to adjust the heating power; The evaporation end of the vapor chamber contacts the heating copper block, and the condensation end contacts the water cooling plate. The heating copper block is used to heat the vapor chamber; The built-in working medium flow channel of the water-cooled plate is connected to the constant temperature water tank and rotor flowmeter. By setting the cooling water temperature and flow, the heat transferred by the heat spreader is taken away to achieve the purpose of heat dissipation. Five thermocouples are arranged at the evaporation end and condensation end of the heat spreader to obtain the temperature of the upper and lower surfaces of the heat spreader. A thermocouple is welded in the slot of the heating copper block to obtain the temperature of the heat source. A thermocouple is arranged at the inlet and outlet of the water cooling plate to obtain the temperature of the inlet and outlet. The accuracy of the thermocouple is set to ±0.5℃. One end of the NI temperature acquisition card is connected to the thermocouple, and the other end is connected to the industrial computer. The temperature data obtained by the thermocouple is collected, stored, and recorded, and the data is transmitted to the industrial computer. The motion controller is connected to the industrial computer and is responsible for the operation of the entire test device.

[0010] In this embodiment, the heat transfer performance of the manufactured vapor chamber is tested and vapor chamber samples with qualified heat transfer performance are screened out, specifically: The heat transfer performance test device of the vapor chamber was used to test the heat transfer performance of the vapor chamber at different heating powers, and the vapor chamber with qualified heat transfer performance was selected based on three parameter indicators: heat source temperature, center temperature difference between the vapor chamber evaporation surface and the condensation surface, and center temperature difference between the evaporation surface and the surrounding temperature. During the test, in order to eliminate the influence of natural convection heat transfer on the test results, heat insulation treatment was performed, the test water temperature was set to 40°C, and the water flow rate was set to 11L / min.

[0011] S13, placing the selected heat spreaders with qualified heat transfer performance in a high-temperature aging box for aging test, and selecting the failed heat spreaders according to the failure judgment conditions; in this embodiment, Figure 3 As shown, specifically: The selected heat spreaders with qualified heat transfer performance were numbered, and 10% of the samples were selected as standard samples, the remaining 75% of the samples were used as test samples, and the remaining 15% of the samples were kept separately for subsequent experiments; The standard samples are packaged and stored, and the test samples are placed in a 150℃ constant temperature test chamber for aging test; Take out all the test samples every 48 hours, retest their heat transfer performance using a vapor chamber heat transfer performance test device, and compare and analyze the retest results with the initial test results; The failure judgment standard is that the heat source temperature of the vapor chamber degrades by more than 2°C under 600W. The vapor chamber samples with qualified re-tested heat transfer performance are put back into the constant temperature box for aging test. The vapor chambers with unqualified re-tested heat transfer performance are failed vapor chambers, and the aging test is no longer continued. The aging time is recorded and the failed vapor chamber samples are collected and stored for subsequent failure analysis.

[0012] S14, testing and analyzing the failed vapor chambers, and selecting vapor chamber samples with intact mechanical structures but failed heat transfer performance; in this embodiment, specifically: Formulate a mechanical structure inspection process for failed vapor chambers, which includes appearance inspection, vapor chamber leakage inspection, vapor chamber internal structure damage inspection, and wick pore structure change inspection. Finally, comprehensively analyze the inspection results to select vapor chamber samples with intact mechanical structures but failed heat transfer performance. The appearance inspection is as follows: The KEYENCE VHX-7000 optical microscope and VR3050 flatness measuring instrument were used to test the appearance and flatness of the failed vapor chamber to determine whether the appearance and structure of the failed vapor chamber were intact. Figure 4 The test results of this embodiment are shown.

[0013] The specific test of vapor chamber leakage is as follows: The helium leak detection device is used to detect the heat plate leakage. The basic principle is: under the action of external pressure, when cracks or invisible holes appear in the heat plate, helium will quickly erode into the heat plate from the cracks or holes, destroying the vacuum environment of the inner cavity, causing the performance of the heat plate to drop rapidly, and the temperature of the heat source to rise rapidly under the same conditions. Otherwise, it means that the heat plate is intact and there is no leakage; Figure 5 The test results of this embodiment are shown.

[0014] The specific damage detection of the internal structure of the heat spreader is as follows: Use X-Ray equipment to detect the damage of the internal structure of the vapor chamber, and judge the integrity of the internal structure of the vapor chamber by observing the X-ray image; Figure 6 The test results of this embodiment are shown.

[0015] The specific detection of the change in the pore structure of the liquid wick is as follows: The mercury intrusion method is used to detect the changes in the pore structure of the wick. By comparing the changes in the pore structure characteristics of the normal and failed vapor chamber wicks, it is determined whether the pore structure of the wick is damaged. Figure 7 The test results of this embodiment are shown.

[0016] S15. Use SEM-EDS to detect the weight percentage of copper oxygen elements on the surface of the failed vapor chamber wick, obtain the distribution and content of copper oxygen elements on the surface of the wick, and establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the aging failure time of the vapor chamber; in this embodiment, specifically: Under nitrogen protection, the selected heat spreaders with intact mechanical structures but failed heat transfer performance were cut to make SEM-EDS test samples with a sample size of 10mm×10mm×1mm. To avoid the influence of the environment on the test results, the test samples were stored in vacuum. The weight percentage of copper and oxygen elements on the surface of the test sample was tested by SEM-EDS to obtain the distribution and content of copper and oxygen elements on the surface of the wick. The weight percentage of oxygen elements on the surface of the wick is calculated, and then the relationship between the weight percentage of oxygen elements on the surface of the wick and the aging failure time of the corresponding vapor chamber is established, such as Figure 8 shown.

[0017] S2. Construct an accelerated aging model for the vapor chamber, convert the aging failure time of the vapor chamber into an equivalent service life, establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber, and obtain a relationship curve by fitting; In this embodiment, a vapor chamber aging acceleration model is constructed to convert the vapor chamber aging failure time to the service life equivalently, specifically: The remaining 15% of the vapor chamber samples with qualified heat transfer performance were evenly divided into 3 groups, and the 3 groups of vapor chamber samples were placed at three temperatures, T1, T2, and T3, for aging tests at the same time. The failure criterion was that the vapor chamber heat source temperature degraded by more than 2°C at 600W, and the average aging failure time t1, t2, and t3 of the vapor chamber samples at T1, T2, and T3 were calculated; Take lnt as the ordinate and 1 / T as the abscissa to form three coordinate points (1 / T1, lnt1), (1 / T2, lnt2), (1 / T3, lnt3), draw in the same coordinate system, and calculate the equation of the line; Take the logarithm of both sides of the Arrhenius formula and transform it to get the linear equation between lnt and 1 / T, where the slope of the equation is E a / K, K is a constant; Fig. 9 As shown, the aging failure activation energy E of the copper-water type heat sink is calculated based on the slope of the actual straight line equation. a is 0.84ev; the transformed Arrhenius formula is: ; Where t is the aging failure time; E a is the energy consumed for the precipitation of faults, i.e., the activation energy, which is 0.84 eV; K is the Boltzmann constant, which is 8.617385×10 -5 ; T is the aging temperature, the unit is K (Kelvin); A is a constant parameter; Construct a vapor chamber aging acceleration model, specifically: Taking the exponents on both sides of the transformed Arrhenius formula, we get: ; When the actual use temperature of the heat plate is T u , aging temperature is T t When T u The life of the heat sink at temperature is t u , T t The life of the heat sink at temperature is t t, substituting into the above formula we get: ; ; Dividing the above two equations, we get: ; in, The value of is the aging acceleration factor, represented by AF, and the aging acceleration model of the heat spreader is obtained, which is expressed as: ; Among them, T u is the actual operating temperature of the heat sink, in K (Kelvin), T t is the temperature value of the heat sink aging, in K (Kelvin); The vapor chamber aging acceleration model is used to convert the vapor chamber aging failure time to its actual service life, specifically: The aging acceleration factor AF in the vapor chamber aging acceleration model is used Expressed in detail, we get: ; Among them, t u is the actual service life of the vapor chamber, t t is the aging failure time of the vapor chamber; E a , T u , T t ,t t Substitute into the formula and calculate the actual life of the heat spreader t u , to achieve the mutual conversion between the aging failure time of the heat spreader and its actual service life.

[0018] In this embodiment, the relationship between the weight percentage of oxygen element on the surface of the vapor chamber wick and the service life of the vapor chamber is established and a relationship curve is obtained by fitting, specifically: The actual service life of the vapor chamber corresponds to the weight percentage of oxygen elements on the surface of the wick, and a scatter plot is drawn with the weight percentage of oxygen elements on the surface of the wick as the horizontal axis and the actual service life of the vapor chamber as the vertical axis; The data were statistically analyzed and fitted to obtain the relationship curve and equation between the service life of the vapor chamber and the weight percentage of oxygen element on the surface of the wick, such as Fig.10 shown.

[0019] S3. Detect the weight percentage of oxygen elements on the surface of the vapor chamber wick to be tested, and predict the service life of the vapor chamber according to the relationship curve between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber.

[0020] like Fig.10As shown in the figure, the curve results show that the actual service life of the copper-water type vapor chamber is a quadratic function of the weight percentage of oxygen elements on the surface of the liquid wick. When the weight percentage of oxygen elements on the surface of the liquid wick of the vapor chamber is about 0.5%, the vapor chamber can generally work normally for 15 years or more without degradation without external force damage. When the weight percentage of oxygen elements on the surface of the liquid wick is between 1% and 2%, the vapor chamber generally works for about 10 years.

[0021] It should also be noted that in this specification, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0022] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting the life of a copper-water type heat sink under non-mechanical structural damage, characterized in that: The following steps are involved: S1. Design and manufacture a copper-water type vapor chamber, conduct aging tests and inspections, screen out vapor chamber samples with intact mechanical structures but failed heat transfer performance, detect and determine the weight percentage of copper-oxygen elements on the surface of the failed vapor chamber wick, obtain the distribution and content of copper-oxygen elements on the surface of the wick, and establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the aging failure time of the vapor chamber; S2. Construct an accelerated aging model for the vapor chamber, convert the aging failure time of the vapor chamber into an equivalent service life, establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber, and obtain a relationship curve by fitting; S3. Detect the weight percentage of oxygen elements on the surface of the vapor chamber wick to be tested, and predict the service life of the vapor chamber according to the relationship curve between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the service life of the vapor chamber.

2. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 1 is characterized in that: Step S1 specifically includes: S11. Design and manufacture a preset number of copper-water vapor chambers based on the general design principles of vapor chambers; S12, building a heat transfer performance test device for the vapor chamber, testing the heat transfer performance of the manufactured vapor chambers, and selecting vapor chamber samples with qualified heat transfer performance; S13, placing the selected vapor chambers with qualified heat transfer performance in a high-temperature aging box for aging test, and selecting the failed vapor chambers according to the failure judgment conditions; S14. Detect and analyze failed vapor chambers, and select vapor chamber samples with intact mechanical structures but failed heat transfer performance; S15. Use SEM-EDS to detect the weight percentage of copper and oxygen elements on the surface of the failed vapor chamber wick, obtain the distribution and content of copper and oxygen elements on the surface of the wick, and establish the relationship between the weight percentage of oxygen elements on the surface of the vapor chamber wick and the aging failure time of the vapor chamber.

3. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 2 is characterized in that: Step S11 is specifically as follows: Based on the general design principles of the vapor chamber, oxygen-free copper is used as the raw material to obtain the upper and lower shell plates of the vapor chamber by stamping; The evaporation end liquid absorption core adopts a trunk structure formed by sintering copper powder, and the condensation end liquid absorption core adopts a wire mesh structure, which is connected in the middle by a smooth copper column and a powder ring sintered by copper powder to obtain a copper water type heat sink.

4. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 3 is characterized in that: In step S12, the heat transfer performance testing device of the vapor chamber specifically includes: Programmable power supply, NI temperature acquisition card, constant temperature water tank, rotor flowmeter, heating rod, heating copper block, water cooling plate, thermocouple, motion controller and industrial computer; The program-controlled power supply is connected to the heating copper block through the heating rod to adjust the heating power; The evaporation end of the vapor chamber contacts the heating copper block, and the condensation end contacts the water cooling plate. The heating copper block is used to heat the vapor chamber; The water-cooling plate has a built-in working fluid flow channel connected to a constant temperature water tank and a rotor flow meter for heat dissipation; Five thermocouples are arranged at the evaporation end and condensation end of the heat spreader to obtain the temperature of the upper and lower surfaces of the heat spreader; a thermocouple is welded in the slot of the heating copper block to obtain the temperature of the heat source; a thermocouple is arranged at the inlet and outlet of the water cooling plate to obtain the temperature of the inlet and outlet; One end of the NI temperature acquisition card is connected to the thermocouple, and the other end is connected to the industrial computer. The temperature data obtained by the thermocouple is collected, stored, and recorded, and the data is transmitted to the industrial computer. The motion controller is connected to the industrial computer and is responsible for the operation of the entire test device.

5. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 4 is characterized in that: In step S12, the heat transfer performance of the manufactured vapor chamber is tested and vapor chamber samples with qualified heat transfer performance are screened out, specifically: The heat transfer performance testing device of the vapor chamber was used to test the heat transfer performance of the vapor chamber under different heating powers. The vapor chamber with qualified heat transfer performance was selected based on three parameter indicators: heat source temperature, center temperature difference between the evaporation surface and the condensation surface of the vapor chamber, and difference between the center temperature of the evaporation surface and the surrounding temperature.

6. The method for predicting the life of a copper-water vapor chamber under non-mechanical structural damage according to claim 5, characterized in that: Step S13 is specifically as follows: The selected heat spreaders with qualified heat transfer performance were numbered, and 10% of the samples were selected as standard samples, the remaining 75% of the samples were used as test samples, and the remaining 15% of the samples were kept separately for subsequent experiments; The standard samples are packaged and stored, and the test samples are placed in a 150℃ constant temperature test chamber for aging test; Take out all the test samples every 48 hours, retest their heat transfer performance using a vapor chamber heat transfer performance test device, and compare and analyze the retest results with the initial test results; The failure judgment standard is that the heat source temperature of the vapor chamber degrades by more than 2°C under 600W. The vapor chamber samples with qualified re-tested heat transfer performance are put back into the constant temperature box for aging test. The vapor chambers with unqualified re-tested heat transfer performance are failed vapor chambers, and the aging test is no longer continued. The aging time is recorded and the failed vapor chamber samples are collected and stored for subsequent analysis.

7. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 2 is characterized in that: Step S14 is specifically as follows: Formulate a mechanical structure inspection process for failed vapor chambers, which includes appearance inspection, vapor chamber leakage inspection, vapor chamber internal structure damage inspection, and wick pore structure change inspection. Finally, based on the comprehensive inspection results, vapor chamber samples with intact mechanical structures but failed heat transfer performance are selected. The appearance inspection is as follows: Use an optical microscope and a flatness measuring instrument to test the appearance and flatness of the failed vapor chamber to determine whether the appearance and structure of the failed vapor chamber are intact; The specific test of vapor chamber leakage is as follows: Use helium leak detection device to detect heat plate leaks; The specific damage detection of the internal structure of the heat spreader is as follows: Use X-Ray equipment to detect the internal structure damage of the vapor chamber, and judge the integrity of the internal structure of the vapor chamber by observing the X-ray image; The specific detection of the change in the pore structure of the liquid wick is as follows: The mercury intrusion method is used to detect the changes in the pore structure of the wick. By comparing the changes in the pore structure characteristics of the wick of the normal and failed vapor chamber, it is determined whether the pore structure of the wick is damaged.

8. The method for predicting the life of a copper-water vapor chamber under non-mechanical structural damage according to claim 2, characterized in that: Step S15 is specifically as follows: Under a nitrogen protection environment, the selected heat spreaders with intact mechanical structures but failed heat transfer performance were cut to produce SEM-EDS test samples; The weight percentage of copper and oxygen elements on the surface of the test sample was tested by SEM-EDS to obtain the distribution and content of copper and oxygen elements on the surface of the wick. The weight percentage of oxygen element on the surface of the wick is counted, and then the relationship between the weight percentage of oxygen element on the surface of the wick and the aging failure time of the corresponding vapor chamber is established.

9. The life prediction method of the copper-water type heat sink under non-mechanical structural damage according to claim 6, characterized in that: In step S2, a vapor chamber aging acceleration model is constructed to convert the vapor chamber aging failure time to the service life equivalently, specifically: The remaining 15% of the vapor chamber samples with qualified heat transfer performance were evenly divided into 3 groups, and the 3 groups of vapor chamber samples were placed at three temperatures, T1, T2, and T3, for aging tests at the same time. The failure criterion was that the vapor chamber heat source temperature degraded by more than 2°C at 600W, and the average aging failure time t1, t2, and t3 of the vapor chamber samples at T1, T2, and T3 were calculated; Take lnt as the ordinate and 1 / T as the abscissa to form three coordinate points (1 / T1, lnt1), (1 / T2, lnt2), (1 / T3, lnt3), draw in the same coordinate system, and calculate the equation of the line; Take the logarithm of both sides of the Arrhenius formula and transform it to get the linear equation between lnt and 1 / T, where the slope of the equation is E a / K, K is a constant; the aging failure activation energy E of the copper-water type heat sink is calculated based on the slope of the actual linear equation a is 0.84ev; the transformed Arrhenius formula is: ； Where t is the aging failure time; E a is the energy consumed for the precipitation of faults, i.e., the activation energy, which is 0.84 eV; K is the Boltzmann constant, which is 8.617385×10 -5 ; T is the aging temperature; A is a constant parameter; Construct a vapor chamber aging acceleration model, specifically: Taking the exponents on both sides of the transformed Arrhenius formula, we get: ； When the actual use temperature of the heat plate is T u , aging temperature is T t When T u The life of the heat sink at temperature is t u , T t The life of the heat sink at temperature is t t , substituting into the above formula we get: ； ； Dividing the above two equations, we get: ； in, The value of is the aging acceleration factor, represented by AF, and the aging acceleration model of the heat spreader is obtained, which is expressed as: ； Among them, T u is the actual operating temperature of the vapor chamber, T t is the temperature value of the vapor chamber aging; The vapor chamber aging acceleration model is used to convert the vapor chamber aging failure time to its actual service life. The specific calculation method is: The aging acceleration factor AF in the vapor chamber aging acceleration model is used Expression, we get: ； Among them, t u is the actual service life of the vapor chamber, t t is the aging failure time of the vapor chamber; E a , T u , T t ,t t Substitute into the formula and calculate the actual service life of the heat spreader t u , to achieve the mutual conversion between the aging failure time of the heat spreader and its actual service life.

10. The method for predicting the life of a copper-water vapor chamber under non-mechanical structural damage according to claim 1, characterized in that: In step S2, the relationship between the weight percentage of oxygen element on the surface of the vapor chamber wick and the service life of the vapor chamber is established and a relationship curve is obtained by fitting, specifically: The actual service life of the vapor chamber corresponds to the weight percentage of oxygen on the surface of the wick, and a scatter plot is drawn with the weight percentage of oxygen on the surface of the wick as the horizontal axis and the actual service life of the vapor chamber as the vertical axis; The data were statistically analyzed and fitted to obtain the relationship curve and equation between the life of the vapor chamber and the weight percentage of oxygen element on the surface of the wick.

Images