CN108387601B - Device and method for measuring thermal resistance of high-heat-conducting-piece-metal heat sink interface - Google Patents
Device and method for measuring thermal resistance of high-heat-conducting-piece-metal heat sink interface Download PDFInfo
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- CN108387601B CN108387601B CN201810009990.3A CN201810009990A CN108387601B CN 108387601 B CN108387601 B CN 108387601B CN 201810009990 A CN201810009990 A CN 201810009990A CN 108387601 B CN108387601 B CN 108387601B
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- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
Abstract
The invention provides a device and a method for measuring thermal resistance of a high-thermal-conductivity sheet-metal heat sink interface, and belongs to the technical field of packaging measurement. The device comprises an adjustable direct current power supply, a heat collection system, a heat collection body, a heat insulation material and a temperature data acquisition system, wherein the adjustable direct current power supply is connected with the heat collection system, the temperature data acquisition system acquires data of the heat collection system, the heat collection body is arranged in the heat collection system, and the heat insulation material is wrapped around the heat collection body. The adjustable direct current power supply heats the heat collecting body; three temperature measuring points are equidistantly distributed on a heat transfer channel of the heat collector, and a high-precision thermocouple is arranged for temperature measurement; the surface of a high heat conducting sheet of a sample to be measured is in direct contact with the working surface of a heat collecting body, and one side of the metal heat sink surface is provided with another high-precision thermocouple for temperature collection. After the temperature stabilized, the temperature at each point was recorded as the calculated temperature. The device has simple and reliable overall structure and low construction cost, and can be used for guiding the low-thermal resistance connection design of the high-thermal-conductivity material and the metal heat sink material.
Description
Technical Field
The invention relates to the technical field of packaging measurement, in particular to a device and a method for measuring thermal resistance of a high-thermal-conductivity sheet-metal heat sink interface.
Background
The trend toward miniaturization of electronic devices and the increasing density of single-chip electronic components has placed modern electronic devices on increasingly higher performance requirements for thermal management materials. Diamond has extremely high hardness, low coefficient of thermal expansion and high thermal conductivity (up to 2200 W.m)-1k-1) The method plays a significant role in the thermal design of high-power electronic chips. When the CVD diamond sheet is used as a heat sink material for high-power electronic devices, the CVD diamond sheet is connected to a power electronic device and also needs to be connected to an external heat dissipation system (usually a metal heat sink system) (by gluing or welding), so that the diamond sheet-metal heat sink connection interface is a key link for determining the heat conductivity of the whole system. Currently, the understanding of the heat conduction mechanism at the diamond sheet-metal interface is still inadequate. On the other hand, the method and the device for testing the interface thermal resistance are relatively lacked, and the reality is difficult to obtain at presentAnd the credible measurement data can limit the further application and popularization of the ultra-high heat conduction material such as the diamond sheet. In addition, from the aspect of interface design, how to optimize the connection mode of the diamond high-thermal-conductivity sheet and the metal also needs to be established on the basis of effectively collecting interface thermal resistance data. Therefore, based on the above situation, a set of measurement method and apparatus that is specific and effective is needed to achieve the above objectives.
As for the heat transfer interface thermal resistance test method, there are generally a steady state method and a transient state method. The former is to keep a certain temperature difference on two contact samples, measure the temperature value of each longitudinal point of the two samples, and extrapolate the temperature value to a contact interface according to the Fourier law so as to obtain the interface temperature difference. The method is relatively simple in test and easy to operate, but the measurement time is long, the method is not easy to realize for small flake samples, and the method is suitable for samples with larger sizes. The Chinese invention patent (publication No. CN104359942A) adopts the steady-state measurement mode; the latter adopts means such as thermal imaging, laser photo-thermal, laser scintillation and the like, carries out high-speed infrared two-dimensional temperature recording on the interfaces of two contacted samples through an infrared high-speed camera system, and obtains interface thermal resistance data through one-dimensional inverse problem solving. The method is non-contact, quick in response and high in resolution, but has extremely high requirements on a measuring device and an algorithm, and the measuring precision is also to be improved. The chinese patent (CN104849308A) adopts a transient measurement method. Although the two Chinese patents are interface measurement methods, the interface measurement methods are only suitable for large-size components and cannot be used for measuring the connection thermal resistance of the thin heat-conducting sheet; the latter is mainly studied aiming at the interface structure, and a special thermal resistance test platform is adopted.
In terms of the current technology, there is no simple and effective measurement method and device for measuring the thermal resistance of the packaging interface of the high-thermal-conductivity sheet, which poses certain obstacles to the application research of the diamond high-thermal-conductivity sheet and other heat sinks. Therefore, a set of relatively simple, effective and high-precision thermal resistance measurement method and device for the interface between the heat-conducting fin and the metal heat sink needs to be explored.
Disclosure of Invention
The invention aims to provide a device and a method for measuring thermal resistance of a high-thermal-conductive-sheet-metal heat sink interface, which are mainly used for carrying out thermal resistance test analysis on a packaging interface of a high-thermal-conductive-sheet material, particularly a CVD diamond material, and a metal heat sink material.
The device comprises an adjustable direct current power supply, a heat collection system, a heat collection body, a heat insulation material and a temperature data acquisition system, wherein the adjustable direct current power supply is connected with the heat collection system, the temperature data acquisition system acquires data of the heat collection system, the heat collection body is arranged in the heat collection system, and the heat insulation material is wrapped around the heat collection body.
The heat collecting body is sealed in the heat collecting system shell, and the middle of the heat collecting system shell is filled with heat-insulating materials.
Three temperature measuring points are equidistantly distributed on the heat collecting body, and a high-precision thermocouple is arranged on each temperature measuring point for temperature measurement.
The heat collector comprises a heating body, a heat transfer material, a high heat-conducting fin and a connecting layer, wherein the heat transfer material is arranged around the heating body, and the high heat-conducting fin is arranged between the heat transfer material and the connecting layer.
The heating body adopts parallel processing, and is connected to the output end of the power supply through a lead after being connected in parallel; the heating body is sealed by the cover plate and fixed in the groove on the lower surface of the heat collector.
The method for measuring by adopting the measuring device comprises the following specific steps:
the upper surface of the heat collector is a working surface, the surface of the high heat conducting sheet-metal heat sink sample to be measured is in direct contact with the working surface of the heat collector, three temperature measuring points on the heat collector are provided with high-precision thermocouples for temperature measurement (T1, T2 and T3), and the temperature measurement is recorded by a temperature data acquisition system; another high-precision thermocouple (T4) is also arranged on one side of the metal heat sink surface of the high-thermal-conductive sheet-metal heat sink sample to be measured for temperature acquisition; during testing, firstly, the room temperature is kept stable, and all temperature measuring points are at the same temperature before heating; after heating, the temperature of each point gradually rises, and after the temperature of each temperature point is kept stable, the temperature of each point is recorded as the calculated temperature.
The technical scheme of the invention has the following beneficial effects:
1. the test method and the test device are very simple, the assembly test can be completed in a common laboratory, and a very expensive and professional test detection instrument is not needed;
2. the input power is regulated in an electrodeless way, the test range is wide, and the measurement of the interface thermal resistance of a device with low heat flow density (watt level) to high heat flow density (hectowatt level) is covered;
3. the object to be measured has no strict requirement and can cover materials with low thermal resistance to materials with high thermal resistance; in addition, the external dimension can be adjusted according to the size of the test piece;
4. the operation is simple, the input power is determined only by adjusting the current, and then the temperature value is obtained through the paperless recording system, so that the thermal resistance value of the connecting interface can be simply calculated through a formula;
5. besides quantitative calculation of the interface thermal resistance R, qualitative analysis can be carried out on the interface heat transfer effect, namely different temperature rise curves can be obtained by inputting fixed power W in the test process, recording the change value of T4 along with time, and drawing time and temperature respectively by using an abscissa and an ordinate, so that the thermal resistance of different connecting interfaces can be qualitatively analyzed.
Drawings
FIG. 1 is a schematic structural diagram of a high thermal conductive sheet-metal heat sink interface thermal resistance measuring device according to the present invention;
FIG. 2 is a schematic view of the structure of a heat collector in the thermal resistance measuring device of the interface between a high thermal conductive sheet and a metal heat sink according to the present invention;
FIG. 3 shows an input power density of 8W/cm in an embodiment of the present invention2Temperature rise curves obtained for two different interface connection systems under the conditions.
Wherein: 1-an adjustable dc power supply; 2-a heat collecting system; 3-heat collecting body; 4-heat preservation and insulation material; 5-a temperature data acquisition system; 6-heating body; 7-a heat transfer material; 8-high thermal conductive sheet; 9-a tie layer; 10-high heat-conducting strip to be tested-metal heat sink sample.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
The invention provides a device and a method for measuring thermal resistance of a high-heat-conducting-piece-metal heat sink interface.
As shown in fig. 1, the measuring device includes an adjustable dc power supply 1, a heat collecting system 2, a heat collecting body 3, a thermal insulation material 4 and a temperature data collecting system 5, wherein the adjustable dc power supply 1 is connected to the heat collecting system 2, the temperature data collecting system 5 collects data of the heat collecting system 2, the heat collecting body 3 is disposed in the heat collecting system 2, and the thermal insulation material 4 is wrapped around the heat collecting body 3. The adjustable direct current power supply 1 can determine the input power W by adjusting the input current value and the voltage value, and the input power can be approximate to the heating power and the heating power W generated on the heat collector;
wherein, the heat collector 3 is sealed in the shell of the heat collecting system 2, and the middle of the shell of the heat collecting system 2 is filled with a heat-insulating material 4, thereby ensuring that the heat generated by the heating body is completely conducted to the upper surface, namely the working surface, from the bottom. Three temperature measuring points (T1, T2 and T3) are equidistantly distributed on the heat collector 3, and each temperature measuring point is respectively provided with a high-precision thermocouple for temperature measurement.
As shown in fig. 2, the heat collector 3 comprises a heating body 6, a heat transfer material 7, a high thermal conductive sheet 8 and a connection layer 9, wherein the heat transfer material 7 is arranged around the heating body 6, and the high thermal conductive sheet 8 is arranged between the heat transfer material 7 and the connection layer 9.
The heating body 6 adopts parallel processing, and is connected to the output end of the power supply through a lead after being connected in parallel; the heating body 6 is sealed by a cover plate and fixed in a groove on the lower surface of the heat collecting body 3.
The method for measuring by adopting the measuring device is roughly as follows: the upper surface of the heat collector 3 is a working surface, and the surface temperature (T0) of the heat collector is obtained by linear fitting of the change rules of T1, T2 and T3; directly contacting the surface of the high heat conducting sheet-metal heat sink sample 10 to be measured with the working surface of the heat collector 3, wherein the surface temperature of the high heat conducting sheet is also considered as T0, and three temperature measuring points on the heat collector 3 are provided with high-precision thermocouples for temperature measurement and are recorded by the temperature data acquisition system 5; arranging another high-precision thermocouple on one side of the metal heat sink surface of the high-thermal-conductivity sheet-metal heat sink sample 10 to be measured, and collecting the temperature (T4); during testing, the room temperature is kept stable, and each temperature measuring point is at the same temperature before heating. After heating, the temperature of each point gradually rises, and when the heating time is long enough, the temperature of each temperature point keeps stable, and at the moment, the temperature of each point is recorded as the calculated temperature.
The temperature difference between the upper surface and the lower surface of the high heat-conducting fin-metal heat sink sample is as follows:
ΔT＝T0-T4
according to the corresponding input power W, the overall thermal resistance R of the weldment is as follows:
r is W/DeltaT (unit W/. degree. C.)
In order to ensure that the heat generated by each heating body is the same, all the heating bodies are processed in parallel, all the wire joints are pasted and coated by insulating tapes, and the heating bodies are connected to the power output end through one wire after being connected in parallel. The heating body is sealed by the cover plate and is uniformly and orderly fixed in the groove on the lower surface of the heat collector. The thermocouple penetrates through the heat insulation material and is finally inserted into the heat transfer channel of the heat collection body; in the whole test process, except the metal heat sink surface of the sample to be tested is exposed outside, the rest of the heat collecting body, the high heat conducting sheet and the like are coated by the heat insulating material.
In the specific implementation process, the input voltage of the adjustable direct-current power supply 1 is 220V alternating current, the output range is 0-10A and is continuously adjustable, and the maximum value of the output power is 500W; the heat collecting system 2 is a closed container, generally adopt the better polymer material of heat insulating ability to make, the overall dimension is 200 x 200mm, the height is 150mm, the side has three apertures according to the thermocouple distribution position in advance, in order to facilitate the thermocouple lead wire, the invention chooses the thermocouple to be T-type thermocouple, the precision is high, respond to fast, the diameter of the probe is about 1 mm; the heat collector 3 has a large bottom area, rapidly decreases upward, and finally has a heat transfer passage with a length of about 10 mm. Three small holes with the diameter of 1mm and the depth of about 2mm are equidistantly distributed on the side surface of the heat transfer channel, so that the thermocouples T1, T2 and T3 can be inserted and fixed conveniently. The heat-insulating material 4 is generally made of an aluminum silicate cotton material and has the characteristics of high use temperature and good heat-insulating effect; the temperature data acquisition system 5 adopts a four-channel commercial data recorder, and can acquire and output thermocouple temperature data of four channels simultaneously.
The core component of the device is a heat collecting body 3, and the structural schematic diagram is shown in fig. 2. The main component of the heat collector is a heat transfer material 7, and here, a red copper material with very high heat conductivity is generally selected. The lower part of the red copper heat conductor is provided with a groove, and the ceramic heating plate is sealed in the groove through a cover plate. The upper surface of the copper heat conductor is designed into four inclined planes, and the purpose of the heat conductor is to reduce heat leakage, so that heat is better concentrated on the upper surface of the heat conducting channel at the top end; a plurality of heating bodies 6 are distributed at the bottom of the heat collection body, generally ceramic heating sheets are adopted and are arranged according to the temperature zone range of a tested sample, 8 heating sheets are arranged at the position, the single-chip resistance is 12.4 omega, the rated voltage is 12V, and the size is 10 multiplied by 1.2 mm; in the actual test process, the surface of the high heat-conducting plate 8 is tightly attached to the upper surface of the heat transfer channel of the heat collector, and the temperature of the contact surface of the high heat-conducting plate and the upper surface of the heat transfer channel of the heat collector is approximately the same, which is denoted by T0; the high heat-conducting fin and the metal heat sink material are generally connected by gluing or welding, so that the middle connecting layer 9 is also the core for determining the whole interface thermal resistance; and arranging temperature measuring points on the back surface of the high heat-conducting strip-metal heat sink sample 10 to be tested, and collecting the temperature T4 of the heat sink surface in the testing process.
The device is adopted to test the diamond sheet-aluminum heat sink packaging structures in three different welding modes. The diamond size of the sample to be tested is 10 multiplied by 1mm, the aluminum sheet size is 25 multiplied by 2mm, and the welding materials are PbIn, AuSn and SnInAg respectively. At an input power of 8W/cm2Under the conditions, the measured thermal resistance values were respectively: the PbIn interface is 4.94 ℃/W, the AuSn solder interface thermal resistance is 6.39 ℃/W, and the SnInAg is 7.25 ℃/W. It can be seen that in the test process, the PbIn solder shows the best interface heat transfer effect, and the interface heat transfer is the worst SnInAg solder after AuSn. In addition, the temperature change test is carried out on the sample to be tested, namely the temperature change test is carried out on different samples by applying the same power density, and then the time change rule of the surface temperature T4 of the metal heat sink is recorded. By comparing the temperature rise curves of two different systems, the thermal resistance of the connecting interface can be qualitatively analyzed. FIG. 3 shows the power density at input of 8W/cm2Under the condition, the temperature rise curve obtained by two different interface connection systems shows that the temperature rise of the curve b is obviously faster than that of the curve a, which shows that the interface thermal resistance of the curve b is low and the heat transfer effect is better.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (2)
1. A high conducting strip-metal heat sink interface thermal resistance measuring device is characterized in that: the solar heat collector comprises an adjustable direct current power supply (1), a heat collecting system (2), a heat collecting body (3), a heat insulating material (4) and a temperature data acquisition system (5), wherein the adjustable direct current power supply (1) is connected with the heat collecting system (2), the temperature data acquisition system (5) acquires data of the heat collecting system (2), the heat collecting body (3) is arranged in the heat collecting system (2), and the heat insulating material (4) is wrapped around the heat collecting body (3);
three temperature measuring points are equidistantly distributed on the heat collecting body (3), and a high-precision thermocouple is arranged on each temperature measuring point for temperature measurement;
the heat collection body (3) comprises a heating body (6), a heat transfer material (7), high heat conducting fins (8) and a connecting layer (9), the heat transfer material (7) is arranged around the heating body (6), the high heat conducting fins (8) are arranged between the heat transfer material (7) and the connecting layer (9), the surfaces of the high heat conducting fins (8) are tightly attached to the upper surface of a heat transfer channel of the heat collection body (3), and the upper surface of the heat transfer material (7) is provided with four inclined planes;
the heating body (6) is processed in parallel and is connected to the output end of the power supply through a lead after being connected in parallel; the heating body (6) is sealed by a cover plate and is fixed in a groove on the lower surface of the heat collecting body (3);
the method for measuring by adopting the device comprises the following steps: the upper surface of the heat collector (3) is a working surface, the surface of a high heat conducting sheet-metal heat sink sample to be measured is directly contacted with the working surface of the heat collector (3), three temperature measuring points on the heat collector (3) are provided with high-precision thermocouples for temperature measurement, and the temperature is recorded by a temperature data acquisition system (5); the method comprises the following steps that one side of a metal heat sink surface of a high-thermal-conductivity sheet-metal heat sink sample to be measured is also provided with another high-precision thermocouple for temperature acquisition; during testing, firstly, the room temperature is kept stable, and all temperature measuring points are at the same temperature before heating; after heating, the temperature of each point gradually rises, and after the temperature of each temperature point is kept stable, the temperature of each point is recorded as the calculated temperature.
2. The device for measuring the interfacial thermal resistance of the high-thermal-conductivity sheet-metal heat sink according to claim 1, wherein: the heat collecting body (3) is sealed in the shell of the heat collecting system (2), and the middle of the shell of the heat collecting system (2) is filled with a heat-insulating material (4).
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| CN110907490B (en) * | 2019-11-28 | 2022-02-11 | 航天特种材料及工艺技术研究所 | Device and method for testing heat conductivity of high-heat-conductivity material |
| CN111289562B (en) * | 2020-04-01 | 2023-03-14 | 北京工业大学 | Structure and testing method of thin-layer thermal resistance testing probe |
| CN111579587B (en) * | 2020-06-22 | 2023-05-30 | 青岛中加特电气股份有限公司 | Detection device and detection method for detecting thermal resistance of heat conducting material |
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| CN104407280A (en) * | 2014-12-01 | 2015-03-11 | 苏州立瓷电子技术有限公司 | Thermal resistance measuring method of LED lamp |
| CN105843979A (en) * | 2016-01-22 | 2016-08-10 | 厦门大学 | Measuring method of thermal coupling and junction temperature distribution among chips in LED multi-chip module |
| CN107421980A (en) * | 2017-02-04 | 2017-12-01 | 青岛大学 | Heating impedance compensation type thermo-resistance measurement method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407280A (en) * | 2014-12-01 | 2015-03-11 | 苏州立瓷电子技术有限公司 | Thermal resistance measuring method of LED lamp |
| CN105843979A (en) * | 2016-01-22 | 2016-08-10 | 厦门大学 | Measuring method of thermal coupling and junction temperature distribution among chips in LED multi-chip module |
| CN107421980A (en) * | 2017-02-04 | 2017-12-01 | 青岛大学 | Heating impedance compensation type thermo-resistance measurement method |
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