阅读说明：本技术 一种导热脂的热阻测量装置及方法 (Thermal resistance measuring device and method for thermal grease ) 是由 张旭 陈玉军 于惠 刘凯 李通 唐亚彬 吴荣亮 黄杨坤 于 2019-09-12 设计创作，主要内容包括：本发明属于热阻测量技术领域,具体涉及一种导热脂的热阻测量装置及方法。包括：模拟热源,设有发热端接触面和发热端测试孔；热沉,设有冷端接触面和冷端测温孔；连接组件,用于上下连接所述模拟热源和所述热沉连接组件并且使得所述模拟热源的发热端接触面和所述热沉的冷端接触面相对设置。热电偶探头可以经由所述冷端测试孔和发热端测试孔分别抵达发热端接触面和冷端接触面直接测量导热界面处的温度,不需要构建热传导路径,相应的不存在热传导路径上存在温度梯度导致超出导热脂工作温度范围的情况,相应的也不需要额外对热传导路径进行保温的装置。不仅提高的测量精度,还简化了测量装置的结构。(The invention belongs to the technical field of thermal resistance measurement, and particularly relates to a thermal resistance measurement device and method for thermal grease. The method comprises the following steps: the simulated heat source is provided with a heating end contact surface and a heating end test hole; the heat sink is provided with a cold end contact surface and a cold end temperature measuring hole; and the connecting assembly is used for connecting the simulated heat source and the heat sink connecting assembly up and down and enabling the heating end contact surface of the simulated heat source and the cold end contact surface of the heat sink to be arranged oppositely. The thermocouple probe can reach the heating end contact surface and the cold junction contact surface respectively through the cold end test hole and the heating end test hole and directly measure the temperature of the heat conduction interface, a heat conduction path does not need to be constructed, the condition that the temperature gradient exists on the heat conduction path and exceeds the working temperature range of the heat conduction grease does not exist correspondingly, and a device for preserving heat of the heat conduction path does not need to be additionally arranged correspondingly. Not only improved measurement accuracy has still simplified measuring device's structure.)

1. A thermal resistance measuring device of a thermal grease, comprising:

the simulated heat source is provided with a heating end contact surface and a heating end test hole;

the heat sink is provided with a cold end contact surface and a cold end temperature measuring hole;

the connecting assembly is used for connecting the simulated heat source and the heat sink up and down and enabling a heating end contact surface of the simulated heat source to be opposite to a cold end contact surface of the heat sink;

the heating end test hole extends from the end part of the simulated heat source opposite to the heating end contact surface and penetrates through the heating end contact surface;

the cold end test hole extends from the end part of the simulated heat source opposite to the cold end contact surface and penetrates through the cold end contact surface;

and the thermocouple temperature measuring part comprises a thermocouple probe with the diameter smaller than the diameter of the cold end testing hole and the diameter of the heating end testing hole.

2. The thermal resistance measuring device of thermal grease as claimed in claim 1, wherein:

the simulated heat source comprises a heat conductor and a heating device;

the heating end contact surface is one end surface of the heat conductor, and the heating devices are distributed on other end surfaces or side surfaces of the heat conductor except the heating end contact surface.

3. The thermal resistance measuring device of thermal grease as claimed in claim 2, wherein:

the heat conductor is a copper block with a cubic structure.

4. The thermal resistance measuring device of thermal grease as claimed in claim 2, wherein:

the heating device is a semiconductor heating chip.

5. The thermal resistance measuring device of thermal grease as claimed in claim 2, wherein:

the simulated heat source further comprises a housing;

the shell comprises a concave part and mounting plates positioned on two sides of the concave part;

the heat conductor is mounted in the recess and the heat generating end contact surface faces the opening of the recess.

6. The thermal resistance measuring device of thermal grease as claimed in claim 5, wherein:

the mounting plate is provided with a heating end mounting hole, and the heat sink is provided with a cold end mounting hole corresponding to the heating end mounting hole;

the connecting component is a connecting bolt.

7. The thermal resistance measuring device of thermal grease as claimed in claim 1, wherein:

the maximum heating power of the simulated heat source is 800W.

8. The thermal resistance measuring device of thermal grease as claimed in claim 1, wherein:

the heat sink comprises a boss with the cold end contact surface and a cooling water circulation loop for cooling the boss.

9. The thermal resistance measuring device of thermal grease as claimed in claim 1, wherein:

the diameter of the heating end test hole is smaller than 1.2mm, and the diameter of the cold end test hole is smaller than 1.2 mm;

the diameter of the thermocouple probe is less than 0.6 mm.

10. A thermal resistance measuring method of a thermal grease, which is applied to the thermal resistance measuring apparatus according to any one of claims 1 to 8, comprising:

step S0, starting the heat sink and waiting for the stable operation;

step S1, coating heat-conducting grease on the cold end contact surface of the heat sink;

step S2, connecting the simulated heat source with the heat sink through the connecting component;

step S3, inserting the test probe of the first thermocouple temperature measurement piece into the heating end test hole to contact with the cold end contact surface, and inserting the test probe of the second thermocouple temperature measurement piece into the cold end test hole to contact with the heating end contact surface;

step S4, turning on the simulated heat source;

step S5, recording the test temperature T1 of the first thermocouple temperature measuring piece and the test temperature T2 of the second thermocouple temperature measuring piece after the temperature is stable;

step S6, calculating interface thermal resistance；

Wherein, W is the heat flow density, and a is the heat sink/heat source heat conductivity coefficient.

Technical Field

The invention belongs to the technical field of thermal resistance measurement, and particularly relates to a thermal resistance measurement device and method for thermal grease.

Background

The existing thermal contact resistance scheme is generally to construct a one-dimensional steady-state heat conduction interval, to measure the temperature on a conduction path, to estimate the temperature at two ends of an interface to be measured, and to obtain the thermal grease interface resistance through measurement and calculation. For example, the invention patent application published in application publication No. CN108007964A, 5/8/2018 discloses a thermal contact resistance testing device and a testing method, wherein a plurality of test pieces are butted up and down pairwise to form a time combination with the same contact area and different contact areas, so that the thermal contact resistance testing device and the testing method are used for testing the thermal contact resistance under different contact surface areas and the thermal contact resistance under different heating stabilities.

However, the working temperature of the heat-conducting grease generally used for the electronic chip is between 30 and 80 ℃, and the heat flow density of the electronic chip with high heat flow density reaches 100W/cm². In this case, even if a one-dimensional steady-state heat conduction path is constructed using a copper bar as in CN108007364A, it is at 100W/cm²The temperature gradient on the conduction path has also reached 25 c/cm at the heat flow density of (2). And thus the contact resistance cannot be measured at a suitable operating temperature of the thermal grease. Because the constructed one-dimensional steady-state heat conduction path is long, the temperature difference between two ends is very high under high heat flow density, so that an additional heat preservation device is needed, and meanwhile, the temperature measurement error is large. In addition, since the thermal conductivity of the material on the thermal conduction path is determined according to the material characteristics rather than the measured value, and the thermal conductivity is related to the temperature, this may cause measurement errors.

Disclosure of Invention

The invention provides a thermal resistance measuring device and method of thermal grease, aiming at measuring thermal contact resistance in the actual working temperature and heat flow range of the thermal grease and improving the measuring precision.

A thermal resistance measuring device of a thermal grease, comprising:

the simulated heat source is provided with a heating end contact surface and a heating end test hole;

the heat sink is provided with a cold end contact surface and a cold end temperature measuring hole;

the connecting assembly is used for connecting the simulated heat source and the heat sink connecting assembly up and down and enabling a heating end contact surface of the simulated heat source and a cold end contact surface of the heat sink to be arranged oppositely;

the heating end test hole extends from the end part of the simulated heat source opposite to the heating end contact surface and penetrates through the heating end contact surface;

the cold end test hole extends from the end part of the simulated heat source opposite to the cold end contact surface and penetrates through the cold end contact surface;

and the thermocouple temperature measuring part comprises a thermocouple probe with the diameter smaller than the diameter of the cold end testing hole and the diameter of the heating end testing hole.

In the technical scheme, the thermocouple probe can respectively reach the heating end contact surface and the cold end contact surface through the cold end test hole and the heating end test hole to directly measure the temperature of the heat conduction interface, a heat conduction path does not need to be constructed, the condition that the temperature gradient exists on the heat conduction path to exceed the working temperature range of the heat conduction grease does not exist correspondingly, and a device for preserving heat of the heat conduction path does not need to be additionally arranged correspondingly. Not only improved measurement accuracy has still simplified measuring device's structure.

Preferably, the simulated heat source comprises a heat conductor and a heating device; the heating end contact surface is one end surface of the heat conductor, and the heating devices are distributed on other end surfaces or side surfaces of the heat conductor except the heating end contact surface.

Preferably, the heat conductor is a copper block having a cubic structure.

Preferably, the heating device is a semiconductor heating chip. The semiconductor heating device is used for simulating the chip to heat, the precision is high, and the power adjustment is convenient.

Preferably, the simulated heat source further comprises a housing; the shell comprises a concave part and mounting plates positioned on two sides of the concave part; the heat conductor is mounted in the recess and the heat generating end contact surface faces the opening of the recess.

Preferably, the mounting plate is provided with a heating end mounting hole, and the heat sink is provided with a cold end mounting hole corresponding to the heating end mounting hole; the connecting component is a connecting bolt.

Preferably, the heating power of the simulated heat source is at most 800W.

Preferably, the heat sink comprises a boss provided with the cold end contact surface and a cooling water circulation loop for cooling the boss. The cooling water circulation loop ensures that the temperature of the cold end contact surface is controllable and is 100W/cm²The lowest heat flow density can control the temperature of the cold end contact surface to be about 40 ℃, thereby realizing the measurement range of 40 ℃ to 80 ℃.

Preferably, the diameter of the test hole at the heating end is smaller than 1.2mm, and the diameter of the test hole at the cold end is smaller than 1.2 mm; the diameter of the thermocouple probe is less than 0.6 mm. The accuracy and consistency of the measurement can be ensured.

The present invention also provides a thermal resistance measuring method of a thermal grease, which is characterized in that the thermal resistance measuring method is applied to any one of the thermal resistance measuring apparatuses, and the thermal resistance measuring apparatus comprises:

step S0, turn on the heat sink and wait for its operation to stabilize.

Step S1, coating heat-conducting grease on the cold end contact surface of the heat sink;

step S2, connecting the simulated heat source with the heat sink through the connecting component;

step S3, inserting the test probe of the first thermocouple temperature measurement piece into the heating end test hole to contact with the cold end contact surface, and inserting the test probe of the second thermocouple temperature measurement piece into the cold end test hole to contact with the heating end contact surface;

step S4, turning on the simulated heat source;

step S5, recording the test temperature T1 of the first thermocouple temperature measuring piece and the test temperature T2 of the second thermocouple temperature measuring piece after the temperature is stable;

step S6, calculating interface thermal resistance;

wherein, W is the heat flow density, and a is the heat sink/heat source heat conductivity coefficient.

The invention has the following beneficial effects:

1. the thermocouple probe can reach the heating end contact surface and the cold junction contact surface respectively through the cold end test hole and the heating end test hole and directly measure the temperature of the heat conduction interface, a heat conduction path does not need to be constructed, the condition that the temperature gradient exists on the heat conduction path and exceeds the working temperature range of the heat conduction grease does not exist correspondingly, and a device for preserving heat of the heat conduction path does not need to be additionally arranged correspondingly. Not only improved measurement accuracy has still simplified measuring device's structure.

2. The maximum heating power of a single simulation heat source can reach 800W, a semiconductor heating device is used for simulating a chip to heat, the precision is high, and the power adjustment is convenient.

3. The cooling water circulation loop of the heat sink ensures that the temperature of the cold end contact surface is controllable and is 100W/cm²The lowest heat flow density can control the temperature of the cold end contact surface to be about 40 ℃, thereby realizing the measurement range of 40 ℃ to 80 ℃.

Drawings

Fig. 1 is a first schematic structural diagram of a simulated heat source according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a simulated heat source according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram three of a simulated heat source according to an embodiment of the present application.

Fig. 4 is a first schematic view of a heat sink structure according to an embodiment of the present application.

Fig. 5 is a schematic diagram of a heat sink structure according to an embodiment of the present application.

Fig. 6 is a schematic diagram of a heat sink structure according to an embodiment of the present application.

Fig. 7 is a first cross-sectional view of a thermal resistance measuring device of an embodiment of the present application in use.

Detailed Description

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that the conventional terms should be interpreted as having a meaning that is consistent with their meaning in the relevant art and this disclosure. The present disclosure is to be considered as an example of the invention and is not intended to limit the invention to the particular embodiments.