Device for measuring contact thermal resistance of liquid metal

Abstract

The invention relates to the technical field of thermal resistance measurement, and particularly discloses a liquid metal contact thermal resistance measuring device which comprises a heat dissipation end assembly, a motion control assembly, a grating assembly, a driving end assembly, a transmission assembly, a supporting and guiding assembly and a temperature sensor. The relative contact surfaces are used for clamping liquid metal coated between the relative contact surfaces, the heat dissipation end assembly is used for measuring the heat conduction performance of the liquid metal in the relative contact surfaces and connected to one end of the supporting and guiding assembly, and the driving end assembly is arranged in a sliding mode relative to the heat dissipation end assembly. The sides, close to the opposite contact faces, of the heat dissipation end assembly and the driving end assembly are connected with temperature sensors, and the grating assembly is connected with the driving end assembly. According to the contact thermal resistance measuring device, the film thickness of the liquid metal to be measured can be steplessly adjusted, the contact thermal resistance of different film thicknesses can be measured, and data support is provided for selection of the film thickness of the liquid metal.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of thermal resistance measurement, and particularly relates to a contact thermal resistance measurement device for liquid metal. BACKGROUND

[0002] In the process of rapid development of modern science and technology, many fields have put forward strict requirements for heat dissipation technology. Miniaturization of electronic devices makes internal components more compact, and high power brings a large amount of heat accumulation. According to relevant data, when the power density of a chip exceeds 100 W / cm 2 , if heat dissipation is not timely, the temperature of the chip can rise sharply to above 100 DEG C in a short time, which seriously affects its performance and service life. In the field of aerospace, key components such as aircraft engines generate extremely high heat when running, and there is a high expectation for the efficiency and reliability of the heat dissipation system. As a new type of thermal interface material, liquid metal can solve the heat dissipation problem due to its excellent high thermal conductivity and good fluidity. For example, the thermal conductivity of gallium-based liquid metal can reach 25-35 W / (m.K), which is much higher than that of traditional silicone grease-based thermal interface material, providing the possibility for efficient heat dissipation.

[0003] Accurate understanding of the contact thermal resistance of liquid metal under different film thicknesses is extremely crucial for optimizing the design of thermal interface materials. As an important parameter for measuring the degree of heat transfer resistance, the accurate determination of the thermal resistance value helps to accurately evaluate the heat dissipation efficiency of liquid metal in practical application. The heat transfer mechanism of liquid metal under different film thicknesses will change significantly. Thin film thickness may highlight quantum effects, while thick film thickness tends to be closer to the traditional heat conduction mode. Therefore, obtaining the contact thermal resistance data corresponding to different film thicknesses can provide solid data support for the selection and application of thermal interface materials under different working conditions, thereby effectively improving the heat dissipation efficiency and meeting the needs of various fields for efficient heat dissipation.

[0004] The existing measuring device can only achieve limited level of film thickness adjustment in film thickness control, and it is difficult to achieve the precision requirement of stepless control. The common method of coating liquid metal with fixed pitch mold cannot flexibly adjust the film thickness according to the experimental requirements, which hinders the continuous influence of different film thicknesses on thermal resistance. In the contact thermal resistance measurement process, the measurement accuracy of the existing technology is seriously insufficient. The traditional device for measuring contact thermal resistance based on the steady-state method has a measurement error of up to 20%-30% due to the interference of environmental temperature fluctuations, non-ideal contact between the sample and the test plate, and other factors, which cannot provide reliable thermal resistance data. Moreover, some measuring devices cannot simultaneously control the film thickness and measure the thermal resistance, which greatly reduces the accuracy and reliability of the experimental results, and cannot meet the needs of in-depth research on the thermal performance of liquid metal in scientific research and industrial production. Therefore, it is urgent to develop a device that can accurately and steplessly control the film thickness of liquid metal and accurately measure the corresponding contact thermal resistance under different film thicknesses, which has far-reaching practical significance for promoting the development of thermal interface materials and improving the heat dissipation technology level in various fields. SUMMARY

[0005] The purpose of the present application is to provide a contact thermal resistance measuring device for liquid metal, which can steplessly adjust the film thickness of the liquid metal to be measured and measure the corresponding contact thermal resistance under different film thicknesses, providing data support for film thickness selection of liquid metal.

[0006] The purpose of the present application can be achieved by the following technical solutions: A contact thermal resistance measuring device for liquid metal, comprising a heat dissipation end assembly, a motion control assembly, a grating assembly, an active end assembly, a transmission assembly, a support and guide assembly, and a temperature sensor, the heat dissipation end assembly and the active end assembly have a relative contact surface, the relative contact surface is used to clamp the liquid metal coated between the relative contact surfaces, the active end assembly is used to heat the liquid metal in the relative contact surface, the heat dissipation end assembly is used to measure the heat conduction performance of the liquid metal in the relative contact surface, the heat dissipation end assembly is connected to one end of the support and guide assembly, the active end assembly is slidingly arranged relative to the heat dissipation end assembly, the heat dissipation end assembly and the active end assembly are both connected with the temperature sensor on the side close to the relative contact surface, the heat dissipation end assembly and the active end assembly measure the temperature at the installation point of the temperature sensor through the temperature sensor, one end of the transmission assembly is connected with the active end assembly, the other end of the transmission assembly is connected with the motion control assembly, the motion control assembly controls the relative sliding distance between the active end assembly and the heat dissipation end assembly through the transmission assembly, the grating assembly is connected with the active end assembly, and the grating assembly is used to detect the size of the relative sliding distance.

[0007] In a further aspect, the heat dissipation end assembly comprises a first base plate, a water-cooled copper pipe, a first fixing seat, a heat dissipation end copper rod, a first linear bearing, a cooling copper plate and a pressure sensor, the inner ring of the first linear bearing is connected with the support and guide assembly, the first base plate is connected with the outer ring of the first linear bearing, the pressure sensor is connected between the first base plate and the support and guide assembly, and the pressure sensor is located on the side of the first base plate away from the driving end assembly, the cooling copper plate is connected on the side of the first base plate away from the pressure sensor, the first fixing seat is connected on the side of the cooling copper plate away from the first base plate, one end of the heat dissipation end copper rod forms the opposite contact surface with the driving end assembly, the other end of the heat dissipation end copper rod is connected with the cooling copper plate through the first fixing seat, the water-cooled copper pipe is in heat conduction with the heat dissipation end copper rod through the cooling copper plate, and the end of the heat dissipation end copper rod close to the driving end assembly is provided with a point for mounting the temperature sensor.

[0008] In a further aspect, the driving end assembly comprises a heating sheet, a second linear bearing, a second fixing base, a test copper rod, a second base plate and a heat insulation bushing, the inner ring of the second linear bearing is connected with the support and guide assembly, the second base plate is connected with the outer ring of the second linear bearing, one end of the test copper rod is arranged opposite to one end of the heat dissipation end copper rod, and the opposite ends form the opposite contact surface, the other end of the test copper rod is inserted into the second fixing base, the second fixing base is connected with the second base plate and located on the side of the second linear bearing, the heating sheet is inserted into the second fixing base and connected with the other end of the test copper rod, and the heat insulation bushing is connected between the heating sheet and the second fixing base and used for heat insulation between the heating sheet and the second fixing base.

[0009] In a further aspect, the motion control assembly comprises a box base plate, a motor protection cover plate, a motor support seat and a ball screw actuator, the motor support seat is connected on the box base plate, the ball screw actuator is installed on the motor support seat, the screw rod of the ball screw actuator is connected with the transmission assembly outside the motor support seat, the motor protection cover plate is arranged between the motor of the ball screw actuator and the opposite contact surface, and the motor protection cover plate is provided with a groove for collecting the liquid metal.

[0010] In a further aspect, the motor support seat comprises a rib plate and a support plate, the support plate is connected on the box base plate, and the rib plate is arranged between the support plate and the box base plate; the side of the motor of the ball screw actuator is provided with a motor protection side plate.

[0011] Further, the transmission assembly comprises a gland, an H-shaped connecting shaft, a transmission base, a third linear bearing, a screw rod connecting seat and a linkage seat, the screw rod connecting seat is threadedly connected with a screw rod of a ball screw actuator, one side of the screw rod of the ball screw actuator is provided with the third linear bearing, the inner ring of the third linear bearing is guidingly connected with a support guide assembly, the outer ring of the third linear bearing is connected with the screw rod connecting seat, the linkage seat is connected with the screw rod connecting seat and is located above the outer ring of the screw rod of the ball screw actuator and the third linear bearing, one side of the H-shaped connecting shaft is arranged on the end of the linkage seat away from the screw rod connecting seat, the gland is pressed on the H-shaped connecting shaft, one side of the H-shaped connecting shaft is pressed on the linkage seat through the gland, the other side of the H-shaped connecting shaft is connected with one side of the transmission base, the transmission base is rotationally connected with the linkage seat through the H-shaped connecting shaft, the other side of the transmission base is connected with the second bottom plate away from the second fixed base.

[0012] Further, the H-shaped connecting shaft comprises a shaft rod, a rotating shaft, a locking nut, a rolling bearing and a disc spring, the shaft rod is at least two, one end of the shaft rod is sequentially threaded through the rolling bearing and the disc spring and is connected with the locking nut, the middle parts of the two shaft rods are rotationally connected in the rotating shaft through the rolling bearing, the middle parts of the two shaft rods are connected with the rotating shaft through the bearing to form an H shape, the other ends of the shaft rods are provided with shaft shoulders, the shaft shoulders are locked with the inner rings of the rolling bearings through the locking nuts and the disc springs, the shaft shoulder and the locking nut of one of the shaft rods are pressed on the linkage seat through the gland, and the shaft shoulder and the locking nut of the other shaft rod are pressed on the transmission base.

[0013] Further, the support guide assembly comprises a screw rod guide shaft, a fixed seat guide shaft, a box side plate, a guide shaft positioning plate and a top block, the box side plate is arranged on one side of the guide shaft positioning plate, the guide shaft positioning plate and the box side plate are connected on the box bottom plate, the fixed seat guide shaft is connected between the two guide shaft positioning plates and guides the sliding directions of the driving end assembly and the heat dissipation end assembly through the sliding connection with the inner rings of the second linear bearing and the first linear bearing, the screw rod guide shaft is connected between the guide shaft positioning plate and the motor support seat and guides the sliding direction of the transmission assembly through the sliding connection with the inner ring of the third linear bearing, the screw rod guide shaft and the fixed seat guide shaft are parallel to each other, and the end parts of the screw rod guide shaft and the fixed seat guide shaft are limited on the guide shaft positioning plate and the motor support seat through the top block; the support guide assembly further comprises a handle, the handle is arranged outside the box side plate, and the support guide assembly is transported through the handle.

[0014] In a further scheme, the grating assembly comprises a grating ruler, an origin selector, a reading head, and a reading head mounting frame, the reading head is connected with the reading head mounting frame, the reading head mounting frame is connected with the driving end assembly, the grating ruler and the origin selector are arranged on one side of the reading head, and the grating ruler is relatively parallel to the driving end assembly and slides; the grating ruler is used for measuring the sliding distance of the reading head, and the origin selector is used for zero calibration of the starting position of the reading head.

[0015] In a further scheme, a limit switch assembly is further arranged on the sliding direction of the driving end assembly, and is used for limiting the sliding end position of the driving end assembly.

[0016] The present application has the following beneficial effects: The present application provides a performance testing device for liquid metal with different film thicknesses, and the contact thermal resistance data of the liquid metal with different film thicknesses can be used for selecting appropriate liquid metal and film thickness in actual heat conduction.

[0017] The present application utilizes the one-to-one correspondence between the thickness and pressure of the liquid metal, and designs a contact thermal resistance measuring device for liquid metal, which controls the thickness of the liquid metal by controlling the pressure between the two contact surfaces of the heat dissipation end assembly and the driving end assembly, controls the contact pressure by forming a closed loop motor drive between the ball screw actuator and the grating assembly, and feeds back the pressure between the two contact surfaces through the pressure sensor, so as to realize stepless adjustment of the liquid metal with different film thicknesses by utilizing the one-to-one correspondence between the pressure and the thickness, and measure the contact thermal resistance of the liquid metal with the film thickness between the two contact surfaces of the heat dissipation end assembly and the driving end assembly after adjustment, so as to obtain the contact thermal resistance of the liquid metal with the film thickness, and obtain the contact thermal resistance measurement data of the liquid metal with different film thicknesses by adjusting and obtaining the liquid metal with different film thicknesses and measuring, so as to ensure that the error of the adjusted film thickness is small during the measurement process by keeping the contact pressure error between the two contact surfaces small through the transmission assembly and the support guide assembly.

[0018] The transmission assembly of the present application adopts H-shaped connecting shaft to rotatably connect the linkage seat and the second bottom plate, and the H-shaped connecting shaft is rotatably connected by using a rolling bearing, if the transmission assembly directly connects the linkage seat and the second bottom plate by using a connecting rod, the connecting rod will be deformed due to tension, and the movable bottom plate will be deflected due to the deformation of the connecting rod, so as to cause the axis of the test copper bar to be inconsistent with the axis of the guide shaft, which can reduce the deformation of the second bottom plate and the linkage seat due to stress when they are directly connected, so as to cause the contact surface between the test copper bar and the heat dissipation end copper bar to be uneven or the stress to be uneven.

[0019] During the measurement of the contact thermal resistance, the test copper bar and the heat dissipation end copper bar are nickel-plated copper bars, temperature sensors are distributed on the nickel-plated copper bars, one end of the copper bar is heated during the experiment, and the other end is cooled, and the contact thermal resistance of the liquid metal is calculated by measuring the change of the temperature value.

[0020] In order to prevent the liquid metal from corroding the motor below, a motor protection cover is designed, and the motor protection cover above can also recycle the liquid metal to reuse. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is an external schematic diagram of a liquid metal contact thermal resistance measuring device in an embodiment of the present application; Figure 2 is an internal schematic diagram of a liquid metal contact thermal resistance measuring device in an embodiment of the present application; Figure 3 is a schematic diagram of a heat dissipation end assembly in an embodiment of the present application; Figure 4 is a schematic diagram of a motion control assembly in an embodiment of the present application; Figure 5 is a schematic diagram of a grating assembly in an embodiment of the present application; Figure 6 is a schematic diagram of a main end assembly in an embodiment of the present application; Figure 7 is a schematic diagram of a transmission assembly in an embodiment of the present application; Figure 8 is a schematic diagram of an H-shaped connecting shaft in an embodiment of the present application; Figure 9 is a schematic diagram of a support and guide assembly in an embodiment of the present application; In the figure: 1. Heat dissipation end assembly; 101. First base plate; 102. Water-cooled copper tube; 103. First fixed seat; 104. Heat dissipation end copper rod; 105. First linear bearing; 106. Cooling copper plate; 107. Pressure sensor; 2. Motion control assembly; 201. Box bottom plate; 202. Motor protection cover; 203. Motor support seat; 204. Ball screw actuator; 205. Motor protection side plate; 3. Grating assembly; 301. Grating scale; 302. Origin selector; 303. Reading head; 304. Reading head mounting bracket; 4. Active end assembly; 401. Heating plate; 402. Second linear bearing; 403. Second Fixed base; 404, test copper rod; 405, second base plate; 406, thermal insulation bearing; 5, transmission assembly; 501, pressure cover; 502, H-shaped connecting shaft; 5021, shaft; 5022, rotating shaft; 5023, locking nut; 5024, rolling bearing; 5025, disc spring; 503, transmission base; 504, third linear bearing; 505, screw connecting seat; 506, linkage seat; 6, support guide assembly; 601, screw guide shaft; 602, fixed seat guide shaft; 603, box side panel; 604, guide shaft positioning plate; 605, top block; 7, limit switch assembly; 8, temperature sensor; 9, handle. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] like Figure 1 As shown, a liquid metal contact thermal resistance measuring device includes a heat dissipation end component 1, a motion control component 2, a grating component 3, an active end component 4, a transmission component 5, a support guide component 6 and a temperature sensor 8. There is a contact between the heat dissipation end component 1 and the active end component 4. Figure 2The relative contact surface is used to clamp the liquid metal coated between the relative contact surface, the active end assembly 4 is used to heat the liquid metal in the relative contact surface, the heat dissipation end assembly 1 is used to measure the heat conduction performance of the liquid metal in the relative contact surface, the heat dissipation end assembly 1 is connected at one end of the support guide assembly 6, the active end assembly 4 is arranged to slide relative to the heat dissipation end assembly 1, the heat dissipation end assembly 1 and the active end assembly 4 are connected with the temperature sensor 8 on the side close to the relative contact surface, the heat dissipation end assembly 1 and the active end assembly 4 measure the temperature at the installation point of the temperature sensor 8 through the temperature sensor 8, one end of the transmission assembly 5 is connected with the active end assembly 4, the other end of the transmission assembly 5 is connected with the motion control assembly 2, the motion control assembly 2 controls the relative sliding distance between the active end assembly 4 and the heat dissipation end assembly 1 through the transmission assembly 5, the grating assembly 3 is connected with the active end assembly 4, and the grating assembly 3 is used to detect the size of the relative sliding distance.

[0025] In some embodiments, the heat dissipation end assembly 1 comprises as Figure 3 The first bottom plate 101, the water-cooled copper pipe 102, the first fixed seat 103, the heat dissipation end copper rod 104, the first linear bearing 105, the cooling copper plate 106 and the pressure sensor 107 are shown, the inner ring of the first linear bearing 105 is connected with the support guide assembly 6, the first bottom plate 101 is connected with the outer ring of the first linear bearing 105, the pressure sensor 107 is connected between the first bottom plate 101 and the support guide assembly 6, and the pressure sensor 107 is located on the side of the first bottom plate 101 away from the active end assembly 4, the cooling copper plate 106 is connected on the side of the first bottom plate 101 away from the pressure sensor 107, the first fixed seat 103 is connected on the side of the cooling copper plate 106 away from the first bottom plate 101, one end of the heat dissipation end copper rod 104 forms the relative contact surface with the active end assembly 4, the other end of the heat dissipation end copper rod 104 passes through the first fixed seat 103 and is connected with the cooling copper plate 106, the water-cooled copper pipe 102 is connected with the heat dissipation end copper rod 104 through the cooling copper plate 106, and the heat dissipation end copper rod 104 is provided with a point for installing the temperature sensor 8 on the end close to the active end assembly 4.

[0026] Three first linear bearings 105 can be fastened on the first bottom plate 101 by screws, the water-cooled copper pipe 102 is installed into the corresponding groove of the cooling copper plate 106, the cooling copper plate 106 is fixed on the first bottom plate 101, and the water-cooled copper pipe 102 is pressed and attached to the surface of the cooling copper plate 106. As shown in Figure 9The shown fixed seat guide shaft 602 passes through three first linear bearings 105, and plays a guiding role when the fixed end is displaced by force, so that the heat dissipation end copper rod 104 is evenly stressed when contacting the end face. The heat dissipation end copper rod 104 passes through the first fixed seat 103, and a limiting boss is provided at the end, which cooperates with the corresponding groove of the first fixed seat 103. The first fixed seat 103 can be fastened to the cooling copper plate 106 by four screws, and the end face of the limiting boss of the heat dissipation end copper rod 104 is pressed against the surface of the cooling copper plate 106. At the same time, 5 platforms can be provided on the heat dissipation end copper rod 104 for installing the temperature sensor 8 to obtain the temperature at the corresponding point. The water-cooled copper pipe 102 is connected to the external circulating water source, and a clamp is used to lock the joint to remove the heat that interferes with the experimental error. One end of the pressure sensor 107 is fixed to the first base plate 101 by screws, and the other end can be fixed as shown in FIG. Figure 9 On the guide shaft positioning plate 604 shown, since the friction between the first linear bearing 105 and the fixed seat guide shaft 602 is very small and can be ignored, when the heat dissipation end assembly 1 is subjected to force, the pressure sensor 107 is compressed and deformed, and the pressure sensor 107 can directly measure the pressure transmitted by the heat dissipation end copper rod 104 along the axis.

[0027] In some embodiments, the active end component 4 includes: Figure 6 The heating plate 401, the second linear bearing 402, the second fixed base 403, the test copper rod 404, the second base plate 405 and the thermal insulation bearing 406 are shown. The inner ring of the second linear bearing 402 is guide-connected to the support guide assembly 6, the second base plate 405 is connected to the outer ring of the second linear bearing 402, one end of the test copper rod 404 is arranged opposite to one end of the heat dissipation end copper rod 104, and the relative contact surface is formed at the opposite end, the other end of the test copper rod 404 is inserted into the second fixed base 403, the second fixed base 403 is connected to the end of the second base plate 405 close to the heat dissipation end copper rod 104, and is located on the side of the second linear bearing 402, the heating plate 401 is inserted into the second fixed base 403 and connected to the other end of the test copper rod 404, the thermal insulation bearing 406 is connected between the heating plate 401 and the second fixed base 403 and is used to insulate the two.

[0028] During the experiment, liquid metal is generally dripped onto the contact end surface of the heat dissipation end copper rod 104 and the test copper rod 404 using a dispensing machine similar to a syringe. The liquid metal is evenly spread over the experimental surface due to the surface tension of the liquid metal. The second linear bearing 402 is fastened to the second base plate 405, and the heating plate 401 is placed on the inner wall of the insulating bearing 406. The insulating bearing 406 is fitted over the tail end of the test copper rod 404. The test copper rod 404 is inserted into the second fixed base 403 until the end surface contacts. Then, screws are used to lock the matching circumferential surface. The circumferential surface of the insulating bearing 406 is provided with an arc groove. The relative position of the insulating bearing 406 and the second fixed base 403 is locked by tightening screws. Finally, the second fixed base 403 is installed on the second base plate 405. It is important to lead the circuit of the heating plate 401 out of the gap to avoid damaging the circuit. The purpose of using the insulating bearing 406 is to retain more heat transferred by the heating plate 401 to the test copper rod 404 and reduce the heat generated by the heating plate 401 from being dissipated during the transfer process. The three second linear bearings 402 fixed on the second base plate 405 can ensure that the second base plate 405 always moves along the direction of the fixed seat guide axis 602. Figure 1 The heat dissipation end assembly 1 shown has the same displacement direction, so simply ensuring that the end face of the test copper rod 404 is perpendicular to its movement direction can ensure that the contact end faces of the two copper rods are parallel. When the contact end faces are parallel, the pressure between the contact surfaces can be evenly distributed when under pressure, and the evenly distributed pressure can make the thickness of the indium gallium solution film between the interlayers consistent. Figure 3 The first base plate 101 shown is processed in an integrated manner, and the fixing hole of the second linear bearing 402 is processed in one process. The advantage is that the deviation of the corresponding hole positions of the second base plate 405 and the first base plate 101 can be eliminated, and the parallelism between the second base plate 405 and the first base plate 101 can be ensured. Then, the second base plate 405 is separated from the first base plate 101 by wire cutting. Secondly, the second fixed base 403 and the first fixed base 103 are processed by a lathe, which can improve the verticality accuracy between the axis and the fixed end face. The heat dissipation end copper rod 104 and the test copper rod 404 are both made of pure copper. Pure copper has good thermal conductivity and can accurately detect the heat transferred from the heating end in real time. In order to prevent liquid metal from corroding the copper rod, it is necessary to nickel-plate the surface with a nickel layer thickness of 30um. Since the experimental temperature is lower than 150°C, taking into account the comprehensive considerations of mechanical properties, thermal insulation properties and corrosion resistance, the second base plate 405, the second fixed base 403, the first fixed base 103 and the first base plate 101 can be made of PEEK polyetheretherketone material to allow heat to be transferred as far as possible between the test copper rod 404 and the heat dissipation end copper rod 104.

[0029] In some embodiments, the motion control component 2 includes: Figure 4The shown box bottom plate 201, motor protection cover plate 202, motor support seat 203 and ball screw actuator 204, the motor support seat 203 is connected on the box bottom plate 201, the ball screw actuator 204 is installed on the motor support seat 203, and the screw rod of the ball screw actuator 204 is connected with the transmission assembly 5 outside the motor support seat 203, the motor protection cover plate 202 is arranged between the motor of the ball screw actuator 204 and the opposite contact surface, and the motor protection cover plate 202 is provided with a groove for collecting the liquid metal.

[0030] The motor support seat 203 includes a rib plate and a support plate, the support plate is connected on the box bottom plate, and the rib plate is arranged between the support plate and the box bottom plate; the side of the motor of the ball screw actuator 204 is provided with a motor protection side plate 205.

[0031] The ball screw actuator 204 is a commonly used linear drive module, the friction between the ball and the screw rod is small, the linear movement precision is high, the motor can be selected as a stepping motor, the rib plate can effectively reduce the deformation of the motor support plate caused by the motor driving force, the motor support seat 203 is directly fastened on the box bottom plate 201 by screws, and the overall device weight can be reduced. The ball screw actuator 204 is characterized in that the stepping motor and the ball screw are integrated into a special design mechanism, which reduces the space occupied by the device, the screw rod shaft passes through the motor support seat 203, the stepping motor is fastened on the motor support seat 203 by four screws, under the driving of the stepping motor, the screw rod shaft can move forward and backward. Since the liquid metal has a corrosive effect on copper and aluminum, the ball screw actuator 204 is located below the test end surface, in order to prevent the liquid metal from corroding, the motor protection cover plate 202 and the motor protection side plate 205 are designed around the motor to isolate the liquid metal from contacting the motor, and a groove is designed on the motor protection cover plate 202 for collecting the liquid metal.

[0032] In some embodiments, the transmission assembly 5 includes as Figure 7The shown gland 501, H-shaped connecting shaft 502, transmission base 503, third linear bearing 504, screw connecting seat 505 and linkage seat 506, the screw connecting seat 505 is screwed with the screw of the ball screw actuator 204, one side of the screw of the ball screw actuator 204 is provided with the third linear bearing 504, the inner ring of the third linear bearing 504 is guided and connected with the support guide assembly 6, the outer ring of the third linear bearing 504 is connected with the screw connecting seat 505, the linkage seat 506 is connected with the screw connecting seat 505 and is located above the outer ring of the screw of the ball screw actuator 204 and the third linear bearing 504, one side of the H-shaped connecting shaft 502 is arranged on the end of the linkage seat 506 away from the screw connecting seat 505, the gland 501 is pressed on the H-shaped connecting shaft 502, one side of the H-shaped connecting shaft 502 is pressed on the linkage seat 506 through the gland 501, the other side of the H-shaped connecting shaft 502 is connected with one side of the transmission base 503, the transmission base 503 is rotationally connected with the linkage seat 506 through the H-shaped connecting shaft 502, the other side of the transmission base 503 is connected with the second bottom plate 405 away from one side of the second fixed base 403.

[0033] The traditional design places the motor shaft on the side of the device, and due to the length of the screw shaft and the motor, the entire device is very long, occupies experimental space, and brings challenges to the vacuum experimental environment, so in order to reduce the overall size of the device, referring to Figure 2 The motor of the ball screw actuator 204 is placed below the entire device, which also brings a series of difficulties, the most important of which is how to convert the thrust output by the ball screw actuator 204 into thrust in the direction of the axis of the test copper rod 404. There is a small relative contact surface between the second linear bearing 402 and the fixed seat guide shaft 602, the thrust direction of the transmission assembly 5 affects the coincidence of the axis of the test copper rod 404 and the movement direction of the driving end assembly 4, if the directions are different, the contact pressure between the two copper rods will be uneven, causing the film thickness of the liquid metal between the interfaces to be different. If the transmission assembly 5 uses a connecting rod to directly connect the second bottom plate 405, the connecting rod will deform due to tension, and the second bottom plate 405 will also deflect due to the deformation of the connecting rod, causing the axis of the test copper rod 404 to not coincide with the movement direction of the driving end assembly 4. Therefore, the solution in the present application is to decouple the deformation of the transmission assembly 5 in force transmission by using two groups of rolling bearings 5024, as follows. When the ball screw actuator 204 is working, the screw nut rotates inside the motor and the screw shaft moves linearly, the end of the screw shaft can be an M8 external thread, which can be screwed with the screw connecting seat 505, the screw connecting seat 505 fixes two third linear bearings 504, two screw connecting seats 505 are fixed with the linkage seat 506, four third linear bearings 504 are installed on the two H-shaped connecting shafts 502, the H-shaped connecting shafts 502 are connected with the transmission base 503 through the linkage seat 506, and the other side of the transmission base 503 is connected with the second bottom plate 405 away from the second fixed base 403. Figure 9The shown lead screw guide shaft 601 can ensure that the linkage seat 506 always moves along the direction of the lead screw guide shaft 601. The upper part of the linkage seat 506 is pressed by the gland 501 against one end of the H-shaped connecting shaft 502, and the other end of the H-shaped connecting shaft 502 can be pressed by another gland 501 against the transmission base 503. The function of the H-shaped connecting shaft 502 is that when the linkage seat 506 is deformed under force, the H-shaped connecting shaft 502 will rotate, and the pushing force exerted by the H-shaped connecting shaft 502 on the transmission base 503 is along the direction of the shaft 5021. Since the H-shaped connecting shaft 502 and the transmission base 503 are in line contact, the transmission base 503 will not be deflected in posture. The second bottom plate 405 is fixedly connected with the transmission base 503, and the second linear bearing 402 limits the second bottom plate 405 to move only along the direction of the fixed seat guide shaft 602. The friction between the second linear bearing 402 and the fixed seat guide shaft 602 can be ignored, so the axis of the test copper bar 404 is along the direction of the fixed seat guide shaft 602.

[0034] In some embodiments, the H-shaped connecting shaft 502 comprises a shaft 5021, a rotating shaft 5022, a locking nut 5023, a rolling bearing 5024, and a disc spring 5025, as shown in the figure. Figure 8 The shaft 5021 is at least two, one end of the shaft 5021 is sequentially connected with the locking nut 5023 through the rolling bearing 5024 and the disc spring 5025, the middle part of the two shafts 5021 is rotatably connected in the rotating shaft 5022 through the rolling bearing 5024, the middle part of the two shafts 5021 is connected with the rotating shaft 5022 in H shape through the bearing, and the other end of the shaft 5021 is provided with a shaft shoulder, the shaft shoulder is locked with the inner ring of the rolling bearing 5024 through the locking nut 5023 and the disc spring 5025, the shaft shoulder and the locking nut 5023 of one of the shafts 5021 are pressed on the linkage seat 506 by the gland 501, and the shaft shoulder and the locking nut 5023 of the other shaft 5021 are pressed on the transmission base 503.

[0035] During installation, since the two ends of the H-shaped connecting shaft 502 are completely the same, only one end is introduced here. First, the disc spring 5025 and the rolling bearing 5024 are sequentially inserted into the shaft 5021, and the convex side is tightly attached to the inner ring of the rolling bearing 5024. Then, the outer ring of the rolling bearing is matched with the boss inside the rotating shaft 5022 by passing through the rotating shaft 5022. The other side corresponds to the installation of the rolling bearing 5024 and the disc spring 5025, and finally the locking nut 5023 is locked.

[0036] In some embodiments, the support and guide assembly 6 comprises a shaft 5021, a rotating shaft 5022, a locking nut 5023, a rolling bearing 5024, and a disc spring 5025, as shown in the figure. Figure 9The screw guide shaft 601, the fixed seat guide shaft 602, the box side plate 603, the guide shaft positioning plate 604 and the top block 605 are shown. The box side plate 603 is set on one side of the guide shaft positioning plate 604. The guide shaft positioning plate 604 and the box side plate 603 are both connected to the box bottom plate 201. The fixed seat guide shaft 602 is connected between the two guide shaft positioning plates 604 and guides the sliding direction of the active end assembly 4 and the heat dissipation end assembly 1 by slidingly connecting with the inner ring of the second linear bearing 402 and the first linear bearing 105. The screw guide shaft 60 1 is connected between the guide shaft positioning plate 604 and the motor support seat 203, and guides the sliding direction of the transmission assembly 5 by slidingly connecting with the inner ring of the third linear bearing 504. The screw guide shaft 601 and the fixed seat guide shaft 602 are parallel to each other, and the ends of the screw guide shaft 601 and the fixed seat guide shaft 602 are limited on the guide shaft positioning plate 604 and the motor support seat 203 by the top block 605; the support guide assembly 6 also includes a handle 9, which is arranged on the outside of the box side plate 603, and the support guide assembly 6 is transported by the handle 9.

[0037] During installation, two lead screw guide shafts 601 and three fixed seat guide shafts 602 can be used. The two guide shaft positioning plates 604 are punched in one piece and then divided by wire cutting. The fixed seat guide shaft 602 is installed by using a conical surface positioning and a top block 605 to tighten it, ensuring the position of the fixed seat guide shaft 602 and the parallelism between the fixed seat guide shafts 602.

[0038] In some embodiments, the grating assembly 3 includes: Figure 5 The grating scale 301, origin selector 302, reading head 303, and reading head mounting bracket 304 are shown. The reading head 303 is connected to the reading head mounting bracket 304, and the reading head mounting bracket 304 is connected to the active end component 4. The grating scale 301 and origin selector 302 are both arranged on one side of the reading head 303. The grating scale 301 and the active end component 4 slide relatively parallel to each other. The grating scale 301 is used to measure the sliding distance of the reading head 303, and the origin selector 302 is used to calibrate the starting position of the reading head 303. The reading head 303 can be tightened by adjusting the bolts on the reading head mounting bracket 304 to adjust the position and ensure the signal reading strength of the reading head 303. The reading head mounting bracket 304 is fixed on the second base plate 405. The grating scale 301 and the origin selector 302 are attached to the base plate 405. Figure 9 On the side panel 603 of the box, an origin selector 302 is shown to correct the zero position. The brand can use the Renishaw incremental encoder series, with a resolution of up to 0.1µm. Position feedback precisely controls the stepper motor drive, thereby indirectly controlling the contact pressure between the test copper rods 404.

[0039] In some embodiments, the liquid metal contact thermal resistance measuring device further comprises Figure 1 A limit switch assembly 7 is arranged in the sliding direction of the driving end assembly 4 to limit the sliding end position of the driving end assembly 4. When the driving end assembly 4 contacts the limit switch assembly 7 during sliding, the limit switch assembly 7 can feed a signal to the motor in the ball screw actuator 204 to control the movement stroke of the motor, so as to prevent the driving end assembly 4 from moving out of position and damaging the device. Figure 4

[0040] In specific use, the limit switch assembly 7 can be composed of an Omron contact switch D5A and a fixing plate thereof. The limit switch assembly 7 is arranged on both sides of the second bottom plate 405. When the second bottom plate 405 moves to the limit position and triggers the switch, the motor stops moving at this time. Therefore, the limit switch can control the movement stroke of the motor to ensure the safety of the device. Figure 6

[0041] Because the thickness of the liquid metal and the pressure have a one-to-one corresponding relationship, the closed-loop control motor and the pressure sensor 107 accurately feedback the motor output torque to ensure the pressure between the test copper rod 404 and the contact surface of the heat dissipation end copper rod 104. In order to control the thickness of the test liquid metal film, only the output torque needs to be controlled. The limit switch effectively limits the movement stroke of the motor, which can protect the entire device from being damaged by moving out of position.

[0042] The heating sheet 401 is arranged inside the heat insulation bushing 406. The heat insulation bushing 406 can be made of heat insulation ceramic material, which can effectively reduce heat loss. At the same time, the second fixed base 403 and the second bottom plate 405 are made of PEEK polyether ether ketone material. This material can not only play a heat insulation role, but also has good mechanical properties, which can well transmit the thrust generated by the motor. Finally, the PEEK polyether ether ketone material has the chemical property of preventing liquid metal corrosion. In order to accurately measure the heat transferred from the heating end to the heat dissipation end copper rod 104, a water cooling device is used at the bottom to real-time discharge the heat that interferes with the experimental data.

[0043] Three linear bearings and a fixed seat guide shaft 602 are used to limit the movement direction of the second bottom plate 405 and the first bottom plate 101, reduce the influence of stress deformation of the transmission assembly 5 on the attitude yaw of the second bottom plate 405, and make the contact surface in parallel state during movement, that is, to ensure that the contact end surface of the test copper rod 404 and the heat dissipation end copper rod 104 is parallel.

[0044] ​​The two sets of rolling bearings 5024 and the rotating shaft 5022 can change the connection between the transmission assembly 5 and the second bottom plate 405 from surface connection to linear contact. When the transmission assembly 5 is deformed under force, the rotating shaft 5022 changes in angle, and the linear contact under force does not cause the attitude of the contact surface to deviate, so the transmission assembly 5 can effectively compensate for the deformation amount under force.

[0045] The second bottom plate 405 and the first bottom plate 101, and the two guide shaft positioning plates 604 are processed by one-body punching and linear cutting, which ensures the position degree, parallelism of the three fixed seat guide shafts 602, and the parallelism between the second bottom plate 405 and the first bottom plate 101. The lathe processing is used for the second fixed seat 403 and the first fixed seat 103, which ensures the perpendicularity between the mounting hole and the end face.

[0046] The fixed seat guide shaft 602 is positioned by adopting the form of a conical surface and a top block 605, which further improves the position degree of the fixed seat guide shaft 602.

[0047] The two lead screw guide shafts 601 provide guidance and support for the transmission assembly 5, and effectively transmit the thrust generated by the motor to the test copper bar 404.

[0048] It should be noted that the terms "first", "second", and the like in the present application are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein.

[0049] In the description of the present application, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A device for measuring contact thermal resistance of liquid metal, characterized in that: The invention comprises a heat dissipation end component (1), a motion control component (2), a grating component (3), an active end component (4), a transmission component (5), a support guide component (6) and a temperature sensor (8), wherein a relative contact surface is provided between the heat dissipation end component (1) and the active end component (4), the relative contact surface is used to clamp the liquid metal coated between the relative contact surfaces, the active end component (4) is used to heat the liquid metal in the relative contact surface, the heat dissipation end component (1) is used to measure the thermal conductivity of the liquid metal in the relative contact surface, the heat dissipation end component (1) is connected to one end of the support guide component (6), the active end component (4) is slidably arranged relative to the heat dissipation end component (1), and the heat dissipation end component (1) is connected to the support guide component (6). The component (1) and the active end component (4) are both connected to the temperature sensor (8) on one side close to the relative contact surface. The heat dissipation end component (1) and the active end component (4) measure the temperature at the point where the temperature sensor (8) is installed through the temperature sensor (8). One end of the transmission component (5) is connected to the active end component (4), and the other end of the transmission component (5) is connected to the motion control component (2). The motion control component (2) controls the relative sliding distance between the active end component (4) and the heat dissipation end component (1) through the transmission component (5). The grating component (3) is connected to the active end component (4), and the grating component (3) is used to detect the relative sliding distance.

2. The device for measuring contact thermal resistance of liquid metal according to claim 1, characterized in that: The heat dissipation end assembly (1) comprises a first base plate (101), a water-cooled copper tube (102), a first fixed seat (103), a heat dissipation end copper rod (104), a first linear bearing (105), a cooling copper plate (106) and a pressure sensor (107), wherein the inner ring of the first linear bearing (105) is connected to the support guide assembly (6), the first base plate (101) is connected to the outer ring of the first linear bearing (105), the pressure sensor (107) is connected between the first base plate (101) and the support guide assembly (6), and the pressure sensor (107) is located on the side of the first base plate (101) away from the active end assembly (4), and the cooling copper plate (106) is connected to the support guide assembly (6). The plate (106) is connected to the side of the first base plate (101) away from the pressure sensor (107), the first fixing seat (103) is connected to the side of the cooling copper plate (106) away from the first base plate (101), one end of the heat dissipation end copper rod (104) forms the relative contact surface with the active end component (4), the other end of the heat dissipation end copper rod (104) passes through the first fixing seat (103) and is connected to the cooling copper plate (106), the water-cooled copper tube (102) conducts heat to the heat dissipation end copper rod (104) through the cooling copper plate (106), and a point for mounting the temperature sensor (8) is provided at one end of the heat dissipation end copper rod (104) close to the active end component (4).

3. The device for measuring contact thermal resistance of liquid metal according to claim 2, characterized in that: The active end assembly (4) includes a heating plate (401), a second linear bearing (402), a second fixed base (403), a test copper rod (404), a second base plate (405) and a heat-insulating bearing (406), the inner ring of the second linear bearing (402) is connected to the support guide assembly (6), the second base plate (405) is connected to the outer ring of the second linear bearing (402), one end of the test copper rod (404) is arranged opposite to one end of the heat dissipation end copper rod (104), and The relative contact surface is formed at the opposite end, the other end of the test copper rod (404) is inserted into the second fixed base (403), the second fixed base (403) is connected to the second bottom plate (405), and is located on one side of the second linear bearing (402), the heating plate (401) is inserted into the second fixed base (403) and connected to the other end of the test copper rod (404), and the heat-insulating bearing (406) is connected between the heating plate (401) and the second fixed base (403) and is used to insulate the two.

4. The device for measuring contact thermal resistance of liquid metal according to claim 3, characterized in that: The motion control assembly (2) comprises a box bottom plate (201), a motor protection cover plate (202), a motor support seat (203) and a ball screw actuator (204), wherein the motor support seat (203) is connected to the box bottom plate (201), the ball screw actuator (204) is mounted on the motor support seat (203), and the screw of the ball screw actuator (204) extends out of the motor support seat (203) and is connected to the transmission assembly (5), the motor protection cover plate (202) is arranged between the motor of the ball screw actuator (204) and the relative contact surface, and a groove for collecting dripping liquid metal is provided on the motor protection cover plate (202).

5. The device for measuring contact thermal resistance of liquid metal according to claim 4, characterized in that: The motor support seat (203) comprises a rib plate and a support plate, the support plate is connected to the box bottom plate (201), and the rib plate is arranged between the support plate and the box bottom plate (201); a motor protection side plate (205) is provided on the side of the motor of the ball screw actuator (204).

6. The device for measuring contact thermal resistance of liquid metal according to claim 4, characterized in that: The transmission assembly (5) comprises a gland (501), an H-shaped connecting shaft (502), a transmission base (503), a third linear bearing (504), a screw connection seat (505) and a linkage seat (506), wherein the screw connection seat (505) is threadedly connected to the screw of the ball screw actuator (204), a third linear bearing (504) is provided on one side of the screw of the ball screw actuator (204), an inner ring of the third linear bearing (504) is guide-connected to the support guide assembly (6), an outer ring of the third linear bearing (504) is connected to the screw connection seat (505), and the linkage seat (506) is connected to the screw connection seat (505) and is located on the third linear bearing (50 4) and above the outer ring of the ball screw actuator (204), one side of the H-shaped connecting shaft (502) is arranged on the end of the linkage seat (506) away from the screw connecting seat (505), the pressure cover (501) is pressed on the H-shaped connecting shaft (502), one side of the H-shaped connecting shaft (502) is pressed on the linkage seat (506) through the pressure cover (501), the other side of the H-shaped connecting shaft (502) is connected to one side of the transmission base (503), the transmission base (503) is rotatably connected to the linkage seat (506) through the H-shaped connecting shaft (502), and the other side of the transmission base (503) is connected to the side of the second base plate (405) away from the second fixed base (403).

7. The device for measuring contact thermal resistance of liquid metal according to claim 6, characterized in that: The H-shaped connecting shaft (502) comprises a shaft (5021), a rotating shaft (5022), a locking nut (5023), a rolling bearing (5024) and a disc spring (5025). There are at least two shafts (5021). One end of the shaft (5021) passes through the rolling bearing (5024) and the disc spring (5025) in sequence and is connected to the locking nut (5023). The middle parts of the two shafts (5021) are rotatably connected to the rotating shaft (5022) through the rolling bearing (5024). The two shafts (5021) are connected to the rotating shaft (5022) through the rolling bearing (5024). The middle part of the rod (5021) is connected to the rotating shaft (5022) through a bearing to form an H shape, and the other end of the shaft rod (5021) is provided with a shaft shoulder, which is locked with the inner ring of the rolling bearing (5024) through a locking nut (5023) and a disc spring (5025). The shaft shoulder and the locking nut (5023) of one shaft rod (5021) are pressed onto the linkage seat (506) through a pressure cover (501), and the shaft shoulder and the locking nut (5023) of the other shaft rod (5021) are pressed onto the transmission base (503).

8. The device for measuring contact thermal resistance of liquid metal according to claim 6, characterized in that: The support guide assembly (6) includes a screw guide shaft (601), a fixed seat guide shaft (602), a box side plate (603), a guide shaft positioning plate (604) and a top block (605), wherein the box side plate (603) is arranged on one side of the guide shaft positioning plate (604), and the guide shaft positioning plate (604) and the box side plate (603) are both connected to the box bottom plate (201), and the fixed seat guide shaft (602) is connected between the two guide shaft positioning plates (604) and guides the sliding direction of the active end assembly (4) and the heat dissipation end assembly (1) by slidingly connecting with the inner ring of the second linear bearing (402) and the first linear bearing (105). The guide shaft (601) is connected between the guide shaft positioning plate (604) and the motor support seat (203), and guides the sliding direction of the transmission assembly (5) by slidingly connecting with the inner ring of the third linear bearing (504). The lead screw guide shaft (601) and the fixed seat guide shaft (602) are parallel to each other, and the ends of the lead screw guide shaft (601) and the fixed seat guide shaft (602) are limited on the guide shaft positioning plate (604) and the motor support seat (203) by the top block (605); the support guide assembly (6) also includes a handle (9), which is arranged on the outside of the box side plate (603), and the support guide assembly (6) is transported by the handle (9).

9. The device for measuring contact thermal resistance of liquid metal according to claim 1, characterized in that: The grating assembly (3) comprises a grating ruler (301), an origin selector (302), a reading head (303), and a reading head mounting frame (304); the reading head (303) is connected to the reading head mounting frame (304); the reading head mounting frame (304) is connected to the active end assembly (4); the grating ruler (301) and the origin selector (302) are both arranged on one side of the reading head (303); the grating ruler (301) and the active end assembly (4) slide relatively parallel to each other; and the grating ruler (301) is used to measure the sliding distance of the reading head (303); the origin selector (302) is used to calibrate the starting position of the reading head (303) to zero.

10. The device for measuring contact thermal resistance of liquid metal according to claim 1, characterized in that: It also includes a limit switch assembly (7), which is arranged in the sliding direction of the active end assembly (4) and is used to limit the sliding end position of the active end assembly (4).

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