A pressure controllable bonding clamp and method of use thereof

Abstract

The present application relates to a pressure-controllable bonding clamp, comprising a substrate, two ends of which are respectively provided with a first end cover and a second end cover; a clamping assembly arranged between the first end cover and the second end cover and used for clamping a bonding object, comprising a first pressure head and a second pressure head, opposite surfaces of the first pressure head and the second pressure head can fix the bonding object; and an elastic member arranged between the first pressure head and the first end cover; a screw rod assembly used for controlling the position of the second pressure head, comprising a screw rod penetrating through the second end cover and being in contact connection with the second pressure head, a screw rod sleeve in screw connection with the screw rod, and the screw rod sleeve being fixedly connected with the second end cover; the rotating screw rod pushes and limits the relative position of the second pressure head and the second end cover, controls the compression amount of the elastic member, and further controls the pressure size of the elastic member applied to the first pressure head, so as to change the pressure between the first pressure head and the second pressure head. The bonding clamp provided by the present application has a compact structure, is convenient to process, and is low in cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated circuit bonding experiments, in particular to a pressure-controllable bonding clamp and a method thereof. BACKGROUND

[0002] At present, with the rapid development of information technology, the Internet of Things based on 5G technology has begun to enter the commercial stage, and the public demand for consumer electronic products is increasing, and the integration of electronic products is becoming increasingly stringent. It is difficult to significantly reduce the integration of products by relying only on the improvement and innovation of integrated circuit device structure. Today, integrated circuit products have gradually entered the technology node of 7nm or less, and Moore's law is about to end. In the future, three-dimensional integration will be the most important track. Three-dimensional integration is an advanced packaging integration technology that includes Cu-Cu metal-metal bonding, Si-Si bonding, SiO2-SiO2 bonding, and heterogeneous mixed bonding processes. In the process of studying the bonding mechanism of different materials, batch bonding experiments with stable process parameters are needed to verify the feasibility of the bonding scheme and the selected materials. Therefore, it is particularly important to stably realize batch bonding experiments under multiple conditions.

[0003] There are many ways to realize material bonding, such as surface activation bonding with the help of Ar plasma, bonding by chemical reagent treatment to passivate the Cu surface, using special processes to grow preferentially oriented Cu on the sample surface to promote bonding, and hot-press bonding with a surface metal passivation layer. Among them, hot-press bonding shows better stability and process compatibility.

[0004] For hot-press bonding, large machines are often used for experiments, which have high energy consumption and cost, and are not suitable for low-cost experiments and verification. Existing small bonding clamps have complex structures, are not suitable for batch processing, or cannot fix samples of multiple sizes, and have problems such as displacement before bonding, or difficulty in effectively cleaning the surface of the sample before bonding. Therefore, there is an urgent need for a small clamp that is stable and reliable, compact in structure, convenient for bonding experiments of samples of multiple sizes, and ensures the cleanliness of the sample surface before bonding, so that the sample can complete the annealing bonding process in the heating device. SUMMARY

[0005] To achieve the above purpose and reduce the cost of bonding experiments, the present application provides a pressure-controllable bonding clamp, comprising: a substrate, both ends of which are respectively provided with a first end cover and a second end cover;

[0006] The clamping assembly is arranged between the first end cover and the second end cover and is used for clamping the bonding object, and the clamping assembly comprises a first pressing head part and a second pressing head part which are in sliding connection with the substrate, and opposite surfaces of the first pressing head part and the second pressing head part are fixed with the bonding object; and an elastic member is arranged between the first pressing head part and the first end cover, and the elastic member applies force to the first pressing head part;

[0007] The screw rod assembly is used for controlling the position of the second pressing head part and comprises a screw rod which penetrates through the second end cover and is in contact connection with the second pressing head part, and a screw rod sleeve which is in threaded connection with the screw rod and is fixedly connected with the second end cover;

[0008] The rotating screw rod pushes and limits the second pressing head part, the compression amount of the elastic member between the first pressing head part and the first end cover is limited by pushing the second pressing head part, so that the pressure applied by the elastic member to the first pressing head part is controlled, and then the pressure received by the bonding object fixed between the first pressing head part and the second pressing head part is changed.

[0009] Further, a guide groove is formed in the substrate.

[0010] Further, the bottom of the first end cover and the second end cover is provided with a protruding part matched with the guide groove, and the protruding part is embedded in the guide groove.

[0011] Further, the first pressing head part and the second pressing head part are located in the guide groove and are in sliding connection with the guide groove.

[0012] Further, the inside of the first pressing head part and the second pressing head part is provided with an air path, and each air path has two air holes, one of which is used for connecting a vacuum pump, and the other of which is located on the opposite surface of the first pressing head part and the second pressing head part and is covered by the bonding object, and the bonding object is adsorbed by the negative pressure provided by the vacuum pump.

[0013] Further, the first pressing head part is further connected with a rod member penetrating through the first end cover, and the first end cover is provided with a locking pin for locking the position of the rod member.

[0014] Further, the elastic member is a high-temperature-resistant spring which is penetrated outside the rod member.

[0015] Further, the screw rod assembly is a trapezoidal screw rod and has a self-locking function.

[0016] In summary, the pressure-controllable bonding clamp provided by the present application has the following beneficial effects:

[0017] The structure is compact, the cost is low, and the bonding clamp is resistant to high temperature; according to the space size of the heating device, a plurality of bonding clamps can be placed at one time to realize batch hot-press bonding experiments.

[0018] The present application also provides a pressure-controllable bonding clamp using method, which is realized by using the above bonding clamp and comprises the following steps:

[0019] According to the bonding pressure requirements, the first pressure head is pushed to change the distance between it and the first end cap, thus compressing the elastic element;

[0020] Use the locking pin to temporarily lock the position of the first pressure head and keep the elastic element compressed.

[0021] Each bonded compound is fixed to the opposing surfaces of the first and second pressure heads;

[0022] The rotating screw pushes the second pressure head toward the first pressure head until the bonds fixed to the first and second pressure heads are in place;

[0023] Release the locking state of the first pressure head and use the elastic force of the elastic element to press the bonds together.

[0024] In summary, the pressure-controllable bonding fixture provided by this invention enables batch experiments under controllable bonding pressure, bonding temperature, bonding time, and bonding atmosphere. The bonded compound structure and dimensions are flexible, the bonding fixture has a compact structure, is easy to manufacture, and is inexpensive. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the bonding fixture structure of the present invention;

[0026] Figure 2 These are three views of the substrate of the present invention: 2a is the front view, 2b is the side view, and 2c is the top view.

[0027] Figure 3 The first end cap of the present invention is shown in three views: 3a is the front view, 3b is the side view, and 3c is the top view.

[0028] Figure 4 The following are three views of the second end cap of the present invention: 4a is the front view, 4b is the side view, and 4c is the top view.

[0029] Figure 5 This is a schematic diagram of the lead screw assembly structure of the present invention;

[0030] Figure 6 The first pressing head of the present invention is shown in three views: 6a is the front view, 6b is the side view, and 6c is the top view.

[0031] Figure 7 The second pressure head of the present invention is shown in three views: 7a is the front view, 7b is the side view, and 7c is the top view.

[0032] Figure 8 This is a schematic diagram of the elastic element of the present invention;

[0033] Figure 9 This is a bonding structure diagram of the compound used in Experiment 2 of this invention;

[0034] Figure 10 SAM test results of the bonded compounds in Experiment 1;

[0035] Figure 11 TEM test results of the bonded compounds in Experiment 1;

[0036] Figure 12 Electrical test results of the Kelvin four-wire detection method in Experiment 2. Detailed Implementation

[0037] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the pressure-controllable bonding fixture and its usage method proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0038] like Figure 1 As shown, the present invention provides a pressure-controllable bonding jig, comprising: a substrate 1, with a first end cap 2 and a second end cap 3 respectively at its two ends; a clamping assembly disposed between the first end cap 2 and the second end cap 3 for clamping a bonding compound, the clamping assembly including a first pressing head 5 and a second pressing head 6 slidably connected to the substrate 1, wherein the bonding compound can be fixed on the opposing surfaces of the first pressing head 5 and the second pressing head 6; and an elastic member 4, wherein the first pressing head 5 and the first end cap 2 are connected by the elastic member 4, and in use, the elastic member 4 is in a compressed state, thereby applying pressure to the first pressing head 5, causing the first pressing head 5 and the second pressing head 6 to fit together, clamping the bonding compound fixed on them respectively; and a lead screw assembly for adjusting the position of the second pressing head 6, comprising a lead screw 7 and a lead screw sleeve 10 threadedly connected to the lead screw 7, the lead screw sleeve 10 being fixedly connected to the second end cap 3, and the lead screw 7 passing through the lead screw sleeve 10 and the second end cap 3 to contact and connect with the second pressing head 6. Figure 4 , 5As shown, the second end cover 3 has an axial through hole 31 for the lead screw 7 to pass through. One end of the lead screw 7 passing through the through hole 31 contacts the second pressure head 6. The lead screw sleeve 10 has an annular flange 101 circumferentially provided. The flange 101 is provided with a screw hole 102. A screw is screwed into the threaded hole 33 on the second end cover 3 through the screw hole 102 to fix the lead screw sleeve 10 on the second end cover 3.

[0039] Furthermore, the lead screw assembly is a trapezoidal lead screw with a self-locking function. The position of the second pressure head 6 can be adjusted through the lead screw assembly. Specifically, rotating the lead screw 7 causes it to move axially within the through hole 31 of the second end cover 3, pushing the second pressure head 6 connected thereto. Since the thread helix angle of the lead screw assembly is less than the static friction angle, a self-locking effect is generated. Rotating the lead screw 7 pushes the second pressure head 6 to the target position, and stopping the rotation of the lead screw 7 will automatically lock the position. By adjusting the position of the second pressure head 6, the distance between the first pressure head 5 and the first end cover 2 can be controlled, thereby controlling the compression amount of the elastic element 4. The elastic element 4 applies different pressures to the first pressure head 5 under different compression amounts, ultimately changing the pressure between the first pressure head 5 and the second pressure head 6. According to different bonding pressure requirements, the lead screw 7 can be rotated to push the second pressure head 6 to different positions to achieve pressure controllability.

[0040] After clamping the bonded compound using the aforementioned bonding fixture, the fixture is placed in a heating device for experimentation at a preset temperature and annealing time. The heating device can be a quartz tube annealing furnace, oven, muffle furnace, etc. Depending on the sealing degree of the heating device cavity, operations such as vacuuming or introducing protective gas can be performed. Multiple sets of bonding fixtures can be placed according to the space volume of the heating device cavity to achieve batch experiments and improve experimental efficiency.

[0041] Preferably, such as Figure 2 As shown, the substrate 1 serves as a carrier, and a guide groove 12 is provided on it so that each component placed on it can be embedded in the guide groove 12, thereby making it more stable.

[0042] Preferably, such as Figures 2 to 4 As shown, the bottom of both the first end cap 2 and the second end cap 3 is provided with protrusions 24 and 34 that match the guide groove 12, and these protrusions 24 and 34 are located within the guide groove 12. Furthermore, the first end cap 2, the second end cap 3, and the base plate 1 are all fixedly connected by bolts and threaded holes. The base plate 1 has eight threaded holes 11, and the first end cap 2 and the second end cap 3 each have four through holes 22 and 32. The first end cap 2 and the second end cap 3 are all fixedly connected to the base plate 1 by four bolts.

[0043] Preferably, the first pressing head 5 and the second pressing head 6 are both located inside the guide groove 12 and are slidably connected to the guide groove 12.

[0044] Preferably, such as Figure 6 , 7 As shown, both the first pressure head 5 and the second pressure head 6 have internal air passages 51 and 61, each with two air holes. One air hole in each air passage is connected to a vacuum pump (not shown in the figure) via a gas guide tube, while the other air hole is covered by the bonding compounds. When the vacuum pump is started, a negative pressure is generated in this air passage, causing the bonding compounds covering the air holes to be adsorbed onto their respective pressure heads. The air holes covered by the bonding compounds are located on opposite surfaces of the first pressure head 5 and the second pressure head 6. Each air hole connected to the vacuum pump is a threaded hole, and each threaded hole is threadedly connected to a gas guide tube, which is then connected to the vacuum pump.

[0045] Preferably, such as Figure 1 , 3 As shown in Figure 6, to maintain the stability of the first pressure head 5 on the substrate 1 and to temporarily lock the position of the first pressure head 5, a rod 9 is also connected to the first pressure head 5. The first end cap 2 has an axial through hole 21 for the rod 9 to pass through, and the first end cap 2 has a locking pin 8 to lock the position of the rod 9. To facilitate the placement of the bonding compound and to fix the compression of the elastic element, the distance between the first pressure head 5 and the second pressure head 6 needs to be increased when placing the bonding compound. After pushing the first pressure head 5 a certain distance, the rod 9 is locked using the locking pin 8, and the second pressure head 6 is adjusted to fit against the first pressure head 5. Finally, the locking pin 8 is opened to release the first pressure head 5. At this time, the elastic element 4 remains compressed, pressing the bonding compound located between the two pressure heads. In this example, the locking pin 8 can be a fastening bolt threaded to the first end cap 2. The first end cap 2 has a threaded hole 23. The threaded hole 23 is located on the path through which the rod 9 passes. After the fastening bolt 8 is tightened, the end of the fastening bolt contacts and presses against the rod 9, generating friction. This friction fixes the position of the rod 9.

[0046] Preferably, such as Figure 8 As shown, the elastic element 4 is a high-temperature resistant spring that passes through the rod 9. In this example, the operating temperature is below 400°C, and the high-temperature resistant spring can maintain its elasticity at 400°C.

[0047] In summary, the pressure-controllable bonding fixture provided by this invention enables batch experiments under controllable bonding pressure, bonding temperature, bonding time, and bonding atmosphere. The bonded compound structure and dimensions are flexible, the bonding fixture has a compact structure, is easy to manufacture, and is inexpensive.

[0048] The above-described method of using the bonding fixture includes the following steps:

[0049] According to the bonding pressure requirements, the first pressure head 5 is pushed to change the distance between it and the first end cap 2, and the elastic element 4 is compressed. The corresponding distance needs to be calculated according to the elastic coefficient of different elastic elements 4.

[0050] The position of the first pressure head 5 is temporarily fixed to keep the elastic element 4 in a compressed state. In this example, the position of the first pressure head 5 is fixed by locking the rod 9 with the locking pin 8.

[0051] The two parts of the compound to be bonded are fixed on the opposing surfaces of the first pressure head 5 and the second pressure head 6. In this example, the compound is fixed by vacuum adsorption. After the compound is fixed, it can be purged and cleaned with a nitrogen gun.

[0052] The rotating screw 7 pushes the second pressing head 6 toward the first pressing head 5 until the bonds fixed to the first pressing head 5 and the second pressing head 6 are in place.

[0053] Release the first pressure head 5 from its fixed state, and use the elastic force of the elastic element 4 to press each bonded compound together.

[0054] Based on the above steps, the following bonding experiments can be performed.

[0055] Experiment 1:

[0056] The wafer sample with a metal film deposited on its surface to be bonded is cut to a size of 5mm × 5mm and fixed on the pores on the surface of the first pressure head 5 and the second pressure head 6. The sample surface is then purged with a nitrogen gun to remove debris particles generated during sample transfer. The screw 7 of the screw assembly is turned to move the second pressure head 6 to bring the two samples together. The vacuum pump is turned off, the gas guide tube is removed, and the bonding fixture is placed in the quartz tube annealing furnace. The quartz tube annealing furnace mainly includes a temperature controller, a base, an insulated asbestos sleeve, a quartz tube, and a sealing flange assembly. The sample is placed in the annealing furnace, the sealing flange at the end of the quartz tube is installed, and the N2 / H2 (4%) flow rate is set to 5 SLPM (stard liters per minute). After purging for 5 minutes, the flow rate is set to 2 SLPM, and the annealing program is set to 300℃ for 2 hours. Annealing begins.

[0057] After bonding, the sample was tested using a scanning acoustic microscope (SAM), and the results are as follows: Figure 10 As shown, the surface achieves a bonding area of ​​over 99%, and some defects originate from oxide particles that were not removed from the surface. Figure 10 The area enclosed by the white frame represents a 5mm x 5mm sample. The black area in the center indicates good bonding without gaps, while the white spots indicate particulate contamination at the bonding interface. The white lines represent poor bonding caused by particulate impurities along the outer edge of the sample, which can be improved by refining the cutting process. Figure 11The cross-sectional transmission electron microscope (TEM) image of the bonded sample shows no clear interface, indicating that complete bonding has been achieved. This bonding fixture can achieve reliable bonding.

[0058] Experiment 2:

[0059] The wafer samples to be bonded are cut to a size of 10mm × 3mm and fixedly placed on the pores on the surfaces of the first pressure head 5 and the second pressure head 6. One of the samples is rotated 90°, and the two samples are bonded in a cross-shaped manner, with the bonding surface located in the middle of the sample. Figure 9 This is a schematic diagram of the bonding structure. The sample surface was purged with a nitrogen lance to remove debris particles generated during sample transfer. The screw was turned to bring the sample into place, the vacuum pump was turned off, the gas delivery tube was removed, and the bonding fixture was placed in the quartz tube annealing furnace. The sealing flange at the end of the quartz tube was installed, and the N2 / H2 (4%) flow rate was set to 5 SLPM. After purging for 5 minutes, the flow rate was reduced to 2 SLPM, and the annealing program was set to 300℃ for 2 hours. Annealing began.

[0060] After the bonding experiment, electrical tests are performed on a semiconductor electrical tester. The probes contact the four ends of the cross-shaped fork to form an electrical test structure using the Kelvin four-wire detection method, and reliable electrical characterization of the contact resistance of the bonding surface is performed. Figure 12 The electrical test results of the bonded sample in this embodiment show that the contact resistance of the bonding surface of the bonded sample is approximately 5 × 10⁻⁶. -5 Ω·cm 2 The bonding surface resistance is very low, indicating that a complete bond has been achieved. This bonding fixture can achieve reliable bonding.

[0061] In summary, the present invention has the following beneficial effects:

[0062] It has a compact structure, low cost, and high temperature resistance. Depending on the space size of the heating device, multiple bonding fixtures can be placed at one time to realize batch hot-press bonding experiments.

[0063] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A pressure-controllable bonding clamp, characterized by, The utility model relates to a substrate (1) which is provided with a first end cover (2) and a second end cover (3) at both ends respectively, a clamping assembly arranged between the first end cover (2) and the second end cover (3) for clamping a bonding object, the clamping assembly comprising a first pressure head (5) and a second pressure head (6) which are in sliding connection with the substrate (1), the opposite surfaces of the first pressure head (5) and the second pressure head (6) are fixed with the bonding object respectively, and an elastic member (4) arranged between the first pressure head (5) and the first end cover (2) for applying force to the first pressure head (5), a screw rod assembly for controlling the position of the second pressure head (6) comprising a screw rod (7) penetrating through the second end cover (3) and being in contact connection with the second pressure head (6), a screw rod sleeve (10) in screw connection with the screw rod (7), and the screw rod sleeve (10) is fixedly connected with the second end cover (3), the first pressure head (5) is further provided with a rod member (9) penetrating through the first end cover (2), and the first end cover (2) is provided with a locking pin (8) for locking the position of the rod member (9), the screw rod assembly is a trapezoidal screw rod with self-locking function, the rotating screw rod (7) pushes and limits the second pressure head (6), the compression amount of the elastic member (4) between the first pressure head (5) and the first end cover (2) is limited by pushing the second pressure head (6), so as to control the pressure applied by the elastic member (4) to the first pressure head (5), and then the pressure applied to the bonding object fixed between the first pressure head (5) and the second pressure head (6) is changed. A guide groove (12) is arranged on the substrate (1). The bottom of the first end cover (2) and the second end cover (3) is provided with a protruding part matched with the guide groove (12), and the protruding part is embedded in the guide groove (12). The first pressure head (5) and the second pressure head (6) are located in the guide groove (12) and are in sliding connection with the guide groove (12). The first pressure head (5) and the second pressure head (6) are provided with air channels in the inside, each air channel has two air holes, one air hole is used for connecting a vacuum pump, and the other air hole is located on the opposite surface of the first pressure head (5) and the second pressure head (6) and is covered by the bonding object, and each bonding object is adsorbed by the negative pressure provided by the vacuum pump. The elastic member (4) is a spring which is penetrated outside the rod member (9). The utility model relates to a substrate (1) which is provided with a first end cover (2) and a second end cover (3) at both ends respectively, a clamping assembly arranged between the first end cover (2) and the second end cover (3) for clamping a bonding object, the clamping assembly comprising a first pressure head (5) and a second pressure head (6) which are in sliding connection with the substrate (1), the opposite surfaces of the first pressure head (5) and the second pressure head (6) are fixed with the bonding object respectively, and an elastic member (4) arranged between the first pressure head (5) and the first end cover (2) for applying force to the first pressure head (5), a screw rod assembly for controlling the position of the second pressure head (6) comprising a screw rod (7) penetrating through the second end cover (3) and being in contact connection with the second pressure head (6), a screw rod sleeve (10) in screw connection with the screw rod (7), and the screw rod sleeve (10) is fixedly connected with the second end cover (3), the first pressure head (5) is further provided with a rod member (9) penetrating through the first end cover (2), and the first end cover (2) is provided with a locking pin (8) for locking the position of the rod member (9), the screw rod assembly is a trapezoidal screw rod with self-locking function, the rotating screw rod (7) pushes and limits the second pressure head (6), the compression amount of the elastic member (4) between the first pressure head (5) and the first end cover (2) is limited by pushing the second pressure head (6), so as to control the pressure applied by the elastic member (4) to the first pressure head (5), and then the pressure applied to the bonding object fixed between the first pressure head (5) and the second pressure head (6) is changed.

2. The pressure-controllable bonding clamp of claim 1, wherein, A guide groove (12) is arranged on the substrate (1).

3. The pressure-controllable bonding clamp of claim 2, wherein, The bottom of the first end cover (2) and the second end cover (3) is provided with a protruding part matched with the guide groove (12), and the protruding part is embedded in the guide groove (12).

4. The pressure-controllable bonding clamp of claim 2, wherein, The first pressure head (5) and the second pressure head (6) are located in the guide groove (12) and are in sliding connection with the guide groove (12).

5. The pressure-controllable bonding clamp of claim 1, wherein, The first pressure head (5) and the second pressure head (6) are provided with air channels in the inside, each air channel has two air holes, one air hole is used for connecting a vacuum pump, and the other air hole is located on the opposite surface of the first pressure head (5) and the second pressure head (6) and is covered by the bonding object, and each bonding object is adsorbed by the negative pressure provided by the vacuum pump.

6. The pressure-controllable bonding clamp of claim 1, wherein, The elastic member (4) is a spring which is penetrated outside the rod member (9).

7. A method of using a pressure-controllable bonding clamp, implemented by using the bonding clamp according to any one of claims 1 to 6, characterized in that, The utility model relates to a substrate (1) which is provided with a first end cover (2) and a second end cover (3) at both ends respectively, a clamping assembly arranged between the first end cover (2) and the second end cover (3) for clamping a bonding object, the clamping assembly comprising a first pressure head (5) and a second pressure head (6) which are in sliding connection with the substrate (1), the opposite surfaces of the first pressure head (5) and the second pressure head (6) are fixed with the bonding object respectively, and an elastic member (4) arranged between the first pressure head (5) and the first end cover (2) for applying force to the first pressure head (5), a screw rod assembly for controlling the position of the second pressure head (6) comprising a screw rod (7) penetrating through the second end cover (3) and being in contact connection with the second pressure head (6), a screw rod sleeve (10) in screw connection with the screw rod (7), and the screw rod sleeve (10) is fixedly connected with the second end cover (3), the first pressure head (5) is further provided with a rod member (9) penetrating through the first end cover (2), and the first end cover (2) is provided with a locking pin (8) for locking the position of the rod member (9), the screw rod assembly is a trapezoidal screw rod with self-locking function, the rotating screw rod (7) pushes and limits the second pressure head (6), the compression amount of the elastic member (4) between the first pressure head (5) and the first end cover (2) is limited by pushing the second pressure head (6), so as to control the pressure applied by the elastic member (4) to the first pressure head (5), and then the pressure applied to the bonding object fixed between the first pressure head (5) and the second pressure head (6) is changed. ​ ​ ​ ​ ​

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