A clamp for wafer burn-in test

Abstract

The application relates to the technical field of wafer testing, and particularly discloses a clamp for wafer aging test, which comprises a PCB plate, the PCB plate is fixedly arranged below an upper cover plate, a fixer is used for fixing a probe card below the PCB plate, the PCB plate cover is arranged above the lower cover plate, and the fixer and the probe card are both located in a test cavity; the inner ring of the fixer is radially protruded inward to form an annular bearing platform, a plurality of positioning columns are arranged in an array on the surface of the bearing platform in the circumferential direction, a plurality of positioning holes are arranged on the edge of the probe card in the axial direction, the position of each positioning column corresponds to that of one positioning hole, the positioning column is embedded in the positioning hole, and the side surface of each positioning column is elastically provided with a plurality of elastic resistance columns in the circumferential direction, the end of the resistance column abuts against the inner surface of the positioning hole, and the resistance column can elastically move in the radial direction of the positioning column. The clamp can avoid the problem of poor contact between the probe and the contact caused by the deformation of the probe card in the high-temperature atmosphere during the aging test.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer testing, in particular to a clamp for wafer aging test. BACKGROUND

[0002] With the continuous development of semiconductor manufacturing technology, wafer-level aging test has become an important step to ensure the quality of semiconductor products. In particular, during the wafer aging test process, the design of the clamp is crucial, as it not only needs to accurately fix and support the wafer, but also needs to have the ability to adapt to thermal expansion to ensure accurate contact between the probe and the wafer surface contacts during the test process. Since temperature changes can cause thermal expansion of materials, the fixing method of the probe card and the clamp must be able to effectively address this problem to prevent poor contact caused by uneven expansion, which can affect test results.

[0003] Currently, the common wafer aging test clamp mostly uses the positioning column and positioning slot method to fix the probe card. Although this design can achieve stable positioning of the probe card to some extent, it has the following shortcomings: the expansion of the probe card when heated is usually not uniform, and the traditional positioning column and positioning slot cannot adaptively adjust the position, which may cause local warping and horizontal translation of the probe card. This local warping and translation problem not only affects the positioning accuracy, but also reduces the reliability of the test.

[0004] Therefore, how to provide a clamp design that can adapt to uneven thermal expansion and ensure accurate contact between the probe and the contact during the wafer aging test process has become an important challenge in the current technology. SUMMARY

[0005] Therefore, the present application provides a clamp for wafer aging test that can improve reliability and accuracy.

[0006] The technical solution of the present application is as follows: the present application provides a clamp for wafer aging test, which comprises an upper cover plate, a lower cover plate, a PCB board, a probe card and a fixer. The top of the lower cover plate is provided with a test cavity, the PCB board is fixedly arranged below the upper cover plate, the fixer fixes the probe card below the PCB board, the PCB board is arranged above the lower cover plate, and the fixer and the probe card are both located in the test cavity. It also includes a positioning column. The fixer is annular, the inner ring of the fixer is convex radially inward to form an annular bearing platform, multiple positioning columns are installed on the surface of the bearing platform in a circumferential array, the edge of the probe card is provided with multiple positioning holes in the axial direction, each positioning column corresponds to the position of one positioning hole, the positioning column is embedded in the positioning hole, and the side surface of each positioning column is elastically provided with multiple spring force adjustable abutting columns in the circumferential direction. The end of the abutting column abuts against the inner surface of the positioning hole, and the abutting column can elastically move along the radial direction of the positioning column.

[0007] In the above embodiments, the positioning column is embedded in the positioning hole of the probe card, the diameter of the positioning hole is larger than that of the positioning column, the abutting column protrudes from the side surface of the positioning column, and the positioning column abuts against the inner surface of the positioning hole through the plurality of elastically movable abutting columns to ensure the accurate positioning of the probe card in the horizontal direction. Through the elastic force adjusting structure, the uneven displacement of the probe card caused by thermal expansion in high-temperature testing is dynamically compensated to ensure the stable contact between the probe and the chip contact during testing. The elastic force of the abutting column is set in a manner that can be adjusted, so that the elastic force of the abutting column at the target position can be increased or decreased, thereby allowing the corresponding abutting column to have more or less displacement when dealing with uneven displacement caused by thermal expansion, so that the overall position of the probe card remains stable and large deviation between the probe and the contact is avoided.

[0008] The positioning column, the abutting column and the elastic force adjusting structure are designed in a modular manner, which facilitates disassembly, maintenance and replacement, and improves the service life and maintenance efficiency of the clamp.

[0009] In some embodiments, the positioning column further comprises an elastic force adjusting structure, the inner side of the positioning column is provided with a plurality of accommodating cavities in the circumferential direction, each accommodating cavity is in communication with the side surface of the positioning column through a limiting hole, and an abutting column is embedded in each limiting hole. The abutting column has a larger diameter than the limiting hole at one end located in the accommodating cavity, so that the abutting column can be prevented from being separated from the accommodating cavity. The elastic force adjusting structure is accommodated in the accommodating cavity and elastically drives the abutting column to reciprocate along its own axis in the limiting hole, and the elastic driving force is adjustable.

[0010] In some embodiments, the elastic force adjusting structure comprises an arc-shaped elastic sheet, a cylindrical cam and a driving member. The arc-shaped elastic sheet is arranged in the accommodating cavity, and the convex surface of the arc-shaped elastic sheet abuts against one end of the abutting column close to the accommodating cavity. The arc-shaped elastic sheet abuts against the top of the accommodating cavity at one end in the circumferential direction of the arc surface, and abuts against the circumferential surface of the cylindrical cam at the other end. The driving member is used to drive the cylindrical cam to rotate around the axis.

[0011] In the above embodiments, the arc-shaped elastic sheet and the cylindrical cam are designed in cooperation to ensure the stable and reliable elastic force adjustment process of the abutting column. During the rotation of the cylindrical cam, the arc-shaped elastic sheet can be squeezed to different degrees, and the elastic force of the arc-shaped elastic sheet is changed according to the degree of squeezing, so that the abutting column has different displacement amounts under the same external pressure.

[0012] In some embodiments, the driving member comprises a rotating rod, a limiting disc, a positioning pin and a compression spring, the surface of the positioning column is provided with a shaft hole, a plurality of positioning protrusions are arranged on the surface of the positioning column near one end of the shaft hole in a circumferential direction, a positioning groove is formed between two adjacent positioning protrusions, the rotating rod is coaxially arranged in the shaft hole, the end of the rotating rod near the surface of the positioning column is coaxially fixed with the limiting disc, the surface of the limiting disc is protrusively provided with the positioning pin, the limiting disc and the surface of the positioning column are elastically connected through the compression spring, the compression spring drives the limiting disc to abut against one side of the positioning protrusion near the positioning column, the positioning pin is selectively clamped in one of the positioning grooves, the compression of the compression spring can drive the positioning pin to be separated from the positioning groove, and the rotating rod can rotate relative to the shaft hole after the compression of the compression spring.

[0013] The combination of the rotating rod, the limiting disc, the positioning pin and the compression spring makes the rotation adjustment operation of the cylindrical cam simple and convenient, the user can quickly adjust the elastic force of the abutting column by compressing the compression spring and rotating the rotating rod, after the adjustment is completed, the compression spring is elastically reset by releasing the compression force of the compression spring, and the positioning pin is embedded in the positioning groove again, so that the angle locking of the rotating rod is realized.

[0014] In some embodiments, the positioning column is screw-connected and installed on the surface of the bearing platform.

[0015] In some embodiments, an elastic washer is further arranged between the positioning column and the bearing platform.

[0016] In the above embodiments, the positioning column is screw-connected and installed on the surface of the bearing platform, and the elastic washer is further arranged, so that the stability and vibration resistance of the positioning column are further enhanced. After the elastic washer is arranged, the angle adjustment of the positioning column in the horizontal direction is allowed, and after the angle adjustment, the direction of the supporting column matched with the abutting column can be changed, so that more accurate displacement adjustment effect is realized.

[0017] In some embodiments, a sealing ring is further arranged, and an annular mounting groove is arranged on the upper surface of the lower cover plate in a circumferential direction of the opening of the test cavity, and the sealing ring is embedded in the annular mounting groove.

[0018] In some embodiments, a buffer cavity is arranged on the bottom surface of the upper cover plate, and a ventilation hole is arranged on the surface of the PCB, and the buffer cavity is in communication with the test cavity through the ventilation hole.

[0019] The buffer cavity arranged on the bottom surface of the upper cover plate is in communication with the test cavity, the air pressure in the test cavity is adjusted through the ventilation hole, and the influence of thermal expansion on the clamp structure is reduced. The sealing ring is embedded in the annular mounting groove on the lower cover plate, so that the sealing property of the test cavity is ensured, external pollutants are prevented from entering, and the harsh test environment such as high temperature and high pressure is adapted. The air pressure in the test cavity is adjusted through the ventilation hole, the influence of thermal expansion on the clamp structure is reduced, and the environmental adaptability of the clamp is improved.

[0020] In some embodiments, the buffer cavity has the same diameter as the test cavity.

[0021] The present application has the following beneficial effects relative to the prior art:

[0022] The present application significantly improves the positioning accuracy, reliability, and environmental adaptability of the wafer aging test fixture through the innovative design of the positioning column, the abutting column, and the elastic force adjustment structure. The elastic force adjustment mechanism can effectively compensate for the uneven displacement caused by thermal expansion, ensuring the precise alignment of the probe and the chip contacts. At the same time, the modular design and convenient operation further enhance the practicality and maintenance efficiency of the fixture. This scheme is suitable for harsh test environments such as high temperature and high pressure, and has wide application prospects and promotional value. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0024] Figure 1 is an isometric view of the wafer aging test fixture of the present application;

[0025] Figure 2 is an exploded view of the wafer aging test fixture of the present application;

[0026] Figure 3 is an exploded view of the wafer aging test fixture of the present application from another perspective;

[0027] Figure 4 is a side sectional view of the wafer aging test fixture of the present application;

[0028] Figure 5 is Figure 4 is a partial enlarged view of part A in the figure;

[0029] Figure 6 is an isometric view of the positioning column in the wafer aging test fixture of the present application;

[0030] Figure 7 is an exploded view of the positioning column in the wafer aging test fixture of the present application;

[0031] Figure 8 is a half-sectional isometric view of the positioning column in the wafer aging test fixture of the present application;

[0032] Figure 9 is an isometric view of the driving member in the wafer aging test fixture of the present application.

[0033] In the diagram: 1-Upper cover plate, 2-Lower cover plate, 3-PCB board, 4-Probe card, 5-Fixer, 6-Positioning post, 7-Elastic washer, 10-Sealing ring, 11-Buffer cavity, 21-Test cavity, 22-Annular mounting groove, 41-Positioning hole, 51-Annular bearing platform, 61-Supporting post, 62-Elastic adjustment structure, 621-Arc-shaped spring, 622-Cylindrical cam, 623-Drive component, 6231-Rotating rod, 6232-Limiting plate, 6233-Positioning pin, 6234-Tightening spring, 63-Accommodation cavity, 631-Limiting hole, 64-Shaft hole, 65-Positioning protrusion, 66-Positioning groove. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain. If any definition stated in this section is contrary to or otherwise inconsistent with a definition stated in a patent, patent application, published patent application, or other publication incorporated herein by reference, the definitions listed here shall prevail over those incorporated herein by reference.

[0038] like Figure 1 As shown, combined with Figures 2-9The clamp for wafer aging test of the application comprises an upper cover plate 1, a lower cover plate 2, a PCB plate 3, a probe card 4 and a fixer 5, the top of the lower cover plate 2 is provided with a test cavity 21, the PCB plate 3 is fixedly arranged below the upper cover plate 1, the fixer 5 fixes the probe card 4 below the PCB plate 3, the PCB plate 3 covers the upper cover plate 2 and the fixer 5 and the probe card 4 are both located in the test cavity 21, characterized in that it further comprises a positioning column 6, the fixer 5 is annular, the inner ring of the fixer 5 is radially inwardly convex to form an annular bearing platform 51, a plurality of positioning columns are arranged on the surface of the bearing platform 51 in the circumferential direction, the edge of the probe card 4 is axially provided with a plurality of positioning holes 41, each positioning column 6 corresponds to the position of one positioning hole 41, the positioning column 6 is embedded in the positioning hole 41, and the side surface of each positioning column 6 is elastically provided with a plurality of rebound force adjustable abutting columns 61 in the circumferential direction, the tail end of the abutting column 61 abuts against the inner surface of the positioning hole, and the abutting column 61 can elastically move in the radial direction of the positioning column 6.

[0039] The test cavity 21 provided at the top of the lower cover plate 2 is used for accommodating the probe card 4 and the fixer 5, the upper cover plate 1 and the lower cover plate 2 are connected through a fixing structure (such as a bolt or a buckle) to form a closed test environment, the PCB plate 3 is fixed below the upper cover plate 1, the probe card 4 is fixed below the PCB plate 3 through the fixer 5, the stability of the contact between the probe card 4 and the wafer is ensured, the positioning hole 41 provided at the edge of the probe card 4 corresponds to the positioning column 6 on the bearing platform 51 of the fixer 5 in one-to-one manner, the positioning column 6 is embedded in the positioning hole 41, the accurate alignment of the probe card 4 is realized, the side surface of each positioning column 6 is provided with a plurality of abutting columns 61 in the circumferential direction, the tail end of the abutting column 61 abuts against the inner surface of the positioning hole 41, the stable positioning of the probe card 4 in the horizontal direction is ensured through the elastic force, the rebound force of the abutting column 61 can be adjusted through the elastic force adjusting structure, so that the uneven displacement of the probe card 4 caused by thermal expansion or installation error is dynamically compensated. The annular mounting groove arranged on the upper surface of the lower cover plate 2 is embedded with a sealing ring, so as to ensure the sealing property of the test cavity 21 and prevent external pollutants from entering. The buffer cavity provided at the bottom surface of the upper cover plate 1 is communicated with the test cavity 21 through a vent hole, the air pressure in the test cavity 21 is adjusted, and the influence of thermal expansion on the clamp structure is reduced. The uniform abutting of the multiple abutting columns 61 to the inner surface of the positioning hole 41 ensures the accurate positioning of the probe card 4 in the horizontal direction. Through the elastic force adjusting structure, the uneven displacement of the probe card 4 caused by thermal expansion in the high-temperature test is dynamically compensated, and the stable contact between the probe and the chip contact in the test process is ensured.

[0040] In some embodiments, the positioning column 6 further comprises an elastic force adjusting structure 62, the inner side of the positioning column 6 is provided with a plurality of accommodating cavities 63 in the circumferential direction, each accommodating cavity 63 is in communication with the side of the positioning column 6 through a limiting hole 631, and each limiting hole 631 is embedded with a resisting column 61. The elastic force adjusting structure 62 is accommodated in the accommodating cavity 63, and the elastic force adjusting structure 62 elastically drives the resisting column 61 to reciprocate along its own axis and the elastic force is adjustable.

[0041] In the structural scheme of the above embodiments, the inner side of the positioning column 6 is provided with a plurality of accommodating cavities 63 in the circumferential direction, and each accommodating cavity is in communication with the side of the positioning column 6 through a limiting hole 631. The limiting hole 631 is used for embedding the resisting column 61 and limiting the movement direction (only reciprocating along its own axis). In the high-temperature test, the probe card 4 has a horizontal displacement trend due to thermal expansion. By adjusting the elastic force of the resisting column 61 in different directions, the stress in the displacement direction can be actively offset, so that the probe card 4 can be kept aligned. If the positioning hole 41 and the positioning column 6 are slightly misaligned due to installation deviation of the probe card 4, the elastic support of the resisting column 61 can realize the fine positioning of the probe card 4 by self-adapting the elastic force.

[0042] In some embodiments, the elastic force adjusting structure 62 comprises an arc-shaped elastic sheet 621, a cylindrical cam 622 and a driving member 623, the arc-shaped elastic sheet 621 is arranged in the accommodating cavity 63, and the convex surface of the arc-shaped elastic sheet 621 abuts against one end of the resisting column 61 close to the accommodating cavity 63. The arc-shaped elastic sheet 621 abuts against the top of the accommodating cavity 63 at one end of the circumferential arc surface, and abuts against the circumferential surface of the cylindrical cam 622 at the other end. The driving member 623 can be used to drive the cylindrical cam 622 to rotate around the axis.

[0043] In the above embodiments, the arc-shaped elastic sheet 621 is used to provide elastic support to the resisting column 61, the rotation axis of the cylindrical cam 622 is perpendicular to the axis of the arc-shaped elastic sheet, and when the cylindrical cam 622 rotates, the degree of extrusion of the end of the arc-shaped elastic sheet 621 can be changed, so that the elastic force acting on the surface of the resisting column 61 changes. This changing elastic force can change the amount of elastic deformation of the resisting column 61 when it resists the inner wall of the positioning hole 41, so that the position between the probe card 4 and the positioning column 6 can be adjusted. Therefore, by adjusting the rotation amount of the cylindrical cam 622, the self-adapting adjustment distance when responding to different thermal deformations can be changed.

[0044] In some embodiments, the driving member 623 comprises a rotating rod 6231, a limiting disc 6232, a positioning pin 6233 and a compression spring 6234, the surface of the positioning column 6 is provided with a shaft hole 64, a plurality of positioning protrusions 65 are arranged on the circumferential surface of the shaft hole 64 near one end of the surface of the positioning column 6, a positioning groove 66 is formed between two adjacent positioning protrusions 65, the rotating rod 6231 is coaxially arranged in the shaft hole 64, the rotating rod 6231 is coaxially fixed with the limiting disc 6232 at one end near the surface of the positioning column 6, the surface of the limiting disc 6232 is protrusively provided with the positioning pin 6233, the limiting disc 6232 and the surface of the positioning column 6 are elastically connected through the compression spring 6234, the compression spring 6234 drives the limiting disc 6232 to abut against one side of the positioning protrusion 65 near the positioning column 6, the positioning pin 6233 is selectively clamped in one of the positioning grooves 66, and the compression spring 6234 can drive the positioning pin 6233 to be separated from the positioning groove 66, and the rotating rod 6231 can rotate relative to the shaft hole 64.

[0045] In the above embodiments, in order to realize the rotation driving of the cylindrical cam 622, the cooperation structure of the positioning pin 6233 and the positioning groove 66 is adopted to realize the angle locking of the limiting disc 6232, the limiting disc 6232 is compressed by the compression spring 6234, so that the limiting disc 6232 can maintain angle locking when it is not affected by other external forces, when adjustment is needed, the limiting disc 6232 is compressed to drive the compression spring 6234, so that the positioning pin 6233 is separated from the positioning groove 66, at this time, the limiting disc 6232 can be rotated to drive the cylindrical cam 622 to rotate, so as to realize the compression or release of the arc-shaped elastic piece 621, and to adjust the elastic force acting on the abutting column 61.

[0046] In some embodiments, the positioning column 6 is screw-connected and installed on the surface of the bearing platform 51.

[0047] In the above embodiments, the positioning column 6 adopts a modular structure, and the screw connection can realize installation, disassembly and replacement.

[0048] In some embodiments, the elastic washer 7 is further included, and the elastic washer 7 is clamped and arranged between the positioning column 6 and the bearing platform 51.

[0049] In the above embodiments, the elastic washer 7 can realize the compression of the positioning column 6, improve the installation stability, and allow the positioning column 6 to rotate around the axis, so as to adjust the direction of the abutting column 61, and through the adjustment of the direction of the abutting column 61, the thermal expansion size can be adapted and adjusted.

[0050] In some embodiments, the sealing ring 10 is further included, and the upper surface of the lower cover plate 2 is provided with an annular installation groove 22 along the opening of the test cavity 21, and the sealing ring 10 is embedded in the annular installation groove 22.

[0051] In the above embodiment, the sealing ring 10 is used to improve the sealing effect between the test cavity 21 and the PCB board.

[0052] In some embodiments, the bottom surface of the upper cover plate 1 is provided with a buffer cavity 11, and the surface of the PCB board 3 is provided with a vent hole, and the buffer cavity 11 is communicated with the test cavity 21 through the vent hole.

[0053] In the above embodiment, the buffer cavity 11 is used to balance the pressure of the upper and lower spaces of the PCB board, so as to avoid the deformation of the PCB board caused by the pressure difference.

[0054] In some embodiments, the diameter of the buffer cavity 11 is the same as that of the test cavity 21.

[0055] In the above embodiment, the buffer cavity 11 and the test cavity 21 with the same diameter can balance the stress on both sides of the PCB board.

[0056] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fixture for wafer burn-in testing, comprising: The utility model relates to a test device for probe card, which comprises an upper cover plate (1), a lower cover plate (2), a PCB board (3), a probe card (4) and a fixer (5), wherein the top of the lower cover plate (2) is provided with a test cavity (21), the PCB board (3) is fixedly arranged below the upper cover plate (1), the fixer (5) is used for fixing the probe card (4) below the PCB board (3), the PCB board (3) is arranged above the lower cover plate (2), and the fixer (5) and the probe card (4) are both located in the test cavity (21), characterized in that the utility model further comprises a positioning column (6), the fixer (5) is annular, the inner ring of the fixer (5) is radially protruded to form an annular bearing platform (51), a plurality of positioning columns are arranged on the surface of the bearing platform (51) in the circumferential direction, the edge of the probe card (4) is axially provided with a plurality of positioning holes (41), each positioning column (6) is correspondingly arranged with one positioning hole (41), the positioning column (6) is embedded in the positioning hole (41), the side surface of each positioning column (6) is elastically provided with a plurality of rebound force adjustable abutting columns (61) in the circumferential direction, the end of the abutting column (61) abuts against the inner surface of the positioning hole, the abutting column (61) can be elastically moved along the radial direction of the positioning column (6), the positioning column (6) further comprises a spring adjusting structure (62), the inner side of the positioning column (6) is provided with a plurality of accommodating cavities (63) in the circumferential direction, each accommodating cavity (63) is communicated with the side surface of the positioning column (6) through a limiting hole (631), each limiting hole (631) is embedded with an abutting column (61), the spring adjusting structure (62) is arranged in the accommodating cavity (63), the spring adjusting structure (62) elastically drives the abutting column (61) to reciprocate along its own axis and the spring force is adjustable, wherein the spring adjusting structure (62) comprises an arc spring (621), a cylindrical cam (622) and a driving member (623), the arc spring (621) is arranged in the accommodating cavity (63), and the convex surface of the arc spring (621) abuts against one end of the abutting column (61) close to the accommodating cavity (63), one end of the arc spring (621) along the circumferential direction abuts against the top of the accommodating cavity (63), and the other end abuts against the circumferential surface of the cylindrical cam (622), and the driving member (623) is used for driving the cylindrical cam (622) to rotate around the axis.

2. The clamp for wafer burn-in test of claim 1, wherein, The driving piece (623) comprises a rotating rod (6231), a limiting disc (6232), a positioning pin (6233) and a tightening spring (6234), the surface of the positioning column (6) is provided with a shaft hole (64), a plurality of positioning protrusions (65) are arranged on the surface of the positioning column (6) in the circumferential direction, the positioning grooves (66) are formed between the adjacent two positioning protrusions (65), the rotating rod (6231) is coaxially arranged in the shaft hole (64), the one end of the rotating rod (6231) close to the surface of the positioning column (6) is coaxially fixed with the limiting disc (6232), the surface of the limiting disc (6232) is protrusively provided with the positioning pin (6233), the limiting disc (6232) and the surface of the positioning column (6) are elastically connected through the tightening spring (6234), the tightening spring (6234) drives the limiting disc (6232) to abut against the one side of the positioning protrusion (65) close to the positioning column (6), the positioning pin (6233) is selectively clamped in one of the positioning grooves (66), the compressed tightening spring (6234) can drive the positioning pin (6233) to be separated from the positioning groove (66), and the rotating rod (6231) can rotate relative to the shaft hole (64).

3. The clamp for wafer burn-in test of claim 1, wherein, The positioning column (6) is screw-connected and installed on the surface of the bearing platform (51).

4. The clamp for wafer burn-in test of claim 3, wherein, The elastic washer (7) is clamped between the positioning column (6) and the bearing platform (51).

5. The clamp for wafer burn-in test of claim 1, wherein, The sealing ring (10) is embedded in the annular mounting groove (22).

6. The fixture for wafer burn-in testing of claim 1, wherein, The bottom surface of the upper cover plate (1) is provided with the buffer cavity (11), the surface of the PCB (3) is provided with the air hole, and the buffer cavity (11) is communicated with the test cavity (21) through the air hole.

7. The fixture for wafer burn-in testing of claim 6, wherein, The diameter of the buffer cavity (11) is the same as that of the test cavity (21).

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