A single board stress test fixture

Abstract

A single board stress test fixture, its characterized in that, including: base plate, including fixed position;At least 3 screw columns, one end is fixed on the fixed position, the other end is connected with test board;The height of the screw column is adjustable.The utility model discloses the influence of simulation stress to test board, whether the layout of test board screw hole is reasonable is tested, and whether the strength of test board is enough is tested.

Description

Technical Field

[0001] This utility model relates to the field of applied testing technology, specifically to a single-plate stress testing fixture. Background Technology

[0002] In modern electronics manufacturing and precision instrument production, stress testing of circuit boards is a crucial step in ensuring product quality and reliability. During actual use, circuit boards are subjected to stresses from various factors such as mechanical vibration, temperature changes, and assembly processes. If these stresses exceed the material's tolerance, they can lead to deformation, cracking, or even functional failure, severely impacting product lifespan and performance stability. Therefore, precise stress testing allows for the early detection of potential quality issues, enabling optimization of product design and manufacturing processes, thereby enhancing the overall competitiveness of the product.

[0003] Traditional single-board stress testing fixtures typically employ a fixed structure design with a fixed screw post height, making them suitable only for test boards of specific sizes and thicknesses. In actual production, due to variations in size, thickness, and mounting hole layout among different models and batches of single boards, fixed-structure fixtures cannot flexibly adapt when stress testing is required on boards of different specifications. This often necessitates frequent fixture replacements or customization, increasing production and time costs while reducing testing efficiency. Furthermore, fixed-height screw posts make it difficult to precisely control the stress loading method and magnitude on the test board, leading to significant errors in test results. These results fail to accurately reflect the stress state of the single board in actual use environments, thus affecting the accuracy and reliability of product quality assessment.

[0004] To address the problems of poor adaptability and inaccurate test results in existing single-plate stress testing fixtures, there is an urgent need to develop a new type of fixture that can flexibly adjust the height of the screw posts to adapt to single plates of different specifications and achieve accurate stress testing.

[0005] The above background information is provided only to aid in understanding the inventive concept and technical solution of this utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0006] Therefore, this utility model connects the base plate and the test plate by setting adjustable screw posts. By using the height difference of different screw posts, the stress caused to the test plate during the actual assembly process is generated, thereby simulating the effect of stress on the test plate. This allows for testing whether the layout of the screw holes on the test plate is reasonable and whether the strength of the test plate is sufficient. It can effectively overcome the shortcomings of the prior art, meet diverse testing needs, improve testing efficiency and accuracy, and is of great significance for ensuring product quality.

[0007] This utility model provides a single-plate stress testing fixture, characterized in that it includes: Substrate, including fixing position; At least three screw posts, one end of which is fixed to the fixing position, and the other end is connected to the test board; The height of the screw post is adjustable.

[0008] Optionally, the single-plate stress testing fixture is characterized in that the base plate includes a plurality of fixing positions so that the screw posts can be selectively fixed, thereby adjusting the relative positions of the screw posts.

[0009] Optionally, the single-plate stress testing fixture is characterized in that the fixing position is a threaded hole opened on the substrate, one end of the screw post is provided with an external thread adapted to the threaded hole, the screw post is fixed to the fixing position by the cooperation of the external thread and the threaded hole, and the connection height between the screw post and the test plate can be adjusted by rotating the screw post.

[0010] Optionally, the single-plate stress testing fixture is characterized in that the screw post includes a column body and an adjusting nut, one end of the column body is fixed to the fixed position, and the other end passes through a through hole on the test plate, the adjusting nut is disposed on the column body and located on the side of the test plate away from the substrate, and the connection height between the screw post and the test plate is adjusted by rotating the adjusting nut.

[0011] Optionally, the single-plate stress testing fixture is characterized in that the screw post includes a screw rod and a screw sleeve, the screw rod is fixedly connected to the fixed position, the screw sleeve is sleeved on the screw rod and threadedly connected to the screw rod, the end of the screw sleeve away from the substrate is connected to the test plate, and the height of the screw post is adjusted by rotating the screw sleeve.

[0012] Optionally, the single-plate stress testing fixture is characterized in that the substrate is made of aluminum alloy material.

[0013] Optionally, the single-plate stress testing fixture further includes a shim disposed between the screw post and the test plate.

[0014] Optionally, the single-plate stress testing fixture is characterized in that it further includes a scale mark, which is disposed on the screw post for visually displaying the height adjustment amount of the screw post.

[0015] Optionally, the single-plate stress testing fixture is characterized in that a sensor interface is further provided on the fixing position of the substrate for connecting a stress sensor to monitor the stress of the test plate in real time.

[0016] Optionally, the single-plate stress testing fixture is characterized in that the screw post is made of stainless steel to improve its strength and corrosion resistance.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In terms of adaptability, the adjustable height of the screw posts in this solution breaks through the limitations of traditional fixed structure fixtures. Different models and batches of single boards vary significantly in size, thickness, and mounting hole layout. The adjustable height of the screw posts allows for flexible adjustment of the connection with the test board. Whether it is a thin or thick single board, a stable connection can be achieved by adjusting the height of the screw posts, thus adapting to diverse testing needs and greatly expanding the application range of the fixture.

[0018] From the perspective of testing accuracy, the flexible adjustment of the screw post height allows for precise control over the stress loading method and magnitude applied to the test board. In actual stress testing, different usage scenarios and stress environments can be simulated by adjusting the screw post height according to the specific characteristics and testing requirements of the board. This allows the test board to be tested under conditions closer to actual use, effectively avoiding testing errors caused by improper stress loading. The test results accurately reflect the stress state of the board in the actual usage environment, providing a reliable basis for product quality assessment.

[0019] In terms of cost control and efficiency improvement, because this fixture can be adapted to various specifications of PCBs, companies no longer need to frequently change or re-customize fixtures for different specifications of PCBs, significantly reducing production and time costs. At the same time, the efficient and flexible adaptability reduces the time for fixture replacement and debugging, significantly improving the efficiency of stress testing, making the production testing process smoother, and further enhancing the company's competitive advantage in the market. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. Other features, objects, and advantages of this utility model will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of a single-plate stress testing fixture in an embodiment of this utility model; Figure 2 This is a top view of a single-plate stress testing fixture in an embodiment of this utility model; Figure 3 This is a test schematic diagram of an embodiment of the present utility model.

[0021] 1-Substrate; 2-Screw post; 3-Test board; Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0023] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the utility model described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] This utility model provides a single-plate stress testing fixture, which aims to solve the problems existing in the prior art.

[0025] The technical solutions of this utility model and this application solve the above-mentioned technical problems in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0026] like Figure 1 , Figure 2 and Figure 3 As shown, a single-plate stress testing fixture in this embodiment of the present invention includes: The substrate 1 includes a fixing position.

[0027] Specifically, the substrate is the fundamental load-bearing component of the entire single-plate stress testing fixture, acting as its "chassis" and providing a platform for the installation and fixation of other components. The fixing positions on the substrate are crucial areas for screw post installation. Through precise design and manufacturing, it is ensured that the screw posts can be securely installed in the fixing positions, forming a reliable connection between the screw posts and the substrate, thereby guaranteeing the overall stability of the fixture during testing. Furthermore, the substrate is typically made of high-strength, high-rigidity materials such as aluminum alloys and steel. These materials possess excellent mechanical properties, can withstand various stresses generated during testing, and are not easily deformed, providing a fundamental guarantee for testing accuracy. Simultaneously, the shape and size of the substrate can be customized according to actual application requirements to adapt to different testing environments and equipment layouts.

[0028] At least three screw posts 2, one end of which is fixed to the fixed position and the other end is connected to the test plate 3; the height of the screw posts is adjustable.

[0029] Specifically, the screw post, as a core component connecting the substrate and the test board, plays a crucial role in the fixture. One end is fixed to the mounting position on the substrate, ensuring a secure connection through threaded connections, welding, or other reliable fixing methods, guaranteeing that it will not loosen or fall off during testing. The other end of the screw post connects to the test board, used to fix and support the test board, placing it in the appropriate testing position.

[0030] The most prominent feature of the screw post is its height adjustability. This design is the key difference between this solution and traditional fixtures. Height adjustability can be achieved through various techniques. For example, a threaded adjustment structure can be incorporated into the screw post, allowing the extension length to be changed by rotating the screw post or its mating nut, thus adjusting its height. Alternatively, a nested structure can be used, where sleeves of different lengths are nested together and secured with a locking device to achieve height adjustment. By flexibly adjusting the screw post height, it is possible to precisely match test boards of different specifications. Whether it's a difference in test board thickness or a change in the height of the mounting holes, a tight and stable connection can be achieved by adjusting the screw post height, ensuring the test board remains stable during testing and avoiding testing errors caused by loose connections. Furthermore, the height-adjustable screw post can precisely control the stress loading method and magnitude on the test board according to different testing requirements. By simulating different usage scenarios and stress environments, the test results more realistically reflect the stress state of the board in actual use, improving the accuracy and reliability of the test.

[0031] The base plate and screw posts work together to form a complete single-plate stress testing fixture system. The base plate provides stable foundation support, while the screw posts connect to the test plate and allow for height adjustment based on the base plate. The arrangement of at least three screw posts forms a stable triangular or polygonal support structure, similar to a triangular truss in architecture. This effectively distributes the stress applied to the test plate during testing, preventing tilting or deformation due to uneven stress and ensuring the accuracy and consistency of the test. In actual testing, operators can first install and fix the screw posts to their fixed positions on the base plate according to the specific specifications of the test plate and the testing requirements. Then, by adjusting the height of the screw posts, the other end of the screw post is precisely aligned with the mounting holes on the test plate, completing the connection quickly and conveniently. This provides a reliable guarantee for efficient and accurate stress testing.

[0032] In some embodiments, the substrate includes multiple fixing positions to allow the screw posts to be selectively fixed, thereby adjusting the relative positions of the screw posts.

[0033] The inclusion of multiple fixing points on the substrate represents a significant upgrade in the flexibility and adaptability of the single-plate stress testing fixture. These multiple fixing points act as diverse "docking stations" for the screw posts, allowing them to be fixed at appropriate locations on the substrate according to testing requirements, thus enabling flexible adjustment of the relative positions of the screw posts.

[0034] From a design perspective, these fixing points are precisely laid out on the substrate, forming different point distributions. Their shape and size match the fixing ends of the screw posts, and common structural forms include threaded holes and positioning grooves. When stress testing is required on test boards of different specifications, the operator can select the corresponding fixing points on the substrate to install the screw posts based on the location of the test board's mounting holes, since the mounting hole layouts of different test boards vary. For example, for test boards with smaller mounting hole spacing, the screw posts can be fixed to the closer-spaced fixing points on the substrate; while for test boards with larger mounting hole spacing, the larger-spaced fixing points are selected for installation, ensuring that the screw posts can be precisely aligned with the mounting holes of the test board to achieve a stable connection.

[0035] The advantages of this design are significant. Firstly, it greatly enhances the fixture's adaptability to different test boards, overcoming the limitations of traditional fixtures with fixed screw post positions that can only accommodate test boards with specific mounting hole layouts. This allows for more diverse testing needs and reduces testing obstacles caused by fixture compatibility issues. Secondly, by flexibly adjusting the relative positions of the screw posts, the stress distribution on the test board can be altered, enabling the simulation of more complex stress loading methods that better reflect real-world usage scenarios. For example, when simulating eccentric stress on a single board, adjusting the screw post positions can create uneven stress on the test board, thus more realistically testing the board's performance under this stress state and further improving the accuracy and reliability of the test results.

[0036] In practical applications, the design of multiple fixing positions allows the fixture to easily handle stress testing of various models and batches of single boards in fields such as electronic product manufacturing and precision instrument production. Whether it is a circuit board for small consumer electronics products or a control board for large industrial equipment, the fixture and test board can be quickly adapted and installed by adjusting the mounting position of the screw posts on the substrate fixing position, which significantly improves testing efficiency and reduces the time and cost losses caused by frequent fixture changes or test equipment adjustments.

[0037] In some embodiments, the fixing position is a threaded hole formed on the substrate, and one end of the screw post is provided with an external thread that matches the threaded hole. The screw post is fixed to the fixing position by the cooperation of the external thread and the threaded hole, and its connection height with the test board can be adjusted by rotating the screw post.

[0038] In single-plate stress testing fixtures, the use of threaded holes for the fixing position and the design of an externally threaded screw post at one end is a crucial technical solution for achieving stable connection and flexible adjustment of the fixture. This design, through the precise fit of the threaded structure, securely mounts the screw post to the substrate while also providing height adjustment functionality, ensuring the accuracy and efficiency of stress testing.

[0039] From the perspective of the connection structure, the threaded holes on the substrate are machined with high precision. The pitch, thread angle, and other parameters of the internal threads strictly adhere to standard specifications to ensure tight engagement with the external threads of the screw post. The external threads at one end of the screw post are also finely manufactured with a high surface finish, and the thread accuracy perfectly matches the threaded holes on the substrate. During installation, the external threads of the screw post are screwed into the internal threads of the threaded holes on the substrate. As the rotation deepens, the friction between the two gradually increases, forming a reliable mechanical connection. This connection method can effectively resist external forces such as vibration and tension generated during testing, prevent the screw post from loosening, and ensure the stability of the fixture structure during testing.

[0040] In terms of height adjustment, the characteristics of the threaded connection are key to achieving changes in the height of the screw post. Due to the helix angle of the thread, when the operator rotates the screw post, it displaces along the axial direction of the threaded hole. Clockwise rotation causes the screw post to gradually screw into the threaded hole, decreasing the connection height with the test board; counterclockwise rotation causes the screw post to gradually screw out of the threaded hole, increasing the connection height. This method of height adjustment via rotation is simple to operate and offers controllable precision. Operators can quickly and accurately adjust the height of the screw post according to the actual specifications of the test board and testing requirements, ensuring precise alignment between the other end of the screw post and the test board, guaranteeing the test board is in the ideal testing position.

[0041] The design offers significant technical advantages. Firstly, the self-locking nature of the threaded connection ensures the screw post remains fixed after adjustment to the appropriate height, preventing height changes due to external forces during testing and thus ensuring the accuracy and consistency of test results. Secondly, compared to other connection methods, the threaded connection facilitates disassembly and reinstallation. When it's necessary to replace test plates of different specifications or maintain the fixture, operators can easily unscrew the screw post for quick replacement or repair, greatly improving the ease of use and maintenance efficiency of the fixture.

[0042] In practical applications, the threaded connection and height adjustment design allow the fixture to be widely adaptable to various single-board stress testing scenarios. Whether testing thin flexible circuit boards or performing stress testing on thick rigid circuit boards, the connection height can be flexibly adjusted by rotating the screw post, ensuring the test board is securely installed. Simultaneously, this precise height adjustment function can simulate various actual working conditions during testing, based on different stress loading requirements. This allows the test results to more realistically reflect the performance of the single board under complex usage environments, further enhancing the fixture's versatility and testing reliability, and providing strong support for the quality inspection of electronic products and precision instruments.

[0043] In some embodiments, the screw post includes a column and an adjusting nut. One end of the column is fixed to the fixed position, and the other end passes through a through hole on the test plate. The adjusting nut is disposed on the column and located on the side of the test plate away from the substrate. The connection height between the screw post and the test plate is adjusted by rotating the adjusting nut.

[0044] In this embodiment, the screw post adopts a structure combining a column and an adjusting nut. By adjusting the rotational displacement of the adjusting nut on the column, the connection height with the test plate can be precisely adjusted. This design breaks through the single adjustment mode of traditional threaded connections, significantly improving the ease of operation and testing accuracy of the fixture.

[0045] The screw post consists of two parts: a post body and an adjusting nut. The post body is typically a threaded rod made of a high-strength metal (such as stainless steel or aluminum alloy). One end of the post is tightly connected to the threaded hole in the substrate fixing position via external threads, ensuring stability during testing. The other end passes through a pre-drilled through-hole on the test plate. The diameter of this through-hole is slightly larger than the diameter of the post body to ensure that the post body can pass through smoothly without creating excessive gaps. The adjusting nut is a ring-shaped component with internal threads. Its thread specification is perfectly matched to the post body. It is screwed onto the post body and located on the side of the test plate away from the substrate. By rotating the adjusting nut, it can be moved axially along the post body.

[0046] When adjusting the connection height between the screw post and the test plate, the operator does not need to directly rotate the screw post; precise control can be achieved simply by turning the adjusting nut. The specific adjustment logic is as follows: 1. Height Reduction: Rotate the adjusting nut clockwise. The nut moves along the cylindrical thread towards the test plate, gradually pressing the test plate and reducing the distance between the test plate and the substrate, thereby reducing the connection height.

[0047] 2. Height Increase: Rotate the adjusting nut counterclockwise. The nut moves away from the test plate along the cylindrical thread, increasing the distance between the test plate and the base plate, thus increasing the connection height. This adjustment method utilizes the helical transmission principle of the threaded pair to convert rotational motion into linear motion. By controlling the number of rotations and angle of the adjusting nut, micron-level height adjustment accuracy can be achieved.

[0048] In practical stress testing scenarios, the design of the adjusting nut brings significant application advantages to the fixture: Flexible circuit board testing: For flexible circuit boards with large thickness variations, the deformation of the board can be compensated by fine-tuning the adjustment nut to ensure uniform stress distribution during the test.

[0049] Multi-batch product testing: When testing different batches and specifications of single boards, there is no need to change the screw posts. Simply adjust the nuts to quickly adapt them, greatly improving testing efficiency.

[0050] Precision stress loading: When simulating high-precision stress loading conditions, the adjusting nut can achieve a height adjustment accuracy of ±0.05mm, making the test results closer to the real use environment.

[0051] This embodiment achieves a perfect balance between connection stability and adjustment flexibility by separating the height adjustment function from the screw post body, providing an innovative solution for the intelligent and precise development of stress testing fixtures.

[0052] In some embodiments, the screw post includes a screw rod and a screw sleeve. The screw rod is fixedly connected to the fixing position, and the screw sleeve is sleeved on the screw rod and threadedly connected to the screw rod. The end of the screw sleeve away from the substrate is connected to the test plate, and the height of the screw post is adjusted by rotating the screw sleeve.

[0053] This embodiment employs a combination of a screw and a sleeve, utilizing the threaded transmission principle to achieve precise adjustment of the screw post height, providing a more flexible and reliable connection solution for single-plate stress testing. This design breaks through the traditional single adjustment mode of screw posts, significantly improving the adaptability of the fixture and the testing accuracy.

[0054] The screw post consists of two parts: a screw and a sleeve. The screw is typically made of high-strength alloy steel (such as 40Cr) or stainless steel. One end is machined with external threads that match the threaded hole in the substrate fixing position, achieving a rigid connection by screwing it into the substrate fixing position. The other end is a smooth rod structure with precision threads on its surface, serving as a guide for the movement of the sleeve. The sleeve is generally made of copper alloy (such as H62 brass) or aluminum alloy, with internal threads that match the screw threads. Externally, it is usually designed as a polygon (such as a hexagon) or has knurling for easy rotation using tools or manually. The end of the sleeve furthest from the substrate has a connecting structure (such as a positioning boss, mounting hole, etc.) for fixed connection with the test board.

[0055] The height adjustment of the screw-sleeve combination post is based on the helical transmission principle of the threaded pair. The screw is kept stationary through a threaded connection with the base plate, serving as the reference axis for height adjustment. The operator rotates the sleeve manually using a wrench; due to the threaded engagement between the sleeve and the screw, the sleeve moves linearly along the screw's axis. The direction of sleeve rotation determines the direction of height adjustment. Rotate the screw sleeve clockwise: The screw sleeve moves along the screw towards the base plate, and the overall height of the screw post decreases.

[0056] Rotate the screw sleeve counterclockwise: The screw sleeve moves away from the base plate along the screw rod, and the overall height of the screw post increases.

[0057] The accuracy of this adjustment method depends on the thread pitch. For example, with an M6×1.0 thread, the height can change by 1mm per revolution, and the adjustment accuracy can be achieved to ±0.02mm through fine-tuning.

[0058] The advantages of this embodiment include: 1. Improved adjustment efficiency: Compared with the traditional integral screw post, the screw sleeve structure can achieve height adjustment simply by rotating the sleeve, without the need to disassemble or reinstall the screw post, which greatly shortens the adjustment time.

[0059] 2. Enhanced load capacity: As the main load-bearing component, the screw can be made of high-strength materials and the thread parameters can be optimized (such as increasing the minor diameter of the thread), which significantly improves the axial load capacity of the screw stud, making it suitable for large-size or heavy-duty test plates.

[0060] 3. Optimized anti-loosening performance: The threaded pair between the sleeve and the screw has self-locking characteristics, which can effectively prevent height drift caused by vibration or stress changes during the test, ensuring the stability of the test data.

[0061] 4. Modular design: The screw and sleeve can be produced as independent components in a standardized manner, which facilitates mass production and maintenance replacement, and reduces production costs.

[0062] In some embodiments, the substrate is made of aluminum alloy. Using aluminum alloy as the substrate in a single-plate stress testing fixture is a preferred option after comprehensively considering material properties, processing technology, and practical application requirements. Aluminum alloy, with its unique physicochemical properties, provides strong support for the stability, reliability, and functionality of the fixture.

[0063] From a material properties perspective, aluminum alloys are a general term for aluminum-based alloys, typically with the addition of alloying elements such as copper, magnesium, and silicon, giving them excellent comprehensive properties. Firstly, aluminum alloys have a low density, approximately one-third that of steel. While ensuring the structural strength of the substrate, this effectively reduces the overall weight of the fixture, facilitating handling and installation by operators, making them particularly suitable for testing scenarios requiring frequent movement or repositioning. Secondly, aluminum alloys possess excellent corrosion resistance. A dense protective aluminum oxide film quickly forms on their surface in air, resisting corrosion from humid, acidic, and alkaline environments, extending the substrate's lifespan, reducing fixture damage and testing errors caused by material corrosion, and ensuring long-term stable operation.

[0064] In terms of mechanical properties, aluminum alloys, after appropriate heat treatment (such as solution treatment and aging treatment), can achieve high strength and hardness, enabling them to withstand various stresses applied to the substrate during testing, including the weight of the test board, the pressure transmitted by the screw posts, and the loads generated during stress testing. This ensures that the substrate is not easily deformed during use, maintains the precise positioning of the test board, and thus improves the accuracy and reliability of test results. Furthermore, aluminum alloys also possess good toughness, absorbing some energy when subjected to impact or vibration, preventing brittle fracture of the substrate and enhancing the impact resistance of the fixture.

[0065] From a processing perspective, aluminum alloys offer excellent machinability. Their good machinability allows for the easy fabrication of high-precision threaded holes on substrates through milling, drilling, and other machining processes, ensuring a tight and stable connection between the screw studs and the substrate. Furthermore, aluminum alloys are suitable for various forming processes, such as die casting and extrusion, allowing for the manufacture of substrates of different shapes and sizes to meet diverse application requirements. In addition, aluminum alloys offer a wide range of surface treatment options, including anodizing and electroplating, which can further enhance their appearance and protective properties. For example, anodizing creates a wear-resistant and aesthetically pleasing oxide film on the aluminum alloy surface, not only improving the substrate's wear resistance but also providing a decorative effect.

[0066] In practical applications, the use of aluminum alloy substrates significantly improves the overall performance of the fixture. In the production lines of electronics manufacturing companies, this fixture can be frequently used for stress testing of different types of single boards. The lightweight and corrosion-resistant properties of the aluminum alloy substrate enable it to adapt to high-intensity, high-humidity production environments; its excellent mechanical properties and processing precision ensure the stability of the fixture and the reliability of the test results during the testing process. This provides a strong guarantee for companies to improve production efficiency and reduce product defect rates, demonstrating good economic benefits and practical value.

[0067] In some embodiments, a gasket is also included, which is disposed between the screw post and the test plate.

[0068] In single-plate stress testing fixtures, the gasket, as a key component placed between the screw post and the test plate, significantly improves the connection stability, stress distribution uniformity, and testing accuracy of the fixture through optimization of material properties and structural design, and is an important link to ensure the reliability of test results.

[0069] The thickness of the shim needs to be determined based on the diameter of the screw post and the material of the test plate, generally 5% to 10% of the screw post diameter. A shim that is too thick will reduce connection rigidity, while one that is too thin will not effectively distribute stress. For example, an M6 screw post should be paired with a shim with a thickness of 0.3mm to 0.6mm. The inner diameter of the shim should be 0.5mm to 1mm larger than the screw post diameter to ensure that the screw post can pass through smoothly without jamming. For example, an M6 screw post should be paired with a shim with an inner diameter of Φ6.5mm. Metal shims can be galvanized or phosphated to improve corrosion resistance; non-metallic shims can have lubricants (such as silicone oil) added to reduce the coefficient of friction and facilitate installation and adjustment.

[0070] The selection of gasket materials requires comprehensive consideration of factors such as hardness, elastic modulus, corrosion resistance, and temperature stability. Commonly used materials include: 1. Metal gaskets: such as copper gaskets (H62 brass) and aluminum gaskets (6061 aluminum alloy), have high hardness and thermal conductivity, and are suitable for high-temperature environments or testing scenarios that require rapid heat dissipation.

[0071] 2. Non-metallic gaskets: such as polytetrafluoroethylene (PTFE) and silicone, have good flexibility and insulation, which can effectively avoid electrochemical corrosion caused by direct contact between the screw post and the test plate.

[0072] 3. Composite gaskets: such as metal-clad non-metal gaskets, which combine the strength of metals with the sealing performance of non-metals, and are suitable for complex testing environments with high pressure and high humidity.

[0073] The functions of gaskets include: 1. Stress Dispersion: By increasing the contact area between the screw post and the test plate, the shim transforms concentrated stress into uniformly distributed surface pressure. For example, when a preload of 10 N·m is applied to the screw post, the local pressure on the test plate without a shim can reach 20 MPa, while adding a 0.5 mm thick silicone shim can reduce the pressure to below 5 MPa, effectively preventing microcracks or deformation of the test plate caused by stress concentration.

[0074] 2. Buffering and Vibration Reduction: The elastic deformation characteristics of the gasket can absorb vibration energy during the test, reducing the relative displacement between the screw post and the test plate. In high-frequency vibration tests (such as 100Hz~500Hz), silicone gaskets can reduce the vibration transmission rate by 30%~50%, significantly improving the stability of test data.

[0075] 3. Insulation Protection: For test scenarios requiring electrical insulation (such as circuit board withstand voltage testing), the volume resistivity of PTFE gaskets can reach 10¹⁰. 6 Ω·cm can effectively isolate the current conduction between the screw post and the test board, avoiding the influence of electromagnetic interference on the test results.

[0076] 4. Surface Protection: The gaskets prevent the screw posts from scratching or indenting the test board surface during installation or adjustment. For example, the surface hardness of an aluminum alloy test board is approximately HB60, while the hardness of a copper gasket is HB40~50. The difference in material hardness protects the test board.

[0077] In some embodiments, a scale mark is also included, which is disposed on the screw post to visually display the height adjustment amount of the screw post.

[0078] The design of adding scale markings to the screw post in the single-plate stress testing fixture effectively solves the problem of lack of intuitive reference for height adjustment in traditional fixtures by making the height adjustment amount visible. This significantly improves the ease of operation and testing accuracy, and is an important optimization of the fixture's functionality and usability.

[0079] Scale markings are typically created on the surface of screw studs using processes such as laser engraving, etching, or printing. Laser engraving uses a high-energy laser beam to etch high-precision scale lines onto the screw stud surface, resulting in clear, wear-resistant, and fade-resistant lines. Etching utilizes chemical corrosion to create grooved scales on the screw stud surface, offering good wear resistance. Printing is relatively simple, using special inks to print the scale pattern onto the screw stud surface; it is low-cost but requires attention to ink adhesion and durability. The scale spacing is designed based on the screw stud's pitch and adjustment accuracy requirements. For example, for a screw stud with a 1mm pitch, to achieve an adjustment accuracy of 0.1mm, each thread turn can be divided into 10 graduations, each representing a 0.1mm height change, ensuring operators can precisely control the screw stud's height adjustment.

[0080] In the single-board stress testing stage of mass production of electronic products, single boards of the same model often need to undergo multiple repetitive tests. The presence of scale markings ensures that the height adjustment of the screw posts remains consistent each time, guaranteeing the stability of test conditions and the comparability of test results, providing a reliable guarantee for the consistent assessment of product quality. Furthermore, during the R&D phase, when conducting stress tests on single boards with different design schemes, R&D personnel can accurately record the height data for each adjustment based on the scale markings, analyze the stress response of the single board under different height settings, provide data support for optimizing product design, accelerate the product development process, and reduce R&D costs.

[0081] In some embodiments, a sensor interface is also provided on the fixing position of the substrate for connecting a stress sensor to monitor the stress of the test board in real time.

[0082] The sensor interface design enables the fixture to perform real-time stress monitoring, achieving an upgrade from manual adjustment to intelligent detection. In the single-plate stress testing fixture, the addition of a sensor interface at the substrate fixing position allows for real-time stress monitoring through integrated stress sensors. This transforms the traditional fixture from a simple physical support tool into an intelligent detection system with data acquisition and analysis capabilities, significantly improving the automation level and reliability of the testing process.

[0083] I. Interface Structure and Connection Method Sensor interfaces typically employ a standardized design and include the following key components: 1. Electrical connection module: It adopts a waterproof aviation plug (such as M12 interface) with 3-5 built-in contacts for power supply (+5V), ground (GND), signal transmission (Analog / Digital) and optional shielding layer connection, ensuring stable signal transmission in complex industrial environments.

[0084] 2. Mechanical fixing structure: The interface is designed with positioning pins and locking nuts, which can be precisely matched with the flange of the stress sensor to realize the quick installation and removal of the sensor. At the same time, it ensures that the force direction of the sensor coincides with the axis of the screw column, and the measurement error is controlled within ±0.5%.

[0085] 3. Protective design: The interface surface is covered with a silicone sealing ring, which can effectively prevent dust and liquid intrusion under the IP65 protection level, extending the service life of the interface.

[0086] II. Monitoring Principles and Signal Processing 1. Working principle of the sensor: The stress sensor is based on the principle of resistance strain gauge. When the test plate is deformed by force, the strain gauge attached to the elastic body of the sensor generates a change in resistance. The change in resistance is converted into a voltage signal (usually 0-10mV) through a Wheatstone bridge.

[0087] 2. Signal Conditioning: The interface has a built-in signal amplifier to amplify the weak sensor signal to a standard 0-5V voltage signal. At the same time, the integrated filter circuit suppresses 50Hz / 60Hz power frequency interference to ensure a signal-to-noise ratio >80dB.

[0088] 3. Data Acquisition and Transmission: After the signal is converted into a digital signal by the analog-to-digital converter (ADC), it is transmitted to the data acquisition system via RS485 bus or industrial Ethernet (such as Modbus / TCP protocol). The sampling frequency can reach up to 1kHz, which meets the requirements of dynamic stress testing.

[0089] III. Functional Advantages and Application Value 1. Real-time monitoring and feedback: The stress sensor connected through the sensor interface can acquire stress distribution data of the test board in real time during the loading process. Operators can intuitively observe the stress change curve through the supporting software interface. When the stress value exceeds the preset threshold, an alarm will be automatically triggered to avoid damage to the test board due to overload.

[0090] 2. Data Recording and Analysis: The system automatically records stress data for each test and supports the generation of analysis reports such as stress-time curves and stress distribution cloud maps, providing quantitative basis for R&D personnel to optimize product design. For example, by analyzing the differences in stress distribution under different height adjustments, the optimal screw stud height parameters can be determined.

[0091] 3. Process Automation and Standardization: The standardized design of the sensor interface facilitates integration into industrial automation systems. Combined with the stepper motor-driven screw height adjustment mechanism, it enables fully automated control of the testing process, ensuring consistency of test conditions for each test and improving the reliability and repeatability of test results.

[0092] 4. Fault diagnosis and predictive maintenance: By monitoring the trend of stress data changes over a long period of time, potential faults such as loose screws and aging sensors can be detected in advance, enabling predictive maintenance of equipment and reducing downtime and maintenance costs.

[0093] The sensor interface design transforms traditional fixtures from passive physical tools into active data acquisition terminals, enabling the digitization and intelligentization of the testing process through real-time stress monitoring, and providing electronic manufacturing companies with more efficient and accurate quality control methods.

[0094] In some embodiments, the screw post is made of stainless steel to improve its strength and corrosion resistance.

[0095] In the single-plate stress testing fixture, the screw posts are made of stainless steel, based on a thorough consideration of the fixture's requirements for high strength, high stability, and long service life. Stainless steel, with its excellent mechanical properties and corrosion resistance, provides a solid guarantee for the reliable operation of the screw posts in complex testing environments, significantly improving the overall performance of the fixture.

[0096] Stainless steel is an alloy steel formed by adding alloying elements such as chromium, nickel, and molybdenum to steel. Its core properties make it an ideal material for manufacturing screw studs. The chromium content is usually not less than 10.5%, which can quickly form a dense chromium-rich oxide film on the surface of the screw stud. This film, only a few nanometers thick, can effectively isolate oxygen, moisture, and corrosive media from contact with the metal substrate, giving the screw stud excellent corrosion resistance. Taking 304 stainless steel as an example, in a normal atmospheric environment, it can maintain a smooth surface for a long time and is not easy to rust; in a weakly acidic or alkaline environment, its corrosion rate is reduced by tens of times compared to ordinary steel, greatly extending the service life of the screw stud.

[0097] From a mechanical property perspective, stainless steel possesses high strength and hardness. Its strength can be further enhanced through cold working or heat treatment. For example, after cold drawing, 316L stainless steel can achieve a tensile strength exceeding 520 MPa and a yield strength exceeding 205 MPa. This allows it to withstand the significant pressure, tension, and alternating stress generated by vibration applied to the test plate during testing, ensuring that the screw studs are not prone to deformation or breakage during long-term use, maintaining the stability of the fixture structure, and thus guaranteeing the accuracy and reliability of test results. Simultaneously, stainless steel also possesses good toughness; even under significant external impact, it can absorb energy through moderate deformation, avoiding brittle fracture and reducing test interruptions and equipment failures caused by screw stud damage.

[0098] In the single-board stress testing stage of mass production of electronic products, the advantages of stainless steel studs are fully demonstrated. For example, in the stress testing of mobile phone test boards, a large number of test boards need to be tested every day. The studs frequently bear the weight and stress loading of the test boards, and the stainless steel studs can maintain stable support performance, ensuring the consistency and accuracy of the tests. In the testing of automotive electronic control units (ECUs), since the test environment may include factors such as high temperature and vibration, the high strength and good temperature resistance of stainless steel studs enable them to work reliably under complex working conditions, providing strong support for the quality inspection of ECUs and helping companies produce higher-quality electronic products.

[0099] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this utility model. Therefore, this utility model is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. A single-plate stress testing fixture, characterized in that, include: Substrate, including fixing position; At least three screw posts, one end of which is fixed to the fixing position, and the other end is connected to the test board; The height of the screw post is adjustable.

2. The single-plate stress testing fixture according to claim 1, characterized in that, The substrate includes multiple fixing positions to allow the screw posts to be selectively fixed, thereby adjusting the relative positions of the screw posts.

3. The single-plate stress testing fixture according to claim 1, characterized in that, The fixing position is a threaded hole opened on the substrate. One end of the screw post is provided with an external thread that matches the threaded hole. The screw post is fixed to the fixing position by the cooperation of the external thread and the threaded hole. The connection height between the screw post and the test board can be adjusted by rotating the screw post.

4. A single-plate stress testing fixture according to claim 1, characterized in that, The screw post includes a column body and an adjusting nut. One end of the column body is fixed to the fixed position, and the other end passes through a through hole on the test plate. The adjusting nut is disposed on the column body and located on the side of the test plate away from the substrate. The connection height between the screw post and the test plate is adjusted by rotating the adjusting nut.

5. A single-plate stress testing fixture according to claim 1, characterized in that, The screw post includes a screw rod and a screw sleeve. The screw rod is fixedly connected to the fixed position. The screw sleeve is sleeved on the screw rod and threadedly connected to the screw rod. The end of the screw sleeve away from the substrate is connected to the test plate. The height of the screw post can be adjusted by rotating the screw sleeve.

6. A single-plate stress testing fixture according to claim 1, characterized in that, The substrate is made of aluminum alloy.

7. A single-plate stress testing fixture according to claim 1, characterized in that, It also includes a gasket disposed between the screw post and the test plate.

8. A single-plate stress testing fixture according to claim 1, characterized in that, It also includes a scale marking, which is set on the screw post to visually display the height adjustment amount of the screw post.

9. A single-plate stress testing fixture according to claim 1, characterized in that, The substrate is also equipped with a sensor interface at its fixed position for connecting a stress sensor to monitor the stress of the test board in real time.

10. A single-plate stress testing fixture according to claim 1, characterized in that, The screw post is made of stainless steel to improve its strength and corrosion resistance.

Images