Welding spot mechanical behavior research test device considering boundary condition influence

Abstract

The invention provides a welding spot mechanical behavior research test device considering boundary condition influence, and the device comprises a welding spot welding structure test piece which is used for simulating the installation boundary of a welding spot in electronic equipment; the mechanical load actuator is used for applying a mechanical load to the welding spot welding structure test piece; and the environment load test box is used for loading the welding spot welding structure test piece and providing a specific temperature and humidity environment for the welding spot welding structure test piece.

Description

Technical Field

[0001] This invention belongs to the field of electronic device solder joint mechanical performance testing technology, specifically relating to an experimental device for studying the mechanical behavior of solder joints considering the influence of boundary conditions. Background Technology

[0002] With the rapid development of electronic packaging technology, electronic devices are becoming increasingly integrated. Solder joints, as connection nodes between various electronic components, play a crucial role in structural connection and electrical signal energy transmission during use. The mechanical performance changes and reliability of solder joints during use directly affect the overall structural design, service life, and reliability assessment of electronic devices. In actual use, solder joints are subjected to complex environmental loads, including the combined effects of mechanical, climatic, and electrical loads. External structural vibrations and impacts, the thermal effects generated during current conduction, and the thermal stress arising from differences in thermal matching between the solder joint and its boundaries all contribute to the high susceptibility of solder joints to fatigue fracture, interface damage, and electromigration failure, becoming a bottleneck restricting the reliability of high-end electronic devices.

[0003] Current research on the mechanical behavior of solder joints in electronic devices is hampered by limitations in experimental setups. Most studies only allow for single-material level specimens under single-environment loads or stable composite environmental loads, lacking the capability to withstand long-term loading of specimens under time-varying composite environments. More critically, single-material level specimens cannot demonstrate the significant impact of boundary conditions on the mechanical behavior of solder joints under complex long-term environments, leading to discrepancies between experimentally obtained patterns and actual operating conditions, thus significantly reducing the direct reference value of the experimental results. In summary, existing experimental equipment and methods cannot accurately capture the long-term complex environmental loads and mechanical behavior patterns of solder joints under real-world installation conditions. Therefore, there is an urgent need to design an experimental setup that considers the influence of boundary conditions to study the mechanical behavior of solder joints in electronic devices under complex long-term environments. Summary of the Invention

[0004] The purpose of this invention is to overcome one of the problems existing in the prior art and provide a test device for studying the mechanical behavior of weld joints that considers the influence of boundary conditions. At the same time, it can simultaneously or sequentially apply multiple composite loads such as temperature, humidity, vibration, impact, and energization to the test piece, and acquire the mechanical performance parameters of the test piece in real time during the test process to analyze the change law of the mechanical behavior of the test piece.

[0005] This invention provides an experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions, comprising: Solder joint welding structure test piece, used to simulate the installation boundary of solder joints in electronic equipment; A mechanical load actuator is used to apply a mechanical load to the welded structural test piece at the weld point. An environmental load test chamber is used to house the welded structure test piece and provide a specific temperature and humidity environment for the welded structure test piece.

[0006] Furthermore, the weld joint welding structure test piece includes: The first substrate is used to simulate the connection surface of electronic components connected to solder joints; The second substrate is used to simulate the connection surface of electronic devices connected to solder joints; The solder joints are connected to the welding end faces of the first substrate and the second substrate respectively by welding.

[0007] Furthermore, the mechanical load actuator includes: A clamping head is used to clamp the first substrate and the second substrate; Force sensor, used to detect the mechanical load applied to the welded structure test piece of the weld point described above; The actuator is directly connected to the mechanical load loading device to transmit the mechanical load. The adapter plate has its two ends connected to the force sensor and the actuator, respectively, to adapt to force sensors and actuators of different specifications.

[0008] Furthermore, the environmental load test chamber is a box structure, with a through hole on the opposite end face, the actuating rod passing through the through hole, and the welded structure test piece placed inside the environmental load test chamber.

[0009] Furthermore, the environmental load test chamber has a door and a viewing window. The viewing window is used to observe the state of the welded structure test piece and to measure the mechanical behavior of the weld material under the composite environment using non-contact measuring equipment.

[0010] Furthermore, a flexible seal is installed at the through hole, and the flexible seal, through which the actuating rod passes, seals the internal environment of the environmental load test chamber.

[0011] Furthermore, the first and second bases are integrally plate-shaped structures.

[0012] Furthermore, electrical connection ports are provided on the surfaces of the first and second substrates for connecting to external circuits, and applying current loads to the weld joint welding structure test piece through closed circuits.

[0013] The beneficial effects of this invention are as follows: 1. The weld joint mechanical testing device considering the influence of boundary conditions provided by the present invention takes into account the influence of boundary conditions under the actual use environment of the weld joint material. The designed weld joint welding structure test piece can more realistically simulate the possible changes of the connection interface of the weld joint under the combined environmental effects of temperature, humidity, force load and electrical load in the actual use environment, and can more realistically reflect the mechanical behavior change law of the weld joint during long-term use.

[0014] 2. The weld joint mechanical testing device provided by the present invention adopts a general modular design, which can be compatible with load actuators and load sensors of different types and sizes, and can also be compatible with the testing of comprehensive environmental test pieces of various materials.

[0015] 3. The weld joint mechanical testing device provided by this invention can acquire the mechanical behavior parameters of the weld joint under comprehensive environmental conditions by monitoring the force load and displacement deformation during the test, and conduct research on the mechanical behavior of the weld joint. Directly conducting mechanical performance tests after the initial test can reveal the changes in the mechanical performance parameters of the weld joint after undergoing complex service, providing data support for subsequent environmental adaptability assessments of electronic equipment and reliability assessments of electronic equipment under comprehensive environmental conditions required for combat applications. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the composition of a weld joint mechanical testing device considering the influence of boundary conditions according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the weld joint welding structure test piece according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the mechanical load actuator according to an embodiment of the present invention; Figure 4 This is a structural schematic diagram of an environmental load test chamber according to an embodiment of the present invention. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] Example 1 This embodiment provides an experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions, the structure of which is as follows: Figure 1-4 As shown, it includes: Solder joint welding structure test piece 1 is used to simulate the installation boundary of solder joints in electronic devices; Mechanical load actuator 2 is used to apply a mechanical load to the weld joint welding structure test piece 1; The environmental load test chamber 3 is used to house the welded structure test piece 1 and provide a specific temperature and humidity environment for the welded structure test piece 1.

[0019] The weld joint welding structure test piece 1 includes: The first substrate 11 is used to simulate the connection surface of electronic components connected to solder joints; The second substrate 12 is used to simulate the connection surface of an electronic device connected to the solder joint; Solder point 13 is connected to the welding end face of the first substrate 11 and the second substrate 12 respectively by welding.

[0020] The mechanical load actuator 2 includes: The clamping head 21 is used to clamp the first base 11 and the second base 12; Force sensor 22 is used to detect the mechanical load applied to the welded structure test piece 1 of the weld point described above; The actuator 24 is directly connected to the mechanical load loading device to transmit the mechanical load; The adapter plate 23 is connected at both ends to the force sensor 22 and the actuator 24 respectively, and is used to adapt to force sensors 22 and actuators 24 of different specifications.

[0021] The environmental load test chamber 3 is a box structure with a through hole on the opposite end face. The actuating rod 24 passes through the through hole, and the welded joint welding structure test piece 1 is placed inside the environmental load test chamber.

[0022] The environmental load test chamber has a door 31 and a viewing window 32, which is used to observe the state of the welded structure test piece 1.

[0023] A flexible sealing slit 33 is installed at the through hole, and the flexible actuating rod 24 passes through it to seal the internal environment of the environmental load test chamber.

[0024] The first base 11 and the second base 12 are plate-shaped structures as a whole.

[0025] The first substrate 11 and the second substrate 12 are provided with power connection ports 14 for connecting to external circuits and applying current load to the weld joint welding structure test piece through closed circuits.

[0026] Example 2 This embodiment provides an experimental device for studying the mechanical behavior of weld joints considering the influence of boundary conditions. The device first simulates the welding and installation process and boundary conditions of weld joints in electronic devices, designing a weld joint welding structure test piece 1 to simulate the actual boundary conditions of weld joints during use in electronic devices. Additionally, using commonly used displacement actuators as actuating components, a mechanical load actuator 2 compatible with different displacement actuators and test pieces is designed. Finally, to meet the observation and measurement needs during the experiment, an environmental load test chamber capable of real-time observation of the experimental state is designed. This experimental device is compatible with the testing and research needs of displacement actuators of various models and sizes, as well as test pieces of different materials and sizes.

[0027] The mechanical testing apparatus for weld joints considering the influence of boundary conditions includes a weld joint welded structure test piece 1, a mechanical load actuator 2, and an environmental load test chamber 3. The overall structure is shown in [reference needed]. Figure 1 .

[0028] Solder Joint Welding Structure Test Specimen 1: To simulate the actual installation boundary of solder joints in electronic devices, a solder joint welding structure test was designed. Solder Joint Welding Structure Test Specimen 1 includes a first substrate 11, a second substrate 12, and a solder joint 13. The first substrate 11 is made of the same material as the soldering position of the electronic component at the location of solder joint 13, simulating the connection surface between solder joint 13 and the electronic component. The solder joint 13 is made of the material of the solder joint under study, and the solder joint size and welding process are determined by comprehensively considering the solder joint size and welding process to be studied. The second substrate 12 is the substrate material of the electronic device where solder joint 13 is located. Considering the common materials used for solder joints in common BGA packages, in this embodiment, the first substrate 11 is made of commonly used copper, the solder joint 13 is made of common tin-lead solder PB63ZN37, and the second substrate 12 is also made of copper. The thickness of the solder joint 13 is 0.5mm, referencing the actual size of the solder joint. The soldering process is reflow soldering for BGA packages. After soldering, the test pieces are subjected to process X-ray inspection to check for solder voids, cracks, porosity, and other soldering quality indicators at the solder interface. Simultaneously, random checks are conducted on test pieces from the same batch to perform IMC layer inspection, controlling the IMC layer thickness to be no more than 0.1mm. Additionally, an M5 threaded hole is provided on both the first substrate 11 and the second substrate 12. During the experiment, an M5 connecting bolt can be used to connect the current-carrying wire to the substrate, forming a closed-loop power circuit to achieve stable current loading under comprehensive environmental conditions. A schematic diagram of the solder joint welding structure is shown below. Figure 2 .

[0029] Mechanical load actuator 2: The mechanical load actuator 2 adopts a universal modular structure design, mainly including an adjustable clamping head, a force sensor 22, an adapter plate 23, and an actuating rod 24. The clamping head 21 is an adjustable clamping structure, which can clamp the test specimen through adjustable jaws, providing both clamping and support at the test specimen's boundary while transmitting the mechanical load environment. The force sensor 22 can be converted for different test scales, replacing it with a mechanical sensor of appropriate range and sensitivity to monitor or control the mechanical load on the test specimen during the test. The adapter plate 23 is a universal-sized adapter plate, compatible with force sensors 22 and actuating rods 24 of different specifications. The actuating rod 24 is directly connected to the mechanical load loading device, such as a vibration table or hydraulic actuator, to transmit the load applied by the force load loading device to the test specimen. See Mechanical Load Actuator for details. Figure 3 .

[0030] Environmental Load Test Chamber 3: Used to provide environmental load conditions such as temperature and humidity for the test specimens. The environmental load test chamber has a box structure, including an environmental chamber door 31, a viewing window 32, and a flexible seal 33. The viewing window 32 is located at the environmental chamber door 31, allowing optical measuring instruments to measure and monitor the test specimens inside the chamber from outside, and observe the test status of the specimens. Through holes with universal adapter flanges are located at the center of the top and bottom surfaces of the test chamber. A pleated, sealed flexible seal 33 is installed at the through hole, allowing the displacement actuator to pass through the environmental chamber body to apply load to the test specimens. Simultaneously, the flexible seal prevents excessive hot gas flow at the actuator, ensuring stable temperature and humidity within the environmental chamber. The pleated design also allows measurement lines to pass through, achieving a combination of wired and wireless measurement. See Environmental Load Test Chamber for details. Figure 4 .

[0031] The mechanical testing device for weld joints can be used to complete experimental tests through the following steps: 1. Select a suitable force sensor 22 and actuator 24 according to the test load environment. Connect the clamping head 21 and the adapter plate 23 to the force sensor 22 by bolting them together with the corresponding bolts. Connect the actuator 24 and the adapter plate 23 by bolting. The actuator 24 passes through the flexible seal 33 of the environmental load test chamber and is connected and fixed to the force load loading device.

[0032] 2. Adjust the position of the force load agent, and use the clamping head to clamp the first base 11 and the second base 12 of the welded structure test piece 1 to maintain the stability of the system.

[0033] 3. Close the temperature chamber door 32 and conduct a comprehensive environmental test on the welded structure test piece 1 based on the service environment conditions. During the test, the temperature and displacement of the welded structure are measured and monitored through the visual observation window 32 and wired sensors. At the same time, the load is measured and controlled using the force sensor 22.

[0034] 4. Real-time monitoring and analysis of the deformation and force of the welded structure during the experiment to obtain the changing law of the mechanical behavior of the welded structure.

[0035] 5. For welded structures that have completed the comprehensive environmental test, mechanical tensile property tests are carried out directly after the test using the test system to obtain the mechanical property parameters of the weld after the comprehensive environmental action, and to study the change law of the mechanical properties of the weld under the combined environmental action.

[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. This invention provides an experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions, comprising: Solder joint welding structure test piece, used to simulate the actual installation state of solder joints in electronic devices; A mechanical load actuator is used to apply a mechanical load to the welded structural test piece at the weld point. An environmental load test chamber is used to house the welded structure test piece and provide a specific temperature and humidity environment for the welded structure test piece.

2. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 1, characterized in that, The weld joint welding structure test piece includes: The first substrate is used to simulate the connection surface of electronic components connected to solder joints and the interface for applying electrical loads. The second substrate is used to simulate the electronic device connection surface and electrical load loading interface connected to the solder joint; The solder joints are connected to the welding end faces of the first substrate and the second substrate respectively by welding.

3. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 2, characterized in that, The mechanical load actuator includes: A clamping head is used to clamp the first substrate and the second substrate; Force sensor, used to detect the mechanical load applied to the welded structure test piece of the weld point described above; The actuator is directly connected to the mechanical load loading device to transmit the mechanical load. The adapter plate has its two ends connected to the force sensor and the actuator, respectively, to adapt to force sensors and actuators of different specifications.

4. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 3, characterized in that, The environmental load test chamber is a box structure with a through hole on the opposite end face. The actuating rod passes through the through hole, and the welded structure test piece is placed inside the environmental load test chamber.

5. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 1 or 4, characterized in that, The environmental load test chamber has a door and a viewing window. The viewing window is used to observe the state of the welded structure test piece and can monitor and measure the mechanical behavior of the test piece through non-contact measurement methods.

6. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 4, characterized in that, A flexible seal is installed at the through hole, and the flexible seal seals the internal environment of the environmental load test chamber after the actuating rod passes through it.

7. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 2, characterized in that, The first and second bases are plate-shaped structures as a whole.

8. The experimental apparatus for studying the mechanical behavior of weld joints considering the influence of boundary conditions according to claim 7, characterized in that, The first and second substrates are provided with power connection ports on their surfaces for connecting to external circuits, and applying current loads to the weld joint welding structure test piece through closed circuits.

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