Device and method for measuring repeated bending and vibration coupling stress of solder joints of circuit board

Abstract

The invention discloses a circuit board solder joint repeated bending and vibration coupling stress testing device and method. The device comprises a vibration platform, a coupling stress testing mechanism, a dynamic strain gauge and a computer. The circuit board to be tested is arranged on the coupling stress testing mechanism, the coupling stress testing mechanism is horizontally fixed on the vibration platform, the vibration platform is connected with a vibration control system, a small signal of the vibration control system is amplified by a power amplifier, and a large signal of a certain voltage and current is output for use by the vibration platform. The circuit board to be tested is fixed on the coupling stress testing mechanism, a strain gauge is pasted on the solder joint of the circuit board to be tested, the strain gauge is connected with the dynamic strain gauge through a circuit, the dynamic strain gauge is connected with the computer, and repeated bending and vibration are applied to the circuit board to be tested through the repeated bending mechanism on the coupling stress testing mechanism and the vibration platform, so as to realize the measurement of repeated bending and vibration coupling stress.

Description

Technical Field

[0001] The invention relates to the technical field of laboratory instruments and equipment, and in particular to a device and method for measuring repeated bending and vibration coupling stress of a solder joint of a circuit board. Background Art

[0002] With the continuous development of science and technology, electronic products have begun to develop in the direction of low cost, low power, small size and multifunctionality, and the demand for electronic products is also increasing. In actual use, due to the complexity and diversity of the environment, electronic products will be affected by various mechanical loads, such as repeated bending, torsional deformation, random vibration, impact, etc. As a result, the solder joints on the circuit board in the electronic product will deform and fail, causing the entire electronic product to fail. In daily use, electronic products are usually subjected to continuous and uninterrupted loads. At present, there are many research projects in the engineering field involving the measurement of solder joint bending stress and vibration stress, but when conducting related scientific research, there is a lack of auxiliary devices specifically used for repeated bending and vibration stress research and measurement of solder joints, which leads to unsuccessful progress of the research project. Therefore, it is necessary to conduct reliability research on the circuit board solder joints under the dynamic coupling of repeated bending and vibration. How to measure accurately, we found that there is still a lack of auxiliary devices required for such measurement operations. Summary of the invention

[0003] The purpose of the present invention is to overcome the problems raised in the background technology and provide a device and method for measuring repeated bending and vibration coupling stress of a solder joint of a circuit board.

[0004] The technical solution for achieving the purpose of the present invention is:

[0005] A device for measuring the repeated bending and vibration coupling stress of a solder joint of a circuit board comprises a vibration platform, a coupling stress testing mechanism, a dynamic strain gauge and a computer; the circuit board to be tested is arranged on the coupling stress testing mechanism, the coupling stress testing mechanism is horizontally fixed on the vibration platform, the vibration platform is connected to a vibration control system, a small signal of the vibration control system is amplified by a power amplifier, and a large signal of a certain voltage and current is output for use by the vibration platform;

[0006] The coupling stress testing mechanism comprises a base, which is fixed on a vibration platform, and two symmetrical sliders are arranged on the upper surface of the base, and two symmetrical L-shaped connecting frames are arranged on the sliders, and a slide groove matching the slider is arranged at the bottom of the L-shaped connecting frame, and the L-shaped connecting frame can move on the slider through the slide groove, and a clamp is arranged in the middle of the L-shaped connecting frame, and a repeated bending mechanism is arranged on the slider between the two L-shaped connecting frames and can move on the slider, and the two ends of the circuit board to be tested are arranged between the two L-shaped connecting frames and clamped by the clamp, and the repeated bending mechanism clamps the two sides of the middle of the circuit board to be tested; strain gauges are pasted on the solder joints on the circuit board to be tested, and the strain gauges are connected to the dynamic strain gauges through circuits, and the dynamic strain gauges are connected to the computer, and repeated bending and vibration are applied to the circuit board to be tested through the repeated bending mechanism and the vibration platform to achieve the measurement of repeated bending and vibration coupling stress.

[0007] The repeated bending mechanism comprises a frame-type support frame, a slide groove matching the slider is provided at the bottom of the frame-type support frame, the frame-type support frame is arranged on the slider through the slide groove, two supports are fixedly provided on the two side plates in the frame-type support frame respectively, the two supports are connected by two guide columns, the two guide columns are provided with a circuit board fixture for clamping the circuit board to be tested, a first screw rod is provided on the circuit board fixture, the upper end of the first screw rod passes through the top support and is connected to the first bevel gear, the first bevel gear is meshed with the second bevel gear, the two second bevel gears are connected by a connecting rod, the connecting rod is fixed to the lower surface of the top of the frame-type support frame through a bearing support, the first screw rod, one of the screw rods has a lower end passing through the bottom support and meshing with the gear, and the gear is connected to the output shaft of the stepper motor.

[0008] The L-shaped connecting frame has two second screw rods between the two L-shaped connecting frames, one of which passes through the bearing seat on the frame-type support frame, one end of the two second screw rods passes through an L-shaped connecting frame and is fixed on the base through the bearing seat, and the other end passes through another L-shaped connecting frame and is connected to the third bevel gear on the rocker mechanism.

[0009] The slider is a trapezoidal slider.

[0010] A testing method for a circuit board solder joint repeated bending and vibration coupling stress measuring device comprises the following steps:

[0011] 1) First, place the coupling stress test mechanism on the vibration platform and fix it with bolts. Connect the vibration platform to the vibration control system and set the parameters.

[0012] 2) By turning the rocker on the rocker mechanism, the two L-shaped connecting frames and the frame-shaped support frame are controlled to slide, and the position suitable for placing the circuit board is adjusted. The two ends and the middle sides of the circuit board are clamped by the clamp on the L-shaped connecting frame and the circuit board clamp of the repeated bending mechanism to keep it horizontal and prevent creeping;

[0013] 3) The strain gauge is pasted on the solder joints on the circuit board, the strain gauge is connected to the dynamic strain gauge through the circuit, and the dynamic strain gauge is connected to the computer;

[0014] 4) Turn on the power supply, so that the rotation of the stepper motor drives the two circuit board fixtures on the repeated bending mechanism to move up and down at the same time, and the circuit board is driven to bend up and down repeatedly through the circuit board fixture;

[0015] 5) At the same time, by adjusting the vibration control system vibration platform to generate vibration, the circuit board will vibrate on the basis of repeated bending, thereby completing the coupling experiment of repeated bending and vibration; the strain gauge and dynamic strain gauge transmit the data of the change of coupling stress size of repeated bending and vibration to the computer through the circuit and serial port for calculation and analysis, so as to realize the test of repeated bending and vibration coupling stress of circuit board solder joints.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The two L-shaped connecting frames and the frame-shaped connecting frame are controlled to slide by rotating the rocker to adjust the position suitable for placing the circuit board, and the self-locking mechanism of the worm gear on the rocker is used to fix it. The two ends of the circuit board to be tested are clamped by the clamping device to keep it horizontal and prevent creeping, and the middle end of the circuit board to be tested is clamped by another clamping device. By setting the speed of the stepper motor, the stepper motor rotates to drive the gear to rotate, and the gear drives the screw to rotate, further driving the fixture fixing plate to move upward, and the bevel gear drives another fixture fixing plate to move upward to achieve the upward bending of the circuit board. The upward bending deformation of the circuit board is further calculated by calculating the speed of the stepper motor. By setting the stepper motor to reverse, the circuit board is driven to bend downward, and the repeated bending of the circuit board is further achieved. The device for realizing repeated bending of the circuit board is placed on the vibration platform, and the vibration time, amplitude and other parameters of the vibration platform are set by the vibration control system, so that the circuit board generates random vibration based on the repeated bending dynamics, and then the coupling stress size change data is input into the computer through the circuit and serial port, and calculation and analysis are started to meet the requirements of experimental research. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a coupling stress testing device for repeated bending and vibration of a circuit board solder joint;

[0019] Figure 2 It is a structural schematic diagram of a coupling stress testing mechanism;

[0020] Figure 3 is a schematic diagram of the base;

[0021] Figure 4 is a schematic diagram of an L-shaped connecting frame;

[0022] Figure 5 It is a structural schematic diagram of the repeated bending mechanism;

[0023] Figure 6 It is a structural schematic diagram of the rocker mechanism;

[0024] In the figure: 1. coupling stress test mechanism 2. power amplifier 3. vibration platform 4. dynamic strain gauge 5. vibration control system 6. base 7. bearing seat 8. L-shaped connecting frame 9. fixture 10. repeated bending mechanism 11. rocker mechanism 12. circuit board to be tested 13. second screw rod 14. slider 15. slide groove 16. frame support frame 17. stepper motor 18. gear 19. support 20. circuit board fixture 21. guide column 22. first bevel gear 23. second bevel gear 24. connecting rod 25. first screw rod 26. third bevel gear. DETAILED DESCRIPTION

[0025] The content of the present invention will be further described below in conjunction with the drawings and embodiments, but the present invention is not limited thereto.

[0026] A circuit board solder joint repeated bending and vibration coupling stress measurement device, comprising a vibration platform 3, a coupling stress test mechanism 1, a dynamic strain gauge 4 and a computer; the circuit board to be tested is arranged on the coupling stress test mechanism 1, the coupling stress test mechanism 1 is horizontally fixed on the vibration platform 3, the vibration platform 3 is connected to the vibration control system 5, the small signal of the vibration control system 5 is amplified by the power amplifier 2, and a large signal of a certain voltage and current is output for use by the vibration platform 3;

[0027] like Figure 2 As shown, the coupling stress testing mechanism 1 includes a base 6, which is fixed to the vibration platform 3 by screws or bolts through threaded holes. Figure 3 As shown, two symmetrical sliders 14 are provided on the upper surface of the base 6, and two symmetrical L-shaped connecting frames 8 are provided on the sliders 14. Figure 4 As shown, a slide groove 15 matching with the slider 15 is provided at the bottom of the L-shaped connecting frame 8, and the L-shaped connecting frame 14 can move on the slider 14 through the slide groove 15. A clamp 9 is provided in the middle of the L-shaped connecting frame 8. A repeated bending mechanism 10 is provided on the slider 14 between the two L-shaped connecting frames 7 and can move on the slider 14. Both ends of the circuit board 12 to be tested are arranged between the two L-shaped connecting frames 8 and are clamped by the clamp 9 through bolts. The repeated bending mechanism 10 clamps both sides of the middle of the circuit board 12 to be tested; strain gauges are pasted on the solder joints on the circuit board 12 to be tested, and the strain gauges are connected to the dynamic strain gauge 4 through the circuit, and the dynamic strain gauge 4 is connected to the computer. The circuit board 12 to be tested is subjected to repeated bending and vibration through the repeated bending mechanism 10 and the vibration platform 3, so as to realize the measurement of repeated bending and vibration coupling stress.

[0028] like Figure 5 As shown, the repeated bending mechanism 10 includes a frame-type support frame 16, a slide groove 15 matching the slider 14 is provided at the bottom of the frame-type support frame 16, the frame-type support frame 16 is arranged on the slider 14 through the slide groove 15, two supports 19 are fixedly provided on the two side plates in the frame-type support frame 16, the two supports 19 are connected by two guide columns 21, and the two guide columns 21 are provided with a circuit board fixture 20 for clamping the circuit board 12 to be tested, and the circuit board fixture 20 is provided with a first screw rod 25, the upper end of the first screw rod 25 passes through the top support 19 and is connected to the first bevel gear 22, the first bevel gear 22 is meshed with the second bevel gear 23, and the two second bevel gears 23 are connected by a connecting rod 24, and the connecting rod 24 is fixed to the lower surface of the top of the frame-type support frame 16 through a bearing support, and the lower end of one of the first screw rods 25 passes through the bottom support 19 and meshes with the gear 18, and the gear 18 is connected to the output shaft of the stepping motor 17.

[0029] The L-shaped connecting frame 8 is provided with two second screw rods 13 between the two L-shaped connecting frames 8, one of which passes through the bearing seat on the frame support frame 16, one end of the two second screw rods 13 passes through an L-shaped connecting frame 8 and is fixed on the base 6 through the bearing seat 7, and the other end passes through the other L-shaped connecting frame 8 and is connected to the third bevel gear 26 on the rocker mechanism 11, as shown in FIG. Figure 6 shown.

[0030] The slide block 14 is a trapezoidal slide block.

[0031] A testing method for a circuit board solder joint repeated bending and vibration coupling stress measuring device comprises the following steps:

[0032] 1) First, place the coupling stress test mechanism on the vibration platform and fix it with bolts. Connect the vibration platform to the vibration control system and set the parameters.

[0033] 2) By turning the rocker on the rocker mechanism, the two L-shaped connecting frames and the frame-shaped support frame are controlled to slide, and the position suitable for placing the circuit board is adjusted. The two ends and the middle sides of the circuit board are clamped by the clamp on the L-shaped connecting frame and the circuit board clamp of the repeated bending mechanism to keep it horizontal and prevent creeping;

[0034] 3) The strain gauge is pasted on the solder joints on the circuit board, the strain gauge is connected to the dynamic strain gauge through the circuit, and the dynamic strain gauge is connected to the computer;

[0035] 4) Turn on the power supply, so that the rotation of the stepper motor drives the two circuit board fixtures on the repeated bending mechanism to move up and down at the same time, and the circuit board is driven to bend up and down repeatedly through the circuit board fixture;

[0036] 5) At the same time, by adjusting the vibration control system vibration platform to generate vibration, the circuit board will vibrate on the basis of repeated bending, thereby completing the coupling experiment of repeated bending and vibration; the strain gauge and dynamic strain gauge transmit the data of the change of coupling stress size of repeated bending and vibration to the computer through the circuit and serial port for calculation and analysis, so as to realize the test of repeated bending and vibration coupling stress of circuit board solder joints.

Claims

1. A device for measuring repeated bending and vibration coupling stress of a circuit board solder joint, characterized in that: It includes a vibration platform, a coupling stress test mechanism, a dynamic strain gauge and a computer; the circuit board to be tested is arranged on the coupling stress test mechanism, the coupling stress test mechanism is horizontally fixed on the vibration platform, the vibration platform is connected to the vibration control system, the small signal of the vibration control system is amplified by the power amplifier, and a large signal of a certain voltage and current is output for use by the vibration platform; The coupling stress testing mechanism includes a base, which is fixed on a vibration platform, and two symmetrical sliders are arranged on the upper surface of the base, and two symmetrical L-shaped connecting frames are arranged on the sliders, and a slide groove matching the slider is arranged at the bottom of the L-shaped connecting frame, and the L-shaped connecting frame can move on the slider through the slide groove, and a clamp is arranged in the middle of the L-shaped connecting frame, and a repeated bending mechanism is arranged on the slider between the two L-shaped connecting frames and can move on the slider, and the two ends of the circuit board to be tested are arranged between the two L-shaped connecting frames and clamped by the clamp, and the repeated bending mechanism clamps the two sides of the middle of the circuit board to be tested; strain gauges are pasted on the solder joints on the circuit board to be tested, and the strain gauges are connected to the dynamic strain gauges through the circuit, and the dynamic strain gauges are connected to the computer, and repeated bending and vibration are applied to the circuit board to be tested through the repeated bending mechanism and the vibration platform to achieve the measurement of repeated bending and vibration coupling stress; The repeated bending mechanism comprises a frame-type support frame, a slide groove matching the slider is provided at the bottom of the frame-type support frame, the frame-type support frame is arranged on the slider through the slide groove, two supports are fixedly provided on the two side plates in the frame-type support frame respectively, the two supports are connected by two guide columns, the two guide columns are provided with a circuit board fixture for clamping the circuit board to be tested, a first screw rod is provided on the circuit board fixture, the upper end of the first screw rod passes through the top support and is connected to the first bevel gear, the first bevel gear is meshed with the second bevel gear, the two second bevel gears are connected by a connecting rod, the connecting rod is fixed to the lower surface of the top of the frame-type support frame through a bearing support, the lower end of one of the first screw rods passes through the bottom support and meshes with the gear, and the gear is connected to the output shaft of the stepping motor; The L-shaped connecting frame has two second screw rods between the two L-shaped connecting frames, one of which passes through the bearing seat on the frame-type support frame, one end of the two second screw rods passes through an L-shaped connecting frame and is fixed on the base through the bearing seat, and the other end passes through another L-shaped connecting frame and is connected to the third bevel gear on the rocker mechanism.

2. A circuit board solder joint repeated bending and vibration coupling stress measurement device according to claim 1, characterized in that: The slider is a trapezoidal slider.

3. The testing method of a circuit board solder joint repeated bending and vibration coupling stress measuring device according to claim 1, characterized in that: The steps include: 1) First, place the coupling stress test mechanism on the vibration platform and fix it with bolts. Connect the vibration platform to the vibration control system and set the parameters. 2) By turning the rocker on the rocker mechanism, the two L-shaped connecting frames and the frame-shaped support frame are controlled to slide, and the position suitable for placing the circuit board is adjusted. The two ends and the middle sides of the circuit board are clamped by the clamp on the L-shaped connecting frame and the circuit board clamp of the repeated bending mechanism to keep it horizontal and prevent creeping; 3) The strain gauge is pasted on the solder joints on the circuit board, the strain gauge is connected to the dynamic strain gauge through the circuit, and the dynamic strain gauge is connected to the computer; 4) Turn on the power supply, so that the rotation of the stepper motor drives the two circuit board fixtures on the repeated bending mechanism to move up and down at the same time, and the circuit board is driven to bend up and down repeatedly through the circuit board fixture; 5) At the same time, by adjusting the vibration control system vibration platform to generate vibration, the circuit board will vibrate on the basis of repeated bending, thereby completing the coupling experiment of repeated bending and vibration; the strain gauge and dynamic strain gauge transmit the data of the change of coupling stress size of repeated bending and vibration to the computer through the circuit and serial port for calculation and analysis, so as to realize the test of repeated bending and vibration coupling stress of circuit board solder joints.

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