Solder layer reciprocating bending and power cycle coupled stress testing device and testing method

Abstract

The invention discloses a solder layer reciprocating bending and power cycle coupled stress testing device and testing method, comprising a base, a clamping mechanism and a reciprocating bending mechanism, wherein a bracket and a slide groove are respectively provided on the base; the clamping mechanism is arranged on the slide groove and can slide on the slide groove, and is fixed by an L-shaped connecting frame arranged on the clamping mechanism so that the clamping mechanism does not slide, the bending reciprocating mechanism is fixed on the bracket, and a circuit board frame is fixed between the clamping mechanism and the reciprocating bending mechanism; a solder layer to be tested is pasted with a strain gauge and fixed on a circuit board after being sealed with epoxy resin, a circuit board chip on the solder layer is loaded with a micro PTC constant temperature heating sheet, the strain gauge is connected to a dynamic resistance strain gauge through a wire, the dynamic resistance strain gauge is connected to a computer, and the micro PTC constant temperature heating sheet is connected to a delay relay and a DC regulated power supply through a wire; the circuit board is driven to bend up and down by the reciprocating bending mechanism, so as to realize the solder layer reciprocating bending and power cycle coupled stress testing.

Description

Technical Field

[0001] The invention relates to the technical field of laboratory instruments and equipment, and in particular to a circuit board solder layer reciprocating bending and power cycle coupled stress testing device and testing method. Background Art

[0002] With the rapid development of science and technology, circuit boards have been widely used in various electronic products. In the actual use process, due to the complexity and diversity of the working environment, the circuit board will be subjected to certain mechanical loads, which will cause certain bending stress on the circuit board. In addition, during the use process, there are alternating cycles of power-on (on), operation, standby and power-off (off). Such a cycle process is a typical power cycle process. Therefore, the circuit board is still in a power cycle loading state in actual work. In such a power cycle process, the temperature of the device increases due to the power consumption of the circuit board, and thermal stress is generated due to the mismatch of the thermal expansion coefficients of various materials. The solder layer plays an important supporting and heat dissipation role in the circuit board. It is a key link in the packaging process and will directly affect the reliability of the entire electronic product. Therefore, it is necessary to study the coupling stress of the reciprocating bending of the solder layer and the simulated power cycle curve. However, how to measure accurately, we will find that there is still a lack of auxiliary devices required for this measurement operation. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a solder layer reciprocating bending and power cycle coupled stress testing device and testing method.

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

[0005] A solder layer reciprocating bending and power cycle coupled stress testing device comprises a base, a clamping mechanism and a reciprocating bending mechanism, wherein two ends of the upper surface of the base are respectively provided with a bracket and two symmetrical slide grooves; the clamping mechanism is arranged on the slide groove, the clamping mechanism can slide on the slide groove, slide to a specified position and be fixed by an L-shaped connecting frame arranged on the clamping mechanism so that the clamping mechanism does not slide, the bending reciprocating mechanism is fixed on the bracket, a circuit board is arranged between the clamping mechanism and the reciprocating bending mechanism, and two ends of the circuit board are clamped by the clamping mechanism and the reciprocating bending mechanism respectively; a strain gauge is pasted on the solder layer to be tested and is fixed on the circuit board after being sealed with epoxy resin, a micro PTC constant temperature heating sheet is loaded on the circuit board chip on the solder layer, the strain gauge is connected to a dynamic resistance strain gauge through a wire, the dynamic resistance strain gauge is connected to a computer, and the micro PTC constant temperature heating sheet is connected to a delay relay and a DC regulated power supply through a wire; the circuit board is driven to bend up and down by the reciprocating bending mechanism to realize the solder layer reciprocating bending and power cycle coupled stress testing.

[0006] The reciprocating bending mechanism comprises a support frame, a motor, a push-pull rod, a connecting piece, a rotating piece and a clamp; the support frame is an integrated right-angle support frame composed of two pieces A and B, the A piece of the support frame is fixed on the bracket, the motor is fixed on the bottom of one side of the B piece of the support frame, the output shaft of the motor passes through the B piece of the support frame and is connected to the rotating piece, the rotating piece is movably connected to one end of the connecting piece, the other end of the connecting piece is movably connected to the bottom end of the push-pull rod provided on the B piece of the support frame, the top end of the push-pull rod is fixedly connected to the clamp, the rotating piece is driven by the motor, the rotating piece drives the connecting piece, the connecting piece drives the push-pull rod and, so that the circuit board clamped on the clamp is bent up and down.

[0007] The motor is connected to a switching power supply and a speed regulator. The switching power supply controls the start and stop of the motor, and the speed regulator controls the rotation speed of the motor output shaft.

[0008] A testing method for a solder layer reciprocating bending and power cycle coupled stress testing device comprises the following steps:

[0009] 1) The circuit board is mounted between the clamping mechanism and the reciprocating bending mechanism, and both ends of the circuit board are clamped by the clamping mechanism and the reciprocating bending mechanism respectively;

[0010] 2) The solder layer to be tested is pasted with a strain gauge and sealed with epoxy resin and fixed on the circuit board. The circuit board chip on the solder layer is loaded with a micro PTC constant temperature heating piece. The strain gauge is connected to the dynamic resistance strain gauge through a wire. The dynamic resistance strain gauge is connected to the computer. The micro PTC constant temperature heating piece is connected to the delay relay and the DC regulated power supply through a wire.

[0011] 3) Turn on the switch power supply, and drive the circuit board to bend up and down through the reciprocating bending mechanism of the speed regulator. Turn on the DC regulated power supply to make the micro PTC constant temperature heating sheet heat up, and the solder layer of the circuit board generates thermal power. The corresponding voltage value is controlled by the DC regulated power supply and the delay relay to make the solder layer of the circuit board generate coupling stress of different sizes, thereby realizing the simulation of the power cycle curve;

[0012] 4) The coupling stress change data of the circuit board solder layer is transmitted to the dynamic resistance strain gauge and computer through the strain gauge for calculation and analysis, so as to realize the test of the reciprocating bending and power cycle coupling performance of the circuit board solder layer.

[0013] The present invention provides a solder layer reciprocating bending and power cycle coupled stress testing device and testing method. Compared with the prior art, the present invention has the following beneficial effects:

[0014] The circuit board is clamped by the clamping mechanism and the reciprocating bending mechanism, so that the circuit board is kept horizontal and does not creep. The circuit board is located between the clamping mechanism and the reciprocating bending mechanism and is fixed by bolts. The switch power supply is turned on, so that the reciprocating bending mechanism drives the circuit board to bend up and down, and the bending amplitude and speed of the circuit board are adjusted by the speed regulator. The DC regulated power supply is further turned on, and the micro PTC constant temperature heating sheet heats up to cause the circuit board solder layer to heat up, and the circuit board solder layer is controlled by the delay relay to perform thermal power circulation, and by adjusting the voltage value of the DC regulated power supply, the circuit board solder layer generates thermal power circulation of different amplitudes, and finally realizes the simulation of the thermal power circulation of the circuit board solder layer and the reciprocating bending coupling, so that the circuit board solder layer generates coupling stress of different magnitudes, and finally the coupling stress size change data of the circuit board reciprocating bending and power circulation is input into the dynamic resistance strain gauge and the computer through the circuit and serial port mode for calculation and analysis, so as to meet the experimental requirements. The device and method are simple, convenient and safe to operate during use, and can greatly improve the experimental efficiency and save more time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a solder layer reciprocating bending and power cycle coupled stress testing device of the present invention;

[0016] Figure 2 is a schematic diagram of the structure of the base;

[0017] Figure 3 Schematic diagram of the structure in which the strain gauge is pasted on the solder layer to be tested and then sealed with epoxy resin and fixed on the circuit board;

[0018] Figure 4 It is a structural schematic diagram of the back side of the reciprocating bending mechanism;

[0019] Figure 5 It is a structural schematic diagram of the front of the reciprocating bending machine;

[0020] Figure 6 is a structural schematic diagram of the clamping mechanism;

[0021] In the figure: 1. base 2. L-shaped connecting frame 3. DC regulated power supply 4. Delay relay 5. Clamping mechanism 6. Circuit board 7. Computer 8. Dynamic resistance strain gauge 9. Reciprocating bending mechanism 10. Speed ​​regulator 11. Switching power supply 12. Bolt 1-1. Slide 1-2. Bracket 6-1. Solder layer 6-2. Circuit board chip 6-3. Micro PTC constant temperature heating piece 6-4. Strain gauge 6-5. Epoxy resin 9-1. Motor 9-2. Support frame A piece 9-3. Support frame B piece 9-4. Rotating part 9-5. Connecting part 9-6. Push-pull rod 9-7. Clamp. DETAILED DESCRIPTION

[0022] The content of the present invention is further described below in conjunction with the drawings and embodiments, but the present invention is not limited thereto.

[0023] Example:

[0024] like Figure 1 , Figure 2 As shown, a solder layer reciprocating bending and power cycle coupled stress testing device comprises a base 1, a clamping mechanism 5 and a reciprocating bending mechanism 9, wherein two ends of the upper surface of the base 1 are respectively provided with a bracket 1-2 and two symmetrical slide grooves 1-1; the clamping mechanism 5 is arranged on the slide groove 1-1, and the clamping mechanism 5 can slide on the slide groove 1-1, slide to a specified position and be fixed by an L-shaped connecting frame 2 arranged on the clamping mechanism 5 so that the clamping mechanism 5 does not slide, the bending reciprocating mechanism 9 is fixed on the bracket 1-2, a circuit board 6 is arranged between the clamping mechanism 5 and the reciprocating bending mechanism 9, and the two ends of the circuit board 6 are respectively clamped by the clamping mechanism 5 and the reciprocating bending mechanism 9 through bolts; as shown Figure 3 As shown, the solder layer 6-1 to be tested is adhered with a strain gauge 6-4 and sealed with an epoxy resin 6-5 and then fixed on the circuit board 6. The circuit board chip 6-2 on the solder layer 6-1 is loaded with a micro PTC constant temperature heating sheet 6-3. The strain gauge 6-4 is connected to a dynamic resistance strain gauge 8 through a wire, and the dynamic resistance strain gauge 8 is connected to a computer 7. The micro PTC constant temperature heating sheet 6-3 is connected to a delay relay 4 and a DC regulated power supply 3 through a wire; the circuit board 6 is driven to bend up and down by a reciprocating bending mechanism 9, so as to realize the reciprocating bending of the solder layer 6-1 and the power cycle coupling stress test.

[0025] like Figure 4 , Figure 5 , Figure 6 As shown, the reciprocating bending mechanism 9 includes a support frame, a motor 9-1, a push-pull rod 9-6, a connecting member 9-5, a rotating member 9-4 and a clamp 9-7; the support frame is an integrated right-angle support frame composed of two pieces A and B, the A piece 9-2 of the support frame is fixed to the bracket 1-2 by bolts 12, the motor 9-1 is fixed to the bottom of one side of the B piece 9-3 of the support frame by bolts 12, and the output shaft of the motor 9-1 passes through the B piece 9-3 of the support frame and is connected to the rotating member 9-4 The rotating member 9-4 is movably connected to one end of the connecting member 9-5, and the other end of the connecting member 9-5 is movably connected to the bottom end of the push-pull rod 9-6 arranged on the support frame B plate 9-3. The top end of the push-pull rod 9-6 is fixedly connected to the clamp 9-7. The rotating member 9-4 is driven by the motor 9-1, the rotating member 9-4 drives the connecting member 9-5, and the connecting member 9-6 drives the push-pull rod 9-6, so that the circuit board 6 clamped in the clamp 9-7 and the clamping groove of the clamping mechanism 5 by the bolt 12 is bent up and down.

[0026] The motor is connected to a switching power supply 11 and a speed regulator 10. The switching power supply 11 controls the start and stop of the motor, and the speed regulator 10 controls the rotation speed of the motor output shaft.

[0027] A testing method for a solder layer reciprocating bending and power cycle coupled stress testing device comprises the following steps:

[0028] 1) The circuit board 6 is mounted between the clamping mechanism 5 and the reciprocating bending mechanism 9, and both ends of the circuit board 6 are clamped by the clamping mechanism 5 and the reciprocating bending mechanism 9 respectively;

[0029] 2) The solder layer 6-1 to be tested is pasted with a strain gauge 6-4 and sealed with epoxy resin 6-5 and then fixed on the circuit board 6. The circuit board chip 6-2 on the solder layer 6-1 is loaded with a micro PTC constant temperature heating sheet 6-3. The strain gauge 6-4 is connected to a dynamic resistance strain gauge 8 through a wire. The dynamic resistance strain gauge 8 is connected to a computer 7. The micro PTC constant temperature heating sheet 6-3 is connected to a delay relay 4 and a DC regulated power supply 3 through a wire.

[0030] 3) Turn on the switch power supply 11, and drive the circuit board 6 to bend up and down through the reciprocating bending mechanism 9 of the speed regulator 10, turn on the DC stabilized power supply 3, make the micro PTC constant temperature heating sheet 6-3 heat up, and the circuit board solder layer 6-1 generate thermal power, and control the corresponding voltage value through the DC stabilized power supply 3 and the delay relay 4, so that the circuit board solder layer 6-3 generates coupling stress of different sizes, thereby realizing the simulation of the power cycle curve;

[0031] 4) The coupling stress variation data of the circuit board solder layer 6-3 is transmitted to the dynamic resistance strain gauge 8 and the computer 7 through the strain gauge for calculation and analysis, so as to realize the test of the reciprocating bending and power cycle coupling performance of the circuit board solder layer.

Claims

1. A test method for a solder layer reciprocating bending and power cycle coupled stress test device, characterized in that: The test device comprises a base, a clamping mechanism and a reciprocating bending mechanism, and a bracket and two symmetrical slide grooves are respectively arranged at two ends of the upper surface of the base; the clamping mechanism is arranged on the slide groove, and the clamping mechanism can slide on the slide groove, and when it slides to a specified position, it is fixed by an L-shaped connecting frame arranged on the clamping mechanism so that the clamping mechanism does not slide, and the bending reciprocating mechanism is fixed on the bracket, and the circuit board is arranged between the clamping mechanism and the reciprocating bending mechanism, and the two ends of the circuit board are clamped by the clamping mechanism and the reciprocating bending mechanism respectively; the solder layer to be tested is pasted with a strain gauge and sealed with epoxy resin and then fixed on the circuit board, and the circuit board chip on the solder layer is loaded with a micro PTC constant temperature heating sheet, and the strain gauge is connected to a dynamic resistance strain gauge through a wire, and the dynamic resistance strain gauge is connected to a computer, and the micro PTC constant temperature heating sheet is connected to a delay relay and a DC regulated power supply through a wire; the circuit board is driven to bend up and down by the reciprocating bending mechanism to realize the reciprocating bending of the solder layer and the power cycle coupling stress test; The reciprocating bending mechanism comprises a support frame, a motor, a push-pull rod, a connecting piece, a rotating piece and a clamp; The support frame is an integrated right-angle support frame composed of two pieces A and B. The A piece of the support frame is fixed on the bracket, and the motor is fixed on the bottom of one side of the B piece of the support frame. The output shaft of the motor passes through the B piece of the support frame and is connected to the rotating member. The rotating member is movably connected to one end of the connecting member, and the other end of the connecting member is movably connected to the bottom end of the push-pull rod provided on the B piece of the support frame. The top end of the push-pull rod is fixedly connected to the clamp. The rotating member is driven by the motor, the rotating member drives the connecting member, and the connecting member drives the push-pull rod and, so that the circuit board clamped on the clamp is bent up and down; The testing method comprises the following steps: 1) The circuit board is mounted between the clamping mechanism and the reciprocating bending mechanism, and both ends of the circuit board are clamped by the clamping mechanism and the reciprocating bending mechanism respectively; 2) The solder layer to be tested is pasted with a strain gauge and sealed with epoxy resin and fixed on the circuit board. The circuit board chip on the solder layer is loaded with a micro PTC constant temperature heating piece. The strain gauge is connected to the dynamic resistance strain gauge through a wire, the dynamic resistance strain gauge is connected to the computer, and the micro PTC constant temperature heating piece is connected to the delay relay and the DC regulated power supply through a wire; 3) Turn on the switch power supply, and drive the circuit board to bend up and down through the reciprocating bending mechanism of the speed regulator. Turn on the DC regulated power supply to make the micro PTC constant temperature heating sheet heat up, and the solder layer of the circuit board generates thermal power. The corresponding voltage value is controlled by the DC regulated power supply and the delay relay to make the solder layer of the circuit board generate coupling stress of different sizes, thereby realizing the simulation of the power cycle curve; 4) The coupling stress change data of the circuit board solder layer is transmitted to the dynamic resistance strain gauge and computer through the strain gauge for calculation and analysis, so as to realize the test of the reciprocating bending and power cycle coupling performance of the circuit board solder layer.

2. The test method of a solder layer reciprocating bending and power cycle coupled stress test device according to claim 1, characterized in that: The motor is connected to a switching power supply and a speed regulator. The switching power supply controls the start and stop of the motor, and the speed regulator controls the rotation speed of the motor output shaft.

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