First piece test method and device for preventing solder pad from being damaged by tin lifting of smt tin paste plate in front of furnace

Abstract

The application discloses a first piece testing method and device for preventing solder pad damage of SMT tin paste plate by slightly lifting and avoiding tin. The method is to clamp and return the component under the same coordinate, which guarantees the position accuracy of the component return to the maximum extent and prevents the component from being damaged due to the testing process. The testing process is only slightly lifting, and the height is only 0.3-1.0 mm, which can effectively prevent the whole plate from being damaged due to the flying material. The component is completely separated from the tin paste during the testing process, and the testing precision is accurate and reliable. The probe clamping material width is elastically adjustable, the component is prevented from being clamped and damaged, and the method is safe and reliable. The lower needle Z-axis is elastically floated and prewarned, the component or the PCB is prevented from being damaged due to the misjudgment and overpressure, and the control is accurate.

Description

Technical Field

[0001] This invention relates to the field of PCB board testing technology, and in particular to a first article testing method and apparatus for micro-lifting of solder paste board before SMT reflow oven to avoid solder damage to solder pads. Background Technology

[0002] To ensure product quality and reduce material waste during SMT production, the first PCBA board produced for each work order requires component performance testing. This prevents production defects caused by defective components, incorrect component loading, component mixing, or incorrect placement procedures. This process is called first-article testing. Because first-article testing focuses on the parameters of components on the PCBA board, it's crucial to avoid interference from PCB traces, solder paste, and other components. This necessitates creating an insulated environment for the tested component, ensuring it only contacts the test probes. In SMT production, solder paste is first printed onto the PCB where components will be mounted. The components are then placed on the solder paste, which connects them to the PCB. After high-temperature reflow soldering, the connection is cured. Ideally, first-article testing should directly test the solder paste boards awaiting reflow curing on the SMT production line. The solder paste board structure is as follows... Figure 1 As shown.

[0003] Testing solder paste boards requires precise and complete separation of electronic components from the PCB board and the solder paste on the PCB. One existing method involves manually picking up the electronic components with tweezers, testing them, and then manually attaching them back to the PCB. This method is time-consuming and labor-intensive, and manual placement is prone to errors. Another method involves pre-applying double-sided adhesive tape to the surface of the PCB board, then using a pick-and-place machine to attach the components to the tape. The double-sided tape isolates the components from the PCB and secures them. This type of test sample is called an adhesive strip. However, after testing with adhesive strips, the entire PCBA board is often scrapped due to cleaning difficulties, resulting in material waste. Furthermore, the manufacturing process is time-consuming and labor-intensive, requiring specialized personnel, which increases the cost of first-article testing.

[0004] Another testing method is to perform blind testing, where the equipment directly identifies the electronic components and then uses clamping tools to test them. However, this method has very low accuracy. When clamping electronic components, the clamping device can easily cause solder scraping and damage to the pads, which can lead to product defects such as open solder joints and cold solder joints after passing through the SMT reflow oven.

[0005] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a first article testing method and device for micro-lifting of solder paste board to avoid solder damage to pads in SMT reflow oven, so as to solve the problems mentioned in the background art.

[0007] The technical solution of the present invention is as follows: A first-piece testing method for slightly lifting solder paste on an SMT reflow board to avoid solder damage to pads is provided, comprising the following steps: S1: Position and install the PCBA board to be tested onto the test fixture to achieve precise and secure fixation of the PCBA board; run the automatic testing equipment to test the PCBA board to be tested; the automatic testing equipment includes a test probe assembly for clamping components, the test probe assembly includes: a Z-axis lifting assembly, a rotating assembly, two probe bodies, two sets of probe drive assemblies, two Z-axis floating units, two X-axis floating units, and a ranging unit. The rotating assembly is mounted on the Z-axis lifting assembly and can achieve Z-axis movement under the drive of the Z-axis lifting assembly. Both probe drive assemblies are equipped with... The probe body is mounted on the rotating assembly and can rotate under its drive. The two probe bodies are respectively connected to the two corresponding probe driving assemblies. The two probe bodies can move closer or further apart under the drive of the two probe driving assemblies. Each probe body is connected to a Z-axis floating unit and an X-axis floating unit. The Z-axis floating unit and the X-axis floating unit are used to adjust the Z-axis floating amount and X-axis floating amount of the corresponding probe body, respectively. The ranging unit is connected to the Z-axis lifting assembly and is used to detect the distance to the component under test on the solder paste board below.

[0008] S2: Scan the height of each component under test on the PCBA board to obtain the height data of each component under test; and send the obtained height data of each component under test to the automatic testing equipment.

[0009] S3: The automatic testing equipment calculates the test clamping height of the corresponding component under test based on the pre-stored clamping depth parameters of components with different package sizes and the solder paste thickness parameters on the PCBA board surface.

[0010] S4: The automatic testing equipment controls the probe body to run to the calculated test clamp height position, and drives the probe to close to clamp and fix the test component according to the preset clamping force corresponding to the package size of different test components.

[0011] S5: The probe body is driven by the Z-axis lifting assembly to lift the clamped component under test by 0.3-1.0mm, so that the component under test is separated from the solder paste layer on the PCBA board, thus preventing poor electrical connection problems such as solder bridges and solder bridging between the component under test and the solder paste layer.

[0012] S6: The automatic test equipment starts the electrical test module to read the test values ​​of the component under test. After the test values ​​stabilize, the probe body is driven by the Z-axis lifting component to reset the component under test and place it in the original installation position on the PCBA board.

[0013] S7: Delay preset duration, wait for the test component to form a stable bond with the solder paste on the PCBA board, then control the probe body to open and lift to reset.

[0014] S8: Complete the testing of all components under test on the PCBA board in sequence.

[0015] The automatic testing equipment includes a height detection component that can detect the height value of each component under test on the solder paste board. In step S2, the height value of each component under test on the solder paste board is detected by the automatic testing equipment.

[0016] The ranging unit and the height detection component are either a dot matrix laser sensing device, a linear scanning laser sensing device, or a 3D camera device.

[0017] The automated testing equipment also includes a test follow-up camera assembly for capturing images of the clamping position of the probe body during testing.

[0018] This invention also provides a first-article testing device for micro-lifting of solder paste board to avoid solder damage and prevent pad breakage in SMT reflow ovens, which uses the aforementioned first-article testing method for micro-lifting of solder paste board to avoid solder damage and prevent pad breakage in SMT reflow ovens. The specific structure is the aforementioned automatic testing equipment.

[0019] Using the above-mentioned solution, this invention provides a first-piece testing method and device for micro-lifting of solder paste board before SMT reflow to avoid solder damage to pads. By clamping and placing components in the same coordinate system, the positioning accuracy of component placement is maximized, preventing defects caused by the testing process. The testing process involves only a micro-lift, with a height of only 0.3-1.0mm, which effectively prevents board defects caused by flying components. The components are completely detached from the solder paste during the testing process, ensuring accurate and reliable testing. The probe body's clamping width is elastically adjustable during the testing process to prevent damage to components, ensuring safety and reliability. When the probe is lowered during testing, the Z-axis can elastically float and provide early warning to prevent false testing and overvoltage damage to components or the PCB board, ensuring precise control. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the solder paste board.

[0021] Figure 2 This is a schematic diagram of an embodiment of the automatic testing equipment of the present invention.

[0022] Figure 3 A schematic diagram of an embodiment of the test needle assembly of the present invention.

[0023] Figure 4 This is a schematic diagram of the structure at the positions of the Z-axis floating unit and the two X-axis floating units of the present invention. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] Please see Figures 2-4 This invention provides a first-piece testing method for micro-lifting of solder paste board to avoid solder damage to pads before SMT reflow oven, comprising the following steps: S1: Position and install the PCBA board to be tested onto the test fixture to achieve precise and secure fixation of the PCBA board; run the automatic testing equipment to test the PCBA board to be tested; the automatic testing equipment includes a test probe assembly 10 for clamping components, the test probe assembly 10 includes: a Z-axis lifting assembly 16, a rotating assembly 15, two probe bodies 11, two sets of probe drive assemblies 14, two Z-axis floating units 13, two X-axis floating units 12, and a ranging unit 17. The rotating assembly 15 is mounted on the Z-axis lifting assembly 16 and can achieve Z-axis movement under the drive of the Z-axis lifting assembly 16. Both of the probe drive assemblies 14 are mounted on... The rotating assembly 15 is rotated under its drive. The two probe bodies 11 are respectively connected to the two corresponding probe driving assemblies 14. The two probe bodies 11 can move closer or further apart under the drive of the two probe driving assemblies 14. Each probe body 11 is connected to a Z-axis floating unit 13 and an X-axis floating unit 12. The Z-axis floating unit 13 and the X-axis floating unit 12 are respectively used to adjust the Z-axis floating amount and X-axis floating amount of the corresponding probe body 11. The ranging unit 17 is connected to the Z-axis lifting assembly 16 and is used to detect the distance to the component under test on the solder paste board below.

[0026] S2: Scan the height of each component under test on the PCBA board to obtain the height data of each component under test; and send the obtained height data of each component under test to the automatic testing equipment.

[0027] S3: The automatic testing equipment calculates the test clamping height of the corresponding component under test based on the pre-stored clamping depth parameters of components with different package sizes and the solder paste thickness parameters on the PCBA board surface.

[0028] S4: The automatic testing equipment controls the probe body 11 to run to the calculated test clamp height position, and drives the probe to close to clamp and fix the test component according to the preset clamping force corresponding to the package size of different components under test.

[0029] S5: The probe body 11 is driven by the Z-axis lifting assembly 16 to lift the clamped component under test by 0.3-1.0mm, so that the component under test is separated from the solder paste layer on the PCBA board, thus preventing poor electrical connection problems such as solder bridges and solder bridging between the component under test and the solder paste layer.

[0030] S6: The automatic test equipment starts the electrical test module to read the test values ​​of the component under test. After the test values ​​stabilize, the probe body 11 is driven by the Z-axis lifting component 16 to reset the component under test and place it in the original installation position on the PCBA board.

[0031] S7: Delay for a preset duration, wait for the test component to form a stable bond with the solder paste on the PCBA board, then control the probe body 11 to open and lift and reset.

[0032] S8: Complete the testing of all components under test on the PCBA board in sequence.

[0033] Since the electronic components do not affect the solder paste or the pads underneath it during the lifting and re-attaching process, the pads remain intact after testing, and the solder paste is not carried away. Therefore, there will be no product defects such as open solder joints or cold solder joints after subsequent SMT reflow.

[0034] The automatic testing equipment includes a height detection component 20 that can detect the height value of each component under test on the solder paste board. In step S2, the height value of each component under test on the solder paste board is detected by the automatic testing equipment.

[0035] In this embodiment, the ranging unit 17 is a dot matrix laser sensing device, and the height detection component 20 is a 3D camera device.

[0036] The automated testing equipment also includes a test follow-up camera assembly 30, used to capture images of the clamping position of the probe body 11 during testing.

[0037] This invention precisely achieves complete separation of electronic components from the PCB board and solder paste. After repeated verification and testing, the above test structure was developed specifically for solder paste board testing. A 3D camera device and a dot-matrix laser sensor are responsible for identifying the height and dimensions of the electronic components and the PCB board. The probe body accurately grips the electronic components based on the height position acquired by the 3D camera device or the dot-matrix laser sensor. The Z-axis floating unit and X-axis floating unit are mainly used to adjust the clamping elasticity of the probe body to prevent damage to the components, while also ensuring that the components are returned to their original position after testing to prevent material from being carried away.

[0038] This invention also provides a first-article testing device for micro-lifting of solder paste board to avoid solder damage and prevent pad breakage in SMT reflow ovens, which uses the aforementioned first-article testing method for micro-lifting of solder paste board to avoid solder damage and prevent pad breakage in SMT reflow ovens. The specific structure is the aforementioned automatic testing equipment.

[0039] In summary, this invention provides a first-article testing method and apparatus for micro-lifting of solder paste board before SMT reflow to avoid solder damage to pads. By clamping and placing components at the same coordinates, the positioning accuracy of component placement is maximized, preventing defects caused by the testing process. The testing process involves only a micro-lift, with a height of only 0.3-1.0mm, effectively preventing board defects caused by flying components. The components are completely detached from the solder paste during the testing process, ensuring accurate and reliable testing. The probe body's clamping width is elastically adjustable during the testing process to prevent damage to components, ensuring safety and reliability. When the probe is lowered during testing, the Z-axis can elastically float and provide early warning, preventing false testing and overvoltage damage to components or the PCB board, ensuring precise control.

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A first-article testing method for slightly lifting solder paste board before SMT reflow oven to avoid solder damage to solder pads, characterized in that, Includes the following steps: S1: Position and install the PCBA board to be tested on the test fixture, and run the automatic test equipment to test the PCBA board to be tested; The automatic testing equipment includes a test probe assembly for holding components. The test probe assembly includes: a Z-axis lifting assembly, a rotating assembly, two probe bodies, two sets of probe drive assemblies, two Z-axis floating units, two X-axis floating units, and a ranging unit. The rotating assembly is mounted on the Z-axis lifting assembly and can move along the Z-axis under the drive of the Z-axis lifting assembly. The two probe drive assemblies are both mounted on the rotating assembly and can rotate under the drive of the rotating assembly. The two probe bodies are respectively connected to the two corresponding probe drive assemblies. The two probe bodies can move closer or further away under the drive of the two probe drive assemblies. Each probe body is connected to a Z-axis floating unit and an X-axis floating unit. The Z-axis floating unit and the X-axis floating unit are used to adjust the Z-axis floating amount and X-axis floating amount of the corresponding probe body, respectively. The ranging unit is connected to the Z-axis lifting assembly and is used to detect the distance to the component under test on the solder paste board below. S2: Scan the height of each component under test on the PCBA board to obtain the height data of each component under test; and send the obtained height data of each component under test to the automatic testing equipment. S3: The automatic testing equipment calculates the test clamping height of the corresponding component based on the pre-stored clamping depth parameters of components with different package sizes and the solder paste thickness parameters on the PCBA board surface. S4: The automatic testing equipment controls the probe body to run to the calculated test clamp height position, and drives the probe to close to clamp and fix the test component according to the preset clamping force corresponding to the package size of different test components. S5: The probe body is driven by the Z-axis lifting assembly to lift the clamped component under test by 0.3-1.0mm, so that the component under test is separated from the solder paste layer on the PCBA board. S6: The automatic test equipment starts the electrical test module to read the test values ​​of the component under test. After the test values ​​stabilize, the probe body is driven by the Z-axis lifting component to reset the component under test and place it in the original installation position on the PCBA board. S7: Delay preset duration, wait for the test component to form a stable bond with the solder paste on the PCBA board, then control the probe body to open and lift to reset.

2. The first article testing method for SMT reflow solder paste board micro-lifting to avoid solder damage to pads according to claim 1, characterized in that, Also includes: S8: Complete the testing of all components under test on the PCBA board in sequence.

3. The first article testing method for SMT reflow solder paste board micro-lifting to avoid solder damage to pads according to claim 1, characterized in that, The automatic testing equipment includes a height detection component that can detect the height value of each component under test on the solder paste board. In step S2, the height value of each component under test on the solder paste board is detected by the automatic testing equipment.

4. The first article testing method for SMT reflow solder paste board micro-lifting to avoid solder damage to pads according to claim 1, characterized in that, The height detection component is a dot matrix laser sensor, a linear scanning laser sensor, or a 3D camera.

5. The first article testing method for SMT reflow solder paste board micro-lifting to avoid solder damage to pads according to claim 1, characterized in that, The ranging unit is a dot matrix laser sensing device, a linear scanning laser sensing device, or a 3D camera device.

6. The first article testing method for SMT reflow solder paste board micro-lifting to avoid solder damage to pads according to claim 1, characterized in that, The automated testing equipment also includes a test follow-up camera assembly for capturing images of the clamping position of the probe body during testing.

7. A first-piece testing device for micro-lifting of solder paste board before SMT reflow oven to avoid solder damage to solder pads, characterized in that, The first article test was conducted using the first article test method for micro-lifting of SMT solder paste board to avoid solder damage to pads as described in any one of claims 1-6.

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