A flying probe machine minimum test size determination method, device and system

Abstract

This invention provides a method, apparatus, and system for determining the minimum test size of a flying probe testing machine. The method first determines the systematic and random deviations of the moving screw and target positioning accuracy in the flying probe testing device based on a moving screw and target positioning test. Then, it determines the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe testing device based on repeated probe drop tests. Finally, based on the systematic and random deviations of the moving screw and target positioning accuracy and the vertical drop accuracy of the test probe, and using an accuracy prediction model, the minimum test size of the flying probe testing machine is determined. This allows for a direct prediction of the minimum size of the solder pads that the current flying probe testing device can test, preventing frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient testing accuracy of the flying probe testing device. It also reduces testing time extended by manual intervention and improves the testing efficiency of the flying probe testing device.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board testing technology, and in particular to a method, apparatus and system for determining the minimum test size of a flying probe tester. Background Technology

[0002] With the increasing complexity and miniaturization of electronic products, the production and testing processes of circuit boards face increasingly higher demands. In the production process of electronic products, the reliability and stability of circuit boards directly affect the quality of the final product. Therefore, circuit board testing has become one of the key links in the production process. Flying probe testing technology, as a fixture-free, fast, and efficient testing method, is gradually gaining widespread application. However, the testing efficiency of existing flying probe testing technologies is relatively low. Summary of the Invention

[0003] This invention provides a method, apparatus, and system for determining the minimum test size of a flying probe tester, in order to improve the testing efficiency of flying probe testing.

[0004] According to one aspect of the present invention, a method for determining the minimum test size of a flying probe tester is provided, characterized in that it is executed by a flying probe test device, the flying probe test device comprising an image acquisition module, a moving lead screw, and a test probe, wherein the image acquisition module and the test probe are both disposed opposite to the test surface of the circuit board under test, and the moving lead screw is linked to the test probe, the method comprising: The systematic and random deviations of the accuracy of the moving screw in the target-grabbing machine were determined based on the positioning test of the moving screw target. The systematic and random biases of the vertical drop accuracy of the test probe in the flying probe machine were determined based on repeated needle drop tests. The minimum test size of the flying needle machine is determined based on the systematic and random deviations of the moving lead screw's accuracy in moving and grasping the target, the systematic and random deviations of the vertical drop accuracy of the test probe, and the accuracy prediction model.

[0005] Optionally, the accuracy prediction model is as follows: ; in, This is the minimum test size for the flying probe machine. This refers to the systematic deviation in the target-grabbing accuracy of the lead screw movement. To test the systematic deviation of the probe's vertical drop accuracy. This refers to the random deviation in the target-grabbing accuracy of the lead screw movement. To test the random deviation of the vertical drop accuracy of the probe.

[0006] Optionally, before determining the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's accuracy in moving the target and the systematic and random deviations of the test probe's vertical drop accuracy, and based on an accuracy prediction model, the method further includes: The accuracy prediction model is constructed by performing a first-order linear fit on at least some of the relevant factors of the minimum test size of the flying needle machine, wherein the relevant factors include the target grabbing accuracy of the image acquisition module, the target grabbing accuracy of the moving lead screw, the vertical drop accuracy of the test probe, and the needle diameter accuracy of the test probe.

[0007] Optionally, the systematic and random deviations of the moving screw's accuracy in locating the target are determined based on the positioning test of the moving screw, including: Select at least one set of alignment optical points on the circuit board under test; The moving lead screw moving target positioning test parameters are set, wherein the moving lead screw moving target positioning test parameters include the number of moving lead screw moving target positioning tests; The coordinates of the alignment optical point were measured multiple times; The systematic and random deviations of the moving lead screw's target-grabbing accuracy are calculated based on the coordinates of the alignment optical points.

[0008] Optionally, the systematic and random biases of the vertical drop accuracy of the test probe are determined based on the repeated drop test, including: Select at least one pin drop test point on the circuit board under test; Set the number of times the test probe is dropped vertically; Measure the radius of the circumcircle of the area marked by the needle marks formed by multiple vertical drops of the test probe; The systematic and random deviations of the vertical drop accuracy of the test probe are calculated based on the radius of the circumcircle.

[0009] Optionally, before determining the systematic and random deviations of the accuracy of the moving lead screw in the flying needle machine for moving the target based on the positioning test of the moving lead screw, the following steps are also included: The device parameters of the flying probe testing device are set; wherein, the device parameters include the recognition time of the image acquisition module, the pulse parameters of the moving lead screw servo, and the Z-axis motor parameters of the test probe.

[0010] Optionally, after determining the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's accuracy in moving the target and the systematic and random deviations of the test probe's vertical drop accuracy, and based on an accuracy prediction model, the method further includes: The minimum test size of the flying needle machine was verified through a minimum size verification test.

[0011] Optionally, the minimum test size of the flying needle machine is verified through a minimum size verification test, including: Determine the dimensions of the pads to be tested on the circuit board; Perform multiple vertical drops of the probe and record the number of times the flying probe machine pauses and reports an error. The minimum test size of the flying needle machine is verified based on the number of pauses and error reports of the flying needle machine.

[0012] According to another aspect of the present invention, a minimum test size determination device for a flying probe machine is provided, the device comprising: The first determining module is used to determine the systematic and random deviations of the moving screw target positioning accuracy based on the moving screw target positioning test. The second determining module is used to determine the systematic and random deviations of the vertical drop accuracy of the test probe based on the repeated needle drop test. The minimum test size determination module for the flying needle machine is used to determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's accuracy in moving and grasping the target, and the systematic and random deviations of the vertical drop accuracy of the test probe, and based on an accuracy prediction model.

[0013] According to another aspect of the present invention, a minimum test size determination system for a flying probe tester is provided. The system includes a flying probe test device and the minimum test size determination device for a flying probe tester as described in claim 9. The flying probe test device includes an image acquisition module, a moving lead screw, and a test probe. The image acquisition module and the test probe are both disposed opposite to the test surface of the circuit board under test. The moving lead screw is linked to the test probe. The minimum test size determination device for a flying probe tester is used to determine the minimum test size of the flying probe tester based on the flying probe test device.

[0014] The method for determining the minimum test size of the flying probe tester in this invention first determines the systematic and random deviations of the moving screw and target positioning accuracy in the flying probe tester based on the moving screw and target positioning test. Then, it determines the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe tester based on the repeated drop test. Finally, based on the systematic and random deviations of the moving screw and target positioning accuracy and the vertical drop accuracy of the test probe, and based on the accuracy prediction model, the minimum test size of the flying probe tester is determined. This method can intuitively predict the minimum size of the solder pads that the current flying probe tester can test. Therefore, it can select a flying probe tester with appropriate accuracy based on the matching degree between the minimum test size and the solder pad size of the circuit board under test, preventing frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient test accuracy of the flying probe tester. This reduces the test time extended by manual intervention and improves the test efficiency of the flying probe tester.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a method for determining the minimum test size of a flying needle machine according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a flying probe testing device provided in an embodiment of the present invention; Figure 3 This is another method for determining the minimum test size of a flying needle machine provided in this embodiment of the invention; Figure 4 This is a schematic diagram of the circuit board under test provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the needle marks formed by repeated needle dropping tests provided in an embodiment of the present invention; Figure 6 This is yet another method for determining the minimum test size of a flying needle machine provided by an embodiment of the present invention; Figure 7 This is a comparison diagram of the pulse parameters of the moving lead screw servo before and after setting, provided in an embodiment of the present invention. Figure 8 This is a comparison chart of various deviations before and after setting the equipment parameters of the flying needle testing device according to an embodiment of the present invention; Figure 9 This is a schematic diagram of a device for determining the minimum test size of a flying needle machine, provided in an embodiment of the present invention. Detailed Implementation

[0018] 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.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 the embodiments of the invention described herein can be implemented 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.

[0020] This invention provides a method for determining the minimum test size of a flying probe tester, which is used to determine the minimum pad size that the flying probe tester can stably detect, thereby determining the continuity of the circuit board network under test. This method for determining the minimum test size of a flying probe tester is executed by the flying probe test device. Figure 1 This is a flowchart illustrating a method for determining the minimum test size of a flying probe machine, provided by an embodiment of the present invention. Figure 2 This is a schematic diagram of a flying probe testing device provided in an embodiment of the present invention, with reference to... Figure 1 and Figure 2 The method for determining the minimum test size of the flying probe machine is executed by the flying probe testing device, which includes an image acquisition module 10, a moving lead screw 20 and a test probe 30. The image acquisition module 10 and the test probe 30 are both set opposite to the test surface of the circuit board 40 under test, and the moving lead screw 20 is linked with the test probe 30.

[0021] Methods for determining the minimum test size of a flying probe machine include: S110. Determine the systematic and random deviations of the accuracy of the moving screw in the flying needle machine based on the moving screw target positioning test.

[0022] Specifically, the systematic deviation of the moving lead screw's accuracy in the target-grabbing process refers to the fixed error caused by mechanical manufacturing errors or installation and calibration problems. The random error refers to the unpredictable and variable error caused by factors such as environmental fluctuations or measurement noise. By conducting positioning tests on the moving lead screw, the coordinate errors of the preset position during multiple positioning processes can be determined. Therefore, the magnitude of the systematic and random deviations of the moving lead screw's accuracy in the flying needle machine can be determined based on these coordinate errors.

[0023] S120. Determine the systematic and random deviations of the vertical drop accuracy of the test probe in the flying needle machine based on the repeated needle drop test.

[0024] Specifically, the systematic deviation of the vertical drop accuracy of the test probe refers to the fixed deviation of the vertical drop caused by inherent factors such as the verticality calibration error of the test probe or the return clearance of the drive motor. The random deviation of the vertical drop accuracy of the test probe is the unpredictable deviation during the vertical drop process caused by accidental factors such as unevenness of the test plate surface, contact vibration, or environmental disturbance. By repeating the drop test, the distance error of the preset position in multiple vertical drops of the test probe can be determined, and thus the magnitude of the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe machine can be determined based on the distance error.

[0025] S130. Determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving screw's accuracy in moving the target and the systematic and random deviations of the vertical falling accuracy of the test probe, and based on the accuracy prediction model.

[0026] Specifically, the accuracy prediction model is derived by performing first-order linear correlation on relevant factors based on a univariate linear regression model. By combining the systematic and random deviations of the moving lead screw's target-grabbing accuracy and the vertical drop accuracy of the test probe with the accuracy prediction model, the minimum test size of the flying probe tester can be obtained. This allows for a direct prediction of the minimum pad size that the current flying probe testing device can test. Therefore, based on the matching degree between the minimum test size and the pad size of the circuit board under test, a flying probe testing device with appropriate accuracy can be selected. This prevents frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient testing accuracy of the flying probe testing device, reduces testing time extended by manual intervention, and improves the testing efficiency of the flying probe testing device.

[0027] The method for determining the minimum test size of the flying probe tester in this invention first determines the systematic and random deviations of the moving screw and target positioning accuracy in the flying probe tester based on the moving screw and target positioning test. Then, it determines the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe tester based on the repeated drop test. Finally, based on the systematic and random deviations of the moving screw and target positioning accuracy and the vertical drop accuracy of the test probe, and based on the accuracy prediction model, the minimum test size of the flying probe tester is determined. This method can intuitively predict the minimum size of the solder pads that the current flying probe tester can test. Therefore, it can select a flying probe tester with appropriate accuracy based on the matching degree between the minimum test size and the solder pad size of the circuit board under test, preventing frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient test accuracy of the flying probe tester. This reduces the test time extended by manual intervention and improves the test efficiency of the flying probe tester.

[0028] Optional accuracy prediction models are as follows: ; in, This is the minimum test size for the flying probe machine. The systematic deviation of the moving lead screw in the target-grabbing accuracy, To test the systematic deviation of the probe's vertical drop accuracy. This refers to the random deviation in the accuracy of the target-grabbing movement caused by the moving lead screw. To test the random deviation of the vertical drop accuracy of the probe.

[0029] Specifically, The equipment standard deviation in the accuracy prediction model is 4 times the equipment standard deviation, which can improve the accuracy of the accuracy prediction model.

[0030] Figure 3 Another method for determining the minimum test size of a flying needle machine provided in this embodiment of the invention, refer to... Figure 3 The methods for determining the minimum test size of a flying needle tester include: S210. Construct an accuracy prediction model by performing first-order linear fitting on at least some of the relevant factors of the minimum test size of the flying probe machine, wherein the relevant factors include the target grabbing accuracy of the image acquisition module, the target grabbing accuracy of the moving lead screw, the vertical drop accuracy of the test probe, and the needle diameter accuracy of the test probe.

[0031] Specifically, based on the principle of flying probe testing, the testing process is divided into four steps: aligning and calibrating the circuit board under test; moving the lead screw to control the test probe to move along the X or Y axis until it reaches above the pads of the circuit board under test; the test probe falling along the Z axis; and the test probe contacting the pads of the circuit board under test to complete the test. The alignment and calibration step involves four relevant factors: the target-grabbing accuracy of the image acquisition module, the target-grabbing accuracy of the moving lead screw, the vertical falling accuracy of the test probe, and the tip diameter accuracy of the test probe. Aside from factors inherent to the flying probe testing device itself, the moving screw's target-grabbing accuracy and the vertical drop accuracy of the test probe are strongly correlated factors in flying probe testing. A first-order linear fitting model is constructed using a univariate linear regression model to fit this strongly correlated factor to the minimum test size of the flying probe machine. Based on this accuracy prediction model, the minimum size of the solder pads that the current flying probe machine can test is predicted. This allows for the selection of a flying probe testing device with appropriate accuracy based on the matching degree between the minimum size and the solder pads of the circuit board under test. This prevents frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient testing accuracy, thus improving the testing efficiency of the flying probe testing device. For example, the image acquisition module can be a CCD camera.

[0032] S220. Determine the systematic and random deviations of the accuracy of the moving screw in the flying needle machine based on the moving screw target positioning test.

[0033] S230. Determine the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe machine based on the repeated needle drop test.

[0034] S240. Determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving screw's accuracy in moving the target and the systematic and random deviations of the vertical drop accuracy of the test probe, and based on the accuracy prediction model.

[0035] This invention constructs an accuracy prediction model by performing first-order linear fitting on at least some of the relevant factors of the minimum test size of the flying probe tester. Based on the accuracy prediction model, it predicts the minimum size of the solder pads that the current flying probe tester can test. This allows for the selection of a flying probe tester with appropriate accuracy based on the matching degree between the minimum size and the solder pads of the circuit board under test. This prevents frequent test probe misalignment errors and misjudgments or omissions due to insufficient test accuracy of the flying probe tester, thereby improving the test efficiency of the flying probe tester.

[0036] Optionally, the systematic and random deviations of the moving screw's accuracy in locating the target are determined based on the positioning test of the moving screw, including: Select at least one set of alignment optical points 50 on the circuit board under test; Set the moving lead screw moving target positioning test parameters, where the moving lead screw moving target positioning test parameters include the number of moving lead screw moving target positioning tests; The coordinates of the alignment optical point 50 were measured multiple times; The systematic and random deviations of the moving lead screw's accuracy in moving the target are calculated based on the coordinates of the alignment optical point 50.

[0037] Specifically, Figure 4 This is a schematic diagram of the circuit board under test provided in an embodiment of the present invention, with reference to... Figure 4 The alignment optical point is located at the edge of the circuit board under test, which avoids occupying the effective wiring area and improves alignment accuracy. An unobstructed and clear alignment optical point is selected on the circuit board under test, and the theoretical coordinate parameters of the alignment optical point 50 are recorded. The number of times the moving lead screw moves to the target for positioning is set in the controller of the flying probe testing device. After multiple moving lead screw positioning tests, the coordinate file of the alignment optical point 50 is output. The actual coordinates of each target positioning are extracted from the output coordinate file of the alignment optical point 50. Combined with the theoretical coordinate parameters of the alignment optical point 50, the difference between the actual movement distance and the theoretical movement distance of the moving lead screw after each positioning is calculated. Simultaneously, the distance between the actual positions of the alignment optical points in multiple positioning tests is measured, and all measured distance data are recorded. By statistically analyzing the processed test data, the systematic and random deviations of the flying probe testing machine's moving lead screw positioning are calculated.

[0038] Optionally, the systematic and random biases of the vertical drop accuracy of the test probe are determined based on the repeated drop test, including: Select at least one pin drop test point on the circuit board under test; Set the number of times the test probe is dropped vertically; Measure the radius R of the circumcircle of the area marked by the needle marks formed by multiple vertical drops of the test probe; The systematic and random deviations of the vertical drop accuracy of the test probe are calculated based on the radius of the circumcircle.

[0039] Specifically, Figure 5 This is a schematic diagram of the needle marks formed by repeated needle dropping tests provided in an embodiment of the present invention, with reference to... Figure 5 On the circuit board under test, select a flat and unobstructed target point as the pin drop test point. Then, set the number of times the test probe falls vertically in the controller of the flying probe test device. The radius R of the circumcircle of the pin mark area formed by the multiple vertical drops of the test probe is the radius of the pin mark deviation. Analyze and organize the radius R of the circumcircle of the pin mark area formed by the multiple vertical drops of the test probe, and then calculate the systematic deviation and random deviation of the vertical drop accuracy of the test probe.

[0040] Figure 6 Another method for determining the minimum test size of a flying needle machine provided in this embodiment of the invention, refer to Figure 6 The methods for determining the minimum test size of a flying needle tester include: S310. Set the equipment parameters of the flying probe testing device; the equipment parameters include the recognition time of the image acquisition module, the pulse parameters of the moving lead screw servo, and the Z-axis motor parameters of the test probe. Figure 7 This is a comparison chart showing the pulse parameters of the moving lead screw servo before and after setting them, as provided in an embodiment of the present invention.

[0041] For details, please refer to Figure 6 and Figure 7 The recognition time of the image acquisition module is the time from when the CCD camera starts recognizing the image after receiving the positioning command from the machine to the next action, which can be a driving action, a testing action, or a processing action.

[0042] The pulse parameters of the moving lead screw servo are such that a certain pulse distance is sent in advance before the moving lead screw reaches the target position to issue a positioning command. While the moving lead screw completes the remaining pulse distance, it can be synchronized with the recognition of the image acquisition module or the falling of the test probe, which can shorten the waiting time of the flying probe test device.

[0043] The Z-axis motor parameters of the test probe control the acceleration coefficient during the Z-axis descent. A larger acceleration coefficient results in a smaller descent acceleration. At the same height, increasing the Z-axis motor parameters prolongs the test probe's descent time. Table 1 shows the data for various deviations before and after setting the equipment parameters of the flying probe testing device. Figure 8 This is a comparison chart of various deviations before and after setting the equipment parameters of the flying probe testing device according to an embodiment of the present invention. Figure 8 Increasing the recognition time of the image acquisition module and decreasing the pulse parameters of the moving lead screw servo lengthens the overall alignment time of the image acquisition module. This avoids the shaking effect caused by momentary vibrations, reduces random deviations in the alignment accuracy of the moving lead screw, and thus improves the target-grabbing accuracy. Increasing the Z-axis motor parameters can reduce the systematic deviation of the vertical drop accuracy of the test probe.

[0044] For example, the recognition time of the image acquisition module is adjusted from 300ms to 400ms, the pulse parameter of the moving lead screw servo is adjusted from 20 pulses to 5 pulses, and the Z-axis motor parameter of the test probe is changed from 500 to 800.

[0045] S320. Determine the systematic and random deviations of the accuracy of the moving screw in the flying needle machine based on the moving screw target positioning test.

[0046] S330. Determine the systematic and random deviations of the vertical drop accuracy of the test probe in the flying probe machine based on the repeated needle drop test.

[0047] S340. Determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving screw's accuracy in moving the target and the systematic and random deviations of the vertical drop accuracy of the test probe, and based on the accuracy prediction model.

[0048] S350: The minimum test size of the flying needle machine is verified through the minimum size verification test.

[0049] Specifically, the minimum size verification test verifies the correctness of the minimum test size of the flying probe machine and the reliability of the method for determining the minimum test size of the flying probe machine.

[0050] In this embodiment of the invention, the equipment parameters of the flying probe testing device are first set, then the minimum test size of the flying probe machine is determined, and finally the minimum test size of the flying probe machine is verified through a minimum size verification test. Increasing the recognition time of the image acquisition module and decreasing the pulse parameters of the moving lead screw servo can reduce the random deviation of the moving lead screw's target positioning accuracy. Increasing the Z-axis motor parameters can reduce the systematic deviation of the vertical drop accuracy of the test probe, thereby improving the reliability and testing efficiency of the method for determining the minimum test size of the flying probe machine.

[0051] Optionally, the minimum test size of the flying probe machine is verified through a minimum size verification test, including: Determine the dimensions of the pads to be tested on the circuit board; Perform multiple vertical drops of the probe and record the number of times the flying probe machine pauses and reports an error. The minimum test size of the flying probe machine is verified based on the number of pauses and error reports.

[0052] Specifically, the minimum measurement dimensions of probes #7 and #8 were predicted using the minimum test dimension determination method, and the minimum test dimension of probe #8 was verified through minimum dimension testing. Table 2 shows the predicted minimum measurement dimension data for probes #7 and #8, and Table 3 shows the minimum test dimension data for probe #8 determined by the minimum dimension verification test. Specifically, the dimensions of the pads to be tested on the circuit board must be clearly defined. For example, if the pad is circular, the diameter of the pad must be defined; if the pad is rectangular, the length of the shorter side of the pad must be defined. The number of pauses and error reports by the flying probe tester reflects the minimum test size that the flying probe tester can measure. A decrease in the number of pauses and error reports indicates a decrease in the number of times the test probe is misaligned, which can reduce manual intervention, thereby reducing the flying probe test time and improving the test efficiency.

[0053] Table 2 shows that after setting the equipment parameters, the predicted minimum test sizes for machines 7 and 8, based on the minimum test size determination method for flying probe machines, are 79 μm and 91 μm, respectively. Table 3 shows that, through minimum size verification testing, machine 8 only experiences a pause and error when the pad size is less than or equal to 89 μm, verifying the reliability of the minimum test size determination method for flying probe machines.

[0054] After setting the equipment parameters for machine No. 8, machine No. 8 can normally test pads with a diameter greater than 100μm for both circular and rectangular pads. The pause rate of the flying probe testing device is 0, indicating that the minimum test size capability of machine No. 8 has been improved. At the same time, the time saved by reducing the number of pauses of machine No. 8 is greater than the time extended by manually adjusting the equipment parameters, thus improving the testing accuracy and efficiency of the flying probe testing device.

[0055] This invention provides a device for determining the minimum test size of a flying probe machine. Figure 9 This is a schematic diagram of a device for determining the minimum test size of a flying needle machine, provided in an embodiment of the present invention. (Refer to...) Figure 9 The device for determining the minimum test size of the flying needle machine includes: The first determining module 410 is used to determine the systematic and random deviations of the moving screw target positioning accuracy based on the moving screw target positioning test. The second determining module 420 is used to determine the systematic and random deviations of the vertical drop accuracy of the test probe based on the repeated needle drop test. The minimum test size determination module 430 for the flying needle machine is used to determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving screw's accuracy in moving the target and the systematic and random deviations of the vertical drop accuracy of the test probe, and based on an accuracy prediction model.

[0056] This invention, through the cooperation of various modules, achieves the determination of the minimum test size of the flying probe machine by combining the systematic and random deviations of the moving lead screw's target-grabbing accuracy and the vertical drop accuracy of the test probe with an accuracy prediction model. This allows for a direct prediction of the minimum size of the solder pads that the flying probe machine can test. Consequently, a flying probe testing device with appropriate accuracy can be selected based on the matching degree between the minimum size and the solder pads of the circuit board under test. This prevents frequent test probe misalignment errors and misjudgments / missed judgments due to insufficient testing accuracy, reduces the testing time extended by manual intervention, and improves the testing efficiency of the flying probe machine.

[0057] In some embodiments, the accuracy prediction model is as follows: ; in, This is the minimum test size for the flying probe machine. This refers to the systematic deviation in the target-grabbing accuracy of the lead screw movement. To test the systematic deviation of the probe's vertical drop accuracy. This refers to the random deviation in the target-grabbing accuracy of the lead screw movement. To test the random deviation of the vertical drop accuracy of the probe.

[0058] In some embodiments, the flying probe minimum test size determination device further includes: The accuracy prediction model construction module is used to construct an accuracy prediction model by performing first-order linear fitting on at least some of the relevant factors of the minimum test size of the flying probe machine. The relevant factors include the target grabbing accuracy of the image acquisition module, the target grabbing accuracy of the moving lead screw, the vertical drop accuracy of the test probe, and the needle diameter accuracy of the test probe.

[0059] In some embodiments, the first determining module includes: The first selection unit is used to select at least one set of alignment optical points on the circuit board under test; The first setting unit is used to set the moving screw moving target positioning test parameters, wherein the moving screw moving target positioning test parameters include the number of moving screw moving target positioning tests; The first measurement unit is used to measure the coordinates of the alignment optical point multiple times; The first calculation unit is used to calculate the systematic and random deviations of the moving lead screw's accuracy in moving the target based on the coordinates of the alignment optical point.

[0060] In some embodiments, the second determining module includes: The second selection unit is used to select at least one pin drop test point on the circuit board under test; The second setting unit is used to set the number of times the test probe falls vertically; The second measurement unit is used to measure the radius of the circumcircle of the needle mark area formed by multiple vertical drops of the test probe; The second calculation unit is used to calculate the systematic and random deviations of the vertical drop accuracy of the test probe based on the radius of the circumscribed circle.

[0061] In some embodiments, the flying probe minimum test size determination device further includes: The equipment parameter setting module is used to set the equipment parameters of the flying probe testing device; among which, the equipment parameters include the recognition time of the image acquisition module, the pulse parameters of the moving lead screw servo, and the Z-axis motor parameters of the test probe.

[0062] In some embodiments, the flying probe minimum test size determination device further includes: The verification module is used to verify the minimum test size of the flying probe machine through a minimum size verification test.

[0063] In some embodiments, the verification module includes: The pad size determination unit is used to determine the size of the pad to be tested on the circuit board; The test recording unit is used to perform multiple vertical drops of the test probe and record the number of times the flying probe machine pauses and reports an error. The verification unit is used to verify the minimum test size of the flying probe machine based on the number of pause error reports from the flying probe machine.

[0064] This invention provides a system for determining the minimum test size of a flying probe tester, including a flying probe testing device and a minimum test size determination device for flying probe testers according to any embodiment. The flying probe testing device includes an image acquisition module, a moving lead screw, and a test probe. The image acquisition module and the test probe are both arranged opposite to the test surface of the circuit board under test. The moving lead screw is linked to the test probe. The minimum test size determination device for flying probe testers is used to determine the minimum test size of the flying probe tester based on the flying probe testing device.

[0065] The minimum test size determination system for flying needle machine in this embodiment of the invention belongs to the same inventive concept as the minimum test size determination device and method for flying needle machine provided in any embodiment of the invention, and has corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the minimum test size determination device and method for flying needle machine in any embodiment of the invention.

[0066] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0067] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for determining the minimum test size of a flying needle tester, characterized in that, Performed by a flying probe testing device, the flying probe testing device includes an image acquisition module, a moving lead screw, and a test probe. The image acquisition module and the test probe are both positioned opposite the test surface of the circuit board under test. The moving lead screw is linked to the test probe. The method includes: The systematic and random deviations of the accuracy of the moving screw in the target-grabbing machine were determined based on the positioning test of the moving screw target. The systematic and random biases of the vertical drop accuracy of the test probe in the flying probe machine were determined based on repeated needle drop tests. The minimum test size of the flying needle machine is determined based on the systematic and random deviations of the moving lead screw's accuracy in moving and grasping the target, the systematic and random deviations of the vertical drop accuracy of the test probe, and the accuracy prediction model.

2. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that: The accuracy prediction model is as follows: ； in, This is the minimum test size for the flying probe machine. This refers to the systematic deviation in the target-grabbing accuracy of the lead screw movement. To test the systematic deviation of the probe's vertical drop accuracy. This refers to the random deviation in the target-grabbing accuracy of the lead screw movement. To test the random deviation of the vertical drop accuracy of the probe.

3. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that, Before determining the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's target-grabbing accuracy and the systematic and random deviations of the test probe's vertical drop accuracy, and based on the accuracy prediction model, the following steps are also included: The accuracy prediction model is constructed by performing a first-order linear fit on at least some of the relevant factors of the minimum test size of the flying needle machine, wherein the relevant factors include the target grabbing accuracy of the image acquisition module, the target grabbing accuracy of the moving lead screw, the vertical drop accuracy of the test probe, and the needle diameter accuracy of the test probe.

4. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that, The systematic and random deviations of the moving screw's accuracy in locating the target were determined based on the positioning test of the moving screw. These deviations include: Select at least one set of alignment optical points on the circuit board under test; The moving lead screw moving target positioning test parameters are set, wherein the moving lead screw moving target positioning test parameters include the number of moving lead screw moving target positioning tests; The coordinates of the alignment optical point were measured multiple times; The systematic and random deviations of the moving lead screw's target-grabbing accuracy are calculated based on the coordinates of the alignment optical points.

5. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that, The systematic and random biases of the vertical drop accuracy of the test probe are determined based on repeated drop tests, including: Select at least one pin drop test point on the circuit board under test; Set the number of times the test probe is dropped vertically; Measure the radius of the circumcircle of the area marked by the needle marks formed by multiple vertical drops of the test probe; The systematic and random deviations of the vertical drop accuracy of the test probe are calculated based on the radius of the circumcircle.

6. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that, Before determining the systematic and random deviations of the accuracy of the moving lead screw in the flying needle machine for moving target positioning based on the moving lead screw moving target positioning test, the following is also included: The device parameters of the flying probe testing device are set; wherein, the device parameters include the recognition time of the image acquisition module, the pulse parameters of the moving lead screw servo, and the Z-axis motor parameters of the test probe.

7. The method for determining the minimum test size of a flying needle machine according to claim 1, characterized in that, After determining the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's target-grabbing accuracy and the systematic and random deviations of the test probe's vertical drop accuracy, and based on the accuracy prediction model, the process further includes: The minimum test size of the flying needle machine was verified through a minimum size verification test.

8. The method for determining the minimum test size of a flying needle machine according to claim 7, characterized in that, The minimum test size of the flying needle machine is verified through a minimum size verification test, including: Determine the dimensions of the pads to be tested on the circuit board; Perform multiple vertical drops of the probe and record the number of times the flying probe machine pauses and reports an error. The minimum test size of the flying needle machine is verified based on the number of pauses and error reports of the flying needle machine.

9. A device for determining the minimum test size of a flying needle machine, characterized in that, include: The first determining module is used to determine the systematic and random deviations of the moving screw target positioning accuracy based on the moving screw target positioning test. The second determining module is used to determine the systematic and random deviations of the vertical drop accuracy of the test probe based on the repeated needle drop test. The minimum test size determination module for the flying needle machine is used to determine the minimum test size of the flying needle machine based on the systematic and random deviations of the moving lead screw's accuracy in moving and grasping the target, and the systematic and random deviations of the vertical drop accuracy of the test probe, and based on an accuracy prediction model.

10. A system for determining the minimum test size of a flying probe machine, characterized in that, The invention includes a flying probe testing device and a flying probe machine minimum test size determination device as described in claim 9. The flying probe testing device includes an image acquisition module, a moving lead screw, and a test probe. The image acquisition module and the test probe are both arranged opposite to the test surface of the circuit board under test. The moving lead screw is linked to the test probe. The flying probe machine minimum test size determination device is used to determine the minimum test size of the flying probe machine based on the flying probe testing device.

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