A probe connector device for PCB board connection testing

Abstract

The application relates to the technical field of PCB connection test, in particular to a probe connector device for PCB connection test, which comprises a data acquisition module and a test control module; the test control module comprises an interface contact quality determination unit used to determine whether the interface contact quality of the test probe and the test position is qualified based on a resistance variation coefficient; a spring strain determination unit used to set a plurality of voltage adjustment coefficients to adjust the control voltage of the piezoelectric ceramic sheet based on the comparison result of a compression state characteristic value and a preset compression state characteristic value; a spring strain correction unit used to determine the position where the interface contact pressure is unqualified based on a temperature abnormal range, to set a plurality of voltage correction coefficients to optimize the voltage adjustment coefficient according to the temperature difference, and a strain threshold adjustment unit used to adjust the preset compression state characteristic value based on the optimization frequency of the voltage correction coefficient. The application improves the interface contact quality of the test probe and the PCB.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PCB board connection test, and particularly relates to a probe connector device for PCB board connection test. BACKGROUND

[0002] In the field of high-precision test of PCB boards, the probe connector device is a core component for realizing electrical connection between a test device and test points of a PCB board. The contact quality between the movable outer conductor and the movable inner conductor of the probe connector device and the interface of the PCB board directly affects the reliability and accuracy of the detection result. In the traditional probe connector device, the movable outer conductor (shielding ring) is in contact with the periphery of the test point of the PCB board through elastic pressure, which is used to isolate external electromagnetic interference; the movable inner conductor (probe) directly presses the test point to realize signal transmission. However, in the long-term test process, the contact quality between the two and the PCB interface is easily affected by multiple factors: first, the spring of the movable outer conductor is caused by material fatigue and plastic deformation, so that the rigidity is attenuated, the pressure fluctuates under the same compression amount, and the contact between the shielding layer and the PCB is tight or loose, which may cause electromagnetic interference coupling (such as high-frequency signal crosstalk) due to insufficient pressure, or scratch the PCB pad due to excessive pressure; second, when the tip of the movable inner conductor (probe) is in contact with the test point of the PCB, the interface is easy to accumulate oxide layer, pollutants or solder residues, which causes the contact resistance to abnormally increase, and then affects the stability of the electrical signal transmission; third, the contact state (such as pressure uniformity and adhesion) between the two and the PCB interface gradually deteriorates with the increase of the test number, which causes the dispersion degree of the repeated test results of the same test point to increase, and finally causes test misjudgment. The above problems are particularly prominent in the test of high-frequency and high-density PCB boards, which seriously restricts the improvement of test efficiency and product yield, and therefore it is urgent to design a probe connector device that can stably guarantee the contact quality between the movable outer conductor and the movable inner conductor and the PCB board interface.

[0003] Chinese patent application publication No. CN102239602A discloses a probe connector connecting a circuit board and a coaxial plug including an axial terminal and a surrounding terminal. The coaxial probe of the probe connector includes a central terminal connected to the circuit board and the axial terminal, and an outer terminal coaxial with the central terminal and connected to the circuit board and the surrounding terminal. The outer terminal includes a cylindrical outer conductor surrounding the central terminal and cooperating with the surrounding terminal, an anchor formed as a protrusion on a part of an outer surface of the outer conductor by a machining process so that a hole is formed on the part of the outer surface, and a conductive cover covering and closing the hole and electrically connected to the outer conductor. Therefore, the position of the coaxial probe only slightly moves even when the coaxial plug is inserted into or pulled out of the coaxial probe.

[0004] There is also a problem in the prior art that the spring plastic deformation of the active outer conductor and the active inner conductor decreases due to repeated testing, or the interface contact quality of the probe connector and the PCB is poor due to insufficient flatness of the test surface of the PCB, thereby causing low test accuracy. SUMMARY

[0005] To this end, the present application provides a probe connector device for PCB connection testing to overcome the problem in the prior art that the spring plastic deformation of the active outer conductor and the active inner conductor decreases due to repeated testing, or the interface contact quality of the probe connector and the PCB is poor due to insufficient flatness of the test surface of the PCB, thereby causing low test accuracy.

[0006] To achieve the above-mentioned purpose, the present application provides a probe connector device for PCB connection testing, comprising:

[0007] a data acquisition module comprising an infrared acquisition component for acquiring a temperature distribution image of the surface of the PCB, and a strain sensor for acquiring spring deformation;

[0008] a test control module comprising,

[0009] an interface contact quality determination unit for determining a resistance variation coefficient based on a plurality of contact resistances of the test probe and the test position, and determining whether the interface contact quality of the test probe and the test position is qualified according to the resistance variation coefficient;

[0010] a spring strain determination unit for determining a compression state representation value of the outer conductor spring or the inner conductor spring based on the strain value of the strain sensor, and setting a plurality of voltage adjustment coefficients to adjust the control voltage of the piezoelectric ceramic sheet according to the comparison result of the compression state representation value and a preset compression state representation value;

[0011] a spring strain correction unit for determining a temperature abnormal range based on the temperature distribution image, determining that the interface contact pressure of the active outer conductor or the active inner conductor and the test position is unqualified based on the temperature abnormal range, and setting a plurality of voltage correction coefficients to optimize the voltage adjustment coefficient according to the temperature difference between the highest temperature in the temperature abnormal range and a preset temperature;

[0012] a strain threshold adjustment unit for adjusting the preset compression state representation value based on the optimization frequency of the voltage correction coefficient.

[0013] Further, the probe connector device further comprises:

[0014] A test probe comprising an active outer conductor configured to shield a signal, an outer conductor spring configured to allow the active outer conductor to expand and contract, a first piezoelectric ceramic disc coaxially mounted with the outer conductor spring, an active inner conductor coaxially mounted with the active outer conductor to establish an electrical connection, an inner conductor spring configured to allow the active inner conductor to expand and contract, a second piezoelectric ceramic disc coaxially mounted with the inner conductor spring, wherein a steel wire inner portion of the outer conductor spring and the inner conductor spring is embedded with a strain sensor, respectively.

[0015] A probe connection mechanism comprising a first probe connection mechanism and a second probe connection mechanism,

[0016] The first probe connection mechanism comprises a plurality of first single channels configured to place a plurality of the test probes, a first press plate configured to fix the plurality of the first single channels, a first main support embedded with the first press plate to provide rigid support, and a positioning column configured at a bottom of the first main support to align a PCB board and a probe connector.

[0017] The second probe connection mechanism comprises a plurality of second single channels configured to place a plurality of the test probes, a second press plate configured to fix the plurality of the second single channels, a second main support embedded with the second press plate to provide rigid support, and a connecting bolt configured at a bottom of the second main support to fix the PCB board and the probe connector.

[0018] Further, the interface contact quality determination unit determines that the interface contact quality is unqualified based on a comparison result that the resistance variation coefficient is greater than a preset resistance variation coefficient.

[0019] The interface contact quality determination unit determines that the interface contact quality is qualified based on a comparison result that the resistance variation coefficient is less than or equal to the preset resistance variation coefficient.

[0020] Further, the spring strain determination unit sets a plurality of voltage adjustment coefficients based on a comparison result of the compression state representation value and a preset representation value under the condition that the interface contact quality is unqualified, to increase the control voltage of the piezoelectric ceramic disc based on the plurality of voltage adjustment coefficients.

[0021] Further, the spring strain correction unit determines that the interface contact pressure of the active outer conductor and the active inner conductor with the test position is unqualified based on a comparison result that the temperature abnormal range is greater than a first preset range.

[0022] Further, the spring strain correction unit determines that the interface contact pressure of the active outer conductor with the test position is unqualified based on a comparison result that the temperature abnormal range is less than or equal to the first preset range and greater than a second preset range.

[0023] Further, the spring strain correction unit determines that the interface contact pressure of the active inner conductor and the test position is unqualified based on a comparison result that the temperature abnormal range is less than or equal to the second preset range.

[0024] Further, the spring strain correction unit sets a plurality of voltage correction coefficients based on a comparison result that the temperature difference and a preset difference value under the condition that the interface contact pressure is determined to be unqualified, so as to optimize the voltage adjustment coefficient based on the plurality of voltage correction coefficients.

[0025] Further, the strain threshold adjustment unit determines to adjust the preset compression state representation value based on a comparison result that the optimization frequency is greater than a preset frequency.

[0026] Further, the strain threshold adjustment unit sets a plurality of threshold adjustment coefficients based on a frequency difference value of the optimization frequency and the preset frequency, so as to increase the preset compression state representation value according to the plurality of threshold adjustment coefficients.

[0027] Compared with the prior art, the beneficial effects of the present application are that the present application determines the contact resistance of the active outer conductor and the active inner conductor of the test probe to the test position respectively by using the four-probe method to determine the resistance variation coefficient of several contact positions, the core function of the active outer conductor is to realize electromagnetic shielding through a low-impedance connection, and the contact resistance of the active outer conductor to the test point needs to be as small as possible to reduce signal reflection and energy loss at the interface, the core function of the active inner conductor is to realize low-loss transmission of the test signal, and the contact resistance of the probe to the test point needs to be kept small to ensure the integrity of signal transmission, for a probe connector integrated with multiple test probes, the interface contact quality of the probe connector and the PCB board can be determined by the resistance variation coefficient, the smaller the resistance variation coefficient, the better the interface contact quality of the probe connector and the PCB board; for the case of unqualified interface contact quality, the compression state value of the spring of any test probe is determined to determine whether the contact pressure is too small due to the too small compression value of the spring, thereby causing unqualified contact resistance, for the case of too small compression value of the spring, the control voltage of the piezoelectric ceramic sheet is increased to increase the deformation degree of the piezoelectric ceramic sheet, the compression value of the spring is increased to increase the contact pressure of the test probe and reduce the contact resistance; for the case of qualified interface contact quality, the temperature distribution image of the test process is obtained to determine the temperature abnormal range, and it is determined whether the active outer conductor and the PCB board have unqualified interface contact quality, or the active inner conductor and the PCB board have unqualified interface contact quality, or both have unqualified interface contact quality, and the corresponding voltage adjustment coefficient is optimized according to the determined condition to improve the interface contact quality; after the probe connector is tested for many times, the rigidity of the built-in spring may decay, causing the contact pressure provided by the same compression value to be smaller, therefore, a coefficient curve is established according to the historical test process, whether the spring has rigidity decay is determined according to the frequency of the optimized voltage correction coefficient, and the preset compression state value is improved accordingly to further improve the interface contact quality and the test precision.

[0028] Further, the present application determines the position of unqualified interface contact pressure through the temperature abnormal range, under the condition that the interface contact pressure of the active outer conductor and the active inner conductor is unqualified, the temperature of the contact area of the active inner conductor is the highest, and the temperature of the contact area of the active outer conductor is the second highest, and the temperature abnormal range is large and diverges around the active outer conductor; under the condition that the interface contact pressure of the active outer conductor is unqualified, the temperature is mainly concentrated in the contact area of the active outer conductor, and the highest temperature is lower than that under the condition that the interface contact pressure of the active outer conductor and the active inner conductor is unqualified, and the temperature abnormal range is small; under the condition that the interface contact pressure of the active inner conductor is unqualified, the temperature is mainly concentrated in the contact point of the tip of the active inner conductor and the test point, and the temperature abnormal range is the smallest, therefore, the position of unqualified interface contact pressure can be determined through the temperature abnormal range for targeted adjustment, thereby improving the interface contact quality and further improving the test precision. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Structure diagram of test probe for PCB connection test according to an embodiment of the present application;

[0030] Figure 2 Structure diagram of probe connector device for PCB connection test according to an embodiment of the present application;

[0031] Figure 3 Structure block diagram of probe connector device for PCB connection test according to an embodiment of the present application;

[0032] Figure 4 Flow chart for determining whether interface contact quality is qualified according to an embodiment of the present application;

[0033] Figure 5 Enlarged view of part A according to an embodiment of the present application;

[0034] Figure 6 Enlarged view of part B according to an embodiment of the present application;

[0035] In the figure: 1, test probe, 2, connector main body, 3, movable outer conductor, 4, movable inner conductor, 5, outer conductor spring, 6, inner conductor spring, 7, first piezoelectric ceramic sheet, 8, second piezoelectric ceramic sheet, 9, strain sensor, 10, cable, 11, first probe connecting mechanism, 12, second probe connecting mechanism, 13, first single channel, 14, first pressing plate, 15, first main body support, 16, positioning column, 17, second single channel, 18, second pressing plate, 19, second main body support, 20, connecting bolt, 21, cover plate. DETAILED DESCRIPTION

[0036] In order to make the objects and advantages of the present application clearer, the present application will be further described below in conjunction with embodiments. It should be understood that the specific embodiments described herein merely serve the purpose of explaining the present application and are not intended to limit the present application.

[0037] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that the embodiments merely serve the purpose of explaining the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0038] It should be noted that in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings, which is merely for the purpose of description and is not intended to indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0039] Moreover, it needs to be explained that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense and for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] Please refer to Figures 1-6 as shown, Figure 1 is a structural schematic view of a test probe for PCB connection test according to an embodiment of the present application; Figure 2 is a structural schematic view of a probe connector device for PCB connection test according to an embodiment of the present application; Figure 3 is a structural block diagram of a probe connector device for PCB connection test according to an embodiment of the present application; Figure 4 is a flow chart for determining whether the interface contact quality is qualified according to an embodiment of the present application; Figure 5 is an enlarged view of part A according to an embodiment of the present application; Figure 6 is an enlarged view of part B according to an embodiment of the present application.

[0041] The probe connector device for PCB connection test according to an embodiment of the present application comprises:

[0042] a plurality of test probes 1, which comprise a connector body 2, a movable outer conductor 3 arranged inside the connector body 2 for shielding signals, an outer conductor spring 5 connected with the movable outer conductor 3 for allowing the movable outer conductor 3 to stretch and contract, a first piezoelectric ceramic sheet 7 coaxially arranged at an end of the outer conductor spring 5 away from the movable outer conductor 3, a movable inner conductor 4 arranged inside the movable outer conductor 3 and coaxially arranged with the movable outer conductor 3 for establishing electrical connection, an inner conductor spring 6 connected with the movable inner conductor 4 for allowing the movable inner conductor 4 to stretch and contract, and a second piezoelectric ceramic sheet 8 coaxially arranged at an end of the inner conductor spring 6 away from the movable inner conductor 4, wherein the steel wire inside the outer conductor spring 5 and the inner conductor spring 6 is respectively embedded with a strain sensor 9;

[0043] a cable 10 connected with the test probe 1 at an end close to the outer conductor spring 5 for transmitting test signals;

[0044] a probe connecting mechanism, which comprises a first probe connecting mechanism 11 and a second probe connecting mechanism 12,

[0045] The first probe connecting mechanism 11 comprises a plurality of first single channels 13 for placing a plurality of test probes 1, a first pressing plate 14 for fixing the plurality of first single channels 13, a first main support 15 embedded with the first pressing plate 14 for providing rigid support, and a positioning column 16 arranged at the bottom of the first main support 15 for aligning the PCB and the probe connector;

[0046] The second probe connecting mechanism 12 comprises a plurality of second single channels 17 for placing a plurality of test probes 1, a second pressing plate 18 for fixing the plurality of second single channels 17, a second main support 19 embedded with the second pressing plate 18 for providing rigid support, and a connecting bolt 20 arranged at the bottom of the second main support 19 for fixing the PCB and the probe connector;

[0047] A bundling mechanism connected to the first probe connecting mechanism 11 and the second probe connecting mechanism 12 comprises a cover plate 21 embedded with the first main support 15 and the second main support 19 respectively for sealing a plurality of cables 10;

[0048] A data acquisition module comprising an infrared acquisition component for acquiring a temperature distribution image of the surface of the PCB, and a strain sensor 9 for acquiring spring deformation;

[0049] A test control module comprising,

[0050] An interface contact quality determination unit for determining a resistance variation coefficient based on a plurality of contact resistances between the test probe 1 and the test position, and determining whether the interface contact quality between the test probe 1 and the test position is qualified according to the resistance variation coefficient;

[0051] A spring strain determination unit for determining a compression state representation value of the outer conductor spring 5 or the inner conductor spring 6 based on the strain value of the strain sensor 9, and setting a plurality of voltage adjustment coefficients to adjust the control voltage of the piezoelectric ceramic sheet according to the comparison result between the compression state representation value and a preset compression state representation value;

[0052] A spring strain correction unit for determining a temperature abnormal range based on the temperature distribution image, determining that the interface contact pressure between the movable outer conductor 3 or the movable inner conductor 4 and the test position is unqualified based on the temperature abnormal range, and setting a plurality of voltage correction coefficients to optimize the voltage adjustment coefficient according to the temperature difference between the highest temperature in the temperature abnormal range and a preset temperature;

[0053] A strain threshold adjustment unit for adjusting the preset compression state representation value based on the optimization frequency of the voltage correction coefficient.

[0054] Specifically, the interface contact quality determination unit determines that the interface contact quality is unqualified based on a comparison result that the resistance variation coefficient is greater than a preset resistance variation coefficient.

[0055] The interface contact quality determination unit determines that the interface contact quality is qualified based on a comparison result that the resistance variation coefficient is less than or equal to the preset resistance variation coefficient.

[0056] Specifically, the inner part of the steel wire of the outer conductor spring 5 and the inner conductor spring 6 is embedded with a strain sensor 9, and the fiber Bragg grating is integrated into the spring steel wire by using precision machining and fiber Bragg grating writing technology. Then the spring steel wire is made into a spring. The specific process includes: using laser micro-machining or electric spark machining to etch a spiral groove on the surface of the spring steel wire, which provides space for the fiber to be embedded, and at the same time, the spring compression strain is transmitted to the fiber Bragg grating through mechanical coupling. The groove depth is 0.13mm-0.3mm, the width is 0.23mm-0.5mm, and the spiral angle is designed according to the compression stroke of the probe, usually 5°-30°. The fiber uses a hollow double-core fiber, and its air cavity structure can reduce the bending loss and adapt to the small curvature of the spring steel wire. At the same time, an ArF excimer laser is used to cooperate with a phase mask to form a periodic refractive index modulation in the fiber core. Finally, low-viscosity epoxy resin such as EPO-TEK 353ND is filled in the groove to embed the fiber Bragg grating and solidify it after embedding, ensuring that the fiber and the steel wire are synchronized in strain. When the spring is compressed during testing, the fiber also experiences axial strain, resulting in a change in the Bragg reflection wavelength. Therefore, the compression strain value of the spring can be calculated according to the Bragg wavelength drift combined with the initial Bragg wavelength and the material properties of the spring steel wire.

[0057] Specifically, the contact resistance value of the outer movable conductor and the inner movable conductor to the test position of the PCB board is measured by using the four-probe method, i.e. the Kelvin four-terminal method, which separates the current line and the voltage line to eliminate the interference of lead resistance and accurately measure the resistance value of each contact point. This is a prior art and will not be described in detail.

[0058] Specifically, the resistance variation coefficient is the percentage of the standard deviation to the average value of several contact resistances, which represents the fluctuation degree of the contact resistance of the test probe 1 to the PCB board. The interface contact quality is required to be stable and consistent, i.e. "low dispersion", which means that the fluctuation of the contact resistance is within an acceptable range, and the repeatability and consistency of the test results are high, and the contact quality is qualified. If the contact quality is poor, it will cause significant fluctuations in the contact resistance, i.e. "high dispersion", which means that the fluctuation of the contact resistance is beyond the normal range, and there are a large number of abnormal contact points, and the test results are unreliable, and the contact quality is unqualified. At this time, the resistance variation coefficient will increase significantly due to the increase of the standard deviation.

[0059] Specifically, the preset resistance variation coefficient is determined based on historical test data of at least 1000 test points with qualified interface contact quality, and the average value and the standard deviation are obtained after cleaning the historical test data, and the percentage of the standard deviation to the average value is determined as the preset resistance variation coefficient, and the optional range is set to [5%, 10%], and the embodiment of the application preferably is 8%.

[0060] Specifically, the spring strain determination unit sets a plurality of voltage adjustment coefficients based on the comparison result of the compression state characteristic value and the preset characteristic value under the condition that the interface contact quality is unqualified, so as to increase the control voltage of the piezoelectric ceramic sheet based on the plurality of voltage adjustment coefficients.

[0061] Specifically, the spring strain determination unit determines to increase the control voltage by a first voltage adjustment coefficient based on the comparison result that the compression state characteristic value is less than a first preset characteristic value.

[0062] The spring strain determination unit determines to increase the control voltage by a second voltage adjustment coefficient based on the comparison result that the compression state characteristic value is greater than or equal to the first preset characteristic value and less than a second preset characteristic value.

[0063] Specifically, the compression state characteristic value is the compression deformation amount of the outer conductor spring 5 or the inner conductor spring 6, and the compression deformation amount of the spring is one-to-one corresponding to the contact pressure of the movable outer conductor 3 or the movable inner conductor 4 and the PCB board, and the preset characteristic value is determined according to the test requirement of the contact pressure, for example, the test contact pressure requirement of the movable outer conductor 3 and the PCB board is 100gf-150gf, and the preset characteristic value value range can be calculated according to the contact pressure requirement value combined with the material rigidity of the spring, which is 2mm-3mm, in the implementation, the second preset characteristic value takes the lower limit 2mm of the preset characteristic value value range, and the first preset characteristic value is 0.8 times of the second preset characteristic value, i.e. 1.6mm, the test contact pressure requirement of the movable inner conductor 4 and the PCB board is 50gf-100gf, and the preset characteristic value value range can be calculated according to the contact pressure requirement value combined with the material rigidity of the spring, which is 1mm-2mm, in the implementation, the second preset characteristic value takes the lower limit 1mm of the preset characteristic value value range, and the first preset characteristic value is 0.8 times of the second preset characteristic value, i.e. 0.8mm.

[0064] Specifically, for the active outer conductor 3, the value range of the first voltage adjustment coefficient is set to [1.4, 1.7], and the embodiment of the application preferably 1.5, and the value range of the second voltage adjustment coefficient is set to [1.1, 1.3], and the embodiment of the application preferably 1.2; for the active inner conductor 4, the value range of the first voltage adjustment coefficient is set to [1.2, 1.4], and the embodiment of the application preferably 1.3, and the value range of the second voltage adjustment coefficient is set to [1.05, 1.19], and the embodiment of the application preferably 1.15.

[0065] It can be understood that increasing the control voltage of the piezoelectric ceramic sheet can increase its deformation, which is mainly based on the physical mechanism of the inverse piezoelectric effect. When a piezoelectric ceramic is subjected to an electric field, its internal lattice structure is polarized and reorganized, resulting in mechanical deformation. Increasing the control voltage directly increases the electric field strength, thereby linearly increasing the deformation.

[0066] Specifically, the spring strain correction unit determines that the interface contact pressure of the active outer conductor 3 and the active inner conductor 4 with the test position is both unqualified based on the comparison result that the temperature abnormal range is greater than the first preset range.

[0067] Specifically, the spring strain correction unit determines that the interface contact pressure of the active outer conductor 3 with the test position is unqualified based on the comparison result that the temperature abnormal range is less than or equal to the first preset range and greater than the second preset range.

[0068] Specifically, the spring strain correction unit determines that the interface contact pressure of the active inner conductor 4 with the test position is unqualified based on the comparison result that the temperature abnormal range is less than or equal to the second preset range.

[0069] Specifically, the values of the first preset range and the second preset range are determined according to the diameters of the active outer conductor 3 and the active inner conductor 4 of the test probe 1. The value of the first preset range is the area of a circle with a diameter of 1.5 times the outer diameter of the active outer conductor 3, and the value of the second preset range is the area of a circle with a diameter of 2 times the diameter of the active inner conductor 4.

[0070] Specifically, the temperature abnormal range is determined according to the temperature distribution image. The temperature distribution image can be grayed, the corresponding temperature is determined according to the gray value, and the area where the pixel blocks greater than the temperature in the normal test process are connected is determined as the temperature abnormal range.

[0071] Specifically, the infrared acquisition assembly for acquiring the temperature distribution image of the PCB surface includes an infrared thermal imager, such as a MiX acoustic thermal imager, and the specific model and parameters are not limited.

[0072] Specifically, the unqualified contact pressure of the active inner conductor 4 with the test position will cause the contact resistance to increase significantly, and since the active inner conductor 4 is the main transmission path of the test signal, the Joule heat generated by the current passing through is mainly concentrated at the contact point between the probe tip and the test point; and the unqualified contact pressure of the active outer conductor 3 with the test position will also cause the contact resistance to increase significantly, resulting in multiple reflections of high-frequency signals at the interface, and the reflected signals will go back and forth between the active outer conductor 3 and the test point, and finally be converted into Joule heat, and at the same time, the resistance of the active outer conductor 3 itself will increase due to the poor contact, resulting in additional Joule heat generated by the shielding current passing through, and the temperature is mainly concentrated in the contact area between the active outer conductor 3 and the test point, surrounding the active inner conductor 4 area; and under the condition that the contact pressure of both the active outer conductor 3 and the active inner conductor 4 with the test position is unqualified, the heating situation will be more serious, and the heat diffusion will be more serious, resulting in a larger temperature abnormality range than the condition that the contact pressure of the active outer conductor 3 with the test position is unqualified.

[0073] Specifically, the spring strain correction unit sets a plurality of voltage correction coefficients based on the comparison result of the temperature difference and the preset difference value under the condition that the interface contact pressure is unqualified, so as to optimize the voltage adjustment coefficient based on the plurality of voltage correction coefficients.

[0074] Specifically, the spring strain correction unit determines to optimize the voltage adjustment coefficient with a first voltage correction coefficient based on the comparison result that the temperature difference is greater than a first preset difference value.

[0075] The spring strain correction unit determines to optimize the voltage adjustment coefficient with a second voltage correction coefficient based on the comparison result that the temperature difference is less than or equal to the first preset difference value and greater than a second preset difference value.

[0076] Specifically, the temperature difference is the difference between the highest temperature in the temperature abnormality range and a preset temperature, and the value of the preset temperature is the highest temperature in the test under the condition that the contact pressure is qualified, and the optional range is set to [30℃, 50℃], and the embodiment of the present application preferably 30℃.

[0077] Specifically, the value of the preset difference value is determined according to the historical test process, at least 300 test points whose contact pressure becomes qualified after voltage adjustment are selected, the temperature mode and the temperature average value of each test point are determined, the difference between the temperature mode and the preset temperature is determined as the first preset difference value, and the difference between the temperature average value and the preset temperature is determined as the second preset difference value, the optional range of the second preset difference value is set to [10℃, 30℃], and the embodiment of the present application preferably 15℃, and the optional range of the first preset difference value is set to [20℃, 50℃], and the embodiment of the present application preferably 35℃.

[0078] Specifically, for the active outer conductor 3, the value range of the first voltage correction coefficient is set to [1.18, 1.25], and the value range of the second voltage correction coefficient is set to [1.14, 1.17], and the embodiment of the application preferably 1.16; for the active inner conductor 4, the value range of the first voltage correction coefficient is set to [1.11, 1.15], and the value range of the second voltage correction coefficient is set to [1.03, 1.1], and the embodiment of the application preferably 1.05.

[0079] Specifically, the strain threshold adjustment unit determines whether to adjust the preset compression state representation value based on a comparison result that the optimization frequency is greater than a preset frequency.

[0080] The strain threshold adjustment unit determines not to adjust the preset compression state representation value based on a comparison result that the optimization frequency is less than or equal to the preset frequency.

[0081] It can be understood that the stiffness is an inherent property of the spring, which is determined by the elastic modulus of the material and the geometric parameters. When the spring is fatigued or aged due to multiple compressions, its stiffness will gradually decrease. If the compression amount remains unchanged, according to Hooke's law, the contact pressure will linearly decrease with the decrease of the stiffness. Therefore, when it is found that the control voltage of the piezoelectric ceramic sheet needs to be corrected at a relatively large frequency, it is necessary to adjust the preset compression state representation value to improve the judgment criterion of whether the interface contact quality is qualified.

[0082] Specifically, the optimization frequency is the percentage of the number of test probes that are optimized to the total number of test probes.

[0083] Specifically, the preset frequency is determined according to historical test processes. The test data of at least 30 test batches is taken to determine the average value and the standard deviation of the optimization frequency under normal test conditions. The preset frequency is the sum of the average value and 3 times the standard deviation, and the optional range is set to [15%, 30%], and the embodiment of the application is preferably 20%.

[0084] Specifically, the strain threshold adjustment unit sets a plurality of threshold adjustment coefficients based on the frequency difference between the optimization frequency and the preset frequency, so as to increase the preset compression state representation value according to the plurality of threshold adjustment coefficients.

[0085] Specifically, the strain threshold adjustment unit determines to increase the preset compression state representation value by a first threshold adjustment coefficient based on a comparison result that the frequency difference is greater than a preset frequency difference;

[0086] The strain threshold adjustment unit determines to increase the preset compression state representation value by a second threshold adjustment coefficient based on a comparison result that the frequency difference is less than or equal to the preset frequency difference.

[0087] Specifically, the preset frequency difference value is set to [3%, 8%], and the embodiment of the application is preferably 5%; for the active outer conductor 3: the value range of the first threshold adjustment coefficient is set to [1.17, 1.23], and the embodiment of the application is preferably 1.21, and the value range of the second threshold adjustment coefficient is set to [1.1, 1.16], and the embodiment of the application is preferably 1.12; for the active inner conductor 4: the value range of the first threshold adjustment coefficient is set to [1.12, 1.19], and the embodiment of the application is preferably 1.18, and the value range of the second threshold adjustment coefficient is set to [1.07, 1.11], and the embodiment of the application is preferably 1.09.

[0088] So far, the technical solutions of the application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the application, and the technical solutions after the changes or replacements will all fall within the protection scope of the application.

Claims

1. A probe connector device for PCB board connection testing, characterized by, The application comprises: a data acquisition module comprising an infrared acquisition component for acquiring a temperature distribution image of a PCB board surface, and a strain sensor for acquiring spring deformation; a test control module comprising, an interface contact quality determination unit for determining a resistance variation coefficient based on a plurality of contact resistances between a test probe and a test position, and determining whether the interface contact quality between the test probe and the test position is qualified according to the resistance variation coefficient; a spring strain determination unit for determining a compression state characteristic value of an outer conductor spring or an inner conductor spring based on a strain value of the strain sensor under the condition that the interface contact quality is determined to be unqualified, and setting a plurality of voltage adjustment coefficients to adjust a control voltage of a piezoelectric ceramic sheet according to a comparison result of the compression state characteristic value and a preset compression state characteristic value; a spring strain correction unit for determining a temperature abnormal range based on the temperature distribution image, determining that an interface contact pressure between a movable outer conductor or a movable inner conductor and the test position is unqualified based on the temperature abnormal range, and setting a plurality of voltage correction coefficients to optimize the voltage adjustment coefficients according to a temperature difference between a highest temperature in the temperature abnormal range and a preset temperature; a strain threshold adjustment unit for adjusting the preset compression state characteristic value based on an optimization frequency of the voltage correction coefficients.

2. The probe connector device for PCB board connection testing of claim 1, wherein, The probe connector device further comprises: a test probe comprising a movable outer conductor arranged to shield a signal, an outer conductor spring for stretching and contracting the movable outer conductor, a first piezoelectric ceramic sheet coaxially installed with the outer conductor spring, a movable inner conductor coaxially installed with the movable outer conductor for establishing electrical connection, an inner conductor spring for stretching and contracting the movable inner conductor, and a second piezoelectric ceramic sheet coaxially installed with the inner conductor spring, wherein a steel wire inner part of the outer conductor spring and the inner conductor spring is embedded with a strain sensor, respectively; a probe connection mechanism comprising a first probe connection mechanism and a second probe connection mechanism, the first probe connection mechanism comprises a plurality of first single channels for placing a plurality of the test probes, a first pressing plate for fixing the plurality of first single channels, a first main support embedded with the first pressing plate for providing rigid support, and a positioning column arranged at the bottom of the first main support for aligning a PCB board and a probe connector; the second probe connection mechanism comprises a plurality of second single channels for placing a plurality of the test probes, a second pressing plate for fixing the plurality of second single channels, a second main support embedded with the second pressing plate for providing rigid support, and a connecting bolt arranged at the bottom of the second main support for fixing the PCB board and the probe connector.

3. The probe connector device for PCB board connection testing of claim 1, wherein, The interface contact quality determination unit determines that the interface contact quality is unqualified based on a comparison result that the resistance variation coefficient is greater than a preset resistance variation coefficient; The interface contact quality determination unit determines that the interface contact quality is qualified based on a comparison result that the resistance variation coefficient is less than or equal to the preset resistance variation coefficient.

4. The probe connector device for PCB board connection testing of claim 3, wherein, The spring strain determination unit sets a plurality of voltage adjustment coefficients based on a comparison result of the compression state representation value and a preset representation value under a condition that the interface contact quality is determined to be unqualified, so as to increase the control voltage of the piezoelectric ceramic sheet based on the plurality of voltage adjustment coefficients.

5. The probe connector device for PCB board connection testing of claim 4, wherein, The spring strain correction unit determines that the interface contact pressure of the movable outer conductor and the movable inner conductor with the test position is both unqualified based on a comparison result that the temperature abnormal range is greater than a first preset range.

6. The probe connector device for PCB board connection testing of claim 4, wherein, The spring strain correction unit determines that the interface contact pressure of the movable outer conductor with the test position is unqualified based on a comparison result that the temperature abnormal range is less than or equal to the first preset range and greater than a second preset range.

7. The probe connector device for PCB board connection testing of claim 4, wherein, The spring strain correction unit determines that the interface contact pressure of the movable inner conductor with the test position is unqualified based on a comparison result that the temperature abnormal range is less than or equal to the second preset range.

8. The probe connector device for PCB board connection testing according to claim 5 or 6 or 7, characterized in that, The spring strain correction unit sets a plurality of voltage correction coefficients based on a comparison result of the temperature difference and a preset difference value under a condition that the interface contact pressure is determined to be unqualified, so as to optimize the voltage adjustment coefficient based on the plurality of voltage correction coefficients.

9. The probe connector device for PCB board connection testing of claim 1, wherein, The strain threshold adjustment unit determines to adjust the preset compression state representation value based on a comparison result that the optimization frequency is greater than a preset frequency.

10. The probe connector device for PCB board connection testing of claim 9, wherein, The spring strain correction unit sets a plurality of threshold adjustment coefficients based on a frequency difference value of the optimization frequency and the preset frequency, so as to increase the preset compression state representation value according to the plurality of threshold adjustment coefficients.

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