Spacing-adjustable probe connector device

Abstract

The invention relates to the technical field of integrated circuit testing, in particular to a distance-adjustable probe connector device which comprises an impedance detection unit which comprises a connector fixing part, a connector rotating part, a single connection port, a signal probe and a grounding probe. The impedance data unit is used for determining a characteristic impedance value of the tested microstrip line based on data acquired by the signal probe and the grounding probe; the pressure detection unit is used for determining the contact pressure according to the telescopic displacement of the signal probe and the grounding probe; the control unit determines the allowable range of the contact pressure of the probes based on the line width of the microstrip line to be tested and the distance between the probes, and adjusts the angle between the grounding probe and the surface of the PCB based on the contact pressure difference between the signal probe and the grounding probe and the line width of the microstrip line. And adjusting the contact pressure of the signal probe to obtain the effective characteristic impedance value of the tested microstrip line. According to the invention, the angle and pressure of the grounding probe are intelligently adjusted, and the problem of impedance measurement drift caused by pressure imbalance of double probes is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit testing, and in particular to a probe connector device with adjustable spacing. Background Art

[0002] In the field of high-speed circuit design and manufacturing, accurate measurement of characteristic impedance is a core link in ensuring signal integrity. Traditional methods rely on impedance strips (test coupons) as the basis for evaluation, simulating actual trace characteristics by designing independent test structures. However, there are significant differences between impedance strips and actual traces within PCB boards: First, impedance strips are usually located in non-functional areas at the edge of the board, and their trace spacing, line width, and dielectric environment cannot replicate the complex stacking structure within high-density multi-layer boards; second, due to the influence of etching uniformity, fluctuations in material dielectric constants, and interlayer pressing tolerances, impedance strips cannot reflect the actual impedance distribution within the board; third, as electronic devices develop towards miniaturization and high frequency, applications such as 5G communications and AI chips have impedance control accuracy requirements of ±3% or even ±1%. However, the deviation introduced by impedance strips due to factors such as position offset and reference layer discontinuity can be as high as ±10%, far exceeding the current process tolerance range. Although time domain reflectometry (TDR) can directly locate impedance mutation points by transmitting step pulses and analyzing the reflected waveform, its commercial probes are mostly fixed-spacing structures, which are difficult to adapt to the diversity of pad spacing at the end of differential traces. In addition, existing technologies do not address the potential interference of probe contact pressure on measurement accuracy.

[0003] Current TDR measurements face two key bottlenecks: First, the spacing between the differential trace end connection points (such as BGA pads and gold fingers) varies dynamically with package type, making fixed probes incapable of fully compatible detection. Second, uneven probe contact pressure introduces additional impedance perturbations. Insufficient pressure increases contact resistance, while excessive pressure causes microstrip line deformation. Furthermore, the pressure difference between the signal and ground pins disrupts the symmetry of the measurement loop, causing ringing distortion in the reflected signal. These two issues are particularly prominent when measuring high-precision impedance boards: spacing mismatch creates detection blind spots, and pressure fluctuations cause impedance readings to drift by more than ±5%, hindering yield control and performance verification of high-speed PCBs.

[0004] Chinese Patent Publication No.: CN105938160A discloses an impedance testing device, comprising: a switching mounting mechanism; at least three probes, each of which is a grounding probe or a signal probe, and is mounted on the switching mounting mechanism. Some or all of the probes are driven by the switching mounting mechanism to switch between a test position and a non-test position. The switching mounting mechanism drives two selected probes to the test position each time in a combination of one signal probe and another signal probe or in a combination of one signal probe and one grounding probe, and the remaining non-selected probes are switched to the non-test position. The above-mentioned impedance testing device can ensure that when using two selected probes for impedance testing, the non-selected probes are kept away from the circuit board under test, thereby avoiding contact with other parts of the circuit board under test, without interfering with the test, ensuring the accuracy of the test results, and preventing short circuits that may damage the measuring instrument. It can be seen that the impedance testing device has the following problems: the impedance testing device switches the probes between the test and non-test positions by switching the mounting mechanism, effectively avoiding accidental contact between the non-test probes and the circuit board under test, thereby preventing short circuits and signal interference. However, the device fails to address the impact of uneven contact pressure between the signal probe and the ground probe on measurement accuracy. This problem arises from the fact that during actual testing, due to factors such as the contact state of the probes with the circuit board surface, the probes' own stiffness, or installation deviations, the pressure applied by the signal probe and the ground probe is inconsistent. This pressure difference causes changes in contact resistance, which in turn affects the transmission characteristics of high-frequency signals, causing drift and distortion in the impedance measurement results, which is particularly significant in precision impedance testing. Summary of the Invention

[0005] To this end, the present invention provides a probe connector device with adjustable spacing to overcome the problem in the prior art that uneven probe contact pressure affects measurement accuracy.

[0006] To achieve the above object, the present invention provides a probe connector device with adjustable spacing, comprising: An impedance detection unit comprising a connector fixed portion, a connector rotating portion connected to the connector fixed portion via a rotating shaft assembly, a single connection port disposed at one end of the connector fixed portion, a signal probe disposed on the connector fixed portion via a first spring assembly, and a ground probe disposed on the connector rotating portion via a second spring assembly, wherein the connector rotating portion is rotated by the rotating shaft assembly to adjust the spacing between the signal probe and the ground probe; an impedance data unit connected to the impedance detection unit via the single connection port, for determining a characteristic impedance value of the tested microstrip line based on data acquired by the signal probe and the ground probe; a displacement unit connected to the impedance detection unit, configured to control the impedance detection unit to move to a target position of the microstrip line to be tested, and to adjust the contact pressure between the signal probe and the ground probe and the microstrip line by controlling the height of the impedance detection unit to perform impedance detection; a pressure detection unit connected to the impedance detection unit, for determining a contact pressure of the signal probe according to the spring expansion and contraction displacement of the signal probe, and determining a contact pressure of the ground probe according to the spring expansion and contraction displacement of the ground probe; A control unit is connected to the impedance detection unit, the impedance data unit, the pressure detection unit, and the displacement unit, respectively, and is used to determine an allowable range of contact pressure of the probe based on the line width of the microstrip line to be tested and the probe spacing, adjust the angle between the ground probe and the PCB board surface to reduce the contact pressure difference based on the contact pressure difference between the signal probe and the ground probe and the line width of the microstrip line, and adjust the contact pressure of the signal probe to obtain an effective characteristic impedance value of the microstrip line to be tested.

[0007] Furthermore, the control unit obtains a first contact pressure difference between the signal probe contact pressure and the ground probe contact pressure and a line width of the tested microstrip line based on the first state, and determines an angle adjustment amount of the ground probe; The first state is that the displacement unit performs impedance detection using a height value corresponding to a middle value of an allowable range of contact pressure of the probe.

[0008] Further, the control unit obtains a second contact pressure difference between the signal probe contact pressure and the ground probe contact pressure based on the second state; The second state is that the control unit uses the ground probe with an adjusted angle to perform impedance detection.

[0009] Furthermore, the angle adjustment amount of the grounding probe is positively correlated with the line width, and the angle adjustment amount of the grounding probe is positively correlated with the first contact pressure difference.

[0010] Furthermore, the control unit obtains a drift trend of the impedance detection result based on the second state, and adjusts the signal probe contact pressure and the ground probe contact pressure according to the drift trend and the second contact pressure difference, so as to obtain the characteristic impedance value of the tested microstrip line after adjustment through the impedance data unit.

[0011] Furthermore, the control unit determines the drift trend based on a plurality of signal probe contact pressures acquired in the second state and a plurality of impedance detection results detected under the corresponding contact pressures.

[0012] Furthermore, the control unit determines the step length between the contact pressures of each signal probe in the second state based on the allowable range of contact pressure, and determines the number of steps of the contact pressure of each signal probe in the second state based on the allowable range of contact pressure and the second contact pressure difference, wherein the number of steps is positively correlated with the second contact pressure difference.

[0013] Furthermore, the control unit obtains the effective characteristic impedance value of the tested microstrip line based on the third state; The third state is to perform impedance detection after adjusting the contact pressure of the signal probe according to the drift trend and the second contact pressure difference.

[0014] Furthermore, the adjustment direction of the contact pressure of the signal probe is determined according to the drift trend; The adjustment amount of the signal probe contact pressure is positively correlated with the second contact pressure difference.

[0015] Furthermore, the control unit records the contact pressure of the signal probe in the third state after adjustment, and corrects the permissible range of the contact pressure according to the current line width and the probe spacing.

[0016] Compared with the prior art, the beneficial effect of the present invention is that it significantly improves the accuracy and adaptability of high-speed PCB microstrip line characteristic impedance measurement through an innovative adjustable spacing probe structure and intelligent pressure collaborative control mechanism. The spacing between the signal probe and the ground probe is dynamically adjusted by the rotating shaft assembly, solving the industry pain point that traditional fixed probes are not compatible with diverse pad spacings. At the same time, based on real-time detection and feedback control of contact pressure, the ground probe angle and signal probe pressure are intelligently adjusted, completely eliminating the impedance measurement drift problem caused by the imbalance of the dual probe pressure. This design has a breakthrough in the deep integration of mechanical adjustment, pressure sensing and algorithm control, which not only achieves high-precision impedance measurement of ±1%, but also greatly expands the applicability of probe connectors in high-density PCB scenarios such as 5G communications and AI chips, providing reliable protection for high-speed circuit signal integrity verification.

[0017] Furthermore, the present invention effectively suppresses the interference of contact pressure difference on measurement results through the angle adaptive adjustment mechanism driven by the rotating shaft. Based on the dynamic analysis of the microstrip line width and the initial pressure difference, the rotation angle of the grounding probe is accurately controlled to make the contact pressure of the two probes tend to be balanced, avoiding microstrip line deformation or abnormal contact resistance due to uneven pressure distribution, and ensuring the stability of the impedance measurement loop from the root.

[0018] Furthermore, the present invention significantly improves the reliability of characteristic impedance values ​​through drift trend analysis and pressure collaborative optimization strategy, collects impedance data at multiple pressure points after angle adjustment, fits the pressure-impedance drift law through an algorithm, and intelligently corrects the signal probe contact pressure in combination with the residual pressure difference, so that the measurement point is accurately positioned in the impedance stability range, completely eliminating systematic measurement errors.

[0019] Furthermore, the present invention achieves continuous optimization of long-term measurement consistency through a self-correction mechanism of the allowable range of contact pressure, feeds back the measured optimized pressure value to the line width-spacing-pressure mapping model, and dynamically corrects the boundary of the allowable pressure range, so that the device can adapt to dynamic factors such as material aging and environmental changes, thereby ensuring the measurement accuracy of the equipment throughout its life cycle.

[0020] Furthermore, the present invention combines high compatibility with ease of operation through an integrated elastic probe structure and displacement control unit. The spring component gives the probe the ability to adapt to the surface of the microstrip line, and the displacement unit accurately controls the overall height and plane angle, allowing the device to quickly adapt to PCB boards of different thicknesses and curved traces, greatly improving the detection efficiency of complex scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the probe connector device with adjustable spacing of the present invention; Figure 2 A schematic diagram of spacing adjustment of the probe connector device with adjustable spacing according to the present invention; Figure 3 An enlarged view of part A of the probe connector device with adjustable spacing according to the present invention; Figure 4 A connection block diagram of the probe connector device with adjustable spacing according to the present invention; In the figure, 11-connector fixing part; 12-signal probe; 13-first spring assembly; 21-connector rotating part; 22-ground probe; 23-second spring assembly; 3-rotating shaft assembly; 4-single connection port; 5-microstrip line. DETAILED DESCRIPTION

[0022] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0023] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0025] See also Figure 4 As shown, it is a connection block diagram of a probe connector device with adjustable spacing of the present invention. The present invention provides a probe connector device with adjustable spacing, comprising: An impedance detection unit comprising a connector fixed portion, a connector rotating portion connected to the connector fixed portion via a rotating shaft assembly, a single connection port disposed at one end of the connector fixed portion, a signal probe disposed on the connector fixed portion via a first spring assembly, and a ground probe disposed on the connector rotating portion via a second spring assembly, wherein the connector rotating portion is rotated by the rotating shaft assembly to adjust the spacing between the signal probe and the ground probe; an impedance data unit connected to the impedance detection unit via the single connection port, for determining a characteristic impedance value of the tested microstrip line based on data acquired by the signal probe and the ground probe; a displacement unit connected to the impedance detection unit, configured to control the impedance detection unit to move to a target position of the microstrip line to be tested, and to adjust the contact pressure between the signal probe and the ground probe and the microstrip line by controlling the height of the impedance detection unit to perform impedance detection; In a specific embodiment, the displacement unit uses a precision ball screw module to drive XY plane movement (positioning the target microstrip line). The module is powered by a stepper motor and achieves closed-loop position feedback control through a high-resolution encoder (such as an optical encoder or a magnetic encoder). The module is mounted on a stable base and carries the impedance detection unit to perform two-dimensional plane movement above the PCB board surface. The positioning accuracy should reach the micron level to meet the requirements of precise positioning of the microstrip line pad.

[0026] In a specific embodiment, the displacement unit uses a precision ball screw module to drive the Z-axis movement (to adjust the contact pressure). This module is responsible for controlling the vertical height of the entire impedance detection unit (or probe portion) relative to the PCB board surface. By precisely controlling the downward pressure depth of the Z-axis, the compression of the signal probe and the ground probe can be indirectly controlled, thereby adjusting their contact pressure. The Z-axis is also equipped with a high-resolution encoder for closed-loop position control to ensure the accuracy and repeatability of height (i.e., pressure) adjustment. Force / position hybrid control is a common strategy: first quickly move to the approach position, and then switch to a precise force control mode based on pressure feedback to make final contact.

[0027] In one specific embodiment, the displacement unit integrates a high-precision rotation stage or a direct-drive rotary motor (θ-axis rotation) between the impedance detection unit's mounting base and the XYZ motion platform. This rotational axis (θ-axis) drives the entire impedance detection unit around its vertical axis (Z-axis), ensuring that the mid-perpendicular line connecting the signal probe and the ground probe is precisely perpendicular to the PCB surface. The rotation stage is typically driven by a micro servo motor or stepper motor, using a harmonic reducer or planetary reducer to increase torque and improve resolution. It is also equipped with a high-precision angle encoder (such as a photoelectric encoder) for closed-loop angle control.

[0028] a pressure detection unit connected to the impedance detection unit, for determining a contact pressure of the signal probe according to the spring expansion and contraction displacement of the signal probe, and determining a contact pressure of the ground probe according to the spring expansion and contraction displacement of the ground probe; In one specific embodiment, the pressure detection unit can be implemented using a strain gauge force sensor. A miniature resistance strain gauge (e.g., a full-bridge or half-bridge strain gauge in a Wheatstone bridge configuration) is precisely attached to the internal support shaft or external load-bearing housing of the first spring assembly (corresponding to the signal probe) and the second spring assembly (corresponding to the ground probe). When the probe is compressed, causing the spring assembly to undergo a slight deformation, the resistance value of the strain gauge changes accordingly. By measuring the unbalanced voltage signal output by the bridge, the axial force applied to the probe (i.e., contact pressure) can be calculated. This solution is technically mature, moderately cost-effective, and highly accurate (up to ±0.5% FS or higher), and is widely used in the field of industrial force measurement.

[0029] In a specific embodiment, the pressure detection unit can also be realized by converting displacement into pressure through the magnetostrictive effect. A small permanent magnet linked to the probe axis is provided inside or near the first spring assembly and the second spring assembly. A linear Hall effect sensor is installed at a corresponding position fixed to the fixed part / rotating part of the connector. The pressure on the probe causes the spring to compress, which drives the permanent magnet to move relative to the Hall sensor and changes the magnetic field strength around it. The linear voltage signal output by the Hall sensor is proportional to the displacement of the permanent magnet (i.e., the amount of spring compression). The contact pressure can be accurately calculated based on the pre-calibrated spring stiffness coefficient. This solution is non-contact, frictionless, long-lasting, and has good anti-interference performance. It is a common means of precision displacement / pressure detection.

[0030] The pressure detection unit includes necessary signal conditioning circuits (such as amplification, filtering, and temperature compensation circuits) and analog-to-digital converters (ADCs) to convert the analog signals (voltage, charge) output by the sensing element into high-precision digital signals.

[0031] The pressure detection unit is connected to the control unit via a standard digital communication interface or an analog voltage output interface, and transmits the measured values ​​of the signal probe contact pressure and the ground probe contact pressure in real time.

[0032] A control unit is connected to the impedance detection unit, the impedance data unit, the pressure detection unit, and the displacement unit, respectively, and is used to determine an allowable range of contact pressure of the probe based on the line width of the microstrip line to be tested and the probe spacing, adjust the angle between the ground probe and the PCB board surface to reduce the contact pressure difference based on the contact pressure difference between the signal probe and the ground probe and the line width of the microstrip line, and adjust the contact pressure of the signal probe to obtain an effective characteristic impedance value of the microstrip line to be tested.

[0033] See also Figures 1 to 3 As shown, they are respectively a structural schematic diagram of the probe connector device with adjustable spacing of the present invention, a schematic diagram of spacing adjustment of the probe connector device with adjustable spacing of the present invention, and an enlarged view of part A of the probe connector device with adjustable spacing of the present invention; In a specific embodiment, the control unit controls the shaft assembly 3 to rotate the connector rotating part 21 so that the end distance between the signal probe 12 and the ground probe 22 meets the spacing of the microstrip line to be tested; then, the control unit controls the displacement unit to rotate the impedance detection unit until the midline of the connecting line between the ends of the signal probe 12 and the ground probe 22 is perpendicular to the PCB board.

[0034] It can be understood that the control unit controls the displacement unit to rotate the impedance detection unit until the midline of the line connecting the ends of the signal probe 12 and the ground probe 22 is perpendicular to the PCB board, so as to keep the lowering height of the two probes initially consistent when performing impedance detection, thereby reducing the contact pressure difference between the signal probe 12 and the ground probe 22.

[0035] The control unit determines the allowable range of contact pressure of the signal probe [P] based on the line width W of the microstrip line to be tested and the distance D between the signal probe 12 and the ground probe 22 through a preset line width-distance-pressure mapping relationship. min ,P max ], wherein the mapping relationship satisfies: , , Wherein, W is the line width of the microstrip line to be tested, in millimeters (mm); D is the distance between the signal probe 12 and the ground probe 22, in millimeters (mm); k1 is the lower limit proportional coefficient, in Newtons (N), with a value range of 8N to 12N. Preferably, k1 is 10N; k2 is the upper limit proportional coefficient, in Newtons (N), with a value range of 15N to 25N. Preferably, k2 is 20N; b is the pressure offset, in Newtons (N), with a value range of 2N to 5N. Preferably, b is 2N.

[0036] It can be understood that the line width W of the microstrip line to be tested and the spacing D between the signal probe 12 and the ground probe 22 can be specific data directly input through an input device, or obtained by detecting the microstrip line to be tested on the PCB board through other detection equipment. The method in which the control unit obtains the line width data and the spacing data is not limited here.

[0037] It can be understood that the ratio of line width and probe spacing directly determines the mechanical stability and electric field distribution characteristics of the microstrip line: when the line width is small, the cross-sectional area of ​​the microstrip line decreases, resulting in a decrease in compressive strength, and the maximum pressure needs to be reduced to avoid plastic deformation; when the probe spacing is small, the electric field coupling between the two probes is enhanced, and excessive contact pressure will expand the contact area between the probe and the copper foil, change the local capacitance distribution, and thus interfere with the integrity of the high-frequency signal. The offset is used to compensate for the inherent stiffness of the probe structure and the minimum contact pressure between the probe and the microstrip line; among them, the upper and lower limit proportional coefficients are calibrated by the Young's modulus of the copper foil and the dielectric layer compressive strength experiment, and the offset is calibrated by the effective pressure experiment of the probe, which will not be repeated here.

[0038] The present invention provides a dynamic constraint boundary for contact pressure by establishing a quantitative mapping relationship between line width, spacing and pressure, avoiding microstrip line deformation or contact resistance abnormality caused by pressure mismatch, ensuring the reliability of impedance measurement from the source, and providing a contact pressure benchmark for the device in subsequent characteristic impedance measurements.

[0039] Specifically, the control unit obtains a first contact pressure difference between the signal probe contact pressure and the ground probe contact pressure and a line width of the tested microstrip line based on the first state, and determines an angle adjustment amount of the ground probe 22; The first state is that the displacement unit performs impedance detection using a height value corresponding to a middle value of an allowable range of contact pressure of the probe.

[0040] Specifically, the angle adjustment amount of the ground probe 22 is positively correlated with the line width, and the angle adjustment amount of the ground probe 22 is positively correlated with the first contact pressure difference.

[0041] In a specific embodiment, the control unit controls the displacement unit to move to the target position of the microstrip line to be tested, and adjusts the distance between the signal probe 12 and the PCB board surface to control its contact pressure. The impedance detection is performed using the height value of the signal probe 12 corresponding to the middle value of the contact pressure allowable range. This is the first state, wherein the middle value is 1 / 2×(P min +P max ).

[0042] It can be understood that by performing impedance detection using the height value corresponding to the middle value of the contact pressure allowable range of the signal probe 12, both probes can be placed within the contact pressure allowable range at the same time, and sufficient adjustment space can be provided for the subsequent pressure adjustment of the ground probe 22 and the signal probe 12.

[0043] Based on the first state, the pressure detection unit obtains the contact pressure of the signal probe and the contact pressure of the ground probe in real time, and calculates a first pressure difference. The calculation formula of the first contact pressure difference is specifically: , Among them, △P1 is the first contact pressure difference, the unit is Newton (N); P s is the contact pressure of the signal probe, in Newton (N); P g is the ground probe contact pressure, in Newton (N).

[0044] It is understandable that impedance testing within the allowable range of contact pressure can initially suppress the risk of single-needle overload, but the pressure difference between the two probes will still destroy the impedance balance of the measurement loop: the probe on the side with higher pressure will increase the parallel capacitance due to the increase in contact area, while the series impedance on the side with lower pressure will increase due to the increase in contact resistance. The superposition of the two will cause ringing distortion in the reflected signal; the quantitative extraction of the first pressure difference provides the key input for subsequent angle compensation, and improves the TDR waveform signal-to-noise ratio by eliminating the asymmetric contact impedance.

[0045] In a specific embodiment, the control unit adjusts the angle between the ground probe 22 and the PCB surface to reduce the pressure difference according to the first contact pressure difference ΔP1 and the line width W of the microstrip line, and the angle adjustment amount Δθ satisfies: , Among them, △θ is the angle adjustment amount, the unit is degree (°), △θ≤1°; k3 is the pressure difference expansion coefficient, the unit is N -1 , the value range is 0.05N -1 ~0.1N -1 , preferably, k3 is 0.1N -1 ; k4 is the line width safety factor, the unit is ° / mm, the value range is 0.2° / mm~0.4° / mm, preferably, k4 is 0.3° / mm.

[0046] It can be understood that the pressure difference expansion coefficient k3 is used to expand the adjustment angle of the ground probe 22 according to the magnitude of the first contact pressure difference; the line width safety factor k4 is used to ensure that when the pressure difference is reduced by adjusting the angle of the ground probe 22, the ground probe 22 will not deviate from the microstrip line, and the wider the line width, the greater the adjustment angle; among them, the line width safety factor k4 is calibrated according to the mechanical model and geometric model of the ground probe 22, and the pressure difference expansion coefficient k3 is calibrated based on a number of historical experimental data, which will not be repeated here.

[0047] Furthermore, the angle adjustment direction of the grounding probe 22 is determined based on the positive or negative value of the first contact pressure difference. Specifically, when the first contact pressure difference is positive (i.e., the signal probe contact pressure is greater than the grounding probe contact pressure), the control unit controls the rotation direction of the shaft assembly 3 to make the connector rotating part 21 tend to be parallel to the connector fixed part 11; when the first contact pressure difference is negative (i.e., the signal probe contact pressure is less than the grounding probe contact pressure), the control unit controls the rotation direction of the shaft assembly 3 to make the connector rotating part 21 move away from the direction parallel to the connector fixed part 11.

[0048] The present invention realizes adjustable probe spacing through adaptive angle adjustment of the impedance detection unit without increasing hardware complexity, effectively suppresses contact pressure imbalance caused by uncontrollable factors such as PCB surface unevenness or probe assembly tolerance, and significantly improves impedance measurement repeatability.

[0049] Specifically, the control unit obtains a second contact pressure difference between the signal probe contact pressure and the ground probe contact pressure based on the second state; The second state is that the control unit uses the ground probe 22 with an adjusted angle to perform impedance detection.

[0050] In a specific embodiment, the control unit controls the shaft assembly 3 to rotate the connector rotating portion 21 according to the angle adjustment amount Δθ and the angle adjustment direction, thereby rotating the grounding probe 22 to a target angle. The calculation formula for the second contact pressure difference is specifically: , Among them, △P2 is the second contact pressure difference, the unit is Newton (N); P s ' is the contact pressure of the signal probe after angle adjustment, in Newton (N); P g ' is the contact pressure of the ground probe after angle adjustment, in Newton (N).

[0051] Specifically, the control unit obtains the drift trend of the impedance detection result based on the second state, and adjusts the signal probe contact pressure and the ground probe contact pressure according to the drift trend and the second contact pressure difference, so as to obtain the characteristic impedance value of the tested microstrip line after adjustment through the impedance data unit.

[0052] Specifically, the control unit determines the drift trend based on a plurality of signal probe contact pressures acquired in the second state and a plurality of impedance detection results detected under the corresponding contact pressures.

[0053] Specifically, the control unit determines the step length between the contact pressures of each signal probe in the second state based on the allowable range of contact pressure, and determines the number of steps of the contact pressure of each signal probe in the second state based on the allowable range of contact pressure and the second contact pressure difference, wherein the number of steps is positively correlated with the second contact pressure difference.

[0054] In a specific embodiment, in the second state, the control unit gradually adjusts the contact pressure of the signal probe 12 with a preset step size through the displacement unit, and records the characteristic impedance value output by the impedance data unit at each pressure point; based on the recorded contact pressures of several signal probes and their corresponding characteristic impedance values, a linear regression algorithm is used to fit the slope of the impedance value changing with pressure, and the slope is used as a quantitative indicator of the drift trend.

[0055] It is understandable that in the second state, the angle of the ground probe 22 has been adjusted, and the residual dual-needle pressure difference (second contact pressure difference) has been reduced. However, slight changes in the contact pressure of the signal probe will still cause a systematic offset in the impedance reading. By collecting impedance data at different pressure points and analyzing the overall trend of impedance changes with pressure (such as linear increase or decrease), random noise interference can be eliminated and the inherent laws of the pressure-impedance relationship can be accurately captured. This drift trend reflects the sensitivity of contact pressure to impedance measurement and provides a directional basis for subsequent pressure optimization.

[0056] In a specific embodiment, the control unit determines the upper limit value P of the contact pressure allowable range according to the upper limit value P of the contact pressure allowable range. max and the lower limit P min Calculate the pressure adjustment step ΔP step , satisfying ΔP step =(P max -P min ) / N, where N is the fixed segment number, ranging from 10 to 20; at the same time, the pressure adjustment step number n is calculated according to the second contact pressure difference ΔP2, satisfying n=f×ΔP2, where n is the pressure adjustment step number, the unit is step, n is a positive integer, and 3 steps ≤ n ≤ 10 steps; f is the proportional coefficient, ranging from 3 steps / N to 5 steps / N; finally, in the second state, the displacement unit is controlled to move at ΔP step The contact pressure of the signal probe 12 is adjusted n times continuously with a step size of n, and the impedance value is recorded after each adjustment.

[0057] It is understandable that the pressure adjustment step size needs to cover the allowable range and avoid inefficiency caused by excessive density, so the pressure interval is divided into a fixed number of segments; and the number of adjustment steps needs to adapt to the residual influence of the pressure difference. The larger the second contact pressure difference, the stronger the imbalance of the contact system, and more data points are required to accurately capture the drift law; the setting of the proportional coefficient f ensures that the sampling density is increased when the second contact pressure difference is large, thereby improving the fitting accuracy of the drift trend.

[0058] The present invention adjusts the sampling steps by dynamically matching the pressure difference, optimizes the detection efficiency while ensuring the accuracy of trend analysis, and achieves a balance between measurement accuracy and speed.

[0059] Specifically, the control unit obtains the effective characteristic impedance value of the tested microstrip line based on the third state; The third state is to perform impedance detection after adjusting the contact pressure of the signal probe according to the drift trend and the second contact pressure difference.

[0060] Specifically, the adjustment direction of the contact pressure of the signal probe is determined according to the drift trend; The adjustment amount of the signal probe contact pressure is positively correlated with the second contact pressure difference.

[0061] In a specific embodiment, the control unit calculates the optimized value of the signal probe contact pressure based on the drift trend and the second contact pressure difference, controls the displacement unit to adjust the signal probe 12 to the pressure value, and then starts impedance detection. At this time, the system is in the third state, and the characteristic impedance value output by the impedance data unit is the effective characteristic impedance value.

[0062] It can be understood that the drift trend reveals the regular direction of the impedance value changing with pressure (such as the impedance increases or decreases when the pressure increases), while the second contact pressure difference reflects the degree of residual imbalance of the dual-probe contact system; combining the two can determine the optimal pressure operating point: when the drift trend shows that the impedance increases with increasing pressure, the pressure needs to be reduced to make the reading return to the stable zone, and vice versa. At the same time, the larger the residual pressure difference, the stronger the asymmetry of the contact system, and a larger pressure compensation amount is required to offset its influence; this optimization strategy can simultaneously suppress pressure sensitivity error and contact asymmetry error, so that the measurement point is located in the flat area of ​​the impedance-pressure curve, at which time small pressure fluctuations have the least effect on the reading.

[0063] The present invention accurately locates the optimal working point of impedance measurement by integrating drift trend and pressure difference information, so that a stable and reliable effective characteristic impedance value can be obtained with a single adjustment.

[0064] In a specific embodiment, the control unit sets the adjustment direction of the signal probe contact pressure to be opposite to the sign of the drift trend (if the trend is positive, the pressure is reduced, and if it is negative, the pressure is increased); the adjustment amount is calculated according to the formula Δp=m×|ΔP2|, where m is the pressure compensation coefficient, and the value range is 0.4~0.8. Preferably, m is 0.6.

[0065] It can be understood that the reverse design of the adjustment direction ensures that the pressure moves to the stable section of the drift curve (such as near the zero point of the slope) to avoid entering the sensitive area; the adjustment amount is proportional to the residual pressure difference because a larger pressure difference means that there is a significant imbalance in the contact system, and a larger compensation amount is required to eliminate its offset effect on the impedance reading; the value of the pressure compensation coefficient k is based on the calibration of the contact mechanics model, and its physical essence is the compensation strength required for unit pressure difference. This coefficient prevents over-adjustment oscillation while ensuring the correction effect.

[0066] The present invention achieves precise one-step optimization of contact pressure by quantitatively correlating the residual pressure difference with the adjustment amplitude, significantly improving detection efficiency and reliability.

[0067] Specifically, the control unit records the contact pressure of the signal probe in the third state after adjustment, and corrects the permissible range of the contact pressure according to the current line width and the probe spacing.

[0068] In a specific embodiment, the control unit records the contact pressure of the signal probe corresponding to the effective characteristic impedance value obtained after adjustment in the third state, and adjusts the contact pressure allowable range [P min , P max ] is modified to optimize the pressure benchmark for subsequent impedance testing of microstrip lines with the same or similar line width and spacing combinations.

[0069] Specifically, first, the contact pressure value of the signal probe corresponding to the effective characteristic impedance value obtained after adjustment in the third state is marked as the optimized pressure value P t ; Calculate the contact pressure allowable range [P min , P max ]’s original center point P center , where P center =(P min +P max ) / 2; Calculate the optimized pressure value P t With the original center point P center The deviation between them is δ, that is, δ=P t -P center .

[0070] The preset ratio k of the deviation δ c As the correction amount η, that is, η=k c ×δ; wherein the preset ratio k c The value range is 30% to 50% (i.e. 0.3≤k c ≤0.5), preferably, k c Take 40%.

[0071] The upper limit value P of the contact pressure allowable range is max and the lower limit P min Synchronously translate the correction amount η to form a new contact pressure allowable range [P min ',P max '],in: P min '=P min +η, P max '=P max +η, The new contact pressure allowable range [P min ',P max '] is associated with the current line width W and the probe spacing D, and is stored in or updated in the preset line width-spacing-pressure mapping relationship database.

[0072] It can be understood that the optimized pressure value P t It is the best working point verified after angle adjustment and pressure optimization under actual working conditions (taking into account the specific PCB surface conditions, probe conditions, environmental factors, etc.), reflecting the most stable measurement state for the current specific line width W and spacing D combination. The core of the correction process is to respect the original allowable range [P min , Pmax ], and effectively absorb the empirical information obtained from this measured optimization; by calculating the original center point P center r and P t The deviation δ of c (30% to 50%) as the correction value η, achieving partial compensation rather than completely following the measured value. This strategy effectively suppresses model oscillation: if the correction is completely based on δ (i.e., k c =100%), a single abnormal measurement or short-term fluctuation may cause the pressure range to jump sharply; and k c The design of <50% ensures the gradualness and robustness of the correction, allowing the model to smoothly adapt to long-term changes. This adaptive correction mechanism can continuously track the impact of dynamic factors such as probe elastic attenuation (material aging) and changes in friction coefficient caused by changes in ambient temperature and humidity on the optimal contact pressure, so that the pressure allowable range always maintains the best match with the actual working conditions. The preset proportional coefficient k c The setting of k (30% to 50%) scientifically balances the model stability and adaptability requirements: a too small k c (<30%) may cause the correction to be too slow and unable to effectively absorb the optimization information; too large k c If the range is greater than 50%, it may introduce excessive noise and reduce the long-term reliability of the model. By storing the revised new range in the database, this mechanism ensures the continuous optimization of the measurement benchmark throughout the life cycle of the equipment.

[0073] The present invention establishes a self-correction mechanism for the allowable contact pressure range driven by measurement data feedback, enabling the equipment to have continuous evolution capabilities, significantly improving the consistency and reliability of long-term measurements, and effectively overcoming the problem of decreased measurement accuracy in the traditional fixed pressure range due to device aging or environmental drift.

[0074] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A probe connector device with adjustable spacing, characterized in that: include: An impedance detection unit comprising a connector fixed portion, a connector rotating portion connected to the connector fixed portion via a rotating shaft assembly, a single connection port disposed at one end of the connector fixed portion, a signal probe disposed on the connector fixed portion via a first spring assembly, and a ground probe disposed on the connector rotating portion via a second spring assembly, wherein the connector rotating portion is rotated by the rotating shaft assembly to adjust the spacing between the signal probe and the ground probe; an impedance data unit connected to the impedance detection unit via the single connection port, for determining a characteristic impedance value of the tested microstrip line based on data acquired by the signal probe and the ground probe; a displacement unit connected to the impedance detection unit, configured to control the impedance detection unit to move to a target position of the microstrip line to be tested, and to adjust the contact pressure between the signal probe and the ground probe and the microstrip line by controlling the height of the impedance detection unit to perform impedance detection; a pressure detection unit connected to the impedance detection unit, for determining a contact pressure of the signal probe according to the spring expansion and contraction displacement of the signal probe, and determining a contact pressure of the ground probe according to the spring expansion and contraction displacement of the ground probe; A control unit is connected to the impedance detection unit, the impedance data unit, the pressure detection unit, and the displacement unit, respectively, and is used to determine an allowable range of contact pressure of the probe based on the line width of the microstrip line to be tested and the probe spacing, adjust the angle between the ground probe and the PCB board surface to reduce the contact pressure difference based on the contact pressure difference between the signal probe and the ground probe and the line width of the microstrip line, and adjust the contact pressure of the signal probe to obtain an effective characteristic impedance value of the microstrip line to be tested.

2. The probe connector device with adjustable spacing according to claim 1, wherein: The control unit obtains a first contact pressure difference between the signal probe contact pressure and the ground probe contact pressure and a line width of the tested microstrip line based on the first state, and determines an angle adjustment amount of the ground probe; The first state is that the displacement unit performs impedance detection using a height value corresponding to a middle value of an allowable range of contact pressure of the probe.

3. The probe connector device with adjustable spacing according to claim 2, wherein: The control unit acquires a second contact pressure difference between the signal probe contact pressure and the ground probe contact pressure based on the second state; The second state is that the control unit uses the ground probe with an adjusted angle to perform impedance detection.

4. The probe connector device with adjustable spacing according to claim 3, characterized in that: The angle adjustment amount of the grounding probe is positively correlated with the line width, and the angle adjustment amount of the grounding probe is positively correlated with the first contact pressure difference.

5. The probe connector device with adjustable spacing according to claim 3, characterized in that: The control unit obtains a drift trend of the impedance detection result based on the second state, and adjusts the signal probe contact pressure and the ground probe contact pressure according to the drift trend and the second contact pressure difference, so as to obtain the characteristic impedance value of the tested microstrip line after adjustment through the impedance data unit.

6. The probe connector device with adjustable spacing according to claim 5, characterized in that: The control unit determines the drift trend based on a plurality of signal probe contact pressures acquired in the second state and a plurality of impedance detection results detected under the corresponding contact pressures.

7. The probe connector device with adjustable spacing according to claim 6, wherein: The control unit determines the step length between the contact pressures of each signal probe in the second state based on the allowable range of contact pressure, and determines the number of steps of the contact pressure of each signal probe in the second state based on the allowable range of contact pressure and the second contact pressure difference, wherein the number of steps is positively correlated with the second contact pressure difference.

8. The probe connector device with adjustable spacing according to claim 7, wherein: The control unit obtains the effective characteristic impedance value of the tested microstrip line based on the third state; The third state is to perform impedance detection after adjusting the contact pressure of the signal probe according to the drift trend and the second contact pressure difference.

9. The probe connector device with adjustable spacing according to claim 8, wherein: The adjustment direction of the contact pressure of the signal probe is determined according to the drift trend; The adjustment amount of the signal probe contact pressure is positively correlated with the second contact pressure difference.

10. The probe connector device with adjustable spacing according to claim 9, wherein: The control unit records the contact pressure of the signal probe in the third state after adjustment, and corrects the permissible range of the contact pressure according to the current line width and the probe spacing.

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