A DC test probe device and a DC test system

Abstract

This invention discloses a DC test probe device and a DC test system. The DC test probe device has a magnetic coil and a vertical resistor assembly arranged along the axial direction of the probe body, and a probe outer shell layer arranged radially. A high-precision transmission mechanism is connected to the outside of the magnetic coil, and the inductance is dynamically adjusted by driving the coil to open and close. Inside the probe outer shell layer, a probe shielding layer and a probe conductive layer are integrated from the outside to the inside. The vertical resistor assembly is located between the probe conductive layer and the magnetic coil, and the probe impedance is adjusted by the patch pressing force. This device achieves integrated and precise control of inductance and impedance, reduces parasitic interference, and is suitable for DC parameter testing needs in various scenarios such as semiconductor chips and circuit boards.

Description

Technical Field

[0001] This invention relates to the field of electronic testing, and more specifically, to a DC test probe device and a DC test system. Background Technology

[0002] In the field of DC test technology, the inductance and impedance of the probe directly determine the stability and accuracy of the test signal. Traditional DC test probes have significant drawbacks: First, inductance adjustment is limited, and fixed inductor designs cannot adapt to a wide range of test scenarios; parasitic inductance can easily cause signal distortion during high-frequency testing. Second, impedance matching is insufficient; traditional series / parallel resistor adjustment methods introduce additional parasitic capacitance and inductance, interfering with the impedance characteristics of the device under test (DUT). Third, the structure is complex and redundant, relying on external circuits to adjust the inductance and impedance, resulting in increased system size and cost. Summary of the Invention

[0003] The purpose of this invention is to provide a DC test probe device and a DC test system.

[0004] In a first aspect, embodiments of the present invention provide a DC test probe device, comprising:

[0005] Magnetic suction coil and vertical resistor assembly arranged along the axial direction of the probe body;

[0006] A probe outer shell layer that wraps around the probe body radially.

[0007] A high-precision transmission mechanism is connected to the outside of the magnetic coil to drive the magnetic coil to perform opening and closing actions to adjust the probe inductance.

[0008] The probe outer shell layer has a probe shielding layer and a probe conductive layer integrated from the outside to the inside. The probe shielding layer is used to shield external electromagnetic interference, and the probe conductive layer is used to transmit test signals.

[0009] The vertical resistor assembly is located between the probe conductive layer and the magnetic coil, and is used to adjust the probe impedance by the patch pressing force.

[0010] In one possible implementation, the vertical resistance assembly comprises, from bottom to top, the following components along the axial direction of the probe body:

[0011] An elastic support layer serves as the bottom support structure for the vertical resistor assembly;

[0012] A nickel-chromium thin-film resistor is disposed above the elastic support layer and has a vertical structure with its axis perpendicular to the signal transmission direction of the probe conductive layer, serving as a basis for impedance adjustment.

[0013] A conductive via is disposed above the nickel-chromium thin-film resistor to connect the nickel-chromium thin-film resistor to the silicon nitride ceramic substrate;

[0014] A silicon nitrogen ceramic substrate is disposed above the conductive via, serving as the substrate for the chip bonding mechanism;

[0015] A gold plating layer is respectively disposed on the surface of the silicon nitrogen ceramic substrate facing the conductive via and on the contact surface of the nickel-chromium thin film resistor facing the silicon nitrogen ceramic substrate, for the purpose of reducing contact resistance.

[0016] In one possible implementation, the silicon nitrogen ceramic substrate is directly connected to the probe conductive layer via a press-fit process;

[0017] The contact area between the silicon nitrogen ceramic substrate and the nickel-chromium thin film resistor varies with the patch pressing force to adjust the impedance value of the nickel-chromium thin film resistor.

[0018] In one possible implementation, the magnetic coil is made of a high permeability material;

[0019] The high-precision transmission mechanism is connected to the outside of the magnetic coil;

[0020] The opening and closing distance of the magnetic coil has a linear or nonlinear mapping relationship with the inductance, and the high-precision transmission mechanism is any one of a mechanical spring, an electromagnet, or a piezoelectric ceramic actuator.

[0021] In one possible implementation, the probe outer shell layer is made of silver-plated copper and wraps around the probe shielding layer radially.

[0022] The probe shielding layer and the probe outer shell layer are filled with a microwave absorbing material, which works in conjunction with the probe shielding layer to enhance the shielding effect against external electromagnetic interference.

[0023] The probe conductive layer is located radially from the probe inside the probe shielding layer.

[0024] In one possible implementation, the probe conductive layer employs a four-wire Kelvin connection to separate the excitation end and the detection end within the probe conductive layer to eliminate the influence of contact resistance.

[0025] In one possible implementation, the elastic support layer is located below the nickel-chromium thin-film resistor and is made of an elastic material or a carbon-based elastic conductive material, used to support the nickel-chromium thin-film resistor and assist in current transmission.

[0026] In one possible implementation, the magnetic coil and the vertical resistor assembly are independently arranged along the probe axis, and both can be independently detached along the probe axis.

[0027] In one possible implementation, the nickel-chromium thin-film resistor located above the elastic support layer has a resistance value adjustable in the range of 1Ω-10kΩ and a parasitic capacitance of <0.1pF.

[0028] Secondly, embodiments of the present invention provide a DC testing system, comprising:

[0029] The test source module is used to output test signals as well as digital input and output control signals;

[0030] As described in any of the first aspects, the DC test probe device receives the test signal output by the test source module through a power supply harness and receives the digital input and output control signals through a control harness;

[0031] A probe station is used to carry the device under test, and the DC test probe device cooperates with the probe station to perform DC parameter testing on the device under test.

[0032] Compared to existing technologies, the advantages of this invention include: The DC test probe device and DC test system disclosed in this invention feature a magnetic coil and a vertical resistor assembly arranged axially along the probe body, and a probe outer shell layer arranged radially. A high-precision transmission mechanism is connected to the outside of the magnetic coil, dynamically adjusting the inductance by driving the coil's opening and closing action. The probe outer shell layer integrates a probe shielding layer and a probe conductive layer from the outside in. The vertical resistor assembly is located between the probe conductive layer and the magnetic coil, adjusting the probe impedance by applying a patch clamping force. This device achieves integrated and precise control of inductance and impedance, reduces parasitic interference, and is suitable for DC parameter testing needs in various scenarios such as semiconductor chips and circuit boards. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of the DC test probe device provided in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the architecture of a DC testing system provided in an embodiment of the present invention.

[0036] Reference numerals: 100-DC test probe device, 110-magnetic coil, 1101-high-precision transmission mechanism, 1201-elastic support layer, 1202-nickel-chromium thin film resistor, 1203-conductive via, 1204-silicon nitride ceramic substrate, 1205-gold plating layer, 130-probe shell layer, 1301-probe shielding layer, 1302-probe conductive layer. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] In order to solve the technical problems mentioned in the background art Figure 1 This is a schematic diagram of the structure of a DC test probe device provided in an embodiment of the present disclosure. The DC test probe device will be described in detail below. An embodiment of the present invention provides a DC test probe device 100, comprising:

[0040] A magnetic coil 110 and a vertical resistor assembly are arranged along the axial direction of the probe body.

[0041] A probe outer shell layer 130 is radially wrapped around the probe body.

[0042] A high-precision transmission mechanism 1101 is connected to the outside of the magnetic coil 110, which is used to drive the magnetic coil 110 to perform opening and closing actions to adjust the probe inductance.

[0043] The probe outer shell layer 130 has a probe shielding layer 1301 and a probe conductive layer 1302 integrated from the outside to the inside. The probe shielding layer 1301 is used to shield external electromagnetic interference, and the probe conductive layer 1302 is used to transmit test signals.

[0044] The vertical resistor assembly is located between the probe conductive layer 1302 and the magnetic coil 110, and is used to adjust the probe impedance by the patch pressing force.

[0045] In the specific implementation of the DC test probe device, the control unit, as the core of the test system for control and data processing, works in conjunction with the probe device to complete the high-precision DC parameter testing task. The device has a magnetic coil 110 and a vertical resistor assembly arranged along the axial direction of the probe body. Radially, from the outside to the inside, the probe outer shell layer 130, the probe shielding layer 1301, and the probe conductive layer 1302 are arranged sequentially, with each component working collaboratively according to its function. The magnetic coil 110 is made of a high-permeability material (such as ferrite) to form a ring structure, with a high-precision transmission mechanism 1101 connected to its outer side. This transmission mechanism can be either spring-driven or electromagnetically driven. The control unit sends commands to the high-precision transmission mechanism 1101 via external control signals or PWM signals to control the opening and closing distance of the magnetic coil 110; based on the inductance calculation model... (Where μ is the permeability, N is the number of coil turns, A is the cross-sectional area of ​​the magnetic circuit, and d is the change in the opening and closing distance of the coil), the control unit drives the high-precision transmission mechanism 1101 to change the opening and closing state of the magnetic coil 110, thereby realizing the dynamic adjustment of the inductance in the range of 10nH-1μH. When the control unit issues the command to "increase the inductance", the high-precision transmission mechanism 1101 drives the magnetic coil 110 to open, the magnetic circuit length increases, the magnetic resistance increases, and the inductance increases; when it is necessary to reduce the inductance, the transmission mechanism pushes the coil to close, the magnetic circuit closes, the magnetic resistance decreases, and the inductance decreases accordingly. Moreover, the response time of this adjustment process is 10ms, which meets the control unit's requirements for dynamic adjustment of inductance in high-frequency testing scenarios.

[0046] The probe housing 130 is made of silver-plated copper and filled with absorbing material. The control unit ensures that it continuously performs its shielding function during testing through system control logic, blocking external electromagnetic interference (EMI) and creating a stable electromagnetic environment for internal signal transmission and impedance adjustment. Inside the probe housing 130, the probe shielding layer 1301 and the probe conductive layer 1302 are integrated sequentially. The probe conductive layer 1302 adopts a four-wire (Kelvin connection) design. The control unit controls the separation of the excitation and detection circuits in the test system, eliminating the influence of contact resistance on the test signal and ensuring the accuracy of test signal transmission.

[0047] The vertical resistor assembly is located between the probe conductive layer 1302 and the magnetic coil 110. Its core is a vertically structured thin-film resistor (such as a nickel-chromium thin-film resistor 1202), with a contact surface formed by gold plating through deposition or sputtering processes. The bottom is filled with an elastic material or a carbon-based elastic conductive material, and it is initially arc-shaped. The patch pressing mechanism uses a high-hardness, low-elastic-modulus material (such as a silicon nitride ceramic substrate) as the substrate, with a contact resistance of 10mΩ (pressing force of 1N) and a gold-plated surface. The control unit adjusts the patch pressing force according to the test requirements: when it is necessary to reduce the impedance, the pressing force is increased to adjust the contact area according to the requirements. (where F is the pressing force and k is the elastic coefficient) linearly expands, and the resistance value is adjusted from the high level of (10 kΩ) to the low level of (1 Ω); when the impedance needs to be increased, the pressing force is reduced, the contact area shrinks, and the resistance value rises, finally realizing the impedance adjustment within the range of (1 Ω - 10 kΩ), and the impedance matching error is (<pm1%), and the vertical resistance parasitic parameters are reduced by (90%), greatly improving the accuracy of the impedance matching of the control unit to the device under test (DUT).

[0048] In the embodiment of the present invention, the vertical resistance component sequentially includes, from bottom to top along the axial direction of the probe body:

[0049] The elastic support layer 1201, serving as the bottom support structure of the vertical resistance component;

[0050] The nickel-chromium thin film resistor 1202, disposed above the elastic support layer 1201 and having a vertical structure with its axis perpendicular to the signal transmission direction of the probe conductive layer 1302, for providing a basis for impedance adjustment;

[0051] The conductive via 1203, disposed above the nickel-chromium thin film resistor 1202, for connecting the nickel-chromium thin film resistor 1202 and the silicon nitride ceramic substrate 1204;

[0052] The silicon nitride ceramic substrate 1204, disposed above the conductive via 1203, serving as the substrate of the patch pressing mechanism;

[0053] The gold plating layer 1205 is respectively disposed on the surface of the silicon nitride ceramic substrate 1204 facing the conductive via 1203 and the contact surface of the nickel-chromium thin film resistor 1202 facing the silicon nitride ceramic substrate 1204, for reducing the contact resistance.

[0054] In an embodiment of the present invention, for example, during the implementation of the vertical resistance component of the DC test probe device, the control unit acts as the core of test control and coordinates the operation of each structure. The elastic support layer 1201 serves as the bottom support for the vertical resistor assembly. When the control unit sends a pressing force adjustment command to the patch pressing mechanism, the elastic support layer 1201 undergoes elastic deformation with the change in pressing force, providing buffer support for the nichrome thin-film resistor 1202 and ensuring the stability of resistance adjustment during the pressing process. The nichrome thin-film resistor 1202 has a vertical structure with its axis perpendicular to the signal transmission direction of the probe conductive layer 1302. The control unit adjusts the pressing force according to the test impedance requirements. For example, when testing low impedance scenarios, increasing the pressing force compresses the elastic support layer 1201, and the contact area of ​​the nichrome thin-film resistor 1202 expands linearly according to the aforementioned formula, reducing the impedance. The control unit precisely executes the adjustment through a pre-stored "pressing force-impedance" correspondence table. The conductive via 1203 serves as the signal connection between the nichrome thin-film resistor 1202 and the silicon nitride ceramic substrate 1204. The test excitation signal and detection signal transmitted by the control unit are quickly transmitted through the conductive via 1203, avoiding signal path loss and ensuring the test signal. The integrity of the signal is ensured; the silicon nitrogen ceramic substrate 1204 serves as the substrate for the patch pressing mechanism. Due to its high hardness and low elastic modulus, it maintains structural stability when the pressing mechanism is applied under the control of the control unit. The contact resistance is <10mΩ when the pressing force is 1N. The control unit controls the pressing force through a closed-loop feedback from a pressure sensor, maintaining consistent contact between the substrate and the nickel-chromium thin-film resistor 1202. A gold plating layer 1205 covers the surface of the silicon nitrogen ceramic substrate 1204 facing the conductive via 1203 and the contact surface of the nickel-chromium thin-film resistor 1202 facing the substrate. The control unit calibrates the contact resistance before testing, utilizing the low contact resistance of the gold plating layer 1205 to ensure signal transmission efficiency. If an abnormal increase in contact resistance is detected, the control unit triggers a maintenance command to achieve reliable maintenance of the vertical resistor assembly. Under the control unit's scheduling, the entire vertical resistor assembly achieves an impedance adjustment range of 1Ω-10kΩ and an impedance matching error of <±1% through the functional coordination of each layer, meeting the requirements of high-precision DC testing.

[0055] In this embodiment of the invention, the silicon nitrogen ceramic substrate 1204 is directly connected to the probe conductive layer 1302 by a pressing process;

[0056] The contact area between the silicon nitrogen ceramic substrate 1204 and the nickel-chromium thin film resistor 1202 varies with the patch pressing force to adjust the impedance value of the nickel-chromium thin film resistor 1202.

[0057] In this embodiment of the invention, for example, during the operation of the DC test probe device, the control unit dominates the connection and impedance adjustment process of the silicon nitride ceramic substrate 1204. The silicon nitride ceramic substrate 1204 is directly connected to the probe conductive layer 1302 via a crimping process. The control unit controls the crimping mechanism to apply pressure, utilizing the high hardness and low elastic modulus of the substrate to ensure that the contact resistance is <10mΩ when the crimping force reaches 1N, thus laying a solid physical connection foundation for stable signal transmission. Simultaneously, the control unit adjusts the patch crimping force according to the test impedance requirements, causing the contact area between the silicon nitride ceramic substrate 1204 and the nickel-chromium thin-film resistor 1202 to change with the crimping force: when the crimping force increases, the elastic support layer 1201 deforms, causing the contact area to expand linearly according to the aforementioned formula, and the impedance of the nickel-chromium thin-film resistor 1202 decreases; when the crimping force decreases, the contact area shrinks and the impedance increases. The control unit uses a pre-stored "crimping force-contact area-impedance" correspondence table to precisely control the pressure, achieving impedance adjustment within the range of 1Ω-10kΩ to match the impedance requirements of the tested link.

[0058] In this embodiment of the invention, the magnetic coil 110 is made of a high permeability material;

[0059] The high-precision transmission mechanism 1101 is connected to the outside of the magnetic coil 110;

[0060] The opening and closing distance of the magnetic coil 110 has a linear or nonlinear mapping relationship with the inductance, and the high-precision transmission mechanism 1101 is any one of a mechanical spring, an electromagnet, or a piezoelectric ceramic actuator.

[0061] In this embodiment of the invention, exemplaryly, during the operation of the DC test probe device, the control unit dominates the inductance adjustment process of the magnetic coil 110. The magnetic coil 110 is made of a high-permeability material such as ferrite, and its outer side is connected to a high-precision transmission mechanism 1101. The control unit selects the type of transmission mechanism according to the test scenario: if it is a mechanical spring, it sends a control signal to drive the spring to extend or retract to change the opening and closing distance of the coil; if it is an electromagnet, it adjusts the current to achieve magnetic attraction; if it is a piezoelectric ceramic actuator, it outputs an electrical signal to cause its deformation to drive the coil to move. The opening and closing distance of the magnetic coil 110 and the aforementioned inductance have a linear or nonlinear mapping relationship based on the aforementioned formula. The control unit pre-calibrates this mapping relationship on a standard inductance tester to generate a lookup table (LUT). During testing, according to the inductance requirements (e.g., if the inductance needs to be reduced for high-frequency testing, the transmission mechanism is driven to reduce the opening and closing distance of the coil, so that the magnetic circuit is closed, the magnetic resistance is reduced, and the inductance is reduced accordingly; if the inductance needs to be increased, the operation is reversed), the transmission mechanism is precisely called to adjust the coil state, so as to achieve dynamic control of the inductance in the range of 10nH-1μH, with a response time of less than 10ms, which meets the requirements of dynamic inductance adjustment for high-frequency testing.

[0062] In this embodiment of the invention, the probe outer shell layer 130 is made of copper plated with silver and wraps around the probe shielding layer 1301 along the radial direction of the probe;

[0063] The probe shielding layer 1301 and the probe outer shell layer 130 are filled with a microwave absorbing material, which works in conjunction with the probe shielding layer 1301 to enhance the shielding effect against external electromagnetic interference.

[0064] The probe conductive layer 1302 is located radially along the probe inside the probe shielding layer 1301.

[0065] In this embodiment of the invention, the control unit, by way of example, controls the electromagnetic shielding and signal transmission protection of the probe outer shell layer 130 and its internal structure. The probe outer shell layer 130 is made of copper-plated silver material that radially wraps around the probe shielding layer 1301. The control unit utilizes the electromagnetic shielding properties of this material to construct an anti-interference basic structure. The space between the outer shell layer and the shielding layer is filled with absorbing material. The control unit uses system control to make the absorbing material work in conjunction with the shielding layer to absorb and reflect external electromagnetic interference (EMI) and enhance the shielding effect. The probe conductive layer 1302 is located inside the shielding layer. When the control unit schedules the transmission of the test signal in the conductive layer, it relies on the low-interference environment created by the shielding layer and the absorbing material to ensure the accuracy of signal transmission and reduce the impact of parasitic interference on the test.

[0066] In this embodiment of the invention, the probe conductive layer 1302 is connected by a four-wire Kelvin connection, which is used to separate the excitation end and the detection end inside the probe conductive layer 1302 to eliminate the influence of contact resistance.

[0067] In this embodiment of the invention, for example, the control unit, relying on the four-wire Kelvin connection design of the probe conductive layer 1302, precisely schedules the test signal transmission path during the DC testing process. The excitation signal and detection signal are respectively assigned to independent excitation and detection lines within the conductive layer, separating the current transmission and voltage detection paths. When testing devices such as semiconductor chips, the control unit drives the excitation end to apply a test current and simultaneously controls the detection end to acquire the voltage. By utilizing the line separation characteristic, interference from contact resistance voltage drop on the detection results is avoided, ensuring accurate acquisition of parameters such as voltage and current, supporting high-precision testing requirements such as <±1% impedance matching error, and guaranteeing the reliability of DC testing.

[0068] In this embodiment of the invention, the elastic support layer 1201 is located below the nickel-chromium thin film resistor 1202 and is made of elastic material or carbon-based elastic conductive material, used to support the nickel-chromium thin film resistor 1202 and assist in current transmission.

[0069] In this embodiment of the invention, for example, when the control unit adjusts the impedance of the vertical resistor assembly, the elastic support layer 1201 is located below the nickel-chromium thin-film resistor 1202 and is made of elastic or carbon-based elastic conductive material. When the control unit drives the patch pressing mechanism to apply a pressing force, the elastic support layer 1201 elastically deforms with the pressure, firmly supporting the nickel-chromium thin-film resistor 1202; at the same time, the carbon-based elastic conductive material (or elastic material combined with gold-plated contact surface) establishes a path for the test signal, assisting current transmission between the nickel-chromium thin-film resistor 1202 and the upper and lower layers, ensuring continuous and efficient signal transmission during impedance adjustment, and achieving precise control of the impedance range of 1Ω-10kΩ.

[0070] In this embodiment of the invention, the magnetic coil 110 and the vertical resistor assembly are independently arranged along the probe axis, and both can be independently detached along the probe axis.

[0071] In an exemplary embodiment of the invention, when the control unit coordinates the operation and maintenance of the DC test probe device, the magnetic coil 110 and the vertical resistor assembly are independently set along the probe axis. During the testing phase, the control unit schedules them separately: the magnetic coil 110 is driven by the high-precision transmission mechanism 1101 to adjust the inductance, and the vertical resistor assembly adjusts the impedance by the patch pressing force. The functions of the two do not interfere with each other. When the device needs maintenance or component replacement, the standardized interface is driven to execute the disassembly command, and the magnetic coil 110 and the vertical resistor assembly can be removed independently along the axis. If the performance of the magnetic coil 110 deteriorates, the control unit guides the rapid replacement of the new coil. If the vertical resistor needs calibration, it is disassembled and repaired separately, ensuring modular maintenance efficiency and continuous operation of the test system.

[0072] The nickel-chromium thin-film resistor 1202 located above the elastic support layer 1201 has a resistance value adjustable range of 1Ω-10kΩ and a parasitic capacitance of <0.1pF.

[0073] In this embodiment of the invention, for example, when the DC test probe device is running, the control unit, as the core control unit of the test process, adjusts the resistance and ensures the performance of parasitic capacitance for the nickel-chromium thin-film resistor 1202 above the elastic support layer 1201. When testing low-impedance devices (such as a certain power chip), the control unit calls the "pressure-contact area-resistance value" mapping table and sends an instruction to the patch pressing mechanism to increase the pressure; the elastic support layer 1201 deforms under pressure, causing the contact area between the nickel-chromium thin-film resistor 1202 and the silicon nitride ceramic substrate 1204 to expand linearly, and the resistance decreases from 10kΩ to 1Ω. The closed-loop feedback of the pressure sensor ensures accurate adjustment. When testing high-impedance devices (such as RF circuit boards), the control unit reduces the pressure, the elastic support layer 1201 rebounds, causing the contact area to shrink, and the resistance rises back to 10kΩ.

[0074] To address parasitic capacitance, the nickel-chromium thin-film resistor 1202 employs a vertical structure (axis perpendicular to the signal transmission direction), combined with optimized layout including the elastic support layer 1201. During control unit initialization, parasitic parameters are calibrated using a vector network analyzer, leveraging material and structural characteristics to limit parasitic capacitance to within 0.1 pF. During testing, if parasitic capacitance approaches the threshold, the control unit triggers the probe shielding layer 1301 and absorbing material for synergistic reinforcement. The copper-plated silver shell and absorbing material suppress stray electric fields, ensuring compliance with parasitic capacitance regulations across the entire impedance range. When testing high-sensitivity analog chips, the control unit adjusts the clamping force according to chip requirements (e.g.), ensuring precise resistor matching. The vertical structure and shielding design keep parasitic capacitance well below 0.1 pF, eliminating capacitance interference in signal transmission. The control unit's data accurately reflects chip characteristics, supporting stable performance throughout the entire testing process.

[0075] Please refer to the following: Figure 2 , Figure 2 A schematic diagram of the architecture of a DC testing system provided in an embodiment of the present invention includes:

[0076] The test source module is used to output test signals as well as digital input and output control signals;

[0077] As described above, the DC test probe device receives the test signal output by the test source meter module through the power supply harness and receives the digital input and output control signals through the control harness.

[0078] A probe station is used to carry the device under test, and the DC test probe device cooperates with the probe station to perform DC parameter testing on the device under test.

[0079] In this embodiment of the invention, the control unit, as the core of the DC test system, first schedules the test source module (E1) to output test signals and digital input / output (DIO) control signals. These signals are transmitted to the DC test probe device (K1) via power and control harnesses. For the DC test probe device, the control unit sends instructions to the high-precision transmission mechanism 1101 of the magnetic coil 110 via the control harness according to the test requirements of the device under test (e.g., a certain RF circuit board). If the inductance needs to be adjusted to 300nH to adapt to the high-frequency test scenario, the transmission mechanism drives the magnetic coil 110, made of high permeability material, to adjust the opening and closing distance, thereby achieving dynamic inductance control based on the aforementioned formula. For the vertical resistor assembly, the control unit adjusts the patch pressing force to change the contact area between the nickel-chromium thin film resistor 1202 and the silicon nitride ceramic substrate 1204 according to the circuit board impedance matching requirements (e.g., 1kΩ impedance). Relying on the deformation of the elastic support layer 1201 and the low contact resistance characteristics of the gold plating layer 1205, the resistance value is precisely adjusted to the target range. Simultaneously, the control unit controls the probe station (E2) to precisely carry and position the device under test, ensuring stable contact between the DC test probe and the device pins. During testing, the probe conductive layer 1302 uses a four-wire Kelvin connection to separate the excitation and detection ends. The control unit synchronously acquires the excitation current and detection voltage. External electromagnetic interference is suppressed by the probe shielding layer 1301 (copper-plated silver shell with absorbing material). Combined with parameter optimization of the magnetic coil 110 and vertical resistor assembly, the effects of parasitic capacitance and contact resistance are eliminated. Finally, high-precision testing of the circuit board's DC parameters (such as insulation resistance and DC voltage drop) is completed. The entire process relies on the coordinated scheduling of the test source meter, probe device, and probe station by the control unit to ensure efficient and reliable testing.

[0080] For illustrative purposes, the foregoing description has been made with reference to specific embodiments. However, the foregoing illustrative discussions are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. Numerous modifications and variations are possible in accordance with the foregoing teachings. These embodiments were chosen and described in order to best illustrate the principles of the present disclosure and its practical application, thereby enabling those skilled in the art to best utilize the disclosure and to employ various embodiments with different modifications to suit a particular intended application.

Claims

1. A DC test probe device, characterized in that, include: Magnetic suction coil and vertical resistor assembly arranged along the axial direction of the probe body; A probe outer shell layer that wraps around the probe body radially. A high-precision transmission mechanism is connected to the outside of the magnetic coil to drive the magnetic coil to perform opening and closing actions to adjust the probe inductance. The probe outer shell layer has a probe shielding layer and a probe conductive layer integrated from the outside to the inside. The probe shielding layer is used to shield external electromagnetic interference, and the probe conductive layer is used to transmit test signals. The vertical resistor assembly is located between the probe conductive layer and the magnetic coil, and is used to adjust the probe impedance by the patch pressing force; The vertical resistance assembly, from bottom to top along the axial direction of the probe body, comprises: An elastic support layer serves as the bottom support structure for the vertical resistor assembly; A nickel-chromium thin-film resistor is disposed above the elastic support layer and has a vertical structure with its axis perpendicular to the signal transmission direction of the probe conductive layer, serving as a basis for impedance adjustment. A conductive via is disposed above the nickel-chromium thin-film resistor to connect the nickel-chromium thin-film resistor to the silicon nitride ceramic substrate; A silicon nitrogen ceramic substrate is disposed above the conductive via, serving as the substrate for the chip bonding mechanism; A gold plating layer is respectively disposed on the surface of the silicon nitrogen ceramic substrate facing the conductive via and on the contact surface of the nickel-chromium thin film resistor facing the silicon nitrogen ceramic substrate, for the purpose of reducing contact resistance.

2. The DC test probe device according to claim 1, characterized in that, The nitrogen-silicon ceramic substrate is directly connected to the probe conductive layer via a press-fit process. The contact area between the silicon nitrogen ceramic substrate and the nickel-chromium thin film resistor varies with the patch pressing force to adjust the impedance value of the nickel-chromium thin film resistor.

3. The DC test probe device according to claim 1, characterized in that, The magnetic coil is made of a high permeability material; The high-precision transmission mechanism is connected to the outside of the magnetic coil; The opening and closing distance of the magnetic coil has a linear or nonlinear mapping relationship with the inductance, and the high-precision transmission mechanism is any one of a mechanical spring, an electromagnet, or a piezoelectric ceramic actuator.

4. The DC test probe device according to claim 1, characterized in that, The probe outer shell is made of silver-plated copper and wraps around the probe shielding layer radially. The probe shielding layer and the probe outer shell layer are filled with a microwave absorbing material, which works in conjunction with the probe shielding layer to enhance the shielding effect against external electromagnetic interference. The probe conductive layer is located radially from the probe inside the probe shielding layer.

5. The DC test probe device according to claim 1, characterized in that, The probe conductive layer uses a four-wire Kelvin connection to separate the excitation end and the detection end inside the probe conductive layer to eliminate the influence of contact resistance.

6. The DC test probe device according to claim 1, characterized in that, The elastic support layer is located below the nickel-chromium thin-film resistor and is made of elastic material. It is used to support the nickel-chromium thin-film resistor and assist in current transmission.

7. The DC test probe device according to claim 1, characterized in that, The magnetic coil and the vertical resistor assembly are independently arranged along the probe axis, and both can be independently detached along the probe axis.

8. The DC test probe device according to claim 1, characterized in that, The nickel-chromium thin-film resistor located above the elastic support layer has a resistance value adjustable range of 1Ω-10kΩ and a parasitic capacitance of <0.1pF.

9. A DC testing system, characterized in that, include: The test source module is used to output test signals as well as digital input and output control signals; The DC test probe device as described in any one of claims 1-8, wherein the DC test probe device receives the test signal output by the test source meter module through a power supply harness and receives the digital input and output control signals through a control harness; A probe station is used to carry the device under test, and the DC test probe device cooperates with the probe station to perform DC parameter testing on the device under test.

Images