Direct current test probe device and direct current test system

Abstract

The invention discloses a direct-current test probe device and a direct-current test system. The direct-current test probe device is provided with a magnetic suction coil and a vertical resistor assembly along the axial direction of a probe main body, and is provided with a probe shell layer along the radial direction; the outer side of the magnetic coil is connected with a high-precision transmission mechanism, and the inductance value is dynamically adjusted by driving the coil to open and close; a probe shielding layer and a probe conducting layer are integrated in the probe shell layer from outside to inside; the vertical resistor assembly is located between the probe conducting layer and the magnetic attraction coil, and the impedance of the probe is adjusted through the patch crimping force. The device realizes integrated accurate regulation and control of inductance and impedance, reduces parasitic interference, and adapts to DC parameter test requirements of multiple scenes such as a semiconductor chip and a circuit board.

Description

Technical Field

[0001] The present invention relates to the field of electronic testing, and in particular to a direct current (DC) test probe device and a DC test system. Background Art

[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. The fixed inductance design cannot adapt to a wide range of test scenarios, and parasitic inductance can easily cause signal distortion during high-frequency testing. Second, impedance matching is insufficient. Traditional series / parallel resistance adjustment methods introduce additional parasitic capacitance and inductance, interfering with the impedance characteristics of the link under test (DUT). Third, the complex and redundant structure relies on external circuits to adjust inductance and impedance, resulting in larger system size and higher costs. Summary of the Invention

[0003] The object of the present invention is to provide a DC test probe device and a DC test system.

[0004] In a first aspect, an embodiment of the present invention provides a DC test probe device, comprising:

[0005] A magnetic coil and a vertical resistance assembly are arranged along the axial direction of the probe body;

[0006] A probe shell layer radially wrapped around the probe body;

[0007] The outer side of the magnetic coil is connected to a high-precision transmission mechanism for driving the magnetic coil to perform an opening and closing action to adjust the probe inductance;

[0008] The probe shielding layer and the probe conductive layer are sequentially integrated in the probe shell layer 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 the test signal;

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

[0010] In a possible implementation, the vertical resistor assembly includes, in order from bottom to top along the axial direction of the probe body:

[0011] an elastic supporting layer, serving as a bottom supporting structure of 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, and is used to provide a basis for impedance adjustment;

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

[0014] A silicon nitride ceramic substrate is provided above the conductive via and serves as a substrate for the patch crimping mechanism;

[0015] The gold-plated layers are respectively arranged on the surface of the silicon nitride ceramic substrate facing the conductive via hole and the contact surface of the nickel-chromium thin film resistor facing the silicon nitride ceramic substrate, so as to reduce the contact resistance.

[0016] In a possible implementation, the silicon nitride ceramic substrate is directly connected to the probe conductive layer through a compression process;

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

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

[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 driver.

[0021] In a possible embodiment, the probe outer shell layer is made of copper-plated silver material and wraps the probe shielding layer along the radial direction of the probe;

[0022] The probe shielding layer and the probe outer shell layer are filled with an absorbing material, and the absorbing material cooperates with the probe shielding layer to enhance the shielding effect of external electromagnetic interference;

[0023] The probe conductive layer is located inside the probe shielding layer along the radial direction of the probe.

[0024] In a possible implementation, the probe conductive layer adopts 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.

[0025] In a 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, and is used to support the nickel-chromium thin film resistor and assist current transmission.

[0026] In a possible implementation, the magnetic coil and the vertical resistance assembly are independently arranged along the axial direction of the probe, and both can be independently disassembled along the axial direction of the probe.

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

[0028] In a second aspect, an embodiment of the present invention provides a DC test system, comprising:

[0029] Test source meter module, used for outputting test signals and digital input and output control signals;

[0030] The DC test probe device according to any one of the first aspects, wherein the DC test probe device receives the test signal output by the test source meter module through a power harness, and receives the digital input and output control signal through a control harness;

[0031] The 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 with the existing technology, the present invention provides the following beneficial effects: a DC test probe device and DC test system disclosed in the present invention are provided, wherein the DC test probe device is provided with a magnetic coil and a vertical resistor assembly along the axial direction of the probe body, and a probe outer shell layer is provided along the radial direction; a high-precision transmission mechanism is connected to the outer side of the magnetic coil, and the inductance is dynamically adjusted by driving the coil to open and close; the probe shielding layer and the probe conductive layer are integrated inside the probe outer shell 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 crimping force. This device achieves integrated and precise control of inductance and impedance, reduces parasitic interference, and adapts to the DC parameter testing needs of multiple scenarios such as semiconductor chips and circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly describes the drawings required for use in the embodiments. It should be understood that the following drawings illustrate only certain embodiments of the present invention and should not be construed as limiting the scope of the present invention. Those skilled in the art can, without inventive effort, derive other relevant drawings from these drawings.

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

[0035] Figure 2 A schematic diagram of the architecture of a DC test system provided by an embodiment of the present invention.

[0036] Figure 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 - nitrogen silicon ceramic substrate, 1205 - gold plating layer, 130 - probe shell layer, 1301 - probe shielding layer, 1302 - probe conductive layer. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present invention. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, not all of them. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

[0038] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] In order to solve the technical problems in the above background technology, Figure 1 The following is a structural diagram of a DC test probe device provided by an embodiment of the present disclosure. The DC test probe device is 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 resistance assembly are arranged along the axial direction of the probe body;

[0041] A probe shell layer 130 radially wrapped around the probe body;

[0042] The outer side of the magnetic coil 110 is connected to a high-precision transmission mechanism 1101 for driving the magnetic coil 110 to perform an opening and closing action to adjust the probe inductance;

[0043] The probe housing layer 130 is sequentially integrated with a probe shielding layer 1301 and a probe conductive layer 1302 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 resistance component is located between the probe conductive layer 1302 and the magnetic coil 110 and is used to adjust the probe impedance through the patch pressing force.

[0045] During the specific implementation of the DC test probe device, the control unit serves as the control and data processing core of the test system, and cooperates with the probe device to complete the high-precision DC parameter test task. The device sets a magnetic coil 110 and a vertical resistance component along the axial direction of the probe body, and sequentially configures the probe shell layer 130, the probe shielding layer 1301 and the probe conductive layer 1302 in the radial direction from the outside to the inside, and each component works together according to its function. Among them, the magnetic coil 110 is made of a ring structure using a high magnetic permeability material (such as ferrite), and its outer side is connected to a high-precision transmission mechanism 1101. The transmission mechanism can be driven by a spring or an electromagnetic drive. The control unit sends instructions to the high-precision transmission mechanism 1101 through an external control signal or a PWM signal to control the opening and closing distance of the magnetic coil 110; according to the inductance calculation model (where μ is the magnetic 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 dynamic adjustment of the inductance within the range of 10nH-1μH. When the control unit issues an "increase inductance" instruction, 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 the inductance needs to be reduced, the transmission mechanism pushes the coils to merge, the magnetic circuit closes, the magnetic resistance decreases, and the inductance decreases accordingly. The response time of this adjustment process is 10ms, which meets the control unit's requirements for dynamic adjustment of inductance in high-frequency test scenarios.

[0046] The probe's outer shell 130 is made of silver-plated copper and filled with absorbing material. The control unit, through system control logic, ensures that its shielding function continues to function during testing, blocking external electromagnetic interference (EMI) and creating a stable electromagnetic environment for internal signal transmission and impedance adjustment. The probe shielding layer 1301 and the probe conductive layer 1302 are integrated within the probe's outer shell 130. The probe conductive layer 1302 utilizes a four-wire (Kelvin connection) design. The control unit separates the excitation and detection circuits within the test system, eliminating the effects of contact resistance on the test signal and ensuring accurate test signal transmission.

[0047] The vertical resistor component is located between the probe conductive layer 1302 and the magnetic coil 110. Its core is a vertical structure thin film resistor (such as nickel-chromium thin film resistor 1202). The contact surface is formed by gold plating through deposition or sputtering process, and the bottom is filled with elastic material or carbon-based elastic conductive material. The initial state is arc-shaped; the patch pressing mechanism uses a high hardness and low elastic modulus material (such as silicon nitride ceramic substrate) as the substrate, with a contact resistance of 10mΩ (pressing force 1N) and gold plating on the surface. The control unit adjusts the patch pressing force according to the test requirements: when the impedance needs to be reduced, the pressing force is increased to make the contact area according to (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 rebounds, finally realizing the impedance adjustment within the range of (1 Ω - 10 kΩ), and the impedance matching error (<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 the embodiment of the present invention, exemplarily, during the implementation of the vertical resistance assembly of the DC test probe device, the control unit serves as a test control core to coordinate the operation of various structures. The elastic support layer 1201 serves as the bottom support of the vertical resistor component. When the control unit sends a crimping force adjustment instruction to the patch crimping mechanism, the elastic support layer 1201 produces elastic deformation as the crimping force changes, providing buffer support for the nickel-chromium thin film resistor 1202, and ensuring the stability of the resistance adjustment during the crimping process; the nickel-chromium thin film resistor 1202 is a vertical structure and its axis is perpendicular to the signal transmission direction of the probe conductive layer 1302. The control unit adjusts the crimping force according to the test impedance requirements. For example, when testing a low-impedance scenario, the crimping force is increased to compress the elastic support layer 1201, and the contact area of ​​the nickel-chromium thin film resistor 1202 is linearly expanded according to the above formula, and the impedance is reduced. The control unit accurately performs the adjustment through the pre-stored "crimping force-impedance" correspondence table; the conductive via 1203 assumes the signal connection function between the nickel-chromium thin film resistor 1202 and the nitrogen silicon ceramic substrate 1204. The test excitation signal and the detection signal transmitted by the control unit are quickly transmitted through the conductive via 1203 to avoid signal path loss and ensure the test signal The silicon nitride ceramic substrate 1204 serves as the substrate of the patch crimping mechanism. With its high hardness and low elastic modulus, it maintains structural stability when the control unit controls the force of the crimping mechanism. When the crimping force is 1N, the contact resistance is <10mΩ. The control unit controls the crimping force through a pressure sensor feedback closed-loop to maintain the contact consistency between the substrate and the nickel-chromium thin film resistor 1202. The gold-plated layer 1205 covers 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 substrate. The control unit calibrates the contact resistance before testing and uses the low contact resistance of the gold-plated layer 1205 to ensure signal transmission efficiency. If an abnormal increase in contact resistance is detected, the control unit triggers a maintenance instruction to achieve reliability maintenance of the vertical resistor assembly. Under the control of the control unit, 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 structure, meeting the requirements of high-precision DC testing.

[0055] In the embodiment of the present invention, the silicon nitride ceramic substrate 1204 is directly connected to the probe conductive layer 1302 through a compression process;

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

[0057] In an embodiment of the present invention, illustratively, during operation of the DC test probe device, a control unit directs 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 through a crimping process. The control unit controls the crimping mechanism to apply pressure, leveraging the substrate's high hardness and low elastic modulus to ensure a contact resistance of less than 10mΩ when the crimping force reaches 1N, thereby providing a solid physical connection foundation for stable signal transmission. Simultaneously, the control unit adjusts the patch crimping force based on 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 deformation of the elastic support layer 1201 causes the contact area to expand linearly according to the aforementioned formula, reducing the impedance of the nickel-chromium thin film resistor 1202. When the crimping force decreases, the contact area decreases and the impedance increases. The control unit uses a pre-stored "crimping force-contact area-impedance" correspondence table to precisely control the voltage, achieving impedance adjustment within a range of 1Ω-10kΩ to match the impedance requirements of the link under test.

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

[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 driver.

[0061] In an embodiment of the present invention, for example, during operation of the DC test probe device, a control unit directs the inductance adjustment process of the magnetic coil 110. The magnetic coil 110 is made of a high-permeability material such as ferrite, and is externally connected to a high-precision transmission mechanism 1101. The control unit selects the transmission mechanism type based on the test scenario: if it is a mechanical spring, a control signal is sent to drive the spring to expand and contract, thereby changing the coil's opening and closing distance; if it is an electromagnet, the current is regulated to achieve magnetic attraction; if it is a piezoelectric ceramic actuator, an electrical signal is output to cause the actuator to deform, thereby driving the coil. 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 the mapping relationship under a standard inductance tester to generate a lookup table (LUT). During the test, according to the inductance requirements (for example, if the high-frequency test needs to reduce the inductance, 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 reverse operation is performed), the transmission mechanism is accurately called to adjust the coil state, so that the inductance is dynamically controlled in the range of 10nH-1μH, and the response time is less than 10ms, which meets the requirements of high-frequency testing for dynamic inductance adjustment.

[0062] In the embodiment of the present invention, the probe outer shell layer 130 is made of copper-plated silver material and wraps 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 an absorbing material, and the absorbing material cooperates with the probe shielding layer 1301 to enhance the shielding effect of external electromagnetic interference;

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

[0065] In an embodiment of the present invention, the control unit exemplarily controls the electromagnetic shielding and signal transmission assurance of the probe outer shell layer 130 and the internal structure. The probe outer shell layer 130 is made of copper-plated silver material and radially wraps the probe shielding layer 1301. The control unit uses the electromagnetic shielding properties of its material to construct an anti-interference infrastructure; the outer shell layer and the shielding layer are filled with absorbing material. The control unit controls the system to make the absorbing material cooperate with the shielding layer to absorb and reflect external electromagnetic interference (EMI) and enhance the shielding effect; the probe conductive layer 1302 is located on the inner side of the shielding layer. When the control unit schedules the test signal to be transmitted 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 the embodiment of the present invention, the probe conductive layer 1302 adopts 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 an embodiment of the present invention, exemplarily, the control unit accurately schedules the test signal transmission path in the DC test process based on the four-wire Kelvin connection design of the probe conductive layer 1302. The excitation signal and the detection signal are respectively allocated to independent excitation end and detection end circuits in the conductive layer, so that the current transmission and voltage detection paths are separated from each other. When testing devices such as semiconductor chips, the control unit drives the excitation end to apply the test current and synchronously controls the detection end to collect the voltage. The line separation feature is used to avoid the interference of the contact resistance voltage drop on the test results, ensuring the accurate collection of parameters such as voltage and current, supporting high-precision testing requirements such as <±1% impedance matching error, and ensuring the reliability of DC testing.

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

[0069] In an embodiment of the present invention, for example, when the control unit adjusts the impedance of the vertical resistor component, 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 crimping mechanism to apply crimping 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 with gold-plated contact surface) builds a path for the test signal, assisting the current transmission between the nickel-chromium thin film resistor 1202 and the upper and lower structures, ensuring continuous and efficient signal transmission during the impedance adjustment process, and cooperating to achieve precise control of the impedance range of 1Ω-10kΩ.

[0070] In the embodiment of the present invention, the magnetic coil 110 and the vertical resistance assembly are independently arranged along the axial direction of the probe, and both can be independently disassembled along the axial direction of the probe.

[0071] In an embodiment of the present invention, exemplarily, 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 arranged along the axis of the probe, and the control unit dispatches them separately during the test phase: the magnetic coil 110 is driven by the high-precision transmission mechanism 1101 to adjust the inductance, and the vertical resistor assembly uses the patch pressing force to adjust the impedance, and the two functions do not interfere with each other; when the device needs maintenance or component replacement, the standardized interface is driven to execute the disassembly instruction, and the magnetic coil 110 and the vertical resistor assembly can be independently removed along the axial direction. If the performance of the magnetic coil 110 decays, the control unit guides the rapid replacement of the new coil; if the vertical resistor needs to be calibrated, it is disassembled and repaired separately to ensure the modular maintenance efficiency and the continuous operation of the test system.

[0072] The nickel-chromium thin film resistor 1202 located above the elastic supporting layer 1201 has a resistance adjustment range of 1Ω-10kΩ, and a parasitic capacitance of less than 0.1pF.

[0073] In an embodiment of the present invention, exemplarily, when the DC test probe device is running, the control unit serves as the core control unit of the test process, and realizes resistance adjustment and parasitic capacitance performance assurance 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 "pressing force-contact area-resistance value" mapping table and sends an instruction to increase the pressing force to the patch pressing mechanism; the elastic support layer 1201 is deformed by pressure, driving the contact area between the nickel-chromium thin film resistor 1202 and the nitrogen silicon ceramic substrate 1204 to linearly expand, and the resistance is reduced from 10kΩ to 1Ω, and 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 pressing force, the elastic support layer 1201 rebounds to shrink the contact area, and the resistance returns to 10kΩ.

[0074] To address parasitic capacitance, the nickel-chromium thin film resistor 1202 adopts a vertical structure (the axis is perpendicular to the signal transmission direction), combined with layout optimization such as the elastic support layer 1201. The control unit uses a vector network analyzer to calibrate the parasitic parameters during initialization, and limits the parasitic capacitance to within 0.1pF by leveraging the material and structural characteristics. During the test, if the parasitic capacitance approaches the threshold, the control unit triggers the probe shielding layer 1301 and the absorbing material to synergistically strengthen, using the copper-silver-plated shell and absorbing material to suppress stray electric fields and ensure parasitic capacitance compliance across the entire impedance range. For example, when testing high-sensitivity analog chips, the control unit adjusts the crimping force according to the chip requirements (such as) to ensure precise matching of the resistors; the vertical structure and shielding design keep the parasitic capacitance far below 0.1pF, ensuring there is no capacitance interference in signal transmission, and the data collected by the control unit accurately reflects the chip characteristics, supporting stable performance throughout the entire test process.

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

[0076] Test source meter module, used for outputting test signals and digital input and output control signals;

[0077] The DC test probe device as described above receives the test signal output by the test source meter module through the power harness and receives the digital input and output control signals through the control harness;

[0078] The 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 an embodiment of the present invention, the control unit serves as the control core of the DC test system, and first schedules the test source meter module (E1) to output test signals and digital input and output (DIO) control signals. These signals are transmitted to the DC test probe device (K1) through the power harness and the control harness. For the DC test probe device, the control unit sends instructions to the high-precision transmission mechanism 1101 of the magnetic coil 110 through the control harness based on the test requirements of the device under test (such as 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, and realizes dynamic inductance regulation based on the above formula; for the vertical resistor component, the control unit adjusts the chip pressing force to change the contact area between the nickel-chromium thin film resistor 1202 and the nitrogen silicon ceramic substrate 1204 according to the impedance matching requirements of the circuit board (such as 1kΩ impedance), and relies on the deformation of the elastic support layer 1201 and the low contact resistance characteristics of the gold-plated layer 1205 to accurately adjust the resistance value to the target range. At the same time, 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 the test, the probe conductive layer 1302 uses a four-wire Kelvin connection to separate the excitation and detection ends. The control unit simultaneously collects the excitation current and detection voltage, and uses the probe shielding layer 1301 (copper-plated silver shell with absorbing material) to suppress external electromagnetic interference. Combined with the parameter optimization of the magnetic coil 110 and the vertical resistor component, the effects of parasitic capacitance and contact resistance are eliminated, ultimately completing high-precision testing of the circuit board's DC parameters (such as insulation resistance and DC voltage drop). The entire process relies on the control unit's coordinated scheduling of the test source meter, probe device, and probe station to ensure an efficient and reliable test process.

[0080] For illustrative purposes, the foregoing description has been made with reference to specific embodiments. However, the above illustrative discussion is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. Numerous modifications and variations are possible in light of the above teachings. These embodiments have been selected 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 present disclosure and to utilize various embodiments with various modifications as appropriate for the specific application contemplated.

Claims

1. A DC test probe device, characterized in that: include: A magnetic coil and a vertical resistance assembly are arranged along the axial direction of the probe body; A probe shell layer radially wrapped around the probe body; The outer side of the magnetic coil is connected to a high-precision transmission mechanism for driving the magnetic coil to perform an opening and closing action to adjust the probe inductance; The probe shielding layer and the probe conductive layer are sequentially integrated in the probe shell layer 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 the test signal; The vertical resistance component is located between the probe conductive layer and the magnetic coil, and is used to adjust the probe impedance through the patch pressing force.

2. The DC test probe device according to claim 1, characterized in that: The vertical resistance assembly includes, from bottom to top along the axial direction of the probe body: an elastic supporting layer, serving as a bottom supporting structure of 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, and is used to provide a basis for impedance adjustment; A conductive via is provided above the nickel-chromium thin film resistor and is used to connect the nickel-chromium thin film resistor and the silicon nitride ceramic substrate; A silicon nitride ceramic substrate is provided above the conductive via and serves as a substrate for the patch crimping mechanism; The gold-plated layers are respectively arranged on the surface of the silicon nitride ceramic substrate facing the conductive via hole and the contact surface of the nickel-chromium thin film resistor facing the silicon nitride ceramic substrate, so as to reduce the contact resistance.

3. The DC test probe device according to claim 2, characterized in that: The silicon nitride ceramic substrate is directly connected to the probe conductive layer through a compression process; The contact area between the silicon nitride ceramic substrate and the nickel-chromium thin film resistor changes with the chip pressing force to adjust the impedance value of the nickel-chromium thin film resistor.

4. The DC test probe device according to claim 1, wherein: The magnetic coil is made of high magnetic 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 driver.

5. The DC test probe device according to claim 1, characterized in that: The probe outer shell layer is made of copper-plated silver material and wraps the probe shielding layer along the radial direction of the probe; The probe shielding layer and the probe outer shell layer are filled with an absorbing material, and the absorbing material cooperates with the probe shielding layer to enhance the shielding effect of external electromagnetic interference; The probe conductive layer is located inside the probe shielding layer along the radial direction of the probe.

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

7. The DC test probe device according to claim 2, characterized in that: The elastic supporting layer is located below the nickel-chromium thin film resistor and is made of an elastic material or a carbon-based elastic conductive material, and is used to support the nickel-chromium thin film resistor and assist current transmission.

8. The DC test probe device according to claim 1, wherein: The magnetic coil and the vertical resistance assembly are independently arranged along the axial direction of the probe, and both can be independently disassembled along the axial direction of the probe.

9. The DC test probe device according to claim 2, characterized in that: The nickel-chromium thin film resistor located above the elastic supporting layer has a resistance adjustment range of 1Ω-10kΩ, and a parasitic capacitance of <0.1pF.

10. A DC test system, characterized in that: include: Test source meter module, used for outputting test signals and digital input and output control signals; The DC test probe device according to any one of claims 1 to 9, wherein the DC test probe device receives the test signal output by the test source meter module through a power harness, and receives the digital input and output control signal through a control harness; The 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.

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