A non-contact dual-probe square resistance measurement device and method

Abstract

The present invention discloses a non-contact dual-probe square resistance measurement device and method, which belongs to the field of square resistance measurement technology. In this solution, a controller, an excitation circuit, an auxiliary circuit, a shielding circuit, and an AC power supply are set in the upper and lower probes. When detecting the square resistance value of the film layer on the upper surface of the sample, the excitation circuit of the upper probe and the auxiliary circuit of the lower probe work simultaneously. When detecting the square resistance value of the film layer on the lower surface of the sample, the auxiliary circuit of the upper probe and the excitation circuit of the lower probe work simultaneously. The on and off of the internal circuits of the upper and lower probes are controlled according to the set switching frequency, and the square resistance values ​​of the film layers on the upper and lower surfaces of the sample are measured in turn. By adopting the solution of the present invention, the square resistance of the same position on the upper and lower surfaces of the sample can be measured simultaneously without additional movement or flipping of the sample and the probe, and there is no need to purchase a new set of square resistance meters, nor is there a need for additional installation space or rotation and translation mechanisms, which not only saves costs, but also ensures detection accuracy and improves detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of square resistance measurement, and in particular to a non-contact dual-probe square resistance measurement device and method. Background Art

[0002] In the research and production of thin-film and new materials, coating the upper and lower surfaces of substrates is often necessary. Substrates are typically made of insulating materials or materials with very high sheet resistance, and the film layers on the upper and lower surfaces are often made of different materials, such as a conductor on one side and a semiconductor on the other. Consequently, there is often a significant difference in sheet resistance between the upper and lower surface films. If the film thickness is uneven, its conductive properties will be affected. In engineering, sheet resistance is often measured to determine whether the film thickness is uniform. Therefore, on the production line, the sheet resistance at the same location on the upper and lower surfaces of the specimen must be measured simultaneously to quickly assess the uniformity of the film layers on the upper and lower surfaces of the specimen.

[0003] The existing square resistance measurement technology usually adopts a non-contact dual-probe square resistance measurement device. Figure 1 As shown, this device consists of an upper probe (excitation probe) and a lower probe (auxiliary probe), with the sample positioned between the upper and lower probes. Due to space limitations, existing measurement devices cannot simultaneously measure the sheet resistance of the upper and lower surfaces of the sample at the same time. To measure the sheet resistance at the same location on the upper and lower surfaces, there are generally two methods: flipping the sample or probe, or moving the sample to the center of another set of probes. Both methods have the following drawbacks:

[0004] 1. Turn over the sample or probe:

[0005] Actuator: An additional actuator is required to flip the specimen or probe.

[0006] Time consumption: Flipping time is usually long, at least several seconds. The current production line production cycle is generally 5 pieces / second or even higher. Therefore, flipping the sample or probe cannot achieve real-time online measurement.

[0007] Accuracy issues: Flipping may cause position offset or even change the distance between the upper and lower probes and the sample, which will seriously affect the measurement accuracy and may even make it impossible to obtain accurate data.

[0008] 2. Move the sample to another set of probes:

[0009] Space requirements: Additional assembly space is required, which is difficult to achieve in some particularly compact production lines.

[0010] Increased costs: Additional probe sets increase acquisition, operation, and maintenance costs.

[0011] Precision requirements: A controller needs to be added to ensure that the sample can stay in the same position accurately, which places high demands on the accuracy of the moving device.

[0012] In summary, existing square resistance measurement methods have many shortcomings in production line applications and cannot meet the requirements of high-efficiency and high-precision measurement. Therefore, a device that can simultaneously measure the square resistance of the same position on the upper and lower surfaces of a sample on the production line is urgently needed to improve measurement efficiency and accuracy. Summary of the Invention

[0013] The technical problem to be solved by the present invention is: in view of the above-mentioned defects of the prior art, a non-contact dual-probe square resistance measurement device and method are provided, which can simultaneously measure the square resistance of the same position on the upper and lower surfaces of the sample without additional movement or flipping of the sample and the probe.

[0014] To achieve the above objectives, the present invention provides a non-contact dual-probe square resistance measurement device for simultaneously measuring the square resistance of the same position on the upper and lower surfaces of a moving sample on a production line. The sample includes a first film layer, a substrate, and a second film layer. The first film layer and the second film layer are respectively located on the upper and lower surfaces of the substrate. The non-contact dual-probe square resistance measurement device includes:

[0015] A first probe, a second probe, a main control unit, a display and an input-output unit;

[0016] The first probe, the second probe, and the display and input / output unit are respectively connected to the main control unit;

[0017] The first probe is vertically arranged above the sample, and the second probe is vertically arranged below the sample. The centers of the first probe and the second probe are in a straight line, and neither the first probe nor the second probe contacts the sample.

[0018] The first probe is provided with a first controller, a first excitation circuit, a first auxiliary circuit, a first shielding circuit, and a first AC power supply; the second probe is provided with a second controller, a second excitation circuit, a second auxiliary circuit, a second shielding circuit, and a second AC power supply;

[0019] The first auxiliary circuit and the second auxiliary circuit are both mutual inductance circuits;

[0020] The first shielding circuit and the second shielding circuit are used for electromagnetic field isolation;

[0021] The display and input-output unit is used to set measurement parameters and display measurement results;

[0022] The main control unit receives the measurement parameters set by the display and input / output unit, controls the on / off of the circuits in the first probe and the second probe through the first controller and the second controller, measures the square resistance values ​​of the first film layer and the second film layer in turn, and calculates the square resistance values ​​of the first film layer and the second film layer based on the measurement results of the first probe and the second probe.

[0023] Preferably, the first controller, under the control of the main control unit, controls the on / off connection between the first AC power supply and the first excitation circuit, the on / off connection between the first shielding circuit and the first excitation circuit, and the on / off connection between the first shielding circuit and the first auxiliary circuit;

[0024] Under the control of the main control unit, the second controller controls the on-off connection between the second AC power supply and the second excitation circuit, the on-off connection between the second shielding circuit and the second excitation circuit, and the on-off connection between the second shielding circuit and the second auxiliary circuit.

[0025] Preferably, the first shielding circuit and the second shielding circuit both include an energized shielding shell, a multi-point grounding circuit and a filtering circuit.

[0026] Preferably, the non-contact dual-probe square resistance measuring device further comprises a transmission and support device, and the transmission and support device moves the sample to a detection range of the non-contact dual-probe square resistance measuring device.

[0027] The present invention also provides a non-contact dual-probe square resistance measurement method, which is applied to the non-contact dual-probe square resistance measurement device described above, and the method comprises the following steps:

[0028] Step S1, adjusting the oscillation frequency of the excitation circuit and the height of the probe so that the penetration depth of the probe covers a portion of the substrate and does not penetrate into the film layer opposite to the sample;

[0029] Step S2, setting a switching frequency for measuring the square resistance values ​​of the first film layer and the second film layer and a detection frequency of the probe;

[0030] Step S3, controlling the on / off of the circuits in the first probe and the second probe according to the switching frequency, and measuring the square resistance of the first film layer and the second film layer in sequence;

[0031] Step S4 , calculating the square resistance of the first film layer and the square resistance of the second film layer according to the square resistances measured by the first probe and the second probe and the square resistance of the substrate.

[0032] Preferably, in step S1, the oscillation frequency of the first excitation circuit is the same as the oscillation frequency of the second excitation circuit, and the vertical distance between the first probe and the sample is the same as the vertical distance between the second probe and the sample.

[0033] Preferably, the oscillation frequency of the first excitation circuit and the second excitation circuit is 1-100 MHz.

[0034] Preferably, in step S2, the detection frequency of the first probe is the same as the detection frequency of the second probe, and the detection frequency is an integer multiple of the switching frequency.

[0035] Preferably, the specific method of step S3 is:

[0036] When measuring the square resistance of the first film layer, controlling the first controller to connect the first excitation circuit to the first AC power supply and the first shielding circuit to the first auxiliary circuit, and simultaneously controlling the second controller to disconnect the second excitation circuit from the second AC power supply and connect the second shielding circuit to the second excitation circuit;

[0037] When measuring the square resistance value of the second film layer, the first controller is controlled to disconnect the first excitation circuit from the first AC power supply and connect the first shielding circuit to the first excitation circuit, and at the same time, the second controller is controlled to connect the second excitation circuit to the second AC power supply and connect the second shielding circuit to the second auxiliary circuit.

[0038] Preferably, the specific method of step S4 is:

[0039] Assuming that the square resistance of the substrate is R0, when measuring the square resistance of the first film layer, the square resistance measured by the first probe is R1. If R0>R1, the square resistance of the first film layer RA=R1*R0 / (R0-R1); if R0<=R1, the square resistance of the first film layer RA=R1; when measuring the square resistance of the second film layer, the square resistance measured by the second probe is R2. If R0>R2, the square resistance of the second film layer RB=R2*R0 / (R0-R2); if R0<=R2, the square resistance of the second film layer RB=R2.

[0040] The present invention has the following beneficial effects: A controller, an excitation circuit, an auxiliary circuit, a shielding circuit, and an AC power supply are provided in both the upper and lower probes. The controller is used to control the on / off switching between the excitation circuit and the AC power supply, the on / off switching between the auxiliary circuit and the shielding circuit, and the on / off switching between the excitation circuit and the shielding circuit. When the shielding circuit and the auxiliary circuit are connected, only the excitation circuit operates; when the shielding circuit and the excitation circuit are connected, only the auxiliary circuit operates. When measuring the square resistance of the film layer on the upper surface of a sample, the excitation circuit of the upper probe and the auxiliary circuit of the lower probe operate simultaneously; when measuring the square resistance of the film layer on the lower surface of a sample, the auxiliary circuit of the upper probe and the excitation circuit of the lower probe operate simultaneously. The on / off switching of the internal circuits of the upper and lower probes is controlled according to a set switching frequency, and the square resistance of the film layers on the upper and lower surfaces of the sample are measured sequentially. Using the solution of the present invention, the square resistance of the same position on the upper and lower surfaces of a sample can be simultaneously measured without additional movement or flipping of the sample and probes. This eliminates the need to purchase a new square resistance meter, nor does it require additional installation space or rotation and translation mechanisms. This saves costs, ensures detection accuracy, and improves detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0042] Figure 1 Schematic diagram of the existing non-contact dual-probe square resistance measurement device and double-sided coating sample measurement.

[0043] Figure 2 Schematic diagram of the non-contact dual-probe square resistance measurement device and double-sided coating sample measurement provided by an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the internal circuit connections of the probes when the non-contact dual-probe square resistance measurement device provided by an embodiment of the present invention measures the first film layer.

[0045] Figure 4 This is a schematic diagram of the internal circuit connections of the probes when the non-contact dual-probe square resistance measurement device provided by an embodiment of the present invention measures the second film layer.

[0046] Figure 5 A schematic diagram of the excitation circuit structure provided by the non-contact dual-probe square resistance measurement device provided by an embodiment of the present invention.

[0047] Figure 6 A schematic diagram of the auxiliary circuit structure provided by the non-contact dual-probe square resistance measurement device provided by an embodiment of the present invention.

[0048] Figure 7 A schematic diagram of the steps of a non-contact dual-probe square resistance measurement method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] The sample in the present invention refers to the product produced in batches by an automated production line, and its structure is as follows Figure 1 As shown, the substrate includes a first film layer plated on the upper surface of the substrate, and a second film layer plated on the lower surface of the substrate. The square resistance of the substrate is nominal, and the square resistance of the first and second film layers also have corresponding nominal values. However, due to process and other reasons, the square resistance of the first and second film layers may still differ significantly from the nominal specifications. If the thickness of the first and second film layers is uneven, their conductive performance will be affected. Therefore, it is very important to quickly measure the square resistance of the first and second film layers to determine the thickness uniformity of the first and second film layers under the production line cycle.

[0051] The general concept of the present invention is to install a controller, an excitation circuit, an auxiliary circuit, a shielding circuit, and an AC power supply in both the upper and lower probes. The controller is used to control the on / off switching between the excitation circuit and the AC power supply, the on / off switching between the auxiliary circuit and the shielding circuit, and the on / off switching between the excitation circuit and the shielding circuit. When the shielding circuit and the auxiliary circuit are connected, only the excitation circuit operates; when the shielding circuit and the excitation circuit are connected, only the auxiliary circuit operates. When detecting the square resistance of the first film layer, the excitation circuit of the upper probe and the auxiliary circuit of the lower probe operate simultaneously. When detecting the square resistance of the second film layer, the auxiliary circuit of the upper probe and the excitation circuit of the lower probe operate simultaneously. By setting the switching frequency, the square resistance of the first and second film layers are measured sequentially.

[0052] The embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0053] like Figure 2-4 As shown, an embodiment of the present invention provides a non-contact dual-probe square resistance measurement device for simultaneously measuring the square resistance of the same position on the upper and lower surfaces of a moving sample on a production line. The sample includes a first film layer, a substrate, and a second film layer. The first film layer and the second film layer are respectively located on the upper and lower surfaces of the substrate. The non-contact dual-probe square resistance measurement device includes:

[0054] The first probe, the second probe, the main control unit, the display and the input and output unit.

[0055] The first probe, the second probe, and the display and input-output unit are all connected to the main control unit respectively.

[0056] The first probe is vertically arranged above the sample, and the second probe is vertically arranged below the sample. The centers of the first probe and the second probe are in a straight line, and neither the first probe nor the second probe contacts the sample.

[0057] In an embodiment of the present invention, the first probe and the second probe are cylindrical with a diameter of 20 mm. The first probe and the second probe are coaxially arranged in a direction perpendicular to the sample, so that the first probe and the second probe can be aligned with the same position on the upper and lower surfaces of the sample.

[0058] The first probe is provided with a first controller, a first excitation circuit, a first auxiliary circuit, a first shielding circuit, and a first AC power supply. The second probe is provided with a second controller, a second excitation circuit, a second auxiliary circuit, a second shielding circuit, and a second AC power supply.

[0059] The first auxiliary circuit and the second auxiliary circuit are both mutual inductance circuits.

[0060] The first shielding circuit and the second shielding circuit are used for electromagnetic field isolation.

[0061] The embodiment of the present invention has no special restrictions on the layout of the circuits in the probe.

[0062] like Figure 5 The figure shows a circuit structure diagram of the excitation circuit provided by some embodiments of the present invention. The first excitation circuit and the second excitation circuit can both adopt Figure 5 The circuit structure shown is shown. Specifically, the excitation circuit is an RLC parallel resonant circuit consisting of an AC power supply U1, a first capacitor C1, a first resistor R2, and a first inductor L1. U1 is a high-frequency AC current source, U2 is its equivalent DC voltage, and L2, R3 and L3, R4 are equivalent circuits of the wires, respectively. The shielding circuit is connected to the excitation circuit, specifically by connecting the shielding circuit in parallel to both ends of the first capacitor C1, forming a closed loop.

[0063] like Figure 6 The figure shows a schematic diagram of the circuit structure of the auxiliary circuit provided by some embodiments of the present invention. The first auxiliary circuit and the second auxiliary circuit can both adopt Figure 6 The circuit structure is shown. Figure 6 for Figure 5The mutual inductance circuit in the circuit shown is driven by the excitation circuit through mutual inductance. Its main components are the second capacitor C3 and the second inductor L4. R1 is a parasitic resistor, C2 is a parasitic capacitor, D1 is a diode, and C4 is a picofarad capacitor connected to ground to shield against high-frequency interference. The circuit parameters are typically set such that C3 = C1 and L4 = L1. The shielding circuit is connected to the auxiliary circuit, specifically by connecting the shielding circuit in parallel across the second capacitor C3, forming a closed loop.

[0064] In an embodiment of the present invention, the first shielding circuit and the second shielding circuit both include an energized shielding shell, a multi-point grounding circuit, and a filter circuit. When energized, the energized shielding shell can reflect and absorb external electromagnetic interference, such as conductive polymer materials (such as polyacetylene, polyaniline, etc.), oxide semiconductor materials (such as titanium dioxide, zinc oxide, etc.), and some composite materials (such as carbon nanotube / polymer composites, metal / insulator composites, etc.). The energized shielding shell can be powered by a first AC power supply or a second AC power supply, or by other external power supplies. The multi-point grounding technology is to set multiple grounding points on the energized shielding shell, and connect these grounding points together through low-impedance conductors (such as copper tape, metal braided mesh, etc.) to form a grounding plane. For example, 16 grounding points are evenly distributed in the cylindrical cavity of the probe, and these grounding points are connected with copper tape to ensure that the grounding impedance is as low as possible. Multiple filter circuits are set between the multiple grounding points and the energized shielding shell. The filter circuit uses a high-frequency feedthrough capacitor and inductor. An inductor with an inductance of several microhenries to several tens of microhenries is connected in series to the power line, and then a feedthrough capacitor with a capacity of several hundred to several thousand picofarads is connected in parallel.

[0065] In the embodiment of the present invention, the first controller and the second controller are switch circuits.

[0066] The display and input / output unit is used to set measurement parameters and display measurement results.

[0067] The main control unit receives the measurement parameters set by the display and input / output unit, controls the on / off of the circuits in the first probe and the second probe through the first controller and the second controller, measures the square resistance values ​​of the first film layer and the second film layer in turn, and calculates the square resistance values ​​of the first film layer and the second film layer based on the measurement results of the first probe and the second probe.

[0068] Under the control of the main control unit, the first controller controls the on / off connection between the first AC power supply and the first excitation circuit, the on / off connection between the first shielding circuit and the first excitation circuit, and the on / off connection between the first shielding circuit and the first auxiliary circuit. Connecting the first AC power supply to the first excitation circuit and the first shielding circuit to the first auxiliary circuit puts the first excitation circuit into operation, and the first auxiliary circuit and the first shielding circuit form a loop, thereby shielding the influence of the first auxiliary circuit on the first excitation circuit, which is equivalent to shutting down the first auxiliary circuit. Disconnecting the first AC power supply from the first excitation circuit and connecting the first shielding circuit to the first excitation circuit puts the first auxiliary circuit into operation, and the first excitation circuit and the first shielding circuit form a loop, thereby shielding the influence of the first excitation circuit on the first auxiliary circuit, which is equivalent to shutting down the first excitation circuit.

[0069] Under the control of the main control unit, the second controller controls the on / off connection between the second AC power supply and the second excitation circuit, the on / off connection between the second shielding circuit and the second excitation circuit, and the on / off connection between the second shielding circuit and the second auxiliary circuit. Connecting the second AC power supply to the second excitation circuit and the second shielding circuit to the second auxiliary circuit puts the second excitation circuit into operation and the second auxiliary circuit into shutdown. Disconnecting the second AC power supply from the second excitation circuit and connecting the second shielding circuit to the second excitation circuit puts the second auxiliary circuit into operation and the second excitation circuit into shutdown.

[0070] In an embodiment of the present invention, the non-contact dual-probe square resistance measuring device further includes a transmission and support device, which moves the sample to a detection range of the non-contact dual-probe square resistance measuring device.

[0071] like Figure 7 As shown, an embodiment of the present invention further provides a non-contact dual-probe square resistance measurement method, which is applied to the non-contact dual-probe square resistance measurement device as described above, and the method includes the following steps:

[0072] Step S1 , adjusting the oscillation frequency of the excitation circuit and the height of the probe so that the penetration depth of the probe covers a portion of the substrate and does not penetrate into the film layer opposite to the sample.

[0073] The probe in the embodiment of the present invention is a non-contact probe that uses the eddy current method to measure square resistance. The depth of eddy current detection, i.e., the penetration depth, is limited by physical properties. The penetration depth determines how deep below the material surface the eddy current method can detect. The embodiment of the present invention requires separate measurement of the square resistance of the first and second film layers to determine the thickness uniformity of the first and second film layers. Therefore, it is necessary to control the penetration depth so that the penetration depth covers part of the substrate and does not penetrate the film layer opposite the sample. Specifically, the penetration depth is adjusted by adjusting the oscillation frequency of the excitation circuit and the height of the probe based on the thickness of the substrate, the first and second film layers in the sample. When the square resistance of the first and second film layers measured by the measuring device are both within the allowable floating range of the nominal value and the results are stable, it indicates that the adjustment is in place. For ease of measurement, the oscillation frequency of the first excitation circuit is typically the same as the oscillation frequency of the second excitation circuit, and the vertical distance between the first probe and the sample is the same as the vertical distance between the second probe and the sample. The oscillation frequency of the first excitation circuit and the second excitation circuit is 1-100 MHz. In practical applications, the oscillation frequency is usually set to about 10 MHz.

[0074] Step S2: setting a switching frequency for measuring the square resistance values ​​of the first film layer and the second film layer and a detection frequency of the probe.

[0075] In actual applications, the user sets the switching frequency and the detection frequency through the display and input and output units. In an embodiment of the present invention, in step S2, the detection frequency of the first probe is the same as the detection frequency of the second probe, and the detection frequency is an integer multiple of the switching frequency. In actual applications, the switching frequency is usually set to 10Hz-50Hz, and the single-sided detection frequency is usually 1000Hz, that is, 1 detection per 1 millisecond (ms), and usually 10 or more detections are averaged. The above detection frequency and switching frequency can fully meet the production line beat.

[0076] Step S3 , controlling the on / off of the circuits in the first probe and the second probe according to the switching frequency, and measuring the square resistance of the first film layer and the second film layer in sequence.

[0077] In the embodiment of the present invention, the specific method of step S3 is:

[0078] When measuring the sheet resistance of the first film layer, the first controller is controlled to connect the first excitation circuit to the first AC power source and the first shielding circuit to the first auxiliary circuit. Simultaneously, the second controller is controlled to disconnect the second excitation circuit from the second AC power source and connect the second shielding circuit to the second excitation circuit. This circuit connection allows the first excitation circuit and the second auxiliary circuit to operate simultaneously, while the first auxiliary circuit and the second excitation circuit are turned off. The measured sheet resistance is the sheet resistance of the first film layer.

[0079] When measuring the square resistance of the second film layer, the first controller is controlled to disconnect the first excitation circuit from the first AC power supply and connect the first shielding circuit to the first excitation circuit. Simultaneously, the second controller is controlled to connect the second excitation circuit to the second AC power supply and connect the second shielding circuit to the second auxiliary circuit. This circuit connection allows the second excitation circuit and the first auxiliary circuit to operate simultaneously, while the first excitation circuit and the second auxiliary circuit are disabled. The square resistance of the second film layer is measured.

[0080] When measuring the square resistance values ​​of the first film layer and the second film layer, the measuring device obtains the measurement results according to the set detection frequency.

[0081] Step S4 , calculating the square resistance of the first film layer and the square resistance of the second film layer according to the square resistances measured by the first probe and the second probe and the square resistance of the substrate.

[0082] In the embodiment of the present invention, the specific method of step S4 is:

[0083] Assuming that the square resistance of the substrate is R0, when measuring the square resistance of the first film layer, the square resistance measured by the first probe is R1. If R0>R1, the square resistance of the first film layer RA=R1*R0 / (R0-R1); if R0<=R1, the square resistance of the first film layer RA=R1; when measuring the square resistance of the second film layer, the square resistance measured by the second probe is R2. If R0>R2, the square resistance of the second film layer RB=R2*R0 / (R0-R2); if R0<=R2, the square resistance of the second film layer RB=R2.

[0084] When measuring the first film layer, because the substrate is typically an insulator or a material with high resistivity, R0 is typically much greater than R1. If R0>R1, the first probe reading is equivalent to the parallel value of the sheet resistance of the first film layer and the substrate. Therefore, the sheet resistance of the first film layer is RA=R1*R0 / (R0-R1). If R0<=R1, the first probe reading is minimally affected by the substrate, and the R1 value can be directly used as the sheet resistance of the first film layer. The calculation principle for the sheet resistance of the second film layer is the same as that for the first film layer.

[0085] After the main control unit collects the measurement data from the first probe and the second probe, it calculates the square resistance values ​​of the first film layer and the second film layer according to the above method, and transmits the data to the display and input and output unit for output display, or for subsequent processing, including but not limited to detecting whether there are defects, drawing output images, and sending signals to the PLC (Programmable Logic Controller) to achieve automated control of the production process, such as automatically cutting defective areas or reprocessing, etc.

[0086] The non-contact dual-probe square resistance measurement device provided by the embodiment of the present invention has a square resistance detection range of 10mΩ / □ to 1000Ω / □.

[0087] The present invention has the following beneficial effects: A controller, an excitation circuit, an auxiliary circuit, a shielding circuit, and an AC power supply are provided in both the upper and lower probes. The controller is used to control the on / off switching between the excitation circuit and the AC power supply, the on / off switching between the auxiliary circuit and the shielding circuit, and the on / off switching between the excitation circuit and the shielding circuit. When the shielding circuit and the auxiliary circuit are connected, only the excitation circuit operates; when the shielding circuit and the excitation circuit are connected, only the auxiliary circuit operates. When measuring the square resistance of the film layer on the upper surface of a sample, the excitation circuit of the upper probe and the auxiliary circuit of the lower probe operate simultaneously; when measuring the square resistance of the film layer on the lower surface of a sample, the auxiliary circuit of the upper probe and the excitation circuit of the lower probe operate simultaneously. The on / off switching of the internal circuits of the upper and lower probes is controlled according to a set switching frequency, and the square resistance of the film layers on the upper and lower surfaces of the sample are measured sequentially. Using the solution of the present invention, the square resistance of the same position on the upper and lower surfaces of a sample can be simultaneously measured without additional movement or flipping of the sample and probes. This eliminates the need to purchase a new square resistance meter, nor does it require additional installation space or rotation and translation mechanisms. This saves costs, ensures detection accuracy, and improves detection efficiency.

[0088] The above is only a specific embodiment of the present invention and cannot be used to limit the scope of the present invention. Equal changes made by ordinary technicians in this technical field based on this creation, as well as changes well known to technicians in this field, should still fall within the scope of the present invention.

Claims

1. A non-contact dual-probe square resistance measurement device for simultaneously measuring the square resistance of the same position on the upper and lower surfaces of a moving sample on a production line, wherein the sample comprises a first film layer, a substrate, and a second film layer, wherein the first film layer and the second film layer are respectively located on the upper and lower surfaces of the substrate, characterized in that: The non-contact dual-probe square resistance measuring device comprises: A first probe, a second probe, a main control unit, a display and an input-output unit; The first probe, the second probe, and the display and input / output unit are respectively connected to the main control unit; The first probe is vertically arranged above the sample, and the second probe is vertically arranged below the sample. The centers of the first probe and the second probe are in a straight line, and neither the first probe nor the second probe contacts the sample. The first probe is provided with a first controller, a first excitation circuit, a first auxiliary circuit, a first shielding circuit, and a first AC power supply; the second probe is provided with a second controller, a second excitation circuit, a second auxiliary circuit, a second shielding circuit, and a second AC power supply; The first auxiliary circuit and the second auxiliary circuit are both mutual inductance circuits; The first shielding circuit and the second shielding circuit are used for electromagnetic field isolation; The display and input-output unit is used to set measurement parameters and display measurement results; The main control unit receives the measurement parameters set by the display and input / output unit, controls the on / off of the circuits in the first probe and the second probe through the first controller and the second controller, measures the square resistance values ​​of the first film layer and the second film layer in turn, and calculates the square resistance values ​​of the first film layer and the second film layer based on the measurement results of the first probe and the second probe.

2. The non-contact dual-probe square resistance measuring device according to claim 1, characterized in that: Under the control of the main control unit, the first controller controls the on / off connection between the first AC power supply and the first excitation circuit, the on / off connection between the first shielding circuit and the first excitation circuit, and the on / off connection between the first shielding circuit and the first auxiliary circuit; Under the control of the main control unit, the second controller controls the on-off connection between the second AC power supply and the second excitation circuit, the on-off connection between the second shielding circuit and the second excitation circuit, and the on-off connection between the second shielding circuit and the second auxiliary circuit.

3. The non-contact dual-probe square resistance measuring device according to claim 1, characterized in that: The first shielding circuit and the second shielding circuit both include a powered shielding shell, a multi-point grounding circuit and a filtering circuit.

4. The non-contact dual-probe square resistance measuring device according to claim 1, characterized in that: The non-contact dual-probe square resistance measuring device further includes a transmission and support device, which moves the sample to a detection range of the non-contact dual-probe square resistance measuring device.

5. A non-contact dual-probe square resistance measurement method, characterized in that: Applied to the non-contact dual-probe square resistance measurement device according to any one of claims 1 to 4, the method comprises the following steps: Step S1, adjusting the oscillation frequency of the excitation circuit and the height of the probe so that the penetration depth of the probe covers part of the substrate and does not penetrate the film layer opposite to the sample; Step S2, setting a switching frequency for measuring the square resistance values ​​of the first film layer and the second film layer and a detection frequency of the probe; Step S3, controlling the on / off of the circuits in the first probe and the second probe according to the switching frequency, and measuring the square resistance of the first film layer and the second film layer in sequence; Step S4 , calculating the square resistance of the first film layer and the square resistance of the second film layer according to the square resistances measured by the first probe and the second probe and the square resistance of the substrate.

6. The non-contact dual-probe square resistance measurement method according to claim 5, characterized in that: In step S1 , the oscillation frequency of the first excitation circuit is the same as the oscillation frequency of the second excitation circuit, and the vertical distance between the first probe and the sample is the same as the vertical distance between the second probe and the sample.

7. The non-contact dual-probe square resistance measuring device according to claim 6, characterized in that: The oscillation frequency of the first excitation circuit and the second excitation circuit is 1-100 MHz.

8. The non-contact dual-probe square resistance measurement method according to claim 5, characterized in that: In step S2, the detection frequency of the first probe is the same as the detection frequency of the second probe, and the detection frequency is an integer multiple of the switching frequency.

9. The non-contact dual-probe square resistance measurement method according to claim 5, characterized in that: The specific method of step S3 is: When measuring the square resistance of the first film layer, controlling the first controller to connect the first excitation circuit to the first AC power supply and the first shielding circuit to the first auxiliary circuit, and simultaneously controlling the second controller to disconnect the second excitation circuit from the second AC power supply and connect the second shielding circuit to the second excitation circuit; When measuring the square resistance value of the second film layer, the first controller is controlled to disconnect the first excitation circuit from the first AC power supply and connect the first shielding circuit to the first excitation circuit, and at the same time, the second controller is controlled to connect the second excitation circuit to the second AC power supply and connect the second shielding circuit to the second auxiliary circuit.

10. The non-contact dual-probe square resistance measurement method according to claim 5, characterized in that: The specific method of step S4 is: Assuming the square resistance of the substrate is R0, when measuring the square resistance of the first film layer, the square resistance measured by the first probe is R1. If R0>R1, the square resistance of the first film layer RA=R1*R0 / (R0-R1); if R0<=R1, the square resistance of the first film layer RA=R1; when measuring the square resistance of the second film layer, the square resistance measured by the second probe is R2. If R0>R2, the square resistance of the second film layer RB=R2*R0 / (R0-R2); if R0<=R2, the square resistance of the second film layer RB=R2.

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