Four-point probe automatic measuring mechanism

Abstract

The utility model relates to the technical field of measuring equipment, and discloses a four-point probe automatic measuring mechanism, which comprises a measuring mechanism main body, a digital multimeter and a control driver, a horizontal base is arranged below the measuring mechanism body, a guide rail supporting device is installed on the upper portion of the horizontal base and comprises a guide rail, a guide rail top plate and a guide rail bottom plate, a stepping motor is installed on the upper portion of the guide rail top plate, a motor shaft of the stepping motor is connected with a lead screw, and a sliding block is installed on the lead screw. A probe fixing part is installed on the front side of the sliding block, a four-point probe and a distance measuring sensor are installed at the lower end of the probe fixing part, and the distance measuring sensor transmits data to a control driver; the control driver is electrically connected with the stepping motor; and a probe connecting line of the four-point probe is connected to an input port of the digital multimeter. The device can be applied to a four-point probe experiment in a laboratory, the probe feeding distance can be accurately controlled, the experiment repeatability is improved, and the experiment efficiency and the experiment data accuracy are improved.

Description

Technical Field

[0001] This utility model relates to the field of measuring equipment technology, and more specifically, to a four-point probe automatic measuring mechanism. Background Technology

[0002] Currently, the four-point probe technique is the most widely used method in semiconductor metrology. In the field of semiconductor equipment, the resistance value measured by the four-point probe can determine the quality of the diffusion layer. In high resistivity measurements, the four-point probe method has advantages such as extended resistance, lower contact resistance, and lower current consumption, which makes its application more widespread and its application in precision measurement even more prominent.

[0003] In practical applications, we often manually control the probe height, visually observing the distance between the probe and the sample to ensure the probe roughly touches the sample and reads the voltage and current. However, manual control is inconvenient in practice. If the probe is too close to the sample, excessive adjustment may puncture it, causing damage and inaccurate measurements. Conversely, insufficient adjustment may result in failure to reach the sample, leading to low measurement efficiency and inaccurate data. Furthermore, since the adjustment range is rarely consistent for each measurement, repeated testing is difficult, resulting in larger errors in the experimental data.

[0004] Therefore, it is necessary to design a four-point probe automatic measurement mechanism to solve the above-mentioned technical problems. Utility Model Content

[0005] In view of this, the present invention proposes an automatic measurement mechanism for four-point probes. This mechanism can be applied to laboratory four-point probe experiments, accurately control the probe distance, increase experimental repeatability, and improve experimental efficiency and the accuracy of experimental data.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An automatic measurement mechanism with a four-point probe includes a main body, a digital multimeter, and a control driver. The main body has a horizontal base at its base, and a guide rail support device is mounted on the upper part of the base. The guide rail support device includes a vertically arranged guide rail, a top plate mounted on the upper part of the guide rail, and a bottom plate mounted on the lower part of the guide rail. The bottom plate is fixedly mounted on the horizontal base. A stepper motor is mounted on the top plate, and the motor shaft of the stepper motor passes through the top plate and is connected to a vertically arranged lead screw on the front side of the guide rail via a coupling. The lower end of the lead screw is rotatably connected to the bottom plate. A... A slider is provided for operation. The stepper motor controls the lead screw to rotate, causing the slider to move up and down. The slider is guided up and down by a guide rod mounted on the guide rail support device. A probe fixing part is installed on the front side of the slider. A four-point probe is installed at the middle of the lower end of the probe fixing part. A distance sensor is installed at the lower edge of the probe fixing part. The distance sensor transmits data to the control driver. The control driver is electrically connected to the stepper motor and transmits electrical signals to the stepper motor to control the stepper motor to rotate counterclockwise or clockwise. The probe connection wires of the four-point probes are connected to the input port of the digital multimeter.

[0008] Preferably, the probe fixing part includes a probe fixing block installed on the front side of the slider. The probe fixing block has a probe connecting line channel that runs vertically through it. A probe fixing plate is installed below the probe connecting line channel. The four-point probe is installed on the probe fixing plate, and the probe connecting lines of the four-point probe pass through the probe connecting line channel and are connected to the input port of the digital multimeter.

[0009] Preferably, the probe fixing plate has four vertical holes arranged side by side, the four-point probe consists of four probes, and each probe is fitted with a sleeve, which passes through the corresponding hole and is fixed to the hole wall; the bottom of the four-point probe is directly opposite the upper surface of the horizontal base.

[0010] Preferably, the ranging sensor is fixed to the bottom edge of the probe fixing block and is used to measure the distance between the probe fixing block and the horizontal base.

[0011] Preferably, a vertical sliding rod is provided on each of the left and right sides of the guide rail as a guide rod, and the top and bottom ends of the sliding rod are respectively fixed to the top plate and bottom plate of the guide rail; rollers are fixed on the left and right sides of the rear side of the slider with the lead screw as the axis of symmetry, and the rollers are tactilely connected to the corresponding sliding rod on the same side.

[0012] Preferably, two rollers are rotatably connected from top to bottom on one of the side slide rods; a slider side plate for limiting the left and right movement of the probe fixing block is also fixed to the left and right sides of the slider.

[0013] Preferably, the digital multimeter is a Keithley 2400 digital multimeter.

[0014] Preferably, the control driver includes a stepper motor driver and a control board electrically connected to the stepper motor driver and controlling the stepper motor to perform corresponding actions.

[0015] Preferably, the lower end of the lead screw is rotatably connected to the guide rail base plate via a bearing mounted on the guide rail base plate.

[0016] Preferably, the four-point probe automatic measurement mechanism further includes a power supply connected to the control driver for voltage transformation and power supply to the control driver.

[0017] Compared with the prior art, the present invention provides a four-point probe automatic measurement mechanism that controls a stepper motor through a control driver, which can meet the automatic downward and upward resetting of the four-point probe. It can also accurately control the needle insertion distance with the help of a distance sensor, move the probe to a suitable position, and control the position of the probe to be fixed each time. The four-point probe measurement method is used to measure the sample located on the horizontal base and display the resistance value on a digital multimeter.

[0018] This invention effectively improves the repeatability of four-point probe experiments, reduces experimental errors, and increases experimental efficiency and data accuracy. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a general structural diagram (without connecting lines) of a four-point probe automatic measurement mechanism according to this utility model.

[0021] Figure 2 This is a general structural diagram (with lines connected) of a four-point probe automatic measurement mechanism according to this utility model.

[0022] Figure 3 This is a schematic diagram showing the connection between the horizontal base and the guide rail support device in this utility model.

[0023] Figure 4This is a structural diagram of the guide rail support device in this utility model.

[0024] Figure 5 This is a structural diagram of the slider and roller in this utility model.

[0025] Figure 6 This is a schematic diagram of the slider movement and guidance structure in this utility model.

[0026] Figure 7 This is a structural diagram of the probe fixing part in this utility model.

[0027] Figure 8 This is a structural diagram of the ranging sensor in this utility model.

[0028] Figure 9 This is a schematic diagram showing the connection between the stepper motor and the lead screw in this utility model.

[0029] In the diagram: 1-Main body of the measuring mechanism, 2-Digital multimeter, 3-Control driver, 4-Power supply, 5-Horizontal base, 6-Guide rail, 7-Guide rail top plate, 8-Guide rail bottom plate, 9-Stepper motor, 10-Coupling, 11-Lead screw, 12-Slider, 13-Distance sensor, 14-Probe connection cable, 15-Probe fixing block, 16-Probe fixing plate, 17-Probe, 18-Sleeve, 19-Side slide bar, 20-Roller, 21-Slider side plate, 22-Stepper motor driver, 23-Control board, 24-Bearing. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0031] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] Example:

[0034] See Figures 1 to 9 This embodiment provides a four-point probe automatic measurement mechanism, which mainly includes a measurement mechanism body 1, a digital multimeter 2, a control driver 3, and a power supply 4.

[0035] See Figure 3 , Figure 4 , Figure 9 Below the main body 1 of the measuring mechanism is a horizontal base 5, which serves as a support and a place for the sample to be tested. A guide rail support device is installed on the upper part of the horizontal base 5. The guide rail support device includes a vertically arranged guide rail 6, a guide rail top plate 7 installed on the upper part of the guide rail 6, and a guide rail bottom plate 8 installed on the lower part of the guide rail 6. The guide rail bottom plate 8 is fixedly mounted on the horizontal base 5. A stepper motor 9 is installed on the upper part of the guide rail top plate 7. The motor shaft of the stepper motor 9 passes through the guide rail top plate 7 and is connected to a lead screw 11 vertically arranged on the front side of the guide rail via a coupling 10. The lower end of the lead screw 11 is rotatably connected to the guide rail bottom plate 8 via a bearing 24 installed on the guide rail bottom plate 8. A slider 12 that cooperates with the lead screw 11 is installed on the lead screw 11. The stepper motor 9 controls the rotation of the lead screw 11 to drive the slider 12 to move up and down, and the slider 12 is guided up and down by a guide rod installed on the guide rail support device.

[0036] A probe fixing part is installed on the front side of the slider 12. A four-point probe is installed at the middle of the lower end of the probe fixing part. A distance sensor 13 is installed at the lower edge of the probe fixing part. The distance sensor 13 transmits data to the control driver 3. The control driver 3 is electrically connected to the stepper motor 9 and transmits electrical signals to the stepper motor 9 to control the stepper motor 9 to rotate counterclockwise or clockwise. The probe connection line 14 of the four-point probe is connected to the input port of the digital multimeter 2.

[0037] Power supply 4 is connected to control driver 3 to transform voltage and supply power to control driver 3. Specifically, power supply 4 converts 220V voltage to 24V to supply power to the driver.

[0038] In this embodiment, the guide rail base plate 8 is mounted and fixed on the horizontal base 5. This ensures the stability of the probe fixing part, the four-point probe, and the distance sensor 13 on the slider 12 when the stepper motor 9 rotates and drives the slider 12 to move up and down, thus eliminating vibration.

[0039] In a further specific embodiment, see [link to relevant documentation]. Figure 2 , Figure 7 , Figure 8 The probe fixing part includes a probe fixing block 15 installed on the front side of the slider 12. The probe fixing block 15 has a probe connecting wire channel that runs vertically through it. A probe fixing plate 16 is installed below the probe connecting wire channel. The four-point probe is installed on the probe fixing plate 16. At the same time, the probe connecting wire 14 of the four-point probe passes through the probe connecting wire channel and is connected to the input port of the digital multimeter 2.

[0040] Furthermore, four vertical holes are arranged side by side on the probe fixing plate 16. The four-point probe consists of four probes 17. A sleeve 18 is fitted over each probe 17. The sleeve 18 passes through the corresponding hole and is fixed to the hole wall to fix the position of the probe 17. The bottom of the four-point probe is directly opposite the upper surface of the horizontal base 5.

[0041] Therefore, this measuring device can use the four-point probe measurement method to measure the sample located on the horizontal base 5 and display the resistance value on the digital multimeter 2.

[0042] In this embodiment, the ranging sensor 13 is fixed to the bottom edge of the probe fixing block 15 and is used to measure the distance between the probe fixing block 15 and the horizontal base 5. For example, during the downward movement of the four-point probe, when the data read by the ranging sensor 13 is stable and equal to the sum of the thickness of the probe fixing plate and the length of the probe, the stepper motor 9 will be controlled to stop rotating, and the slider 12 and the corresponding probe resistance measuring device will stop moving.

[0043] More specifically, in this embodiment, the ranging sensor 13 is a TOF10120 sensor. The TOF10120 sensor has a communication baud rate of 9600 and uses I / O. 2 C serial communication.

[0044] See Figure 1 , Figure 5 , Figure 6 Each of the left and right sides of the guide rail 6 is provided with a vertical side slide rod 19 as a guide rod. The top and bottom ends of the side slide rod 19 are respectively fixed to the top plate 7 and the bottom plate 8 of the corresponding guide rail. The rear side of the slider 12 is fixed with rollers 20 on the left and right sides with the lead screw 11 as the axis of symmetry. The rollers 20 are tumbling connected to the side slide rods 19 on the same side.

[0045] In this embodiment, two rollers 20 are rolled from top to bottom on a side slide rod 19; a slider side plate 21 for limiting the left and right positions of the probe fixing block 15 is also fixedly connected to the left and right sides of the slider 12.

[0046] In this embodiment, the roller 20 is installed on the side and rear of the slider 12. When the slider 12 moves up and down under the drive of the lead screw 11, the roller 20 moves on the side slide rod 19, which effectively improves the motion efficiency of the slider 12 and reduces the error caused by resistance.

[0047] Furthermore, in this embodiment, by setting the slider 12 to move up and down along the lead screw 11, and the rollers 20 on both sides to move up and down along the side slide rod 19, the distance the probe moves is proportional to the number of steps the stepper motor rotates. Moreover, due to the use of the lead screw and slider structure, the slider 12 has a self-locking function, which can ensure that the slider 12 is stationary when the lead screw 11 is not rotating, thereby meeting the requirement of stable up and down movement of the slider.

[0048] In this embodiment, the digital multimeter 2 is a Keithley 2400 digital multimeter suitable for high-precision voltage and current measurements.

[0049] Meanwhile, the control driver 3 includes a stepper motor driver 22 and a control board 23 that is electrically connected to the stepper motor driver 22 and controls the stepper motor 9 to perform corresponding actions.

[0050] Stepper motor 9 is a 4-2 stepper motor, stepper motor driver 22 is a DM542DSP driver, and control board 23 is an Arduino UNO r3 development board.

[0051] In actual operation, the 4-2 stepper motor is connected to the DM542DSP driver via DuPont wires. The DM542DSP driver's output connectors use a common anode connection, active low. Connect the positive terminals of the pulse control, direction signal, and enable signal together, and then connect them to the 5V port of the Arduino UNO r3 development board. The DM542DSP driver's speed selection is set to 400 RPM. Since the stepper motor's rated current is 1.7A, the DM542DSP driver's adjustment setting is set to 1.46A. When the DM542DSP driver's wiring connections are correct, the indicator light on the DM542DSP driver will illuminate green.

[0052] Furthermore, this embodiment uses the Arduino UNO r3 development board to design three operating modes: Operating Mode 1: Fixed value increase mode; Operating Mode 2: Automatic decrease mode; Operating Mode 3: Fixed value decrease mode.

[0053] When the chip starts working, the serial debugger will display "Start," followed by a pop-up message: "Select operating mode: 1. Manual Upward 2. Automatic Downward 3. Manual Downward." After the user makes a selection, the Arduino UNO r3 development board will read the user's choice and display the corresponding prompt. This selection command satisfies four-probe position reset, automatic probe downward movement, and fine-tuning after probe downward movement. After completing the selected operating mode task in the four-point probe module, you can return to the operating mode selection area and wait for the next command control.

[0054] More specifically, the Arduino UNOr3 is connected to the input connector of the DM542DSP driver. When the Arduino UNOr3 reads the external input command, when operating mode 1 is selected, the stepper motor is driven to rotate counterclockwise, and the slider moves upward under the drive of the rotating lead screw. The corresponding resistance measuring mechanism mounted on the slider also moves upward. When operating mode 2 or 3 is selected, the stepper motor is driven to rotate clockwise, and the slider moves downward under the drive of the rotating lead screw. The corresponding resistance measuring mechanism mounted on the slider also moves downward.

[0055] The above-described design of the computer program in the Arduino UNO r3 development board belongs to the prior art. The Arduino UNO r3 development board is programmed to act as the control center of the stepper motor control system. Its main function is to control other modules in the design, receive data from the TOF10120 sensor, perform calculations, and send electrical signals to the stepper motor to control its rotation. For example: by controlling the stepper motor with Arduino, the number of motor rotation steps is input on the serial port debugging page, and the four-point probe measurement module (slider + probe fixing part + four-point probe + distance sensor) moves down; by controlling the stepper motor with Arduino, the number of motor rotation steps is input on the serial port debugging page, and the four-point probe measurement module moves up; by controlling the stepper motor with Arduino, the four-point probe measurement module moves down to the surface of the sample to be tested and measures the resistance.

[0056] This utility model discloses an automatic measurement mechanism for four-point probes. By controlling a stepper motor through a control driver, it can automatically move the four-point probes down and up and reset, and accurately control the probe distance. This allows the probes to be moved down to the appropriate position, improving the repeatability of four-point probe experiments, increasing experimental efficiency and the accuracy of experimental data.

[0057] Meanwhile, to ensure the probe is positioned correctly, this four-point probe automatic measurement mechanism is designed with three corresponding functions: probe return after measuring resistance, probe move upward and return after measuring resistance, and probe move downward for fine adjustment. This simplifies the complex operation of measuring resistance and realizes intelligent four-point probe measurement.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A four-point probe automatic measurement mechanism, characterized by, The utility model provides a kind of probe fixing part, which comprises a probe fixing block mounted on the front side of the slider, a probe connecting line channel is formed through up and down on the probe fixing block, a probe fixing plate is mounted below the probe connecting line channel, and four probes are mounted on the probe fixing plate, and the probe connecting line of the four probes passes through the probe connecting line channel and is connected to the input port of the digital multimeter.

2. The four-point probe automatic measurement mechanism according to claim 1, wherein, The probe fixing plate is provided with four vertical small holes side by side, the four probes are four probes, each probe is provided with a sleeve, the sleeve passes through the corresponding small hole and is fixed with the hole wall, and the lower side of the four probes is opposite to the upper surface of the horizontal base.

3. The four-point probe automatic measurement mechanism according to claim 2, wherein, The distance measuring sensor is fixed at the edge of the bottom surface of the probe fixing block, and is used for measuring the distance between the probe fixing block and the horizontal base.

4. The four-point probe automatic measurement mechanism according to claim 2, wherein, Each of the left and right sides of the guide rail is provided with a vertical side slide rod as a guide rod, the top end and the bottom end of the side slide rod are respectively fixed with the guide rail top plate and the guide rail bottom plate, the rear side of the slider is fixed with a roller on the left and right sides respectively with the screw as the axis of symmetry, and the roller is rollingly connected with the corresponding side slide rod on the same side.

5. The four-point probe automatic measurement mechanism according to claim 2, wherein, Two rollers are rollingly connected on one side slide rod from top to bottom; the left and right sides of the slider are further respectively fixed with a slider side plate for limiting the probe fixing block left and right.

6. The four-point probe automatic measurement mechanism according to claim 5, wherein, The digital multimeter is a GAOHSILI 2400 digital multimeter.

7. The four-point probe automatic measurement mechanism according to claim 1, wherein, The control driver includes a stepper motor driver and a control board electrically connected with the stepper motor driver and controlling the corresponding action of the stepper motor.

8. The four-point probe automatic measurement mechanism according to claim 1, wherein, The lower end of the screw is rotatably connected with the guide rail bottom plate through a bearing mounted on the guide rail bottom plate.

9. The four-point probe automatic measurement mechanism according to claim 1, wherein, ​ 10. The four-point probe automatic measurement mechanism according to any one of claims 1-9, wherein, A power supply is also included, which is connected to the control driver for voltage conversion and power supply to the control driver.

Images