High-precision silicon carbide crystal automatic measuring device

Abstract

The utility model provides a high-precision automatic measuring device for silicon carbide crystals, and relates to the technical field of semiconductor material detection. The single-chip microcomputer is fixedly arranged on the front surface of the fixed base, and a grating ruler terminal and a weighing instrument are sequentially and fixedly arranged on the side surface of the single-chip microcomputer from top to bottom; the X-axis driving mechanism is arranged above the fixed base, a laser range finder is fixedly arranged at the driving connection position of the X-axis driving mechanism and used for driving the laser range finder to move and adjust in the X-axis direction, grating ruler bodies are arranged on the X-axis driving mechanism and the Y-axis driving mechanism, a stepping motor lead screw transmission system is combined, closed-loop control is formed, and high-precision three-dimensional coordinate positioning is achieved; the problem that a traditional device is large in positioning error is solved, the laser range finder and the weighing sensor cooperate, multi-parameter synchronous measurement is achieved, the submicron order requirement is met, the full-automatic measurement process is combined with crystal positioning plate scale guiding, and manual intervention is reduced.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor material testing technology, and in particular to a high-precision automatic measuring device for silicon carbide crystals. Background Technology

[0002] The weight, size, and facet shape of silicon carbide crystals are important parameters characterizing the growth quality of crystals. Existing methods for measuring crystal bulk parameters require first placing the crystal on a thickness gauge platform to measure the thickness at a specified point to calculate the crystal's characteristic parameters; then transferring the crystal to an electronic balance to measure its weight; finally, the crystal's grade is determined based on its bulk parameters, and the growth process for the next batch is formulated accordingly.

[0003] This measurement process relies entirely on manual operation, which introduces significant systematic and human errors, affecting the accuracy of the results. Furthermore, the measurement process requires multiple transfers and rotations of the crystal, posing a risk of crystal damage.

[0004] Therefore, we propose a high-precision automatic measurement device for silicon carbide crystals. Utility Model Content

[0005] The purpose of this invention is to solve the problems in the existing technology where the measurement process relies on manual operation, which is prone to systematic and human errors, and the crystal is easily damaged by repeated transfer and rotation.

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

[0007] A high-precision silicon carbide crystal automatic measuring device includes a fixed base; a microcontroller, which is fixedly mounted on the front of the fixed base, and a grating ruler terminal and a weighing instrument are fixedly mounted on its side from top to bottom;

[0008] The X-axis drive mechanism is located above the fixed base, and a laser rangefinder is fixedly installed at its drive connection point to drive the laser rangefinder to move and adjust in the X-axis direction.

[0009] The Y-axis drive mechanism is fixedly installed on both sides of the top of the fixed base. It includes a drive part and a sliding support part. The drive part and the sliding support part are used to install the X-axis drive mechanism and drive the X-axis drive mechanism to move and adjust in the Y-axis direction.

[0010] The grating ruler body is located at the Y-axis drive mechanism and the X-axis drive mechanism, and is used to read the movement data of the Y-axis drive mechanism and the X-axis drive mechanism and transmit the data to the microcontroller in real time; the weighing sensor is located at the center of the top of the fixed base, and a crystal positioning plate is fixedly installed on the top. The crystal positioning plate is used to position the silicon crystal, and the weighing sensor is used to weigh the silicon crystal located at the crystal positioning plate. The data is displayed on the weighing instrument in real time, and the weight data is transmitted to the microcontroller in real time.

[0011] As a preferred embodiment of this utility model, the driving unit includes:

[0012] The first mounting base is fixedly installed on the left side of the top of the fixed base, and has a receiving cavity inside, with the opening of the receiving cavity facing upward;

[0013] The first lead screw is installed inside the receiving cavity of the first mounting base;

[0014] The first stepper motor is located on the front of the first mounting base, and its output end is connected to the first lead screw to drive the first lead screw to rotate.

[0015] The first slider is located at the first lead screw and is threadedly connected to the first lead screw, thereby realizing movement adjustment.

[0016] As a preferred embodiment of this utility model, the sliding support portion includes:

[0017] The second mounting base is fixedly installed on the right side of the top of the fixed base, and its structural shape is exactly the same as that of the first mounting base;

[0018] A linear optical axis is fixedly installed inside the second mounting base;

[0019] The second slider is disposed on the linear optical axis and is slidably connected to the linear optical axis to achieve movement adjustment.

[0020] As a preferred embodiment of this utility model, the X-axis drive mechanism includes:

[0021] A gantry frame, the bottom of which is fixedly connected to a first slider and a second slider respectively, has a placement cavity inside, and the opening of the placement cavity faces downward;

[0022] The second lead screw is installed inside the placement cavity of the gantry;

[0023] The third slider is located at the second lead screw and is threadedly connected to the second lead screw. Its bottom is fixedly connected to the laser rangefinder.

[0024] The second stepper motor is mounted on the right side wall of the gantry, and its output end is connected to the second lead screw, thereby driving the second lead screw to rotate.

[0025] As a preferred embodiment of this utility model, the crystal positioning plate is cylindrical in shape, with positive and negative scales in the X and Y axes on its top, and a positioning zero point is provided at the intersection of the scales in the two directions and at the center of the top of the crystal positioning plate.

[0026] When it is necessary to measure the silicon crystal, the silicon crystal is placed at the zero point of the crystal positioning plate. When the scales on the left and right sides of the edge of the silicon crystal are the same, and the scales on the top and bottom sides are the same, the silicon crystal is located in the center of the crystal positioning plate.

[0027] As a preferred embodiment of this utility model, the laser rangefinder can move to the positioning plate to locate the zero point according to the selected crystal size, and then move to the left to the position of crystal radius + 5mm to reset the position parameters to zero, and measure the height of the crystal at different positions, as well as the distance from the edge or center point, according to the pre-set path.

[0028] As a preferred embodiment of this utility model, the microcontroller further includes:

[0029] A display screen and operation buttons, wherein the display screen and operation buttons are used for human-computer interaction;

[0030] The data transmission module is used to transmit measurement data to a server or external storage device via WIFI or USB flash drive.

[0031] Compared with the prior art, the beneficial effects of this utility model are:

[0032] This invention achieves high-precision three-dimensional coordinate positioning by setting a grating ruler body on the X and Y axis drive mechanism and combining it with a stepper motor lead screw transmission system to form a closed-loop control, effectively solving the problem of large positioning errors in traditional equipment.

[0033] The laser rangefinder and the weighing sensor work together to achieve simultaneous measurement of multiple parameters, meeting the requirements for sub-micron level accuracy. The fully automated measurement process, combined with crystal positioning plate scale guidance, effectively reduces manual intervention and improves measurement efficiency. The integrated design effectively solves the drawbacks of dispersed functions. Attached Figure Description

[0034] Figure 1 A schematic diagram of the main structure of a high-precision silicon carbide crystal automatic measuring device provided by this utility model;

[0035] Figure 2 A schematic diagram of the main body structure of a high-precision silicon carbide crystal automatic measuring device provided by this utility model (from a bottom view).

[0036] Figure 3 A front-view schematic diagram of the main body of a high-precision silicon carbide crystal automatic measuring device provided by this utility model;

[0037] Figure 4 This is a schematic diagram of a high-precision silicon carbide crystal automatic measuring device provided by this utility model.

[0038] Legend: 10. Fixed base; 20. Y-axis drive mechanism; 201. First mounting base; 202. First lead screw; 203. First slider; 204. First stepper motor; 205. Second mounting base; 206. Linear optical axis; 207. Second slider; 30. X-axis drive mechanism; 301. Gantry; 302. Second lead screw; 303. Third slider; 304. Second stepper motor; 40. Grating ruler body; 50. Weighing sensor; 60. Crystal positioning plate; 70. Microcontroller; 80. Weighing instrument; 90. Laser rangefinder. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0040] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be provided below with reference to relevant embodiments, and several embodiments of this utility model will be given. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of this utility model more thorough and complete.

[0041] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] Example

[0044] like Figure 1-4 As shown, this utility model provides a high-precision silicon carbide crystal automatic measuring device, which uses a fixed base 10 as the core support and integrates a microcontroller 70, an X / Y axis drive mechanism, measuring sensor components (laser rangefinder 90, grating ruler, weighing sensor 50), and a human-machine interaction module. The fixed base 10 is used for the installation and support of the overall structure and is the stable foundation for the operation of the entire device.

[0045] By utilizing a collaborative mode of "mechanical transmission + sensor feedback + intelligent control", the XY axis movement of the measuring mechanism is realized by a stepper motor driving the lead screw. The grating ruler collects motion displacement data in real time to form a closed-loop control, ensuring positioning accuracy. The laser rangefinder 90 scans the crystal surface to obtain geometric parameters, and the weighing sensor 50 collects weight information simultaneously. Finally, the microcontroller 70 integrates and processes the data and presents it through the human-machine interaction module, realizing automated and high-precision measurement of multi-dimensional parameters of silicon carbide crystals.

[0046] The X-axis drive mechanism for precise X-axis scanning consists of a gantry 301, a second lead screw 302, a third slider 303, and a second stepper motor 304. The gantry 301 serves as a load-bearing frame, and through the threaded engagement between the second lead screw 302 and the third slider 303, the rotational motion of the motor is converted into the X-axis linear motion of the laser rangefinder 90.

[0047] The second stepper motor 304 receives the pulse signal from the microcontroller 70, drives the second lead screw 302 to rotate, and the third slider 303 moves along the lead screw axis, driving the laser rangefinder 90 to scan in the X-axis direction. By controlling the pulse frequency and number, the moving distance and speed are precisely adjusted, realizing the sub-micron level positioning of the laser rangefinder 90 in the X-axis, providing stable and accurate motion support for X-axis scanning of the crystal surface.

[0048] Y-axis drive mechanism - stable Y-axis movement

[0049] Drive unit (left side): The first mounting base 201 provides space for the lead screw installation. The first stepper motor 204 outputs power to drive the first lead screw 202 to rotate. The first slider 203 is threaded with the lead screw to convert the rotational motion into linear motion, which drives the X-axis drive mechanism to move along the Y-axis.

[0050] Sliding support (right side): The second mounting base 205 is symmetrical to the first mounting base 201. The linear optical axis 206 provides guidance for the second slider 207. The second slider 207 moves synchronously with the X-axis drive mechanism and cooperates with the left drive unit to ensure the horizontal stability of the X-axis drive mechanism when moving in the Y-axis, avoid tilting and jamming caused by unilateral drive, and improve the overall motion accuracy.

[0051] The left and right sides work together, with the left side stepper motor driving the active displacement and the right side linear optical axis 206-slider structure providing passive support and guidance, forming an "active + driven" Y-axis motion mode. With the help of the grating ruler to feed back displacement data, a closed-loop control of the Y-axis motion is constructed to ensure the high precision and high stability of the X-axis drive mechanism in the Y direction.

[0052] Measurement Sensing Components - Multi-parameter Acquisition

[0053] The grating ruler body 40 is installed on the X and Y axis drive mechanism. It reads the displacement data of the moving parts in real time and transmits it to the microcontroller 70. Based on the principle of grating diffraction, the grating ruler converts mechanical displacement into electrical signals. The microcontroller 70 calculates the precise position of the drive mechanism by analyzing the signals, providing a reference for the scanning path calibration and measurement point positioning of the laser rangefinder 90. It is the key to realizing high-precision closed-loop control of three-dimensional coordinates.

[0054] Laser rangefinder 90: Based on the laser time-of-flight (ToF) method, a laser pulse is emitted towards a silicon carbide crystal. By measuring the time difference between the emission and reception of the reflected light, the distance information of the measurement point on the crystal surface is calculated. Combined with the position data of the X and Y axis drive mechanism, the three-dimensional morphology of the crystal surface can be constructed, and geometric parameters such as diameter, thickness, and surface shape can be measured to meet the sub-micron level accuracy requirements.

[0055] Weighing sensor 50: Based on the strain gauge sensing principle, after the crystal is placed on the crystal positioning plate 60, the weight causes the sensor elastic body to undergo a slight deformation. The deformation causes the resistance of the strain gauge to change, which is converted into a voltage signal through a Wheatstone bridge. After being processed by the weighing instrument 80, the weight data is displayed and transmitted to the microcontroller 70, realizing the accurate acquisition of the crystal weight. In conjunction with the geometric parameter measurement, multi-dimensional detection is achieved.

[0056] Crystal Positioning Plate 60 - Precision Centering Auxiliary

[0057] Designed as a cylindrical structure with XY axis markings and a positioning zero point, the crystal is initially aligned using mechanical markings.

[0058] When the operator places the crystal, they observe the alignment of the crystal edge with the XY axis scale. When the absolute values ​​of the scales on the left and right sides and the top and bottom sides of the crystal edge are equal, the crystal center coincides with the positioning zero point. This mechanical alignment method provides a reference starting point for the automatic scanning of the laser rangefinder 90, reduces measurement errors caused by crystal placement deviations, and improves measurement repeatability and accuracy.

[0059] The microcontroller 70 serves as the core controller, receiving displacement signals from the grating ruler, distance signals from the laser rangefinder 90, and weight signals from the weighing sensor 50. Through built-in algorithms (such as coordinate calculation, data fitting, and error compensation), it processes and calculates parameters such as the geometric dimensions and surface features of the crystal. Simultaneously, it sends pulse commands to the stepper motor to control the movement of the drive mechanism, thereby automating the measurement process.

[0060] The display screen shows the measurement parameter setting interface, real-time measurement data, crystal 3D morphology map and other information; the operation buttons are used for interactive operations such as starting / pausing measurement and switching functions; the data transmission module supports WiFi wireless transmission (based on TCP / IP protocol, which can upload measurement data to the server) and physical export to USB flash drive (data is stored via USB communication protocol), which can meet the data management needs of different scenarios.

[0061] Workflow

[0062] Preparation stage

[0063] Place the silicon carbide crystal on the crystal positioning plate 60, observe through the XY axis scale, and adjust the crystal to center the positioning zero point (the left and right and the top and bottom scales are symmetrical).

[0064] Operators set measurement parameters (such as crystal size, scanning path, and sampling density) through the display screen and operation buttons of the microcontroller 70.

[0065] Motion and Measurement Phase

[0066] Y-axis motion: The first stepper motor 204 receives the instruction from the microcontroller 70 and drives the first lead screw 202 to rotate. The first slider 203 drives the X-axis drive mechanism to move along the Y-axis. The second slider 207 on the right slides synchronously along the linear optical axis 206. The grating ruler collects the Y-axis displacement data in real time and feeds it back to the microcontroller 70 to form a closed-loop control of Y-axis motion.

[0067] X-axis motion: The second stepper motor 304 receives the command and drives the second lead screw 302 to rotate, and the third slider 303 drives the laser rangefinder 90 to move along the X-axis; the grating ruler synchronously collects the X-axis displacement data to construct the X-axis motion closed-loop control.

[0068] Multi-parameter acquisition: The laser rangefinder 90 moves with the X and Y axis drive mechanism, scans the crystal surface along a preset path, and collects distance data at each measuring point; the weighing sensor 50 continuously collects crystal weight data and transmits it to the microcontroller 70.

[0069] Data processing and presentation stage

[0070] The microcontroller 70 integrates the XY axis displacement data of the grating ruler and the distance data of the laser rangefinder 90, and calculates the geometric parameters such as the diameter, thickness and surface flatness of the crystal through algorithms; combined with the weight data of the weighing sensor 50, a complete measurement result is formed.

[0071] Measurement results are displayed on the screen in real time (such as numerical values ​​and 3D topographic maps), and can also be transmitted to the server via WiFi or exported via USB flash drive for data analysis and quality traceability.

[0072] End Phase

[0073] After the measurement is completed, the stepper motor drives the X and Y axis drive mechanisms to reset, waiting for the next measurement task; the operator can choose to save, export the data or reset the parameters to start a new measurement.

[0074] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision silicon carbide crystal automatic measuring device, characterized in that, include: Fixed base (10); A microcontroller (70) is fixedly installed on the front of the fixed base (10), and a grating ruler terminal and a weighing instrument (80) are fixedly installed on its side from top to bottom. The X-axis drive mechanism (30) is set above the fixed base (10), and a laser rangefinder (90) is fixedly set at its drive connection point to drive the laser rangefinder (90) to move and adjust in the X-axis direction. The Y-axis drive mechanism (20) is fixedly installed on both sides of the top of the fixed base (10). It includes a drive part and a sliding support part. The drive part and the sliding support part are used to install the X-axis drive mechanism (30) and drive the X-axis drive mechanism (30) to move and adjust in the Y-axis direction. The grating ruler body (40) is set at the Y-axis drive mechanism (20) and the X-axis drive mechanism (30) to read the movement data of the Y-axis drive mechanism (20) and the X-axis drive mechanism (30) and transmit the data to the microcontroller (70) in real time. A weighing sensor (50) is located at the center of the top of the fixed base (10), and a crystal positioning plate (60) is fixedly installed on the top. The crystal positioning plate (60) is used to position the silicon crystal. The weighing sensor (50) is used to weigh the silicon crystal located at the crystal positioning plate (60). The data is displayed on the weighing instrument (80) in real time and the weight data is transmitted to the microcontroller (70) in real time.

2. The high-precision silicon carbide crystal automatic measuring device according to claim 1, characterized in that, The drive unit includes: The first mounting base (201) is fixedly disposed on the left side of the top of the fixed base (10), and has a receiving cavity inside, with the opening of the receiving cavity facing upward; The first lead screw (202) is installed inside the receiving cavity of the first mounting base (201); The first stepper motor (204) is located on the front of the first mounting base (201), and its output end is connected to the first lead screw (202) to drive the first lead screw (202) to rotate. The first slider (203) is located at the first lead screw (202) and is threadedly connected to the first lead screw (202) to achieve movement adjustment.

3. The high-precision silicon carbide crystal automatic measuring device according to claim 2, characterized in that, The sliding support portion includes: The second mounting base (205) is fixedly disposed on the right side of the top of the fixed base (10), and its structural shape is exactly the same as that of the first mounting base (201); A linear optical axis (206) is fixedly disposed inside the second mounting base (205); The second slider (207) is disposed on the linear optical axis (206) and is slidably connected to the linear optical axis (206) to achieve movement adjustment.

4. The high-precision silicon carbide crystal automatic measuring device according to claim 3, characterized in that, The X-axis drive mechanism (30) includes: A gantry (301) is fixedly connected at its bottom to a first slider (203) and a second slider (207) respectively, and has a placement cavity inside, with the opening of the placement cavity facing downwards; The second lead screw (302) is disposed in the placement cavity of the gantry (301); The third slider (303) is located at the second lead screw (302) and is threadedly connected to the second lead screw (302). Its bottom is fixedly connected to the laser rangefinder (90). The second stepper motor (304) is installed on the right side wall of the gantry (301), and its output end is connected to the second lead screw (302), thereby driving the second lead screw (302) to rotate.

5. The high-precision silicon carbide crystal automatic measuring device according to claim 4, characterized in that, The crystal positioning plate (60) is cylindrical in shape, with positive and negative scales in the XY axis on its top. At the junction of the scales in the two directions, a positioning zero point is provided at the center of the top of the crystal positioning plate (60). When it is necessary to measure the silicon crystal, the silicon crystal is placed at the zero point of the crystal positioning plate (60). When the scales on the left and right sides of the edge of the silicon crystal are the same, and the scales on the top and bottom sides are the same, the silicon crystal is located in the center of the crystal positioning plate (60).

6. The high-precision silicon carbide crystal automatic measuring device according to claim 5, characterized in that, The laser rangefinder (90) can move to the positioning plate to locate the zero point according to the selected crystal size, and then move to the left to the position of crystal radius + 5mm to reset the position parameters to zero. It can also measure the height of the crystal at different positions and the distance from the edge or center point according to the pre-set path.

7. The high-precision silicon carbide crystal automatic measuring device according to claim 6, characterized in that, The microcontroller (70) also includes: A display screen and operation buttons, wherein the display screen and operation buttons are used for human-computer interaction; The data transmission module is used to transmit measurement data to a server or external storage device via WIFI or USB flash drive.

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