Strain Gauge Chip Testing System and Testing Method

Abstract

This invention belongs to the field of strain gauge chip detection technology, specifically relating to a strain gauge chip detection system and method. The detection system includes a rotating module for carrying strain gauge wafers; an adsorption module mounted on a turntable for fixing the strain gauge wafers; a vision recognition module for identifying the positions of individual strain gauge chips on the adsorbed and fixed strain gauge wafers; a resistance measurement module including movable resistance probe components; and a control unit connected to the drive motor, vision recognition module, and resistance measurement module. By fixing the strain gauge wafers with the adsorption module, accurately locating the chips with the vision recognition module, and coordinating the resistance measurement module with the control unit for efficient measurement, this invention solves the problems of wafer displacement, detachment, and low detection efficiency in existing technologies. It effectively prevents strain gauge wafer displacement or detachment during the detection process, improves the accuracy and stability of vision recognition and resistance measurement, thereby enhancing detection efficiency and reliability.

Description

Technical Field

[0001] This invention belongs to the field of strain gauge chip testing technology, specifically relating to strain gauge chip testing systems and testing methods. Background Technology

[0002] Strain gauges, as core sensitive elements that convert mechanical strain into resistance changes, are widely used in the manufacture of force, pressure, and acceleration sensors. Their chips are usually mass-produced in wafer form. Before dicing and packaging, the hundreds to thousands of tiny strain gauge chips densely distributed on the wafer must undergo efficient and accurate electrical performance testing, especially resistance measurement, to screen out chips that do not meet the performance standards and ensure the reliability and consistency of the final sensor product.

[0003] However, existing inspection technologies face multiple challenges. Traditional devices generally use a single suction cup structure to adsorb strain gauge wafers. Due to design flaws in the airflow path, the negative pressure distribution is severely uneven, leading to frequent wafer displacement or accidental detachment during inspection. For example, when a wafer is placed on a rotating platform for process transfer, the centrifugal force generated by the rotation interacts with insufficient local negative pressure, easily causing chip position shift. At the same time, uneven adsorption force distribution can also cause local warping or overall slippage of the wafer surface. This not only interferes with the positioning accuracy of the vision recognition system and causes inaccurate acquisition of chip coordinate information, but also leads to unstable contact between the resistance probe and the chip during the resistance measurement stage, introducing measurement errors, and even damaging the chip surface or probe tip due to probe scratching. In addition, existing processes require wafers to be repeatedly moved and repositioned between vision inspection equipment, resistance measurement equipment, dicing equipment, and sorting equipment. This multi-step operation significantly extends the inspection cycle of a single wafer, reduces overall production efficiency, and significantly increases the risk of wafer breakage or contamination due to mechanical stress during handling. Summary of the Invention

[0004] The purpose of this application is to provide a strain gauge chip inspection system and inspection method that effectively prevents strain gauge wafers from shifting or falling off during the inspection process, improves the accuracy and stability of visual recognition and resistance measurement, and thus enhances inspection efficiency and reliability.

[0005] This application provides a strain gauge chip testing system, including: The rotating module includes a rotatable turntable and a drive motor for driving the turntable, which is used to carry strain gauge wafers. The adsorption module, installed on the turntable, is used to form a negative pressure adsorption zone on the upper surface of the turntable to fix the strain gauge wafer. A visual recognition module is used to identify the position of each strain gauge chip on the strain gauge wafer that has been adsorbed and fixed. Resistance measurement module, including a movable resistance probe assembly; The control unit is connected to the drive motor, vision recognition module, and resistance measurement module via signal transmission. The control unit is configured to control the resistance measurement module to perform resistance measurements on each strain gauge chip sequentially, based on the position information identified by the vision recognition module.

[0006] Furthermore, the drive motor is fixedly mounted on the frame, and the turntable has a central mounting hole at its center, through which the turntable is connected to the output shaft of the drive motor; The adsorption module includes a flange pipe, a vent plate, a vent connection plate, and a suction cup assembly; The flange pipe passes through the central mounting hole and is fixed to the turntable; The vent plate is fixed to the upper surface of the turntable and aligned with the flange pipe. The vent plate has multiple vents on its circumferential side. The suction cup assembly is located on the upper surface of the turntable and is connected to multiple air vents via air venting connection plates; The flange pipe, vent plate, vent connection plate, and suction cup assembly together form a negative pressure flow channel. The bottom end of the flange pipe is used to connect to the negative pressure generating device to generate negative pressure in the adsorption area of ​​the suction cup assembly.

[0007] Furthermore, the suction cup assembly includes a suction cup plate and a suction cup mesh plate. The suction cup plate has a ventilation groove that extends from its side to its top surface, and the top surface of the suction cup plate has a diversion groove that communicates with the ventilation groove. The diversion groove is located on both sides of the ventilation groove. The suction cup mesh plate is disposed on the top of the suction cup plate, and the suction cup mesh plate has mesh holes that correspond to the positions of the ventilation groove and the diversion groove, for forming a uniform negative pressure zone.

[0008] Furthermore, the diameter of the mesh in the suction cup perforated plate is 1-3mm, and the mesh spacing is 2-4mm.

[0009] Furthermore, the resistance measurement module also includes: The resistance measurement moving mechanism is fixedly mounted on the frame and is used to drive the resistance measurement probe assembly to move in three-dimensional space; The resistance measurement rotation mechanism is installed in the drive unit of the resistance measurement moving mechanism and is used to drive the resistance measurement probe assembly to rotate around an axis perpendicular to the turntable plane.

[0010] Furthermore, the resistance measuring moving mechanism includes a resistance measuring X-axis linear module, a resistance measuring Y-axis linear module, and a resistance measuring Z-axis linear module. There are two resistance measuring X-axis linear modules, which are respectively fixed to the frame by resistance measuring module brackets. The sliding part of the resistance Y-axis linear module is connected to the resistance X-axis linear module and spans between the two resistance X-axis linear modules; The sliding part of the resistance measurement Z-axis linear module is connected to the sliding part of the resistance measurement Y-axis linear module, and the resistance measurement rotation mechanism is installed on the sliding part of the resistance measurement Z-axis linear module; Among them, the resistance measurement X-axis linear module, the resistance measurement Y-axis linear module, and the resistance measurement Z-axis linear module are all equipped with photoelectric sensors to detect the sliding position of their corresponding sliding parts.

[0011] Furthermore, the resistance measuring rotation mechanism includes a hollow turntable, a turntable module motor that drives the hollow turntable, and a turntable mounting flange connected to the bottom of the hollow turntable; the resistance measuring probe assembly is installed below the turntable mounting flange; The visual recognition module includes an industrial camera and a camera light source. The industrial camera is fixedly mounted on the side of the turntable mounting flange via a camera bracket and moves synchronously with the resistance measuring rotation mechanism. The camera light source is fixedly mounted below the industrial camera via a light source mounting plate.

[0012] Furthermore, the resistance probe assembly includes several probe units and a resistance probe box for mounting the probe units. The probe unit includes at least four probes arranged in two parallel rows for electrical detection of multiple electrical contacts of the strain gauge chip. The hollow turntable, the turntable mounting flange, and the resistance probe box together form a wiring channel, and the cover plate of the resistance probe box has a wire insertion slot that communicates with the wiring channel.

[0013] Furthermore, the spacing between adjacent probes is 0.1-0.5 mm.

[0014] Furthermore, a detection method is provided for operating the above-mentioned strain gauge chip detection system, the detection method comprising: A strain gauge wafer is adsorbed and positioned using an adsorption module; The strain gauge wafer is transferred to the vision recognition module via a rotating module; The image of the strain gauge wafer is obtained by the visual recognition module, and the position coordinates of each strain gauge chip on it are identified. The control resistance measurement module drives the resistance measurement probe to move sequentially to each strain gauge chip for contact resistance measurement based on the position coordinates. The measured resistance results are associated with and stored with the corresponding strain gauge chip positions, and the strain gauge wafers are transferred to downstream equipment via a rotating module. Downstream equipment includes at least cutting and sorting equipment arranged around the turntable.

[0015] As can be seen from the above, the strain gauge chip detection system and detection method provided in this application fix the strain gauge wafer through an adsorption module, accurately locate the position of each chip through a vision recognition module, and coordinate the resistance measurement module through a control unit to perform efficient measurement. This solves the problems of wafer displacement, detachment and low detection efficiency in the prior art, effectively prevents the strain gauge wafer from displacing or detaching during the detection process, improves the accuracy and stability of vision recognition and resistance measurement, and thus enhances the advantages of detection efficiency and reliability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram showing the structure of the strain gauge chip detection system of the present invention; Figure 2 This is a schematic diagram showing the structure of the rotating module of the present invention; Figure 3 This diagram shows the structure of the adsorption module of the present invention. Figure 4 express Figure 3 A magnified schematic diagram of the partial structure at point A in the middle; Figure 5 This diagram shows the structure of the resistance measurement module of the present invention. Figure 6 A schematic diagram showing the structure of the resistance measuring moving mechanism of the present invention; Figure 7 This is a schematic diagram showing the structure of the resistance measuring rotary mechanism of the present invention; Figure 8 express Figure 7 A magnified schematic diagram of the structure at point B in the middle.

[0018] The reference numerals in the attached diagram are explained as follows: 1-Rotation module; 2-Adsorption module; 3-Vision recognition module; 4-Resistance measurement module; 11-Turntable; 12-Drive motor; 21-Flange pipe; 22-Ventilation plate; 23-Ventilation connection plate; 24-Suction cup assembly; 31-Industrial camera; 32-Camera light source; 41-Resistance probe assembly; 42-Resistance moving mechanism; 43-Resistance rotating mechanism; 241-Suction cup plate; 242-Suction cup perforated plate; 243-Ventilation slot; 244-Diverting air slot; 411-Probe unit; 412-Resistance probe box; 421-Resistance X-axis linear module; 422-Resistance Y-axis linear module; 423-Resistance Z-axis linear module; 431-Hollow turntable; 432-Turntable module motor; 433-Turntable mounting flange. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Traditional strain gauge chip electrical performance testing devices suffer from several problems when adsorbing strain gauge wafers. These problems include uneven airflow distribution from a single suction cup, which can lead to wafer displacement or detachment; insufficient local negative pressure can cause chip misalignment; and uneven adsorption force distribution can cause local warping or slippage of the wafer, affecting the accuracy of visual positioning and introducing errors when the probe contacts the wafer, or even scratching the chip or probe. At the same time, the wafer needs to be moved and positioned multiple times between different devices, resulting in long production cycles, low efficiency, and an increased risk of wafer breakage.

[0021] For ease of understanding, the following explains some key terms in this embodiment: The control unit is the core of the entire detection system. It is responsible for receiving and processing signals from various modules and sending control commands to each actuator according to a preset program or algorithm. In the detection system of this embodiment, the control unit coordinates the operation of the drive motor 12, the vision recognition module 3 and the resistance measurement module 4 to realize the automated detection process of the strain gauge chip.

[0022] A strain gauge wafer refers to a wafer in which multiple strain gauge chips are integrated onto a single circular silicon wafer during semiconductor manufacturing. During the testing process, the entire wafer is treated as a whole and subjected to adsorption and processing.

[0023] A strain gauge chip refers to a single strain gauge element cut from a strain gauge wafer. In this embodiment, the strain gauge element is a full-bridge strain gauge, meaning that a single strain gauge element contains four contact points to be tested, where the contact point is the smallest unit for electrical performance testing.

[0024] Please refer to Figures 1-8 This embodiment provides a strain gauge chip detection system, which comprises a rotation module 1, an adsorption module 2, a visual recognition module 3, a resistance measurement module 4, and a control unit.

[0025] The rotating module 1 is configured to carry the strain gauge wafer and enable its rotation. The rotating module 1 may include a rotatable turntable 11 and a drive motor 12 for driving the turntable 11. For example, the turntable 11 may be a circular platform connected to the drive motor 12 via belt drive or gear drive. The drive motor 12 may be a stepper motor or a servo motor to achieve the rotation of the turntable 11. In another implementation, the turntable 11 may be directly connected to the output shaft of the drive motor 12 via a bearing to achieve rotation.

[0026] The adsorption module 2 is installed on the turntable 11 to form a negative pressure adsorption area on the upper surface of the turntable 11 to fix the strain gauge wafer. The adsorption module 2 has multiple independent adsorption points, and each adsorption point is connected to a negative pressure source through a negative pressure channel to achieve uniform adsorption of the wafer.

[0027] The visual recognition module 3 is configured to identify the position of each strain gauge chip on the strain gauge wafer that is adsorbed and fixed; for example, the visual recognition module 3 may include a fixedly mounted camera that captures images when the wafer is stationary and identifies the chip positions through image processing software.

[0028] The resistance measurement module 4 includes a movable resistance probe assembly 41; for example, the resistance probe assembly 41 can be mounted on a four-dimensional moving platform and driven by a stepper motor or a DC motor to move in the XYZ three-dimensional space and achieve multi-angle rotation to position the probe assembly above the target chip; in another implementation, the resistance probe assembly 41 can be mounted on the end of a robotic arm and positioned in three-dimensional space by the joint movement of the robotic arm.

[0029] The control unit is connected to the drive motor 12, the vision recognition module 3, and the resistance measurement module 4 via signals. For example, the control unit can be an industrial PC that communicates with the controllers or drivers of each module via data cables, receives sensor signals, and sends control commands. In another implementation, the control unit can be an embedded controller that exchanges data and controls each module via a bus interface.

[0030] The control unit is configured to control the resistance measurement module 4 to sequentially measure the resistance of each strain gauge chip based on the position information identified by the vision recognition module 3. Specifically, the control unit receives the position coordinate data of the strain gauge chips provided by the vision recognition module 3, and then calculates the moving path and target position of the resistance measurement probe assembly 41 based on these coordinate data. Subsequently, the control unit sends a command to the resistance measurement module 4 to drive the resistance measurement probe assembly 41 to move above the row of strain gauge chips to perform contact resistance measurement. After the measurement is completed, the control unit drives the resistance measurement probe assembly 41 to move to the next row of strain gauge chips and repeats the measurement process until the resistance value of all target chips has been measured.

[0031] The strain gauge chip inspection system provided in this embodiment integrates a rotation module 1, an adsorption module 2, a vision recognition module 3, a resistance measurement module 4, and a control unit. This achieves stable bearing, adsorption, automated positioning, and resistance measurement of the strain gauge wafer. The system can prevent wafer displacement, warping, or detachment during the inspection process, improve the accuracy of visual positioning and the stability of probe contact, thereby reducing the risk of damage to the chip or probe. At the same time, through the unified coordination of the control unit, the system reduces the number of times the wafer is moved between different devices, thereby shortening the production cycle and improving inspection efficiency.

[0032] In some of the above embodiments, although it is proposed to fix the strain gauge wafer by adsorption module 2, in actual operation, how to ensure that the strain gauge wafer is stably and reliably adsorbed during high-speed rotation or precise positioning, and to achieve effective transmission and uniform distribution of negative pressure, is a technical problem that needs to be solved.

[0033] To address this, this embodiment further proposes a strain gauge chip detection system, wherein a drive motor 12 is fixedly mounted on a frame, and a central mounting hole is provided at the center of a turntable 11, which is connected to the output shaft of the drive motor 12 through the central mounting hole; the adsorption module 2 includes a flange tube 21, a vent plate 22, a vent connecting plate 23, and a suction cup assembly 24; the flange tube 21 passes through the central mounting hole and is fixed to the turntable 11; the vent plate 22 is fixed to the upper surface of the turntable 11 and is aligned with the flange tube 21, and the vent plate 22 has multiple vents on its circumferential side; the suction cup assembly 24 is disposed on the upper surface of the turntable 11 and is connected to multiple vents through the vent connecting plate 23; wherein the flange tube 21, the vent plate 22, the vent connecting plate 23, and the suction cup assembly 24 together form a negative pressure flow channel, and the bottom end of the flange tube 21 is used to connect to a negative pressure generating device to generate negative pressure in the adsorption area of ​​the suction cup assembly 24.

[0034] The adsorption module 2 is structurally designed to achieve efficient and uniform negative pressure adsorption. The flange tube 21, serving as the main channel for negative pressure transmission, is inserted into the central mounting hole of the turntable 11 and fixed to it. This design allows the flange tube 21 to rotate synchronously with the turntable 11 while maintaining connection to the external negative pressure generating equipment, ensuring a continuous supply of negative pressure. The vent plate 22 is fixed to the upper surface of the turntable 11 and precisely aligned with the flange tube 21. Multiple vents are provided on the circumferential sides of the vent plate 22, serving as intermediate links for the distribution of negative pressure from the center outwards. The suction cup assembly 24 is in direct contact with the strain gauge wafer. Part of it is set on the upper surface of the turntable 11 and is connected to multiple vents on the vent plate 22 through the vent connection plate 23; the function of the vent connection plate 23 is to guide the negative pressure from the vents of the vent plate 22 to the adsorption area of ​​the suction cup assembly 24; through the coordinated cooperation of the flange pipe 21, the vent plate 22, the vent connection plate 23 and the suction cup assembly 24, a complete negative pressure flow channel is constructed; the bottom end of the flange pipe 21 is designed to connect to the external negative pressure generating device. When the negative pressure generating device is started, the negative pressure is effectively transmitted to the adsorption area of ​​the suction cup assembly 24 through this flow channel, thereby generating a stable adsorption force on the strain gauge wafer.

[0035] The above technical solution ensures the continuity and stability of the negative pressure supply during the rotation of the turntable 11. Simultaneously, the multi-stage negative pressure distribution structure of the vent plate 22, vent connection plate 23, and suction cup assembly 24 ensures that the negative pressure is evenly distributed across the entire adsorption area of ​​the strain gauge wafer, avoiding problems of uneven local adsorption or insufficient adsorption force. This stable and uniform adsorption method greatly improves the positioning accuracy and stability of the strain gauge wafer during the detection process, providing a reliable foundation for the visual recognition module 3 to accurately identify the strain gauge chip position and for the resistance measurement module 4 to perform precise contact resistance measurement. This effectively solves the technical problem of unstable adsorption of the strain gauge wafer during high-speed rotation or precise positioning.

[0036] Furthermore, this embodiment further proposes that the suction cup assembly 24 includes a suction cup plate 241 and a suction cup mesh plate 242. The suction cup plate 241 is provided with a ventilation groove 243 that connects from its side to its top surface, and the top surface of the suction cup plate 241 is provided with a diversion groove 244 that communicates with the ventilation groove 243. The diversion groove 244 is located on both sides of the ventilation groove 243. The suction cup mesh plate 242 is disposed on the top of the suction cup plate 241, and the suction cup mesh plate 242 is provided with mesh holes corresponding to the positions of the ventilation groove 243 and the diversion groove 244, for forming a uniform negative pressure zone.

[0037] Specifically, the suction cup plate 241, as the main structure of the suction cup assembly 24, is responsible for bearing and initially distributing the negative pressure; the suction cup mesh plate 242 covers the suction cup plate 241, serving as the interface for contact with the strain gauge wafer, and its main function is to refine the negative pressure distribution and ensure the uniformity of adsorption; the ventilation groove 243 is the main channel for negative pressure to enter the suction cup plate 241 from inside the adsorption module 2 (through the ventilation connecting plate 23 and the ventilation port), and its structural design ensures that the negative pressure can be effectively introduced from the side and guided upward to the top surface of the suction cup plate 241; the diversion groove 244, based on the ventilation groove 243, further distributes the negative pressure on the top surface of the suction cup plate 241. The lateral diffusion and diversion of airflow, through the layout on both sides of the ventilation groove 243, can more effectively and evenly guide the negative pressure to various areas of the suction cup plate 241, providing a relatively uniform negative pressure source for the upper suction cup mesh plate 242. The suction cup mesh plate 242 is tightly attached to the top surface of the suction cup plate 241, and the mesh openings on it are precisely aligned with the ventilation groove 243 and the diversion groove 244 of the suction cup plate 241. These mesh openings are the interface where the negative pressure finally acts on the strain gauge wafer. Through the fine distribution of the mesh openings, the diverted air pressure inside the suction cup plate 241 can be further refined, thereby forming a highly uniform negative pressure adsorption area at the bottom of the strain gauge wafer.

[0038] Through the above technical solution, the negative pressure introduced by the flange pipe 21, the vent plate 22 and the vent connection plate 23 can be transformed from coarse regional adsorption to fine and uniform surface adsorption; effectively avoiding the problem of uneven negative pressure distribution that may be caused by traditional single adsorption structure, thereby ensuring that the strain gauge wafer can be stably, firmly and stress-free adsorbed and fixed; and ensuring that the resistance probe assembly 41 of the resistance measurement module 4 can be accurately aligned during contact measurement, avoiding measurement errors caused by wafer shaking or local deformation, and significantly improving the stability and measurement accuracy of the entire detection system.

[0039] This embodiment further proposes that the diameter of the suction cup perforated plate 242 is 1-3mm and the spacing between the perforations is 2-4mm.

[0040] Specifically, the mesh diameter on the suction cup perforated plate 242 is one of the key parameters affecting the negative pressure adsorption effect. If the mesh diameter is too small, the negative pressure transmission efficiency may be low, and the adsorption force may not be sufficient to stably fix the strain gauge wafer. If the mesh diameter is too large, a local high pressure difference may be formed at the mesh, resulting in uneven distribution of adsorption force, and may even cause deformation or damage to the strain gauge wafer during adsorption. Limiting the mesh diameter to the range of 1-3mm aims to achieve a good balance between adsorption force and adsorption uniformity, ensuring effective adsorption while avoiding unnecessary stress concentration on the wafer.

[0041] In this embodiment, by limiting the mesh diameter of the suction cup mesh plate 242 to 1-3mm and the mesh spacing to 2-4mm, the suction cup mesh plate 242 can form a more uniform and appropriate negative pressure adsorption area. This precise mesh design effectively avoids wafer damage caused by excessive adsorption force or wafer displacement caused by insufficient adsorption force.

[0042] This embodiment further proposes that the resistance measurement module 4 also includes a resistance measurement moving mechanism 42 and a resistance measurement rotating mechanism 43; wherein, the resistance measurement moving mechanism 42 is fixedly mounted on the frame and is used to drive the resistance measurement probe assembly 41 to move in three-dimensional space; the resistance measurement rotating mechanism 43 is mounted on the driving part of the resistance measurement moving mechanism 42 and is used to drive the resistance measurement probe assembly 41 to rotate around an axis perpendicular to the plane of the turntable 11.

[0043] The resistance measurement moving mechanism 42 is the core component for achieving precise spatial positioning of the resistance measurement probe assembly 41. Fixed to the frame, it ensures the stability and rigidity of the entire moving system, providing a solid foundation for subsequent precision movements. This mechanism can drive the resistance measurement probe assembly 41 to move in the three orthogonal directions of X, Y, and Z, enabling it to reach any position above the strain gauge chip on the strain gauge wafer. Specifically, the resistance measurement moving mechanism 42 can be composed of multiple linear motion modules. For example, two parallel X-axis linear modules can support a Y-axis linear module, and the Y-axis linear module can support a Z-axis linear module. A precision stepper motor or servo motor drives a ball screw or synchronous belt, working in conjunction with a high-precision guide rail to achieve smooth and controllable linear motion. Alternatively, it can adopt various forms such as a gantry structure or a cantilever structure to adapt to different spatial layouts and precision requirements.

[0044] The resistance measurement rotation mechanism 43 is designed to provide angular adjustment capability for the resistance measurement probe assembly 41. Mounted on the drive unit of the resistance measurement moving mechanism 42, it means that after the resistance measurement probe assembly 41 completes its three-dimensional spatial positioning, it can still be independently rotated and adjusted. This rotation capability allows the resistance measurement probe assembly 41 to be precisely aligned with the electrical contact end of the strain gauge chip, and even if the chip has a certain angular deviation on the wafer, it can be compensated for by rotation. This mechanism typically consists of a rotating platform or a hollow turntable 431, driven by a precision rotary motor (such as a stepper motor or servo motor) to achieve high-precision angular positioning. The rotation axis is perpendicular to the plane of the turntable 11, ensuring that the probe always maintains a perpendicular posture to the chip surface during rotation, which is beneficial for stable contact and accurate measurement.

[0045] This embodiment further proposes a specific implementation of the resistance measuring moving mechanism 42, which includes a resistance measuring X-axis linear module 421, a resistance measuring Y-axis linear module 422, and a resistance measuring Z-axis linear module 423. Specifically, two resistance measuring X-axis linear modules 421 are provided and are fixedly mounted on the frame by resistance measuring module brackets. These two resistance measuring X-axis linear modules 421 are arranged in parallel and are firmly installed on the system frame. The resistance measuring module brackets can be structural components made of high-strength aluminum alloy or steel. The linear modules are fixed to the frame by bolts or other means to ensure their stability and rigidity during movement. Using two parallel X-axis linear modules can provide a wider support base, enhance the stability and load-bearing capacity of the entire moving mechanism, and effectively reduce the shaking or deformation generated during Y-axis and Z-axis movement, thereby improving positioning accuracy and repeatability.

[0046] The sliding part of the resistance-measuring Y-axis linear module 422 is connected to the sliding part of the resistance-measuring X-axis linear module 421, and spans between the two resistance-measuring X-axis linear modules 421. The body of the resistance-measuring Y-axis linear module 422 or its slider is connected to the sliding part of each of the two resistance-measuring X-axis linear modules 421 through a connector (such as a connecting plate or connecting block). The Y-axis module spans across the two X-axis modules, forming a gantry-like structure. This connection method allows the Y-axis module to move as a whole along the X-axis direction, while the slider of the Y-axis module itself can move along the Y-axis direction, thereby realizing two-dimensional motion in the XY plane. The gantry structure can provide good rigidity and stability, reduce cantilever effect, and ensure smooth and accurate Y-axis motion.

[0047] The Z-axis linear module 423 for resistance measurement is connected to the sliding part of the Y-axis linear module 422 for resistance measurement, and the resistance rotation mechanism 43 is mounted on the sliding part of the Z-axis linear module 423 for resistance measurement. The body of the Z-axis linear module 423 for resistance measurement is connected to the sliding part of the Y-axis linear module 422 for resistance measurement via a connector. The resistance rotation mechanism 43 is mounted below or to the side of the sliding part of the Z-axis linear module 423 for resistance measurement, so that it can move up and down with the Z-axis module. The Z-axis module is responsible for providing vertical movement, so that the resistance probe assembly 41 can accurately descend and contact the strain gauge chip, or rise to avoid interference. The resistance rotation mechanism 43 is mounted on the sliding part of the Z-axis module, ensuring that the rotation mechanism can be height adjusted with the Z-axis, so as to perform rotation operation at different heights and adapt to wafers and probes of different thicknesses or installation heights.

[0048] In addition, the resistance measurement X-axis linear module 421, resistance measurement Y-axis linear module 422, and resistance measurement Z-axis linear module 423 are all equipped with photoelectric sensors to detect the sliding position of their corresponding sliding parts. The photoelectric sensor typically consists of a light emitter and a light receiver. The light emitter emits a light beam, and the light receiver receives the light beam. When the sliding part moves, the scale or obstruction on it will change the light path, thereby generating an electrical signal. After processing, these signals can accurately calculate the current position of the sliding part. The photoelectric sensor provides high-precision position feedback, enabling the control unit to obtain the precise position information of each axis in real time. This is crucial for achieving closed-loop control, as it can correct mechanical transmission errors, improve positioning accuracy and repeatability, and ensure that the resistance measurement probe assembly 41 can accurately position the electrical contact end of each strain gauge chip.

[0049] In some of the embodiments described above, the resistance measurement module 4 is configured to position the resistance measurement probe assembly 41 by means of the resistance measurement moving mechanism 42 and the resistance measurement rotating mechanism 43, so as to realize the resistance measurement of strain gauge chips at different positions and orientations. However, in actual operation, especially when performing precise measurement on tiny and densely arranged strain gauge chips, it is difficult to ensure that the resistance measurement probe assembly 41 can always be accurately aligned with the electrical contact end of the target chip by relying solely on the preset position information and the mechanical movement of the probe. If there is a lack of real-time visual feedback during the rotation of the probe, it may lead to alignment deviation, thereby affecting the accuracy and efficiency of the measurement results, and may even damage the probe or the chip.

[0050] To address this, this embodiment further proposes a strain gauge chip detection system, wherein the resistance measurement rotation mechanism 43 includes a hollow turntable 431, a turntable module motor 432 for driving the hollow turntable 431, and a turntable mounting flange 433 connected to the bottom of the hollow turntable 431; the resistance measurement probe assembly 41 is mounted below the turntable mounting flange 433; meanwhile, the visual recognition module 3 includes an industrial camera 31 and a camera light source 32, the industrial camera 31 is fixedly mounted on the side of the turntable mounting flange 433 by a camera bracket and moves synchronously with the resistance measurement rotation mechanism 43; the camera light source 32 is fixedly mounted below the industrial camera 31 by a light source mounting plate.

[0051] Specifically, the hollow turntable 431 in the resistance measuring rotation mechanism 43 is designed as a rotating component with an internal channel. Its main function is to provide space for the connecting cables or air passages of the resistance measuring probe assembly 41 to pass through, thereby avoiding entanglement or interference during probe rotation and ensuring the smoothness and stability of probe movement. The turntable module motor 432 that drives the hollow turntable 431 is usually a high-precision stepper motor or servo motor to achieve precise control of the angle of the hollow turntable 431, so that the resistance measuring probe assembly 41 can accurately rotate to the required measurement direction. The selection of the motor needs to consider its torque, accuracy, response speed, and compatibility with control. The compatibility of the control unit; the turntable mounting flange 433, which is connected to the bottom of the hollow turntable 431, serves as a stable mounting platform for the resistance probe assembly 41, ensuring that the probe assembly maintains a fixed relative position with the turntable 11 during rotation, thereby ensuring measurement accuracy; the flange design needs to ensure sufficient rigidity and connection accuracy to avoid vibration or displacement during rotation and measurement; the resistance probe assembly 41 is installed below the turntable mounting flange 433, allowing it to directly follow the resistance rotating mechanism 43 to rotate, achieving precise angular positioning of the probe, which is important for achieving precise angular positioning of the probe and subsequent contact measurement.

[0052] Furthermore, depending on different detection requirements, the camera light source 32 can be a ring light source, a coaxial light source, a strip light source, or a backlight source, etc.; the camera bracket and the light source mounting plate are used to securely mount the industrial camera 31 and the camera light source 32, respectively; the unique feature of this embodiment is that the industrial camera 31 is fixedly mounted on the side of the turntable mounting flange 433 by the camera bracket and is configured to move synchronously with the resistance measurement rotation mechanism 43; this means that when the resistance measurement probe assembly 41 rotates due to measurement requirements, the industrial camera 31 and the camera light source 32 below it will also rotate synchronously; the camera light source 32 is fixedly mounted below the industrial camera 31 by the light source mounting plate, ensuring that the light source and the camera form a close visual unit, and can provide the best lighting conditions for the industrial camera 31 no matter how the resistance measurement rotation mechanism 43 moves.

[0053] This embodiment further proposes a resistance measurement probe assembly 41 including a plurality of probe units 411 and a resistance measurement probe box 412 for mounting the probe units 411. The probe unit 411 includes at least four probes arranged in two parallel rows for electrical detection of multiple electrical contact terminals of the strain gauge chip. The hollow turntable 431, the turntable mounting flange 433 and the resistance measurement probe box 412 together form a wire passage. The cover plate of the resistance measurement probe box 412 is provided with a wire insertion slot communicating with the wire passage.

[0054] Specifically, the resistance probe assembly 41 is the core component of the resistance measurement module 4. Its main function is to establish a reliable electrical connection with the electrical contact terminals of the strain gauge chip to obtain a resistance signal. This assembly is typically composed of precision-machined conductive probes. The probe tips must have good conductivity and wear resistance to ensure the stability of the contact point with the chip and the accuracy of signal transmission. Several probe units 411 are modular components of the resistance probe assembly 41. Each unit contains a set of probes, and its design can be flexibly configured and replaced according to the electrode layout and detection requirements of different strain gauge chips, thereby improving the system's adaptability and maintenance convenience. The resistance probe box 412, used to mount the probe units 411, is a structural component whose function is to provide precise contact points for the probe units 411. The probe box provides mechanical support, positioning, and protection, ensuring a stable connection between the probe unit 411 and the resistance measurement rotation mechanism 43. It is typically made of insulating material to prevent electrical short circuits and features a precise internal positioning structure to ensure the positional accuracy of the probe unit 411 after installation. The probe unit 411 includes at least four probes arranged in two parallel rows. This probe configuration enables simultaneous detection of multiple electrical contacts on the full-bridge strain gauge chip, effectively eliminating the influence of lead resistance on the measurement results and significantly improving the accuracy of resistance measurement. The number and arrangement of the probes can be optimized based on the number and spacing of the electrodes on the strain gauge chip to ensure efficient and accurate electrical detection. Furthermore, the probe spacing can be precisely designed according to the chip electrode dimensions to ensure accurate contact.

[0055] To address cable management issues, this embodiment utilizes the structural features of the hollow turntable 431, the turntable mounting flange 433, and the resistance probe box 412 in the resistance measuring rotating mechanism 43, forming an internal cable routing channel. The hollow turntable 431 typically has a central hole, and the turntable mounting flange 433 also has internal space. By designing the resistance probe box 412 to connect with these components, a through, protected channel is formed. This cable routing channel provides a wiring path for the electrical connection cables of the resistance probe assembly 41, located near the axis of rotation and without interfering with external structures. Furthermore, the cover plate of the resistance probe box 412 has a cable insertion slot that communicates with the cable routing channel. This slot serves as an interface for cables to enter or leave the cable routing channel, facilitating cable introduction and exit, and ensuring smooth cable passage, further optimizing cable layout and management.

[0056] In actual operation, the electrical contact terminals of strain gauge chips are usually small in size and closely arranged. If the probe spacing of the probe unit 411 in the resistance measurement probe assembly 41 is not set properly, it may cause the probe to fail to accurately contact the target electrical contact terminal, or cause short circuits or damage to the chip when contacting, thereby affecting the accuracy and reliability of resistance measurement.

[0057] In this regard, this embodiment further proposes that the spacing between adjacent probes in the resistance probe assembly 41 is 0.1-0.5 mm.

[0058] The spacing between adjacent probes refers to the distance between the center lines of two adjacent probes within the same probe unit 411 in the resistance probe assembly 41. By limiting this spacing to the range of 0.1-0.5mm, it is ensured that the probes can accurately and stably contact the electrical contact terminals of the strain gauge chip, thereby forming a stable and reliable electrical connection between the probes and the electrical contact terminals, which significantly improves the accuracy and repeatability of resistance measurement.

[0059] In some of the embodiments described above, a strain gauge chip inspection system was proposed, which has the capabilities of adsorption, identification, and resistance measurement of strain gauge wafers. However, in its implementation, how to efficiently integrate these discrete inspection functions into a continuous and automated workflow, and ensure that the inspected wafers can be smoothly transferred to subsequent processing stages to improve overall production efficiency and data traceability, is a current technical challenge. To address this, this embodiment further proposes an inspection method that can be used in the above-mentioned strain gauge chip inspection system, specifically including the following steps: First, a strain gauge wafer is adsorbed and positioned by the adsorption module 2. The adsorption module 2 uses the principle of negative pressure to form a negative pressure adsorption area on the upper surface of the turntable 11, which firmly adsorbs and fixes the strain gauge wafer. The suction cup assembly 24 of the adsorption module 2 is connected to the negative pressure generating device through the negative pressure flow channel formed by the flange pipe 21, the vent plate 22, the vent connection plate 23 and the suction cup assembly 24, thereby generating a uniform negative pressure in the adsorption area of ​​the suction cup assembly 24, ensuring that the wafer is stable in position during the detection process, avoiding slippage or displacement, and providing an accurate reference for subsequent visual recognition and resistance measurement.

[0060] Subsequently, the strain gauge wafer is transferred to the vision recognition module 3 via the rotation module 1; the drive motor 12 in the rotation module 1 drives the rotatable turntable 11 to rotate, accurately transferring the adsorbed and fixed strain gauge wafer from the adsorption position to the working area of ​​the vision recognition module 3; the rotation of the turntable 11 is the key to realizing the automated flow of the wafer between different workstations, ensuring that the wafer can enter the field of view of the vision recognition module 3 according to the preset path, and preparing for image acquisition.

[0061] Next, the visual recognition module 3 acquires an image of the strain gauge wafer and identifies the position coordinates of each strain gauge chip on it. With the assistance of the camera light source 32, the industrial camera 31 in the visual recognition module 3 acquires images of the strain gauge wafer within its field of view, obtaining high-resolution wafer images. The control unit then uses image processing algorithms to analyze the acquired images, accurately identify the contours, center points, or key feature points of each strain gauge chip on the wafer, and calculates the precise position coordinates of each chip in the system coordinate system. This step is the basis for accurate alignment in subsequent resistance measurements.

[0062] Based on this, the control resistance measurement module 4 drives the resistance measurement probes to move sequentially to each strain gauge chip for contact resistance measurement according to the position coordinates. The control unit precisely controls the resistance measurement module 4 according to the position coordinate information of each strain gauge chip provided by the vision recognition module 3. Specifically, the control unit instructs the resistance measurement moving mechanism 42 to drive the resistance measurement probe assembly 41 to move in three-dimensional space, and simultaneously instructs the resistance measurement rotating mechanism 43 to drive the resistance measurement probe assembly 41 to rotate around an axis perpendicular to the plane of the turntable 11, so as to ensure that the probe unit 411 in the resistance measurement probe assembly 41 can accurately align with and contact the electrical contact end of the target strain gauge chip. The probe unit 411 typically contains at least four probes arranged in two parallel rows, which can simultaneously perform electrical detection on multiple electrical contact ends of the full-bridge strain gauge chip, thereby completing the resistance measurement.

[0063] Finally, the measured resistance results are associated with and stored in relation to the corresponding strain gauge chip positions, and the strain gauge wafers are transferred to downstream equipment via the rotation module 1. After the resistance measurement of each strain gauge chip is completed, the control unit associates the measured resistance value with the precise position coordinates of the chip and stores this data in the database to form a traceable inspection report. Subsequently, the rotation module 1 drives the turntable 11 to rotate again, transferring the inspected strain gauge wafers from the resistance measurement station to the downstream equipment. This step realizes the binding of inspection data with physical chips and provides an interface for subsequent automated processing. The downstream equipment includes at least a cutting device and a sorting device surrounding the turntable 11. The downstream equipment is designed to surround the turntable 11, forming a tightly integrated workstation with the turntable 11. The cutting device is used to precisely cut and separate the inspected and qualified strain gauge chips on the wafer, while the sorting device automatically classifies the strain gauge chips according to the previously stored resistance measurement results, such as separating qualified and unqualified products or classifying them according to performance indicators.

[0064] Through the above technical solution, this embodiment provides a highly efficient, automated, and integrated strain gauge chip inspection method. This method seamlessly connects multiple stages such as wafer adsorption and positioning, visual recognition, resistance measurement, and subsequent cutting and sorting, forming a continuous production process. Specifically, the precise adsorption of the adsorption module 2 and the automated transfer of the rotation module 1 ensure the stability and flow efficiency of the wafer during the inspection process. The precise position coordinates provided by the visual recognition module 3 provide accurate navigation for the resistance measurement probe of the resistance measurement module 4, ensuring the accuracy and automation of the measurement. More importantly, the measurement results are associated with the chip position and stored, and the wafer is directly transferred to the cutting and sorting equipment surrounding the turntable 11 using the rotation module 1, which greatly shortens the production cycle, reduces manual intervention and handling errors, and improves overall production efficiency and data traceability. This integrated design enables the inspection and subsequent processing of strain gauge chips to be completed efficiently on a unified platform, significantly improving the automation level of the production line and the product quality control capability.

[0065] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A strain gauge chip testing system, characterized in that, include: A rotating module includes a rotatable turntable and a drive motor for driving the turntable, the turntable being used to carry strain gauge wafers; An adsorption module, installed on the turntable, is used to form a negative pressure adsorption zone on the upper surface of the turntable to fix the strain gauge wafer. A visual recognition module is used to identify the position of each strain gauge chip on the strain gauge wafer that has been adsorbed and fixed. Resistance measurement module, including a movable resistance probe assembly; as well as The control unit is signal-connected to the drive motor, the vision recognition module, and the resistance measurement module. The control unit is configured to control the resistance measurement module to sequentially measure the resistance of each strain gauge chip based on the position information identified by the visual recognition module.

2. The strain gauge chip detection system as described in claim 1, characterized in that, The drive motor is fixedly mounted on the frame, and the turntable has a central mounting hole at its center. The turntable is connected to the output shaft of the drive motor through the central mounting hole. The adsorption module includes a flange pipe, a vent plate, a vent connection plate, and a suction cup assembly. The flange tube passes through the central mounting hole and is fixed to the turntable; The vent plate is fixed to the upper surface of the turntable and aligned with the flange pipe. The vent plate has multiple vents on its circumferential side. The suction cup assembly is disposed on the upper surface of the turntable and is connected to a plurality of the ventilation ports through the ventilation connection plate; The flange pipe, the vent plate, the vent connection plate, and the suction cup assembly together form a negative pressure flow channel. The bottom end of the flange pipe is used to connect to a negative pressure generating device to generate negative pressure in the adsorption area of ​​the suction cup assembly.

3. The strain gauge chip detection system as described in claim 2, characterized in that, The suction cup assembly includes a suction cup plate and a suction cup mesh plate. The suction cup plate has a ventilation groove that extends from its side to its top surface, and the top surface of the suction cup plate has a diversion groove that communicates with the ventilation groove. The diversion groove is located on both sides of the ventilation groove. The suction cup mesh plate is disposed on the top of the suction cup plate, and the suction cup mesh plate has mesh holes that correspond to the positions of the ventilation groove and the diversion groove, for forming a uniform negative pressure zone.

4. The strain gauge chip detection system as described in claim 3, characterized in that, The suction cup perforated plate has a mesh diameter of 1-3mm and a mesh spacing of 2-4mm.

5. The strain gauge chip detection system as described in claim 1, characterized in that, The resistance measurement module also includes: The resistance measurement moving mechanism is fixedly mounted on the frame and is used to drive the resistance measurement probe assembly to move in three-dimensional space; A resistance measuring rotation mechanism is installed on the drive unit of the resistance measuring moving mechanism and is used to drive the resistance measuring probe assembly to rotate around an axis perpendicular to the turntable plane.

6. The strain gauge chip detection system as described in claim 5, characterized in that, The resistance measuring moving mechanism includes a resistance measuring X-axis linear module, a resistance measuring Y-axis linear module, and a resistance measuring Z-axis linear module. There are two resistance measuring X-axis linear modules, which are respectively fixed to the frame by resistance measuring module brackets. The sliding part of the resistance Y-axis linear module is connected to the sliding part of the resistance X-axis linear module, and is disposed between the two resistance X-axis linear modules; The Z-axis linear resistance measurement module is connected to the sliding part of the Y-axis linear resistance measurement module, and the resistance measurement rotation mechanism is mounted on the sliding part of the Z-axis linear resistance measurement module. The X-axis linear module, Y-axis linear module, and Z-axis linear module are all equipped with photoelectric sensors to detect the sliding position of their respective sliding parts.

7. The strain gauge chip detection system as described in claim 5, characterized in that, The resistance measuring rotary mechanism includes a hollow turntable, a turntable module motor for driving the hollow turntable, and a turntable mounting flange connected to the bottom of the hollow turntable; the resistance measuring probe assembly is installed below the turntable mounting flange. The visual recognition module includes an industrial camera and a camera light source. The industrial camera is fixedly mounted on the side of the turntable mounting flange via a camera bracket and moves synchronously with the resistance measuring rotation mechanism. The camera light source is fixedly mounted below the industrial camera via a light source mounting plate.

8. The strain gauge chip detection system as described in claim 7, characterized in that, The resistance measurement probe assembly includes several probe units and a resistance measurement probe box for mounting the probe units. The probe unit includes at least four probes arranged in two parallel rows for electrical detection of multiple electrical contact terminals of the strain gauge chip. The hollow turntable, the turntable mounting flange, and the resistance probe box together form a wire threading channel, and the cover plate of the resistance probe box has a wire insertion slot that communicates with the wire threading channel.

9. The strain gauge chip detection system as described in claim 8, characterized in that, The spacing between adjacent probes is 0.1-0.5 mm.

10. A detection method, characterized in that, The strain gauge chip testing system as described in any one of claims 1-9, wherein the testing method comprises: A strain gauge wafer is adsorbed and positioned by the adsorption module; The strain gauge wafer is transferred to the visual recognition module via the rotating module; The visual recognition module acquires an image of the strain gauge wafer and identifies the position coordinates of each strain gauge chip on it. The resistance measurement module is controlled to drive the resistance probe to move sequentially to each strain gauge chip for contact resistance measurement according to the position coordinates. The measured resistance results are associated with and stored with the corresponding strain gauge chip positions, and the strain gauge wafers are transferred to downstream equipment via the rotating module. The downstream equipment includes at least a cutting device and a sorting device arranged around the turntable.

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