Wafer bump probe closed-loop force control system, method, terminal and storage medium

Abstract

The application discloses a wafer bump probe closed-loop force control system and method, an intelligent terminal and a storage medium, and belongs to the technical field of semiconductor wafer detection. The system comprises a Z-axis vertical movement execution module, a detection module and a control module, integrates pressure, position and speed detection units, and is matched with a multidimensional leveling mechanism. The application adopts a fast and slow staged feeding strategy, controls the probe to feed at a first speed first, switches to low-speed approach after contacting the wafer or reaching the preset position, realizes accurate shutdown by collecting contact pressure in real time and combining a preset pressure threshold interval, sets a stroke termination early warning and a speed checking mechanism, and matches a circumferentially arranged force sensor to guarantee pressure detection accuracy. The application solves the problems of inaccurate pressure control, wafer damage and low detection reliability of traditional probes, can accurately control the contact pressure of the probe, takes into account the detection efficiency and accuracy, and is suitable for different flatness wafer detection conditions.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging and testing technology, and in particular to a wafer bump probe closed-loop force control system, method, terminal and storage medium. Background Technology

[0002] With the rapid development of the advanced semiconductor packaging industry, the demand for flexible processing and inspection of fragile and delicate precision components such as wafers and IC chips is increasing. The force control performance and response time of servo systems have become core indicators for measuring processing and inspection performance. In wafer probe testing, the probe must precisely contact the metal pads or microbumps on the wafer surface; these contact targets are typically only tens of micrometers in size. Controlling the contact force directly determines the success or failure of the test: if the pressure is too high, the probe may scratch the chip surface or crack the pad structure; if the pressure is too low, it will lead to poor contact, distorting the test signal and affecting the accuracy of yield assessment.

[0003] Driven by Moore's Law, chip feature sizes continue to shrink and integration levels continue to increase. Especially in advanced 3D packaging and system-in-package, the density and number of microbumps are increasing dramatically, which places demands on probe devices far exceeding those of traditional solutions in terms of force control accuracy, response speed, and the uniformity of multi-point contact.

[0004] Currently, most existing probe force control devices employ open-loop or semi-closed-loop control methods based on position servo systems. These solutions typically rely on motor encoders or linear encoders to achieve positional closed-loop control, while contact force is indirectly guaranteed by setting a fixed downward stroke. However, in actual operating conditions, wafers themselves exhibit thickness variations and warping, probe tips gradually wear down, and pad heights are difficult to guarantee are absolutely consistent. Therefore, a fixed position stroke cannot guarantee that the contact force at every test point is within a safe and effective range. This can easily lead to some pads being damaged due to overpressure, or some pads experiencing poor contact due to insufficient contact force. Summary of the Invention

[0005] The technical problem to be solved by this invention is that, in existing wafer probe testing using open-loop or semi-closed-loop position control methods, the contact force is uncontrollable, which can easily damage the chip or cause poor connection due to factors such as wafer warping, thickness deviation, and probe wear. This application provides a wafer bump probe closed-loop force control device and control method that can achieve accurate, fast, and adaptive force control.

[0006] In a first aspect, this application provides a closed-loop force control system for wafer bump probes, which adopts the following technical solution: A closed-loop force control system for wafer bump probes, characterized in that it comprises: Z-axis vertical motion execution module, detection module, and control module; Both the Z-axis vertical motion execution module and the detection module are electrically connected to the control module. The control module is preset with a first speed value, a second speed value, and a first pressure threshold range; The Z-axis vertical motion execution module is configured to receive a first control signal from the control module and drive the probe head to move toward the wafer at a first speed value. The first control signal is a signal that controls the probe head to make an initial movement. The detection module includes a pressure detection unit, which is configured to generate a first feedback signal when the pressure value generated by the probe head contacting the wafer is detected for the first time, and send the first feedback signal to the control module. The control module is configured to generate a second control signal when a first feedback signal is received, and the Z-axis vertical motion execution module is configured to receive the second control signal and drive the probe head to move toward the wafer at a preset second speed value. The pressure detection unit is also configured to continuously detect the pressure value between the probe head and the wafer after the first feedback signal is generated; The control module is also configured to acquire the pressure value detected by the pressure detection unit in real time and determine whether the pressure value is within a preset first pressure threshold range. When the pressure value is within the first pressure threshold range, the control module sends a stop signal to the Z-axis vertical motion execution module. The Z-axis vertical motion execution module is configured to receive the stop signal and control the probe head to stop moving.

[0007] In one specific implementation, the control module has a preset first position, and the detection module further includes a position detection unit, which is configured to generate a second feedback signal when the probe head is detected to have moved to the first position, and send the second feedback signal to the control module. The control module is configured to determine whether a first feedback signal has been received when a second feedback signal is received; if no first feedback signal is received, the probe head is driven to move toward the wafer at a preset second speed value. The pressure detection unit is also configured to continuously detect the pressure value between the probe head and the wafer after the position detection unit generates the second feedback signal.

[0008] In one specific implementation scheme, the control module further includes a preset starting position; the position detection unit is also configured to detect the position of the probe head in real time. When the position of the probe head is the starting position, the position detection unit sends a third feedback signal to the control module. When the position of the probe head is the first position, the position detection unit sends a second feedback signal to the control module. The control module is configured to control the probe head to move at a first speed value when it receives the third feedback signal, and to control the probe head to move at a second speed value when it receives the second feedback signal.

[0009] In one specific implementation scheme, the control module further includes a preset termination position. The position detection unit is configured to send a fourth feedback signal to the control module when it detects that the probe head has moved to the termination position. The control module is configured to send a stop signal to the Z-axis vertical motion execution module after receiving the fourth feedback signal. The Z-axis vertical motion execution module is configured to receive the stop signal and control the probe head to stop moving. At the same time, the control module acquires the pressure value detected by the current pressure detection unit. If the pressure value detected by the current pressure detection unit is not within the first pressure threshold range, the control module issues a warning signal.

[0010] In one specific implementation, the system further includes a leveling mechanism. The Z-axis vertical motion execution module is a Z-axis vertical motion actuator. The leveling mechanism is connected between the Z-axis vertical motion actuator and the probe head, and is used to adjust the tilt angle of the probe head relative to the plane to be measured about the X-axis direction and / or about the Y-axis direction, as well as the moving distance along the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular.

[0011] In one specific implementation, the detection module further includes a speed detection unit configured to detect the movement speed of the probe head in real time and feed the detection result back to the control module. The control module is configured to determine whether the movement speed of the probe head has reached a preset second speed value based on the received detection result. When the movement speed of the probe head has not reached the second speed value, the control module sends a second control signal to the Z-axis vertical motion execution module. The Z-axis vertical motion execution module is configured to adjust the movement speed of the probe head according to the second control signal until the movement speed of the probe head reaches the second speed value.

[0012] In one specific implementation, the pressure detection unit includes at least one force sensor; when multiple force sensors are included, the multiple force sensors are mounted in the same plane and distributed circumferentially.

[0013] In one specific implementation, the leveling mechanism includes a fixed plate, a movable plate, an elastic reset element, a fine-tuning bolt, and an adjusting bolt. The fixed plate and the movable plate are connected by the elastic reset member, and multiple elastic reset members are provided along the circumference. The fine-tuning bolts are provided in a one-to-one correspondence with the elastic reset components; The adjusting bolt acts between the movable plate and the fixed plate.

[0014] Secondly, this application provides a closed-loop force control method for wafer bump probes, employing the following technical solution: A closed-loop force control method for wafer bump probes includes the following steps: S1. Obtain the preset first speed value, second speed value, first pressure threshold range, initial position, first position, and termination position; S2. Obtain the real-time position of the probe head. When the probe head is in the initial position, generate a first control signal to control the probe head to move from the initial position toward the wafer at a first speed value. S3. Obtain the preset speed adjustment judgment condition and the probe head's operating parameters. When the probe head's operating parameters meet the speed adjustment judgment condition, generate a second control signal to control the probe head to move toward the wafer at a second speed value. S4. Real-time acquisition of the pressure value between the probe head and the wafer, and determination of whether the pressure value is within the preset first pressure threshold range; When the pressure value is within the first pressure threshold range, the control probe head stops moving.

[0015] In one specific implementation, the operating parameters of the probe head are real-time pressure parameters, and the speed adjustment determination condition is that when the probe head first detects pressure value generated by contacting the wafer, a second control signal is generated.

[0016] In one specific implementation scheme, the operating parameters of the probe head are real-time position parameters, and the speed adjustment determination condition is that when the real-time position parameters of the probe head are at a first position, a second control signal is generated.

[0017] In one specific implementation, generating the second control signal to control the probe head to move toward the wafer at a second speed value further includes the following steps: S301. When the speed adjustment judgment condition is triggered, obtain the real-time moving speed value of the probe head and the preset speed adjustment time. S302. Determine whether the real-time moving speed value has reached the second speed value. When the real-time moving speed value reaches the second speed value within the preset speed adjustment time, stop acquiring the real-time speed value of the probe head and control the probe head to move at a constant speed. When the real-time moving speed value does not reach the second speed value within the preset speed adjustment time, adjust the moving speed of the probe head until it reaches the second speed value.

[0018] In a specific feasible implementation, the following steps are also included: S401. Obtain the real-time position of the probe head; S402. When the real-time position of the probe head reaches the termination position, the pressure value between the probe head and the wafer is obtained. If the current pressure value is not within the first pressure threshold range, an early warning signal is sent out.

[0019] Thirdly, this application provides a smart terminal, which adopts the following technical solution: A smart terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed by the processor, the computer program implements a closed-loop force control method for wafer bump probes as described above.

[0020] Fourthly, this application provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium includes a readable storage medium and a computer program stored on the readable storage medium and running thereon, the computer program being loaded and executed by a processor to implement a closed-loop force control method for wafer bump probes as described above.

[0021] The beneficial effects of this invention are: 1. Achieve high-precision adaptive force control, eliminating chip damage and test connection issues. This application uses real-time pressure detection as the core closed-loop feedback basis, no longer relying on fixed pressure stroke positioning. It can dynamically adjust the probe feed action according to the actual contact state of each test point. Regardless of wafer warping, thickness tolerance, or probe wear and uneven micro-bump height due to long-term use, the contact pressure can be stably controlled within a preset safety threshold range. This avoids problems such as pad cracking, chip surface scratches, and microstructure damage caused by overpressure, while also eliminating faults such as poor contact, test signal distortion, data misinterpretation, and missed tests caused by insufficient pressure, significantly improving the accuracy and reliability of wafer testing.

[0022] 2. Balancing testing efficiency and operational safety, this application is adapted to high-precision testing cycles. It employs a graded speed control logic, with the probe feeding rapidly at the first speed during the idle phase to shorten idle travel time and improve the overall testing cycle time. Upon approaching the wafer or triggering a contact signal, it automatically switches to a second speed for low-speed, precise feeding, preventing high-speed impacts that could damage precision micro-bumps and pads. Simultaneously, it incorporates a dual protection mechanism of position limit and pressure warning. The maximum downward pressure stroke is limited by the termination position; overtravel triggers automatic shutdown and anomaly warning, effectively avoiding equipment overtravel failures and wafer batch defects, making it suitable for high-density micro-bump testing scenarios such as 3D packaging and system-in-package.

[0023] 3. Improved uniformity of multi-point contact pressure to meet advanced packaging testing requirements. This application is equipped with an adaptive leveling mechanism that can precisely adjust the X and Y axis yaw angles and Z axis displacement accuracy of the probe tip relative to the wafer plane under test, correcting probe tip tilt deviation and ensuring uniform contact pressure during multi-point and multi-bump testing. Simultaneously, the circumferentially distributed force sensor layout can collect contact pressure data from all directions, improving pressure detection accuracy and coverage. Attached Figure Description

[0024] Figure 1 This is an isometric view of this embodiment; Figure 2 This is an exploded view of this embodiment; Figure 3 This is a structural block diagram of a wafer bump probe closed-loop force control system according to this embodiment; Figure 4 This is a flowchart of a closed-loop force control method for wafer bump probes in this embodiment.

[0025] Explanation of reference numerals in the attached diagram: 1. Servo motor; 2. Crossed ball guide rail; 3. Precision ball screw; 4. Grating ruler reading head; 5. Fine-tuning bolt; 6. Locking nut; 7. Force sensor; 8. Output end face of transmission unit; 9. Probe head; 10. Elastic reset component; 12. Fixed plate; 14. Movable plate; 13. Adjusting bolt; 20. Z-axis vertical motion execution module; 21. Detection module; 211. Pressure detection unit; 212. Position detection unit; 213. Speed ​​detection unit; 22. Control module; 23. Leveling mechanism. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Example

[0027] Reference Figure 1 , Figure 2 and Figure 3 This embodiment provides a wafer bump probe closed-loop force control system, including a detection module 21, a control module 22, and a leveling mechanism 23. The Z-axis vertical motion execution module 20, the detection module 21, and the leveling mechanism 23 are all electrically connected to the control module 22.

[0028] In this embodiment, the Z-axis vertical motion execution module 20 is a Z-axis vertical motion actuator, which includes a drive unit and a transmission unit. The drive unit is preferably a servo motor 1, and the transmission unit is preferably a precision ball screw 3 and a cross ball guide rail 2. The drive unit drives the probe head 9 to move up and down along the Z-axis direction through the transmission unit, which is perpendicular to the wafer surface.

[0029] The detection unit includes a pressure detection unit 211, a position detection unit 212, and a speed detection unit 213.

[0030] The pressure detection unit 211 is used to detect the axial contact force on the probe head 9 in real time. In this embodiment, the pressure detection unit 211 includes three capacitive force sensors 7, which are mounted in the same plane and evenly distributed circumferentially. Each sensor has a force resolution of 0.01N. The force sensors 7 convert the detected force signals into voltage signals, and the control module 22 obtains the real-time pressure detection results by receiving the voltage signals.

[0031] The position detection unit 212 and the speed detection unit 213 are used to detect the Z-axis position and movement speed of the probe head 9, respectively. In this embodiment, the position detection unit 212 and the speed detection unit 213 are integrated into a grating ruler reading head 4, which works in conjunction with the servo motor 1 to output position and speed signals in real time.

[0032] The leveling mechanism 23 is connected between the Z-axis vertical motion actuator and the probe head 9, and is fixedly installed on the drive panel of the transmission unit. It is used to adjust the tilt angle of the probe head 9 relative to the plane to be measured (i.e. the wafer surface). Example

[0033] Reference Figure 1 , Figure 2 and Figure 3 This embodiment, based on Embodiment 1, provides a detailed description of the control logic of the control system.

[0034] Specifically, the control module 22 is equipped with preset parameters, including speed parameters, position parameters, a first pressure threshold range, and a preset speed adjustment time.

[0035] The speed parameters include a first speed value and a second speed value, and the position parameters are the starting position, the first position, and the ending position.

[0036] The starting position is the probe head standby safety origin, and the device is reset to the docking position after initial setup and testing. The first position is the buffer position, and the speed of the probe head will be adjusted in the first position; The termination position is the test position; the probe head stops moving when it reaches the termination position. The first speed value is the no-load rapid feed speed, which is used for the rapid movement of the probe head towards the wafer; The second speed value is the low-speed approach speed, which is the fine feed speed after the probe approaches / contacts the wafer.

[0037] In this embodiment, the overall control is divided into 5 timing stages.

[0038] First timing phase (initial movement phase): The position detection unit 212 detects the position of the probe head in real time. The control module 22 acquires the probe head position detected by the position detection unit 212 in real time and determines whether the current position is the starting position. Specifically, if the probe head position is the starting position, the position detection unit 212 generates a third feedback signal and sends it to the control module 22. After receiving the third feedback signal, the control module 22 generates a first control signal and transmits it to the Z-axis vertical motion execution module 20. After receiving the first control signal, the Z-axis vertical motion execution module 20 drives the probe head to move towards the wafer at a first speed value.

[0039] Second timing phase (movement speed change phase): There are two trigger switching logics for the probe head's moving speed to change from the first speed value to the second speed value. The control module 22 monitors both the pressure trigger switching logic and the position trigger switching logic simultaneously. If either condition is met, the probe head's moving speed can be controlled to change from the first speed value to the second speed value.

[0040] The pressure-triggered switching logic specifically includes: The pressure detection unit 211 detects the axial pressure between the probe tip and the wafer in real time, and the control module 22 acquires the pressure value detected by the pressure detection unit 211 in real time. When the pressure suddenly changes from 0 to greater than 0, it is determined that the probe tip has contacted the wafer. That is, when the pressure value generated by the probe tip contacting the wafer is detected for the first time, the pressure detection unit 211 generates a first feedback signal and sends it to the control module 22. Upon receiving the first feedback signal, the control module 22 generates a second control signal and sends it to the Z-axis vertical motion execution module 20. Upon receiving the second control signal, the Z-axis vertical motion execution module 20 drives the probe tip to move towards the wafer at a second speed value.

[0041] The speed detection unit 213 detects the moving speed of the probe head in real time, and the control module 22 acquires the speed value detected by the speed detection unit 213 in real time. Based on the acquired speed value, the control module 22 determines whether the moving speed of the probe head has reached a preset second speed value. When the moving speed of the probe head has not reached the second speed value, the control module 22 sends a second control signal to the Z-axis vertical motion execution module 20. The Z-axis vertical motion execution module 20 adjusts the moving speed of the probe head according to the second control signal until the moving speed of the probe head reaches the second speed value.

[0042] In one specific implementation scheme, when the control module 22 receives the first feedback signal, it immediately activates the speed regulation sub-logic. The speed regulation sub-logic involves the control module 22 acquiring the real-time speed of the probe head and the preset speed regulation time, comparing the current actual speed with the second speed value, and if the speed value reaches the second speed value within the preset speed regulation time, the control module 22 controls the probe head to continue moving at a constant speed. If the speed value does not reach the second speed value within the preset speed regulation time, the control module 22 continuously outputs speed regulation commands to correct the motor output of the servo motor until the speed reaches the second speed value.

[0043] The location-triggered switching logic specifically includes: The control module 22 acquires the probe head position detected by the position detection unit 212 in real time. When the probe head position is detected to move to the first position, the position detection unit 212 sends a second feedback signal to the control module 22. When the control module 22 receives the second feedback signal, it controls the probe head to move at a second speed value.

[0044] In a specific implementation scheme, the grating ruler reader 4 reads the Z-axis coordinate of the probe head in real time. When the probe head moves to the first position, the grating ruler reader 4 outputs a second feedback signal. After receiving the second feedback signal, the control module 22 performs an interlock judgment: querying whether the control module 22 has received the first feedback signal, that is, judging whether the probe head has contacted the wafer.

[0045] Case 1: If the control module 22 does not receive the first feedback signal, it means that the wafer warpage is insufficient, the wafer thickness is too small, the probe height is too high, and the probe has not yet contacted the bump. The second control signal is sent directly to control the probe head to move at the second speed value.

[0046] Scenario 2: The control module 22 receives the first feedback signal, indicating that the low-speed switch has been completed. The speed adjustment will not be repeated, and only the pressure data will be continuously monitored.

[0047] Third timing phase (stopping movement phase): After generating the first feedback signal, the pressure detection unit 211 continuously detects the pressure value between the probe head and the wafer, and the control module 22 acquires the pressure value detected by the pressure detection unit 211 in real time. The control module 22 determines whether the acquired real-time pressure value is within a preset first pressure threshold range; When the real-time pressure value is less than the minimum value of the first pressure threshold range, it is determined that there is poor contact or a loose connection. The machine is not stopped, and the probe head continues to press down slightly to compensate for the pressure while maintaining the second speed value. The pressure is continuously collected and re-evaluated. When the real-time pressure value is within the first pressure threshold range, it is determined that the probe head has reached safe and effective contact with the wafer bump. The control module 22 sends a stop signal to the Z-axis vertical motion execution module 20. After receiving the stop signal, the Z-axis vertical motion execution module 20 controls the probe head to stop moving; the Z-axis servo is locked, and the probe head maintains its current height. When the real-time pressure value exceeds the maximum value of the first pressure threshold range, it is determined to be overpressured, posing a risk of damaging the wafer. A shutdown signal is then sent directly to stop the pressure and prevent the microbumps from being crushed.

[0048] Fourth timing phase (overtravel shutdown phase): To prevent the probe from pressing down indefinitely and crashing into the machine due to pressure closed-loop failure (such as complete loss of the protrusion or sensor failure), a hard position limit logic is set.

[0049] Specifically, when the position detection unit 212 detects that the probe head has moved to the termination position, it sends a fourth feedback signal to the control module 22. After receiving the fourth feedback signal, the control module 22 sends a stop signal to the Z-axis vertical motion execution module 20. The Z-axis vertical motion execution module 20 receives the stop signal and controls the probe head to stop moving. At the same time, the control module 22 obtains the pressure value detected by the current pressure detection unit 211. If the pressure value detected by the current pressure detection unit 211 is not within the first pressure threshold range, the control module 22 sends out a warning signal.

[0050] In one specific implementation scheme, the position detection unit 212 continuously detects the Z-axis coordinate of the probe head. Once the probe head moves to the preset termination position, the position detection unit 212 outputs a fourth feedback signal. After receiving the fourth feedback signal, the control module 22 forcibly outputs a stop signal, locking the movement of the probe head and prohibiting further pressing regardless of the current pressure value. After the Z-axis vertical motion actuator stops, the control module 22 determines whether the pressure value is within the first pressure threshold range. If the pressure is not within the threshold range, the test is deemed abnormal, and an audible and visual warning signal is output. If the pressure is within the threshold range, no alarm is issued.

[0051] Fifth timeline phase (early warning trigger phase) There are only two scenarios in which an alert is triggered: Scenario 1: The probe is pressed down to the end position (maximum stroke), but the pressure still does not reach the qualified range; Insufficient pressure: severe wafer warping, bump detachment, probe wear, stage positioning misalignment; Excessive pressure: Leveling failure, probe tip tilt, abnormal protrusion of bumps; The second scenario: speed verification anomaly. After switching to low speed, the second speed V2 cannot be stably reached within the preset speed adjustment time. The control module 22 synchronously outputs a speed anomaly warning, indicating a servo motor or encoder malfunction. Example

[0052] See Figure 2 The leveling mechanism 23 is connected between the Z-axis vertical motion actuator and the probe head, and is used to adjust the tilt angle of the probe head relative to the plane to be measured about the X-axis and / or about the Y-axis, as well as the moving distance along the Z-axis. The X-axis, Y-axis and Z-axis are mutually perpendicular.

[0053] This embodiment further describes the leveling mechanism 23. The leveling mechanism 23 includes a fixed plate 12, a movable plate 14, an elastic reset member 10, fine-tuning bolts 5, and adjusting bolts 13. The fixed plate 12 is fixedly mounted on the output end face 8 of the transmission unit. The fixed plate 12 and the movable plate 14 are connected by the elastic reset member 10, which is preferably a spring, used to provide tension to keep the movable plate 14 in contact with the fixed plate 12. In this embodiment, there are three elastic reset members 10, distributed at 120° intervals along the circumference. There are also three fine-tuning bolts 5, arranged one-to-one with the elastic reset members 10, and the three springs are respectively sleeved on the screws of the three fine-tuning bolts 5. The screw of each fine-tuning bolt 5 passes through the fixed plate 12 and abuts against the movable plate 14, and is fixed by a locking nut 6. The spring is sleeved on the screw of the fine-tuning bolt 5 and is placed between the fixed plate 12 and the movable plate 14. The elastic force of the elastic reset member 10 applies a force toward the movable plate 14 that moves away from the fixed plate 12. By tightening or loosening the fine-adjustment bolts 5, or tightening or loosening the locking nut 6, the compression of the corresponding elastic reset member 10 can be changed, thereby changing the elastic force of the elastic reset member 10, and thus adjusting the distance between the movable plate 14 and the fixed plate 12 at the corresponding position. That is, by adjusting the three fine-adjustment bolts 5, the yaw attitude of the movable plate 14 around the X-axis and around the Y-axis can be changed independently, and the overall movement along the Z-axis can be achieved.

[0054] Specifically, when the line connecting two of the fine-tuning bolts 5 is set as the X-axis direction, adjusting the screw-in depth of the third fine-tuning bolt 5 alone will cause the movable plate 14 to sway around the X-axis direction, thus adjusting the pitch angle. If the third fine-tuning bolt 5 is kept stationary, adjusting the two fine-tuning bolts 5 distributed along the X-axis direction, so that one side is screwed in while the other side is simultaneously screwed out, will cause the movable plate 14 to sway around the Y-axis direction, thus adjusting the tilt angle. Simultaneously and equally screwing in or out all three fine-tuning bolts 5 will change the overall distance between the movable plate 14 and the fixed plate 12 in the Z-axis direction, thus adjusting the movement distance of the probe head 9 along the Z-axis direction. When the fine-tuning bolt 5 is tightened, the elastic reset member 10 is further compressed, the elastic force increases, and the distance between the movable plate 14 and the fixed plate 12 at that point decreases; when the fine-tuning bolt 5 is loosened, the compression of the elastic reset member 10 decreases, the elastic force decreases, and the distance between the movable plate 14 and the fixed plate 12 at that point increases. Through the above operations, the tilt angle and height of the movable plate 14 can be precisely adjusted at the micro-nano level.

[0055] Adjusting bolt 13 acts between movable plate 14 and fixed plate 12 to lock or loosen movable plate 14 in the X direction. The X direction is the first direction in the horizontal plane, consistent with the lateral movement direction of the wafer testing platform. When adjusting bolt 13 is in the loose state, fine-tuning bolt 5 is allowed to freely adjust the tilt angle and height of movable plate 14; when adjusting bolt 13 is in the locked state, it fixes the relative position of movable plate 14 and fixed plate 12 in the X direction, thereby locking the posture and height adjusted by fine-tuning bolt 5 and maintaining the stability of probe head 9. Example

[0056] This embodiment further describes the position detection unit 212 and the speed detection unit 213. The position detection unit 212 is at least one of an optical grating ruler, a magnetic grating ruler, or a laser interferometer; in this embodiment, the position detection unit 212 is specifically an optical grating ruler. The speed detection unit 213 is an encoder; in this embodiment, the speed detection unit 213 is specifically a rotary encoder mounted on the output shaft of the servo motor 1. Example

[0057] See Figure 2 and Figure 3 This embodiment further describes the pressure detection unit 211. The pressure detection unit 211 includes at least one force sensor 7; when multiple force sensors 7 are included, they are mounted in the same plane and distributed circumferentially. Specifically, in this embodiment, the force sensor 7 is a capacitive force sensor 7. The force sensor 7 is fixedly mounted on the same plane of the fixed plate 12, with its detection end facing the movable plate 14. The pressure exerted by the movable plate 14 during its movement directly acts on the force sensor 7, causing the force sensor 7 to generate a detection value. Example

[0058] See Figure 4 This embodiment provides a closed-loop force control method for wafer bump probes, used to control the apparatus of any one of embodiments 1 to 5 above. The method includes the following steps S1 to S4.

[0059] S1. Obtain the preset first speed value, second speed value, first pressure threshold range, initial position, first position, and termination position; S2. Obtain the real-time position of the probe head. When the probe head is in the initial position, generate a first control signal to control the probe head to move from the initial position toward the wafer at a first speed value. S3. Obtain the preset speed adjustment judgment conditions and the probe head's operating parameters. When the probe head's operating parameters meet the speed adjustment judgment conditions, generate a second control signal to control the probe head to move toward the wafer at a second speed value. In one specific embodiment, the operating parameters of the probe head are real-time pressure parameters, and the speed adjustment determination condition is that when the pressure value generated by the probe head contacting the wafer is detected for the first time, a second control signal is generated. In one specific embodiment, the operating parameters of the probe head are real-time position parameters, and the speed adjustment determination condition is that when the real-time position parameters of the probe head are at the first position, a second control signal is generated.

[0060] Specifically, generating the second control signal to control the probe head to move toward the wafer at a second speed value also includes the following steps: S301. When the speed adjustment judgment condition is triggered, obtain the real-time moving speed value of the probe head and the preset speed adjustment time. S302. Determine whether the real-time moving speed value has reached the second speed value. When the real-time moving speed value reaches the second speed value within the preset speed adjustment time, stop acquiring the real-time speed value of the probe head and control the probe head to move at a constant speed. When the real-time moving speed value does not reach the second speed value within the preset speed adjustment time, adjust the moving speed of the probe head until it reaches the second speed value.

[0061] S4. Real-time acquisition of the pressure value between the probe head and the wafer, and determination of whether the pressure value is within the preset first pressure threshold range; When the pressure value is within the first pressure threshold range, the control probe head stops moving.

[0062] Specifically, it also includes the following steps: S401. Obtain the real-time position of the probe head; S402. When the real-time position of the probe head reaches the termination position, the pressure value between the probe head and the wafer is obtained. If the current pressure value is not within the first pressure threshold range, an early warning signal is sent out.

[0063] This application also discloses a computer-readable storage medium, which stores a computer program, wherein when the computer program is executed by a processor, it implements a wafer bump probe closed-loop force control method according to the above embodiments.

[0064] The computer program can be stored in a computer-readable medium. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or certain middleware. The computer-readable medium includes any entity or system capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the computer-readable medium includes, but is not limited to, the above-mentioned components.

[0065] The wafer bump probe closed-loop force control method of the above embodiment is stored in the computer-readable storage medium and loaded and executed on the processor to facilitate the storage and application of the above method.

[0066] This application also discloses an electronic device in which a computer program is stored in a computer-readable storage medium. When the computer program is loaded and executed by a processor, it implements the above-mentioned closed-loop force control method for wafer bump probes.

[0067] The electronic device can be a desktop computer, a laptop computer, or a cloud server, and includes, but is not limited to, a processor and a memory. For example, the electronic device may also include input / output devices, network access devices, and buses.

[0068] The processor can be a central processing unit (CPU). Of course, depending on the actual use, it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc., and this application does not limit it.

[0069] The memory can be an internal storage unit of an electronic device, such as a hard disk or RAM, or an external storage device, such as a plug-in hard disk, smart memory card (SMC), secure digital card (SD), or flash memory card (FC) equipped on the electronic device. Furthermore, the memory can be a combination of an internal storage unit and an external storage device. The memory is used to store computer programs and other programs and data required by the electronic device. The memory can also be used to temporarily store data that has been output or will be output. This application does not limit this.

[0070] In this electronic device, the wafer bump probe closed-loop force control method of the above embodiment is stored in the memory of the electronic device and loaded and executed on the processor of the electronic device for convenient use.

[0071] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A closed-loop force control system for wafer bump probes, characterized in that, include: Z-axis vertical motion execution module (20), detection module (21) and control module (22); The Z-axis vertical motion execution module (20) and the detection module (21) are both electrically connected to the control module (22); The control module (22) is preset with a first speed value, a second speed value, and a first pressure threshold range; The Z-axis vertical motion execution module (20) is configured to receive a first control signal from the control module (22) and drive the probe head to move toward the wafer at a first speed value. The first control signal is a signal that controls the probe head to make an initial movement. The detection module (21) includes a pressure detection unit (211), which is configured to generate a first feedback signal when the pressure value generated by the probe head contacting the wafer is detected for the first time, and send the first feedback signal to the control module (22). The control module (22) is configured to generate a second control signal when a first feedback signal is received, and the Z-axis vertical motion execution module (20) is configured to receive the second control signal and drive the probe head to move toward the wafer at a preset second speed value; The pressure detection unit (211) is also configured to continuously detect the pressure value between the probe head and the wafer after the first feedback signal is generated; The control module (22) is also configured to acquire the pressure value detected by the pressure detection unit (211) in real time and determine whether the pressure value is within the preset first pressure threshold range. When the pressure value is within the first pressure threshold range, the control module (22) sends a stop signal to the Z-axis vertical motion execution module (20). The Z-axis vertical motion execution module (20) is configured to receive the stop signal and control the probe head to stop moving.

2. The wafer bump probe closed-loop force control system according to claim 1, characterized in that, The control module (22) has a preset first position, and the detection module (21) further includes a position detection unit (212). The position detection unit (212) is configured to generate a second feedback signal when the probe head is detected to move to the first position, and send the second feedback signal to the control module (22). The control module (22) is configured to determine whether a first feedback signal is received when a second feedback signal is received; if no first feedback signal is received, the probe head is driven to move toward the wafer at a preset second speed value. The pressure detection unit (211) is also configured to continuously detect the pressure value between the probe head and the wafer after the position detection unit (212) generates the second feedback signal.

3. The wafer bump probe closed-loop force control system according to claim 2, characterized in that, The control module (22) also has a preset starting position; the position detection unit (212) is also configured to detect the position of the probe head in real time. When the position of the probe head is the starting position, the position detection unit (212) sends a third feedback signal to the control module (22). When the position of the probe head is the first position, the position detection unit (212) sends a second feedback signal to the control module (22). The control module (22) is configured to control the probe head to move at a first speed value when it receives the third feedback signal, and to control the probe head to move at a second speed value when it receives the second feedback signal.

4. The wafer bump probe closed-loop force control system according to claim 2, characterized in that, The control module (22) also has a preset termination position. The position detection unit (212) is also configured to send a fourth feedback signal to the control module (22) when it detects that the probe head has moved to the termination position. The control module (22) is configured to send a stop signal to the Z-axis vertical motion execution module (20) after receiving the fourth feedback signal. The Z-axis vertical motion execution module (20) is configured to receive the stop signal and control the probe head to stop moving. At the same time, the control module (22) obtains the pressure value detected by the current pressure detection unit (211). If the pressure value detected by the current pressure detection unit (211) is not within the first pressure threshold range, the control module (22) sends out a warning signal.

5. A wafer bump probe closed-loop force control system according to claim 4, characterized in that, The system also includes a leveling mechanism (23). The Z-axis vertical motion execution module (20) is a Z-axis vertical motion actuator. The leveling mechanism (23) is connected between the Z-axis vertical motion actuator and the probe head (9). It is used to adjust the tilt angle of the probe head (9) relative to the plane to be measured around the X-axis direction and / or around the Y-axis direction, as well as the moving distance along the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular.

6. The wafer bump probe closed-loop force control system according to claim 1, characterized in that, The detection module (21) further includes a speed detection unit (213), which is configured to detect the moving speed of the probe head in real time and feed the detection result back to the control module (22). The control module (22) is configured to determine whether the moving speed of the probe head has reached a preset second speed value based on the received detection result. When the moving speed of the probe head has not reached the second speed value, the control module (22) sends a second control signal to the Z-axis vertical motion execution module (20). The Z-axis vertical motion execution module (20) is configured to adjust the moving speed of the probe head according to the second control signal until the moving speed of the probe head reaches the second speed value.

7. The wafer bump probe closed-loop force control system according to claim 1, characterized in that, The pressure detection unit (211) includes at least one force sensor (7); when multiple force sensors (7) are included, the multiple force sensors (7) are installed in the same plane and distributed circumferentially.

8. A wafer bump probe closed-loop force control system according to claim 5, characterized in that, The leveling mechanism (23) includes a fixed plate (12), a movable plate (14), an elastic reset component (10), a fine-tuning bolt (5), and an adjusting bolt (13); The fixed plate (12) and the movable plate (14) are connected by the elastic reset member (10), and multiple elastic reset members (10) are provided along the circumferential direction; The fine-tuning bolts (5) are provided one-to-one with the elastic reset members (10); The adjusting bolt (13) acts between the movable plate (14) and the fixed plate (12).

9. A closed-loop force control method for wafer bump probes, said method being based on any one of the closed-loop force control systems for wafer bump probes according to claims 1 to 8, characterized in that, Includes the following steps: S1. Obtain the preset first speed value, second speed value, first pressure threshold range, initial position, first position, and termination position; S2. Obtain the real-time position of the probe head. When the probe head is in the initial position, generate a first control signal to control the probe head to move from the initial position toward the wafer at a first speed value. S3. Obtain the preset speed adjustment judgment condition and the probe head's operating parameters. When the probe head's operating parameters meet the speed adjustment judgment condition, generate a second control signal to control the probe head to move toward the wafer at a second speed value. S4. Real-time acquisition of the pressure value between the probe head and the wafer, and determination of whether the pressure value is within the preset first pressure threshold range; When the pressure value is within the first pressure threshold range, the control probe head stops moving.

10. A closed-loop force control method for wafer bump probes according to claim 9, characterized in that, The operating parameters of the probe head are real-time pressure parameters, and the speed adjustment determination condition is that when the probe head first detects pressure value generated by contacting the wafer, a second control signal is generated.

11. A closed-loop force control method for wafer bump probes according to claim 9, characterized in that, The operating parameters of the probe head are real-time position parameters, and the speed adjustment determination condition is that when the real-time position parameter of the probe head is at the first position, a second control signal is generated.

12. The wafer bump probe closed-loop force control method according to claim 9, characterized in that, The process of generating a second control signal to control the probe head to move toward the wafer at a second speed value also includes the following steps: S301. When the speed adjustment judgment condition is triggered, obtain the real-time moving speed value of the probe head and the preset speed adjustment time. S302. Determine whether the real-time moving speed value has reached the second speed value. When the real-time moving speed value reaches the second speed value within the preset speed adjustment time, stop acquiring the real-time speed value of the probe head and control the probe head to move at a constant speed. When the real-time moving speed value does not reach the second speed value within the preset speed adjustment time, adjust the moving speed of the probe head until it reaches the second speed value.

13. The closed-loop force control method for wafer bump probes according to claim 9, characterized in that, It also includes the following steps: S401. Obtain the real-time position of the probe head; S402. When the real-time position of the probe head reaches the termination position, the pressure value between the probe head and the wafer is obtained. If the current pressure value is not within the first pressure threshold range, an early warning signal is sent out.

14. A smart terminal, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements a closed-loop force control method for wafer bump probes as described in any one of claims 9 to 13.

15. A computer-readable storage medium, characterized in that, It includes a readable storage medium and a computer program stored on the readable storage medium and running thereon, the computer program being loaded and executed by a processor to implement a closed-loop force control method for wafer bump probes as described in any one of claims 9 to 13.

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