Probe station and monitoring method

Abstract

This application relates to the field of semiconductor testing equipment and proposes a probe station and monitoring method. The probe station includes a base, a test frame, a wafer stage module, a probe module, and an image acquisition module. The test frame includes an integrally formed frame and a mounting platform. The frame is connected to the base, and the test frame and base enclose a receiving cavity. The mounting platform has a through slot communicating with the receiving cavity. The wafer stage module is located in the receiving cavity and includes a first driving component connected to the base and a wafer stage connected to the first driving component. The probe module includes a second driving component and a probe. The second driving component is connected to the mounting platform, and the probe is connected to the second driving component. The image acquisition module is connected to the mounting platform and includes an acquisition unit located above the through slot. The monitoring method includes four steps: calibration, verification, calculation, and output, used to monitor the deformation of the probe station. The probe station and monitoring method of this application can make the test results more reliable.

Description

Technical Field

[0001] This application relates to the field of semiconductor testing equipment, specifically to a probe station and a monitoring method. Background Technology

[0002] In the field of semiconductor testing technology, probe stations are typically used to contact the electrodes of wafer chips to perform electrical testing on the chips. This allows for the identification and rejection of defective chips during wafer manufacturing, thereby improving packaging yield. However, current probe station test fixtures usually employ a split connection structure. This split connection structure is prone to slight movement or deformation under external stimuli or impacts, leading to inaccurate contact positions between the probes and electrodes, resulting in poor testing accuracy and reliability. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a probe station that can improve testing accuracy and make test results more reliable.

[0004] This application also proposes a monitoring method for monitoring the deformation of the aforementioned probe station.

[0005] The probe station according to an embodiment of this application includes a base, a test frame, a stage module, a probe module, and an image acquisition module;

[0006] The test frame includes an integrally formed frame and a mounting platform. The frame is connected to the base. The test frame and the base together enclose a receiving cavity that runs through the Y-axis. The mounting platform is provided with a through groove along the Z-axis, and the through groove connects to the receiving cavity.

[0007] The wafer stage module is located in the accommodating cavity. The wafer stage module includes a first driving component and a wafer stage. The first driving component is connected to the base, and the wafer stage is connected to the output end of the first driving component. The first driving component is used to drive the wafer stage to move along the X-axis direction and / or the Y-axis direction. The X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

[0008] The probe module includes a second drive assembly and a probe. The second drive assembly is connected to the mounting stage, and the probe is connected to the output end of the second drive assembly. The second drive assembly is used to drive the probe to move along the Z-axis so that the probe can enter or exit the receiving cavity through the through slot.

[0009] The image acquisition module is connected to the mounting platform. The image acquisition module includes an acquisition unit located above the through slot.

[0010] The probe station according to the embodiments of this application has at least the following beneficial effects: the wafer stage is used to carry the wafer, the first driving component is used to drive the wafer stage to move along the X-axis and / or Y-axis in the accommodating cavity to transport the wafer to the bottom of the through slot, and the second driving component is used to drive the probe to move along the Z-axis and extend into the accommodating cavity through the through slot so that the probe can contact the wafer on the wafer stage for testing. At the same time, the acquisition unit can acquire images of the wafer stage area through the through slot, which is convenient for adjusting the relative position of the wafer stage and the probe. In addition, the wafer stage module is mounted on the frame, and the probe module and the image acquisition module are mounted on the mounting platform. The frame and the mounting platform are integrally formed, which makes the mounting platform more effective in resisting the slight movement or deformation caused by external excitation, vibration and other factors. Therefore, during the testing operation, the relative position of the wafer stage module, the probe module and the image acquisition module is more determined, which facilitates stable image acquisition and precise contact between the probe and the electrode, and is beneficial to improving the testing accuracy and reliability.

[0011] According to some embodiments of this application, the probe station further includes a strain structure and a monitoring module, wherein the strain structure is connected to the side of the mounting platform facing the base, and the strain structure is electrically connected to the monitoring module.

[0012] According to some embodiments of this application, the first drive component includes an X-axis moving platform and a Y-axis moving platform. The stage is connected to the X-axis moving platform. Along the X-axis direction, the X-axis moving platform is movably connected to the Y-axis moving platform. Along the Y-axis direction, the Y-axis moving platform is movably connected to the base. Along the Z-axis direction, the X-axis moving platform is located between the Y-axis moving platform and the stage.

[0013] According to some embodiments of this application, the stage is rotatably connected to the first drive assembly about the Z-axis.

[0014] According to some embodiments of this application, the probe station includes two probe modules, which are arranged at intervals at both ends of the through slot along the X-axis direction.

[0015] According to some embodiments of this application, the probe station further includes a test module, which is connected to the base. Along the Z-axis, the first drive component is provided with a test channel, and the stage covers the side of the test channel away from the test module.

[0016] The slide stage is a transparent structure.

[0017] The monitoring method according to the embodiments of this application is used to monitor the deformation of the probe station in any of the above embodiments. The monitoring method includes calibration, detection, calculation, and output steps:

[0018] Calibration: Based on the reference voltage of the reference branch, adjust the initial voltages of multiple monitoring branches connected in parallel with the reference branch so that each initial voltage is equal to the reference voltage;

[0019] Detection: Detect the voltage of each monitoring branch after deformation of the area to be monitored to obtain the strain voltage;

[0020] Calculation: Based on the reference voltage and strain voltage, calculate the strain state at various points within the monitored area;

[0021] Output: Based on the strain state, output a strain distribution diagram and / or strain distribution matrix characterizing the strain state.

[0022] The monitoring method according to the embodiments of this application has at least the following beneficial effects: the calibration step is used to make the initial voltage of each monitoring branch consistent in order to compensate for the arrangement of the strain structure, so that subsequent steps can uniformly measure the strain degree of the strain structure through voltage changes; the detection step is used to detect the voltage changes of each detection branch, so as to calculate the strain degree at the corresponding monitoring position of each monitoring branch in the calculation step, and then output the strain distribution map and / or strain distribution matrix characterizing the strain state. Thus, the monitoring method of this application can monitor the deformation of the probe station in real time, so as to terminate the detection operation in time when the deformation of the probe station is too large, thereby ensuring the accuracy and reliability of the detection operation.

[0023] According to some embodiments of this application, based on Calculate the strain state at various points within the monitored area;

[0024] in, For strain sensitivity coefficient, Indicates the first The strain value of each monitoring branch Indicates the reference voltage. Indicates the first The strain voltage of each monitoring branch Indicates the first The values ​​representing the strain state monitored by each monitoring branch within the area to be monitored, and .

[0025] According to some embodiments of this application, the reference branch is configured with two reference resistors connected in series, and the reference voltage is measured between the two reference resistors. Each monitoring branch is configured with a strain gauge structure and an adjustable resistor connected in series, and the strain gauge structure is arranged in the area to be monitored.

[0026] In the calibration step, the resistance of the adjustable resistor is adjusted to be equal to the resistance of the strain structure, and the initial voltage is measured between the strain structure and the adjustable resistor.

[0027] According to some embodiments of this application, before arranging the monitoring branch, the upper limit of the resistance of the strain structure is determined and recorded as the first resistance value, and an adjustable resistor with the upper limit of the resistance value as the second resistance value is selected according to the first resistance value.

[0028] The first resistance value is less than the second resistance value.

[0029] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0030] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0031] Figure 1 This is a schematic diagram of the probe station structure according to an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of the structure of the stage module in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the probe module structure according to an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the assembly of the test frame and the base according to an embodiment of this application;

[0035] Figure 5 This is an equivalent schematic diagram of a split-type test fixture;

[0036] Figure 6 This is an equivalent schematic diagram of the integrated test fixture according to an embodiment of this application;

[0037] Figure 7 Simulation diagrams of split-type and integrated test fixtures;

[0038] Figure 8 This is a circuit diagram of the strain structure and monitoring module in an embodiment of this application;

[0039] Figure 9 This is a circuit schematic diagram of the monitoring method according to an embodiment of this application;

[0040] Figure 10 This is a side view of the probe station according to an embodiment of this application;

[0041] Figure 11 This is a bottom view of the probe station according to an embodiment of this application.

[0042] Reference numerals: test frame 100, frame body 110, accommodating cavity 111, mounting platform 120, through groove 121, mounting groove 122, base 130;

[0043] The wafer carrier module 200, the first drive assembly 210, the X-axis moving platform 211, the Y-axis moving platform 212, the test channel 213, and the wafer carrier 220 are included.

[0044] Probe module 300, second drive component 310, probe 320;

[0045] Image acquisition module 400, image acquisition base 410, acquisition device 420, acquisition unit 421. Detailed Implementation

[0046] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0047] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0048] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0049] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0050] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] The embodiments of this application are described below with reference to the accompanying drawings:

[0052] refer to Figures 1 to 4According to an embodiment of this application, the probe station includes a base 130, a test frame 100, a slide stage module 200, a probe module 300, and an image acquisition module 400. The test frame 100 includes an integrally formed frame 110 and a mounting platform 120. The frame 110 is connected to the base 130. The test frame 100 and the base 130 together form a receiving cavity 111 that extends along the Y-axis direction. Along the Z-axis direction, the mounting platform 120 is provided with a through groove 121 that connects to the receiving cavity 111. The stage module 200 is located in the accommodating cavity 111. The stage module 200 includes a first driving component 210 and a stage 220. The first driving component 210 is connected to the base 130, and the stage 220 is connected to the output end of the first driving component 210. The stage 220 is used to carry the workpiece to be tested (e.g., a wafer). The first driving component 210 is used to drive the stage 220 to move along the X-axis and / or Y-axis to adjust the position of the stage 220, so that the stage 220 can move to the underside of the through slot 121 for testing, or move out of the underside of the through slot 121. The X-axis, Y-axis and Z-axis are perpendicular to each other.

[0053] The probe module 300 includes a second driving component 310 and a probe 320. The second driving component 310 is connected to the mounting stage 120, and the probe 320 is connected to the output end of the second driving component 310. The second driving component 310 is used to drive the probe 320 to move along the Z-axis direction so that the probe 320 can enter or exit the receiving cavity 111 through the through slot 121. Thus, when the first driving component 210 drives the wafer stage 220 to move below the through slot 121, the second driving component 310 drives the probe 320 to approach the wafer stage 220 so that the probe 320 contacts the electrode of the wafer core, thereby realizing the power-on test of the core. The image acquisition module 400 is connected to the mounting stage 120. The image acquisition module 400 includes an acquisition unit 421, which is located above the through slot 121. During the movement and testing of the probe 320, the acquisition unit 421 acquires images of the area of ​​the stage 220 through an optical lens. The acquired images are transmitted to the controllers of the first drive component 210 and the second drive component 310 through signal lines. Based on the acquired images, the relative positions of the stage 220 and the probe 320 can be adjusted to make their alignment more accurate.

[0054] Based on the above, the integrally formed structural feature of the test fixture 100 in this application eliminates the assembly process between the fixture 110 and the mounting platform 120, resulting in higher assembly efficiency. On the other hand, it enhances the overall structural rigidity of the test fixture 100, enabling the mounting platform 120 to effectively resist minor movements or deformations caused by external excitations, vibrations, and other factors. Consequently, during testing, the mounting platform 120 can more stably support the probe module 300 and the image acquisition module 400, resulting in a more definite relative positional relationship between the stage module 200, the probe module 300, and the image acquisition module 400. The images acquired by the acquisition unit 421 can more accurately reflect the relative position of the probe 320 and the wafer core electrode. Based on the more accurate images, the alignment of the probe 320 and the core electrode can be adjusted more precisely, thereby improving the accuracy and reliability of the test.

[0055] refer to Figures 1 to 4 Specifically, during assembly, the wafer stage module 200 is first assembled with the base 130, and then the base 130 is connected to the test fixture 100. The first drive assembly 210 drives the wafer stage 220 in ways including but not limited to linear motor structure, ball screw drive structure, or synchronous belt drive structure. The receiving cavity 111 extends along the Y-axis to avoid movement of the wafer stage 220, thereby ensuring the loading and unloading of wafers on the wafer stage 220. The second drive assembly 310 can be driven in the same way as the first drive assembly 210, or a cylinder or electric push rod can be used as the drive structure. The acquisition unit 421 can be an acquisition structure composed of an industrial camera and a lens. When the stage 220 and the probe 320 are adjusted in position, the image information acquired by the acquisition unit 421 can provide real-time position feedback for the position adjustment of the acquisition unit 421 and the probe 320. This is beneficial for operators or control systems to calibrate the position parameters of the stage 220 and the probe 320, so that the contact position between the probe 320 and the wafer electrode is more in line with the test requirements, and the movement and positioning of the stage 220 is more accurate.

[0056] refer to Figures 4 to 6 Compared to the separate structure of the frame 110 and the mounting platform 120, the integrated test frame 100 of this application has a more stable structure, as detailed below:

[0057] For the split-type test frame 100, the frame 110 and the mounting platform 120 are equivalent to a simply supported beam structure. For example, in the split-type test frame 100, the frame 110 and the mounting platform 120 are connected by bolts or other connectors. If the mounting platform 120 is subjected to a load along the Z-axis, the mounting platform 120 will have a tendency to bend or deform. The bolts or other connectors cannot completely constrain the connection between the mounting platform 120 and the frame 110. Therefore, based on the lever principle, there will be a hinged rotational motion at the connection between the mounting platform 120 and the frame 110. That is, along the Y-axis, the two ends of the mounting platform 120 and the frame 110 that are connected are equivalent to hinges.

[0058] Furthermore, for the simply supported beam structure of the equivalent test fixture 100, it is set at... The deflection function at the location is Then uniformly distributed load The deflection function acting on the entire beam is: ;

[0059] in, For deflection, The unit load acting on the simply supported beam, For Young's modulus, Let the moment of inertia of the cross section be... This represents the panel width.

[0060] According to the deflection function above, in The maximum deflection (i.e., the maximum deformation of a simply supported beam) is found at the point where the beam has the maximum deflection. Substituting this value, the maximum deflection is: .

[0061] For the integrally molded test frame 100 in this application, the connection between the mounting platform 120 and the frame 110 is set as opposite ends A and B. Based on the integrally molded structure, the deflection and rotation angle of ends A and B are 0. Taking end B as an example, the maximum deflection of the integrally molded test frame 100 in this application is calculated as follows:

[0062] Based on structural equivalence, end B can be equivalent to... and ,in The supporting force of frame 110 on end B of mounting platform. The bending moment experienced by the mounting platform 120 at end B, thus ,and Therefore, it can be concluded that ;

[0063] The deflection function under the action is: ;

[0064] The deflection function under the action is: ;

[0065] Deflection function under action: ;

[0066] and then, , , The deflection function under the action of the resultant force is: ,Will Substituting into the above resultant force deflection function, we can obtain that... ;

[0067] After sorting, we can obtain ;

[0068] Further calculate the maximum deformation (i.e.) (place), substituting it in, we can know ;

[0069] Based on the above, the ratio of the cross-sectional shape to the maximum deformation of this application is as follows: ;

[0070] Therefore, the deformation of the mounting platform 120 in this application is only [amount missing] compared to the split-type solution. .

[0071] It should be noted that, under static conditions, unit load can be understood as unit mass. and gravitational acceleration The product; under dynamic conditions, acceleration must be considered for unit load, if the acceleration under dynamic conditions is... The unit load under dynamic conditions should be Since dynamic calculations are based on dynamic force equilibrium and linearity, the calculation method for dynamic calculations is the same as for static calculations, using the unit load gravitational acceleration. Replace with dynamic acceleration That's all; I won't go into details here.

[0072] Reference Figure 7 This application also provides a comparison of simulation results based on the split-type test frame 100 and the integrated test frame 100 of this application. Based on the simulation results, it can be seen that the ratio of the maximum deformation of the split-type (B) and the integrated type (A) is 0.0098596 / 0.001923=5.13, which is close to the theoretical value, to further confirm that the integrated test frame of this application is superior to the split-type test frame.

[0073] refer to Figure 1In some embodiments, the probe station also includes a strain structure and a monitoring module. The strain structure is connected to the side of the mounting stage 120 facing the base 130, and the strain structure is electrically connected to the monitoring module. The strain structure can be a strain gauge, fiber optic sensor, laser sensor, or other structure capable of deformation detection. The strain structure and monitoring module are provided to facilitate monitoring of the deformation of the mounting stage 120, so that the test can be stopped when the mounting stage 120 undergoes a large deformation, thus ensuring the accuracy and reliability of the test structure.

[0074] For example, if a strain gauge is used, the strain gauge is electrically connected to the monitoring module. When the mounting platform 120 deforms, the strain gauge deforms along with the mounting platform 120, which in turn causes the resistance value of the strain gauge to change. The monitoring module monitors the strain of the mounting platform 120 by detecting the change in the resistance value of the strain gauge.

[0075] If an optical fiber sensor is used, the optical fiber sensor includes a fiber optic grating. The fiber optic grating is fixed on the side of the mounting platform 120 facing the base 130. When the mounting platform 120 deforms, the fiber optic grating deforms along with the mounting platform 120, causing the grating to change periodically, which in turn changes the wavelength of the reflected wave. The monitoring module can monitor the deformation of the mounting platform 120 by analyzing the change in the wavelength of the reflected wave.

[0076] If a laser sensor is used, the transmitter and receiver of the laser sensor are positioned opposite each other on the base 130, and the laser beam path of the laser sensor passes through the side surface of the mounting platform 120 facing the base 130. The laser sensor forms a signal connection with the monitoring module. When the mounting platform 120 deforms, the position of the side surface of the mounting platform 120 facing the base 130 changes, causing the phase of the laser beam after reflection on the surface to change. By measuring the phase change, the monitoring module can accurately measure the minute deformation of the mounting platform 120.

[0077] The monitoring principle in this application will be further explained in detail below, taking the combination of strain gauges and monitoring modules as an example:

[0078] refer to Figure 8 and Figure 10 Along the Z-axis, strain gauges are attached to the underside of the mounting platform 120. Multiple strain gauges can be attached to the underside of the mounting platform 120, and the strain gauges are arranged at intervals. The arrangement methods include, but are not limited to: arranging them at intervals along the X-axis, arranging them at intervals along the Y-axis, or distributing them in an array under the mounting platform 120, so that multiple strain gauges can correspond to different areas under the mounting platform 120, thereby realizing the monitoring of the strain conditions at various points under the mounting platform 120.

[0079] The strain gauge consists of multiple reciprocating resistance wires forming a wire grid structure. When the mounting platform 120 bends downwards and deforms, the strain gauge deforms along with the mounting platform 120. At this time, the strain gauge is stretched, and the internal resistance wires become thinner due to the stretching, increasing the strain gauge's resistance value. The specific monitoring module includes a reference branch and multiple monitoring branches, with each monitoring branch connected in parallel with the reference branch. The reference branch contains two reference resistors connected in series. ,and The connection point between the two reference resistors is used as the reference voltage measurement point. Taking the setting of 7 strain gauges as an example, the number of monitoring branches is the same as the number of strain gauges, and each monitoring branch is equipped with an adjustable resistor connected in series with the strain gauge. In each monitoring branch, the voltage of the monitoring branch (e.g., initial voltage and strain voltage) is measured between the adjustable resistor and the strain gauge.

[0080] When the strain gauge experiences strain due to the deformation of the mounting platform 120, its resistance changes accordingly, causing a change in the total resistance of the monitoring branch. Since each monitoring branch is connected in parallel with the reference branch, under stable input voltage conditions, the voltage between the adjustable resistor and the strain gauge in the monitoring branch will change with the change in the total resistance of the monitoring branch. By capturing this voltage change, the monitoring module can measure the change in the strain gauge resistance, thereby assessing the strain degree of the strain gauge and ultimately monitoring the strain degree of the mounting platform 120.

[0081] It should be noted that the reference Figure 8 If the input voltage of the monitoring module is Then, in the reference branch, the voltage between the two reference resistors is... , Corresponding to 7 strain gauges, It corresponds to 7 adjustable resistors.

[0082] refer to Figures 1 to 4 In some embodiments, the first drive component 210 includes an X-axis moving platform 211 and a Y-axis moving platform 212. The stage 220 is connected to the X-axis moving platform 211. Along the X-axis direction, the X-axis moving platform 211 is movably connected to the Y-axis moving platform 212. Along the Y-axis direction, the Y-axis moving platform 212 is movably connected to the base 130. Along the Z-axis direction, the X-axis moving platform 211 is located between the Y-axis moving platform 212 and the stage 220 to drive the stage 220.

[0083] Specifically, the Y-axis moving platform 212 and the base 130 each have a guide groove and a corresponding guide rail. The guide rail slides within the guide groove, forming a sliding guide engagement. A motor and a lead screw and nut transmission mechanism are connected to the base 130, with the nut assembly of the lead screw and nut transmission mechanism fixedly connected to the Y-axis moving platform 212. When the motor starts and drives the lead screw to rotate, the lead screw and nut assembly moves linearly along the Y-axis, thereby causing the Y-axis moving platform 212 to move relative to the base 130 along the Y-axis. Similarly, the X-axis moving platform 211 and the Y-axis moving platform 212 also use a lead screw and nut mechanism to achieve relative movement. Specifically, the X-axis moving platform 211 engages with the guide groove on the Y-axis moving platform 212 via a guide rail, or the Y-axis moving platform 212 engages with the guide groove on the X-axis moving platform 211 via a guide rail, and relative displacement in the X-axis direction is achieved through lead screw and nut transmission.

[0084] Therefore, when the Y-axis moving platform 212 moves relative to the base 130, since the wafer stage 220 is connected to the X-axis moving platform 211, and the X-axis moving platform 211 is connected to the Y-axis moving platform 212, the wafer stage 220 can be moved to adjust its position along the Y-axis. When the X-axis moving platform 211 moves relative to the Y-axis moving platform 212, the wafer stage 220 can be moved to adjust its position along the X-axis. Through the coordinated action of the X-axis moving platform 211 and the Y-axis moving platform 212, the planar position of the wafer stage 220 can be adjusted, so that the test position of the wafer carried by the wafer stage 220 is aligned with the through slot 121 on the mounting stage 120, thereby realizing the detection of wafer chips at different positions on the wafer.

[0085] refer to Figures 1 to 4 In some embodiments, the wafer stage 220 is rotatably connected to the first drive assembly 210 around the Z-axis to realize the rotational movement of the wafer stage 220 around the Z-axis, further improving the flexibility of the wafer stage 220 in position adjustment.

[0086] Specifically, the first drive assembly 210 includes an X-axis moving platform 211 and a Y-axis moving platform 212. Around the Z-axis, a slide stage 220 is rotatably connected to the X-axis moving platform 211. Along the Z-axis, the side of the X-axis moving platform 211 closest to the slide stage 220 has a circular groove that matches the outer periphery of the slide stage 220. The bottom area of ​​the slide stage 220 is embedded in this circular groove, allowing the slide stage 220 to rotate relative to the X-axis moving platform 211 around the Z-axis. The outer peripheral wall of the slide stage 220 has an annular toothed structure. A drive motor is fixedly mounted on the X-axis moving platform 211, and the motor's output shaft is connected to the outer peripheral wall of the slide stage 220 via a synchronous belt. The tension of the synchronous belt is adjusted by a tension bearing on the X-axis moving platform to ensure that the synchronous belt maintains effective tension throughout the transmission process.

[0087] When the motor starts, the drive wheel drives the synchronous belt to rotate. The synchronous belt, through meshing, drives the wafer stage 220 to rotate around the Z-axis, thereby adjusting the angular position of the wafer on the wafer stage 220. Thus, the position adjustment of the wafer stage 220 includes translational adjustment along the X-axis and Y-axis, as well as rotational adjustment around the Z-axis. This provides both position and angle adjustment capabilities within a two-dimensional plane, further improving the flexibility of the wafer stage 220's position adjustment. This allows the test die on the wafer to be adjusted to the optimal angle through rotation, achieving more accurate alignment with the probes 320 of the probe module 300.

[0088] During the power-on testing of the wafer core, after the stage 220 is adjusted to the target position by the X-axis moving platform 211 and the Y-axis moving platform 212, the wafer angle can be further finely adjusted by rotating the stage 220 around the Z-axis, so that the electrodes of the wafer core are completely aligned with the axis of the probe 320. This is beneficial to improving the stability of electrical signal transmission and the reliability of test results. It can also actively compensate for minor installation deviations of the wafer by means of adjustment, thereby improving the adaptability of the probe station to complex testing scenarios.

[0089] refer to Figures 1 to 4 In other embodiments, to detect the travel and rotation of the stage 220, photoelectric sensors are provided at the end of the guide rail or circumferentially on the stage 220. Specifically, the photoelectric sensor includes a transmitter and a receiver, and can adopt a through-beam or reflective structure design: For linear motion detection, a photoelectric sensor is installed at the end of the guide rail (i.e., the travel limit position) of the X-axis moving platform 211 or the Y-axis moving platform 212, with the transmitter and receiver respectively located on both sides or the same side of the guide rail. When the stage 220 moves to the end of the guide rail with the moving platform, the edge of the stage 220 or the moving platform triggers the sensor, causing it to generate a change in electrical signal. For rotation detection, an annular sensing area is provided on the circumferential edge of the stage 220, and a photoelectric sensor is installed on the corresponding X-axis moving platform 211. By detecting the scale or mark of the annular area, the rotation angle of the stage 220 can be monitored in real time.

[0090] refer to Figures 1 to 4 In some embodiments, the probe stage includes two probe modules 300. Along the X-axis, the probe modules 300 are spaced apart at both ends of the through slot 121. Through the independent driving and cooperative operation of the two probe modules 300, the probe 320 can be more accurately aligned with the electrodes of the wafer core.

[0091] Specifically, the through slot 121 passes through the mounting stage 120 and connects to the receiving cavity 111 to expose the wafer on the wafer stage 220. Along the X-axis direction, mounting slots 122 are respectively provided at the left and right ends of the through slot 121. The second drive components 310 of the two probe modules 300 are installed in the mounting slots 122 one by one, and each second drive component 310 independently drives one probe 320 to move along the Z-axis direction, so that the position adjustment of the two probes 320 in the Z-axis direction is decoupled from each other (i.e., the two probes 320 can have different Z-axis positions) to adapt to the differences in height or spatial position of the wafer core electrode.

[0092] Each second drive assembly 310 includes a drive motor, a conveyor belt, a lead screw and nut mechanism, and a probe holder. The drive motor is fixed to the probe holder, and its output shaft is connected to the drive wheel. The conveyor belt surrounds the drive wheel and the driven wheel at the end of the lead screw, forming a transmission connection. When the drive motor rotates, the conveyor belt drives the lead screw to rotate, and the lead screw and nut pair converts the rotational motion into linear motion along the Z-axis, thereby driving the probes 320 connected to the nut pair to move independently up and down, achieving precise adjustment of their respective Z-axis positions. This effectively adapts to electrode height differences caused by warpage, uneven thickness, and other factors on the wafer surface.

[0093] The probe holder can adopt a precision slide structure, and its fine adjustment function is realized through a micrometer mechanism. The fixed base plate of the precision slide is connected to the bottom of the mounting groove 122. The slide body slides with the fixed base plate through a linear guide rail. The micrometer is installed on one side of the fixed base plate, and the screw end of the micrometer is fixed to the slide body, thereby realizing the fine adjustment of the position of the probe 320 along the X-axis or Y-axis to compensate for wafer placement deviation or mechanical assembly error.

[0094] refer to Figure 10 and Figure 11 In some embodiments, the probe station further includes a test module connected to the base 130. Along the Z-axis, the first drive assembly 210 has a test channel 213, and the wafer stage 220 covers the side of the test channel 213 away from the test module. The wafer stage 220 is a transparent structure. Specifically, along the Z-axis, the first drive assembly 210 has a through test channel 213 inside. The test channel 213 is perpendicular to the bearing plane of the wafer stage 220. The wafer stage 220 covers the side of the test channel 213 away from the test module, and the wafer stage 220 is configured as a transparent structure. For example, the wafer stage 220 is made of transparent materials such as glass or quartz to ensure that the detection signal can penetrate the wafer stage 220.

[0095] The test module can be a spectrometer, radiation testing system, or other equipment with optical or X-ray detection functions. When the stage module 200 is moved to the position directly below the mounting stage 120 by the drive of the first drive component 210, the detection signal (such as light, radiation, etc.) emitted by the test module passes upward along the Z-axis through the test channel 213 and shines on the wafer surface through the transparent stage 220, thereby realizing non-contact detection of parameters such as the optical properties and material properties of the wafer.

[0096] Therefore, the probe station of this application can achieve diverse wafer inspections through the cooperation of the test module and the transparent wafer stage 220 without removing the wafer stage 220. Since the wafer stage 220 is made of transparent material and covers the test channel 213, the detection signal does not need to undergo complex optical path adjustments and can directly penetrate the wafer stage 220 to act on the wafer, reducing signal attenuation and positional deviation during the inspection process, thus improving inspection efficiency and data accuracy. The configuration of the test channel 213 provides a dedicated transmission path for the detection signal, avoiding interference with other components and ensuring the stability of the inspection process.

[0097] refer to Figure 1 In some embodiments, the image acquisition module 400 further includes an image acquisition base 410 and an acquisition device 420. The image acquisition base 410 is connected to the mounting stage 120, and the acquisition device 420 is connected to the image acquisition base 410. The acquisition device 420 includes an acquisition section 421, which extends along the Z-axis. The image acquisition base 410 may employ a combination structure of a slide rail and a precision slide table to achieve coarse and fine adjustments to the position of the acquisition device 420 along the X-axis and / or Z-axis, thereby clearly acquiring wafer images. The acquisition device 420 may be a horizontal CCD (Charge-Coupled Device). When two probe modules 300 are arranged at intervals along the X-axis, the acquisition device 420 extends along the Z-axis between the two probe modules 300, so that the acquisition section 421 is located in the area between the two probe modules 300, and the probes 320 of both probe modules 300 are within the image acquisition range of the acquisition section 421.

[0098] refer to Figures 1 to 10 The monitoring method according to the embodiments of this application is used to monitor the deformation of the probe station in any of the above embodiments, specifically, to monitor the deformation of the mounting stage 120. The monitoring method includes four steps: calibration, detection, calculation, and output, as detailed below:

[0099] Calibration: Based on the reference voltage of the reference branch, adjust the initial voltage of multiple monitoring branches connected in parallel with the reference branch so that each initial voltage is equal to the reference voltage. After calibration, the voltage of each monitoring branch is consistent in the initial state, thereby compensating for the deformation during the installation of the strained structure and facilitating the subsequent uniform measurement of the strain degree through voltage changes.

[0100] Detection: The voltage of each monitoring branch after deformation of the area to be monitored is detected to obtain the strain voltage. That is, when the area to be monitored on the mounting platform 120 deforms, the resistance value of the strain structure in the corresponding area changes along with the mounting platform 120, which causes the total resistance of the corresponding monitoring branch to change. Since each monitoring branch is connected in parallel with the reference branch, the voltage at the measurement point between the adjustable resistor in the monitoring branch and the strain structure will change when the input voltage is stable. The changed voltage value is the strain voltage.

[0101] Calculation: Based on the reference voltage and strain voltage, the strain state at each location within the monitored area is calculated, enabling the identification of deformation at different locations based on strain voltage. Specifically, the monitoring module uses the reference voltage determined in the calibration step as a basis, combined with the strain voltage of each monitoring branch obtained in the detection step, to perform calculations through a preset calculation model. It should be understood that the calculation model is established based on the correspondence between resistance change and voltage change, and the correspondence between resistance change of the strain structure and the degree of strain. This model can convert the voltage change of each monitoring branch into the strain value at the corresponding strain gauge location, thereby enabling the identification of deformation at different locations within the monitored area of ​​the mounting platform 120 based on strain voltage, and obtaining the strain state at each location.

[0102] Output: Based on the strain state, output a strain distribution map and / or strain distribution matrix characterizing the strain state. The output results allow operators to directly observe the strain results. At the same time, the monitoring module can compare the strain values ​​at each location with the preset strain upper limit. When the strain value exceeds the preset upper limit, it can promptly issue a signal to stop the measurement operation, ensuring the accuracy and reliability of the test results.

[0103] Specifically, refer to Figure 8 The reference branch uses two precision resistors connected in series. ,and The reference voltage was measured between two precision resistors connected in series. , This is the input voltage. In each monitoring branch, As adjustable resistors, strain gauges are connected in series at different locations within the monitored area, and the strain gauges employ... This indicates that the strain gauge is prone to slight deformation during installation. Therefore, it is necessary to adjust the resistance values ​​of the adjustable resistors in each monitoring branch to ensure proper functioning. , , ... , making When the strained structure deforms, its resistance changes accordingly. Consequently, the strain voltage of the monitoring branch differs from the initial voltage. The strain voltage is the current voltage value of the monitoring branch after the strained structure undergoes strain. Based on this, the degree of strain at various points within the monitored area is assessed. The greater the strain voltage, the greater the degree of strain.

[0104] In addition, refer to Figure 9 During voltage detection, a multi-channel voltage acquisition card can be used to synchronously acquire the voltage of each monitoring branch. Each acquisition channel of the multi-channel voltage acquisition card forms a one-to-one electrical connection with the monitoring point between the adjustable resistor and strain gauge in a monitoring branch, ensuring that the voltage signal of each monitoring branch can be independently and accurately transmitted to the multi-channel voltage acquisition card. When deformation occurs in the area to be monitored, the strain voltage of each monitoring branch is transmitted to the multi-channel voltage acquisition card through the corresponding acquisition channel. The multi-channel voltage acquisition card converts these analog voltage signals into digital signals for subsequent calculation and processing.

[0105] The acquired digital voltage signals are transmitted to the control processing module, which has a built-in preset calculation model. This model is based on the correspondence between the resistance change of the strain gauge and the degree of strain, as well as the correspondence between the resistance change and the voltage change. Since different strain voltages correspond to different resistance changes of the strain gauge, and different resistance changes correspond to different degrees of strain, the control processing module uses this calculation model to process the input digital voltage signals, converting the strain voltage of each monitoring branch into strain degree data at the corresponding location.

[0106] After the calculation is completed, the control processing module transmits the obtained strain degree data to the display unit. Upon receiving this data, the display unit processes it according to preset graphical and matrix rules, outputting a strain distribution diagram and / or strain distribution matrix representing the strain state. By observing the strain distribution diagram and / or strain distribution matrix on the display unit, operators can quickly identify the location of strain anomalies in the mounting platform 120, thereby filtering out parts or the entire machine with abnormalities.

[0107] refer to Figure 8 and Figure 9 In some embodiments, based on Calculate the strain state at various points within the monitored area. For strain sensitivity coefficient, Indicates the first The strain value of each monitoring branch Indicates the reference voltage. Indicates the first The strain voltage of each monitoring branch Indicates the first The values ​​representing the strain state monitored by each monitoring branch within the area to be monitored, and Based on this formula, the strain level of each monitoring branch can be calculated.

[0108] Specifically, the calculation formulas in this application are discussed and derived:

[0109] definition Under external loads (e.g., movement or deformation of the mounting stage caused by probe modules or external excitation), let the first... The strain value of each monitoring branch (If the strain structure is a strain gauge, then) (This represents the strain value of the strain gauge), from which we can know... ;

[0110] in, The resistance value is based on the change in resistance caused by strain in the strained structure. The resistance of the strained structure in its static state is... ;

[0111] The first was measured The strain voltage of each monitoring branch is: ;

[0112] Combination , It can be known that In this calculation formula, the strain structure varies depending on the material. Thus, by measuring the strain voltage and reference voltage of the monitoring branch, calculating the strain value of the monitoring branch, and outputting the strain distribution map and / or strain distribution matrix characterizing the strain state, the strain degree of the strained structure can be measured, making the measurement more convenient and faster.

[0113] refer to Figure 8 and Figure 9In some embodiments, the reference branch is configured with two reference resistors connected in series, and a reference voltage is measured between the two reference resistors. Each monitoring branch is configured with a strain gauge structure connected in series and an adjustable resistor, with the strain gauge structure arranged within the area to be monitored. In the calibration step, the resistance value of the adjustable resistor is adjusted to be equal to the resistance value of the strain gauge structure, and an initial voltage is measured between the strain gauge structure and the adjustable resistor. Compared to a scheme that achieves virtual balance by pre-setting a correction coefficient in the monitoring module and converting the initial voltage of each monitoring branch to an equivalent value to the reference voltage according to the correction coefficient, this embodiment allows the calibration process to directly act on the monitoring branch where the strain gauge structure is located. This physically cancels out the resistance deviation caused by slight assembly changes in the strain gauge structure, effectively avoiding the problem of the overall balance of the reference branch being broken due to adjusting the reference resistor. It eliminates the need to rely on software algorithms to compensate for potential calculation errors, and the calibration between each monitoring branch does not interfere with each other. When multiple strain gauge structures are arranged, precise balancing can be performed for slight assembly changes in each strain gauge structure, making adjustment more flexible and convenient.

[0114] refer to Figure 8 and Figure 9 In some embodiments, before arranging the monitoring branch, the upper limit of the resistance of the strain structure is determined and recorded as the first resistance value. An adjustable resistor with a second resistance value as its upper limit is then selected based on the first resistance value; wherein the first resistance value is less than the second resistance value. Thus, the adjustable resistor can effectively offset the resistance changes of the strain structure caused by factors such as installation stress during assembly, facilitating deformation monitoring with a uniform voltage and ensuring the accuracy of the monitoring.

[0115] It should be noted that the adjustable resistor can be a sliding rheostat. A sliding rheostat changes the length of the resistance wire connected to the circuit by adjusting the position of the slider, thereby achieving continuous adjustment of the resistance value. The strain gauge can be a strain gauge. The upper limit of the resistance value of the strain gauge refers to the resistance value exhibited when the strain gauge is stretched to its maximum extent. The measurement method can be as follows: the strain gauge is installed in the same way as in actual assembly, simulating pasting onto a test plate. Then, a gradually increasing tensile force is applied to the test plate, causing the strain gauge to be stretched along with the test plate until the strain gauge is about to reach a critical state of irreversible damage (such as wire grid breakage, substrate cracking, etc.). At this point, the resistance value of the strain gauge is measured using a resistance measuring instrument; this resistance value is the upper limit of the resistance value of the strain gauge (i.e., the first resistance value).

[0116] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A monitoring method, characterized in that, It includes a probe station, which comprises a base, a test frame, a slide stage module, a probe module, an image acquisition module, a strain structure, and a monitoring module; The test frame includes an integrally formed frame and a mounting platform. The mounting platform is provided with a monitoring area. The frame is connected to the base. The test frame and the base enclose a receiving cavity that extends along the Y-axis. Along the Z-axis, the mounting platform is provided with a through groove that connects to the receiving cavity. The wafer stage module is located in the accommodating cavity. The wafer stage module includes a first driving component and a wafer stage. The first driving component is connected to the base, and the wafer stage is connected to the output end of the first driving component. The first driving component is used to drive the wafer stage to move along the X-axis direction and / or the Y-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The probe module includes a second drive component and a probe. The second drive component is connected to the mounting stage, and the probe is connected to the output end of the second drive component. The second drive component is used to drive the probe to move along the Z-axis direction so that the probe can enter or exit the receiving cavity through the through slot. An image acquisition module is connected to the mounting platform. The image acquisition module includes an acquisition unit located above the through slot. The monitoring module includes a reference branch and multiple monitoring branches. The strain structure is connected to the side of the mounting platform facing the base, and the strain structure is electrically connected to the monitoring module. The monitoring method includes the following steps: Calibration: Based on the reference voltage of the reference branch, adjust the initial voltage of the multiple monitoring branches connected in parallel with the reference branch so that each initial voltage is equal to the reference voltage; Detection: Detect the voltage of each monitoring branch after deformation of the area to be monitored to obtain the strain voltage; Calculation: Based on the reference voltage and the strain voltage, calculate the strain state at each point within the monitored area; Output: Based on the strain state, output a strain distribution diagram and / or strain distribution matrix characterizing the strain state.

2. The monitoring method according to claim 1, characterized in that, based on Calculate the strain state at each point within the monitored area; in, For strain sensitivity coefficient, Indicates the first The strain value of each of the monitoring branches, This represents the reference voltage. Indicates the first The strain voltage of the monitoring branch, Indicates the first The values ​​characterizing the strain state detected by each of the monitoring branches within the area to be monitored, and .

3. The monitoring method according to claim 1, characterized in that, The reference branch is equipped with two reference resistors connected in series, and the reference voltage is measured between the two reference resistors. Each monitoring branch is equipped with a strain gauge structure and an adjustable resistor connected in series, and the strain gauge structure is arranged in the area to be monitored. In the calibration step, the resistance value of the adjustable resistor is adjusted to be equal to the resistance value of the strain structure, and the initial voltage is measured between the strain structure and the adjustable resistor.

4. The monitoring method according to claim 3, characterized in that, Before arranging the monitoring branch, the upper limit of the resistance of the strain structure is determined and recorded as the first resistance value. Based on the first resistance value, the adjustable resistor with the upper limit of the resistance value being the second resistance value is selected. Wherein, the first resistance value is less than the second resistance value.

5. The monitoring method according to claim 1, characterized in that, The first driving component includes an X-axis moving platform and a Y-axis moving platform. The wafer stage is connected to the X-axis moving platform. Along the X-axis direction, the X-axis moving platform is movably connected to the Y-axis moving platform. Along the Y-axis direction, the Y-axis moving platform is movably connected to the base. Along the Z-axis direction, the X-axis moving platform is located between the Y-axis moving platform and the wafer stage.

6. The monitoring method according to claim 1, characterized in that, The stage is rotatably connected to the first drive assembly about the Z-axis.

7. The monitoring method according to claim 1, characterized in that, The probe station includes two probe modules, which are spaced apart at both ends of the through slot along the X-axis.

8. The monitoring method according to claim 1, characterized in that, The probe station also includes a test module, which is connected to the base. Along the Z-axis, the first drive component has a test channel, and the stage covers the side of the test channel away from the test module. The test module is used for non-contact testing, and the stage is a transparent structure.

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