Probe needle pressure automatic control device and wafer acceptance test system

Abstract

The present application relates to an automatic probe pressure control device and a wafer acceptance test system. The automatic probe pressure control device includes: an image processing device for obtaining a first probe pressure adjustment parameter, wherein the first probe pressure adjustment parameter includes a real-time parameter of the probe tip; and a control device for obtaining a second probe pressure adjustment parameter, and calculating a probe pressure adjustment amount based on the first and second probe pressure adjustment parameters to adjust the probe pressure according to the pressure adjustment amount; wherein the second probe pressure adjustment parameter includes a historical parameter of the needle tip, wherein the historical parameter includes the parameters of the needle tip during factory and use. The present application improves the accuracy of needle pressure adjustment, further ensuring stable wafer / chip testing and reliable data.

Description

Technical Field

[0001] The present application relates to the field of semiconductor testing technology, and in particular to a probe needle pressure automatic control device and a wafer acceptance test system. Background Art

[0002] When using probe cards for wafer / chip electrical testing, probe wear is a common problem due to friction between the probe tip and the probe pad metal. This wear may cause the following effects: (1) Poor contact: Worn probes may not provide good contact, resulting in a decrease in signal transmission quality, which may lead to inaccurate measurement results or test failure. (2) Signal distortion: Worn probes may introduce additional components such as resistance, inductance, or capacitance, changing the characteristics of the circuit, which may cause signal distortion or poor frequency response. (3) Unreliability: Worn probes may cause unstable or disconnected contact, making the test system unreliable, which may lead to frequent interruptions, false alarms, or test errors.

[0003] Usually, before the wear of the probe card reaches the point of scrapping, technicians will manually increase the probe needle pressure to offset the poor contact caused by the wear of the probe card. The existing method usually has the following disadvantages: (1) action can only be taken when the data is found to be unreliable, and it cannot effectively prevent this situation from happening; (2) the amplitude / frequency adjusted by the technicians has no accurate basis, there is a certain degree of uncertainty, and the versatility is poor. Summary of the Invention

[0004] Based on this, it is necessary to provide a probe needle pressure automatic control device and a wafer acceptance test system that can accurately and automatically control the probe needle pressure to address the above technical problems.

[0005] In a first aspect, the present application provides a probe needle pressure automatic control device, comprising:

[0006] an image processing device for acquiring a first needle pressure adjustment parameter of the probe, the first needle pressure adjustment parameter including a real-time parameter of the needle tip of the probe; and a control device for acquiring a second needle pressure adjustment parameter of the probe, calculating a needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, and adjusting the needle pressure of the probe according to the needle pressure adjustment amount;

[0007] The second needle pressure adjustment parameter includes historical parameters of the needle tip, and the historical parameters include parameters of the needle tip before leaving the factory and during use.

[0008] In some embodiments, the needle pressure adjustment amount is a vertical height difference between a current position and an ideal position of the probe pad on the wafer to be tested when the needle tip contacts the probe pad on the wafer to be tested.

[0009] In some embodiments, the first needle pressure adjustment parameter includes a real-time diameter of the needle tip, the second needle pressure adjustment parameter includes a historical diameter of the needle tip, and the control device is specifically configured to:

[0010] Obtaining the real-time diameter and the historical diameter of the needle tip of the probe, and determining the needle diameter change according to the real-time diameter and the historical diameter;

[0011] A needle pressure adjustment amount of the probe is determined based on the needle diameter change amount, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0012] In some embodiments, determining the needle pressure adjustment amount based on the needle diameter change includes:

[0013] When the needle diameter change is greater than or equal to a preset needle diameter change threshold, determining the needle pressure adjustment amount according to the preset step amount;

[0014] When the needle diameter change is less than a preset needle diameter change threshold, no needle pressure adjustment is performed.

[0015] In some embodiments, determining the needle pressure adjustment amount according to the preset step amount includes at least one of the following:

[0016] Determine the needle pressure adjustment amount according to the preset step amount;

[0017] A needle pressure adjustment coefficient is determined according to the real-time diameter and the historical diameter of the needle tip of the probe, and a needle pressure adjustment amount is determined based on the needle pressure adjustment coefficient.

[0018] In some embodiments, the needle pressure adjustment coefficient is calculated by the following formula:

[0019] δ=(D1 tip -D0 tip ) / D1 tip

[0020] Among them, δ is the needle pressure adjustment coefficient, D1 tip is the real-time diameter of the probe tip, D0 tip is the initial diameter of the probe tip.

[0021] In some embodiments, the control device is specifically configured to:

[0022] Obtain the initial length of the needle tip and the incident angle of the needle tip;

[0023] Determine the real-time length of the probe tip when it is worn to a certain state;

[0024] The needle pressure adjustment amount of the probe is calculated based on the real-time length of the needle tip when it is worn to a certain state, the initial length of the needle tip and the incident angle of the needle tip, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0025] In some embodiments, determining the real-time length of the probe tip when it is worn to a certain state includes at least one of the following:

[0026] receiving a real-time length of the needle tip when it is worn to a certain state obtained by an image processing device;

[0027] The real-time length of the needle tip when it is worn to a certain state is determined according to the size parameters of the needle tip before and after wear, and the size parameters of the needle tip before and after wear are determined by the first needle pressure adjustment parameter and the second needle pressure adjustment parameter.

[0028] In some embodiments, determining the real-time length of the needle tip when it is worn to a certain state based on the dimensional parameters of the needle tip before and after wear includes:

[0029] Obtaining the real-time diameter of the needle tip when it is worn to a certain state;

[0030] The real-time length of the needle tip when it is worn to a certain state is calculated based on the initial length of the needle tip, the initial diameter of the needle tip, the diameter of the needle body, and the real-time diameter of the needle tip.

[0031] In some embodiments, the control device is further configured to issue an alarm when the first needle pressure adjustment parameter exceeds a preset wear threshold.

[0032] On the second aspect, the present application also provides a wafer acceptance test system, including a wafer to be tested, a probe station and the probe needle pressure automatic control device as described above, wherein a probe pad is provided on the wafer to be tested, and the probe station is provided with a probe card, and the probes on the probe card can movably contact the probe pads on the wafer to be tested to perform a wafer acceptance test on the wafer to be tested based on the adjusted needle pressure.

[0033] The above-mentioned probe needle pressure automatic control device and wafer acceptance test system calculate the needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter of the probe through the control device, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount. Since the first needle pressure adjustment parameter includes the real-time parameters of the needle tip, and the second needle pressure adjustment parameter includes the historical parameters of the needle tip, and the historical parameters include the parameters of the needle tip before leaving the factory and during use, during the use of the probe, not only can the position of the needle tip be timely and automatically corrected according to its real-time parameters, avoiding the influence of poor contact caused by probe wear, but also, considering that different probes have different suppliers, preparation processes, and balanced contact force (BCF) of their needle tips, and the parameters before leaving the factory and during use are not the same, the real-time parameters of the probe needle tip are combined with the historical parameters of the probe to automatically adjust the needle pressure of the probe during the needle pressure adjustment, thereby improving the accuracy of the needle pressure adjustment and further ensuring the stability of wafer / chip testing and the reliability of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of a probe needle pressure automatic control device in one embodiment;

[0035] Figure 2 A schematic diagram of a probe inserted into a probe pad on a wafer to be tested in one embodiment;

[0036] Figure 3 A schematic diagram of the structure of a probe in one embodiment;

[0037] Figure 4 A schematic diagram of the probe needle pressure before and after adjustment in one embodiment;

[0038] Figure 5 A schematic diagram of an acupressure OD automatic control setting interface in one embodiment;

[0039] Figure 6 is a flow chart of automatic acupressure control in one embodiment;

[0040] Figure 7 This is a schematic diagram of the cross-sectional structure of the probe before the needle pressure is adjusted in one embodiment;

[0041] Figure 8 This is a schematic diagram of the cross-sectional structure of the probe after the needle pressure is adjusted in one embodiment;

[0042] Figure 9 Schematic diagram of the acupressure OD automatic control setting interface in another embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] Many different embodiments or examples for implementing the different features of the present application are provided below. Specific examples of elements and configurations are described below to simplify the present application. Of course, these are merely examples and do not limit the scope of the present application. For example, in the description below, forming a first feature on or above a second feature may include an embodiment in which the first feature and the second feature are formed in direct contact, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the present application may repeat reference numerals and / or text in various examples. This repetition is for the purpose of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0045] A probe station is a precision device used for testing and analyzing semiconductor devices. It is widely used in integrated circuit manufacturing, R&D, and failure analysis. A probe station typically consists of a platform, a probe card, a control system, and a data acquisition system. The platform is used to place the wafer or chip to be tested. The probe card is equipped with multiple fine probes that contact the test points on the wafer through probe pads to perform relevant tests.

[0046] The present application provides an automatic probe pressure control device that can be integrated into the aforementioned probe station as part of the probe station. The automatic probe pressure control device can acquire and monitor the probe's adjustment parameters in real time, calculate the probe's pressure adjustment amount, and perform analysis and adjustment based on the pressure adjustment amount to ensure that the probe remains within the optimal pressure range during testing.

[0047] By controlling the probe pressure, the probe's accurate position is ensured, thereby ensuring good contact between the probe and the test point for electrical signal transmission and measurement. Automatic probe pressure control improves test accuracy and reliability, reduces human intervention, and improves production efficiency and product quality.

[0048] In this embodiment, the probe needle pressure automatic control device includes: an image processing device 12 and a control device 13.

[0049] The image processing device 12 is used to obtain the first needle pressure adjustment parameter of the probe and transmit it to the control device 13. Among them, multiple probes are arranged on the probe card 11, and the probes include a needle body 111 and a needle tip 112. The probes are usually made of gold, aluminum or other conductive materials, and can contact the test points on the wafer or chip to be tested through the probe pad. The multiple probes are fixed and supported by a substrate and a bracket to ensure the stability and precise positioning of the probes. During use, the degree of wear of the probe tip 112 continues to increase, affecting the test effect.

[0050] The image processing device 12 may include an image sensor and an image processor. The image sensor acquires an image of the probe needle tip 112. The image processor is electrically connected to the image sensor. The image processor calculates the needle pressure adjustment amount of the probe based on the acquired image of the needle tip 112 by embedding image processing algorithms such as edge detection, shape analysis, and threshold segmentation. The image processing device 12 can select the most suitable type of image processing device 12 according to specific measurement needs and accuracy requirements, and this application does not limit this. The first needle pressure adjustment parameter includes the real-time parameters of the needle tip 112, such as the real-time diameter and real-time length of the needle tip 112. The real-time parameters of the needle tip 112 change during the use of the needle tip 112 and can be acquired in real time.

[0051] For example, the probe tip 112 may be placed within the field of view of the image processing device 12 , and the focus may be adjusted to obtain a clear image. The edge of the tip 112 may then be automatically identified and its diameter acquired using an edge detection algorithm.

[0052] The control device 13 is used to obtain the second needle pressure adjustment parameter of the probe, which includes the historical parameters of the needle tip 112, including the parameters of the needle tip 112 at the factory and during use. It is understood that the parameters of the needle tip 112 at the factory are the initial parameters of the needle tip 112, which can be dimensional and angular parameters such as the initial diameter and initial length of the needle tip 112, the diameter of the needle body 111, and the angle of incidence of the needle tip 112. Correspondingly, the parameters of the needle tip 112 during use are the dimensional and angular parameters of the needle tip 112 when it is worn to a certain state during use.

[0053] After the first needle pressure adjustment parameter and the second needle pressure adjustment parameter are obtained, the needle pressure adjustment amount of the probe is calculated by combining the first needle pressure adjustment parameter and the second needle pressure adjustment parameter to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0054] Among them, Figures 2 to 4 As shown, the needle pressure OD (overdrive) adjustment amount is the vertical height difference between the current position and the ideal position of the probe pad on the wafer to be tested when the needle tip 112 contacts the probe pad on the wafer to be tested.

[0055] In this embodiment, the needle pressure adjustment amount of the probe is calculated in combination with the first needle pressure adjustment parameter and the second needle pressure adjustment parameter. For example, after obtaining the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, the corresponding needle pressure adjustment amount is obtained by combining the multivariable needle pressure empirical formula or calibration curve related to the first needle pressure adjustment parameter and the second needle pressure adjustment parameter. It can also be calculated in real time based on the size and angle parameters of the probe. The calculation method is not specifically limited in this application.

[0056] In the above embodiment, the control device 13 calculates the needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter of the probe, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount. Since the first needle pressure adjustment parameter includes the real-time parameter of the needle tip 112, and the second needle pressure adjustment parameter includes the historical parameter of the needle tip 112, the historical parameter includes the parameters of the needle tip 112 during delivery and use. Therefore, during the use of the probe, not only can the position of the needle tip 112 be timely and automatically corrected according to its real-time parameter, thereby avoiding the influence of poor contact caused by probe wear, but also, considering that different probes have different suppliers, preparation processes, and balanced contact force (BCF) of their needle tips 112, and the parameters during delivery and use are not the same, the real-time parameters of the probe needle tip 112 are combined with the historical parameters of the probe to automatically adjust the needle pressure of the probe during needle pressure adjustment, thereby improving the accuracy of needle pressure adjustment and further ensuring the stability of wafer / chip testing and the reliability of data.

[0057] Exemplarily, based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, the needle pressure adjustment amount of the probe may be calculated in the following manner.

[0058] Step S11 : obtaining the real-time diameter and the historical diameter of the needle tip 112 of the probe, and determining the needle diameter change according to the real-time diameter and the historical diameter.

[0059] like Figure 3 As shown, since the needle tip 112 is generally conical, the shape of the needle tip 112 changes from thin to thick from the needle head to the needle arm. During the use of the probe card 11, the needle tip 112 of the probe will gradually become thicker due to wear. Therefore, the diameter of the needle tip 112 can be used to characterize the degree of wear of the probe card. The larger the needle diameter, the greater the probe loss.

[0060] In this embodiment, the first needle pressure adjustment parameter includes the real-time diameter of the needle tip 112, and the second needle pressure adjustment parameter includes the historical diameter of the needle tip 112. It will be understood that the needle diameter change may be the difference between the real-time diameter of the needle tip 112 and the historical diameter of the needle tip 112. For example, the needle diameter change may be the difference between the real-time diameter of the needle tip 112 and the initial diameter of the needle tip 112, or the difference between the current real-time diameter of the needle tip 112 and the real-time diameter of the needle tip 112 obtained from the last measurement. By using the needle diameter change as a key parameter for controlling needle pressure, needle pressure can be controlled in real time based on changes in needle diameter, thereby achieving optimal contact between the probe and the needle.

[0061] Step S12: determining a needle pressure adjustment amount of the probe based on the needle diameter change, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0062] In some embodiments, after the needle diameter change is determined, the needle pressure adjustment is not directly triggered. Specifically, when the needle diameter change is greater than or equal to a preset needle diameter change threshold, it indicates that the needle diameter is worn to a degree that can trigger adjustment, and the needle pressure adjustment amount is determined according to the preset step amount. Otherwise, when the needle diameter change is less than the preset needle diameter change threshold, the needle pressure adjustment is not performed. By using the preset needle diameter change threshold, frequent adjustments to the needle pressure due to small changes that may be caused by noise can be avoided, making the system insensitive to small disturbances, thereby enhancing the system's robustness to changes in the external environment, which can improve the stability of the system and the accuracy of the measurement. At the same time, unnecessary adjustment operations are avoided, equipment downtime is reduced, and thus the complexity and adjustment time of the system are reduced.

[0063] For example, the probe needle pressure OD automatic control setting interface is as follows Figure 5 As shown, when OD automatic adjustment is YES, it means that the needle pressure automatic control function is turned on, and when OD automatic adjustment is NO, it means that the needle pressure automatic control function is turned off. Needle diameter change threshold, needle diameter wear threshold (such as the maximum allowable needle diameter) and other needle pressure adjustment parameters can be configured by the user. It can be understood that Figure 5 For illustration only, the probe needle pressure OD automatic control setting interface may include more or fewer components than shown in the figure, or combine certain components, or have a different component configuration.

[0064] The flow chart of automatic acupuncture pressure control by the probe acupuncture pressure automatic control device is as follows Figure 6 shown.

[0065] Step S1, turning on the acupressure automatic control function;

[0066] Step S2 , setting the needle pressure adjustment parameters, including second needle pressure adjustment parameters such as the initial diameter and initial length of the needle tip 112 , the diameter of the needle body 111 , the incident angle of the needle tip 112 and other size and angle parameters.

[0067] Step S3, the control device reads the identification code of the probe card 11 to determine whether the probe is entered into the system for the first time;

[0068] Step S4, measuring the real-time diameter of the probe needle tip 112 as a first needle pressure adjustment parameter, and issuing an alarm when the diameter of the needle tip 112 is greater than or equal to a needle diameter wear threshold;

[0069] Step S5, step S5.1, when the probe is first entered into the system, the diameter of the needle tip 112 is recorded as the initial diameter of the needle tip 112; step S5.2, when the probe is not first entered into the system, the needle diameter change delta is determined based on the real-time diameter and the historical diameter;

[0070] Step 6, step S6.1, when the needle diameter change delta is greater than or equal to the preset needle diameter change threshold, determine the needle pressure adjustment amount OD according to the preset step amount; step S6.2, otherwise, do not trigger OD adjustment;

[0071] Step S7, step S7.1, after OD adjustment, the current diameter of the needle tip 112 is recorded as the historical diameter; step S7.2, when OD adjustment is not performed, the diameter of the needle tip is kept unchanged;

[0072] Step S8, start the acupuncture test.

[0073] Specifically, in some embodiments, determining the needle pressure adjustment amount according to the pre-adjusted step size may be determining the needle pressure adjustment amount according to the preset step size, that is, when the needle pressure adjustment is triggered, the needle pressure is adjusted according to the preset step size.

[0074] In other embodiments, the needle pressure adjustment amount is determined based on the preset step size, and a needle pressure adjustment coefficient can be determined based on the real-time diameter and historical diameter of the needle tip 112 of the probe, and the needle pressure adjustment amount is determined based on the needle pressure adjustment coefficient. In this embodiment, the needle pressure adjustment coefficient is dynamically determined when the needle pressure adjustment is triggered, that is, the needle pressure adjustment step size is not fixed, and the degree of wear affects the needle pressure adjustment step size. The needle pressure adjustment coefficient is determined based on the real-time diameter and historical diameter of the needle tip 112 of the probe. This adaptability ensures that the needle pressure is always maintained at an optimal level under different degrees of wear.

[0075] In this embodiment, when the degree of wear of the probe tip 112 is higher, the contact stability is worse. In this case, the adjustment step size can be increased to increase the needle pressure adjustment coefficient to ensure stable contact between the needle tip 112 and the probe pad. For example, the needle pressure adjustment coefficient is calculated by the following formula:

[0076] δ=(D1 tip -D0 tip ) / D1 tip (1)

[0077] Among them, δ is the needle pressure adjustment coefficient, D1 tip is the real-time diameter of the probe tip 112, D0 tip is the initial diameter of the probe tip 112 .

[0078] Of course, in other embodiments, the calculation method of the needle pressure adjustment coefficient is not limited to this, and can be adaptively configured according to the actual situation of the probe, and this application does not limit it here.

[0079] In some embodiments, the control device 13 is further configured to issue an alarm when the first needle pressure adjustment parameter exceeds a preset wear threshold.

[0080] In this embodiment, when the first needle pressure adjustment parameter exceeds a preset wear threshold, indicating that the wear of the probe tip 112 has exceeded the maximum allowable standard, continued use of the probe will affect measurement accuracy and cannot be overcome by needle pressure adjustment. In this case, an alarm prompt is sent to the user. The alarm prompt can remind the operator to replace or calibrate the probe in a timely manner to maintain measurement accuracy.

[0081] In some embodiments, the needle pressure adjustment amount can be calculated in real time based on the size and angle parameters of the probe. The control device 13 is specifically configured to implement the following steps:

[0082] S21 , obtaining the initial length of the needle tip 112 and the incident angle of the needle tip 112 .

[0083] S22, determining the real-time length of the probe tip 112 when it is worn to a certain state.

[0084] S23, calculating and determining the needle pressure adjustment amount of the probe according to the real-time length of the needle tip 112 when it is worn to a certain state, the initial length of the needle tip 112 and the incident angle of the needle tip 112, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0085] In this embodiment, the wear of the probe tip 112 is not only reflected in changes in diameter, but also affects the length of the tip 112. The first needle pressure adjustment parameter includes the real-time length of the tip 112 when it is worn to a certain state. The second needle pressure adjustment parameter includes the initial length of the tip 112 and the incident angle of the tip 112. The incident angle of the tip 112 is the angle between the axis of the tip 112 and the probe pad (i.e., the horizontal direction). The initial length of the tip 112 and the incident angle of the tip 112 do not change with the wear of the tip 112 and are known constants that can be directly obtained.

[0086] In some embodiments, the real-time length of the needle tip 112 of the probe when it is worn to a certain state can be obtained by the image processing device 12. In this case, the control device 13 receives the real-time length of the needle tip 112 when it is worn to a certain state obtained by the image processing device 12. The acquisition method can be referred to the description of the image processing device 12 acquiring the first needle pressure adjustment parameter of the probe in the above embodiment, and this application does not elaborate on it here.

[0087] like Figure 7 and Figure 8 The figure shows the cross-sectional structure of the probe before and after the needle pressure is adjusted. After obtaining the real-time length of the probe tip 112 when it is worn to a certain state, the needle pressure adjustment amount of the probe can be calculated based on the relationship between similar triangles, as shown in the following formula:

[0088] (2)

[0089] Among them, Δ OD is the needle pressure adjustment amount, L0 is the initial length of the needle tip 112 , L1 is the real-time length of the needle tip 112 when it is worn to a certain state, and θ is the incident angle of the needle tip 112 .

[0090] In some embodiments, the length change is determined based on the real-time length and initial length of the needle tip 112. After the length change is determined, the needle pressure adjustment is not directly triggered. Specifically, when the length change is greater than or equal to a preset length change threshold, it indicates that the needle diameter is worn to a degree that can trigger adjustment. At this time, the needle pressure is adjusted according to the needle pressure adjustment amount. Otherwise, when the length change is less than the preset length change threshold, the needle pressure is not adjusted. The preset length change threshold can avoid frequent adjustments to the needle pressure due to small changes that may be caused by noise, making the system insensitive to small disturbances, thereby enhancing the robustness of the system to changes in the external environment, which can improve the stability of the system and the accuracy of the measurement. At the same time, unnecessary adjustment operations are avoided, equipment downtime is reduced, and thus the complexity and adjustment time of the system are reduced.

[0091] For example, the probe needle pressure OD automatic control setting interface is as follows Figure 9 When OD Auto Adjustment is set to YES, the automatic needle pressure control function is enabled, and when OD Auto Adjustment is set to NO, the automatic needle pressure control function is disabled. Needle pressure adjustment parameters such as the incident angle θ of the needle tip 112, the initial length L0 of the needle tip 112, the length change threshold, and the length wear threshold can all be configured by the user.

[0092] In other embodiments, the real-time length of the needle tip 112 when it is worn to a certain state can be determined based on the dimensional parameters of the needle tip 112 before and after wear. The dimensional parameters of the needle tip 112 before and after wear are determined by a first needle pressure adjustment parameter and a second needle pressure adjustment parameter, and include one or more of the diameter of the needle tip 112, the incident angle of the needle tip 112, and the generatrix length of the needle tip 112 (i.e., the distance from the needle tip 112 to the bottom edge of the needle body 111 on the surface of the needle body 111). Exemplarily, determining the real-time length of the needle tip 112 when it is worn to a certain state based on the dimensional parameters of the needle tip 112 before and after wear includes:

[0093] S221, obtaining the real-time diameter of the needle tip 112 when it is worn to a certain state;

[0094] S222 , calculating the real-time length of the needle tip 112 when it is worn to a certain state based on the initial length of the needle tip 112 , the initial diameter of the needle tip 112 , the diameter of the needle body 111 , and the real-time diameter of the needle tip 112 .

[0095] Please continue reading Figure 7 and Figure 8 In this embodiment, the real-time length of the needle tip 112 when it is worn to a certain state can be calculated based on the size parameters determined by the first needle pressure adjustment parameter and the second needle pressure adjustment parameter. Figure 3 Available,

[0096] (3)

[0097] (4)

[0098] After obtaining the real-time length of the probe tip 112 when it is worn to a certain state, the needle pressure adjustment amount of the probe can be calculated by combining formula (2) and formula (4) and substituting it into formula (2), as shown in the following formula:

[0099] (5)

[0100] Wherein, L0 is the initial length of the needle tip 112, D bar is the diameter of the probe needle body 111, D1 tip is the real-time diameter of the probe tip 112, D0 tip is the initial diameter of the probe tip 112 .

[0101] Through the above steps, the needle tip 112 is worn to the real-time length of the first needle pressure adjustment parameter in a certain state, and the initial length of the needle tip 112 and the incident angle of the needle tip 112 are used as the second needle pressure adjustment parameter, so that the real-time parameters of the probe needle tip 112 are combined with the historical parameters of the probe to automatically adjust the needle pressure of the probe, thereby improving the accuracy of the needle pressure adjustment.

[0102] Furthermore, by using the real-time length of the needle tip 112 at a certain wear state as the first needle pressure adjustment parameter, real-time length detection can more quickly respond to the wear state of the needle tip 112, thereby improving the sensitivity of needle pressure adjustment. Furthermore, the real-time length change of the needle tip 112 is less affected by system errors, allowing for more accurate needle pressure adjustment to suit the current wear state, further enhancing measurement accuracy.

[0103] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0104] Based on the same inventive concept, embodiments of the present application also provide a wafer acceptance test system, comprising a wafer to be tested, a probe station, and the automatic probe needle pressure control device described in any of the above embodiments. The solution provided by the automatic probe needle pressure control device is the same as the solution described in the automatic probe needle pressure control device in the above embodiments, and will not be repeated here.

[0105] In this embodiment, the probe station may include a platform, a probe card 11, a control system, and a data acquisition system. The probe card 11 is equipped with a plurality of fine probes for contacting test points on a wafer to be tested through probe pads to perform relevant tests.

[0106] The wafer to be tested can be placed on the platform of the probe station, on which probe pads are provided. The control system on the probe station establishes electrical contact by actuating the probes to press against multiple probe pads on the wafer on the wafer table, thereby allowing signals and data to be transmitted during testing.

[0107] During the test, the needle tip 112 on the probe card 11 can movably contact the probe pad on the wafer to be tested, and the probe on the probe station is automatically adjusted by the probe needle pressure automatic control device to perform wafer acceptance testing on the wafer to be tested based on the adjusted needle pressure.

[0108] The above-mentioned wafer acceptance test system calculates the needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter of the probe through the control device 13, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount. Since the first needle pressure adjustment parameter includes the real-time parameter of the needle tip 112, and the second needle pressure adjustment parameter includes the historical parameter of the needle tip 112, the historical parameter includes the parameters of the needle tip 112 before leaving the factory and during use. Therefore, during the use of the probe, not only can the position of the needle tip 112 be timely and automatically corrected according to its real-time parameter, thereby avoiding the influence of poor contact caused by probe wear, but also, considering that the suppliers, preparation processes, and balanced contact force (BCF) of the needle tips 112 of different probes are different, and the parameters before leaving the factory and during use are not the same, the real-time parameters of the probe needle tip 112 are combined with the historical parameters of the probe to automatically adjust the needle pressure of the probe during the needle pressure adjustment, thereby improving the accuracy of the needle pressure adjustment and further ensuring the stability of the test of the wafer to be tested and the reliability of the data.

[0109] Those skilled in the art will understand that the structure shown in the figure is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the wafer acceptance test system to which the solution of the present application is applied. The specific wafer acceptance test system may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0110] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0111] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A probe needle pressure automatic control device, characterized in that: include: an image processing device, configured to obtain a first needle pressure adjustment parameter of the probe, wherein the first needle pressure adjustment parameter includes a real-time parameter of the needle tip of the probe; and a control device for obtaining a second needle pressure adjustment parameter of the probe, calculating a needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, and adjusting the needle pressure of the probe according to the needle pressure adjustment amount; The needle pressure adjustment amount is the vertical height difference between the current position and the ideal position of the probe pad on the wafer to be tested when the needle tip contacts the probe pad on the wafer to be tested; the second needle pressure adjustment parameter includes the historical parameters of the needle tip, and the historical parameters include the parameters of the needle tip before leaving the factory and during use; The control device is specifically used for: Obtain the initial length of the needle tip and the incident angle of the needle tip; Determine the real-time length of the probe tip when it is worn to a certain state; The needle pressure adjustment amount of the probe is determined based on the real-time length of the needle tip when it is worn to a certain state, the initial length of the needle tip, the incident angle of the needle tip, and the relationship between similar triangles, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

2. The probe needle pressure automatic control device according to claim 1, characterized in that: The first needle pressure adjustment parameter includes the real-time diameter of the needle tip, and the second needle pressure adjustment parameter includes the historical diameter of the needle tip. The control device is specifically configured to: Obtaining the real-time diameter and the historical diameter of the needle tip of the probe, and determining the needle diameter change according to the real-time diameter and the historical diameter; A needle pressure adjustment amount of the probe is determined based on the needle diameter change amount, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

3. The probe needle pressure automatic control device according to claim 2, characterized in that: The determining of the needle pressure adjustment amount based on the needle diameter change includes: When the needle diameter change is greater than or equal to a preset needle diameter change threshold, determining the needle pressure adjustment amount according to the preset step amount; When the needle diameter change is less than a preset needle diameter change threshold, no needle pressure adjustment is performed.

4. The probe needle pressure automatic control device according to claim 3, characterized in that: Determining the needle pressure adjustment amount according to the preset step amount includes at least one of the following: Determine the needle pressure adjustment amount according to the preset step amount; A needle pressure adjustment coefficient is determined according to the real-time diameter and the historical diameter of the needle tip of the probe, and a needle pressure adjustment amount is determined based on the needle pressure adjustment coefficient.

5. The probe needle pressure automatic control device according to claim 4, characterized in that: The needle pressure adjustment coefficient is calculated by the following formula: δ=(D 1 tip -D 0 tip ) / D 1 tip in, δ is the needle pressure adjustment coefficient, D 1 tip is the real-time diameter of the probe tip, D 0 tip is the initial diameter of the probe tip.

6. The probe needle pressure automatic control device according to claim 1, characterized in that: Determining the real-time length of the probe tip when it is worn to a certain state includes at least one of the following: receiving a real-time length of the needle tip when it is worn to a certain state obtained by an image processing device; The real-time length of the needle tip when it is worn to a certain state is determined according to the size parameters of the needle tip before and after wear, and the size parameters of the needle tip before and after wear are determined by the first needle pressure adjustment parameter and the second needle pressure adjustment parameter.

7. The probe needle pressure automatic control device according to claim 6, characterized in that: The determining of the real-time length of the needle tip when it is worn to a certain state according to the dimensional parameters of the needle tip before and after wear includes: Obtaining the real-time diameter of the needle tip when it is worn to a certain state; The real-time length of the needle tip when it is worn to a certain state is calculated based on the initial length of the needle tip, the initial diameter of the needle tip, the diameter of the needle body, and the real-time diameter of the needle tip.

8. The probe needle pressure automatic control device according to any one of claims 1 to 7, characterized in that: The control device is further configured to: When the first needle pressure adjustment parameter exceeds a preset wear threshold, an alarm is issued.

9. A wafer acceptance test system, characterized in that: It includes a wafer to be tested, a probe station and a probe needle pressure automatic control device as described in any one of claims 1 to 8, wherein a probe pad is provided on the wafer to be tested, and the probe station is provided with a probe card, and the probes on the probe card can movably contact the probe pads on the wafer to be tested to perform a wafer acceptance test on the wafer to be tested based on the adjusted needle pressure.

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