Probe pressure automatic control device and wafer acceptance test system

Abstract

The invention relates to an automatic probe pressure control device and a wafer acceptance test system, and the device comprises an image processing device which is used for obtaining a first probe pressure adjustment parameter of a probe, and the first probe pressure adjustment parameter comprises a real-time parameter of a probe tip of the probe; the control device is used for acquiring a second probe pressure adjusting parameter of the probe, calculating the probe pressure adjusting amount of the probe based on the first probe pressure adjusting parameter and the second probe pressure adjusting parameter, and adjusting the probe pressure of the probe according to the probe pressure adjusting amount; wherein the second needle pressure adjusting parameters comprise historical parameters of the needle tip, and the historical parameters comprise parameters of the needle tip in the factory leaving and using processes. According to the invention, the accuracy of pin pressure adjustment is improved, and the wafer / chip test stability and data reliability are further ensured.

Description

Technical Field

[0001] The present application relates to the field of semiconductor testing technology, and in particular to an automatic probe needle pressure 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 the friction between the probe tip and the probe pad metal. This wear may cause some of the following effects: (1) Poor contact: Worn probes may not provide good contact, resulting in reduced signal transmission quality, which may lead to inaccurate measurement results or test failures. (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 in order to solve the above technical problems.

[0005] In a first aspect, the present application provides a probe needle pressure automatic control device, comprising: an image processing device, used to obtain 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, used to obtain a second needle pressure adjustment parameter of the probe, calculate the needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, and adjust the needle pressure of the probe according to the needle pressure adjustment amount; 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.

[0006] 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.

[0007] 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 used to: Acquiring the real-time diameter and the historical diameter of the needle tip of the probe, and determining the needle diameter change amount 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 that the needle pressure of the probe is adjusted according to the needle pressure adjustment amount.

[0008] In some embodiments, determining 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, the needle pressure is not adjusted.

[0009] In some embodiments, 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.

[0010] In some embodiments, the needle pressure adjustment coefficient is calculated by the following formula: δ = (D1 tip -D0 tip ) / D1 tip 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.

[0011] In some embodiments, the control device is specifically used to: 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 by calculation according to 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.

[0012] In some embodiments, determining the real-time length of the probe tip when it is worn to a certain state comprises at least one of the following: receiving the real-time length of the needle tip when it is worn to a certain state obtained by the 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.

[0013] In some embodiments, determining the real-time length of the needle tip when it is worn to a certain state according to the size parameters of the needle tip before and after wear, comprises: 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.

[0014] In some embodiments, the control device is further used to issue an alarm when the first needle pressure adjustment parameter exceeds a preset wear level threshold.

[0015] In 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.

[0016] 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 parameter of the needle tip, and the second needle pressure adjustment parameter includes the historical parameter of the needle tip, and the historical parameter includes the parameter of the needle tip when leaving the factory and in 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 parameter to avoid 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 when leaving the factory and in 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 reliable data. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a probe needle pressure automatic control device in one embodiment; Figure 2 A schematic diagram of a probe being inserted into a probe pad on a wafer to be tested in one embodiment; Figure 3A schematic diagram of the structure of a probe in one embodiment; Figure 4 A schematic diagram of the probe needle pressure before and after adjustment in one embodiment; Figure 5 It is a schematic diagram of an acupressure OD automatic control setting interface in one embodiment; Figure 6 is a flow chart of automatic acupressure control in one embodiment; Figure 7 is a schematic diagram of a cross-sectional structure of a probe before needle pressure adjustment in one embodiment; Figure 8 is a schematic diagram of a cross-sectional structure of a probe after needle pressure adjustment in one embodiment; Fig. 9 It is a schematic diagram of the acupressure OD automatic control setting interface in another embodiment. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] Many different embodiments or examples for realizing the different features of the present application are provided below. Specific examples of components and configurations are described below to simplify the present application. Of course, these are only examples and do not limit the scope of the present application. For example, in the following description, 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 additional features are 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.

[0020] The probe station is a precision device used for testing and analyzing semiconductor devices. It is widely used in integrated circuit manufacturing, research and development, and failure analysis. The probe station usually 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, which are used to contact the test points on the wafer through the probe pads to perform relevant tests.

[0021] The present application provides a probe needle pressure automatic control device, which can be integrated into the above-mentioned probe station as a part of the probe station. The probe needle pressure automatic control device can obtain and monitor the adjustment parameters of the probe in real time, calculate the needle pressure adjustment amount of the probe, analyze and adjust according to the needle pressure adjustment amount, and ensure that the probe is always kept within the optimal needle pressure range during the test process.

[0022] By controlling the needle pressure of the probe, the accurate position of the probe is ensured, thereby ensuring good contact between the probe and the test point for transmission and measurement of electrical signals. The automatic control device of the needle pressure of the probe can improve the accuracy and reliability of the test, reduce human intervention, and improve production efficiency and product quality.

[0023] In this embodiment, the probe needle pressure automatic control device includes: an image processing device 12 and a control device 13. Among them: 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. 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 wear degree of the needle tip 112 of the probe continues to increase, affecting the test effect.

[0024] 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 requirements and accuracy requirements, and the present 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.

[0025] Exemplarily, the probe tip 112 may be placed within the field of view of the image processing device 12, the focus may be adjusted to obtain a clear image, and then the edge of the tip 112 may be automatically identified by an edge detection algorithm and the diameter thereof may be obtained.

[0026] 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, and the historical parameters include the parameters of the needle tip 112 before leaving the factory and during use. It can be understood that the parameters of the needle tip 112 before leaving the factory are the initial parameters of the needle tip 112, which can be 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. Correspondingly, the parameters of the needle tip 112 during use are the size and angle parameters of the needle tip 112 when it is worn to a certain state during use.

[0027] 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.

[0028] 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.

[0029] 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 multivariable needle pressure empirical formula or calibration curve related to the first needle pressure adjustment parameter and the second needle pressure adjustment parameter is combined to obtain the corresponding needle pressure adjustment amount. 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.

[0030] 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 parameter of the needle tip 112 when 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 to avoid 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 when leaving the factory and during use are not the same, when adjusting the needle pressure, 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 and further ensuring the stability of wafer / chip testing and the reliability of data.

[0031] 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.

[0032] 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 amount according to the real-time diameter and the historical diameter.

[0033] 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.

[0034] 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 can be understood that the needle diameter change amount can 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 amount can be the change amount between the real-time diameter of the needle tip 112 and the initial diameter of the needle tip 112, or it can be the change amount between the current real-time diameter of the needle tip 112 and the real-time diameter obtained by the last measurement of the needle tip 112. By using the needle diameter change amount as the key parameter for controlling the needle pressure, the needle pressure can be controlled in real time according to the change of the needle diameter, so that the probe can obtain the best contact effect.

[0035] Step S12, determining a needle pressure adjustment amount of the probe based on the needle diameter change amount, so as to adjust the needle pressure of the probe according to the needle pressure adjustment amount.

[0036] 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. At this time, 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 the complexity and adjustment time of the system are reduced.

[0037] For example, the probe needle pressure OD automatic control setting interface is as follows Figure 5As shown, when OD is automatically adjusted to YES, it means that the needle pressure automatic control function is turned on, and when OD is automatically adjusted to 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 configuration of components.

[0038] The flowchart of automatic control of acupuncture pressure by the probe acupuncture pressure automatic control device is as follows Figure 6 shown.

[0039] Step S1, turning on the automatic acupressure control function; Step S2, setting 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.

[0040] 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; 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; 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 according to the real-time diameter and the historical diameter; Step 6, step S6.1, when the needle diameter change delta is greater than or equal to the preset needle diameter change threshold, the needle pressure adjustment amount OD is determined according to the preset step amount; step S6.2, otherwise, the OD adjustment is not triggered; 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; Step S8, start the acupuncture test.

[0041] Specifically, in some embodiments, determining the needle pressure adjustment amount according to the preset step amount may be determining the needle pressure adjustment amount according to the preset step amount, that is, when the needle pressure adjustment is triggered, the needle pressure adjustment is performed according to the preset step length.

[0042] In other embodiments, the needle pressure adjustment amount is determined according to the preset step amount, and the needle pressure adjustment coefficient can be determined according to the real-time diameter and the 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 adjustment step length of the needle pressure is not fixed, and the degree of wear affects the step length of the needle pressure adjustment. The needle pressure adjustment coefficient is determined according to the real-time diameter and the 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.

[0043] In this embodiment, when the degree of wear of the probe needle tip 112 is higher, the contact stability is worse. At this time, the adjustment step size can be increased to increase the needle pressure adjustment coefficient so that the needle tip 112 and the probe pad are in stable contact. For example, the needle pressure adjustment coefficient is calculated by the following formula: δ = (D1 tip -D0 tip ) / D1 tip (1) 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 .

[0044] 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 the present application does not limit this.

[0045] 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 level threshold.

[0046] In this embodiment, when the first needle pressure adjustment parameter exceeds the preset wear threshold, it indicates that the wear of the current probe tip 112 has exceeded the maximum allowable standard, and the continued use of the current probe will affect the accuracy of the measurement and cannot be overcome by needle pressure adjustment. At this time, an alarm prompt needs to be pushed to the user. The alarm prompt can remind the operator to replace or calibrate the probe in time to maintain the measurement accuracy.

[0047] In some embodiments, the needle pressure adjustment amount can be calculated in real time according to the size and angle parameters of the probe, and the control device 13 is specifically used to implement the following steps: S21, obtaining the initial length of the needle tip 112 and the incident angle of the needle tip 112.

[0048] S22, determining the real-time length of the needle tip 112 of the probe when it is worn to a certain state.

[0049] S23, calculating and determining the needle pressure adjustment amount of the probe according to the real-time length of the needle tip 112 when 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.

[0050] In this embodiment, the wear of the probe needle tip 112 is not only reflected in the change of diameter, but also affects the length of the needle tip 112. The first needle pressure adjustment parameter includes the real-time length of the needle tip 112 when it is worn to a certain state. The second needle pressure adjustment parameter includes the initial length of the needle tip 112 and the incident angle of the needle tip 112. Among them, the incident angle of the needle tip 112 refers to the angle between the axis of the needle tip 112 and the probe pad (i.e., the horizontal direction). The initial length of the needle tip 112 and the incident angle of the needle tip 112 do not change with the wear of the needle tip 112, and are known constants that can be directly obtained.

[0051] 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, and 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 refer to the relevant description of the image processing device 12 acquiring the first needle pressure adjustment parameter of the probe in the above embodiment, and this application will not repeat it here.

[0052] like Figure 7 and Figure 8 The figure shows a schematic diagram of the cross-sectional structure of the probe before and after the needle pressure is adjusted. After obtaining the real-time length of the needle tip 112 of the probe when it is worn to a certain state, the needle pressure adjustment amount of the probe can be calculated based on the relationship of similar triangles, as shown in the following formula: (2) 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 .

[0053] 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. By using the preset length 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 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 the complexity and adjustment time of the system are reduced.

[0054] For example, the probe needle pressure OD automatic control setting interface is as follows Fig. 9 As shown, when OD automatic adjustment is YES, it indicates that the needle pressure automatic control function is turned on, and when OD automatic adjustment is NO, it indicates that the needle pressure automatic control function is turned off. The 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 degree threshold can be configured by the user.

[0055] 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 size parameters of the needle tip 112 before and after it is worn. The size parameters of the needle tip 112 before and after it is worn are determined by the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, including one or more of the diameter of the needle tip 112, the incident angle of the needle tip 112, 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, the real-time length of the needle tip 112 when it is worn to a certain state based on the size parameters of the needle tip 112 before and after it is worn includes: S221, obtaining the real-time diameter of the needle tip 112 when it is worn to a certain state; S222, calculating the real-time length of the needle tip 112 when it is worn to a certain state according to 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.

[0056] 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, (3) (4) After obtaining the real-time length of the probe tip 112 when it is worn to a certain state, by combining equation (2) and substituting equation (4) into equation (2), the needle pressure adjustment amount of the probe can be calculated and determined, as shown in the following equation: (5) 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 .

[0057] Through the above steps, the real-time length of the needle tip 112 worn to a certain state is used as the first needle pressure adjustment parameter, 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.

[0058] At the same time, by using the real-time length of the needle tip 112 when it is worn to a certain state as the first needle pressure adjustment parameter, since the length change of the needle tip 112 usually more directly affects the contact surface of the contact pad and the measurement method. Real-time length detection can respond to the state of wear of the needle tip 112 more quickly, thereby improving the sensitivity of needle pressure adjustment. In addition, the real-time length change of the needle tip 112 is less affected by the system error, and the needle pressure can be adjusted more accurately to adapt to the current wear state, further improving the accuracy of the measurement.

[0059] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed 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 part of the steps or stages in other steps.

[0060] Based on the same inventive concept, the embodiment of 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 described in any of the above embodiments. The implementation solution provided by the probe needle pressure automatic control device to solve the problem is the same as the implementation solution recorded in the probe needle pressure automatic control device in the above embodiment, and will not be repeated here.

[0061] 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 the test points on the wafer to be tested through the probe pads to perform relevant tests.

[0062] The wafer to be tested can be placed on a platform of a probe station, on which probe pads are arranged. 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 station, thereby allowing signals and data to be transmitted during testing.

[0063] 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 a wafer acceptance test on the wafer to be tested based on the adjusted needle pressure.

[0064] 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, and the historical parameter includes the parameter of the needle tip 112 during the factory and use process, 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 during the factory and use process are not the same, when adjusting the needle pressure, 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 and further ensuring the stability of the test of the wafer to be tested and the reliability of the data.

[0065] Those skilled in the art will understand that the structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the wafer acceptance test system to which the scheme of the present application is applied. The specific wafer acceptance test system may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0066] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and 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 embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium 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), magnetoresistive 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0067] The technical features of the above embodiments may 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.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A probe needle pressure automatic control device, characterized in that: include: An image processing device, used for acquiring a first needle pressure adjustment parameter of the probe, wherein the first needle pressure adjustment parameter includes a real-time parameter of a needle tip of the probe; and a control device, configured to obtain a second needle pressure adjustment parameter of the probe, calculate a needle pressure adjustment amount of the probe based on the first needle pressure adjustment parameter and the second needle pressure adjustment parameter, and adjust the needle pressure of the probe according to the needle pressure adjustment amount; 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.

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, the second needle pressure adjustment parameter includes the historical diameter of the needle tip, and the control device is specifically used for: Acquiring the real-time diameter and the historical diameter of the needle tip of the probe, and determining the needle diameter change amount 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 that the needle pressure of the probe is adjusted according to the needle pressure adjustment amount.

3. The probe needle pressure automatic control device according to claim 2, characterized in that: The step of determining the needle pressure adjustment amount based on the needle diameter change amount 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, the needle pressure is not adjusted.

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=(D1 tip -D0 tip ) / D1 tip 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.

6. The probe needle pressure automatic control device according to claim 1, characterized in that: 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 by calculation according to 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.

7. The probe needle pressure automatic control device according to claim 6, 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 the real-time length of the needle tip when it is worn to a certain state obtained by the 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.

8. The probe needle pressure automatic control device according to claim 7, characterized in that: The step of determining the real-time length of the needle tip when it is worn to a certain state according to the size parameters of the needle tip before and after wear, comprises: 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.

9. The probe needle pressure automatic control device according to any one of claims 1 to 8, characterized in that: The control device is also used to issue an alarm when the first needle pressure adjustment parameter exceeds a preset wear degree threshold.

10. A wafer acceptance test system, characterized in that: It comprises a wafer to be tested, a probe station and an automatic probe needle pressure control device as described in any one of claims 1 to 9, wherein a probe pad is arranged 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 so as to perform a wafer acceptance test on the wafer to be tested based on the adjusted needle pressure.

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