Wafer needle prodding test method and system

Abstract

The application discloses a wafer needle pressure test method and system, the wafer needle pressure test method comprises the following steps: obtaining the overall warping degree of the wafer and the needle pressure data of the wafer, the overall warping degree of the wafer represents the height of the surface of the wafer in contact with the probe; based on the overall warping degree and the needle pressure data of the wafer, the moving distance of the wafer moving towards the probe is controlled to perform needle pressure test on the wafer. The application obtains the overall warping degree of the wafer and the needle pressure data of the wafer, and controls the moving distance of the wafer moving towards the probe based on the overall warping degree and the needle pressure data of the wafer to perform needle pressure test on the wafer, so that the moving distance of each test point of the wafer is different when performing needle pressure test, and the problem of poor contact or piercing the chip metal pin caused by using the same needle pressure value to test the three-dimensional integrated wafer is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer needle pressure testing, in particular to a wafer needle pressure testing method and system. BACKGROUND

[0002] The 3DIC DRAM is a process procedure realized by bonding process of a logic wafer and a storage wafer. In order to achieve the best bonding effect, the logic wafer and the storage wafer have requirements on the warping degree of the wafer, so that the flatness of the DRAM wafer manufactured by 3DIC bonding is poor. At the same time, due to the bonding of the two wafers, the final wafer needs to be thinned, and the thickness consistency of the wafer obtained by the thinning operation is large. In the traditional DRAM wafer test needle pressure determination process, only one needle pressure value is used to realize the needle pressure test of the whole wafer. If the traditional DRAM wafer test needle pressure method is used to test the 3DIC DRAM, contact test problems often occur, such as poor contact between the probe and the wafer, or the problem of the probe piercing the chip metal pin. SUMMARY

[0003] The present application at least provides a wafer needle pressure testing method and system to solve the contact test problem caused by using the traditional DRAM wafer test needle pressure method to test the 3DIC DRAM.

[0004] The first aspect of the present application provides a wafer needle pressure testing method, which comprises:

[0005] obtaining the overall warping degree of the wafer and the needle pressure data of the wafer, the overall warping degree of the wafer representing the height of the surface of the wafer in contact with the probe;

[0006] controlling the moving distance of the wafer moving towards the probe based on the overall warping degree and the needle pressure data of the wafer, so as to perform needle pressure test on the wafer.

[0007] Optionally, the method further comprises:

[0008] controlling the wafer to move towards the probe by a first preset distance, so as to test the needle pressure data of the reference point of the wafer by using the probe; the needle pressure data of the reference point of the wafer is the needle pressure data of the wafer.

[0009] Optionally, the step of controlling the moving distance of the wafer moving towards the probe based on the overall warping degree and the needle pressure data of the wafer, so as to perform needle pressure test on the wafer, comprises:

[0010] in response to the height of the detection point in the surface of the wafer in contact with the probe being greater than the height of the center point of the wafer, controlling the wafer to move towards the probe by a second preset distance, so as to perform needle pressure test on the wafer and obtain a test result;

[0011] In response to the height of the detection point in the surface of the wafer in contact with the probe being less than the height of the center point, the wafer is controlled to move to the probe by a third preset distance to perform a needle pressure test on the wafer to obtain a test result.

[0012] The second preset distance is less than the first preset distance, the third preset distance is greater than the first preset distance, and after the wafer is moved by the second preset distance and / or the third preset distance, the needle pressure data of the detection point matches the needle pressure data of the center point of the wafer.

[0013] Optionally, the method further comprises:

[0014] Comparing the electrical signal in the test result with a preset electrical signal;

[0015] In response to the electrical signal in the test result not matching the preset electrical signal, adjusting the distance by which the wafer moves to the probe based on the needle pressure data in the test result and the needle pressure data of the reference point of the wafer to retest the wafer.

[0016] Optionally, the step of adjusting the distance by which the wafer moves to the probe based on the needle pressure data in the test result and the needle pressure data of the reference point of the wafer comprises:

[0017] Obtaining a standard parameter table; wherein the standard parameter table is used to calibrate the needle pressure data corresponding to different electrical signals generated by the wafer;

[0018] Obtaining first needle pressure data corresponding to the electrical signal in the test result based on the standard parameter table;

[0019] Adjusting the distance by which the wafer moves to the probe based on the first needle pressure data and the needle pressure data of the reference point of the wafer.

[0020] Optionally, the step of adjusting the distance by which the wafer moves to the probe based on the first needle pressure data and the needle pressure data of the reference point of the wafer comprises:

[0021] In response to the first needle pressure data being greater than the needle pressure data of the reference point of the wafer, calculating a first difference value between the first needle pressure data and the needle pressure data of the reference point of the wafer;

[0022] Based on the first difference value, reducing the movement distance of the wafer to the probe, so that the distance difference between the adjusted movement distance and the unadjusted movement distance is equal to the first difference value;

[0023] In response to the first needle pressure data being less than the needle pressure data of the reference point of the wafer, calculating a second difference value between the needle pressure data of the reference point of the wafer and the first needle pressure data;

[0024] Based on the second difference value, increasing the movement distance of the wafer to the probe, so that the distance difference between the adjusted movement distance and the unadjusted movement distance is equal to the second difference value.

[0025] Optionally, the step of obtaining the overall warpage of the wafer includes:

[0026] A scan is performed from the center point of the wafer to the edge region of the wafer to obtain at least one scan trajectory that moves in a straight line from the center point of the wafer to the edge region of the wafer; wherein the scan trajectory includes multiple probe points, and the distance between two adjacent probe points within the same scan trajectory is equal;

[0027] Obtain the height difference between each probe point of at least one scan trajectory and the center point of the wafer;

[0028] By fitting the height difference between all probe points and the center point of the wafer, the overall warpage of the wafer is obtained.

[0029] A second aspect of this application provides a wafer pin pressure testing system, the wafer pin pressure testing system comprising:

[0030] A support platform is used to support wafers;

[0031] The probe is positioned on the side of the wafer away from the support stage and is used to perform needle pressure testing on the wafer.

[0032] A recording device is used to acquire the overall warpage of a wafer, which characterizes the height of the surface of the wafer in contact with the probe.

[0033] The control device, connected to the recording device and the carrier stage, is used to acquire the needle pressure data of the wafer and control the movement of the carrier stage based on the overall warpage and the needle pressure data of the wafer, so as to control the moving distance of the wafer towards the probe.

[0034] Optionally, the wafer pin pressure testing system also includes:

[0035] An adjustment stage, set on a support platform, is used to attach and fix the wafer; wherein the center of the adjustment stage coincides with the center of the support platform in a direction perpendicular to the support platform;

[0036] A scanning device, one end of which is mounted on a support platform and the other end is movably mounted on the side of the wafer away from the support platform, is used to scan the wafer to obtain scanning results;

[0037] The recording device is further connected to the scanning device, and the overall warpage of the wafer is calculated based on the scanning results.

[0038] Optionally, the wafer pin pressure testing system also includes:

[0039] A collection device, connected to a probe, is used to collect the test results of needle pressure testing on wafers;

[0040] The testing device connects the data collection device and the control device, and is used to compare the electrical signal in the test result with a preset electrical signal.

[0041] In response to a mismatch between the electrical signal in the test results and the preset electrical signal, the control device is also used to adjust the distance the wafer moves toward the probe based on the needle pressure data in the test results and the needle pressure data of the wafer's reference point, so as to retest the wafer.

[0042] The beneficial effects of this application are as follows: Unlike the prior art, this application obtains the overall warpage and pin pressure data of the wafer, and controls the moving distance of the wafer towards the probe based on the overall warpage and pin pressure data to perform pin pressure testing on the wafer. This makes the moving distance of each test point on the wafer different during pin pressure testing, avoiding the problem of poor contact or puncturing the chip metal pins caused by using the same pin pressure value to test the three-dimensional integrated wafer.

[0043] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a first structural schematic diagram of an embodiment of the wafer pin pressure testing system of this application;

[0046] Figure 2 This is a second structural schematic diagram of an embodiment of the wafer pin pressure testing system of this application;

[0047] Figure 3 This is a schematic flowchart of an embodiment of the wafer pin pressure testing method of this application;

[0048] Figure 4 yes Figure 3 A detailed flowchart of step S11 is shown below;

[0049] Figure 5 yes Figure 3 A detailed flowchart of step S12 is shown below;

[0050] Figure 6 yes Figure 3 A schematic diagram of the specific process after step S12;

[0051] Figure 7 yes Figure 6 A detailed flowchart of step S14 is shown below;

[0052] Figure 8 yes Figure 7 A detailed flowchart of the first embodiment of step S143;

[0053] Figure 9 yes Figure 7 A detailed flowchart of the second embodiment of step S143. Detailed Implementation

[0054] To enable those skilled in the art to better understand the technical solutions of this application, the wafer pin pressure testing method and system provided in this application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It is understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0055] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0056] This application provides a wafer pin pressure testing method to solve the problems of poor probe contact with the wafer or probe puncturing the chip's metal pins that occur when testing 3DIC DRAM using traditional DRAM wafer pin pressure testing methods. Please refer to... Figure 3 , Figure 3 This is a schematic flowchart of an embodiment of the wafer pin pressure testing method of this application.

[0057] The wafer pin pressure testing method of this application can be implemented by a wafer pin pressure testing system, specifically as follows: Figure 1 and Figure 2 As shown. Please refer to [the original text]. Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the wafer pin pressure testing system of this application. Figure 2 This is a second structural schematic diagram of an embodiment of the wafer pin pressure testing system of this application.

[0058] like Figure 1 As shown, the wafer pin pressure testing system 20 includes a stage 21, a probe 22, a scanning device 23, a recording device 24, a control device 25, a collecting device 26, and a testing device 27. The stage 21 is used to support the wafer 30.

[0059] Specifically, probe 22 is positioned on the side of wafer 30 facing away from stage 21. One end of scanning device 23 is mounted on stage 21, and the other end is movably positioned on the side of wafer 30 facing away from stage 21. Recording device 24 is connected to scanning device 23, control device 25 is connected to recording device 24 and stage 21, collection device 26 is connected to probe 22, and testing device 27 is connected to collection device 26 and control device 25. Optionally, both scanning device 23 and stage 21 are movable devices. Scanning device 23 can be moved above wafer 30 as needed, or stage 21 can be moved to bring wafer 30 into contact with probe 22 for appropriate operations.

[0060] In this system, probe 22 is used to perform pin pressure testing on wafer 30, scanning device 23 is used to scan wafer 30 to obtain scanning results, and recording device 24 is used to calculate the overall warpage of wafer 30 based on the scanning results. The overall warpage of wafer 30 characterizes the height of the surface of wafer 30 in contact with probe 22. Unlike existing wafer pin pressure testing systems that use the same pin pressure to test the wafer under test and do not adjust the test according to the different curvatures of 3DIC DRAM, the wafer pin pressure testing system 20 in this embodiment can obtain the overall warpage of wafer 30 through scanning device 23 and effectively adjust the corresponding pin pressure value.

[0061] The control device 25 acquires pin pressure data of the wafer 30 and controls the movement of the support stage 21 based on the overall warpage and the pin pressure data of the wafer 30 to control the movement distance of the wafer 30 towards the probe 22, thereby performing a pin pressure test on the wafer 30. The collection device 26 collects the test results of the pin pressure test on the wafer 30, including pin pressure results and pin mark results. The testing device 27 compares the electrical signal in the test results with a preset electrical signal; in response to a mismatch between the electrical signal in the test results and the preset electrical signal, the control device 25 further adjusts the movement distance of the wafer 30 towards the probe 22 based on the pin pressure data in the test results and the pin pressure data of a reference point on the wafer 30, thereby retesting the wafer 30.

[0062] Because wafer 30 has poor flatness, further fixation of wafer 30 is required. For example... Figure 2As shown, the wafer pin pressure testing system 20 of this embodiment may further include an adjustment platform 28 disposed on the support stage 21, wherein the adjustment platform 28 is a curved adjustable structure used to fit and fix the wafer 30. When the wafer 30 is placed on the adjustment platform 28, the adjustment platform 28 automatically adjusts its own structure according to the surface curvature of the wafer 30, so that the adjustment platform 28 fits tightly with the wafer 30, thereby effectively fixing the wafer 30. At the same time, due to the self-adjusting structure of the adjustment platform, the adjustment platform 28 is suitable for various wafers, making it convenient for the wafer pin pressure testing system 20 to perform pin pressure testing on wafers of different sizes or thicknesses. This differs from the prior art in which the wafer under test is positioned by a fixed fixing structure, thus improving the applicability of the wafer pin pressure testing system 20 of this embodiment.

[0063] Optionally, in this embodiment, the center of the adjustment platform 28 and the center of the support platform 21 coincide in a direction perpendicular to the support platform 21, so that when the wafer 30 is fixed on the adjustment platform 28, the center of the wafer 30, the center of the adjustment platform 28, and the center of the support platform 21 all coincide in a direction perpendicular to the support platform 21.

[0064] Optionally, the control device 25 includes a first control device 251 and a second control device 252. The first control device 251 is connected to the recording device 24 and the testing device 27, and the second control device 252 is connected to the first control device 251 and the support stage 21. The first control device 251 calculates the moving distance of the support stage 21 based on the overall warpage of the wafer 30 and the needle pressure data of the wafer 30, and transmits the calculated moving distance to the second control device 252. The second control device 252 controls the support stage 21 to move a corresponding distance according to this moving distance. Simultaneously, the second control device 252 also adjusts the moving distance of the support stage 21 based on the judgment result of the testing device 27.

[0065] Optionally, in this embodiment, the collecting device 26 may include a needle pressure collecting device and a needle mark collecting device. The needle pressure collecting device may be a testing device electrically connected to the probe 22, which collects needle pressure results by receiving electrical signals generated when the probe 22 contacts the wafer 30, including at least one of voltage, current, and the distance between the wafer 30 and the probe 22. The needle mark collecting device may be an image processor, which collects needle mark results by capturing images of the needle marks and extracting image features, including at least one of length, width, depth, and distance from the center of the metal pins of the wafer 30.

[0066] This application also provides a wafer pin pressure testing method; please refer to [link / reference]. Figure 3 , Figure 3 This is a schematic flowchart of an embodiment of the wafer pin pressure testing method of this application. The main body executing this wafer pin pressure testing method can be the wafer pin pressure testing system 20 described in the above embodiment. Specifically, as... Figure 3As shown, the wafer pin pressure testing method of this application may include the following steps:

[0067] Step S11: Obtain the overall warpage of the wafer and the needle pressure data of the wafer.

[0068] In this embodiment, the wafer 30 to be tested is a 3DIC wafer, which has poor flatness and large thickness consistency deviation. Therefore, it is necessary to obtain the overall warpage of the wafer 30 to be tested.

[0069] Specifically, in this embodiment, the wafer 30 is placed on the support stage 21 beforehand, and the overall warpage of the wafer 30 is obtained by scanning the wafer 30. In this embodiment, the overall warpage of the wafer 30 is obtained by scanning the wafer 30 using a scanning device 23.

[0070] Furthermore, the wafer needle pressure testing system 20 controls the movement of the support stage 21 to move the wafer 30 until the probe 22 is inserted into the wafer 30. Therefore, it is necessary to determine the depth of the probe 22 inserted into the wafer 30, that is, to determine the needle pressure data of the wafer 30.

[0071] In this embodiment, the wafer needle pressure testing system 20 is pre-set with a preset needle pressure value corresponding to a reference point. The preset needle pressure value is the needle pressure value that can obtain the optimal data when the needle pressure test is performed at the center point of the wafer 30.

[0072] Optionally, depending on the type and model of the wafer 30, the relevant test personnel can set a first preset distance based on experience. Specifically, the first preset distance is the distance from which the tip of the probe 22 moves to the center test point, and the center test point coincides with the center point of the wafer 30 in a direction perpendicular to the support stage 21. Optionally, the center test point can be a test point set by the relevant test personnel based on experience, that is, the depth to which the tip of the probe 22 needs to penetrate downwards from the center point of the wafer 30 in a direction perpendicular to the support stage 21, as determined by the relevant test personnel based on experience.

[0073] Specifically, in this embodiment, the reference point of wafer 30 is the center point of wafer 30. The second control device 252 controls the stage 21 to move according to the initial needle pressure value, thereby controlling wafer 30 to move a first preset distance towards probe 22, so as to use probe 22 to test the needle pressure data of the reference point of wafer 30. When the reference point of wafer 30 and the probe come into contact, the needle pressure test generates an electrical signal and a needle mark due to the contact between probe 22 and wafer 30. After the needle pressure test is completed, the second control device 252 controls probe 22 to move back to the initial position, and the collection device 26 obtains the preliminary test results based on the electrical signal and needle mark. The preliminary test results include the test electrical signal and the test needle mark.

[0074] Furthermore, this embodiment has a preset threshold range for judging the quality of needle pressure test results. The testing device 27 obtains the preset threshold range and the pre-test results collected by the collecting device 26, and further judges whether the pre-test results are within the preset threshold range.

[0075] Specifically, the preset threshold range may include voltage threshold range, current threshold range, length threshold range, width threshold range, depth threshold range, and distance threshold range from the center of the metal pins of the wafer 30. The corresponding preset threshold range is selected according to the data type of the pre-test results.

[0076] If the pre-test result is within the preset threshold range, it proves that the result of the test item performed at the center point meets the expected requirements. If the pre-test result is not within the preset threshold range, it proves that the result of the test item performed at the center test point does not meet the expected requirements. It is necessary to adjust the first preset distance, that is, adjust the moving distance of the carrier stage 21, in order to adjust the state of the probe 22 inserted into the wafer 30. Specifically, it may include the depth of insertion into the wafer 30, until the pre-test result is within the preset threshold range.

[0077] Therefore, when the pre-test result is within the preset threshold range, the needle pressure data of the reference point corresponding to the pre-test result can be obtained according to the first preset distance. That is, the optimal depth at which the probe 22 is inserted into the wafer 30 at the reference point is the needle pressure data of the reference point and the needle pressure data of the wafer 30.

[0078] Optionally, the specific process for obtaining the overall warpage of the wafer can be as follows: Figure 4 Please refer to the process shown below. Figure 4 , Figure 4 yes Figure 3 A detailed flowchart of step S11 is provided. Specifically, it includes the following steps:

[0079] Step S111: Scan from the center point of the wafer to the edge region of the wafer to obtain at least one scan trajectory that moves in a straight line from the center point of the wafer to the edge region of the wafer.

[0080] The scanning device 23 starts scanning from the center point of the wafer 30, so the center point of the wafer 30 needs to be set. Optionally, in this embodiment, the tray for fixing the wafer 30 is set at the exact center of the support stage 21 so that when the wafer 30 is placed on the tray, it is automatically positioned at the exact center of the support stage 21.

[0081] Simultaneously, the scanning device 23 also needs to set a scanning direction. Specifically, since the wafer 30 is circular, the edge region of the wafer 30 is the outer circumference region, and the outer circumference region includes multiple regions. Therefore, the first direction from the center point of the wafer to the edge region of the wafer is set as the scanning direction of the scanning device 23. The scanning device 23 needs to perform multiple scans from the center point of the wafer 30 to the edge region of the wafer 30 to obtain multiple scan data.

[0082] The scanning device 23 moves linearly from the center point of the wafer 30 to the edge region of the wafer 30 at the same speed, forming at least one scanning trajectory. Specifically, one scanning trajectory corresponds to one scan performed by the scanning device 23 from the center point of the wafer 30 to the edge region of the wafer 30.

[0083] The scanning trajectory includes multiple detection points, and the distance between any two adjacent detection points within the same scanning trajectory is equal. Specifically, wafer 30 can consist of multiple rectangular regions of the same size, with each rectangular region corresponding to one detection point, thus wafer 30 can be considered to include multiple detection points. Since the multiple rectangular regions are of the same size, it can be determined that the distance between the detection points corresponding to adjacent rectangular regions is equal.

[0084] Specifically, during the process of the scanning device 23 moving in a straight line from the center point of the wafer 30 to the edge region of the wafer 30, it passes through multiple adjacent rectangular regions. That is, the same scanning trajectory includes multiple sequentially adjacent detection points. Therefore, the distance between two adjacent detection points on the same scanning trajectory is equal.

[0085] Optionally, the scanning device 23 can move at a speed of 1 micrometer / second, and for every micrometer it moves, the scanning device 23 scans the wafer 30 once and acquires data of the detection point once, that is, the scanning frequency of the scanning device 23 is 1 time / second.

[0086] Step S112: Obtain the height difference between each probe point of at least one scan trajectory and the center point of the wafer.

[0087] In this embodiment, the center point of wafer 30 is used as the reference point. Therefore, the height of the center point of wafer 30 is used as the reference height to calculate the height difference between each detection point on multiple scanning trajectories and the reference height.

[0088] Specifically, in this embodiment, the height corresponding to the center point of wafer 30 is set as the reference height, that is, the center point of wafer 30 is 0 micrometers. When scanning other test points, if the height corresponding to the probe point is greater than the height corresponding to the center point of wafer 30, the height corresponding to the probe point is positive; if the height corresponding to the probe point is less than the height corresponding to the center point of wafer 30, the height corresponding to the probe point is negative.

[0089] In this embodiment, based on at least one scanning trajectory obtained in step S111, the heights corresponding to multiple detection points of wafer 30 can be obtained. Furthermore, the height difference between the height corresponding to each detection point and the reference height can be calculated by the recording device 24 to obtain multiple height differences.

[0090] Step S113: Fit the height difference between all probe points and the center point of the wafer to obtain the overall warpage of the wafer.

[0091] The recording device 24 further performs fitting processing on multiple height differences to obtain the overall warpage of the wafer 30. Optionally, the recording device 24 can store multiple fitting formulas, select the appropriate fitting formula according to actual needs, perform fitting processing on multiple height differences to obtain a fitting curve, which can calibrate the overall warpage of the wafer 30. The overall warpage of the wafer 30 is used to characterize the height of the surface of the wafer 30 in contact with the probe 20.

[0092] Step S12: Based on the overall warpage and the wafer's needle pressure data, control the distance the wafer moves toward the probe to perform needle pressure testing on the wafer.

[0093] The first control device 251 calculates the moving distance of the carrier stage 21 based on the overall warpage of the wafer 30 and the needle pressure data of the wafer 30, and transmits the calculated moving distance to the second control device 252. The second control device 252 controls the carrier stage 21 to move the corresponding distance according to the moving distance in order to perform needle pressure test on the wafer 30.

[0094] Specifically, the first control device 251 obtains the overall warpage of the wafer 30 according to step S113, and knows the height difference between multiple detection points and the center point of the wafer 30. Based on the reference point of the wafer 30, i.e. the center point of the wafer 30, the first preset distance for needle pressure testing can be calculated to obtain the corresponding distance that different detection points need to move for needle pressure testing. Specifically, the sum of the height difference and the first preset distance can be calculated.

[0095] Among the multiple height differences, there are positive and negative values. When calculating the sum of the height difference and the first preset distance, if the height difference is positive, it is the first preset distance minus the height difference; if the height difference is negative, it is the first preset distance plus the height difference. The calculated value is the distance that the probe 22 needs to move when the corresponding probe point is subjected to needle pressure testing, that is, the distance that the support stage 21 needs to move.

[0096] Specifically, the support platform 21 can move along a first direction, a second direction, or a third direction. The first direction is perpendicular to the second direction and the third direction, respectively, and the second direction is perpendicular to the third direction. Among them, the first direction and the third direction are two directions parallel to the plane of the support platform 21, which are also the X and Y directions in the Earth coordinate system; the second direction is a direction perpendicular to the support platform 21, which is also the Z direction in the Earth coordinate system.

[0097] Optionally, since the spacing between adjacent detection points is the same, the distance between the corresponding detection pilot point and the center point of the wafer 30 can be determined, which is the required movement distance of the support stage 21 in the first direction and / or the third direction. At the same time, the required movement distance of the support stage 21 in the second direction can be determined according to the overall warpage of the wafer 30. By combining the two, the specific movement distance of the support stage 21 when the characteristic detection point is subjected to needle pressure test can be obtained.

[0098] Optionally, the process of controlling the movement distance of the wafer towards the probe based on the overall warpage and the wafer's probe pressure data can be as follows: Figure 5 Please refer to the process shown below. Figure 5 , Figure 5 yes Figure 3 A detailed flowchart of step S12 is provided. Specifically, it includes the following steps:

[0099] Step S121: In response to the fact that the height of the probe point on the surface in contact with the probe is greater than the height of the center point of the wafer, control the wafer to move a second preset distance toward the probe to perform a needle pressure test on the wafer and obtain the test result.

[0100] In response to the fact that the height of the detection point on the surface where the wafer 30 contacts the probe 22 is greater than the height of the center point of the wafer 30, i.e. the height difference between the detection point and the center point is positive, the wafer is controlled to move towards the probe by a second preset distance, i.e. the difference between the first preset distance and the height difference, so as to perform a needle pressure test on the wafer and obtain the test result.

[0101] Wherein, the second preset distance is less than the first preset distance, and after moving the second preset distance, the needle pressure data of the probe point matches the needle pressure data of the center point of the wafer.

[0102] Step S122: In response to the fact that the height of the probe point on the surface in contact with the probe is less than the height of the center point of the wafer, control the wafer to move towards the probe by a third preset distance to perform a needle pressure test on the wafer and obtain the test result.

[0103] In response to the fact that the height of the detection point on the surface where the wafer 30 contacts the probe 22 is less than the height of the center point of the wafer 30, i.e. the height difference between the detection point and the center point is negative, the wafer is controlled to move towards the probe by a second preset distance, i.e. the sum of the first preset distance and the height difference, so as to perform a needle pressure test on the wafer and obtain the test result.

[0104] Among them, the third preset distance is greater than the first preset distance, and after moving the third preset distance, the needle pressure data of the detection point matches the needle pressure data of the center point of the wafer 30.

[0105] After completing step S12, the following can also be performed: Figure 6 Please refer to steps S13 and S14 as shown. Figure 6 , Figure 6 yes Figure 3 A flowchart illustrating the process after step S12. Specifically, it includes the following steps:

[0106] Step S13: Compare the electrical signal in the test result with the preset electrical signal.

[0107] The test results of the needle pressure test include needle pressure results and needle mark results. The needle pressure result is the electrical signal result generated by the electrical connection between the probe 22 and the wafer 30, and the needle mark result is the physical result generated by the insertion of the probe 22 into the wafer 30. Specifically, the test device 27 further compares the electrical signal in the test results with a preset electrical signal, wherein the preset electrical signal may be a preset voltage threshold range and / or current threshold range.

[0108] Step S14: In response to the mismatch between the electrical signal in the test result and the preset electrical signal, adjust the distance the wafer moves toward the probe based on the needle pressure data in the test result and the needle pressure data of the wafer's reference point to retest the wafer.

[0109] In response to a mismatch between the electrical signal in the test results and the preset electrical signal, the control device 25 adjusts the distance the wafer 30 moves toward the probe 22 based on the needle pressure data in the test results and the needle pressure data of the reference point of the wafer 30, so as to retest the wafer 30.

[0110] Specifically, if the testing device 27 determines that the electrical signal in the test result is not within the preset electrical signal, it proves that the test result obtained by the probe point of the wafer 30 through the needle pressure test does not meet the requirements, and it is necessary to further adjust the distance that the wafer 30 moves towards the probe 22.

[0111] The testing device 27 automatically calculates the adjustment value based on the needle pressure at the reference point of the wafer 30 and the electrical signal in the test results, and transmits the adjustment value to the first control device 251 to adjust the distance the wafer 30 moves toward the probe 22.

[0112] Optionally, the process of adjusting the distance the wafer moves towards the probe based on the needle pressure data in the test results and the needle pressure data at the wafer's reference point can be as follows: Figure 7 Please refer to the process shown below. Figure 7 , Figure 7 yesFigure 6 A detailed flowchart of step S14 is provided. Specifically, it includes the following steps:

[0113] Step S141: Obtain the standard parameter table.

[0114] The standard parameter table is used to calibrate the needle pressure data corresponding to different electrical signals generated by the wafer 30. Since the needle pressure data corresponds to the depth of the probe 22 inserted into the wafer 30, the different electrical signals corresponding to different depths of the probe 22 inserted into the wafer 30 can be obtained according to the standard parameters. The electrical signals include at least one of standard voltage and / or standard current.

[0115] Step S142: Obtain the first needle pressure data corresponding to the electrical signal in the test results based on the standard parameter table.

[0116] The testing device 27 acquires a standard parameter table and reads the first needle pressure data corresponding to the electrical signal in the test result according to the standard parameter table, so as to obtain the first depth of the probe 22 inserted into the wafer 30 that matches the test result.

[0117] Step S143: Adjust the distance the wafer moves toward the probe based on the needle pressure data of the first needle pressure data and the needle pressure data of the wafer reference point.

[0118] Specifically, the testing device 27 reads the needle pressure data that matches the center value of a preset electrical signal within a preset threshold range according to a standard parameter table, thereby obtaining the second insertion depth of the probe 22 into the wafer 30 that matches the center value of the preset electrical signal. The testing device 27 further adjusts the distance the wafer 30 moves towards the probe 22 based on the difference between the first and second depths.

[0119] Optionally, the process of adjusting the distance the wafer moves toward the probe based on the needle pressure data of the first needle pressure data and the needle pressure data of the wafer's reference point can be as follows: Figure 8 Please refer to the process shown below. Figure 8 , Figure 8 yes Figure 7 A detailed flowchart of the first embodiment of step S143 is shown. Specifically, it includes the following steps:

[0120] Step S1431: In response to the first needle pressure data being greater than the needle pressure data of the reference point of the wafer, calculate the first difference between the first needle pressure data and the needle pressure data of the reference point of the wafer.

[0121] In response to a first needle pressure data point being greater than the needle pressure data point of the wafer's reference point, the testing device 27 calculates a first difference between the first needle pressure data point and the needle pressure data point of the wafer's reference point, i.e., calculates a first difference between the first depth and the second depth, thereby obtaining a needle pressure adjustment value. The distance the wafer 30 moves towards the probe 22 is adjusted based on this needle pressure adjustment value. Specifically, when the first difference is positive, the needle pressure adjustment value is added to either a second preset distance or a third preset distance used for needle pressure testing.

[0122] Step S1432: Reduce the moving distance of the wafer to the probe based on the first difference, so that the difference between the adjusted moving distance and the original moving distance is equal to the first difference.

[0123] In this process, after adjusting the distance of the wafer 30 moving towards the probe 22 according to step S1431, the moving distance of the wafer 30 towards the probe 22 is reduced based on the first difference, so that the difference between the adjusted moving distance and the moving distance before adjustment is equal to the first difference, thereby obtaining a new second preset distance or a third preset distance. The wafer needle pressure test system 20 repeats the needle pressure test on the wafer 30 according to the new second preset distance or the third preset distance to obtain a new needle pressure test result. The test device 27 determines whether the electrical signal in the new needle pressure test result matches the preset electrical signal, until it is determined that the electrical signal in the new needle pressure test result matches the preset electrical signal, stores the new second preset distance or the third preset distance and replaces the original second preset distance or the third preset distance of the needle pressure test.

[0124] Optionally, when the testing device 27 determines that the electrical signal in the test result of the pin pressure test matches the preset electrical signal, it proves that the test result obtained by the probe point of the wafer 30 performing the pin pressure test according to the new second preset distance or third preset distance meets the requirements. The new second preset distance or third preset distance is the excellent parameter for the corresponding test point to complete the pin pressure test. The new second preset distance or third preset distance can be stored as a historical experience value to adjust the moving distance when the next probe point of the wafer 30 performs the pin pressure test.

[0125] Optionally, the process of adjusting the distance the wafer moves toward the probe based on the needle pressure data of the first needle pressure data and the needle pressure data of the wafer's reference point can also be as follows: Figure 9 Please refer to the process shown below. Figure 9 , Figure 9 yes Figure 7 A detailed flowchart of the second embodiment of step S143 is shown. Specifically, it includes the following steps:

[0126] Step S1433: In response to the first needle pressure data being less than the needle pressure data of the reference point of the wafer, calculate the second difference between the first needle pressure data and the needle pressure data of the reference point of the wafer.

[0127] In response to the first needle pressure data being less than the needle pressure data at the wafer's reference point, the testing device 27 calculates a second difference between the first needle pressure data and the needle pressure data at the wafer's reference point, i.e., calculates a second difference between the second depth and the first depth, thereby obtaining a needle pressure adjustment value. The distance the wafer 30 moves towards the probe 22 is adjusted according to this needle pressure adjustment value. Specifically, when the second difference is negative, the needle pressure adjustment value is subtracted from either a second preset distance or a third preset distance used for needle pressure testing.

[0128] Step S1434: Increase the moving distance of the wafer towards the probe based on the first difference, so that the difference between the adjusted moving distance and the original moving distance is equal to the second difference.

[0129] In this process, after adjusting the distance of the wafer 30 moving towards the probe 22 according to step S1433, the moving distance of the wafer 30 towards the probe 22 is increased based on the first difference, so that the difference between the adjusted moving distance and the moving distance before adjustment is equal to the second difference, thereby obtaining a new second preset distance or a third preset distance. The wafer needle pressure test system 20 repeats the needle pressure test on the wafer 30 according to the new second preset distance or the third preset distance to obtain a new needle pressure test result. The test device 27 determines whether the electrical signal in the new needle pressure test result matches the preset electrical signal, until it is determined that the electrical signal in the new needle pressure test result matches the preset electrical signal, stores the new second preset distance or the third preset distance and replaces the original second preset distance or the third preset distance of the needle pressure test.

[0130] Optionally, when the testing device 27 determines that the electrical signal in the test result of the pin pressure test matches the preset electrical signal, it proves that the test result obtained by the probe point of the wafer 30 performing the pin pressure test according to the new second preset distance or third preset distance meets the requirements. The new second preset distance or third preset distance is the excellent parameter for the corresponding test point to complete the pin pressure test. The new second preset distance or third preset distance can be stored as a historical experience value to adjust the moving distance when the next probe point of the wafer 30 performs the pin pressure test.

[0131] The wafer pin pressure testing system 20 of this application scans the wafer 30 using a scanning device 23. Based on the scanning results, a recording device 24 calculates the overall warpage of the wafer 30. Simultaneously, an optimal pin pressure value (i.e., a first preset distance) is preset at the center point of the wafer 30, and the optimal pin pressure data for the wafer 30 is determined using this first preset distance. Then, a first control device 251 calculates the distance the wafer 30 should move towards the probe 22 when performing pin pressure testing on each probe point of the wafer 30, based on the overall warpage and the optimal pin pressure data. A second control device 252 then moves the support stage 21 according to this distance, thereby moving the wafer 30 so that each probe point of the wafer 30 can be subjected to corresponding pin pressure testing. Furthermore, the wafer pin pressure testing system 20 of this application features an adjustable support 28 with a curved surface on the support stage 21, suitable for wafers 30 of various shapes and sizes, achieving effective fixation of the wafer 30.

[0132] On the other hand, the moving distances of the multiple probe points of the wafer 30 in this application are not exactly the same, so as to avoid using the same needle pressure value to perform needle pressure testing on the three-dimensional integrated wafer, which could lead to poor contact or puncture of the chip metal pins.

[0133] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A wafer pin indentation test method, characterized in that, include: S11: Obtain the overall warpage of the wafer and the needle pressure data of the wafer. The overall warpage of the wafer characterizes the height of the surface of the wafer in contact with the probe. The step of obtaining the needle pressure data of the wafer includes: controlling the wafer to move towards the probe by a first preset distance to test the needle pressure data of a reference point of the wafer using the probe. The needle pressure data of the reference point of the wafer is the needle pressure data of the wafer. The reference point of the wafer is the center point of the wafer. The first preset distance is the depth to which the tip of the probe penetrates downward from the center point of the wafer along a direction perpendicular to the support platform used to support the wafer. S12: Based on the overall warpage and the needle pressure data of the wafer, control the moving distance of the wafer toward the probe to perform needle pressure test on each probe point of the wafer; S13: Compare the electrical signal in the test result with the preset electrical signal; S14: In response to the mismatch between the electrical signal in the test result and the preset electrical signal, adjust the distance the wafer moves toward the probe based on the needle pressure data in the test result and the needle pressure data of the reference point of the wafer, so as to retest the wafer; The step of adjusting the distance the wafer moves toward the probe based on the needle pressure data in the test results and the needle pressure data of the reference point of the wafer includes: Obtain a standard parameter table; wherein, the standard parameter table is used to calibrate the needle pressure data corresponding to different electrical signals generated by the wafer; Based on the standard parameter table, obtain the first needle pressure data corresponding to the electrical signal in the test results; The distance the wafer moves toward the probe is adjusted based on the needle pressure data of the first needle pressure data and the needle pressure data of the reference point of the wafer.

2. The method according to claim 1, characterized in that, The step of controlling the movement distance of the wafer towards the probe based on the overall warpage and the wafer's needle pressure data to perform needle pressure testing on each probe point of the wafer includes: In response to the fact that the height of the detection point on the surface of the wafer in contact with the probe is greater than the height of the center point of the wafer, the wafer is controlled to move towards the probe by a second preset distance to perform a needle pressure test on the wafer and obtain the test result; In response to the fact that the height of the detection point on the surface of the wafer in contact with the probe is less than the height of the center point, the wafer is controlled to move towards the probe by a third preset distance to perform a needle pressure test on the wafer and obtain the test result. Wherein, the second preset distance is less than the first preset distance, the third preset distance is greater than the first preset distance, and after moving the second preset distance and / or moving the third preset distance, the needle pressure data of the detection point matches the needle pressure data of the center point of the wafer.

3. The method according to claim 1, characterized in that, The step of adjusting the distance the wafer moves toward the probe based on the needle pressure data of the first needle pressure data and the reference point of the wafer includes: In response to the first needle pressure data being greater than the needle pressure data at a reference point of the wafer, a first difference between the first needle pressure data and the needle pressure data at the reference point of the wafer is calculated; Based on the first difference, reduce the moving distance of the wafer toward the probe so that the difference between the adjusted moving distance and the original moving distance is equal to the first difference; In response to the first needle pressure data being less than the needle pressure data at a reference point of the wafer, a second difference between the needle pressure data at the reference point of the wafer and the first needle pressure data is calculated; The wafer is moved a certain distance toward the probe based on the second difference, so that the difference between the adjusted moving distance and the original moving distance is equal to the second difference.

4. The method according to claim 1, characterized in that, The step of obtaining the overall warpage of the wafer includes: A scan is performed from the center point of the wafer to the edge region of the wafer to obtain at least one scan trajectory that moves in a straight line from the center point of the wafer to the edge region of the wafer; wherein the scan trajectory includes multiple detection points, and the distance between two adjacent detection points within the same scan trajectory is equal; Obtain the height difference between each probe point of the at least one scan trajectory and the center point of the wafer; The overall warpage of the wafer is obtained by fitting the height difference between all the probe points and the center point of the wafer.

5. A wafer pin indentation testing system, characterized in that, include: A support platform is used to support wafers; A probe is positioned on the side of the wafer away from the support stage and is used to perform a needle pressure test on the wafer. A recording device is used to acquire the overall warpage of the wafer, wherein the overall warpage of the wafer characterizes the height of the surface of the wafer in contact with the probe; A control device, connected to the recording device and the carrier stage, is used to acquire needle pressure data of the wafer, and control the movement of the carrier stage based on the overall warpage and the needle pressure data of the wafer, so as to control the moving distance of the wafer toward the probe, so as to perform needle pressure test on each probe point of the wafer; The control device is used to control the wafer to move towards the probe by a first preset distance, so as to use the probe to test the needle pressure data of the reference point of the wafer; the needle pressure data of the reference point of the wafer is the needle pressure data of the wafer, the reference point of the wafer is the center point of the wafer, and the first preset distance is the depth to which the tip of the probe penetrates downward from the center point of the wafer in a direction perpendicular to the support stage. The control device is used for: Compare the electrical signal in the test results with the preset electrical signal; In response to a mismatch between the electrical signal in the test result and the preset electrical signal, the distance the wafer moves toward the probe is adjusted based on the needle pressure data in the test result and the needle pressure data of the reference point of the wafer, so as to retest the wafer; Obtain a standard parameter table; wherein, the standard parameter table is used to calibrate the needle pressure data corresponding to different electrical signals generated by the wafer; Based on the standard parameter table, obtain the first needle pressure data corresponding to the electrical signal in the test results; The distance the wafer moves toward the probe is adjusted based on the needle pressure data of the first needle pressure data and the needle pressure data of the reference point of the wafer.

6. The wafer pin pressure testing system according to claim 5, characterized in that, The wafer pin pressure testing system also includes: An adjustment platform is disposed on the support platform for attaching and fixing the wafer; wherein the center of the adjustment platform coincides with the center of the support platform in a direction perpendicular to the support platform; A scanning device, one end of which is disposed on the support platform and the other end is movably disposed on the side of the wafer away from the support platform, for scanning the wafer to obtain scanning results; The recording device is further connected to the scanning device, and the overall warpage of the wafer is calculated based on the scanning results.

7. The wafer pin pressure testing system according to claim 6, characterized in that, The wafer pin pressure testing system also includes: A collection device, connected to the probe, is used to collect the test results of the probe indentation test on the wafer; A testing device, connected to the collection device and the control device, is used to compare the electrical signal in the test result with a preset electrical signal; In response to a mismatch between the electrical signal in the test result and the preset electrical signal, the control device is further configured to adjust the distance the wafer moves toward the probe based on the needle pressure data in the test result and the needle pressure data of the reference point of the wafer, and retest the wafer.

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