Wafer testing apparatus and wafer testing method

Abstract

The application discloses a wafer testing device and a wafer testing method, wherein the wafer testing device comprises a machine table, a wafer carrier, a vision module and a scanning module; the vision module is located on one side of the wafer carrier in the Z direction and is spaced apart from the wafer carrier, and the vision module faces the sample loading surface; the scanning module is located on the same side of the wafer carrier in the Z direction and is spaced apart from the wafer carrier, and the scanning module faces the sample loading surface. The vision module can preliminarily position the spherical solder joint, the scanning module can scan the positioned spherical solder joint, obtain scanning data including the height of each part of the surface of the spherical solder joint, and accurately measure the height of the highest part of the spherical solder joint after analyzing and comparing the scanning data; the contact height of the probe is set according to the height of the highest part of the spherical solder joint, so that the contact height of the probe is more accurate, and the possibility of damage of the wafer and the probe and inaccurate test data in the test is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer testing apparatus and a wafer testing method. Background Technology

[0002] In fully automated semiconductor wafer testing, automatic wafer height measurement is a crucial step. Since wafer height varies across different products, it's essential to measure the wafer height before using probes for testing. The probe contact height is then controlled based on the wafer height to minimize the possibility of wafer and probe damage and inaccurate test data. While related technologies typically use camera image focusing for measurement, advanced packaged wafers often have spherical solder joints. The contact point with the probe is also spherical, and mainstream lens magnification cannot focus on the top of these spherical solder joints. Therefore, it's impossible to accurately measure the overall wafer height, which still significantly increases the risk of wafer and probe damage and inaccurate test data. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a wafer testing device that can more accurately measure the height of the highest point of the spherical solder joints on the wafer, so as to make the contact height of the probe more accurate and reduce the possibility of wafer and probe damage and inaccurate test data during testing.

[0004] The present invention also provides a wafer testing method applied to the above-mentioned wafer testing apparatus.

[0005] A wafer testing apparatus provided in a first aspect of the present invention is used to test the height of a wafer having protruding spherical solder joints. The wafer testing apparatus includes: a machine base; a wafer stage having a sample carrier surface for fixing the wafer, the sample carrier surface being located in an XY plane, the wafer stage being mounted on the machine base; a vision module located on one side of the wafer stage in the Z direction and spaced apart from the wafer stage, the vision module facing the sample carrier surface, the vision module being used to locate the spherical solder joints to be measured; and a scanning module located on the same side of the wafer stage in the Z direction as the vision module and spaced apart from the wafer stage, the scanning module facing the sample carrier surface, the scanning module being used to scan the spherical solder joints located by the vision module to measure the height of the spherical solder joints.

[0006] The wafer testing apparatus provided in the first aspect of the present invention has at least the following beneficial effects: the wafer testing apparatus is provided with a vision module and a scanning module. The vision module can perform preliminary positioning of the spherical solder joints, and the scanning module can scan the positioned spherical solder joints to obtain scanning data including the height of various points on the surface of the spherical solder joints. After analyzing and comparing the scanning data, the height of the highest point of the spherical solder joints can be measured more accurately. The contact height of the probe can be set according to the height of the highest point of the spherical solder joints, which can make the contact height of the probes more accurate and reduce the possibility of wafer and probe damage and inaccurate test data during testing.

[0007] In some embodiments of the present invention, the wafer testing apparatus further includes a motion component, the motion component including a first slider and a second slider, the first slider being slidably connected to the second slider and capable of moving relative to the second slider in the X direction, the second slider being slidably connected to the machine platform and capable of moving relative to the machine platform in the Y direction, and the wafer stage being connected to the first slider.

[0008] In some embodiments of the present invention, the motion component further includes a third slider connected to the first slider and capable of moving relative to the first slider in the Z direction, and the wafer stage is connected to the third slider.

[0009] In some embodiments of the present invention, the wafer testing apparatus further includes a probe module, wherein the probe module, the vision module, and the scanning module are all located on the same side of the wafer stage in the Z direction and are spaced apart from the wafer stage. The probe module has a probe for contacting the spherical solder joint and is used to test the spherical solder joint after the height measurement has been completed.

[0010] In some embodiments of the present invention, the wafer testing apparatus further includes a support bracket connected to the machine base, and the vision module, the scanning module, and the probe module are all mounted on the support bracket.

[0011] In some embodiments of the present invention, the vision module and the scanning module are arranged sequentially along the Y direction, or the vision module and the scanning module are arranged sequentially along the X direction.

[0012] In some embodiments of the present invention, the scanning module is a capacitive sensor or a 3D scanner.

[0013] A wafer testing method provided in a second aspect of the present invention is applied to the wafer testing apparatus described in any embodiment of the first aspect of the present invention, for testing the height of a wafer. The wafer testing method includes the steps of: using a vision module to locate a spherical solder joint on the wafer through contour recognition; using a scanning module to scan the located spherical solder joint and acquire scanning data; analyzing the scanning data to obtain the height of the highest point of the spherical solder joint; controlling the contact height between a probe and the spherical solder joint according to the height of the highest point of the spherical solder joint, and using the probe to contact the spherical solder joint to test the wafer.

[0014] The wafer testing method provided by the second aspect of the present invention has at least the following beneficial effects: a vision module is used to initially locate the spherical solder joint, and then a scanning module is used to scan the located spherical solder joint to obtain scanning data including the height of various points on the surface of the spherical solder joint. After analyzing and comparing the scanning data, the height of the highest point of the spherical solder joint can be measured more accurately. The contact height of the probe can be set according to the height of the highest point of the spherical solder joint, which can make the contact height of the probe more accurate and reduce the possibility of wafer and probe damage and inaccurate test data during testing.

[0015] In some embodiments of the present invention, the wafer testing method further includes the steps of: calibrating the position coordinates of the vision module and the scanning module before the vision module locates a spherical solder joint on the wafer through contour recognition; after the vision module locates a spherical solder joint on the wafer through contour recognition and before the scanning module scans the located spherical solder joint, the locationd spherical solder joint is transformed according to the calibrated coordinates, and then moved to the transformed coordinates so that the locationd spherical solder joint is located at the scanning position of the scanning module.

[0016] In some embodiments of the present invention, the step of using a scanning module to scan the positioned spherical solder joint includes the steps of: moving the wafer along the X direction so that the scanning module scans the positioned spherical solder joint along the X direction; or, moving the wafer along the Y direction so that the scanning module scans the positioned spherical solder joint along the Y direction.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 A perspective view of a wafer testing apparatus provided for some embodiments of the first aspect of the present invention;

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 A flowchart of a wafer testing method provided for some embodiments of the second aspect of the present invention;

[0022] Figure 4 for Figure 3 The flowchart of step S200 of the wafer testing method shown;

[0023] Figure 5 A flowchart of step S200 of a wafer testing method provided for some embodiments of the second aspect of the present invention.

[0024] Figure label:

[0025] The machine tool is 100, the wafer stage is 200, the motion component is 300, the first slider is 310, the second slider is 320, the third slider is 330, the vision module is 400, the scanning module is 500, the probe module is 600, the support is 700, the wafer is 800, and the spherical solder joint is 810. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0028] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0029] In the description of this invention, references to terms such as "one embodiment," "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] Reference Figure 1 The first aspect of the present invention provides a wafer testing apparatus, including a machine base 100, a wafer stage 200, a vision module 400, and a scanning module 500. The wafer stage 200 has a sample-carrying surface for fixing a wafer 800, the sample-carrying surface being located in the XY plane, and the wafer stage 200 is mounted on the machine base 100. The vision module 400 is located on one side of the wafer stage 200 in the Z direction and is spaced apart from the wafer stage 200. The vision module 400 faces the sample-carrying surface and is used to locate the spherical solder joint 810 to be measured. The scanning module 500 and the vision module 400 are... The scanning module 500 is located on the same side of the wafer stage 200 in the Z direction and is spaced apart from the wafer stage 200. The scanning module 500 faces the sample surface and is used to scan the spherical solder joint 810 positioned by the vision module 400 to measure the height of the spherical solder joint 810. Specifically, the scanning module 500 is a capacitive sensor or a 3D scanner. Both the capacitive sensor and the 3D scanner can measure the distance between different positions on the surface of the spherical solder joint 810 and the scanning module 500, i.e., the height of different positions on the surface of the spherical solder joint 810, and acquire scanning data. The wafer testing device is used to test the height of the wafer 800, as shown in the reference... Figure 2 The wafer 800 has protruding spherical solder joints 810. The vision module 400 can perform preliminary positioning of the spherical solder joints 810, and the scanning module 500 can scan the positioned spherical solder joints 810 to obtain scanning data including the height of various points on the surface of the spherical solder joints 810. After analyzing and comparing the scanning data, the height of the highest point of the spherical solder joints 810 can be measured more accurately. The contact height of the probe can be set according to the height of the highest point of the spherical solder joints 810, which can make the contact height of the probe more accurate and reduce the possibility of damage to the wafer 800 and probes and inaccurate test data during testing.

[0031] The wafer 800 has multiple arrayed spherical solder joints 810. Height measurement is required for each spherical solder joint 810 on the wafer 800. Therefore, for the same wafer 800, each spherical solder joint 810 must first be aligned with the vision module 400 for positioning, and then aligned with the scanning module 500 to complete the scanning. Based on this, referring to... Figure 1The wafer testing apparatus also includes a motion component 300, which includes a first slider 310 and a second slider 320. The first slider 310 is slidably connected to the second slider 320 and can move relative to the second slider 320 in the X direction. The second slider 320 is slidably connected to the machine platform 100 and can move relative to the machine platform 100 in the Y direction. The wafer stage 200 is connected to the first slider 310. The motion component 300 can drive the wafer stage 200 to move in the XY plane so that the spherical solder joints 810 at different positions on the wafer 800 are aligned with the vision module 400 or the scanning module 500, thereby successfully completing the positioning and scanning of the spherical solder joints 810. In use, the vision module 400 and the scanning module 500 remain stationary, while the motion component 300 moves the wafer stage 200 to align the spherical solder points 810 at different positions on the wafer 800 with the vision module 400 or the scanning module 500. The relative positions of the vision module 400 and the scanning module 500 are not easily changed, and the positional accuracy of moving the spherical solder points 810, which have been positioned by the vision module 400, to the scanning module 500 is also easier to ensure, which helps to ensure the accuracy of the measurement results.

[0032] It is understood that, specifically, a guide rail extending in the X direction can be provided on the second slider 320, so that the first slider is slidably connected to the guide rail on the second slider 320; and a guide rail extending in the Y direction can be provided on the machine base 100, so that the second slider 320 is slidably connected to the guide rail on the machine base 100.

[0033] Furthermore, referring to Figure 1 The motion component 300 also includes a third slider 330, which is connected to the first slider 310 and can move relative to the first slider 310 in the Z direction. The wafer stage 200 is connected to the third slider 330. The third slider 330 can drive the wafer stage 200 to move in the Z direction to adjust the distance between the wafer stage 200 and the vision module 400 and the scanning module 500 in the Z direction.

[0034] It is understandable that, specifically, a guide rail extending along the Z direction can be provided on the first slider 310, so that the third slider 330 is slidably connected to the guide rail on the first slider 310.

[0035] Furthermore, referring to Figure 1The wafer testing apparatus also includes a probe module 600. The probe module 600, vision module 400, and scanning module 500 are all located on the same side of the wafer stage 200 in the Z direction and spaced apart from the wafer stage 200. The probe module 600 has probes for contacting the spherical solder joints 810, used to test the spherical solder joints 810 whose height has been measured. By all three modules (probe module 600, vision module 400, and scanning module 500) on the same side of the wafer stage 200 in the Z direction, during testing, the vision module 400 first positions the spherical solder joints 810 on the wafer 800, then the scanning module 500 scans the spherical solder joints 810, and finally the probe module 600 tests the spherical solder joints 810. In this process, the wafer 800 only needs to move within the XY plane, which helps reduce the difficulty of positioning the spherical solder joints 810 and ensures the positional accuracy of the spherical solder joints 810.

[0036] It is understandable that the probe module 600 can be configured with multiple arrays of probes, and the spacing and distribution of the probes correspond to the multiple arrays of spherical solder joints 810 on the wafer 800, so that the probe module 600 can contact multiple spherical solder joints 810 at the same time, thereby improving testing efficiency.

[0037] Furthermore, referring to Figure 1 The wafer testing apparatus also includes a support 700, which is connected to the machine base 100. The vision module 400, scanning module 500, and probe module 600 are all mounted on the support 700. The support 700 provides mounting positions for the vision module 400, scanning module 500, and probe module 600, allowing them to be stably fixed to one side of the wafer stage 200 in the Z direction, improving structural stability and enhancing the accuracy of their relative positions. This makes it easier to ensure the positional accuracy of moving the spherical solder joint 810, which has been positioned by the vision module 400, to the scanning module 500, and to the probe module 600, which has been scanned. This contributes to ensuring the accuracy of the measurement results.

[0038] Furthermore, referring to Figure 1 The vision module 400 and the scanning module 500 are arranged sequentially along the Y direction. The motion component 300 has a first slider 310 that can move along the X direction and a second slider 320 that can move along the Y direction. The vision module 400 and the scanning module 500 are arranged sequentially along the Y direction. After the vision module 400 positions the spherical solder joint 810, it moves the wafer 800 so that the positioned spherical solder joint 810 is moved to the scanning module 500. Only the wafer 800 needs to be moved in the Y direction. The control logic is relatively simple, which is conducive to improving the accuracy of movement.

[0039] It is understood that in some other embodiments, the vision module 400 and the scanning module 500 may be arranged sequentially along the X direction. After the vision module 400 positions the spherical solder joint 810, the wafer 800 is moved so that the positioned spherical solder joint 810 is moved to the scanning module 500. Only the wafer 800 needs to be moved in the X direction.

[0040] Reference Figure 3 The second aspect of the present invention provides a wafer testing method, applied to the wafer testing apparatus of any embodiment of the first aspect of the present invention, for testing the height of a wafer 800. The wafer testing method includes the following steps:

[0041] S100 uses a vision module 400 to locate a spherical solder joint 810 on a wafer 800 through contour recognition;

[0042] S200 uses scanning module 500 to scan the positioned spherical solder joint 810 and acquire scanning data;

[0043] S300 analyzes the scanned data to obtain the height of the highest point of the spherical solder joint 810;

[0044] S400 controls the contact height between the probe and the spherical solder joint 810 based on the height of the highest point of the spherical solder joint 810, and uses the probe to contact the spherical solder joint 810 to test the wafer 800.

[0045] The vision module 400 is used to initially locate the spherical solder joint 810, and then the scanning module 500 is used to scan the located spherical solder joint 810 to obtain scanning data including the height of various points on the surface of the spherical solder joint 810. After analyzing and comparing the scanning data, the height of the highest point of the spherical solder joint 810 can be measured more accurately. The contact height of the probe can be set according to the height of the highest point of the spherical solder joint 810, which can make the contact height of the probe more accurate and reduce the possibility of damage to the wafer 800 and probes and inaccurate test data during testing.

[0046] It should be noted that the wafer 800 has multiple spherical solder joints 810 arranged in an array. In actual testing, the height of some or all of the spherical solder joints 810 on the wafer 800 can be measured by repeating steps S100 to S300, and then the wafer 800 can be tested by implementing step S400.

[0047] Furthermore, referring to Figure 3 The wafer testing method also includes the following steps:

[0048] S500, before step S100, calibrate the position coordinates of the vision module 400 and the scanning module 500;

[0049] S600, after step S100 and before step S200, the spherical solder joint 810 that has been positioned is transformed according to the calibrated coordinates, and then the spherical solder joint 810 that has been positioned is moved to the transformed coordinates so that the spherical solder joint 810 is located at the scanning position of the scanning module 500.

[0050] In actual use, during the device debugging phase before testing, the position coordinates of the vision module 400 and the scanning module 500 are calibrated. Then, the testing begins. After the spherical solder joint 810 is positioned, the coordinates of the spherical solder joint 810 are transformed according to the position coordinates of the vision module 400 and the scanning module 500 calibrated during the debugging phase. The spherical solder joint 810 is then moved to the transformed coordinates, and scanning can be performed. This is convenient and quick, and helps to improve testing efficiency.

[0051] Furthermore, referring to Figure 4 S200 includes the following steps:

[0052] S210, move wafer 800 along the X direction so that scanning module 500 scans the positioned spherical solder joint 810 along the X direction.

[0053] In other embodiments, reference is made to Figure 5 S200 includes the following steps:

[0054] S220, move wafer 800 along the Y direction so that scanning module 500 scans the positioned spherical solder joint 810 along the Y direction.

[0055] Moving the wafer 800 in a single direction allows the scanning module 500 to scan the spherical solder joint 810 in that direction. This ensures that the scanning module 500 scans the entire surface of the spherical solder joint 810, and the control logic during movement is relatively simple, which helps to improve testing efficiency while ensuring the accuracy of measurement results.

[0056] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A wafer testing apparatus for testing the height of a wafer, said wafer having protruding spherical solder joints, characterized in that, The wafer testing apparatus includes: Machine tool; A wafer stage has a sample-carrying surface for fixing the wafer, the sample-carrying surface being located in the XY plane, and the wafer stage being mounted on the machine tool; A vision module is located on one side of the wafer stage in the Z direction and is spaced apart from the wafer stage. The vision module faces the sample surface and is used to locate the spherical solder joint to be measured. The scanning module is located on the same side of the wafer stage in the Z direction as the vision module and is spaced apart from the wafer stage. The scanning module faces the sample surface and is used to scan the spherical solder joint located by the vision module to measure the height of the spherical solder joint and obtain the height of the highest point of the spherical solder joint.

2. The wafer testing apparatus according to claim 1, characterized in that, The wafer testing apparatus further includes a motion component, which includes a first slider and a second slider. The first slider is slidably connected to the second slider and can move relative to the second slider in the X direction. The second slider is slidably connected to the machine platform and can move relative to the machine platform in the Y direction. The wafer stage is connected to the first slider.

3. The wafer testing apparatus according to claim 2, characterized in that, The motion assembly further includes a third slider, which is connected to the first slider and is movable relative to the first slider in the Z direction, and the wafer stage is connected to the third slider.

4. The wafer testing apparatus according to claim 1, characterized in that, The wafer testing apparatus further includes a probe module, which, along with the vision module and the scanning module, is located on the same side of the wafer stage in the Z direction and is spaced apart from the wafer stage. The probe module has probes for contacting the spherical solder joints and is used to test the spherical solder joints that have undergone height measurement.

5. The wafer testing apparatus according to claim 4, characterized in that, The wafer testing apparatus also includes a support frame connected to the machine base, and the vision module, the scanning module, and the probe module are all mounted on the support frame.

6. The wafer testing apparatus according to claim 1, characterized in that, The vision module and the scanning module are arranged sequentially along the Y direction, or the vision module and the scanning module are arranged sequentially along the X direction.

7. The wafer testing apparatus according to claim 1, characterized in that, The scanning module is a capacitive sensor or a 3D scanner.

8. A wafer testing method, applied to the wafer testing apparatus according to any one of claims 1 to 7, for testing the height of a wafer, characterized in that, The wafer testing method includes the following steps: A vision module is used to locate a spherical solder joint on the wafer through contour recognition; The spherical solder joints that have been located are scanned using a scanning module to obtain scanning data; The height of the highest point of the spherical weld joint is obtained by analyzing the scan data. Based on the height of the highest point of the spherical solder joint, the contact height between the probe and the spherical solder joint is controlled, and the probe is used to contact the spherical solder joint to test the wafer.

9. The wafer testing method according to claim 8, characterized in that, The wafer testing method further includes the following steps: Before the vision module locates a spherical solder joint on the wafer through contour recognition, the position coordinates of the vision module and the scanning module are calibrated. After the vision module locates a spherical solder joint on the wafer through contour recognition, and before the scanning module scans the located spherical solder joint, the coordinates of the located spherical solder joint are transformed according to the calibrated coordinates. The located spherical solder joint is then moved to the transformed coordinates so that the located spherical solder joint is located at the scanning position of the scanning module.

10. The wafer testing method according to claim 8, characterized in that, The step of scanning the located spherical solder joints using a scanning module includes the following steps: The wafer is moved along the X direction, so that the scanning module scans the positioned spherical solder joints along the X direction; or, The wafer is moved along the Y direction so that the scanning module scans the positioned spherical solder joints along the Y direction.

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