Method and device for measuring offset of bonding pair

Abstract

The invention discloses a method and a device for measuring the offset of a bonding pair. The method comprises the following steps: (1) respectively acquiring images of two opposite boundaries of an upper module and a lower module in a to-be-measured bonding pair in a first horizontal direction, and determining offsets of the upper module and the lower module in the first horizontal direction at the moment according to the images, and recording the offsets as first measurement offsets; (2) rotating the bonding pair to be detected by 180 degrees; (3) repeating the step (1), and recording the offset determined in the step as a second measurement offset; (4) subtracting the second measurement offset from the first measurement offset and taking a half of the first measurement offset to obtain a correction offset of the bonding pair to be measured in the first radial direction; wherein the first radial direction is parallel to the first horizontal direction. According to the invention, the measurement efficiency and accuracy of the bonding pair offset can be improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method and apparatus for measuring bond pair offset. Background Technology

[0002] In recent years, with the rapid development of 5G, artificial intelligence, the Internet of Things, autonomous driving, and big data, electronic devices are evolving towards multifunctionality, high bandwidth, and low power consumption. To achieve high performance in electronic devices, some semiconductor companies have pioneered advanced 2.5D and 3D packaging technologies for mass production (such as intermediate dielectric layers, through-silicon vias, multilayer stacking, and package-on-package). Temporary bonding is one of the most critical processes in this field. The purpose of temporary bonding and debonding processes is to fix and protect ultra-thin wafers or reduce warpage caused by wafer EMC (epoxy molding compound). After completing the temporary bonding and debonding process (TBDB), bond pair offset, warpage, and TTV (Total Thickness Variation) need to be measured to macroscopically check the bonding effect of the bond pairs.

[0003] In 2.5D and 3D applications, most TBDBs developed by OSAT (Outsourced Semiconductor Assembly and Test) generally have the following problems in offset measurement: 1. Measurement error: The offset after the temporary debonding process in the OSAT section is manually measured using 3D profile (optical profilometer), which has a large measurement error and low measurement efficiency.

[0004] 2. Calculation error: There is a calculation error in calculating the maximum bond offset of the bond pair based on the collected single or multiple offset data.

[0005] Furthermore, since the boundaries of wafers or substrates are defined by the measurement equipment operator based on experience, the boundary definition may be affected by changes in actual illumination or imaging shadow effects, leading to incorrect boundary definition and thus introducing measurement errors.

[0006] Therefore, how to quickly and accurately measure the bond pair offset has become an urgent problem to be solved. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method and apparatus for measuring bond pair offset, which can realize automated measurement and improve the measurement efficiency and accuracy of bond pair offset.

[0008] In a first aspect, the present invention provides a method for measuring bond pair offset, comprising: (1) Obtain images of the two boundaries of the upper and lower modules in the bond pair to be tested in the first horizontal direction respectively, and determine the offset of the upper and lower modules in the first horizontal direction at this time based on the images, which is recorded as the first measurement offset; (2) Rotate the bond pair to be tested by 180 degrees; (3) Repeat step (1) and record the offset determined in this step as the second measurement offset; (4) Subtract the second measurement offset from the first measurement offset and take half of it to obtain the corrected offset ShiftX of the bond pair to be tested in the first radial direction; wherein the first radial direction is parallel to the first horizontal direction.

[0009] In a second aspect, the present invention also provides a device for measuring bond pair offset, comprising: The testing station is used to support and fix the bond pair to be tested; An image acquisition device includes an objective lens, the image acquisition device being used to acquire images within the field of view of the objective lens; A driving device is connected to the testing station and includes a moving driving component and a rotating driving component connected to each other; the rotating driving component is used to drive the testing station to rotate the bond pair under test around a vertical axis, and the moving driving component is used to drive the testing station to move the bond pair under test. The control module is electrically connected to the image acquisition device and the driving device; the control module includes a processor and a storage module, the storage module stores one or more operation instructions, the one or more operation instructions can be executed by the processor to implement the bond pair offset measurement method as described above.

[0010] The beneficial effects of this invention are as follows: By acquiring boundary images of the upper and lower modules of the bond pair under test relative to each other in the diametrical direction, and through image processing and analysis, the offset of the upper and lower modules in this diametrical direction can be quickly calculated; by measuring the offset before and after the bond pair rotates 180 degrees, and using the offset obtained from the two measurements, the offset of the bond pair under test in the first radial direction can be calculated, thereby eliminating the offset measurement error caused by incorrect boundary definition and improving the accuracy of bond pair offset measurement. This invention enables automated measurement of bond pair offset, improving the measurement efficiency and accuracy of bond pair offset. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of bond pair measurement without systematic errors; Figure 2This is a schematic diagram of bond pair measurement when there are systematic errors; Figure 3 A flowchart of a method for measuring bond pair offset provided by the present invention; Figure 4 A schematic diagram of the structure of a bonding pair offset measuring device provided by the present invention; Figure 5 This is a flowchart of a method for measuring bond pair offset according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a bonding pair offset measuring device according to an embodiment of the present invention; Figure 7 This is a partial schematic diagram of the upper module imaging according to an embodiment of the present invention; Figure 8 This is a partial schematic diagram of the lower module imaging according to an embodiment of the present invention.

[0012] Label Explanation: 1. Testing table; 2. Image acquisition device; 3. Drive device; 4. Control module; 21. Objective lens; 22. Imaging unit; 31. Motion drive component; 32. Rotation drive component; 41. Processor; 42. Storage module; 51. Upper module; 52. Lower module. Detailed Implementation

[0013] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0014] like Figure 1 As shown, assuming the center of the upper module in the bond pair is O1, and the X-axis coordinates of the two sides of the upper module in the X-axis direction are X1 and X2 respectively, and the center of the lower module in the bond pair is O2, and the X-axis coordinates of the two sides of the lower module in the X-axis direction are X3 and X4 respectively, then the X-axis coordinate of O1 is X1. O1 =(X1+X2) / 2, where X is the coordinate of O2 on the X-axis. O2 =(X3+X4) / 2.

[0015] At this point, the left offset of the bond pair is ShiftX. left =X2-X4, right offset ShiftX right =X1-X3. Where ShiftX... left and ShiftX right The sign is determined by the relative positions of the upper and lower modules along the X-axis. Figure 1 In the case shown, ShiftXleft A positive value indicates that the left boundary of the upper module is offset relative to the left boundary of the lower module in the positive X-axis direction; ShiftX right A negative value indicates that the right boundary of the upper module is offset in the negative X-axis direction relative to the right boundary of the lower module.

[0016] The offset of the bond pair in the X-axis direction, ShiftX, is the center X of the upper module. O1 With the center X of the lower module O2 The difference between them, that is: ShiftX=X O1 -X O2 =(X1+X2) / 2-(X3+X4) / 2 =[(X1-X3)+(X2-X4)] / 2 =(ShiftX left +ShiftX right ) / 2 Similarly, ShiftX is determined by the relative position of the upper and lower modules in the X-axis direction. If ShiftX is positive, it means that the center of the upper module is offset in the positive X-axis direction relative to the center of the lower module, and vice versa.

[0017] For example, when X1=300, X2=-200, X3=350, X4=-310, X O1 =(300+(-200)) / 2=50, X O2 =(350+(-310)) / 2=20. At this time, ShiftX=X O1 -X O2 =50-20=30, meaning the center of the upper module is offset by 30 micrometers relative to the center of the lower module in the positive X-axis direction.

[0018] If ShiftX=(ShiftX) left +ShiftX right The formula ) / 2 is used for calculation because of ShiftX. left =X2-X4=-200-(-310)=110,ShiftX right =X1-X3=300-350=-50, then ShiftX=(110-50) / 2=30, which is the same as the result above.

[0019] It can be seen that the above formula is applicable to the calculation of the offset of bond pairs of any size in the X-axis direction.

[0020] During the measurement process, the boundaries between the upper and lower modules in the bonding pair are defined by the operator of the measurement machine based on experience. When defining the boundaries, the actual illumination may be affected by factors such as changes in the actual light or imaging shadow effects, which may lead to incorrect boundary definition and thus introduce measurement errors.

[0021] For example, such as Figure 2 As shown, the center of the upper module in the bond pair is O1, and the X-axis coordinates of the two sides of the upper module in the X-axis direction are X1 and X2, respectively. The center of the lower module in the bond pair is O2, and the X-axis coordinates of the two sides of the lower module in the X-axis direction are X3 and X4, respectively. Due to systematic errors caused by lighting and shadows, the position corresponding to X1' is mistakenly located as the boundary of the upper module, and the distance between X1' and X1 is Δe.

[0022] At this time, ShiftX left =X2-X4=ShiftX left ; ShiftX right =X1'-X3=X1-Δe-X3=ShiftX right -Δe.

[0023] ShiftX'=(ShiftX left '+ShiftX right ') / 2=(ShiftX left +ShiftX right -Δe) / 2=ShiftX-Δe / 2.

[0024] In other words, the measured offset is increased by -Δe / 2 in systematic error due to the influence of light and shadow.

[0025] Since it is a systematic error, for any similar bond pair, the theoretically measured offset is increased by -Δe / 2 compared to the actual offset. If a new bond pair is constructed, and the actual offset of this new bond pair is opposite to that of the previous bond pair (this new bond pair is actually the original bond pair rotated by 180 degrees), then the measured offset of this new bond pair, ShiftX'', is equal to -ShiftX - Δe / 2.

[0026] To eliminate systematic errors and determine the actual offset of the bond pair, the following method can be used: ShiftX'-ShiftX''=ShiftX-Δe / 2-(-ShiftX-Δe / 2)=2ShiftX; That is, the actual offset ShiftX is half of the offset measured before and after the bond pair rotates 180 degrees. Therefore, ShiftX = (ShiftX0 - ShiftX) / (ShiftX0 - ShiftX0 ... 180 ) / 2, where ShiftX0 represents the offset measured before rotation, ShiftX 180 This indicates the offset measured after rotating 180 degrees.

[0027] Therefore, measuring the offset of bond pairs using the method corresponding to the above formula can effectively eliminate systematic errors. Moreover, these errors are not limited to those caused by light and shadow. Theoretically, any systematic errors that are repeatedly introduced during the measurement process can be eliminated or reduced to a certain extent.

[0028] For example, assuming that before rotation, X1=300, X2=-200, X3=350, X4=-310, then X1'=300-Δ; the offset measured before rotation: ShiftX0=(ShiftX 0-left +ShiftX 0-right ) / 2 =[-200-(-310)+(300-Δe)-350] / 2=30-Δe / 2 After the bond pair is rotated 180 degrees around the Z-axis, X1=200, X2=-300, X3=310, X4=-350, and at this point, X1'=200-Δ; the offset measured after rotation: ShiftX 180 =(ShiftX 180-left +ShiftX 180-right ) / 2 =[-300-(-350)+(200-Δe)-310] / 2=-30-Δe / 2 Substituting the above results into the formula ShiftX=(ShiftX0-ShiftX) 180 ) / 2=[30-Δe / 2-(-30-Δe / 2)]=30, which shows that it is the same as the calculation result above, and the verification is successful.

[0029] In practical applications, since the measurement scenario does not actually have a coordinate system, and the measurement process identifies the offset by pixel, it is impossible to directly identify the coordinate values ​​of the two side boundaries of the upper and lower modules. In this embodiment, ShiftX is calculated based on the deviation between the two side boundaries.

[0030] Furthermore, since the offset identified by pixels is typically a distance value, i.e., an absolute value, it lacks a positive or negative connotation. Therefore, in this embodiment, the visibility state of the lower module (i.e., the case where the lower module is occluded by the upper module) determines ShiftX.left and ShiftX right The value of ShiftX is positive or negative. A positive value indicates that the lower module is visible in the image (i.e., the lower module is exposed), while a negative value indicates that the lower module is obscured by the upper module in the image (i.e., the lower module is occluded). At this time, ShiftX... left Positive and negative states and Figure 1 The X-axis direction is consistent, while the ShiftX direction is consistent. right Positive and negative states and Figure 1 The X-axis direction is opposite, that is, in the formula derived above, ShiftX=(ShiftX left +ShiftX right In ) / 2, you need to change ShiftX. right Adjusting it to take the negative sign gives the formula ShiftX = (ShiftX) left -ShiftX right ) / 2.

[0031] Based on the above principles, please refer to Figure 3 The present invention provides a method for measuring bond pair offset, comprising: (1) Obtain images of the two boundaries of the upper and lower modules in the bond pair to be tested in the first horizontal direction respectively, and determine the offset of the upper and lower modules in the first horizontal direction based on the images, which is recorded as the first measurement offset; (2) Rotate the bond pair to be tested by 180 degrees; (3) Repeat step (1) and record the offset determined in this step as the second measurement offset; (4) Subtract the second measurement offset from the first measurement offset and take half of it to obtain the corrected offset ShiftX of the bond pair to be tested in the first radial direction; wherein the first radial direction is parallel to the first horizontal direction.

[0032] As can be seen from the above description, the beneficial effect of the present invention is that by measuring the offset before and after the bond pair rotates 180 degrees, and calculating the offset of the bond pair under test in the first radial direction using the offset obtained from the two measurements, the offset measurement error caused by the boundary definition error can be eliminated, thereby improving the measurement accuracy of the bond pair offset.

[0033] In an optional embodiment, the method further includes: (5) Rotate the bond pair to be tested by 90 degrees so that the second radial direction in the bond pair to be tested, which is perpendicular to the first horizontal direction, is rotated to be parallel to the first horizontal direction; (6) Repeat steps (1) to (4) again to obtain the corrected offset ShiftY of the bond pair to be tested in the second radial direction; (7) Calculate the maximum offset of the bond pair to be tested based on the corrected offset ShiftX in the first radial direction and the corrected offset ShiftY in the second radial direction.

[0034] As described above, by rotating the bond pair under test by 90 degrees and then measuring the offset before and after rotating by 180 degrees, the offset in the second radial direction can be obtained. Then, based on the offsets in the mutually perpendicular first and second radial directions and the Pythagorean theorem, the maximum offset of the bond pair under test can be obtained, and the calculation error of the maximum offset can be reduced.

[0035] In an optional embodiment, step (1) includes: (11) Obtain the images of the first boundary and the second boundary of the upper module in the first horizontal direction, and the images of the first boundary and the second boundary of the lower module in the first horizontal direction, respectively, and record them as the first boundary image of the upper module, the second boundary image of the upper module, the first boundary image of the lower module, and the second boundary image of the lower module; (12) Based on the first boundary image of the upper module and the first boundary image of the lower module, determine the first boundary offset of the bonding pair corresponding to the first boundary; based on the second boundary image of the upper module and the second boundary image of the lower module, determine the second boundary offset of the bonding pair corresponding to the second boundary; (13) Based on the first boundary offset and the second boundary offset, the first measured offset of the upper module and the lower module in the first horizontal direction is obtained.

[0036] As described above, by acquiring boundary images of the upper and lower modules of the bond pair under test at their opposite boundaries in the diameter direction, and by analyzing the boundary images of the upper and lower modules at the same boundary, the offset of the upper and lower modules at the same boundary can be quickly obtained. Then, based on the offset of the upper and lower modules at their opposite boundaries, the offset of the bond pair under test in the diameter direction can be calculated.

[0037] In an optional embodiment, the bond pair to be tested is carried on a testing stage, which is used to move and rotate the bond pair to be tested around a vertical axis, so that any boundary of the upper and lower modules in any radial direction can be moved to the focusing area below the objective lens in the image acquisition device.

[0038] As described above, the detection stage enables the movement (including horizontal and vertical movement) and rotation of the bond pairs to be tested, thereby facilitating the acquisition of boundary images.

[0039] In an optional embodiment, step (11) includes: With the detection platform at the same horizontal position, the first boundary image of the upper module and the first boundary image of the lower module are acquired respectively; With the detection platform at the same horizontal position, the second boundary image of the upper module and the second boundary image of the lower module are acquired respectively.

[0040] As described above, by acquiring boundary images of the upper and lower modules at the same horizontal position, the fused image can accurately reflect the relative positional relationship between the upper and lower modules when the boundary images of the upper and lower modules are superimposed, thereby ensuring the accuracy of the offset measurement.

[0041] In an optional embodiment, step (11) includes: when acquiring the first boundary image of the upper module, the first boundary image of the lower module, the second boundary image of the upper module and the second boundary image of the lower module, respectively recording the vertical position of the detection platform, and respectively recording it as the first vertical position, the second vertical position, the third vertical position and the fourth vertical position; Step (3) includes: controlling the detection stage to move to the first vertical position to acquire the second boundary image of the upper module; controlling the detection stage to move to the third vertical position to acquire the first boundary image of the upper module; controlling the detection stage to move to the second vertical position to acquire the second boundary image of the lower module; and controlling the detection stage to move to the fourth vertical position to acquire the first boundary image of the lower module.

[0042] As described above, by recording the vertical position of the acquired boundary image and acquiring the boundary image at the same vertical position after rotating 180 degrees, the number of focusing attempts can be reduced, thereby improving measurement efficiency.

[0043] In an optional embodiment, step (12) includes: The first boundary image of the upper module and the first boundary image of the lower module are superimposed to obtain a first fused image, and the first boundary offset is determined based on the pixel distance between the first boundary of the upper module and the first boundary of the lower module in the first fused image. The second boundary image of the upper module and the second boundary image of the lower module are superimposed to obtain a second fused image. The second boundary offset is determined based on the pixel distance between the second boundary of the upper module and the second boundary of the lower module in the second fused image.

[0044] As described above, by overlaying the boundary images of the upper and lower modules at the same boundary, the offset of the upper and lower modules at the same boundary can be quickly calculated through image analysis, thereby improving measurement efficiency.

[0045] In an optional embodiment, the image acquisition device includes two objective lenses, which are spaced apart along the first horizontal direction and are used to capture images of the two boundaries of the upper and lower modules of the bonding pair under test in any radial direction.

[0046] As described above, by setting two objectives to capture images of the two side boundaries respectively, the time it takes for the detection stage to move the bonding pair boundary to the focusing area below the objective in the image acquisition device can be shortened, thereby improving measurement efficiency.

[0047] like Figure 4 As shown, the present invention also provides a device for measuring bond pair offset, comprising: Test station 1, the test station is used to support and fix the bond pair to be tested; Image acquisition device 2 includes an objective lens 21, which is used to acquire images within the field of view of the objective lens 21; The driving device 3 is connected to the testing station 1 and includes a moving driving component 31 and a rotating driving component 32 connected to each other; the rotating driving component 32 is used to drive the testing station 1 to rotate the bond pair to be tested around the vertical axis, and the moving driving component 31 is used to drive the testing station 1 to move the bond pair to be tested. The control module 4 is electrically connected to the image acquisition device 2 and the driving device 3. The control module 4 includes a processor 41 and a storage module 42. The storage module 42 stores one or more operation instructions, which can be executed by the processor 41 to implement the bond pair offset measurement method as described above.

[0048] Furthermore, two objectives 21 are provided, and the two objectives 21 are arranged at intervals along the first horizontal direction.

[0049] Figure 5 This invention provides a method for measuring bond pair offset, wherein the bond pair to be detected can be a temporary bond pair formed by temporary bonding of a wafer and a carrier, a bi-wafer bond pair formed by bonding wafers to each other, or other types of bond pairs. No specific limitation is made on the type of bond pair here. For example, in one embodiment, the upper module can be a wafer, and the lower module can be a carrier temporarily bonded to the wafer.

[0050] This measurement method is based on, for example Figure 6 The measuring device shown includes a detection platform 1, an image acquisition device 2, a drive device 3, and a control module 4.

[0051] The testing station 1 is used to support and fix the bond pair to be tested. In one embodiment, the testing station may be provided with a placement area mark to indicate the placement position of the bond pair to be tested.

[0052] The image acquisition device 2 includes an objective lens 21 and an imaging unit 22. The objective lens 21 is located between the imaging unit 22 and the testing stage 1. The objective lens 21 is used to capture images of the two opposite boundaries (such as the first boundary and the second boundary in the first horizontal direction) of the upper and lower modules of the bond pair under test in any radial direction. The imaging unit 22 is used to acquire images within the field of view of the objective lens 21.

[0053] In some embodiments, the image acquisition device includes one objective lens. In other embodiments, the image acquisition device includes two objective lenses arranged at a distance from each other along a first horizontal direction, the center distance between the two objective lenses being greater than or equal to the diameter of the bond pair to be tested.

[0054] In some embodiments, the objective lens is a low-magnification, high-depth-of-field objective lens (e.g., 2.5x or 5x). In one embodiment, the objective lens may be integrated into the optical microscope stage.

[0055] The drive device 3 is connected to the test stage 1 and includes a moving drive assembly 31 and a rotating drive assembly 32 connected to each other. The rotating drive assembly 32 is used to drive the test stage 1 to rotate around the vertical axis, so as to drive the bond pair under test to rotate along its axial direction. The moving drive assembly 31 is used to drive the test stage 1 to move, so that the upper module or the lower module in the bond pair under test can move to the focusing area of ​​the objective lens 21 in the image acquisition device 2 at any boundary in any radial direction (such as the first horizontal direction).

[0056] The control module 4 is electrically connected to the image acquisition device 2 and the drive device 3 respectively. It is used to control the drive device 3 to drive the detection stage 1 to move or rotate around the vertical axis, and to control the image acquisition device 2 to acquire the boundary images of the upper and lower modules of the bonding pair under test.

[0057] Reference Figure 5 The method includes the following steps S1 to S7.

[0058] S1: Acquire images of the two boundaries of the upper and lower modules in the bonding pair to be tested in the first horizontal direction, and determine the offset of the upper and lower modules in the first horizontal direction based on the images, which is recorded as the first measurement offset.

[0059] Specifically, this step includes the following steps: S101: Obtain the images of the first boundary (e.g., the left boundary) and the second boundary (e.g., the right boundary) of the upper module in the first horizontal direction (e.g., the left and right directions), and the images of the first boundary and the second boundary of the lower module in the first horizontal direction, and record them as the first boundary image of the upper module, the second boundary image of the upper module, the first boundary image of the lower module, and the second boundary image of the lower module, respectively.

[0060] Specifically, the detection stage is controlled to move horizontally so that the first boundary of the bond pair to be tested moves to below the objective lens of the image acquisition device, so that the first boundary of the bond pair to be tested is within the field of view of the objective lens, and the horizontal position of the detection stage at this time is recorded as the first horizontal position; the detection stage is controlled to move vertically so that the image acquisition device focuses on the first boundary of the upper module and acquires the image of the first boundary of the upper module, that is, by adjusting the height of the detection stage so that the image acquisition device can acquire a clear image of the first boundary of the upper module, and the vertical position of the detection stage at this time is recorded as the first vertical position.

[0061] With the detection platform in the first horizontal position, the detection platform is controlled to move vertically so that the image acquisition device focuses on the first boundary of the lower module and acquires the first boundary image of the lower module. That is, by adjusting the height of the detection platform, the image acquisition device can acquire a clear first boundary image of the lower module, and the vertical position of the detection platform at this time is recorded as the second vertical position.

[0062] The detection stage is controlled to move horizontally so that the second boundary of the bond pair to be tested moves below the objective lens of the image acquisition device, and the horizontal position of the detection stage at this time is recorded as the second horizontal position; the detection stage is controlled to move vertically so that the image acquisition device focuses on the second boundary of the upper module and acquires the image of the second boundary of the upper module, and the vertical position of the detection stage at this time is recorded as the third vertical position.

[0063] With the detection platform in the second horizontal position, the detection platform is controlled to move vertically so that the image acquisition device focuses on the second boundary of the lower module and acquires the image of the second boundary of the lower module. The vertical position of the detection platform at this time is recorded as the fourth vertical position.

[0064] like Figure 7 As shown, the detection stage 1 moves along the axial direction to a suitable working distance from the objective lens 21, and the upper module 51 forms an image, thereby acquiring the boundary image of the upper module 51. Figure 7 and Figure 8 The line with the arrow indicates the imaging optical path. For example... Figure 8 As shown, the detection stage 1 continues to move vertically upwards to a suitable distance, and the oblique light energy of the lower module 52 is received by the objective lens 21. At this time, the lower module 52 forms an image, thereby obtaining the boundary image of the lower module 52. Figure 8The dashed box in the imaging unit indicates the unimaged portion of the lower module.

[0065] S102: Based on the first boundary image of the upper module and the first boundary image of the lower module, determine the first boundary offset of the bonding pair corresponding to the first boundary; based on the second boundary image of the upper module and the second boundary image of the lower module, determine the second boundary offset of the bonding pair corresponding to the second boundary.

[0066] Specifically, the first boundary image of the upper module and the first boundary image of the lower module are superimposed to obtain a first fused image, and the first boundary offset is determined based on the pixel distance between the first boundary of the upper module and the first boundary of the lower module in the first fused image.

[0067] The second boundary image of the upper module and the second boundary image of the lower module are superimposed to obtain a second fused image. The second boundary offset is determined based on the pixel distance between the second boundary of the upper module and the second boundary of the lower module in the second fused image.

[0068] Furthermore, in practical application scenarios, the conversion parameters between pixel distance and actual distance can be calibrated in advance, and then the conversion from pixel distance to actual distance can be realized based on the calibrated conversion parameters.

[0069] S103: Based on the first boundary offset and the second boundary offset, obtain the first measured offset of the upper module and the lower module on the first radial direction X-axis at this time.

[0070] Specifically, the formula for calculating the first measurement offset ShiftX0 is: ShiftX0=(ShiftX 0-left -ShiftX 0-right ) / 2 Among them, ShiftX 0-left For the first boundary offset in step S102, ShiftX 0-right This is the second boundary offset in step S102.

[0071] S2: Rotate the bond pair to be tested by 180 degrees.

[0072] Specifically, the test stage is driven to rotate 180 degrees axially by the rotary drive component in the drive device, so that the bond pair to be tested rotates 180 degrees.

[0073] S3: Repeat step S1 and record the offset determined in this step as the second measurement offset; that is, obtain images of the two boundaries of the upper and lower modules in the first horizontal direction of the bond pair to be tested, and determine the offset of the upper and lower modules in the first horizontal direction based on the images, and record it as the second measurement offset.

[0074] This process includes the following steps: S301: Obtain the images of the first boundary and the second boundary of the upper module in the first horizontal direction, and the images of the first boundary and the second boundary of the lower module in the first horizontal direction, respectively, and denot them as the first boundary image of the upper module, the second boundary image of the upper module, the first boundary image of the lower module, and the second boundary image of the lower module.

[0075] Specifically, the detection stage is controlled to move horizontally so that the first boundary of the bond pair to be tested moves to below the objective lens of the image acquisition device, and the horizontal position of the detection stage at this time is recorded as the third horizontal position; the detection stage is controlled to move vertically to the third vertical position so that the image acquisition device focuses on the first boundary of the upper module and acquires the image of the first boundary of the upper module. With the detection platform in the third horizontal position, control the detection platform to move vertically to the fourth vertical position so that the image acquisition device can focus on the first boundary of the lower module and acquire the image of the first boundary of the lower module; The detection stage is controlled to move horizontally so that the second boundary of the bond pair to be tested moves to below the objective lens of the image acquisition device, and the horizontal position of the detection stage at this time is recorded as the fourth horizontal position; the detection stage is controlled to move vertically to the first vertical position so that the image acquisition device focuses on the second boundary of the upper module and acquires the image of the second boundary of the upper module; With the detection platform in the fourth horizontal position, control the detection platform to move vertically to the second vertical position so that the image acquisition device focuses on the second boundary of the lower module and acquires the image of the second boundary of the lower module.

[0076] S302: Based on the first boundary image of the upper module and the first boundary image of the lower module, determine the first boundary offset of the bonding pair corresponding to the first boundary; based on the second boundary image of the upper module and the second boundary image of the lower module, determine the second boundary offset of the bonding pair corresponding to the second boundary.

[0077] Specifically, this step can be referred to as step S102.

[0078] S303: Based on the first boundary offset and the second boundary offset, obtain the second measured offset of the upper module and the lower module on the first radial direction X-axis at this time.

[0079] Specifically, the second measurement offset ShiftX 180 The calculation formula is: ShiftX 180 =(ShiftX 180-left -ShiftX 180-right ) / 2 Among them, ShiftX 180-left For the first boundary offset in step S302, ShiftX 180-right This is the second boundary offset in step S302.

[0080] S4: Based on the first and second measurement offsets, calculate the corrected offset ShiftX of the bond pair under test in the first radial direction, i.e., ShiftX = (ShiftX0 - ShiftX) / (ShiftX0 - ShiftX0). 180 ) / 2.

[0081] Wherein, the first radial direction X-axis is parallel to the first horizontal direction.

[0082] In a preferred embodiment, the first horizontal direction passes through the axis of the bond pair to be tested, that is, the first boundary and the second boundary are two radially opposite boundaries of the bond pair to be tested.

[0083] S5: Rotate the bond pair to be tested by 90 degrees so that the second radial direction in the bond pair to be tested, which is perpendicular to the first horizontal direction, is rotated to be parallel to the first horizontal direction.

[0084] Specifically, the test stage is driven to rotate 90 degrees axially by the rotary drive component in the drive device, so that the bond pair to be tested is rotated 90 degrees.

[0085] S6: Repeat steps S1-S4 to obtain the corrected offset ShiftY of the bond pair to be tested on the second radial direction Y-axis.

[0086] At this point, the first measurement offset obtained in the repeated step S1 is recorded as ShiftY0, and the second measurement offset obtained in the repeated step S3 is recorded as ShiftY. 180 Then the corrected offset in the second radial direction is ShiftY = (ShiftY0 - ShiftY0) / ( ... 180 ) / 2.

[0087] S7: Calculate the maximum offset Shift of the bond pair under test based on the corrected offset ShiftX in the first radial direction and the corrected offset ShiftY in the second radial direction. max .

[0088] Specifically, maximum offset .

[0089] In summary, the present invention provides a method and apparatus for measuring bond pair offset. By measuring the offset before and after rotating the bond pair 180 degrees, and calculating the offset of the bond pair in the first radial direction using the offsets obtained from the two measurements, the measurement error caused by incorrect boundary definition can be eliminated, thus improving the accuracy of bond pair offset measurement. By rotating the bond pair in the second radial direction by 90 degrees and then measuring the offset before and after rotating 180 degrees, the offset in the second radial direction can be obtained. Based on the offsets in the mutually perpendicular first and second radial directions, and using the Pythagorean theorem, the maximum offset of the bond pair in the second radial direction can be obtained, and the calculation error of the maximum offset can be reduced. By acquiring boundary images of the upper and lower modules in the bond pair in the diameter direction, and analyzing the boundary images of the upper and lower modules at the same boundary, the offset of the upper and lower modules at the same boundary can be quickly obtained. Based on the offsets of the upper and lower modules at the opposite boundaries, the offset of the bond pair in the diameter direction can be calculated. By acquiring boundary images of the upper and lower modules at the same horizontal position, the fused image obtained when these boundary images are subsequently overlaid accurately reflects the relative positional relationship between the upper and lower modules, thus ensuring the accuracy of the offset measurement. By overlaying the boundary images of the upper and lower modules at the same boundary, the offset of the upper and lower modules at that boundary can be quickly calculated through image analysis, thereby improving measurement efficiency.

[0090] In the embodiments provided in this application, it should be understood that the disclosed methods, apparatuses, computer-readable storage media, and electronic devices can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple components or modules may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices, components, or modules may be electrical, mechanical, or other forms.

[0091] The components described as separate parts may or may not be physically separate. The components shown as components may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the components can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each component can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0093] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0096] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for measuring the offset of a bond pair, wherein the bond pair comprises an upper module and a lower module bonded to each other, characterized in that, include: (1) Obtain images of the two boundaries of the upper and lower modules in the bond pair to be tested in the first horizontal direction respectively, and determine the offset of the upper and lower modules in the first horizontal direction at this time based on the images, which is recorded as the first measurement offset; (2) Rotate the bond pair to be tested by 180 degrees; (3) Repeat step (1) and record the offset determined in this step as the second measurement offset; (4) Subtract the second measurement offset from the first measurement offset and take half of it to obtain the corrected offset ShiftX of the bond pair to be tested in the first radial direction; wherein the first radial direction is parallel to the first horizontal direction.

2. The method for measuring bond pair offset according to claim 1, characterized in that, Also includes: (5) Rotate the bond pair to be tested by 90 degrees so that the second radial direction in the bond pair to be tested, which is perpendicular to the first horizontal direction, is rotated to be parallel to the first horizontal direction; (6) Repeat steps (1) to (4) again to obtain the corrected offset ShiftY of the bond pair to be tested in the second radial direction; (7) Calculate the maximum offset of the bond pair to be tested based on the corrected offset ShiftX in the first radial direction and the corrected offset ShiftY in the second radial direction.

3. The method for measuring bond pair offset according to claim 1, characterized in that, Step (1) includes: (11) Obtain the images of the first boundary and the second boundary of the upper module in the first horizontal direction, and the images of the first boundary and the second boundary of the lower module in the first horizontal direction, respectively, and record them as the first boundary image of the upper module, the second boundary image of the upper module, the first boundary image of the lower module, and the second boundary image of the lower module; (12) Based on the first boundary image of the upper module and the first boundary image of the lower module, determine the first boundary offset of the bonding pair corresponding to the first boundary; based on the second boundary image of the upper module and the second boundary image of the lower module, determine the second boundary offset of the bonding pair corresponding to the second boundary; (13) Based on the first boundary offset and the second boundary offset, the first measured offset of the upper module and the lower module in the first horizontal direction is obtained.

4. The method for measuring bond pair offset according to claim 3, characterized in that, The bond pair to be tested is supported on the testing stage, which is used to move the bond pair to be tested and rotate it around the vertical axis, so that any boundary of the upper and lower modules in any radial direction can be moved to the focusing area below the objective lens in the image acquisition device.

5. The method for measuring bond pair offset according to claim 4, characterized in that, Step (11) includes: With the detection platform at the same horizontal position, the first boundary image of the upper module and the first boundary image of the lower module are acquired respectively; With the detection platform at the same horizontal position, the second boundary image of the upper module and the second boundary image of the lower module are acquired respectively.

6. The method for measuring bond pair offset according to claim 5, characterized in that, The step (11) includes: when acquiring the first boundary image of the upper module, the first boundary image of the lower module, the second boundary image of the upper module and the second boundary image of the lower module, respectively recording the vertical position of the detection platform, and respectively recording it as the first vertical position, the second vertical position, the third vertical position and the fourth vertical position; Step (3) includes: controlling the detection stage to move to the first vertical position to acquire the second boundary image of the upper module; controlling the detection stage to move to the third vertical position to acquire the first boundary image of the upper module; controlling the detection stage to move to the second vertical position to acquire the second boundary image of the lower module; and controlling the detection stage to move to the fourth vertical position to acquire the first boundary image of the lower module.

7. The method for measuring bond pair offset according to claim 3, characterized in that, Step (12) includes: The first boundary image of the upper module and the first boundary image of the lower module are superimposed to obtain a first fused image, and the first boundary offset is determined based on the pixel distance between the first boundary of the upper module and the first boundary of the lower module in the first fused image. The second boundary image of the upper module and the second boundary image of the lower module are superimposed to obtain a second fused image. The second boundary offset is determined based on the pixel distance between the second boundary of the upper module and the second boundary of the lower module in the second fused image.

8. The method for measuring bond pair offset according to claim 4, characterized in that, The image acquisition device includes two objective lenses, which are arranged at intervals along the first horizontal direction and are used to capture images of the two boundaries of the upper and lower modules of the bonding pair under test in any radial direction.

9. A device for measuring bond pair offset, characterized in that, include: The testing station is used to support and fix the bond pair to be tested; An image acquisition device includes an objective lens, the image acquisition device being used to acquire images within the field of view of the objective lens; A driving device is connected to the testing station and includes a moving driving component and a rotating driving component connected to each other; the rotating driving component is used to drive the testing station to rotate the bond pair under test around a vertical axis, and the moving driving component is used to drive the testing station to move the bond pair under test. The control module is electrically connected to the image acquisition device and the driving device; The control module includes a processor and a storage module. The storage module stores one or more operation instructions, which can be executed by the processor to implement the bond pair offset measurement method as described in any one of claims 1-8.

10. The measuring device according to claim 9, characterized in that: The objective lens is provided in two parts, and the two objective lenses are arranged at intervals along the first horizontal direction.

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