Compensation method for zooming image capturing offset of image capturing device

Abstract

The present application relates to a zooming offset compensation method for an image capturing device, comprising: a providing step, providing a jig, the first focus line and the second focus line of the jig having a difference; a first measuring step, taking two images by focusing on the first focus line and the second focus line respectively to obtain a first offset vector; a rotating step, rotating the jig; a second measuring step, taking two images by focusing on the height of the first focus line and the second focus line respectively to obtain a second offset vector; a calculating step, obtaining a zooming offset vector according to the first offset vector, the second offset vector and the rotating angle; and a compensation step, compensating the image capturing device with the zooming offset vector.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of image capturing device, and particularly discloses a method for compensating zooming image capturing deviation of an image capturing device. BACKGROUND

[0002] An image capturing device is a photosensitive electronic device including CCD and CMOS, which is used to capture images and generate digital images. In the electronic field, after die bonding, the image capturing device can be used to determine the actual die bonding position.

[0003] Since the height of the chip is greater than the depth of field of the lens of the image capturing device, the die bonding deviation cannot be calculated by a single image capturing result. Therefore, the image capturing device needs to capture images twice by adjusting the focal length to the substrate and the upper surface of the chip. However, as shown in Figure 1a and Figure 1b , during the adjustment of the focal length of the image capturing device, there is a zooming image capturing deviation due to structural errors, that is, the two captured images are not at the same position, so that the die bonding position of the chip cannot be accurately determined.

[0004] In the prior art, the zooming image capturing deviation of the image capturing device is measured by using a concentric circle jig with a step as shown in Figure 2a . As shown in Figure 2b , the image capturing device captures two circle centers of the concentric circle jig at different focal length positions. The difference between the two circle centers is the zooming image capturing deviation. However, the concentric circle jig will have errors during processing, so that the jig is not a perfect concentric circle. In this case, the zooming image capturing deviation measured by the prior art method will include the processing error, so that the die bonding position of the chip cannot be accurately determined. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a method for compensating the zooming image capturing deviation of an image capturing device, which does not need to consider the error caused by jig processing, and can compensate the zooming image capturing deviation caused by structural errors during the adjustment of the focal length of the image capturing device.

[0006] The present application provides a zooming image device offset compensation method, comprising: providing a jig, the jig having a first focus line and a second focus line, the first focus line being located at a first height position and the second focus line being located at a second height position, the first focus line and the second focus line having a distance, and the second focus line being located at the periphery of the first focus line; first measuring, taking images of the first focus line and the second focus line by focusing the image device at the first height position and the second height position respectively, and obtaining a first offset vector between a first center position of the first focus line and a second center position of the second focus line; rotating, rotating the jig with a jig rotation center to form a rotation angle; second measuring, taking images of the first focus line and the second focus line by focusing the image device at the first height position and the second height position respectively, and obtaining a second offset vector between the first center position of the first focus line and the second center position of the second focus line; calculating, obtaining a zooming offset vector corresponding to the first height position and the second height position by the image device according to the first offset vector, the second offset vector and the rotation angle; and compensating, compensating the image device by the zooming offset vector.

[0007] In an embodiment of the present application, the actual first center position of the first focus line and the actual second center position of the second focus line are offset.

[0008] In an embodiment of the present application, the first focus line and the second focus line are circular.

[0009] In an embodiment of the present application, the first focus line and the second focus line are square.

[0010] In an embodiment of the present application, the rotation angle is 180 degrees, and the zooming offset vector is an average vector of the first offset vector and the second offset vector.

[0011] In an embodiment of the present application, the jig rotation center overlaps the actual first center position, or the jig rotation center overlaps the actual second center position.

[0012] The zoom image acquisition offset compensation method of the image acquisition device of the present invention uses technical means to obtain the first offset vector and the rotation angle of the second offset vector through two measurement steps before and after the rotation step. Since the zoom image acquisition offset vector caused by adjusting the focal length does not change before and after the rotation of the fixture, but the vector of the deviation of the two center positions of the fixture changes, even if the two center positions of the fixture are deviated (whether due to processing errors or intentional deviation), the zoom image acquisition offset vector can be separated without knowing the actual deviation vector of the two center positions of the fixture. Attached Figure Description

[0013] Figure 1a This is a schematic diagram of the image capturing device of the present invention adjusting the focal length under ideal conditions.

[0014] Figure 1b This is a schematic diagram illustrating how the image capturing device of the present invention adjusts the focal length under actual conditions with structural errors.

[0015] Figure 2a This is a side view cross-sectional schematic diagram of a concentric circular fixture with stepped edges used in the prior art to measure zoom image shift.

[0016] Figure 2b This is a top view schematic diagram of the zoom image shift obtained by the imaging device at different focal length positions when imaging a concentric circular fixture in the prior art.

[0017] Figure 3 This is a block diagram illustrating a method for compensating for zoom image capture offset in an image capturing device according to an embodiment of the present invention.

[0018] Figure 4a This is a top view schematic diagram of the fixture for the compensation method of zoom image acquisition offset of the image acquisition device according to this embodiment of the present invention.

[0019] Figure 4b This is a top view of the center offset vector, the first offset vector, and the zoom offset vector relative to the fixture in the first measurement step of the zoom image acquisition offset compensation method of the imaging device in this embodiment of the present invention.

[0020] Figure 4c This is a top view of the center offset vector, the second offset vector, and the zoom offset vector relative to the fixture in the second measurement step of the zoom image acquisition offset compensation method of the imaging device in this embodiment of the present invention.

[0021] Figure 5 This is a top view of the center offset vector, first offset vector, second offset vector, and zoom offset vector of the image acquisition device zoom image acquisition offset compensation method of this embodiment of the present invention before and after rotating 180 degrees.

[0022] Figure 6The aforementioned vectors of the image capturing device zooming offset compensation method of this embodiment of the present application are shown in the top view before and after rotation at other rotation angles.

[0023] Reference numerals

[0024] 100 Image capturing device zooming offset compensation method

[0025] 1 Jig

[0026] 11 First focusing surface

[0027] 111 First focusing line

[0028] 111p First center position

[0029] 111a Actual first center position

[0030] 12 Second focusing surface

[0031] 121 Second focusing line

[0032] 121p Second center position

[0033] 121a Actual second center position

[0034] Zooming offset vector

[0035] C Image capturing device

[0036] Center offset vector

[0037] First offset vector

[0038] Center offset vector

[0039] Second offset vector

[0040] S1 Providing step

[0041] S2 First measuring step

[0042] S3 Rotating step

[0043] S4 Second measuring step

[0044] S5 Calculating step

[0045] S6 Compensating step DETAILED DESCRIPTION

[0046] The following is according to Figures 3 to 6This description illustrates one embodiment of the present invention. It is not intended to limit the scope of the invention, but rather to provide one possible embodiment.

[0047] like Figure 3 As shown, the zoom image acquisition offset compensation method 100 of the image acquisition device according to an embodiment of the present invention is performed in sequence as follows: providing step S1, first measurement step S2, rotation step S3, second measurement step S4, calculation step S5, and compensation step S6.

[0048] like Figure 3 and Figure 4a As shown, in step S1, a fixture 1 is provided. The fixture 1 has a first focusing surface 11 and a second focusing surface 12 for focusing by the focusing system of the image capturing device C. The first focusing surface 11 is located at a first height position. The second focusing surface 12 is located at a second height position. Preferably, the difference between the first height position and the second height position is equal to the difference between the substrate and the top surface of the chip. In this embodiment, the first height position is lower than the second height position, forming a structure with a higher periphery. Of course, in other embodiments, the first height position may also be higher than the second height position, forming a structure with a lower periphery.

[0049] like Figure 4a As shown, the first focusing surface 11 has a first focusing line 111, which is located at a first height position. The second focusing surface 12 has a second focusing line 121, which is located at a second height position. The second focusing line 121 is located outside the first focusing line 111. The first focusing line and the second focusing line are located at different height positions with a distance between them.

[0050] In this embodiment, both the first focusing line 111 and the second focusing line 121 are circular to facilitate the determination of the center position of the first focusing line 111, the actual center position of the second focusing line 121, and the center position in the image captured by the imaging device. In other embodiments, the first focusing line 111 and the second focusing line 121 may also be symmetrical shapes such as square or cross, and the shapes of the first focusing line 111 and the second focusing line 121 may also be different.

[0051] In this embodiment, the actual first center position of the first focusing line is deviated from the actual second center position of the second focusing line. This deviation may be due to processing errors or intentional.

[0052] In the first measurement step S2, the imaging device C focuses on the first height position and the second height position respectively to capture images of the first focusing line 111 and the second focusing line 121 twice, and obtains the first offset vector between the first center position 111p of the first focusing line 111 and the second center position 121p of the second focusing line 121 in the two image captures.

[0053] Among them, such as Figure 4b As shown, the first center position 111p refers to the corresponding position of the image obtained when the actual first center position 111a is focused on the first height position by the imaging device C. The second center position 121p refers to the corresponding position of the image obtained when the actual second center position 121a is focused on the second height position by the imaging device C. The vector between the actual first center position 111a and the actual second center position 121a is the center offset vector. First offset vector That is, the center offset vector Plus zoom offset vector Right now At this time, the center offset vector and zoom offset vector It still cannot be obtained directly.

[0054] In rotation step S3, the fixture 1 is rotated around its rotation center to form a rotation angle. The rotation angle is a non-zero angle. In this embodiment, the fixture rotation center overlaps with the actual second center position 121a, so that the actual second center position 121a and the second center position 121p are in the same position before and after rotation. Of course, in other embodiments, the fixture rotation center may also overlap with the actual first center position 111a, so that the actual first center position 111a and the first center position 111p are in the same position before and after rotation, or the fixture rotation center may not overlap with either the first center position 111p or the second center position 121p.

[0055] In the second measurement step S4, the imaging device C focuses on the first height position and the second height position respectively to capture images of the first focusing line 111 and the second focusing line 121 twice, and obtains the second offset vector between the first center position 111p of the first focusing line 111 and the second center position 121p of the second focusing line 121 in the two image captures.

[0056] Since the second measurement step S4 occurs after the rotation step S3, at least one of the first center position 111p and the second center position 121p will be displaced compared to the first measurement step S2. Therefore, the second offset vector... With the first offset vector For different reasons.

[0057] At this time, as Figure 4c As shown, the vector between the actual first center position 111a and the actual second center position 121a is the center offset vector. Second offset vector That is, the center offset vector Plus zoom offset vector Right now

[0058] In calculation step S5, based on the first offset vector The second offset vector The rotation angle is derived from the following mathematical formulas 1 and 2, which yield the zoom offset vector obtained by the imaging device zooming at the first height position and the second height position.

[0059] Mathematical formula 1:

[0060] Mathematical formula 2:

[0061] Where [R] is the rotation matrix corresponding to the rotation angle of the fixture. as well as Given that the results of the first measurement step S2 and the second measurement step S4 are known, the zoom offset vector can be obtained.

[0062] Because of the zoom offset vector generated by adjusting the focal length before and after the rotation of fixture 1. It will not change, but the two center offset vectors The direction changes, so even if the two center positions of the fixture are offset (whether due to machining errors or intentional deviations), the zoom offset vector can still be isolated.

[0063] In the aforementioned rotation step S3, as Figure 5 As shown, the optimal rotation angle is 180 degrees. This can be determined through mathematical formula 2. Zoom offset vector That is, the first offset vector With the second offset vector The average vector. Of course, the zoom image acquisition offset compensation method 100 of the imaging device of the present invention is not limited to application to a 180-degree rotation. For example... Figure 6 As shown, the zoom image acquisition offset compensation method 100 of the image acquisition device of the present invention can be applied to any angle with non-zero rotation.

[0064] In the compensation step S6, when the focus of the imaging device C is respectively aligned to the substrate and the chip upper surface to take images, the zoom offset vector The imaging device C is compensated.

[0065] The above description and explanation is only for the preferred embodiments of the present application, and those skilled in the art can make other modifications according to the above defined protection scope and the above explanation, but these modifications should still be within the protection scope of the present application.

[0066] In this specification, the present application has been described with reference to its particular embodiments. It is clear, however, that various modifications and changes can be made without departing from the spirit and scope of the present application. Therefore, the specification and drawings should be considered as illustrative and not restrictive.

Claims

1. A method for compensating for zooming image shift of an image capturing device, characterized by, The compensation method comprises: a providing step of providing a jig having a first focus line and a second focus line, the first focus line being located at a first height position and the second focus line being located at a second height position, the first focus line and the second focus line having a difference therebetween, the second focus line being located at the periphery of the first focus line, the actual first center position of the first focus line and the actual second center position of the second focus line being deviated; a first measuring step of taking images of the first focus line and the second focus line by focusing the image taking device on the first height position and the second height position respectively, and obtaining a first offset vector between the first center position of the first focus line and the second center position of the second focus line in the two images; a rotating step of rotating the jig with a jig rotation center to form a rotation angle; a second measuring step of taking images of the first focus line and the second focus line by focusing the image taking device on the first height position and the second height position respectively, and obtaining a second offset vector between the first center position of the first focus line and the second center position of the second focus line in the two images; a calculating step of obtaining a zooming offset vector generated by zooming the image taking device corresponding to the first height position and the second height position according to the first offset vector, the second offset vector and the rotation angle; a compensating step of compensating the image taking device according to the zooming offset vector. The first focus line and the second focus line are circular.

2. The method of claim 1, wherein the method further comprises: The first focus line and the second focus line are square.

3. The method of claim 1, wherein the method further comprises: The rotation angle is 180 degrees, and the zooming offset vector is an average vector of the first offset vector and the second offset vector.

4. The method of claim 1, wherein the method further comprises: The jig rotation center overlaps the actual first center position, or the jig rotation center overlaps the actual second center position.

5. The method of claim 1, wherein the method further comprises: ​

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