CN117270291A - Enhanced line scanning camera and angle correction method thereof - Google Patents

Abstract

The invention provides an enhanced linear scanning camera and an angle correction method thereof, wherein the linear scanning camera comprises a camera main body, a light path component and a turntable component communicated between the camera main body and the light path component; the rotary table assembly comprises a stator component, a first rotor component and a second rotor component, wherein the stator component is fixedly connected with the optical path assembly, the first rotor component is fixedly connected with the camera main body, the first rotor component and the second rotor component can rotate relative to the stator component, and an operable first locking piece is arranged between the first rotor component and the second rotor component; the stator component, the first rotor component and the second rotor component are further provided with coaxial through holes so as to form an optical path channel between the camera main body and the optical path component, the outer peripheral surface of the first rotor component is provided with a handle, the outer peripheral surface of the second rotor component is provided with a protruding part, and the outer peripheral surface of the stator component is provided with a micro head component matched with the protruding part. The invention can realize the accurate adjustment of the installation angle of the linear scanning camera.

Description

Enhanced line scanning camera and angle correction method thereof

Technical Field

The invention relates to the technical field of wafer detection, in particular to an enhanced linear scanning camera and an angle correction method thereof.

Background

Semiconductors have been highly penetrated and fused into a variety of fields as strategic basic industries. In the manufacturing process of chips, a chip detection procedure is generally provided to find out the surface defects of the wafer in time in the manufacturing process and to improve the process in time, so that the yield of the wafer is improved.

Currently, a line scan camera (also referred to as a line scan camera) is typically used to detect defects on the wafer surface. A line scan camera is a camera using a line sensor. The photosensitive chip in the line scanning camera has a special shape, and its length is extremely long, for example, a length of several thousands of pixels, and its width is, for example, only one pixel. The line scanning camera is used for carrying out high-speed scanning by the line scanning camera in the occasion that the relative movement exists between the measured object and the camera, and the wafer just moves to the next unit length after one line is scanned each time, so that the scanning of the next line is continued.

In the process of detecting the wafer, the wafer is placed on a moving table, and a line scanning camera is triggered by the moving table at high frequency to perform continuous line scanning in the travelling process. In this process, the installation angle of the line scanning camera with respect to the moving stage needs to be strictly controlled. Specifically, the installation angle of the line scan camera determines the target surface (line) direction, the line scan direction is determined by the motion stage, and the target surface direction and the line scan direction must be orthogonal, if there is an angular deviation, the line scan imaging will be distorted.

The corner interface of the existing line scanning camera is usually an adjusting interface of a jackscrew matched with a conical surface, the interface can be manually rotated by loosening the jackscrew, and the jackscrew is fastened after the jackscrew is rotated in place. However, it is difficult to precisely adjust the installation angle of the line scan camera.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an enhanced wire sweep camera and an angle correction method thereof, so as to achieve precise adjustment of the installation angle of the wire sweep camera.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect, the present invention provides an enhanced linear scanning camera comprising a camera body, an optical path assembly, and a turret assembly in communication between the camera body and the optical path assembly;

the turntable assembly comprises a stator component, a first rotor component and a second rotor component, wherein the stator component is fixedly connected with the optical path assembly, the first rotor component is fixedly connected with the camera body, the first rotor component and the second rotor component are configured to rotate relative to the stator component, and an operable first locking piece is arranged between the first rotor component and the second rotor component;

wherein the stator part, the first rotor part and the second rotor part further have coaxial through holes to form an optical path channel between the camera body and the optical path component, and a handle is arranged on the outer peripheral surface of the first rotor component, a protruding part is arranged on the outer peripheral surface of the second rotor component, and a micro-head assembly matched with the protruding part is arranged on the outer peripheral surface of the stator component.

Further, the micro head assembly includes:

a mount mounted on an outer peripheral surface of the stator member; and

and the differential head is arranged on one side of the mounting seat and is used for being matched with the protruding part.

Further, the micro-head assembly further comprises:

and the second locking piece is arranged on one side of the mounting seat far away from the differential head, so that the protruding part is positioned between the differential head and the second locking piece.

Further, the first rotor component is fixedly connected with the camera body through a camera interface;

the stator component is fixedly connected with the optical path component through an optical path component interface.

Further, the optical path component interface includes:

a flange plate fixedly connected with the stator component and provided with a flange hole in the middle; and

the connecting cylinder is connected between the flange plate and the light path component;

further, the connecting cylinder is in threaded connection with the light path component and can be locked by a locking nut.

Further, the first rotor member is rotatably coupled to the stator member by a bearing assembly.

Further, the second rotor component is sleeved on the first rotor component, and the first rotor component can rotate relative to the second rotor component.

Further, a scale is provided on the outer peripheral surface of the stator member, and scale marks are provided on the outer peripheral surface of the first rotor member.

In a second aspect, the present invention provides an angle correction method for the enhanced linear sweep camera, including:

acquiring two line scanning images obtained by continuous scanning of the line scanning camera;

splicing the two lines of scanning images to obtain a spliced image;

detecting whether the dislocation length between the two line scanning images exceeds a preset deviation threshold value or not based on the spliced images;

and when the dislocation length between the two line scanning images exceeds a preset deviation threshold, rotating the handle and the adjusting differential head assembly to adjust the angle of the camera main body, and returning to the step of obtaining the two line scanning images obtained by continuous scanning of the line scanning camera until the dislocation length between the two line scanning images is within the preset deviation threshold.

By adopting the technical scheme, the invention has the following beneficial effects:

the invention adds a rotary table assembly between the camera main body and the light path assembly, and the rotary table assembly comprises a stator component, a first rotor component and a second rotor component, wherein the first rotor component and the second rotor component are configured to rotate relative to the stator component, a handle is arranged on the first rotor component, a protruding part is arranged on the second rotor component, a micro head assembly matched with the protruding part is arranged on the stator component, and an operable locking piece is arranged between the first rotor component and the second rotor component. Therefore, when the installation angle (namely the extending direction of the target surface) of the camera body needs to be adjusted, the first locking piece can be unscrewed first, and the handle is rotated to drive the camera body to rotate by rotating the first rotor component, so that the rough adjustment of the angle of the camera body is realized; and then the first locking piece is screwed down, and the micro head assembly is regulated, so that the micro head assembly drives the protruding part to rotate, and further drives the second rotor component and the first rotor component to rotate.

Drawings

FIG. 1 is a schematic view of an enhanced line scanning camera according to the present invention;

FIG. 2 is an exploded view of the enhanced line scan camera of the present invention;

FIG. 3 is a schematic view of the turntable in the present invention;

FIG. 4 is an image scanned when the target surface direction of the line scan camera is orthogonal to the line scan direction;

fig. 5 is an image scanned when the target surface direction of the line scan camera is not orthogonal to the line scan direction.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

Aiming at the problem that the installation angle of a line scanning camera cannot be accurately adjusted in the prior art, the invention provides an enhanced line scanning camera. As shown in fig. 1 to 3, the line scanning camera includes a camera body 1, an optical path assembly 2, and a high precision turret assembly 3 communicating between the camera body 1 and the optical path assembly 2. In the process of inspecting a wafer, the line scanning camera is located above a moving table (not shown) and the optical path component 2 thereof is fixed, the wafer is placed on the moving table, and the moving table is triggered by high frequency to perform continuous line scanning in the travelling process. In this process, the installation angle of the line scanning camera with respect to the moving stage needs to be strictly controlled. Specifically, the mounting angle of the camera body 1 determines the target surface direction (i.e., X direction), the line scan direction (i.e., the traveling direction: Y direction) is determined by the motion stage, and the target surface direction and the line scan direction must be orthogonal, and if there is an angular deviation, the line scan image will be distorted. The turntable assembly 3 in the present invention is used to adjust the mounting angle of the camera body 1, i.e., the target surface direction.

In the present invention, the turntable assembly 3 comprises a stator member 31 in the form of a plate, and a first rotor member 32 and a second rotor member 33 in the form of a plate. Wherein the stator part 31 is fixedly connected with the light path assembly 2, the first rotor part 32 is fixedly connected with the camera body 1, and the second rotor part 33 is arranged between the first rotor part 32 and the stator part 31. The first rotor part 32 and the second rotor part 33 are each configured to be rotatable relative to the stator part 31, and an operable first locking member 36 is provided between the first rotor part 32 and the second rotor part 33, wherein the first locking member 36 is, for example, a jackscrew.

As shown in fig. 3, the stator member 31, the first rotor member 32, and the second rotor member 33 further have coaxial through holes to form an optical path channel between the camera body 1 and the optical path component 2, and the first rotor member 32 has a handle 34 on its outer peripheral surface, the second rotor member 33 has a projection 35 on its outer peripheral surface, and the stator member 31 has a micro head component fitted with the projection 35 on its outer peripheral surface.

In the present invention, a micro head assembly includes: the stator member 31 includes a mount 371 mounted on an outer peripheral surface of the stator member 31, a differential head 372 mounted on a side of the mount 371, and a second lock 373 mounted on a side of the mount 371 remote from the differential head 372. The protruding portion 35 is located between the differential head 372 and the second locking member 373, and the differential head 372 is configured to cooperate with the protruding portion 35, and the protruding portion 35 can be pushed to rotate by adjusting the differential head 372, so as to drive the second rotor member 33 to rotate. The second locking member 373 and the differential head 372 are provided on opposite sides of the protruding portion 35, respectively, and can be locked by the second locking member 373 when the protruding portion 35 is turned into place.

In the present invention, the first rotor member 32 is fixedly connected to the camera body 1 through a camera interface; the stator component 31 is fixedly connected with the optical path component 2 through an interface of the optical path component 2. The optical path assembly 2 interface may include: a flange plate 21 fixedly connected with the stator member 31 and provided with a flange hole in the middle; and a connection cylinder 22 connected between the flange 21 and the optical path assembly 2. The flange hole and the inner hole of the connecting tube 22 are coaxial with the through holes of the stator member 31, the first rotor member 32, and the second rotor member 33.

In the present invention, the introduction of the turret assembly 3 may affect the focal length of the imaging objective lens located at the bottom end of the optical path assembly 2, so that the connecting barrel 22 is screwed with the optical path assembly 2 to adjust the objective lens to a desired focal plane; when adjusted in place, the light path assembly 2 can be locked with the connecting cylinder 22 by a lock nut 23.

In one embodiment, the first rotor member 32 may be rotatably coupled to the stator member 31 by a bearing assembly (not shown). Further, as shown in fig. 4, the lower end of the second rotor member 33 has a circumferential receiving groove for receiving the second rotor member 33, so that the second rotor member 33 is fitted over the receiving groove of the first rotor member 32. When the first locking member is locked, the first rotor member 32 and the second rotor member 33 are fixed together; when the first locking member is unlocked, the first rotor member 32 is in turn able to rotate relative to the second rotor member 33.

In an embodiment, the outer peripheral surface of the stator part 31 is provided with a dial 38, and the outer peripheral surface of the first rotor part 32 is provided with graduation marks (not shown) cooperating with the dial 38, thereby providing a reference basis for the rotation of the first rotor part 32.

When the installation angle (i.e., the target surface extending direction) of the camera body 1 needs to be adjusted, the first locking piece 36 can be unscrewed first, and the handle 34 can be rotated to drive the camera body 1 to rotate by rotating the first rotor component 32, so that rough adjustment of the angle of the camera body 1 can be realized; then, the first locking piece 36 is screwed down again, and the micro-head assembly is adjusted, so that the protrusion 35 is driven to rotate by the micro-head assembly, and the second rotor component 33 and the first rotor component 32 are driven to rotate, and the precision of the micro-head assembly is high, so that the fine adjustment of the installation angle of the camera body 1 can be realized, and the accuracy of the installation angle of the line scanning camera is improved.

In addition, the invention also provides an angle correction method for the enhanced line scanning camera, which specifically comprises the following steps:

s1, acquiring two line scanning images obtained by continuous scanning of a line scanning camera.

Specifically, when the target surface direction of the camera body 1 is orthogonal to the line scanning direction, a scanned image as shown in fig. 4 can be obtained; when the two images are not orthogonal, the obtained scanned image is tilted at the same angle as shown in fig. 5. It should be understood that in practice the image tilt angle is small and that fig. 5 is only for display effect, the tilt angle is increased.

S2, splicing the two lines of scanning images obtained in the step S1 to obtain a spliced image.

In practice, the inclination angle of the image is very small, and for a single-line scanning image, the inclination angle is difficult to detect, so that the two-line scanning images are spliced together to obtain a spliced image.

S3, detecting whether the dislocation length between the two line scanning images exceeds a preset deviation threshold value based on the spliced images.

Specifically, when the misalignment length between the two line scan images exceeds a predetermined misalignment threshold, for example, 1 pixel length, misalignment between the two line scan images is considered to occur. As shown in fig. 5, the misalignment length here refers to a deviation D in the linear scanning direction (X direction) of the start position of the bottom end of the first line scan image from the start position of the top end of the second line scan image.

In fig. 5, the first line scan image and the second line scan image have a displacement length D therebetween, and if D exceeds a predetermined displacement threshold, the first line scan image and the second line scan image are considered to be displaced. Wherein, when measuring the dislocation length, can be through zooming in the spliced image and measure.

And S4, when the dislocation length between the two line scanning images exceeds a preset deviation threshold, rotating the handle 34 and adjusting the micro head assembly to adjust the angle of the camera body 1, and then repeatedly executing the steps until the dislocation length between the two line scanning images is within the preset deviation threshold.

Optionally, when the handle 34 is turned and the micro head assembly is adjusted to adjust the angle of the camera body 1 in step S4, the target turning angle of the camera body 1 may be obtained based on the offset length between the two line scan images, and then the handle 34 is turned and the micro head assembly is adjusted according to the target turning angle, so as to adjust the angle of the camera body 1.

Through the above steps, the target surface direction of the camera body 1 can be quickly and accurately adjusted to be orthogonal to the line scanning direction.

In the present invention, the aforementioned predetermined deviation threshold value determines the minimum adjustment amount of the turntable. For example, for a line scan camera with a target length L of 6K pixels, where the predetermined deviation threshold is 1 pixel, the tilt angle of the image is arcsin (1/6000) =0.0096 degrees=34.5 seconds, and on this basis, the minimum adjustment amount of the turntable is at least less than half the angle.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.

Claims (10)

1. The enhanced line scanning camera is characterized by comprising a camera body, an optical path component and a turntable component communicated between the camera body and the optical path component;

the turntable assembly comprises a stator component, a first rotor component and a second rotor component, wherein the stator component is fixedly connected with the optical path assembly, the first rotor component is fixedly connected with the camera body, the first rotor component and the second rotor component are configured to rotate relative to the stator component, and an operable first locking piece is arranged between the first rotor component and the second rotor component;

wherein the stator part, the first rotor part and the second rotor part further have coaxial through holes to form an optical path channel between the camera body and the optical path component, and a handle is arranged on the outer peripheral surface of the first rotor component, a protruding part is arranged on the outer peripheral surface of the second rotor component, and a micro-head assembly matched with the protruding part is arranged on the outer peripheral surface of the stator component.

2. The enhanced wire sweep camera of claim 1 wherein said micro head assembly comprises:

a mount mounted on an outer peripheral surface of the stator member; and

and the differential head is arranged on one side of the mounting seat and is used for being matched with the protruding part.

3. The enhanced wire sweep camera of claim 2 wherein said micro head assembly further comprises:

and the second locking piece is arranged on one side of the mounting seat far away from the differential head, so that the protruding part is positioned between the differential head and the second locking piece.

4. The enhanced wire sweep camera of claim 1 wherein said first rotor member is fixedly connected to said camera body through a camera interface;

the stator component is fixedly connected with the optical path component through an optical path component interface.

5. The enhanced wire sweep camera of claim 1 wherein said optical path assembly interface comprises:

a flange plate fixedly connected with the stator component and provided with a flange hole in the middle; and

and the connecting cylinder is connected between the flange plate and the light path component.

6. The enhanced line broom camera of claim 5 wherein said connector barrel is threadably connected to said light path assembly and is lockable by a lock nut.

7. The enhanced wire sweep camera of claim 1 wherein said first rotor member is rotatably connected to said stator member by a bearing assembly.

8. The enhanced wire sweep camera of claim 7 wherein said second rotor member is sleeved on said first rotor member and said first rotor member is rotatable relative to said second rotor member.

9. The enhanced wire sweep camera of claim 1 wherein the outer peripheral surface of said stator member is provided with a dial and the outer peripheral surface of said first rotor member is provided with graduation marks.

10. An angle correction method for an enhanced line scanning camera as claimed in any one of the preceding claims 1-9, comprising:

acquiring two line scanning images obtained by continuous scanning of the line scanning camera;

splicing the two lines of scanning images to obtain a spliced image;

detecting whether the dislocation length between the two line scanning images exceeds a preset deviation threshold value or not based on the spliced images;

and when the dislocation length between the two line scanning images exceeds a preset deviation threshold, rotating the handle and the adjusting differential head assembly to adjust the angle of the camera main body, and returning to the step of obtaining the two line scanning images obtained by continuous scanning of the line scanning camera until the dislocation length between the two line scanning images is within the preset deviation threshold.