Optical structure suitable for wafer product multi-defect detection
By combining a line scan camera and a multi-angle line light source, the problem of poor detection effect on surface unevenness and color difference of wafer products in traditional inspection methods has been solved, realizing efficient detection of a variety of defects and significantly improving inspection efficiency.
Patent Information
- Application Number
- CN202520167007.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-01-23
AI Technical Summary
When using traditional cameras with lenses to inspect wafer products, it is difficult to effectively detect surface defects and color differences, resulting in poor inspection results.
Employing a line scan camera and line scan light source, illumination is achieved by setting line light sources at different angles, including a first line light source (18°~22°), a second line light source (43°~47°), and a third line light source (67°~83°). Combined with dark field, light-dark angle, and bright field illumination functions, it enables the detection of various defects.
It improves the inspection effect of wafer products, and can simultaneously detect a variety of defects such as scratches, pin marks, bright spots, white spots, color differences, black spots and fixed point scratches, significantly improving the efficiency of the production line.
Smart Images
Figure CN223870521U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of semiconductor wafer optical detection, and particularly relates to an optical structure suitable for multi-defect detection of wafer products. BACKGROUND
[0002] Wafer defect detection refers to a technology of detecting wafer surface defects and recording defect positions and quantities. Wafer defect detection can discover problems in advance, and thus is widely applied. There are many types of defects that need to be detected on the wafer surface, such as scratches, pinhole abnormalities, bright spots, white spots, color differences, black spots, fixed point scratches, and scratch defects on the back of the wafer.
[0003] In the conventional technology, a camera is used in cooperation with a lens to directly detect wafer products. This method can only detect relatively obvious defects on the wafer products, and there is a problem of insufficient light for defects that cause the surface of the product to be concave-convex and color differences, which affects the detection effect. SUMMARY
[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide an optical structure suitable for multi-defect detection of wafer products, to solve the problem of poor detection light in the prior art that only uses a camera in cooperation with a lens to directly detect wafer products.
[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides an optical structure suitable for multi-defect detection of wafer products, comprising a line-scan camera and a line-scan lens mounted on the collection end of the line-scan camera.
[0006] The optical structure further comprises a line-scan light source, the line-scan light source comprises a first line light source, a second line light source, and a third line light source, and is used for wafer product detection illumination.
[0007] The first line light source has a first included angle between the outgoing light and the horizontal plane, and the angle of the first included angle is 18°-22°, which is used for detecting scratches and pinhole abnormalities on the surface of the wafer product.
[0008] The second line light source has a second included angle between the outgoing light and the horizontal plane, and the angle of the second included angle is 43°-47°, which is used for detecting color differences of the wafer product.
[0009] The third line light source has a third included angle between the outgoing light and the horizontal plane, and the angle of the third included angle is 67°-83°, which is used for detecting black spots and fixed point scratches on the wafer product.
[0010] In an embodiment of the utility model, the angle of the first included angle is 20°.
[0011] In an embodiment of the utility model, the angle of the second included angle is 45°.
[0012] In an embodiment of the utility model, the third included angle is 75 °.
[0013] In an embodiment of the utility model, the scanning width of the line scan camera is greater than the maximum width of the wafer product to be detected.
[0014] In an embodiment of the utility model, the first line light source, the second line light source and the third line light source are all strip structures.
[0015] In an embodiment of the utility model, two line scan cameras and two groups of line scan light sources are provided, the two line scan cameras are oppositely distributed, and the two groups of line scan light sources are mirror-symmetrically arranged between the two line scan cameras.
[0016] In an embodiment of the utility model, a detection table is provided, the detection table is horizontally placed, a rectangular frame is connected to the detection table, and the line scan camera and the line scan light source are both mounted on the frame.
[0017] As described above, the optical structure suitable for multi-defect detection of wafer products has the following beneficial effects:
[0018] The line scan light source is provided, the working principle of the line scan light source is to move a long and narrow light source quickly to scan light on a to-be-detected object, so as to obtain image data, the optical design of the line scan light source usually adopts a reflection type design, imaging is realized through a reflecting mirror, the size of the light source can be reduced and the imaging effect can be improved, the line scan light source is used in cooperation with the line scan camera and the line scan lens for detection, and the detection effect of the wafer can be improved.
[0019] The utility model discloses the exit light angle of the first line light source, the second line light source and the third line light source of the line scan light source is reasonably designed, and the dark field illumination function, the bright-dark included angle illumination function and the bright field illumination function are simultaneously constructed in the detection process, the dark field illumination function can be used for detecting defects such as wafer product surface scratch, pin scratch anomaly, bright spot and white spot, the bright-dark included angle illumination function can detect wafer product color difference defects, and the bright field illumination function can be used for detecting black spot and fixed point scratch defects on the wafer product, the utility model discloses a plurality of defect detection of wafer products can be realized at a time, the production line work efficiency is greatly improved, and excellent application effect is obtained in the market. ACCURACY
[0020] Fig. 1 The structure schematic diagram of the utility model is shown.
[0021] Fig. 2 The line scan light source and the horizontal plane included angle schematic diagram in the utility model are shown.
[0022] Element number explanation
[0023] Line scan camera 1; frame 11; line scan lens 2; first line light source 3; second line light source 4; third line light source 5; detection table 6; scanning width 7; first included angle a; second included angle b; third included angle c. DETAILED DESCRIPTION
[0024] The following specific embodiments illustrate the implementation of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosed content.
[0025] Please refer to Figs. 1-2 It should be understood that the structure, proportion, size, etc. shown in the drawings attached to the present specification are only used to cooperate with the disclosed content for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the disclosed technology. At the same time, the terms such as "up", "down", "left", "right", "middle" and "one" in the present specification are only for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present application.
[0026] Please refer to Figs. 1-2 The present application provides an optical structure suitable for multi-defect detection of wafer products, comprising a line scan camera 1 and a line scan lens 2 mounted on the collection end of the line scan camera 1; the scanning width 7 of the line scan camera 1 is greater than the maximum width of the wafer product detection area; it includes a line scan light source, which includes a first line light source 3, a second line light source 4, and a third line light source 5 for wafer product detection illumination 2; the first line light source 3, the second line light source 4, and the third line light source 5 are all strip structures; it includes a detection table 6, which is placed horizontally, and a rectangular frame 11 is connected to the detection table 6; the line scan camera 1 and the line scan light source are both mounted on the frame 11. In actual production line, the detection table 6 is mounted on the displacement module for use, which is composed of a base, a slide rail, a slide block, and a linear motor. The slide rail is mounted on the base, and the slide block is slidingly fitted on the slide rail. The detection table 6 is simultaneously mounted on the slide block and the linear motor. The linear motor drives the detection table 6 to slide through the slide block to realize displacement. The line scan camera 1, the line scan lens 2, and the line scan light source are synchronously matched to realize one-time comprehensive scanning detection of the entire wafer product detection area.
[0027] The utility model discloses a line sweep light source is set, and the working principle of line sweep light source is through the narrow light source of quick movement, and light is scanned on the object to be measured to obtain image data, and the optical design of line sweep light source usually adopts the design of reflection, and through the imaging of reflector, the size of light source can be reduced and the imaging effect is improved, and line sweep light source is used with line sweep camera 1 and line sweep lens 2, and the detection effect of wafer can be improved.
[0028] The line sweep camera 1 is equipped with two, and the line sweep light source is equipped with two groups, and the two line sweep cameras 1 are oppositely distributed, and the two groups of line sweep light sources are mirror-symmetrical between the two line sweep cameras 1, and the two line sweep cameras 1 are used with the two groups of line sweep light sources, and the double sides of wafer product can be detected simultaneously, and the detection efficiency is further improved.
[0029] The first line light source 3 is equipped with the first included angle a between the emergent light and the horizontal plane, and the angle of the first included angle a is 18~22 °, and is used for detecting the scratch, the needle mark anomaly, the bright spot, the white spot and the like on the surface of wafer product, and the emergent light of the first line light source 3 is an acute angle between the horizontal plane, and the dark field illumination function is constructed, and the scratch, the needle mark anomaly, the bright spot, the white spot and the like on the surface of wafer product will cause the concave-convex shape of product surface, according to the definition of optical triangle, and the acute angle oblique light source can form the concave-convex curved surface reflection into line sweep lens 2, so that the defect of this kind is displayed more obviously.
[0030] The second line light source 4 is equipped with the second included angle b between the emergent light and the horizontal plane, and the angle of the second included angle b is 43~47 °, and is used for detecting the color difference of wafer product, and the emergent light of the second line light source 4 is a right angle between the horizontal plane, and the bright-dark included angle illumination function is constructed, and the color difference of wafer product is caused by the cleaning and hot-pressing process of wafer, and leads to the discoloration of wafer product surface material, and the utility model discloses the method of bright-dark included angle irradiation, and the light path of line sweep lens 2 is received, and the product reflection is mostly dispersion angle, and the color difference contrast is enhanced, and the emergent light of the second line light source 4 is between the bright field and the dark field, and has good detection effect for the color difference of wafer and the back scratch.
[0031] The third line light source 5 is equipped with the third included angle c between the emergent light and the horizontal plane, and the angle of the third included angle c is 67~83 °, and is used for detecting the black point and the fixed point scratch on wafer product, and the emergent light of the third line light source 5 is an obtuse angle with the horizontal plane, and the bright field illumination function is constructed, and the black point and the fixed point scratch on wafer product are mostly caused by the front machining process, and the utility model discloses the bright field illumination mode close to vertical, and the defect characteristics of this kind can be highlighted.
[0032] The utility model discloses a reasonable design to the emergent light angle of the first line light source 3, the second line light source 4, the third line light source 5 of constituting line sweep light source, simultaneously constructs dark field illumination function, bright and dark angle illumination function, bright field illumination function in the detection process, and the dark field illumination function can be used for the detection of wafer product surface scratch, pin mark abnormality, bright spot, white spot and other defects, the bright and dark angle illumination function can be the detection of wafer product chromatic aberration defect, and the bright field illumination function can be used for the detection of black spot and fixed point scratch defect on wafer product, and the utility model discloses can realize the multiple defect detection of wafer product in single time, greatly improves production line work efficiency, and has excellent application effect on the market.
[0033] In the actual production line based on the basis of example 1, the angle of the first angle a is set to 20 DEG in this embodiment, the setting angle of the second angle b is 45 DEG, and the setting angle of the third angle c is 75 DEG, and the emergent light of the first line light source 3, the second line light source 4 and the third line light source 5 of line sweep light source is all the preferred angle, and has better illumination effect in the detection process.
[0034] In conclusion, the utility model discloses line sweep light source cooperation line sweep camera 1 and line sweep lens 2 detection use, can improve the detection effect of wafer and detection effect, the utility model discloses the emergent light angle of multiple line light sources of constituting line sweep light source is reasonably designed, constitutes multiple illumination functions, and can realize the multiple defect detection of wafer product in single time, greatly improves production line work efficiency, and thus the utility model discloses have excellent application effect, therefore, the utility model discloses effectively overcome the various shortcomings in the prior art and have high industrial utilization value.
[0035] The above examples are only illustrative of the principles and effects of the utility model, and are not used to limit the utility model. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.
Claims
1. An optical structure suitable for multi-defect detection of wafer products, comprising a line scan camera (1) and a line scan lens (2) mounted on the acquisition end of the line scan camera (1); Its features are: Includes a line scan light source, which includes a first line light source (3), a second line light source (4), and a third line light source (5), for use as illumination (2) for wafer product inspection; The emitted light from the first line light source (3) has a first angle (a) with the horizontal plane, and the angle of the first angle (a) is 18° to 22°, which is used to detect surface scratches and pin marks on wafer products. The emitted light from the second line light source (4) has a second included angle (b) with the horizontal plane, and the angle of the second included angle (b) is 43° to 47°, which is used to detect the color difference of wafer products; The emitted light from the third line light source (5) has a third included angle (c) with the horizontal plane. The angle of the third included angle (c) is 67° to 83°, and it is used to detect black spots and fixed point scratches on wafer products.
2. The optical structure for multi-defect detection of wafer products according to claim 1, characterized in that: The angle of the first included angle (a) is 20°.
3. The optical structure for multi-defect detection of wafer products according to claim 2, characterized in that: The angle of the second included angle (b) is 45°.
4. The optical structure for multi-defect detection of wafer products according to claim 3, characterized in that: The angle of the third included angle (c) is 75°.
5. The optical structure for multi-defect detection of wafer products according to claim 1, characterized in that: The scanning width (7) of the line scan camera (1) is greater than the maximum width of the area to be inspected on the wafer product.
6. The optical structure for multi-defect detection of wafer products according to claim 5, characterized in that: The first line light source (3), the second line light source (4), and the third line light source (5) are all strip structures.
7. The optical structure for multi-defect detection of wafer products according to claim 6, characterized in that: The line scan camera (1) is provided in two sets, and the line scan light source is provided in two sets. The two line scan cameras (1) are distributed opposite to each other, and the two sets of line scan light sources are mirror-symmetrical between the two line scan cameras (1).
8. The optical structure for multi-defect detection of wafer products according to claim 6, characterized in that: It includes a detection table (6), which is placed horizontally. A rectangular frame (11) is connected to the detection table (6), and the line scan camera (1) and the line scan light source are both mounted on the frame (11).