A multi-magnification auto-focusing optical module

Abstract

The utility model relates to optical detection field discloses a kind of multi-magnification automatic focusing optical module, including detection focusing component and objective lens switching component, the detection focusing component is fixedly installed on mounting plate, objective lens switching component is movably installed on mounting plate, detection focusing component includes detection camera, focusing camera and light source, by setting detection camera, focusing camera and light source, detection camera is used to detect defect, focusing camera is used to feedback focusing information, compared with distance sensor, high precision, good stability, light source provides illumination.In the utility model, by setting objective lens switching component and other structures, drive lighter objective lens switching component to move up and down focusing, compared with drive larger and heavier detection focusing component to move up and down, the stability of hardware and detection precision are better, while improve the problem that different magnification objective lens needs manual replacement when detecting, complicated, time-consuming and laborious, affect work efficiency.

Description

Technical Field

[0001] This utility model relates to the field of optical inspection, and in particular to a multi-magnification autofocus optical module. Background Technology

[0002] Wafers are commonly used semiconductor materials. Due to the precision requirements of electronic products, it is essential to perform defect detection on individual components to promptly and effectively eliminate defective products and thus ensure the quality of electronic products.

[0003] A search revealed Chinese Patent Publication No. CN117147578A, which discloses a detection device and method capable of automatically switching lenses and autofocusing, belonging to the field of detection equipment. The detection device includes a detection unit and a transmission unit. The detection unit comprises a main inspection component and a re-inspection component and a ranging component connected to the main inspection component in the optical path. The transmission unit includes a vertical transmission component and a horizontal transmission component. The vertical transmission component is connected to the detection unit to drive the detection unit up and down based on the distance measured by the ranging component, achieving autofocus. The horizontal transmission component is connected to multiple objective lenses in the main inspection component to achieve automatic lens switching. This invention has the advantage of a compact structure and can drive the detection unit up and down based on the distance between the objective lens and the workpiece measured by the ranging component, achieving autofocus.

[0004] The above-mentioned device has the following drawbacks: during the wafer defect detection process, due to the height difference between different areas of the wafer, real-time focusing is required to achieve accurate detection; however, since the types, characteristics, and sizes of the defects to be detected are not the same, it is necessary to change the objective lens with different magnification. Manual replacement is cumbersome, time-consuming, labor-intensive, and affects work efficiency. Therefore, a multi-magnification autofocus optical module is proposed to solve the above problems. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a multi-magnification autofocus optical module, which aims to improve the problem in the prior art that different magnification objective lenses are required because the types, characteristics and sizes of the defects to be detected are not the same.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a multi-magnification autofocus optical module, comprising a detection and focusing component and an objective lens switching component. The detection and focusing component is fixedly mounted on a mounting plate, and the objective lens switching component is movably mounted on the mounting plate. The detection and focusing component includes a detection camera, a focusing camera, and a light source. By setting the detection camera, focusing camera, and light source, the detection camera is used to detect defects, and the focusing camera is used to provide feedback on focusing information. Compared with a rangefinder sensor, it has higher accuracy and better stability. The light source provides illumination. A first semi-transparent and a second semi-reflective mirror are respectively clamped at a 45° angle on the optical axis path from the detection camera to the objective lens. The reflecting surface of the first semi-transparent and a second semi-reflective mirror is adapted to the focusing camera. A reflector is clamped below the light source and is set at a 45° angle.

[0007] As a further description of the above technical solution: the objective lens switching assembly includes multiple objective lenses of different magnifications, a movable objective lens mounting plate, and a vertically movable plate. The objective lenses are respectively snapped into multiple openings for fixing and installing the objective lenses on the movable objective lens mounting plate. The movable objective lens mounting plate can move horizontally along the vertically movable plate through a horizontal moving device to realize the switching of objective lenses.

[0008] As a further description of the above technical solution: the reflecting surface of the reflector is adapted to the reflecting surface of the second semi-transparent and semi-reflective mirror.

[0009] As a further description of the above technical solution: two sliders are fixedly installed at both ends of the vertically movable plate. The two sliders are respectively movably connected to two vertical slide rails installed on the mounting plate. A connecting plate connected to the vertical moving device is also fixedly installed on the vertically movable plate. The vertical moving device drives the connecting plate, thereby moving the objective lens switching component up and down in the vertical direction to achieve automatic focusing. The detection focusing component remains stationary throughout the focusing process, resulting in higher detection accuracy. An opening for detection is provided in the middle of the vertically movable plate.

[0010] As a further description of the above technical solution: the objective lens switching assembly also includes a grating ruler assembly, which is used to control the positional accuracy of the objective lens switching movement. The grating ruler is fixedly installed on one side of the movable objective lens mounting plate, and the grating reading head is fixedly installed on the fixed frame through a fixing block.

[0011] This utility model has the following beneficial effects:

[0012] 1. In this utility model, by setting up a lens switching component and other structures, the lighter lens switching component is moved up and down to adjust the focus. Compared with moving the larger and heavier detection focusing component up and down, the hardware stability is better. Moreover, the focusing information is fed back through the focusing camera, resulting in better detection accuracy. This improves the problem of manually changing lenses of different magnifications during detection, which is cumbersome, time-consuming, labor-intensive, and affects work efficiency.

[0013] 2. In this utility model, by setting up structures such as an objective lens switching component, and by using a grating ruler component to control the positional accuracy of the objective lens switching movement, the detection accuracy is further improved, and the problem of incomplete lens switching in automatic lens switching, which affects the detection accuracy, is resolved. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall main structure of a multi-magnification autofocus optical module proposed in this utility model;

[0015] Figure 2 This is a schematic diagram of the detection and focusing component of a multi-magnification autofocus optical module proposed in this utility model;

[0016] Figure 3 This is a schematic diagram of the objective lens switching component of a multi-magnification autofocus optical module proposed in this utility model;

[0017] Figure 4 This is an exploded view of the objective lens switching component of a multi-magnification autofocus optical module proposed in this utility model.

[0018] Legend:

[0019] 1. Mounting plate; 21. Detection camera; 22. Focusing camera; 23. Light source; 24. First semi-transparent mirror; 25. Second semi-transparent mirror; 26. Reflector; 31. Objective lens; 32. Objective lens mounting plate; 321. Objective lens mounting hole; 33. Vertically movable plate; 331. Opening; 34. Slider; 35. Slide rail; 36. Horizontal moving device; 37. Connecting block; 38. Scale grating; 39. Grating reading head; 310. Connecting plate; 3101. Connecting plate opening. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Reference Figure 1 - Figure 4 This utility model provides an embodiment of a multi-magnification autofocus optical module, including a detection and focusing component and an objective lens switching component. The detection and focusing component is fixedly mounted on a mounting plate 1, and the objective lens switching component is movably mounted on the mounting plate 1. The detection and focusing component includes a detection camera 21, a focusing camera 22, and a light source 23. By setting the detection camera 21, the focusing camera 22, and the light source 23, the detection camera 21 is used to detect defects, and the focusing camera 22 is used to provide feedback on focusing information. Compared with a range sensor, it has higher accuracy and better stability. The light source 23 provides illumination. A first semi-transparent and semi-reflective mirror 24 and a second semi-transparent and semi-reflective mirror 25 are respectively clamped at a 45° angle on the optical axis path from the detection camera 21 to the objective lens 31. The reflecting surface of the first semi-transparent and semi-reflective mirror 24 is adapted to the focusing camera 22. A reflector 26 is clamped below the light source 23 and is set at a 45° angle. The reflecting surface of the reflector 26 is adapted to the reflecting surface of the second semi-transparent and semi-reflective mirror 25.

[0022] Reference Figure 2 - Figure 4 Two sliders 34 are fixedly installed at both ends of the vertical movable plate 33. The two sliders 34 are movably connected to two vertical slide rails 35 installed on the mounting plate 1. An opening 331 for detection is opened in the middle of the vertical movable plate 33. The objective lens switching assembly also includes a grating ruler assembly, which is used to control the positional accuracy of the objective lens 31 switching movement. The scale grating 38 is fixedly installed on one side of the movable objective lens mounting plate 32. The grating reading head 39 is fixedly installed on the fixed frame through a fixing block.

[0023] Reference Figure 2 - Figure 4 The objective lens switching assembly includes multiple objectives 31 with different magnifications, a movable objective lens mounting plate 32, and a vertically movable plate 33. The objectives 31 are respectively snapped into multiple objective lens mounting holes 321 on the movable objective lens mounting plate 32 for fixing the objectives 31. The movable objective lens mounting plate 32 can move horizontally along the vertically movable plate 33 via a horizontal moving device 36 to achieve objective lens switching. The horizontal moving device 36 and the movable objective lens mounting plate 32 are fixedly connected by two connecting blocks 37. An L-shaped connecting plate 310 connected to the vertical moving device is also fixedly installed on the movable plate 33. The vertical moving device drives the L-shaped connecting plate 310. By setting the vertical moving device to drive the L-shaped connecting plate 310, the objective lens switching component is moved up and down in the vertical direction to achieve automatic focusing. The detection focusing component remains stationary throughout the focusing process, resulting in higher detection accuracy. If the L-shaped connecting plate 310 obstructs the opening 331 in the middle of the vertical movable plate 33, the same connecting plate 310 opening 3101 is opened at the corresponding position.

[0024] Working principle: The movable objective lens mounting plate 32 can move horizontally along the vertical movable plate 33 via the horizontal moving device 36 to achieve the switching of the objective lens 31. At the same time, the detection camera 21 is used to detect defects, the focusing camera 22 is used to provide feedback on focusing information, and the light source 23 provides illumination. Meanwhile, the vertical moving device drives the L-shaped connecting plate 310, thereby moving the objective lens switching assembly vertically to achieve automatic focusing. The detection focusing assembly remains stationary throughout the focusing process. The grating ruler assembly is used to control the positional accuracy of the objective lens 31 switching movement.

[0025] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-magnification autofocus optical module, comprising a detection and focusing assembly and an objective lens switching assembly, characterized in that: The detection and focusing assembly is fixedly installed on the mounting plate (1), and the objective lens switching assembly is movably installed on the mounting plate (1). The detection and focusing assembly includes a detection camera (21), a focusing camera (22), and a light source (23). A first semi-transparent mirror (24) and a second semi-transparent mirror (25) are respectively attached to the optical axis path of the detection camera (21) to the objective lens (31). The reflecting surface of the first semi-transparent mirror (24) is adapted to the focusing camera (22). A reflector (26) is attached below the light source (23) and is set at an angle.

2. The multi-magnification autofocus optical module according to claim 1, characterized in that: The objective lens switching assembly includes multiple objective lenses (31) with different magnifications, a movable objective lens mounting plate (32), and a vertically movable plate (33). The objective lenses (31) are respectively snapped into multiple objective lens mounting holes (321) opened on the movable objective lens mounting plate (32) for fixing and mounting the objective lenses (31). The movable objective lens mounting plate (32) can move horizontally along the vertically movable plate (33) through a horizontal moving device (36) to realize the switching of objective lenses.

3. The multi-magnification autofocus optical module according to claim 1, characterized in that: The reflecting surface of the mirror (26) is adapted to the reflecting surface of the second semi-transparent mirror (25).

4. The multi-magnification autofocus optical module according to claim 2, characterized in that: Two sliders (34) are fixedly installed at both ends of the vertical movable plate (33). The two sliders (34) are movably connected to two vertical slide rails (35) installed on the mounting plate (1). A connecting plate (310) connected to the vertical moving device is also fixedly installed on the vertical movable plate (33). The vertical moving device drives the connecting plate (310), thereby moving the objective lens switching assembly up and down in the vertical direction. An opening (331) for detection is opened in the middle of the vertical movable plate (33).

5. A multi-magnification autofocus optical module according to claim 2, characterized in that: The objective lens switching assembly also includes a grating ruler assembly, which is used to control the positional accuracy of the objective lens switching movement. The grating ruler (38) is fixedly installed on one side of the movable objective lens mounting plate (32), and the grating reading head (39) is fixedly installed on the fixed frame by a fixing block.

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