A three-dimensional imaging device

Abstract

This application relates to the field of semiconductor processing equipment, specifically a semiconductor inspection device, and more specifically, a three-dimensional imaging apparatus. The technical solution provided in this application includes at least one main imaging component and a coaxial light source coaxially arranged with the imaging optical path of the main imaging component. It also includes a projection component, which generates a stripe projection signal and projects it onto the surface of the object to be inspected through an optical channel opened at the coaxial light source. The signal is received by the main imaging component to obtain the three-dimensional morphological information of the object to be inspected, thereby realizing the construction of a three-dimensional model of the object. Compared with the prior art, this application combines the depth information of structured light projection with the texture information of the image, resulting in a more accurate and complete three-dimensional reconstruction, thus improving the accuracy of the reconstruction.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing equipment, specifically a semiconductor inspection device, and more specifically, a three-dimensional imaging device. Background Technology

[0002] With advancements in manufacturing technology and increasing complexity, the demand for high-precision inspection and defect detection is also growing. 3D automated optical inspection solutions can provide more detailed and accurate surface and solder joint inspections than traditional 2D automated optical inspection solutions, and therefore have wide applications in the semiconductor packaging field.

[0003] However, with advancements in industrial technology, the surfaces of industrial products are becoming increasingly complex, evolving from common planar features to curved surfaces and multi-layered structures. Furthermore, to enhance performance and shielding effectiveness, various material surfaces are frequently coated with multiple metallic layers. These changes present new challenges to inspection technologies, requiring them to adapt to the needs of different shapes, materials, and processes. Summary of the Invention

[0004] To address the aforementioned technical problems, embodiments of this application provide a three-dimensional imaging device capable of acquiring three-dimensional morphological information, performing two-dimensional measurements, and detecting surface defects with high precision and efficiency. It possesses strong adaptability and compatibility to meet various industrial testing needs.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] A three-dimensional imaging device is provided, comprising, in sequence according to an optical axis: an imaging module disposed relative to the surface of an object to be inspected, including at least one main imaging component; a coaxial light source having the same propagation path as the main imaging component; and an optical channel facing the surface of the object to be inspected further provided on the coaxial light source; and a projection component for generating stripe projection, wherein the stripe projection is projected onto the surface of the object to be inspected through the optical channel.

[0007] In another possible implementation, the coaxial light source includes: a light source plate for generating an outgoing light path; a first beam splitter located on the outgoing light path for transmitting light through the outgoing light path; a second beam splitter located on the transmitted outgoing light path for reflecting light from the outgoing light path onto the surface of the object to be tested; and an optical channel is formed between the first beam splitter and the second beam splitter.

[0008] In another possible implementation, the stripe projection is reflected sequentially onto the surface of the object to be detected by the first beam splitter and the second beam splitter.

[0009] In another possible implementation, the imaging module further includes at least two sub-imaging components, which surround the main imaging component and are symmetrically arranged with respect to the main imaging component, and the receiving surfaces of the sub-imaging components and the main imaging component are at the same distance relative to the surface of the object to be detected.

[0010] In another possible implementation, the main imaging component includes a first camera and a lens.

[0011] In another possible implementation, the sub-imaging component includes a second camera and a Sham telecentric lens.

[0012] In another possible implementation, the device further includes an annular light source between the object to be tested and the coaxial light source, with the light-emitting surface of the annular light source facing the surface of the object to be tested; the wavelength of the annular light source is any point between 400 and 1000 nanometers.

[0013] In another possible implementation, the annular light source is provided with a plurality of sub-light beads at incident angles, and the plurality of sub-light beads are evenly distributed among them.

[0014] In another possible implementation, the incident angle includes 90°, 75°, 60°, 40°, and 15°.

[0015] In another feasible embodiment, the ring light source has a multi-layer structure, with each layer having multiple sub-LEDs and each layer having a different incident angle.

[0016] In another possible implementation, the ring light source includes a first ring light, a second ring light, a third ring light, a fourth ring light, and a fifth ring light arranged in order of distance from the object to be detected.

[0017] In another possible implementation, the incident angle of the first ring light is 90°, the incident angle of the second ring light is 75°, the incident angle of the third ring light is 60°, the incident angle of the fourth ring light is 40°, and the incident angle of the fifth ring light is 15°.

[0018] In another possible implementation, the ring light source includes a first ring light, a second ring light, and a third ring light arranged from far to near relative to the object to be detected.

[0019] In another possible implementation, the incident angles of the first ring light include 90° and 75°, and the LEDs with different incident angles are evenly arranged; the incident angles of the second ring light include 60° and 40°, and the LEDs with different incident angles are evenly arranged; the incident angle of the third ring light is 15°.

[0020] The embodiments of the present invention bring the following beneficial effects:

[0021] The technical solution provided in this application provides a three-dimensional imaging device, including at least one main imaging component and a coaxial light source coaxially arranged with the imaging optical path of the main imaging component. It also includes a projection component, wherein the projection component generates a stripe projection signal and projects it onto the surface of the object to be detected through an optical channel opened at the coaxial light source. The signal is received by the main imaging component to obtain the three-dimensional morphological information of the object to be detected, thereby realizing the construction of a three-dimensional model of the object. Compared with the prior art, this application embodiment, by combining the depth information of structured light projection with the texture information of the image, can obtain a more accurate and complete three-dimensional reconstruction result, improving the reconstruction accuracy.

[0022] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0023] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] The system shown in the accompanying drawings will be further described according to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example figures represent similar mechanisms in the various views of the drawings.

[0026] Figure 1 This is a first structural schematic diagram of the three-dimensional imaging device provided in this application.

[0027] Figure 2 This is a second structural schematic diagram of the three-dimensional imaging device provided in this application.

[0028] Figure 3 This is a schematic diagram of the third structure of the three-dimensional imaging device provided in this application.

[0029] Figure 4 This is a schematic diagram of the fourth structure of the three-dimensional imaging device provided in this application.

[0030] Illustration:

[0031] 100 - Three-dimensional imaging device; 200 - Object to be detected;

[0032] 110 - Main imaging unit; 120 - Coaxial light source; 130 - Sub-imaging unit; 140 - Projection unit; 150 - Ring light source;

[0033] 111-First camera; 112-Lens; 121-Light source board; 122-First beam splitter; 123-Second beam splitter; 124-Optical channel; 131-Sham telecentric lens; 132-Second camera; 151-First ring light; 152-Second ring light; 153-Third ring light. Detailed Implementation

[0034] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0035] In the detailed description below, numerous specific details are illustrated with examples to provide a comprehensive understanding of the relevant guidance. However, it will be apparent to those skilled in the art that this application can be practiced without these details. In other instances, well-known methods, procedures, systems, components, and / or circuits have been described at a relatively high level without detail to avoid unnecessarily obscuring aspects of this application.

[0036] This application provides a three-dimensional imaging device 0, applied to the automatic optical defect detection of industrial product surfaces, particularly for the automatic optical inspection of semiconductor products. In this embodiment, semiconductor products mainly refer to IC products in the packaging process. With advancements in semiconductor product packaging technology, their surface packaging structures are becoming increasingly complex. Furthermore, to improve performance and packaging shielding effects, various materials are often coated with multiple metal plating layers. These changes pose new challenges to automatic optical inspection technology, requiring adaptation to the needs of different shapes, materials, and processes.

[0037] The current technological challenges mainly include:

[0038] Camera Selection and Performance: Traditional monochrome cameras are ineffective at detecting subtle defects such as discoloration and exposed copper. While color cameras are gradually replacing monochrome cameras in current technology, providing richer color information, the interpolation and synthesis of RGB values ​​can affect grayscale control of minor defects. Lens Accuracy: Commonly used fixed-focus lenses may exhibit near-object size variation, leading to changes in pixel accuracy during measurement and affecting the accuracy of the results. Light Source Design: Existing light source solutions lack multi-angle and multi-color combinations, resulting in insufficient compatibility for imaging complex surface defects, particularly limiting their ability to detect minor defects. 3D Measurement Technology: Current technologies typically use line lasers or binocular vision as imaging units; however, both of these approaches face challenges in adaptability and accuracy with highly reflective materials, impacting the accurate measurement capability of complex product surface morphologies.

[0039] Therefore, in response to the needs of different products with complex shapes, materials, and processes, as well as the problems existing in the prior art, this embodiment provides a three-dimensional imaging device that can achieve high-speed and high-precision quantity detection.

[0040] For details, please refer to Figure 1 This is a schematic diagram of a three-dimensional imaging device provided in this embodiment. The three-dimensional imaging device 100 includes an imaging module and a coaxial light source 120. The imaging module includes at least one main imaging component 110, and the receiving surface of the main imaging component is disposed opposite to the surface of the object to be detected 200, with its field of view covering the entire surface of the object. The coaxial light source is disposed opposite to the main imaging component to generate an incident light beam with the same propagation path as the light path of the main imaging component, thereby achieving coaxial illumination.

[0041] It is worth noting that, in this embodiment, the coaxial light source also has an optical channel 124 facing the surface of the object to be tested. This channel is used for external optical signals to pass through and propagate to the surface of the object to be tested. Specifically, the external optical signal in this embodiment is a projection signal, specifically a stripe projection signal. This signal is generated by the projection component 140, whose light-emitting surface is positioned relative to the optical channel. The stripe projection generated by the projection component is projected onto the surface of the object to be tested through the optical channel.

[0042] Therefore, the coaxial light source in this embodiment is used to generate coaxial light and to allow external optical signals to pass through. It cannot directly use existing coaxial light sources; therefore, to achieve this technical effect, a corresponding design is implemented for the coaxial light source in this embodiment. Specifically, the coaxial light source in this embodiment is sequentially arranged along the light propagation path with a light source plate 121, a first beam splitter 122, a second beam splitter 123, and a back plate. The light source plate has light beads for generating the output light path. The first beam splitter is positioned on the output light path to transmit the output light, and the second beam splitter is positioned on the transmitted output light path to reflect the output light, thus allowing the output light to be transmitted to the surface of the object to be detected, thereby forming coaxial light relative to the main imaging component and achieving the technical objective of coaxial illumination.

[0043] Furthermore, the channel formed between the first beam splitter and the second beam splitter is the optical channel 124 in this embodiment. This channel is blocked by the object facing the object to be detected and the projection component at their relative positions, thereby forming an incident light surface and an exit light surface, realizing the entry and projection of the stripe projection.

[0044] In this process, the fringe projection entering the optical channel is first reflected by a first beam splitter to a second beam splitter, and then reflected by the second beam splitter to the surface of the object to be inspected. The reflection from the object's surface generates a structured light projection, which is then received by the main imaging component. Specifically, the shape and texture of the object's surface distort and change the light pattern upon receiving the fringe projection. The deformed structured light reflected back from the object's surface is imaged by the main imaging component, forming a two-dimensional structured light pattern. After capturing the image of the deformed structured light projected object, the depth information of each point on the object's surface can be calculated by analyzing the image and the structured light projection, thereby constructing a three-dimensional model of the object.

[0045] In this embodiment, the coaxial light source, by being configured in this way, can not only be used for coaxial illumination but also be combined with a projection component to achieve structured light projection. This configuration improves the system's versatility, enabling both illumination and 3D imaging functions to be achieved on the same device. Furthermore, compared to binocular stereo vision in the prior art, this embodiment, based on a structured light scheme, transmits specific light spots or patterns, allowing humans to obtain sufficient information under different surface features. This solves the problem in prior art binocular stereo vision where depth calculation is difficult and inaccurate when the object surface lacks texture or has repetitive textures.

[0046] In order to achieve flexible adjustment of the light source directionality and optimize the compatibility and flexibility of the light source, the divergence angle of the light source board of the coaxial light source in this embodiment can be changed. For example, a light source board with a relatively large divergence angle can be configured when a wide illumination is required, while a light source board with a relatively small divergence angle can be selected in tasks that require a focused beam.

[0047] Furthermore, to improve the completeness and accuracy of 3D modeling, another 3D imaging device is also provided; please refer to [link / reference]. Figure 2 As shown. In this embodiment, in addition to the main imaging component described above, the imaging module also includes at least two sub-imaging components 130, which are arranged around the main imaging component and symmetrically about the main imaging component. The optical receiving surfaces of the sub-imaging components and the main imaging component are at the same distance from the surface of the object to be detected.

[0048] Similarly, in this embodiment, the coaxial light source and projection components are configured the same as in the previous embodiment. The difference lies in that the structured light reflected from the surface of the object to be detected is received by the main imaging component and the sub-imaging component, respectively, resulting in three structured light images. Based on the three structured light images, the image corresponding to each imaging component and the features of the structured light projection are determined. In subsequent processing, the depth information of each point on the object surface can be obtained. Then, based on the depth information of the three images, the 3D model of the object to be detected is reconstructed by fusion. The 3D model reconstructed by this method is more complete and accurate.

[0049] Furthermore, the projection components in the above embodiments include, but are not limited to, DLP optical engines, Lcos optical engines, LCD optical engines, and grating mechanical projection optical engines. The main imaging component includes a first camera 111 and a lens 112, wherein the first camera is a high frame rate and high resolution camera, and the lens is a high resolution lens. The sub-imaging components include a Schahm telecentric lens 131 and a second camera 132.

[0050] Preferably, to better distinguish discoloration and subtle changes on the surface of the object to be detected, a full-spectrum light source is also provided in the 3D imaging device. For more information on this 3D imaging device, please refer to [link to relevant documentation]. Figure 3 As shown, a ring light source 150 is positioned between the object to be detected and the coaxial light source. The light-emitting surface of the ring light source faces the surface of the object to be detected. In this embodiment, the ring light source integrates full-spectrum LEDs, which can be switched within a wavelength range of 400-1000 nanometers via a controller. The ring light source calibrates the brightness of the three RGB colors and synthesizes a color image from the three RGB images to improve the image's color information and detail capture capabilities. Compared to a black and white image, it can better distinguish changes on the surface of the object to be detected.

[0051] The ring light source contains multiple LEDs with different incident angles, and these LEDs are evenly distributed among each other.

[0052] Specifically, in this embodiment, the incident angles of the LED beads include 90°, 75°, 60°, 40° and 15°. By setting LED beads with different incident angles, different imaging results can be obtained, and photometric stereo processing can be performed based on the different imaging results to obtain the features of fine surface defects.

[0053] Furthermore, to ensure the uniform distribution of multiple LEDs and the guarantee of lighting effect, this embodiment uses a multi-layer structure for the ring light source, with LEDs at different incident angles arranged in different layers. The multi-layer ring light source includes a first ring light, a second ring light, a third ring light, a fourth ring light, and a fifth ring light, arranged from farthest to near the object to be detected, with the illumination range of the multiple ring lights gradually increasing from farthest to near. The incident angle of the first ring light is 90°, the second ring light is 75°, the third ring light is 60°, the fourth ring light is 40°, and the fifth ring light is 15°.

[0054] Preferably, while the aforementioned multi-layer ambient light increases the distribution density of LEDs and enhances the lighting effect, it also requires a relatively large space for the ring light structure. To ensure the simplicity of the placement space for the multi-layer ring light source, please refer to [the relevant documentation / reference needed]. Figure 4 In this embodiment, the ring light source is preferably provided with a first ring light 151, a second ring light 152 and a third ring light 153 from far to near.

[0055] The first ring light has incident angles of 90° and 75°, meaning it contains multiple LEDs with 90° incident angles and multiple LEDs with 75° incident angles, with the LEDs at both incident angles evenly distributed. The second ring light has incident angles of 60° and 40°, similar to the first ring light, but it contains multiple LEDs with incident angles of 60° and 40°, also evenly distributed. The third ring light has an incident angle of 15°, and it is described that the third ring light contains only LEDs with an incident angle of 15°.

[0056] In summary, this application provides a three-dimensional imaging device that preferentially combines trinocular stereo vision with structured beam projection. This allows for complete and accurate three-dimensional reconstruction results, improving reconstruction precision. Furthermore, trinocular vision enables error correction and reconstruction verification by comparing the imaging results from multiple imaging components, enhancing system stability and robustness. Moreover, for objects where the detected object may have occlusions or invisible surfaces, the front-projection trinocular stereo vision scheme allows for the acquisition of occluded or invisible areas using cameras at different angles, resulting in a more complete three-dimensional reconstruction. Additionally, by adding a combined ring light source, this device can synthesize a true-color image from three black-and-white images illuminated by RGB lighting. Compared to conventional color cameras, the true-color image exhibits higher realism and sharpness, and the grayscale values ​​of the image pixels are true values. The ring light source has a full spectrum, providing a high color reproduction index to accurately reproduce the true colors of objects, making it suitable for color difference identification and defect detection.

[0057] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional imaging device, characterized in that, The following are arranged sequentially according to the optical axis: An imaging module is disposed relative to the surface of the object to be detected, including at least one main imaging component; The coaxial light source has the same propagation path as the main imaging component; and an optical channel facing the surface of the object to be detected is also provided on the coaxial light source. A projection component is used to generate a stripe projection, and the stripe projection is projected onto the surface of the object to be inspected through the optical channel.

2. The three-dimensional imaging device according to claim 1, characterized in that, The coaxial light source includes: The light source board is used to generate the light output path; The first beam splitter is located on the light output path and is used to transmit light through the light output path; The second beam splitter is located on the path of the emitted light after transmission and is used to reflect the emitted light onto the surface of the object to be tested. The optical channel is formed between the first beam splitter and the second beam splitter.

3. The three-dimensional imaging device according to claim 2, characterized in that, The stripe projection is reflected sequentially by the first beam splitter and the second beam splitter onto the surface of the object to be tested.

4. The three-dimensional imaging device according to claim 1, characterized in that, The imaging module further includes at least two sub-imaging components, which surround the main imaging component and are symmetrically arranged with respect to the main imaging component. The receiving surfaces of the sub-imaging components and the main imaging component are at the same distance relative to the surface of the object to be detected.

5. The three-dimensional imaging device according to claim 1 or 4, characterized in that, The main imaging component includes a first camera and a lens.

6. The three-dimensional imaging device according to claim 4, characterized in that, The sub-imaging component includes a second camera and a Sham telecentric lens.

7. The three-dimensional imaging device according to claim 1, characterized in that, The device also includes a ring light source between the object to be tested and the coaxial light source, with the light-emitting surface of the ring light source facing the surface of the object to be tested; the wavelength of the ring light source is adjustable and is between 400 and 1000 nanometers.

8. The three-dimensional imaging device according to claim 7, characterized in that, The ring light source is provided with multiple sub-light beads with incident angles, and the multiple sub-light beads are evenly distributed among them.

9. The three-dimensional imaging device according to claim 8, characterized in that, The incident angles include 90°, 75°, 60°, 40°, and 15°.

10. The three-dimensional imaging device according to claim 9, characterized in that, The ring light source has a multi-layer structure, with multiple sub-LEDs in each layer and each layer having a different incident angle.

11. The three-dimensional imaging device according to claim 10, characterized in that, The ring light source includes a first ring light, a second ring light, a third ring light, a fourth ring light, and a fifth ring light, arranged from far to near relative to the object to be detected.

12. The three-dimensional imaging device according to claim 11, characterized in that, The incident angle of the first ring light is 90°, the incident angle of the second ring light is 75°, the incident angle of the third ring light is 60°, the incident angle of the fourth ring light is 40°, and the incident angle of the fifth ring light is 15°.

13. The three-dimensional imaging device according to claim 10, characterized in that, The ring light source includes a first ring light, a second ring light, and a third ring light arranged from far to near relative to the object to be detected.

14. The three-dimensional imaging device according to claim 13, characterized in that, The first ring light has incident angles of 90° and 75°, and the LEDs with different incident angles are evenly arranged; the second ring light has incident angles of 60° and 40°, and the LEDs with different incident angles are evenly arranged; the third ring light has an incident angle of 15°.

Images