Structured light imaging system and method suitable for semiconductor SIP (Session Initiation Protocol) system-in-package

Abstract

The invention relates to a structured light imaging system suitable for semiconductor SIP system-in-package, which comprises a central camera, and a plurality of groups of DLP projections and side cameras are symmetrically arranged on two sides of an optical axis of the central camera; the DLP projector emits parallel light beams to irradiate the surfaces of the crystal grains, and the side cameras receive reflected light rays in parallel; the device further comprises a control unit, and the control unit sequentially controls the DLP projectors and the side cameras which are symmetrically arranged in pairs to synchronously work and processes image data so as to reconstruct the three-dimensional morphology of the surface of the crystal grain. When incident light emitted by the DLP projector irradiates the surface of the crystal grain at a specific angle, specular reflection light of the incident light propagates in the symmetrical direction according to the reflection law. The side camera and the DLP projector are symmetrically arranged, so that the optical axis of the side camera is consistent with a reflection light path, and a highlight area image generated by mirror reflection is accurately captured. The layout breaks through the limitation of the traditional diffuse reflection hypothesis, so that the morphology information of the high-reflection surface can be completely acquired, and the accuracy and reliability of crystal grain three-dimensional reconstruction in SIP packaging are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of optical detection and three-dimensional imaging technology, and particularly relates to a structured light imaging system and method suitable for semiconductor SIP system-in-package. Background Technology

[0002] Multi-path structured light systems are commonly found in projection systems with four DLP (Digital Light Projectors) on the sides and a single high-resolution camera (e.g., 21 megapixels) in the center. Figure 1 As shown, the left image is a top view, and the right image is a side view. It can be seen that the DLP (Digital Perceptron) surrounds the central camera at 90-degree intervals. The central camera is typically used with a lens, usually a telecentric lens. Telecentric lenses do not exhibit the perspective effect (objects appear larger when closer, smaller when farther away), making them suitable for dimensional measurements. The purpose of the DLP's 90-degree surround is to reduce obstruction of the field of view. Figure 2 As shown, when a tall object A is present, DLP-1 will have an unilluminated shadow area on the right side, and similarly, DLP-2 will have an unilluminated shadow on the left side. If only one DLP is deployed in this multi-path structured light system, it will result in situations where shadows prevent measurement. After deploying a ring of DLPs, it was found that the areas unilluminated by DLP-1 are illuminated by DLP-2, and similarly, the shadow areas of DLP-2 are illuminated by DLP-1.

[0003] Multi-path structured light systems utilize the principle of triangulation to reconstruct the shape of objects. The principle is as follows: Figure 3 As shown, when the DLP emits incident light R1, illuminating point P of the object being measured, the diffused light R2 reflected from point P by the lens will eventually be imaged by the camera. Typically, a multi-path structured light system undergoes a calibration, or reference calibration, to establish the pose relationship between the camera, lens, and DLP. When the camera obtains an image of point P, it calculates the correspondence between R1 and R2 based on the calibrated parameters, and then uses triangulation to calculate the coordinates of point P in 3D space. By alternately projecting structured light from multiple directions using the DLP, the system can acquire more detailed information about the object's surface, effectively eliminating the shadow occlusion problem caused by a single light source, thereby improving the completeness and accuracy of 3D reconstruction.

[0004] However, from Figure 3 It can be seen that the reflected light R2 is not a specular reflection of the incident light R1 under the condition of conforming to the law of reflection, but rather diffuse reflection generated by the object's surface. However, in the SIP packaging process, there are a large number of specularly reflective dies, that is, dies with highly reflective surfaces, causing the traditional diffuse reflection assumption to fail, resulting in imaging distortion or data loss, such as... Figure 4 As shown.

[0005] When the surface of the crystal grain is specularly reflective, the incident light R1 is reflected in a specific direction after being reflected by the crystal grain surface, rather than being uniformly diffused. This causes the camera to be unable to receive an effective imaging light signal, resulting in missing images in local areas. Especially in multi-path structured light systems, even with multiple DLPs surrounding the projection, it is still difficult to overcome the directional reflection problem caused by specular reflection. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to design a structured light imaging system and method suitable for semiconductor SIP system-in-package. By symmetrically arranging DLP projectors and side cameras on both sides of the optical axis of the central camera, effective signals in the mirror reflection light path are captured, thereby solving the existing technical problems.

[0007] To address the aforementioned technical problems, this invention provides a structured light imaging system suitable for semiconductor SiP system-in-package (SiP) packaging. The system includes a central camera, on both sides of which multiple sets of DLP projectors and side cameras are symmetrically arranged. Each set of DLP projectors and side cameras is arranged symmetrically in pairs with the central camera's optical axis as the axis of symmetry, used to capture effective signals in the specular reflection light path. The DLP projectors emit parallel beams of light to illuminate the die surface, and the side cameras receive the reflected light in parallel. The system also includes a control unit, which sequentially controls the symmetrically arranged pairs of DLP projectors and side cameras to operate synchronously and processes image data to reconstruct the three-dimensional morphology of the die surface.

[0008] Furthermore, in this invention, the DLP projector includes collimating optical elements, and the side camera is equipped with a telecentric lens.

[0009] Furthermore, in this invention, the collimating optical element is a telecentric lens; or a single lens, in which the DMD inside the DLP is placed on the focal plane of the single lens, and parallel light rays are emitted after passing through the single lens.

[0010] Furthermore, in this invention, the number of pairs of symmetrically arranged DLP projectors and side cameras is 2, 3, or 4.

[0011] Furthermore, in this invention, the control unit sequentially triggers the illumination of each DLP projector and simultaneously triggers the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images.

[0012] Furthermore, in this invention, the control unit performs registration and fusion on the acquired multi-channel image data, and extracts height information from each viewpoint based on a phase demodulation algorithm.

[0013] Furthermore, in this invention, the control unit maps the three-dimensional point clouds acquired by multiple side cameras to the coordinate system of the central camera using calibration parameters.

[0014] Furthermore, in this invention, the control unit employs a weighted fusion strategy to fuse multi-view point clouds to generate a three-dimensional morphology model of the grain surface.

[0015] Furthermore, in this invention, the control unit performs planarity and coplanarity analysis on the three-dimensional topography model.

[0016] This invention also provides a structured light imaging method suitable for semiconductor SiP system-in-package, employing the aforementioned structured light imaging system suitable for semiconductor SiP system-in-package, specifically including the following steps: Step S1: Sequentially trigger the illumination of each DLP projector, and simultaneously trigger the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images.

[0017] Step S2: Based on the triangulation principle, reconstruct multiple sets of height maps HCk in the central camera coordinate system and Hk in the side camera coordinate system, where k is the trigger number, k=1,2,3,...K, and K is the number of DLP projectors deployed.

[0018] Step S3: Use a weighted fusion strategy to fuse the height map HCk in the center camera coordinate system to obtain the final height map HC-F in the center camera coordinate system.

[0019] Step S4: Based on the calibration parameters, map the height map Hk under the side camera to the coordinate system of the center camera to obtain the height map Hk-C.

[0020] Step S5: Use a weighted fusion strategy to fuse the height map Hk-C of the side camera in the coordinate system of the center camera to obtain the height map HF-C of the side camera in the coordinate system of the center camera.

[0021] Step S6: Using a weighted fusion strategy, fuse the height map HC-F under the center camera and the height map HF-C of the side camera in the center camera coordinate system to obtain the final height map HF, which is the complete height data including the die and its packaging substrate.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The structured light imaging system for semiconductor SiP system-in-package (SIP) of this invention uses a DLP projector and side cameras symmetrically arranged on both sides of the optical axis of a central camera to capture effective signals in the specular reflection light path. When the incident light emitted by the DLP projector illuminates the die surface at a specific angle, according to the law of reflection, the specularly reflected light will propagate along a symmetrical direction. The side cameras are symmetrically arranged with the DLP projector, aligning their optical axes with the reflected light path, thereby accurately capturing images of the bright areas generated by specular reflection. This arrangement overcomes the limitations of the traditional diffuse reflection assumption, enabling complete acquisition of the morphological information of highly reflective surfaces, significantly improving the accuracy and reliability of die 3D reconstruction in SIP packaging. Attached Figure Description

[0023] The specific embodiments of the present invention will be further explained below with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of a common existing multi-path structured light system.

[0025] Figure 2 A schematic diagram of the optical path principle for solving shadow problems using existing multi-angle DLP.

[0026] Figure 3 This is a schematic diagram illustrating the principle of triangulation.

[0027] Figure 4 This is a schematic diagram of the optical path that causes imaging distortion or data loss due to specular reflection from the crystal grains.

[0028] Figure 5 This is a schematic diagram of the reflected light path propagation of the structured light imaging system of the present invention, which is applicable to semiconductor SIP system-in-package, under parallel light.

[0029] Figure 6 This is a schematic diagram of a symmetrically arranged multi-path structured light in a structured light imaging system suitable for semiconductor SIP system-in-package in Example 1.

[0030] Figure 7 This is a schematic diagram of a symmetrically arranged multi-path structured light in a structured light imaging system suitable for semiconductor SIP system-in-package in Example 2.

[0031] Figure 8 This is a schematic diagram of a symmetrically arranged multi-path structured light in a structured light imaging system suitable for semiconductor SIP system-in-package in Example 3.

[0032] Figure 9 This is a flowchart of the structured light imaging method applicable to semiconductor SIP system-in-package of the present invention. Detailed Implementation Example 1

[0033] Combination Figure 6 and Figure 7 As shown, the structured light imaging system for semiconductor SIP system-in-package in this embodiment includes a central camera. Two sets of DLP projectors and side cameras are symmetrically arranged on both sides of the optical axis of the central camera, namely DLP-1 and camera-1, and DLP-2 and camera-2. The DLP projector and side camera in each set are arranged symmetrically in pairs with the optical axis of the central camera as the axis of symmetry, and are used to capture effective signals in the specular reflection light path. The DLP projector emits a parallel beam of light to illuminate the surface of the die, and the side camera receives the reflected light in parallel. The system also includes a control unit, which sequentially controls the symmetrically arranged DLP projectors and side cameras to work synchronously and processes the image data to reconstruct the three-dimensional morphology of the die surface.

[0034] In this embodiment, preferably, the DLP projector includes a collimating optical element, and the side camera is equipped with a telecentric lens. Introducing a collimating optical element at the DLP projection end effectively compresses the divergence angle of the incident light, making R1, R3, and R5 approximately parallel beams illuminating the grain surface. Correspondingly, the side camera, in conjunction with the telecentric lens, receives the reflected light rays R2, R4, and R6 in parallel, ensuring high imaging resolution and positional accuracy even with a large field of view. Since the final height data needs to coincide with the shooting angle of the central camera, the height data obtained from the side camera needs to be transformed into the coordinate system of the central camera.

[0035] In this embodiment, preferably, the collimating optical element is a telecentric lens; or it is a single lens, in which the DMD inside the DLP is placed on the focal plane of the single lens, and parallel light rays are emitted after passing through the single lens.

[0036] In this embodiment, preferably, the control unit sequentially triggers the illumination of each DLP projector and simultaneously triggers the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images.

[0037] In this embodiment, preferably, the control unit performs registration and fusion on the acquired multi-channel image data, and extracts height information from each viewpoint based on a phase demodulation algorithm.

[0038] In this embodiment, preferably, the control unit maps the three-dimensional point clouds acquired by multiple side cameras to the coordinate system of the central camera through calibration parameters.

[0039] In this embodiment, preferably, the control unit uses a weighted fusion strategy to fuse multi-view point clouds to generate a three-dimensional morphology model of the grain surface.

[0040] In this embodiment, preferably, the control unit performs planarity and coplanarity analysis on the three-dimensional topography model.

[0041] Combination Figure 9 As shown, the structured light imaging system applicable to semiconductor SIP system-in-package in this embodiment includes the following steps during use: Step 1: Trigger DLP-1 to provide illumination, and simultaneously capture images with the central camera and Camera-1. Based on the principle of triangulation, obtain the height map HC1 in the field of view of the central camera and the height map H1 in the field of view of Camera-1.

[0042] Step 2: Trigger DLP-2 for illumination, and simultaneously acquire images from the central camera and camera-2. Based on the principle of triangulation, obtain the height map HC2 under the field of view of the central camera and the height map H2 under the field of view of camera-2.

[0043] Step 3: Fuse the two height maps HC1 and HC2 from the central camera. For the same pixel, if it is valid in both HC1 and HC2, use the average of the height maps HC1 and HC2; if it is valid only in HC1, use the value of HC1; if it is valid only in HC2, use the value of HC2; if it is invalid in both, set it as an invalid point, and obtain the height map HC-F.

[0044] Step 4: By calibrating the parameters, unify the height maps H1 and H2 to the coordinate system of the central camera, and obtain the height maps H1-C and H2-C.

[0045] Step 5: Fuse the two height maps H1-C and H2-C from the side camera in the coordinate system of the center camera. For the same pixel, if it is valid in both H1-C and H2-C, then use the average value of the height maps H1-C and H2-C; if it is valid only in H1-C, then use the value of H1-C; if it is valid only in H2-C, then use the value of H2-C; if it is invalid in both, then set it as an invalid point, and obtain the height map HF-C.

[0046] Step 6: Further merge HC-F and HF-C. For the same pixel, if it is valid in both HC-F and HF-C, then use the average of the height maps of HC-F and HF-C; if it is valid only in HC-F, then use the value of HC-F; if it is valid only in HF-C, then use the value of HF-C; if it is invalid in both, then set it as an invalid point to obtain the final height map HF, which is the complete height data including the die and its packaging substrate. Example 2

[0047] Combination Figure 6 and Figure 8The structured light imaging system applicable to semiconductor SIP system-in-package in this embodiment includes a central camera. Three sets of DLP projectors and side cameras are symmetrically arranged on both sides of the optical axis of the central camera, namely DLP-1 and camera-1, DLP-2 and camera-2, and DLP-3 and camera-3. Each set of DLP projectors and side cameras are arranged symmetrically in pairs with the optical axis of the central camera as the axis of symmetry, and are used to capture effective signals in the specular reflection light path. The DLP projector emits a parallel beam of light to illuminate the surface of the die, and the side camera receives the reflected light in parallel. The system also includes a control unit, which sequentially controls the symmetrically arranged pairs of DLP projectors and side cameras to work synchronously and processes image data to reconstruct the three-dimensional morphology of the die surface.

[0048] In this embodiment, preferably, the DLP projector includes a collimating optical element, and the side camera is equipped with a telecentric lens. Introducing a collimating optical element at the DLP projection end effectively compresses the divergence angle of the incident light, making R1, R3, and R5 approximately parallel beams illuminating the grain surface. Correspondingly, the side camera, in conjunction with the telecentric lens, receives the reflected light rays R2, R4, and R6 in parallel, ensuring high imaging resolution and positional accuracy even with a large field of view. Since the final height data needs to coincide with the shooting angle of the central camera, the height data obtained from the side camera needs to be transformed into the coordinate system of the central camera.

[0049] In this embodiment, preferably, the collimating optical element is a telecentric lens; or it is a single lens, in which the DMD inside the DLP is placed on the focal plane of the single lens, and parallel light rays are emitted after passing through the single lens.

[0050] In this embodiment, preferably, the control unit sequentially triggers the illumination of each DLP projector and simultaneously triggers the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images.

[0051] In this embodiment, preferably, the control unit performs registration and fusion on the acquired multi-channel image data, and extracts height information from each viewpoint based on a phase demodulation algorithm.

[0052] In this embodiment, preferably, the control unit maps the three-dimensional point clouds acquired by multiple side cameras to the coordinate system of the central camera through calibration parameters.

[0053] In this embodiment, preferably, the control unit uses a weighted fusion strategy to fuse multi-view point clouds to generate a three-dimensional morphology model of the grain surface.

[0054] In this embodiment, preferably, the control unit performs planarity and coplanarity analysis on the three-dimensional topography model.

[0055] Combination Figure 9As shown, the structured light imaging system applicable to semiconductor SIP system-in-package in this embodiment includes the following steps during use: Step 1: Trigger DLP-1 to provide illumination, and simultaneously capture images with the central camera and Camera-1. Based on the principle of triangulation, obtain the height map HC1 in the field of view of the central camera and the height map H1 in the field of view of Camera-1.

[0056] Step 2: Trigger DLP-2 for illumination, and simultaneously acquire images from the central camera and camera-2. Based on the principle of triangulation, obtain the height map HC2 under the field of view of the central camera and the height map H2 under the field of view of camera-2.

[0057] Step 3: Trigger DLP-3 for illumination, and simultaneously acquire images from the central camera and camera-3. Based on the principle of triangulation, obtain the height map HC3 under the field of view of the central camera and the height map H3 under the field of view of camera-3.

[0058] Step 4: Merge the three height maps H1, H2, and H3 from the central camera. For the same pixel, if it is valid in all three height maps, select their average value as the height; if only two height maps are valid, select the average value from those two height maps; if only one height map is valid, select the value from that height map; if all three are invalid, mark it as an invalid point, resulting in height map HC-F.

[0059] Step 5: By calibrating the parameters, unify the height maps H1, H2, and H3 to the central camera coordinate system to obtain height maps H1-C, H2-C, and H3-C.

[0060] Step 6: Merge the three height maps H1-C, H2-C, and H3-C from the side cameras in the coordinate system of the center camera. For the same pixel, if it is valid in H1-C, H2-C, and H3-C, select their average value as the height; if only two height maps are valid, select the average value from those two height maps; if only one height map is valid, select the value from that height map; if all are invalid, set it as an invalid point, and obtain the height map HF-C.

[0061] Step 7: Further merge HC-F and HF-C. For the same pixel, if it is valid in both HC-F and HF-C, then use the average of the height maps of HC-F and HF-C; if it is valid only in HC-F, then use the value of HC-F; if it is valid only in HF-C, then use the value of HF-C; if it is invalid in both, then set it as an invalid point to obtain the final height map HF, which is the complete height data including the die and its packaging substrate. Example 3

[0062] Combination Figure 6 and Figure 9 The structured light imaging system applicable to semiconductor SIP system-in-package in this embodiment includes a central camera. Four sets of DLP projectors and side cameras are symmetrically arranged on both sides of the optical axis of the central camera, namely DLP-1 and camera-1, DLP-2 and camera-2, DLP-3 and camera-3, and DLP-4 and camera-4. Each set of DLP projectors and side cameras are arranged symmetrically in pairs with the optical axis of the central camera as the axis of symmetry, and are used to capture effective signals in the specular reflection light path. The DLP projector emits a parallel beam of light to illuminate the surface of the die, and the side camera receives the reflected light in parallel. The system also includes a control unit, which sequentially controls the symmetrically arranged pairs of DLP projectors and side cameras to work synchronously and processes image data to reconstruct the three-dimensional morphology of the die surface.

[0063] In this embodiment, preferably, the DLP projector includes a collimating optical element, and the side camera is equipped with a telecentric lens. Introducing a collimating optical element at the DLP projection end effectively compresses the divergence angle of the incident light, making R1, R3, and R5 approximately parallel beams illuminating the grain surface. Correspondingly, the side camera, in conjunction with the telecentric lens, receives the reflected light rays R2, R4, and R6 in parallel, ensuring high imaging resolution and positional accuracy even with a large field of view. Since the final height data needs to coincide with the shooting angle of the central camera, the height data obtained from the side camera needs to be transformed into the coordinate system of the central camera.

[0064] In this embodiment, preferably, the collimating optical element is a telecentric lens; or it is a single lens, in which the DMD inside the DLP is placed on the focal plane of the single lens, and parallel light rays are emitted after passing through the single lens.

[0065] In this embodiment, preferably, the control unit sequentially triggers the illumination of each DLP projector and simultaneously triggers the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images.

[0066] In this embodiment, preferably, the control unit performs registration and fusion on the acquired multi-channel image data, and extracts height information from each viewpoint based on a phase demodulation algorithm.

[0067] In this embodiment, preferably, the control unit maps the three-dimensional point clouds acquired by multiple side cameras to the coordinate system of the central camera through calibration parameters.

[0068] In this embodiment, preferably, the control unit uses a weighted fusion strategy to fuse multi-view point clouds to generate a three-dimensional morphology model of the grain surface.

[0069] In this embodiment, preferably, the control unit performs planarity and coplanarity analysis on the three-dimensional topography model.

[0070] Combination Figure 9 As shown, the structured light imaging system applicable to semiconductor SIP system-in-package in this embodiment includes the following steps during use: Step 1: Trigger DLP-1 to provide illumination, and simultaneously capture images with the central camera and Camera-1. Based on the principle of triangulation, obtain the height map HC1 in the field of view of the central camera and the height map H1 in the field of view of Camera-1.

[0071] Step 2: Trigger DLP-2 for illumination, and simultaneously acquire images from the central camera and camera-2. Based on the principle of triangulation, obtain the height map HC2 under the field of view of the central camera and the height map H2 under the field of view of camera-2.

[0072] Step 3: Trigger DLP-3 for illumination, and simultaneously acquire images from the central camera and camera-3. Based on the principle of triangulation, obtain the height map HC3 under the field of view of the central camera and the height map H3 under the field of view of camera-3.

[0073] Step 4: Trigger DLP-4 for illumination, and the center camera and camera-4 simultaneously acquire images. Based on the principle of triangulation, obtain the height map HC4 under the field of view of the center camera and the height map H4 under the field of view of camera-4.

[0074] Step 5: Merge the four height maps H1, H2, H3, and H4 from the central camera. For the same pixel, if it is valid in all three height maps, select their average value as the height; if only three height maps are valid, select the average value from those three height maps; if only two height maps are valid, select the average value from those two height maps; if only one height map is valid, select the value from that height map; if all are invalid, mark it as an invalid point, and obtain the height map HC-F.

[0075] Step 6: By calibrating the parameters, unify the height maps H1, H2, H3, and H4 to the central camera coordinate system, and obtain height maps H1-C, H2-C, H3-C, and H4-C respectively.

[0076] Step 7: Fuse the four height maps H1-C, H2-C, H3-C, and H4-C from the side cameras in the coordinate system of the center camera. For the same pixel, if it is valid in all of H1-C, H2-C, H3-C, and H4-C, select their average value as the height; if only three height maps are valid, select the average of those three; if only two height maps are valid, select the average of those two; if only one height map is valid, select that height; if all are invalid, set it as an invalid point, and obtain the height map HF-C.

[0077] Step 8: Further merge HC-F and HF-C. For the same pixel, if it is valid in both HC-F and HF-C, then use the average of the height maps of HC-F and HF-C; if it is valid only in HC-F, then use the value of HC-F; if it is valid only in HF-C, then use the value of HF-C; if it is invalid in both, then set it as an invalid point to obtain the final height map HF, which is the complete height data including the die and its packaging substrate.

[0078] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A structured light imaging system suitable for semiconductor SiP system-in-package, characterized in that: The system includes a central camera, on both sides of which multiple sets of DLP projectors and side cameras are symmetrically arranged. Each set of DLP projectors and side cameras is arranged symmetrically in pairs with the optical axis of the central camera as the axis of symmetry, and is used to capture effective signals in the specular reflection light path. The DLP projectors emit parallel beams of light to illuminate the grain surface, and the side cameras receive the reflected light in parallel. The system also includes a control unit, which sequentially controls the symmetrically arranged pairs of DLP projectors and side cameras to work synchronously and processes image data to reconstruct the three-dimensional morphology of the grain surface.

2. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 1, characterized in that: The DLP projector includes collimating optical elements, and the side camera is equipped with a telecentric lens.

3. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 2, characterized in that: The collimating optical element is a telecentric lens; or a single lens, in which the DMD inside the DLP is placed on the focal plane of the single lens, and parallel light rays are emitted after passing through the single lens.

4. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 1, characterized in that: The number of pairs of symmetrically arranged DLP projectors and side cameras is 2, 3 or 4.

5. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 1, characterized in that: The control unit sequentially triggers the illumination of each DLP projector and simultaneously triggers the central camera and the side cameras symmetrical to the currently triggered DLP projector to capture images.

6. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 5, characterized in that: The control unit performs registration and fusion of the acquired multi-channel image data, and extracts height information from each viewpoint based on the phase demodulation algorithm.

7. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 6, characterized in that: The control unit maps the 3D point clouds acquired by multiple side cameras to the coordinate system of the central camera using calibration parameters.

8. The structured light imaging system suitable for semiconductor SIP system-in-package according to claim 7, characterized in that: The control unit employs a weighted fusion strategy to fuse point clouds from multiple perspectives to generate a three-dimensional morphology model of the grain surface.

9. The structured light imaging system suitable for semiconductor SIP system-in-package as described in claim 8, characterized in that: The control unit performs planarity and coplanarity analysis on the three-dimensional topography model.

10. A structured light imaging method suitable for semiconductor SIP system-in-package, characterized in that: The structured light imaging system for semiconductor SIP system-in-package as described in any one of claims 1-9 specifically includes the following steps: Step S1: Sequentially trigger the illumination of each DLP projector, and simultaneously trigger the central camera and the side cameras symmetrical to the currently triggered DLP projector to acquire images; Step S2: Based on the triangulation principle, reconstruct multiple sets of height maps HCk in the central camera coordinate system and Hk in the side camera coordinate system, where k is the trigger number, k=1,2,3,...K, and K is the number of DLP projectors deployed. Step S3: Use a weighted fusion strategy to fuse the height map HCk in the center camera coordinate system to obtain the final height map HC-F in the center camera coordinate system; Step S4: Based on the calibration parameters, map the height map Hk under the side camera to the coordinate system of the center camera to obtain the height map Hk-C; Step S5: Use a weighted fusion strategy to fuse the height map Hk-C of the side camera in the coordinate system of the center camera to obtain the height map HF-C of the side camera in the coordinate system of the center camera. Step S6: Using a weighted fusion strategy, fuse the height map HC-F under the center camera and the height map HF-C of the side camera in the center camera coordinate system to obtain the final height map HF, which is the complete height data including the die and its packaging substrate.

Images