WO2021071420A1

WO2021071420A1 - System and method for multi-view inspection of a bonding structure

Info

Publication number: WO2021071420A1
Application number: PCT/SG2019/050501
Authority: WO
Inventors: Kum Pang Chung; Yoon Foo Cheow; Xiao Ke SHI; Wei Huan LUO; Han Kyin PHYO; Yi Qing Estelle TAY
Original assignee: Component Technology Pte Ltd
Priority date: 2019-10-07
Filing date: 2019-10-07
Publication date: 2021-04-15

Abstract

Embodiments of the invention provide system and method for multi-view inspection of a bonding structure. The system comprises a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub-module and a placement area for the bonding structure, and at least part of the first and/or the second sub-module are movable between a first configuration and a second configuration, when in the first configuration, the first reflection component is arranged to provide light from the bonding structure in a first direction to the camera to conduct a first view inspection; and when in the second configuration, the second reflection component is arranged to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection.

Description

SYSTEM AND METHOD FOR MULTI-VIEW INSPECTION OF

A BONDING STRUCTURE

Field of Invention

[0001] The invention relates to inspection system and method for a bonding structure of a substrate, and more specifically to system and method for multi-view inspection of a bonding structure.

Background

[0002] Wire bonding is an interconnect technology widely used in semiconductor device fabrication. In a wire bonding process, a die pad is electrically connected to a package lead in a lead frame by using a wire. The wire bonded die and lead frame thereafter may be further packaged in plastic or ceramic to form a semiconductor device, e.g. an integrated circuit (1C) device.

[0003] Inspection of the bonding structure from different views is a very important way to determine whether the quality of the bonding structure, e.g. the die bond and wire bond, satisfies the manufacturing requirements. In the past, the inspection process may be conducted by a human operator using a microscope. However, this manual method may be time consuming and inaccurate.

[0004] More recently, certain automatic inspection systems have been proposed. However, most of the existing automatic inspection systems have complicated structure and therefore it may not be easy to set up these systems. Further, the existing systems may be very costly since a large number of different optical components are required to inspect different views of a bonding structure. For example, in one existing automatic inspection system, at least two cameras are needed to conduct inspection of the bonding structure, and the system also includes a structure specially designed for providing uniform illumination, various light sources, and different sets of light reflection arrangements.

Summary of Invention

[0005] Embodiments of the invention provide a simple and cost-effective system and method for multi-view inspection of a bonding structure.

[0006] According to one aspect of the invention, a system for multi-view inspection of a bonding structure is provided. The system comprises: a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub-module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or at least part of the second sub-module is arranged to be movable between a first configuration and a second configuration; when in the first configuration, the first reflection component is arranged to provide light from the bonding structure in a first direction to the camera to conduct a first view inspection of the bonding structure; and when in the second configuration, the second reflection component is arranged to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection of the bonding structure.

[0007] According to a second aspect of the invention, a method for multi view inspection of a bonding structure is provided. The method comprises: providing a system which comprises a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub-module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or the second sub-module is arranged to be movable between a first configuration and a second configuration; when in the first configuration, the first reflection component is configured to provide light from the bonding structure in a first direction to the camera to conduct a first view inspection of the bonding structure; and when in the second configuration, the second reflection component is configured to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection of the bonding structure; and conducting the first view inspection of the bonding structure when the system is in the first configuration and conducting the second view inspection when the system is in the second configuration.

Brief Description of the Drawings

[0008] The invention will be described in detail with reference to the accompanying drawings, in which:

[0009] Figure 1 (a) is a front sectional view of a first system in a first configuration according to a first embodiment of the invention;

[0010] Figure 1 (b) is a front sectional view of the first system in a first arrangement of a second configuration when the second sub-module is moved to a right position according to a first example of the first embodiment;

[0011] Figure 1 (c) is a front sectional view of the first system in second arrangement of the second configuration when the second sub-module is moved to a left position according to the first example;

[0012] Figure 1 (d) is a front sectional view of the first system in a first arrangement of a second configuration when the first sub-module is moved to a left position according to a second example of the first embodiment; [0013] Figure 1 (e) is a front sectional view of the system in a second arrangement of the second configuration when the first sub-module is moved to a right position according to the second example;

[0014] Figure 2(a) is a front sectional view of a second system in a first configuration according to a second embodiment of the invention;

[0015] Figure 2(b) is a front sectional view of the second system in a first arrangement of a second configuration when the second sub-module is moved to a right position according to a first example of the second embodiment;

[0016] Figure 2(c) is a front sectional view of the second system in a second arrangement of the second configuration when the second sub-module is moved to a left position according to the first example;

[0017] Figure 2(d) is a front sectional view of the second system in a first arrangement of a second configuration when the first sub-module is moved to a left position according to a second example of the second embodiment ; [0018] Figure 2(e) is a front sectional view of the second system in a second arrangement of the second configuration when the first sub-module is moved to a right position according to the second example;

[0019] Figure 3(a) is a perspective view of the second reflection component according to the first embodiment of the invention; [0020] Figure 3(b) is a top view of the second sub-module showing the second reflection component disposed in the dome light according to the first embodiment of the invention;

[0021] Figure 4 is a front sectional view of a third system for multi-view inspection of a bonding structure according to a third embodiment of the invention;

[0022] Figure 5 is a flow chart illustrating a method for multi-view inspection of a bonding structure according to one embodiment of the invention.

Detailed Description of Embodiments of the Invention [0023] In the following description, numerous specific details are set forth in order to provide a thorough understanding of various illustrative embodiments of the invention. It will be understood, however, to one skilled in the art, that embodiments of the invention may be practiced without some or all of these specific details. It is understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention.

[0024] Embodiments described in the context of one of the methods or devices are analogously valid for the other methods or devices. Similarly, embodiments described in the context of a method are analogously valid for a device, and vice versa.

[0025] Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0026] As used herein, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements.

[0027] As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0028] As used herein, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0029] As used herein, the term “configured to” is interchangeable with “operative” or “adapted to”.

[0030] Embodiments of the invention provide a system for multi-view inspection of a bonding structure. The system comprises: a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub-module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or at least part of the second sub-module is arranged to be movable between a first configuration and a second configuration; when in the first configuration, the first reflection component is arranged to provide light reflected from the bonding structure in a first direction to the camera to conduct a first view inspection of the bonding structure; and when in the second configuration, the second reflection component is arranged to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection of the bonding structure.

[0031] It should be noted that the at least part of the first/second sub- module may include the whole or only some components of the first/second sub- module; the light from the bonding structure may include light reflected from/off the bonding structure; the second configuration may include a plurality of different arrangements of the system; and each arrangement provides a second direction different from other arrangements of the second configuration.

[0032] In some embodiments of the invention, the at least part of the first sub-module and/or the at least part of the second sub-module may be arranged to be movable along a third direction in a plane perpendicular to the first direction to dispose the system in the second configuration.

[0033] In some embodiments of the invention, the third direction may include a first possible direction and a second possible direction in the plane perpendicular to the first direction. Accordingly, the at least part of the first sub- module and/or the at least part of the second sub-module may be arranged to be movable along the first possible direction to dispose the system in a first arrangement of the second configuration, and movable along the second possible direction to dispose the system in a second arrangement of the second configuration.

[0034] In one example, the first direction is the positive z-axis direction, and the third direction includes a positive x-axis direction, a negative x-axis direction, a positive y-axis direction, and a negative y-axis direction in the plane perpendicular to the positive z-axis direction. Accordingly, the at least part of the first sub-module or the at least part of the second sub-module may be arranged to be movable along each of the positive x-axis direction, the negative x-axis direction, the positive y-axis direction, and the negative y-axis direction to dispose the system in four different arrangements of the second configuration respectively. In this example, the second configuration includes four different arrangements and each arrangement of the second configuration provides a different second direction from the bonding structure to the second reflection component.

[0035] In some embodiments of the invention, the camera may be further configured to capture a first view image of the bonding structure when conducting the first view inspection of the bonding structure and capture at least one second view image of the bonding structure when conducting the second view inspection of the bonding structure. For example, when the second configuration includes a plurality of arrangements, e.g. four different arrangements, the camera may be configured to capture a different view image of the bonding structure in each arrangement. [0036] In some embodiments of the invention, the camera may be arranged such that its optical axis is substantially perpendicular to the first direction. In these embodiments, the first reflection component is disposed between the first light source and the second reflection component in the first direction; when in the first configuration, the first reflection component is arranged to allow the light from the first light source to transmit to the placement area, and provide light from the bonding structure in the first direction to the camera to conduct the first view inspection; when in the second configuration, the first reflection component is arranged to reflect the light from the second reflection component in the first direction to the camera to conduct the second view inspection.

[0037] In some embodiments of the invention, the camera may be arranged such that its optical axis is directed to the placement area, or substantially parallel to the first direction. In these embodiments, the first reflection component is disposed between the camera and the second reflection component in the first direction, when in the first configuration, the first reflection component is arranged to reflect light from the first light source to the placement area, and allow the light from the bonding structure in the first direction to transmit to the camera; when in the second configuration, the first reflection component is arranged to allow the light reflected from the second reflection module in the first direction to transmit to the camera.

[0038] In some embodiments of the invention, the first light source may include a coaxial light. [0039] In some embodiments of the invention, the first reflection module may include a beam splitter.

[0040] In some embodiments of the invention, the second sub-module may further include a second light source which is disposed between the second reflection component and the placement area, wherein the second light source may include a ring light or a low-angle light. The second light source may be provided to further highlight wires as well as scratches and foreign particles, such as dust and contaminants, on the bonding structure.

[0041] In some embodiments of the invention, the second sub-module may further include a third light source which is disposed on the second light source to provide uniform illumination and improve contrast of features of the bonding structure, wherein the third light source may include a dome light.

[0042] In some embodiments of the invention, the second reflection component may be disposed on the third light source, e.g. on a bottom internal surface of the third light source.

[0043] In some embodiments of the invention, to inspect different views of the bonding structure, the second reflection component may include at least one mirror, wherein each mirror is disposed at a predetermined angle with respect to an axis along the first direction. [0044] In one embodiment of the invention, the second reflection component may include four mirrors and each mirror may be disposed along an edge of a rectangle/square and at an angle of about 22.5 degrees with respect to an axis along the first direction. Each mirror of the second reflection component may be used for inspecting a different view of the bonding structure.

[0045] In some embodiments of the invention, the system may further include a first movable platform on which at least part of the first sub-module is disposed, wherein the first movable platform is movable to dispose the system in the first configuration or the second configuration. For example, the first movable platform may be movable between a first position where the system is in the first configuration and at least one second position where the system is in the second configuration. The at least one second position may include four different positions. In one example, the first movable platform may include a linear XY table.

[0046] In some embodiments of the invention, the system may further include a second movable platform on which at least part of the second sub- module is disposed, wherein the second movable platform is movable to dispose the system in the first configuration or the second configuration. For example, the second movable platform may be movable between a third position where the system is in the first configuration and at least one fourth position where the system is in the second configuration. The at least one fourth position may include four different positions. In one example, the second movable platform may include a linear XY table.

[0047] It should be noted that in some embodiments, maybe at least part of the first sub-module or at least part of the second sub-module is arranged to be movable such that the system can be moved to the second configuration; while in other embodiments, maybe both at least part of the first sub-module and at least part of the second sub-module are movable such that the system can be moved to the second configuration. At least part of the first/second sub-system means that the whole sub-system or only some components of the sub-system. For example, in some embodiments of the invention, the second light source, the third light source and the second reflection component of the second sub-module may be mounted on the second movable platform and moved together to dispose the system in the second configuration.

[0048] In some embodiments of the invention, the system may further include a complementary camera and a beam splitter, wherein the beam splitter is disposed between the first reflection component and the camera, and arranged to split light from the first reflection component into a first beam to be transmitted to the camera and a second beam to be transmitted to the complementary camera; wherein the complementary camera is arranged to receive the second beam and conduct a first view inspection of the bonding structure when the system is in the first configuration, and conduct a second view inspection when the system is in the second configuration.

[0049] In some embodiments of the invention, the complementary camera may be further configured to capture a first view image of the bonding structure structure with a predetermined resolution, e.g. a predetermined resolution higher than that of the camera, when conducting the first view inspection; and capture at least one second view image of the bonding structure with a predetermined resolution when conducting the second view inspection. [0050] In some embodiments of the invention, the system may further include a mirror configured to reflect the second beam from the beam splitter to the complementary camera.

[0051] In some embodiments of the invention, the first view image of the bonding structure may include a top view image of the bonding structure, and the at least one second view image of the bonding structure may include a right side view image, a left side view image, a front view image, and/or a rear view image of the bonding structure.

[0052] In some embodiments of the invention, to obtain information about the bonding structure based on the acquired first view image and the at least one second view image of the bonding structure, the system may further include a processing device, e.g. a computer.

[0053] In some embodiments, the processing device may be configured to conduct at least one of the following to determine information about the bonding structure: identify a sagging wire and/or a shorted wire based on the at least one second view image of the bonding structure; calculate solder ball height, wire loop height and/or fillet height based on the at least one second view image of the bonding structure; and calculate bond line thickness and/or die tilt based on information obtained from both the first view image and the at least one second view image of the bonding structure.

[0054] Figures 1 (a) to 1 (e) are front sectional views of a first system 100 for multi-view inspection of a bonding structure 10 according to a first embodiment of the invention. The bonding structure 10 includes a wire bond 101. In this embodiment, the first system 100 includes a first sub-module 110 and a second sub-module 120. The first sub-module 110 includes a camera 111 , a first light source 112 and a first reflection component 113. The second sub- module 120 includes a second reflection component 121 , a second light source 122 and a third light source 123.

[0055] Referring to Figures 1 (a) to 1 (e), in this embodiment, the camera 111 is arranged such that its optical axis is substantially perpendicular to the first direction, i.e. the positive z-axis direction shown in Figure 1 (a). The first reflection component 113 is disposed between the first light source 112 and the second reflection component 121 and along the first direction. The second sub- module 120 is disposed between the first sub-module 110 and a placement area 130 in which the bonding structure 10 is positioned. The first sub-module 110 and/or the second sub-module 120 is arranged to be movable between a first configuration and a second configuration.

[0056] Figure 1 (a) is a front sectional view of the first system 100 in the first configuration according to the first embodiment of the invention. In the first configuration, both the first sub-module 110 and the second sub-module 120 are arranged in a first/home position. The camera 111 is configured to conduct a first view inspection of the bonding structure 10, e.g. the top view inspection of the bonding structure 10. As shown in Figure 1 (a), the first reflection component 113 is arranged to allow transmission of light from the first light source 112 to pass through the first reflection component 113 to reach the placement area 130, and provide, e.g. reflect, light from the bonding structure 10 in the first direction to the camera 111 to conduct the first view inspection of the bonding structure 10. The camera 111 may be configured to capture a first view image of the bonding structure 10, e.g. a top view image of the bonding structure 10, when the first system 100 is in the first configuration.

[0057] In this embodiment, the second reflection component 121 includes four mirrors 121a-121d as shown in Figures 3(a) and 3(b). Each of the four mirrors 121 a-121 d is disposed along an edge of a rectangle/square and at an angle of about 22.5 degrees with respect to an axis along the first direction. It should be noted that the number, size and angle of the mirrors included in the second reflection component 121 may vary in different embodiments of the invention according to the actual needs and requirements.

[0058] Figures 1 (b) and 1 (c) are front sectional views of the first system 100 in a first arrangement and a second arrangement of the second configuration respectively when the second sub-module 120 is moved to arrange the first system 100 in the second configuration according to a first example of the first embodiment of the invention. [0059] As shown in Figure 1 (b), the second sub-module 120 is moved to the right position along the positive y-axis direction. In the first arrangement of the second configuration, the mirror 121a of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a first instance of the second direction, i.e. the second direction 11a, to the camera 111 to conduct a second view inspection of the bonding structure 10. Specifically, the mirror 121a is arranged to reflect the light from the bonding structure 10 in the second direction 11 a to the first reflection component 113 which in turn reflects the light from the mirror 121a to the camera 111. In this arrangement, the camera 111 may be configured to capture a right side view image of the bonding structure 10.

[0060] As shown in Figure 1 (c), the second sub-module 120 is moved to the left position along the negative y-axis direction. In the second arrangement of the second configuration, the mirror 121 b of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the wire bond 101 of the bonding structure 10 in a second instance of the second direction, i.e. the second direction 11 b, to the camera 111 to conduct a second view inspection of the bonding structure 10. Specifically, the mirror 121 b is arranged to reflect light from the wire bond 101 in the second direction 11 b to the first reflection component 113 which in turn reflects the light from the mirror 121 b to the camera 111. In this arrangement, the camera 111 may be configured to capture a left side view image of the bonding structure 10. [0061] Although it is not shown in Figures, it should be understood that the second configuration in the first example of the first embodiment may further include a third arrangement and a fourth arrangement of the second configuration. In the third arrangement, the second sub-module 120 may be moved to a front position along the positive x-axis direction such that the mirror 121c of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a third instance of the second direction to the camera 111 to conduct a second view inspection of the bonding structure 10, e.g. capture a front view image of the bonding structure 10. In the fourth arrangement, the second sub-module 120 may be moved to a rear position along the negative x-axis direction such that the mirror 121 d of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a fourth instance of the second direction, to the camera 111 to conduct a second view inspection of the bonding structure 10, e.g. capture a rear view image of the bonding structure 10.

[0062] In view of the above, in the first example of the first embodiment, when the second sub-module 120 is moved to arrange the system 100 in the second configuration, the second configuration may include four different arrangements of the system 100 although only two of the arrangements are shown in Figure 1 (b) and (c) respectively. Each arrangement corresponds to a different instance of the second direction, e.g. the first arrangement in Figure 1 (b) corresponds to the first instance of the second direction, i.e. the second direction 11a; and the second arrangement in Figure 1 (c) corresponds to the second instance of the second direction, i.e. the section direction 11 b. In each of the four arrangements, the system 100 may be used to conduct a different view inspection of the bonding structure 10, e.g. capture a different view image of the bonding structure 10.

[0063] The movement of the second sub-module 120 may be realized by a movable platform (not shown in Figures) on which the second sub-module 120 is disposed. In one example, the moveable platform may include a linear XY table. [0064] It should be noted that in some embodiments of the invention, the second sub-module 120 may be moved as a whole to the right or the left position, or only part of the second sub-module 120, e.g. the second reflection component 121 and the third light source 123, is moved to the right or the left position. [0065] Figure 1 (d) and Figure 1 (e) are front sectional views of the first system 100 in a first arrangement and a second arrangement of the second configuration respectively when the first sub-module 110 is moved to arrange the system 100 in the second configuration according to a second example of the first embodiment of the invention. [0066] As shown in Figure 1 (d), the first sub-module 110 is moved to the left position along the negative y-axis direction. In this second configuration, the mirror 121 a of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a first instance of the second direction, i.e. the second direction 12a, to the camera 111 to conduct a second view inspection of the bonding structure 10. In this second configuration, the camera 111 may be configured to capture a right side view image of the bonding structure 10.

[0067] As shown in Figure 1 (e), the first sub-module 110 is moved to a right position along the positive y-axis direction. In this second configuration, the mirror 121 b of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the wire bond 101 of the bonding structure 10 in a second instance of the second direction, i.e. the second direction 12b, to the camera 111 to conduct a second view inspection of the bonding structure 10. In this second configuration, the camera 111 may be configured to capture a left side view image of the bonding structure 10.

[0068] Although it is not shown in Figures, it should be understood that the second configuration in the second example may further include a third arrangement and a fourth arrangement of the system 100. In the third arrangement, the first sub-module 110 may be moved to a front position along the positive x-axis direction such that the mirror 121c of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a third instance of the second direction, to the camera 111 to conduct a second view inspection of the bonding structure 10, e.g. capture a front view image of the bonding structure 10. In the fourth arrangement of the second configuration, the first sub-module 110 may be moved to a rear position along the negative x-axis direction such that the mirror 121 d of the second reflection component 121 is arranged to provide, through the first reflection component 113, light from the bonding structure 10 in a fourth instance of the second direction, to the camera 111 to conduct a second view inspection of the bonding structure 10, e.g. capture a rear view image of the bonding structure 10.

[0069] In view of the above, in the second example of the first embodiment, when the first sub-module 110 is moved to arrange the system 100 in the second configuration, the second configuration may also include four different arrangements of the system 100 although only two of the arrangements are shown in Figure 1 (d) and (e) respectively. Each arrangement corresponds to a different instance of the second direction, e.g. the first arrangement in Figure 1 (d) corresponds to the first instance of the second direction, i.e. the second direction 12a and the arrangement in Figure 1 (e) corresponds to the second instance of the second direction, i.e. the second direction 12b. In each of the four arrangements, the system 100 may be used to conduct a different view inspection of the bonding structure 10, e.g. capture a different view image of the bonding structure 10.

[0070] It should be noted that in some embodiments of the invention, the first sub-module 110 may be moved as a whole to the right or the left position, or only part of the first sub-module 110, e.g. only the first light source 112 and the first reflection component 113, is moved to the right or the left position. [0071] The movement of the first sub-module 110 may be realized by a movable platform on which the first sub-module 110 is disposed. In one example, the moveable platform may include a linear XY table.

[0072] In the first embodiment, either the first sub-module 110 or the second sub-module 120 is moved to arrange the first system 100 in the second configuration. However, it should be understood that in some embodiments of the invention, the first system 100 may be arranged in the second configuration by moving both the first sub-module 110 and the second sub-module 120. Further, in some embodiments, only part of the first sub-module 110 and/or part of the second sub-module 120 may be moved to arrange the first system 100 in the second configuration. The second configuration may include different arrangements of the first system 100.

[0073] Figures 2(a) to 2(e) are front sectional views of a second system 200 for multi-view inspection of a bonding structure 20 according to a second embodiment of the invention. In the second embodiment, different from the first embodiment in Figures 1 (a) to 1 (e), the camera 211 is arranged such that its optical axis is substantially parallel to the first direction, or directed to the placement area 230. The first reflection component 213 is disposed between the camera 211 and the second reflection component 221 , and along the first direction, i.e. the positive z-axis direction. The second sub-module 220 is disposed between the first sub-module 210 and the placement area 230. The first sub-module 210 and/or the second sub-module 220 is arranged to be movable between a first configuration and a second configuration. Figure 2(a) is a front sectional view of the second system 200 in the first configuration according to the second embodiment. In the first configuration, both the first sub-module 210 and the second sub-module 220 are arranged in a first/home position. The camera 211 is configured to conduct a first view inspection of the bonding structure 20, e.g. capture a top view image of the bonding structure 20. As shown in Figure 2(a), the first reflection component 213 is arranged to reflect light from the first light source 212 to the placement area 230, and allow the light from the bonding structure 20 in the first direction to transmit to the camera 211 . The camera 211 may be configured to capture a first view image of the bonding structure 20 when the second system 200 is in the first configuration. The first view image of the bonding structure 20 may be the top view image of the bonding structure 20.

[0074] The second reflection component 221 which includes four mirrors 221a-221d may be same as the second reflection component 121 in the first embodiment.

[0075] Figure 2(b) and Figure 2(c) are front sectional views of the second system 200 in a first arrangement and a second arrangement of the second configuration respectively when the second sub-module 220 is moved to arrange the system 200 in the second configuration according to a first example of the second embodiment of the invention.

[0076] As shown in Figure 2(b), the second sub-module 220 is moved to the right position along the positive y-axis direction as shown in Figure 2(b). In the first arrangement of the second configuration, the mirror 221a of the second reflection component 221 is arranged to reflect light from the bonding structure 20 in a first instance of the second direction, i.e. the second direction 21 a, to the first reflection component 213, and the first reflection component 213 is arranged to allow the light reflected from the mirror 221 a to transmit to the camera 211. In this arrangement, the camera 211 may be configured to capture a right side view image of the bonding structure 20.

[0077] Similarly, as shown in Figure 2(c), the second sub-module 220 is moved to the left position along the negative y-axis direction as shown in Figure 2(c). In the second arrangement of the second configuration, the mirror 221 b is arranged to reflect light from the wire bond 201 of the bonding structure 20 in a second instance of the second direction, i.e. the second direction 21 b, to the first reflection component 213, and the first reflection component 213 is arranged to allow the light reflected from the mirror 221a to transmit to the camera 211. In this arrangement, the camera 211 may be configured to capture a left side view image of the bonding structure 20.

[0078] Although it is not shown in Figures, it should be understood that the second configuration in the first example of the second embodiment may further include a third arrangement and a fourth arrangement of the second configuration. In the third arrangement, the second sub-module 220 may be moved to a front position along the positive x-axis direction such that the mirror 221c of the second reflection component 221 is arranged accordingly to reflect light from the bonding structure 20 in a third instance of the second direction to the first reflection component 213 such that a front view inspection of the bonding structure 20 is conducted, e.g. a front view image of the bonding structure 20 is captured. In the fourth arrangement, the second sub-module 220 may be moved to a rear position along the negative x-axis direction such that the mirror 221 d of the second reflection component 221 is arranged to reflect light from the bonding structure 20 in a fourth instance of the second direction to the first reflection component 213 such that a rear view inspection of the bonding structure 20 is conducted, e.g. a rear view image of the bonding structure 20 is captured. [0079] Similar to the first embodiment, the second system 200 may also be moved to the second configuration by moving the first sub-module 210 as shown in Figure 2(d) and 2(e). Figure 2(b) and Figure 2(c) are front sectional views of the second system 200 in a first arrangement and a second arrangement of the second configuration respectively when the first sub-module 210 is moved to arrange the system 200 in the second configuration according to a second example of the second embodiment of the invention.

[0080] As shown in Figure 2(d), the first sub-module 210 is moved to the left position along the negative y-axis direction. In the first arrangement of the second configuration, the mirror 221a of the second reflection component 221 is arranged to reflect light from the bonding structure 20 in a first instance of the second direction, i.e. the second direction 22a, to the first reflection component 213, and the first reflection component 213 is arranged to allow the light reflected from the mirror 221a to transmit to the camera 211. In this arrangement, the camera 211 may be configured to capture a right side view image of the bonding structure 20.

[0081] As shown in Figure 2(e), the first sub-module 210 is moved to a right position along the positive y-axis direction. In the second configuration, the mirror 221 b is arranged to to reflect light from the wire bond 201 of the bonding structure 20 in a second instance of the second direction, i.e. the second direction 22b, to the first reflection component 213, and the first reflection component 213 is arranged to allow the light reflected from the mirror 221 a to transmit to the camera 211. In this arrangement, the camera 211 may be configured to capture a left side view image of the bonding structure 20.

[0082] Although it is not shown in Figures, it should be understood that the second configuration in the second example of the second embodiment may further include a third arrangement and a fourth arrangement of the system 200. In the third arrangement, the first sub-module 210 may be moved to a front position along the positive x-axis direction such that the mirror 221c of the second reflection component 221 is arranged to reflect light from the bonding structure 20 in a third instance of the second direction to the first reflection component 213 to conduct a front view inspection of the bonding structure 20, e.g. capture a front view image of the bonding structure 20 . In the fourth arrangement, the first sub-module 210 may be moved to a rear position along the negative x-axis direction such that the mirror 221 d of the second reflection component 221 is arranged to reflect light from the bonding structure 20 in a fourth instance of the second direction to the first reflection component 213 to conduct a rear view inspection of the bonding structure 20, e.g. capture a rear view image of the bonding structure 20.

[0083] Similar to the first embodiment, when the first/second sub-module 210/220 is moved to arrange the system 200 in the second configuration, the second configuration may include four different arrangements of the system 200. Each arrangement corresponds to a different instance of the second direction. In each of the four arrangements, the system 200 may be used to conduct a different view inspection of the bonding structure 20, e.g. capture a different view image of the bonding structure 20. [0084] In the first and the second embodiments of the invention, the second reflection component includes four different mirrors disposed at different positions. Accordingly, the second configuration includes four different arrangements of the system. It should be noted that in other embodiments, the number of the arrangements may vary depending on the shape, structure and/or number of sub-components of the second reflection component.

[0085] Figure 4 is a front sectional view of a third system 300 for multi view inspection of a bonding structure 30 according to a third embodiment of the invention. The difference between the third embodiment and the first embodiment shown in Figures 1 (a) to 1 (e) is that the first sub-module 310 of the third system 300 may further include a complementary camera 314 and a beam splitter 315. [0086] The beam splitter 315 is disposed between the first reflection component 313 and the camera 311 , and configured to split light from the first reflection component 313 into a first beam and a second beam, wherein the first beam is provided to the camera 311 and the second beam is provided to the complementary camera 314. The complementary camera 314 is arranged to receive the second beam to conduct the first view inspection of the bonding structure 30 when the third system 300 is in the first configuration and conduct the second view inspection of the bonding structure 30 when the third system 300 is in the second configuration. [0087] To change the direction of the second beam, the third system 300 may further include a third reflection component 316 configured to reflect the second beam from the beam splitter 315 to the complementary camera 314. The third reflection component 316 may include a mirror.

[0088] It should be noted that complementary camera 314, beam splitter 315 and the third reflection component 316 may also be used in the second embodiment similarly. It will not be described in detail here.

[0089] The complementary camera 314, beam splitter 315 and the third reflection component 316 may be moved together with other components of the first sub-module 310 when the third system 300 is moved between the first configuration and the second configuration. Alternatively, in some embodiments of the invention, to move the third system 300 between the first configuration and the second configuration, maybe only part of the first sub-module 310 is moved, e.g. maybe only the first light source 312 and the first reflection component 313 are moved to change the configuration of the third system 300.

[0090] Embodiments of the invention also provide a method for multi-view inspection of a bonding structure. The method includes providing a system for multi-view inspection of a bonding structure, wherein the system may at least include a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module at least including a second reflection component. The second sub-module is disposed between the first sub- module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or at least part of the second sub- module is arranged to be movable between a first configuration and a second configuration. In the first configuration, the first reflection component is arranged to provide light from the bonding structure in a first direction to the camera, while in the second configuration, the second reflection component is arranged to provide, through the first reflection component, light from the bonding structure in a second direction to the camera; and conducting a first view inspection of the bonding structure when the system is in the first configuration and conducting a second view inspection of the bonding structure when the system is in the second configuration. [0091] In some embodiments of the invention, the method may further comprises: prior to conducting the second view inspection of the bonding structure, moving at least part of the first sub-module and/or at least part of the second sub-module along a third direction in a plane perpendicular to the first direction to dispose the system in the second configuration.

[0092] In some embodiments of the invention, the third direction may include a first possible direction and a second possible direction in a plane perpendicular to the first direction. Accordingly, the step of moving at least part of the first sub-module and/or at least part of the second sub-module along the third direction comprises: moving the at least part of the first sub-module and/or the at least part of the second sub-module along the first possible direction to dispose the system in a first arrangement of the second configuration; moving the at least part of the first sub-module and/or the at least part of the second sub-module along the second possible direction to dispose the system in a second arrangement of the second configuration.

[0093] In one example, the third direction includes a positive x-axis direction, a negative x-axis direction, a positive y-axis direction, and a negative y-axis direction in the plane perpendicular to the positive z-axis direction. Accordingly, the step of moving at least part of the first sub-module and/or at least part of the second sub-module along a third direction may comprise: moving the at least part of the first sub-module and/or the at least part of the second sub-module along each of the positive x-axis direction, the negative x- axis direction, the positive y-axis direction, and the negative y-axis direction to dispose the system in four different arrangements of the second configuration respectively. In this example, the second configuration includes four different arrangements and each arrangement of the second configuration provides a different second direction from the bonding structure to the second reflection component.

[0094] In some embodiments, the step of conducting a first view inspection of the bonding structure may include: capturing a first view image of the bonding structure, e.g. a top view image of the bonding structure; and the step of conducting a second view inspection of the bonding structure may include: capturing at least one second view image of the bonding structure, e.g. a left side view image, a right side view image, a front view image and/or a rear view image of the bonding structure. In some embodiments, the system may further include a complementary camera and a beam splitter configured to split light from the first reflection component into a first beam and a second beam, wherein the first beam is provided to the camera and the second beam is provided to the complementary camera, accordingly the method may further comprise: conducting a first view inspection of the bonding structure through the complementary camera when the system is in the first configuration; and conducting a second view inspection of the bonding structure through the complementary camera when the system is in the second configuration.

In some embodiments of the invention, the complementary camera is configured to capture a first view image of the bonding structure with a predetermined resolution, e.g. a resolution higher than that of the camera, when the system is in the first configuration, and capture at least one second view image of the bonding structure with a predetermined resolution when the system is in the second configuration.

In some embodiments of the invention, the method may further include: conducting, by a processing device, at least one of the following to determine information, e.g. depth information, about the bonding structure: identifying a sagging wire and/or a shorted wire based on the at least one second view image of the bonding structure; calculating solder ball height, wire loop height and/or fillet height based on the at least one second view image of the bonding structure; and calculating bond line thickness and/or die tilt based on information obtained from both the first view image and the at least one second view image of the bonding structure.

[0095] Figure 5 is a flow chart illustrating the method 500 for multi-view inspection of a bonding structure according to one embodiment of the invention In this embodiment, the second sub-module of the system is moved to dispose the system in the second configuration which includes four different arrangements of the system.

[0096] In block 501, a system for multi-view inspection of a bonding structure, e.g. the first system 100/ the second system 200/ the third system 300, is provided. In this embodiment, the system is arranged in the first configuration at the start. [0097] In block 502, the camera of the first sub-module is used to capture a top view image of the bonding structure.

[0098] In block 503, the second sub-module is moved from a first or home position to a right position along the positive y-axis direction so that the system is arranged in a first arrangement of a second configuration.

[0099] In block 504, the camera of the first sub-module is used to capture a right side view image of the bonding structure.

[0100] In block 505, the second sub-module is moved to a left position along the negative y-axis direction so that the system is arranged in a second arrangement of the second configuration.

[0101] In block 506, the camera of the first sub-module is used to capture a left side view image of the bonding structure.

[0102] In block 507, the second sub-module is moved to a front position along the positive x-axis direction so that the system is arranged in a third arrangement of the second configuration.

[0103] In block 508, the camera of the first sub-module is used to capture a front view image of the bonding structure.

[0104] In block 509, the second sub-module is moved to a rear position along the negative x-axis direction so that the system is arranged in a fourth arrangement of the second configuration. [0105] In block 510, the camera of the first sub-module is used to capture a rear view image of the bonding structure.

[0106] In block 511 , the system determines information of the bonding structure based on the top view image, the left side view image, the right side view image, the front view image and/or the rear view image of the bonding structure.

[0107] It should be noted that the embodiment shown in Figure 5 is for illustration purpose only, does not intend to limit the scope of the invention. For example, the number of different views of the bonding structure to be inspected and the sequence of inspecting different views of the bonding structure may vary according to actual requirements and needs; the whole or part of the first sub- module and/or the whole or part of the second sub-module may be moved to arrange the system in the second configuration in other embodiments. The system may include at least one light source, e.g. the system may only include a coaxial light in the first sub-module, or further include a ring light and/or a dome light.

[0108] It is to be appreciated from the description above that the system and method for multi-view inspection proposed by embodiments of the invention are relatively simple and cost-effective since the system may only include one camera, one light source and two reflection components, and a bonding structure may be inspected from different views with the proposed system and method only by moving part of the system. Further, the system is very easy to be set up to conduct a multi-view inspection of a bonding structure. [0109] It is to be understood that the embodiments and features described above should be considered exemplary and not restrictive. Many other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the invention. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. Furthermore, certain terminology has been used for the purposes of descriptive clarity, and not to limit the disclosed embodiments of the invention.

Claims

1 . A system for multi-view inspection of a bonding structure, the system comprising: a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub- module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or at least part of the second sub-module is arranged to be movable between a first configuration and a second configuration; when in the first configuration, the first reflection component is arranged to provide light from the bonding structure in a first direction to the camera to conduct a first view inspection of the bonding structure; and when in the second configuration, the second reflection component is arranged to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection of the bonding structure.

2. The system according to claim 1 , wherein the at least part of the first sub-module and/or the at least part of the second sub-module is arranged to be movable along a third direction in a plane perpendicular to the first direction to dispose the system in the second configuration.

3. The system according to claim 2, wherein the third direction includes a first possible direction and a second possible direction in the plane perpendicular to the first direction, and the at least part of the first sub-module and/or at least part of the second sub-module is arranged to be movable along the first possible direction to dispose the system in a first arrangement of the second configuration; and movable along the second possible direction to dispose the system in a second arrangement of the second configuration.

4. The system according to claim 3, wherein the first direction is the positive z-axis direction and the third direction includes a positive x-axis direction, a negative x-axis direction, a positive y-axis direction, and a negative y-axis direction in a plane perpendicular to a positive z-axis direction, and the at least part of the first sub-module or the at least part of the second sub-module is arranged to be movable along each of the positive x-axis direction, the negative x-axis direction, the positive y-axis direction, and the negative y-axis direction to dispose the system in four different arrangements of the second configuration respectively.

5. The system according to any one of claim 1 to claim 4, wherein the camera is arranged such that its optical axis is substantially perpendicular to the first direction; wherein the first reflection component is disposed between the first light source and the second reflection component in the first direction; when in the first configuration, the first reflection component is arranged to allow the light from the first light source to transmit to the placement area, and provide light from the bonding structure in the first direction to the camera to conduct the first view inspection, when in the second configuration, the first reflection component is arranged to reflect the light from the second reflection component in the first direction to the camera to conduct the second view inspection.

6. The system according to any one of claim 1 to claim 4, wherein the camera is arranged such that its optical axis is directed to the placement area; and wherein the first reflection component is disposed between the camera and the second reflection component in the first direction; when in the first configuration, the first reflection component is arranged to reflect light from the first light source to the placement area, and allow the light from the bonding structure in the first direction to transmit to the camera; when in the second configuration, the first reflection component is arranged to allow the light reflected from the second reflection module in the first direction to transmit to the camera.

7. The system according to any preceding claim, wherein the first light source includes a coaxial light.

8. The system according to any preceding claim, wherein the first reflection component includes a beam splitter.

9. The system according to any preceding claim, wherein the second sub- module further comprises a second light source which is disposed between the second reflection component and the placement area, wherein the second light source includes a ring light or a low-angle light.

10. The system according to claim 9, wherein the second sub-module further comprises a third light source which is disposed on the second light source to provide uniform illumination and improve contrast of features of the bonding structure, wherein the third light source includes a dome light.

11. The system according to claim 10, wherein the second reflection component is disposed on the third light source.

12. The system according to any preceding claim, wherein the second reflection component includes at least one mirror, wherein each of the at least one mirror is disposed at a predetermined angle with respect to an axis along the first direction.

13. The system according to claim 12, wherein the second reflection component includes four mirrors and each mirror is disposed along an edge of a rectangle/square and at an angle of about 22.5 degrees with respect to an axis along the first direction.

14. The system according to any preceding claim, further comprising a first movable platform on which the at least part of the first sub-module is disposed, wherein the first movable platform is arranged to be movable to dispose the system in the first configuration or the second configuration.

15. The system according to any preceding claim, further comprising a second movable platform on which the at least part of the second sub-module is disposed, wherein the second movable platform is arranged to be movable to dispose the system in the first configuration or the second configuration.

16. The system according to claim 14 or claim 15, wherein the first movable platform and/or the second movable platform includes a linear XY table.

17. The system according to any preceding claim, further comprising a complementary camera and a beam splitter, wherein the beam splitter is disposed between the first reflection component and the camera, and configured to split light from the first reflection component into a first beam and a second beam, wherein the first beam is provided to the camera and the second beam is provided to the complementary camera; the complementary camera is arranged to receive the second beam to conduct the first view inspection of the bonding structure when in the first configuration, and the second view inspection when in the second configuration.

18. The system according to claim 17, further comprising a third reflection component configured to reflect the second beam from the beam splitter to the complementary camera.

19. The system according to any preceding claim, wherein the camera is configured to capture a first view image of the bonding structure when conducting the first view inspection and at least one second view image of the bonding structure when conducting the second view inspection.

20. The system according to any one of claim 17 to claim 19, wherein the complementary camera is further configured to capture a first view image of the bonding structure with a predetermined resolution when conducting the first view inspection; and capture at least one second view image of the bonding structure with a predetermined resolution when conducting the second view inspection.

21. The system according to claim 19 or claim 20, wherein the system further comprises a processing device configured to determine information about the bonding structure based on the acquired first view image and the at least one second view image.

22. The system according to claim 21 , wherein the first view image includes a top view image of the bonding structure and the at least one second view image includes a left side view image, a right side view image, a front view image and/or a rear view image of the bonding structure.

23. The system according to claim 21 or claim 22, wherein the processing device is further configured to conduct at least one of the following to determine information about the bonding structure: identify a sagging wire and/or a shorted wire based on the at least one second view image of the bonding structure; calculate solder ball height, wire loop height and/or fillet height based on the at least one second view image of the bonding structure; and calculate bond line thickness and/or die tilt based on information obtained from both the first view image and the at least one second view image of the bonding structure.

24. A method for multi-view inspection of a bonding structure, the method comprising: providing a system comprising a first sub-module including a camera, a first light source and a first reflection component, and a second sub-module including a second reflection component, wherein the second sub-module is disposed between the first sub-module and a placement area in which the bonding structure is to be disposed, and at least part of the first sub-module and/or the second sub-module are movable between a first configuration and a second configuration; when in the first configuration, the first reflection component is configured to provide light from the bonding structure in a first direction to the camera to conduct a first view inspection of the bonding structure; and when in the second configuration, the second reflection component is configured to provide, through the first reflection component, light from the bonding structure in a second direction to the camera to conduct a second view inspection of the bonding structure; and conducting the first view inspection of the bonding structure when the system is in the first configuration and conducting the second view inspection when the system is in the second configuration.

25. The method according to claim 24, further comprising: prior to conducting the second view inspection, moving at least part of the first sub-module and/or at least part of the second sub-module along a third direction in a plane perpendicular to the first direction to dispose the system in the second configuration.

26. The method according to claim 25, wherein the third direction includes a first possible direction and a second possible direction in the plane perpendicular to the first direction, wherein the step of moving at least part of the first sub-module and/or at least part of the second sub-module along a third direction comprises: moving the at least part of the first sub-module and/or the at least part of the second sub-module along the first possible direction to dispose the system in a first arrangement of the second configuration; and moving the at least part of the first sub-module and/or the at least part of the second sub-module along the second possible direction to dispose the system in a second arrangement of the second configuration.

27. The method according to claim 26, wherein the first direction is the positive z-axis direction, and the third direction includes a positive x-axis direction, a negative x-axis direction, a positive y-axis direction, and a negative y-axis direction in the plane perpendicular to the positive z-axis direction, wherein the step of moving at least part of the first sub-module and/or at least part of the second sub-module along a third direction comprises: moving the at least part of the first sub-module and/or the at least part of the second sub-module along each of the positive x-axis direction, the negative x-axis direction, the positive y-axis direction, and the negative y-axis direction to dispose the system in four different arrangements of the second configuration respectively.

28. The method according to any one of claim 24 to claim 27, wherein the step of conducting the first view inspection of the bonding structure comprises: capturing a first view image of the bonding structure; wherein the step of conducting the second view inspection of the bonding structure comprises: capturing at least one second view image of the bonding structure.

29. The method according to any one of claim 24 to claim 28, wherein the system further comprises a complementary camera and a beam splitter configured to split light from the first reflection component into a first beam and a second beam, wherein the first beam is provided to the camera and the second beam is provided to the complementary camera; wherein the method further comprises: conducting a first view inspection of the bonding structure through the complementary camera when the system is in the first configuration; and conducting a second view inspection of the bonding structure through the complementary camera when the system is in the second configuration.

30. The method according to claim 29, wherein the step of conducting a first view inspection of the bonding structure through the complementary camera comprises: capturing a first view image of the bonding structure with a predetermined resolution through the complementary camera; wherein the step of conducting a second view inspection of the bonding structure through the complementary camera comprises: capturing at least one second view image of the bonding structure with a predetermined resolution through the complementary camera.

31. The method according to any one of claim 28 to claim 30, wherein the first view image of the bonding structure includes a top view image of the bonding structure, and the at least one second view image of the bonding structure includes a left side view image, a right side view image, a front view image and/or a rear view image of the bonding structure.

32. The method according to any one of claim 28 to claim 31 , further comprising: conducting, by a processing device, at least one of the following to determine information about the bonding structure: identifying a sagging wire and/or a shorted wire based on the at least one second view image of the bonding structure; calculating solder ball height, wire loop height and/or fillet height based on the at least one second view image of the bonding structure; and calculating bond line thickness and/or die tilt based on information obtained from both the first view image and the at least one second view image of the bonding structure.