Inspection system

Abstract

Embodiments of the present disclosure generally relate to inspection systems for substrates or wafers for solar cell applications. The inspection system is configured to analyze notches, cracks, and other defects of the substrate or wafer. The system includes conveyor equipment, and the conveyor equipment includes one or more conveyor elements. The conveyor elements are configured to transport rectangular wafers having a width between about 175 mm and about 250 mm. The conveyor elements include a first conveyor belt and a second conveyor belt to transport the substrate. The spacing of the belts reduces vibrations at the edges of the substrate.

Description

Background Technical Field

[0002] Embodiments of the present disclosure generally relate to a conveyor system and, more particularly, to an inspection system having a conveyor system. Background Art

[0004] Substrates (such as semiconductor substrates, large area substrates for display panels, solar cell substrates, and the like) are routinely inspected at separate inspection stations during processing to ensure compliance with predetermined quality control standards. Different inspection techniques provide comprehensive data about the product and the process. However, due to the number of inspection stations required and the transfer time associated with moving substrates between inspection stations, comprehensive inspection can be time-consuming, thereby reducing throughput. Thus, device manufacturers often face the decision of choosing between thorough inspection with unaffordable inspection / transfer times or foregoing some of the aforementioned inspection processes.

[0005] Typical substrate test systems can process approximately 3,600 substrates per hour in a linear arrangement. However, as inspection processes continue to reduce the amount of time to complete inspection steps, substrate handling equipment is needed within the test system that can keep up with faster inspection times and / or additional inspection routines. Generally, the test system includes inspection equipment that identifies solar cell substrates having undesired defects, thereby removing the substrates from the test system. Solar cell substrates are rectangular, thinner, and less rigid compared to conventional large area substrates for display panels, and thus inspection systems for large area substrates may not be suitable for solar cell substrates.

[0006] One drawback is that conventional test systems are not configured to accurately inspect rectangular substrates moving at high speed rates. In conventional test systems, rectangular large area substrates are prone to large vibrations at the substrate edges when moving quickly. When the edges of the substrate vibrate, the image quality of the substrate edges acquired by vision inspection equipment is typically poor. This poor image quality increases false positives or negatives of substrate damage, resulting in substrates being inaccurately identified as good or damaged and making substrate inspection undesirably unreliable.

[0007] Accordingly, there is a need in the art for an improved inspection system. Summary of the Invention

[0008] Embodiments herein generally relate to a conveyor system that conveys rectangular substrates with vibrations tolerable for vision inspection. Embodiments herein also generally relate to an inspection system for rectangular substrates for solar cell applications. The inspection system disclosed herein is configured to accurately image edge defects in rectangular substrates.

[0009] In one example, a system is provided for inspecting a rectangular wafer having a width between approximately 175 mm and approximately 250 mm. The system includes: one or more metrology stations configured to inspect the rectangular wafer; and a conveyor system configured to transport the rectangular wafer while the one or more metrology stations inspect the rectangular wafer. The conveyor system includes a first conveyor device and a second conveyor device. Each of the first conveyor device and the second conveyor device includes one or more conveyor elements. The one or more conveyor elements include a first conveyor belt and a second conveyor belt parallel to the first conveyor belt. The first conveyor belt and the second conveyor belt are configured to transport a rectangular wafer having a width between approximately 175 mm and approximately 250 mm in the direction of travel when the width of the substrate is orthogonal to the direction of travel. The first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm.

[0010] In another example, a system is provided for inspecting a rectangular wafer having a width between approximately 175 mm and approximately 250 mm. The system includes: a front end; one or more metrology stations configured to inspect the rectangular wafer; and a conveyor system configured to transport the rectangular wafer while the one or more metrology stations inspect the rectangular wafer. The conveyor system includes a first conveyor device and a second conveyor device. Each of the first conveyor device and the second conveyor device includes one or more conveyor elements. The one or more conveyor elements include a first conveyor belt and a second conveyor belt parallel to the first conveyor belt. The first conveyor belt and the second conveyor belt are configured to transport a rectangular wafer having a width between approximately 175 mm and approximately 250 mm in the direction of travel when the width of the substrate is orthogonal to the direction of travel. The first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm. The front end is configured to transport the rectangular wafer to the conveyor system.

[0011] In yet another example, a method of transporting a rectangular wafer having a transport width between about 175 mm and about 250 mm is provided. The method includes: transporting a rectangular substrate on a conveyor system; and transporting the rectangular substrate to a rotary sorting system. The conveyor system includes a first conveyor device and a second conveyor device. Each of the first conveyor device and the second conveyor device includes one or more conveyor elements. The one or more conveyor elements include a first conveyor belt and a second conveyor belt parallel to the first conveyor belt. The first conveyor belt and the second conveyor belt are configured to transport a rectangular wafer having a width between about 175 mm and about 250 mm in the direction of travel when the width of the substrate is orthogonal to the direction of travel. The first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm. The rectangular substrate is transported on the conveyor system at a speed between about 300 m / s and about 600 m / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To understand the above-described features of the present disclosure in detail, a more particular description of the present disclosure briefly summarized above may be obtained by reference to the embodiments, some of which are illustrated in the drawings. It should be noted, however, that the drawings illustrate only exemplary embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure, since the present disclosure may be applied to other equivalent embodiments.

[0013] Figure 1A A top plan view of an inspection (e.g., testing) system according to one embodiment is illustrated.

[0014] Figure 1B A top plan view of a conveyor system according to one embodiment is illustrated.

[0015] Figure 1C is a flowchart of a method for transporting a rectangular substrate according to one embodiment.

[0016] Figure 2 A top plan view of a high-speed rotary sorter according to one embodiment is illustrated.

[0017] Figure 3A A top plan view of a conveyor inspection system according to one embodiment is illustrated.

[0018] Figure 3B A side plan view of a conveyor inspection system in a first orientation according to one embodiment is illustrated.

[0019] Figure 3C A side plan view of a conveyor inspection system in a second orientation according to one embodiment is illustrated.

[0020] Figure 4Is a flowchart of operations of a method for sorting substrates according to one embodiment.

[0021] Figure 5A Illustrates a side view plan view of a substrate rotator in a first orientation according to one embodiment.

[0022] Figure 5B Illustrates a top view plan view of a substrate rotator in a first orientation according to one embodiment.

[0023] Figure 5C Illustrates a side view plan view of a substrate rotator in a second orientation according to one embodiment.

[0024] Figure 5D Illustrates a top view plan view of a substrate rotator in a second configuration according to one embodiment.

[0025] Figure 5E Illustrates a side view plan view of a substrate rotator in a third configuration according to one embodiment.

[0026] Figure 5F Illustrates a top view plan view of a substrate rotator in a third configuration according to one embodiment.

[0027] Figure 6 Is a flowchart of operations of a method for performing metrology on a substrate according to one embodiment.

[0028] Figure 7A Illustrates a schematic view of a body rotating in a first direction according to one embodiment.

[0029] Figure 7B Illustrates a schematic view of a body rotating in a second direction according to one embodiment.

[0030] Figure 7C Illustrates a schematic view of a body rotating in a first direction according to one embodiment.

[0031] Figure 7D Illustrates a schematic view of a body rotating in a second direction according to one embodiment.

[0032] For ease of understanding, the same reference numerals have been used, wherever possible, to identify common elements among the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. Detailed Description

[0033] Embodiments of the present disclosure generally relate to a conveyor system that conveys a rectangular substrate with vibrations tolerable for visual inspection. Embodiments of the present disclosure also generally relate to an inspection system for a rectangular substrate for solar cell applications. The inspection system disclosed herein is configured to accurately image edge defects in a rectangular substrate. The inspection system is configured to analyze notches, cracks, and other defects in a rapidly moving rectangular substrate. The inspection system includes a conveyor system, and the conveyor system includes one or more conveyor elements. The conveyor elements are configured to transport a rectangular substrate having a large width (i.e., a dimension of the substrate orthogonal to the direction of travel along the conveyor element). The conveyor elements include belts for transporting the substrate. The spacing of the belts is selected to reduce vibrations at the edges of the substrate. Reducing vibrations at the edges of the substrate allows for more accurate imaging of the edges of the substrate. If the edges of the substrate are accurately imaged, false positives or false negatives in imaging the sides of the substrate are reduced, thereby reducing waste of substrates inaccurately identified as damaged. The embodiments disclosed herein can be used in, but are not limited to, inspection systems for measuring defects in rectangular solar cell substrates.

[0034] As used herein, the term "about" means a + / - 10% variation relative to a nominal value. It should be understood that such variations can be included in any value provided herein.

[0035] Figure 1A FIG. 1 is a top plan view of an inspection system (alternatively referred to as a test system, or system) 100 according to one embodiment. The inspection system 100 is configured to inspect and sort a plurality of substrates (alternatively referred to as wafers) 110. As shown, the inspection system 100 includes a front end 102, a conveyor system 114, a modular inspection unit 104, a sorting unit 106, and a controller 190. The front end 102 can be a loading unit. The conveyor system 114 is configured to transport the substrates 110 from the loading unit (e.g., the front end 102) to the modular inspection unit 104. The modular inspection unit 104 can be a metrology unit. The sorting unit 106 can be a sorting module that uses grippers to transfer the substrates into bins based on information obtained from instructions for the substrates in the inspection unit 104. The front end 102, the modular inspection unit 104, and the sorting unit 106 can be linearly arranged relative to each other, e.g., where the conveyor system 114 extends through the front end 102, the modular inspection unit 104, and the sorting unit 106 of the inspection system 100 in a linear or substantially linear orientation. Alternatively, the front end 102, the modular inspection unit 104, and the sorting unit 106 can be arranged in another orientation, such as an "L-shape".

[0036] The front end 102 is configured to transport the substrate 110 to the remainder of the inspection system 100 via the conveyor system 114. As shown, the conveyor system 114 includes a first conveyor device 115, an intermediate conveyor device 117, and a second conveyor device 119. Each of the first conveyor device 115, the intermediate conveyor device 117, and the second conveyor device 119 includes one or more conveyor elements 160. The conveyor system 114 and thus the first conveyor device 115, the intermediate conveyor device 117, and the second conveyor device 119 may further include any device configured to carry the substrate through the inspection system 100. For example, each of the conveyor elements 160 may include a belt, a roller, a web, or one or more of other devices / machineries suitable for transporting the substrate through the inspection system 100. The conveyor system 114 may further include a carrier or a pallet to hold the substrate while moving along the conveyor element 160, wherein the carrier or the pallet is moved by a drive mechanism. Each of the first conveyor device 115, the intermediate conveyor device 117, and the second conveyor device 119 may be driven individually.

[0037] The intermediate conveyor device 117 is part of the conveyor inspection system 170. The conveyor inspection system 170 is configured to sort out the undesired substrates 110 before the substrates can enter the modular inspection unit 104 of the inspection system 100 and remove the undesired substrates from the conveyor system 114. The conveyor inspection system 170 is also configured to transfer the substrates 110 suitable for further testing and / or inspection to the second conveyor device 119 for transportation to the modular inspection unit 104. More details about the conveyor inspection system 170 are given in the description of FIG. 3 below.

[0038] The conveyor system 114 may be a motor-driven conveyor system and may include one or more conveyors, such as a conveyor belt or a track driven by an actuator through rollers and / or drive gears. The conveyor system 114 may be arranged in a linear layout to convey the substrate through the modular inspection unit 104. As such, the conveyor system 114 is disposed within the modular inspection unit 104 and facilitates the conveyance of the substrate 110 through the modular inspection unit 104. Additional modular inspection units may be positioned between the front end 102 and the modular inspection unit 104, and / or between the modular inspection unit 104 and the sorting unit 106, and / or after the sorting unit 106 to facilitate the expansion of the inspection system 100.

[0039] As shown, the front end 102 includes a transfer robot 108. The transfer robot 108 is configured to transfer a substrate 110 from one or more cassettes 112 positioned within the front end 102 to a first conveyor device 115. The substrate loaded on the first conveyor device 115 is transferred to an intermediate conveyor device 117 and to a second conveyor device 119 for further transport to the modular inspection unit 104. The transfer robot 108 includes a support element 108E, such as a suction element, an end effector, and a gripper fixture for gripping and transferring the substrate 110.

[0040] The front end 102 receives one or more cassettes 112. Each cassette 112 contains substrates 110 in a stacked configuration. The substrates 110 can be stacked horizontally or vertically. For example, each cassette 112 includes a plurality of slots in the cassette, and each slot is configured to hold a substrate 110. The cassettes 112 can be positioned such that the substrates 110 are positioned one above the other. The substrates 110 are transferred from the cassettes 112 to the conveyor system 114 via the transfer robot 108 for conveyance through the inspection system 100 via the conveyor system. The front end 102 includes a controller 190. The controller 190 can include a graphical user interface adapted to present information related to operations occurring in the front end 102, including process metrics, lot numbers, and similar information. In one example, the controller 190 includes a touch screen interface.

[0041] The modular inspection unit 104 is configured to perform one or more measurements on the substrate 110 passing through the modular inspection unit 104. As shown, the modular inspection unit 104 includes one or more metrology stations 116, a substrate edge metrology system 181, and a substrate rotator 180. The conveyor system 114 is configured to transport the substrate 110 while the substrate is being inspected at one or more metrology stations 116. In Figure 1A an embodiment, the modular inspection unit 104 includes five metrology stations 116A to 116E, two of which are part of the substrate edge metrology system 181. In Figure 1A the embodiment depicted, the metrology stations 116D and 116E separated by the substrate rotator 180 are part of the substrate edge metrology system 181. It is envisioned that, where space permits, the inspection system 100 can be modified by adding or reducing metrology stations to the modular inspection unit 104 rather than adding a second modular inspection unit, thereby increasing throughput and / or the number of metrology processes performed.

[0042] The metrology station 116 may include any one of the following: a micro-crack inspection unit, a thickness measurement unit, a resistivity measurement unit, a photoluminescence unit, a geometry inspection unit, a sawmark detection unit, a stain detection unit, a notch detection unit, and / or a crystal fraction detection unit. The micro-crack inspection unit may be configured to inspect whether the substrate is cracked and to determine the crystal fraction of the substrate. The geometry inspection unit may be configured to analyze the surface properties of the substrate. The sawmark detection unit may be configured to identify sawmarks on the substrate, including grooves, steps, and double-step marks. In addition to those listed above, the metrology station 116 may also include other examples. As described in detail below, each of the metrology stations 116 is used to transfer one or more metrology values to the sorting unit 106.

[0043] The metrology station 116B may be a thickness measurement unit adapted to measure the thickness of the substrate. The metrology station 116B may also measure the resistivity of the substrate 110 or alternatively measure the resistivity of the substrate 110. The metrology station 116B receives the substrate 110 conveyed along the conveyor system 114 after being inspected in the metrology station 116A, which is any type of metrology station. The metrology station 116B is disposed downstream of the metrology station 116A in an in-line path of the substrate 110 defined by the conveyor system 114. The metrology station 116B performs one or more inspection processes on the substrate 110. The inspection processes occurring at the metrology station 116B may be performed while the substrate is in motion. It is contemplated that the motion of the substrate 110 may be stopped at the metrology station 116B to facilitate improved inspection accuracy.

[0044] The metrology station 116C may be a photoluminescence unit configured to detect defects and / or perform impurity measurements. Additionally, another metrology station (not shown) may be a geometry inspection unit configured to analyze the geometry and surface properties of the substrate 110.

[0045] Metrology station 116C receives the substrate 110 that is conveyed along the conveyor system 114 after being inspected in metrology station 116B. Metrology station 116D receives the substrate 110 that is conveyed along the conveyor system 114 after being inspected in metrology station 116C. Metrology station 116E receives the substrate 110 that is conveyed along the conveyor system 114 after being inspected in metrology station 116D, and so on if additional metrology units are utilized in the linear path as shown. Additionally, in some embodiments, non-linear path inspection is utilized. Accordingly, the substrate 110 can be conveyed between metrology stations 116A - 116E in a non-linear manner, such as in a circular manner or in a bow-shaped manner. Substrate rotator 180 picks up the substrate leaving metrology station 116D on the conveyor system 114, rotates the substrate, and then returns the rotated substrate to the conveyor system 114 for transportation to metrology station 116E.

[0046] Substrate edge metrology system 181 is configured to measure defects on the edge of substrate 110. As shown, the substrate edge metrology system includes metrology stations 116D, 116E, and substrate rotator 180. According to one embodiment, metrology stations 116D, 116E are both chip side inspection (CSI) tools. The CSI tool includes image acquisition devices, such as cameras, charge-coupled devices (CCDs), and the like, which are adapted to acquire images of each side of the substrate 110 as the substrate passes through metrology stations 116D, 116E to inspect for notches, cracks, or other defects on the said side of the substrate. The CSI tool is configured to image the side of the substrate 110 that is parallel to the direction in which the substrate moves downstream along the conveyor system 114. In Figure 1A the example illustrated, each metrology station 116D, 116E has a CSI tool that is positioned to obtain images of two opposite sides of the substrate, typically the sides of the substrate having an orientation parallel to the direction in which the substrate travels along a portion of the conveyor system 114 disposed within the inspection unit 104. In one example, the CSI tool is positioned to obtain images of two opposite sides of the substrate while the substrate is held on the conveyor system 114 within metrology stations 116D, 116E.

[0047] The substrate rotator 180 is disposed between the metrology stations 116D and 116E. In the first metrology station 116D, nicks, cracks, or other defects on the side of the substrate (i.e., not the leading or trailing edge when the substrate is on the conveyor system 114) are inspected. After the substrate 110 passes through the first metrology station 116D, the substrate rotator 180 rotates the substrate 110 about the central axis of the substrate by approximately 90 degrees or approximately 270 degrees while translating the substrate 180 degrees. By translating the substrate 180 degrees, the substrate can be picked up and placed at a position substantially the same as other substrates on the conveyor system 114 while the substrate is traveling at a high rate along the conveyor system 114. In other words, the substrate rotator 180 has a substrate pick-up position above a first position above the conveyor system 114 and a substrate drop position above a second position above the conveyor system 114, where the substrate rotator 180 translates (i.e., rotates) 180 degrees between the first position and the second position above the conveyor system 114. Additionally, depending on the direction in which the substrate rotator 180 rotates 180 degrees, the substrate rotates about the central axis of the substrate by approximately 90° or approximately 270°, such that the same edge (leading or trailing edge) of the substrate is placed in the same orientation on the conveyor system 114 regardless of the direction of the rotational translation. In other words, when the substrate rotator 180 rotates 180 degrees between the first position and the second position, the substrate rotates 90 degrees. This exposes the unmeasured sides of the substrate 110 (i.e., the leading and trailing edges before being rotated by the substrate rotator 180) to the metrology station 116E, where an inspection is performed to detect nicks, cracks, or other defects. Thus, each side of the substrate 110 is inspected by the CSI tool. More details of the substrate rotator appear in the following discussion of Figure 4 the substrate rotator are presented.

[0048] The conveyor system 114 conveys the inspected substrate 110 from the modular inspection unit 104 to the sorting unit 106. The sorting unit 106 is configured to sort the substrate 110 into different categories according to the metrology values of each substrate found in the metrology stations 116 in the modular inspection unit 104. As shown, the sorting unit 106 includes a rotary sorting system 120. The conveyor system 114 delivers the inspected substrate 110 to a position accessible by the rotary sorting system 120 in the sorting unit 106. Additionally, the conveyor system 114 can continue through the sorting unit 106 to reach the connector 150. Thus, if the sorting unit 106 is not sorting the substrate 110, the inspected substrate 110 bypasses the rotary sorting system 120 of the sorting unit 106. Additionally, if the inspected substrate 110 is not picked up by the rotary sorting system 120, the substrate continues along the conveyor system 114 toward the connector 150.

[0049] In some embodiments, substrates not picked up by the rotary sorting system 120 continue along the conveyor system 114, which leads to the unsorted substrate bin. In some embodiments, the sorting unit 106 is further connected via the connector 150 to additional units such as additional inspection systems, additional sorting units, and / or additional metrology units. The connector 150 may further allow alignment of the conveyor system 114 with the conveyor systems of the additional units such as additional inspection systems, additional sorting units, and / or additional metrology units.

[0050] The controller 190 is configured to control the inspection system 100 and automate the inspection system. The controller 190 may be coupled to or communicate with one or more of the conveyor system 114, the front end 102, the modular inspection unit 104, the sorting unit 106, the transfer robot 108, the conveyor inspection system 170, the substrate spinner 180, and / or the metrology stations 116A - 116E. The inspection system 100 may provide information to the controller 190 regarding substrate movement, substrate transfer, substrate sorting, and / or metrology performed.

[0051] The controller 190 includes a central processing unit (CPU) (not shown), a memory (not shown), and support circuitry (or I / O) (not shown). The CPU is one of any form of computer processor used in an industrial environment to control various processes and hardware (e.g., pattern generators, motors, and other hardware) and monitor processes (e.g., processing time and substrate position or orientation). The memory (not shown) is connected to the CPU and is one or more of readily accessible memories such as random access memory (RAM), read only memory (ROM), floppy disks, hard disks, or any other form of digital storage device (local or remote). Software instructions and data may be encoded and stored in the memory to direct the CPU. The support circuitry (not shown) is also connected to the CPU to support the processor in a conventional manner. The support circuitry includes conventional cache, power supply, clock circuits, input / output circuits, subsystems, and the like. A program (or computer instructions) readable by the controller 190 determines what tasks can be performed on the substrate. The program may be software readable by the controller 190 and may include code to monitor and control, for example, processing time and the position or orientation of the substrate within the inspection system 100.

[0052] Figure 1B FIG. shows a top plan view of a conveyor system 114 according to one embodiment. The conveyor system 114 includes one or more conveyor elements 160. The conveyor system is configured to transport substrates 110 at a speed of from about 300 m / s to about 600 m / s. As described above with respect to Figure 1AAs described, the first conveyor device 115, the intermediate conveyor device 117, and the second conveyor device 119 include one or more conveyor elements 160. The substrate 110 is positioned on the conveyor element 160 during movement. Figure 1B In the example depicted in FIG, substrate 110 is a rectangular substrate suitable for manufacturing solar cells. Substrate 110 has a width D sub , the width is arranged in an orientation perpendicular to the direction of travel of the substrate 110 along the conveyor element 160. Therefore, the length of the substrate 110 has an orientation aligned in the direction of travel of the substrate 110 along the conveyor element 160. The substrate (or wafer) 110 may have, but is not limited to, a substrate width D of about 175 mm to about 250 mm. sub , such as about 175 mm to about 225 mm. The length of the substrate 110 may be about the same as the width D sub Same, width D sub Longer or shorter. The width D of the rectangular substrate 110 sub Orthogonal to the direction of travel along the first conveyor device 115.

[0053] As shown, conveyor element 160 includes a first conveyor belt 161 having a first width W1 and a second conveyor belt 162 having a second width W2, one or more sensors 164, and a conveyor base 163. Second conveyor belt 162 is parallel to first conveyor belt 161. Conveyor element 160 is configured to transport substrates 110 along a centerline 165 of the conveyor element. First width W1 and second width W2 are between about 8 mm and about 20 mm, such as between about 8 mm and about 10 mm or between about 10 mm and about 20 mm. First conveyor belt 161 and second conveyor belt 162 are supported by conveyor base 163 and are movable relative to the conveyor base.

[0054] The two conveyor belts 161, 162 are separated by a belt span D BB Spaced apart. With separation span D BB Defined between the center of the first belt 161 and the center of the second belt 162. According to one example, the belt separation span D BB From about 90 mm to about 150 mm. The first belt span D 1B Defined between the center of the first belt 161 and the centerline 165. The second belt span D 2B Defined between the center of the second belt 162 and the centerline 165. According to one example, the first belt span D 1B and the second belt span D 2BRange from about 45 mm to about 75 mm. If multiple conveyor devices are combined, the two belts 161, 162 can be shared by multiple conveyor elements 160. The two belts 161, 162 are typically driven by a common motor (not shown) to control the movement of the substrate 110 downstream along the conveyor elements 160.

[0055] According to one example, one or more sensors 164 are disposed between the two belts 161, 162. The one or more sensors 164 are supported by the conveyor base 163. The one or more sensors 164 can be configured to monitor one or more characteristics of the substrate 110. For example, the one or more sensors 164 can be configured to monitor the resistivity and / or thickness of the substrate 110. The one or more sensors 164 can be part of one or more metrology stations 116. (That is, the one or more sensors are not part of the metrology station 116).

[0056] The conveyor element 160 is configured to support the substrate 110 such that a portion of the substrate 110 O extends beyond each of the two belts 161, 162. For example, the portion 110 O has a width of about 10 mm to about 20 mm. Having a portion 110 that extends beyond the conveyor element 160 O allows easier imaging of the sides of the substrate 110 to find defects.

[0057] It has been found that transporting a substrate 110 with a large width D using a conventional transport system sub causes large vibrations at the edges of the substrate 110. The undesirable vibrations at the edges of the substrate 110 make it difficult to image the edges of the substrate to find notches or other defects. Additionally, if the two belts 161, 162 are spaced too far apart, the center 110C of the substrate 110 may sag, which may cause a portion of the substrate to be out of focus for an imaging sensor or other sensors. The conveyor element 160 as disclosed herein enables better transport of the substrate 110 during imaging than a conventional transport system. In other words, the conveyor element 160 causes the substrate 110 to have reduced edge vibrations and reduces the sagging of the center 110C of the substrate and the bulging of the corners of the substrate.

[0058] Figure 1C is a flowchart of a method 166 for transporting a rectangular substrate (e.g., substrate 110) according to one embodiment. Although the method operations are described in conjunction with Figures 1A to 1C it will be understood by those skilled in the art that the method 166 can be performed using other equipment. The method 166 can be stored as a computer-readable medium containing instructions in or accessible to the controller 190, the instructions which, when executed by a processor of the controller 190, cause the inspection system 100 to perform the method 166.

[0059] Method 166 begins with operation 167, in which a rectangular substrate is transported by a conveyor system (e.g., conveyor system 114). The rectangular substrate has a width of from about 175 mm to about 250 mm, which width is orthogonal to the direction of travel of a first conveyor device (e.g., first conveyor device 115) along the conveyor system. The rectangular substrate is transported on the conveyor system at a speed of from about 300 m / s to about 600 m / s. The speed of the rectangular substrate is selected to coordinate with the belt span in order to minimize vibration of the edges of substrate 110. The high speeds disclosed herein increase the number of wafers per hour inspected (WPH), thereby reducing the user's cost of ownership.

[0060] At operation 168, the rectangular substrate is transported to a rotary sorting system (e.g., rotary sorting system 120). Method 166 may also include transporting substrates to and from metrology station 116, transporting substrates to and from substrate spinner 180, transporting substrates to and from front end 102, and transporting substrates to and from conveyor inspection system 170.

[0061] As described above, an inspection system is provided. The inspection system is configured to analyze notches, cracks, and other defects in substrates. The inspection system includes a conveyor device, and the conveyor device includes one or more conveyor elements. The conveyor elements are configured to transport solar cell substrates having a large width. The conveyor elements include belts for transporting substrates.

[0062] The spacing of the belts reduces vibration of the substrate edges. Reducing vibration of the substrate edges allows for more accurate imaging of the substrate edges. If the substrate edges are accurately imaged, false positives or false negatives in side imaging of the substrate are reduced, thereby reducing waste of substrates that are inaccurately identified as damaged.

[0063] Figure 2 FIG. shows a top plan view of a rotary sorting system 120 according to one embodiment. The rotary sorting system 120 is configured to place substrates 110 in various bins according to the metrology values of each substrate. As shown, the rotary sorting system 120 includes a rotatable support 122. The rotatable support 122 is configured to rotate the substrate 110 about a rotation axis R. The rotatable support 122 can be a rotating disk, a circular support, or any other shape for efficiently sorting substrates 110.

[0064] As shown, the rotatable support 122 includes a plurality of arms 124. Each arm 124 is configured to rotate a given substrate 110 about the sorting unit 106. Each arm 124 has a first end 126 and a second end 128. The first end 126 of each arm 124 is coupled to the rotatable support 122 via a suitable connection such as, by way of example, a welded connection, a pinned connection, a fastening connection, etc. The second end 128 of each arm 124 extends radially outward relative to the axis of rotation R. In one embodiment, the rotatable support 122 includes twelve arms 124. It is contemplated that any number of arms 124 may be included, such as ten or more arms 124, such as fourteen or sixteen arms.

[0065] At least one gripper 130 is coupled to the second end 128 of each arm 124. Each gripper 130 may be disposed on the bottom side or end of each of the arms 124 such that each gripper 130 grasps the substrate 110 once the inspected substrate 110 reaches the sorting unit 106. Each gripper 130 may be a suction gripper, a claw gripper, a magnetic gripper, a picker, or other suitable gripper. In one embodiment, each gripper 130 is a Bernoulli picker.

[0066] One or more sorting bins 140 are disposed radially outside the axis of rotation R. In one embodiment, ten sorting bins 140 are utilized. It is contemplated that any number of sorting bins 140 may be utilized, such as six, eight, or twelve sorting bins 140. When the plurality of arms 124 are rotated by the rotatable support 122, the sorting bins 140 may be positioned directly below the path taken by the grippers 130. According to one embodiment, the rotary sorting system 120 rotates about the axis of rotation R in a stepwise manner such that the rotary sorting system 120 stops when each substrate 110 enters the sorting unit 106 to grip (i.e., pick up) the substrate 110 from the conveyor system 114. The sorting bins 140 are positioned to receive the substrate 110 from the rotary sorting system 120. The substrate 110 is sorted into the sorting bins 140 in response to one or more substrate characteristics determined during one or more of the inspection processes performed at the metrology stations 116A - 116E. The rotary sorting system 120 positions the substrate 110 above the sorting bin 140 assigned to receive substrates having at least one predetermined substrate characteristic. The substrate 110 is then released from the respective gripper 130 into the appropriate sorting bin 140. The sorting bins 140 store the sorted substrate 110 when the gripper 130 releases the substrate.

[0067] The sorting bins 140 can each be individually removed from the sorting unit 106. Each sorting bin 140 can be removably connected to the sorting unit 106, such as by a separately removable drawer or container, a slide-out container, or a pull-out drawer or container for the above connection. Each sorting bin 140 can be accessible from outside the sorting unit 106, such that each sorting bin 140 can be removed from the sorting unit 106 without entering the sorting unit 106. By pulling out the sorting bin 140 from the sorting unit 106, a full sorting bin 140 can be removed from the sorting unit 106. When the sorting unit 106 sorts the substrates 110, each sorting bin 140 can be removable from the sorting unit 106. Thus, even if a particular sorting bin 140 is full or has been removed, the sorting of the substrates 110 can continue. Therefore, each sorting bin 140 can be emptied or replaced while sorting is being performed.

[0068] In addition, the controller 190 can count the number of substrates 110 in each sorting bin 140 by using a counter (not shown). Thus, when a particular sorting bin 140 is full or not in place, the sorting unit 106 skips the full or removed sorting bin 140 until the full or removed sorting bin 140 is emptied or replaced. Once an empty sorting bin 140 is replaced within the sorting unit 106, the counter is reset for that particular sorting bin 140. The counter can be automatically reset each time a sorting bin 140 is replaced or emptied. An operator can empty or replace a full sorting bin 140. Thus, the sorting unit 106 can continue to rotate the substrates 110 until the assigned sorting bin 140 is available. If no sorting bin 140 is available, the sorting unit 106 can alarm the operator and continue to rotate the substrates 110 until a suitable sorting bin 140 becomes available. Once the controller 190 determines that a particular sorting bin 140 is approaching or has reached its capacity, the controller 190 can alarm the operator by sounding an alarm and / or displaying an alarm.

[0069] Although not shown, it is contemplated that additional sorting bins 140 can be located within the sorting unit 106 to receive substrates 110 that are inadvertently missed from sorting, thereby preventing damage to such substrates. Although ten sorting bins 140 are shown, it is contemplated that more or fewer than ten sorting bins 140 can be included within the sorting unit 106, such as six, eight, eighteen, or twenty-four sorting bins 140. In addition, a rejection bin 144 can be located within the sorting unit 106 to capture substrates 110 that have been rejected by one or more of the metrology stations 116A - 116E of the modular inspection unit 104. Thus, the rotary sorting system 120 can transfer unwanted substrates to the rejection bin 144.

[0070] The rotary sorting system 120 may also include a yield analysis server 146 that is accessible by one or more access panels. The yield analysis server 146 is coupled to the front end 102 and one or more of the metrology stations 116A - 116E, and is adapted to receive, collect, analyze, store, and / or report data regarding each substrate 110 passing through the front end or the metrology stations received from the front end 102 and the one or more metrology stations 116A - 116E.

[0071] The rotatable support 122 is coupled to a rotary actuator (not shown) such as a cylinder or a stepper motor. The rotary actuator rotates the rotatable support 122, such as in an indexing manner. At each indexing step of the rotatable support 122, a new substrate 110 is received onto the rotary sorting system 120 via each gripper 130 from the modular inspection unit 104 via the conveyor system 114. Additionally, as further discussed below, the rotatable support 122 may index each of the plurality of arms 124 over a respective sorting bin 140 and / or over the reject bin 144 such that the substrate 110 is released into the sorting bin 140 or the reject bin 144. By continuous movement or indexing steps, the substrate 110 can be continuously removed from the conveyor system 114, thereby immediately freeing up space on the conveyor system 114 for the next substrate 110. In this way, the rotational movement allows each gripper 130 to dock with each sorting bin 140 such that the substrate held by the gripper 130 will be released into one of the sorting bins 140 before the gripper 130 rotates back to receive another substrate 110. The rotary sorting system 120 will continue to move until all substrates 110 have been sorted.

[0072] In some embodiments, the rotary sorting system 120 picks up substrates 110 transferred from the modular inspection unit 104 via the conveyor system 114 every 2 / 3 of a second. In such embodiments, the rotary sorting system 120 sorts at least 5,400 substrates per hour, which is a significant improvement over conventional sorting systems.

[0073] Figure 3A is a partial top plan view of an inspection system 100 according to one embodiment, illustrating the conveyor inspection system 170. Figure 3BFIG. 0 is a side plan view of inspection system 100 according to one embodiment, showing conveyor inspection system 170 in a first orientation. Conveyor inspection system 170 is configured to transport substrate 110 to a destination, where the destination depends on the quality of the substrate. As shown, conveyor inspection system 170 includes intermediate conveyor device 117, movable conveyor actuator 209, exit conveyor 203, image capture device 250, one or more illumination sources 260, fast conveyor 210, and waste bin 240. Conveyor actuator 209 and any other actuator described herein can be a motor, a hydraulic actuator, a pneumatic actuator, or other motion control mechanism.

[0074] As shown, intermediate conveyor device 117 includes entry conveyor 201, movable conveyor 202, and movable conveyor actuator 209. Intermediate conveyor device 117 and thus entry conveyor 201, movable conveyor 202, and exit conveyor 203 can include any means configured to carry the substrate along intermediate conveyor device 117. For example, intermediate conveyor device 117 can include a belt, rollers, a mesh, or one or more of other means / machineries suitable for transporting the substrate through intermediate conveyor device 117. Intermediate conveyor device 117 can further include a carrier or tray to carry the substrate, where the carrier or tray is moved by a drive mechanism. Each of entry conveyor 201, movable conveyor 202, and movable conveyor actuator 209 can be driven individually.

[0075] Image capture device 250 can be a camera, a charge-coupled device (CCD), or other means suitable for determining that the substrate is not suitable for further transport to modular inspection unit 104. Substrate 110 can be transported from front end 102, across entry conveyor 201, movable conveyor 202, exit conveyor 203, and into modular inspection unit 104, whereby entry conveyor 201, movable conveyor 202, and exit conveyor 203 can be considered components of intermediate conveyor device 117.

[0076] As Figure 3A shown, the translation means 270, 272, 274 (e.g., the belts of the conveyors or equivalents) of entry conveyor 201, movable conveyor 202, and exit conveyor 203 are generally but not necessarily aligned in a linear direction. The translation means 272 of movable conveyor 202 are generally closer together than the translation means 276 of fast conveyor 210. The translation means 276 of fast conveyor 210 are generally narrower than the width of the substrate, such that when movable conveyor 202 moves between the translation means 276 of fast conveyor 210, the substrate is lifted from movable conveyor 202 and placed on fast conveyor 210, as further described below.

[0077] Figure 3B The figure shows the path of an exemplary substrate 110 in a first orientation through a conveyor inspection system 170. The substrate is placed on an infeed conveyor 201 by a transfer robot 108 from a cassette (or other source). During the transfer of the substrate 110 across the infeed conveyor 201, the portion of the infeed conveyor 201 through which the substrate travels is irradiated by one or more illumination sources 260 (the irradiation is illustrated by a light beam 261). The portion of the infeed conveyor 201 that is irradiated by one or more illumination sources 260 is also within the field of view of an image acquisition device 250. While irradiating the substrate 110, the image acquisition device 250 obtains an image of at least the edge of the substrate. Generally, while the substrate is moving across the infeed conveyor 201, the infeed conveyor 201 obtains an image of the substrate 110.

[0078] A controller 190 obtains an image or image data from the image acquisition device 250. The controller 190 analyzes the image to determine whether the substrate 110 is undesirable or suitable for further transfer to a modular inspection unit 104. Examples of undesirable substrates include substrates having visible damage (such as cracking, nicks, or damaged corners and / or edges). In another example, an undesirable substrate includes two substrates stacked on top of each other, i.e., a double substrate. Standard image analysis algorithms or other suitable algorithms can be used to analyze the image to determine whether the substrate 110 is undesirable or suitable for further inspection. In one example, the profile of the substrate 110 is measured, and the area of the substrate is calculated based on the profile. If the area of the substrate 110 is less than a certain area limit, the substrate is considered damaged and thus undesirable. If the area of the substrate 110 is greater than a certain area limit, the substrate is considered a double substrate and thus undesirable.

[0079] The controller 190 causes the conveyor inspection system 170 to direct the substrate from the movable conveyor 202 to the outfeed conveyor 203 in response to the controller 190 determining that the substrate is desirable, or to direct the substrate to the fast conveyor 210 in response to the controller 190 determining that the substrate is undesirable. Return reference Figure 3B In an example, when it is determined that the substrate 110 is suitable, the suitable substrate 110 is then transferred across the movable conveyor 202 and the outfeed conveyor 203 to the modular inspection unit 104.

[0080] The movable conveyor 202 is configured to convey the substrate 110 from the incoming conveyor 201 to the outgoing conveyor 203. The movable conveyor 202 is configured to convey the substrate 110 at the same speed as the incoming conveyor 201 system and the outgoing conveyor 203. Although the movable conveyor 202 is illustrated as being coplanar with the incoming conveyor 201 and the outgoing conveyor 203, any suitable arrangement of the incoming conveyor, the movable conveyor, and the outgoing conveyor is contemplated in the first orientation of the conveyor inspection system 170. For example, the incoming conveyor 201 and / or the outgoing conveyor 203 may be set at an angle to the movable conveyor 202, provided that the movable conveyor 202 is configured to move the substrate from the incoming conveyor to the outgoing conveyor when the conveyor inspection system 170 is in the first orientation.

[0081] Figure 3C FIG. shows a side plan view of the conveyor inspection system 170 in a second orientation according to one embodiment. The path of the undesired substrate 111 (e.g., a fractured substrate determined using the image capture device 250) through the conveyor inspection system 170 in the second orientation is shown. In response to the substrate 111 being determined to be undesired, the movable conveyor actuator 209 rotates the movable conveyor 202 in a direction away from the outgoing conveyor 203. In other words, the movable conveyor actuator 209 rotates the movable conveyor 202 from a position coplanar with the outgoing conveyor 203 to a position below the outgoing conveyor 203 and forming an acute angle with the outgoing conveyor.

[0082] The fast conveyor 210 is set at an acute angle to the movable conveyor 202 and below the movable conveyor (when in the first orientation) and at an acute angle to the outgoing conveyor 203. The fast conveyor 210 may include any suitable means configured to carry the substrate across the fast conveyor 210. For example, the fast conveyor 210 may include one or more of a belt, rollers, a mesh, or other device(s) / mechanism suitable for transporting the substrate through the fast conveyor 210. The fast conveyor 210 may further include a carrier or tray for carrying the substrate, wherein the carrier or tray is moved by a drive mechanism. The fast conveyor 210 may be driven independently.

[0083] The fast conveyor 210 includes a plurality of translation devices 211 (e.g., the belt of the fast conveyor or the like). The fast conveyor 210 is also disposed below the outgoing conveyor 203. According to one embodiment, the transition device 211 includes a plurality of lower belts, and two of the lower belts are on opposite sides of the movable conveyor 202. As Figure 3A, the transition device 211 is shown outside the movable conveyor 202. However, the transition device 211 can be located anywhere, as long as the transition device 211 is positioned to remove substrates when the conveyor inspection system 170 is oriented in the second orientation. According to one embodiment, the transition device 211 is located inside the movable conveyor 202, and the movable conveyor includes an aperture (not shown) that allows the transition device 211 to pass through the aperture when the movable conveyor 202 is moved to the second orientation. The transition device 211 can be moved from above the movable conveyor 202 to an appropriate position so that the transition device 211 is positioned to move substrates in the second orientation.

[0084] The movable conveyor 202 rotates so that the undesired substrate 111 disposed in the movable conveyor 202 is aligned with the translation device (276, such as Figure 3A ) contact, thereby transferring the substrates 111 from the movable conveyor 202 to the express conveyor 210. The express conveyor 210 then transfers the undesired substrates 111 to a waste bin 240 disposed below the entry conveyor. Thus, the undesired substrates 111 are removed from the inspection system 100 before suitable substrates can be moved to the modular inspection units 104. Removing the undesired substrates 111 from the inspection system 100 reduces jamming of the modular inspection units 104, thereby reducing cost of ownership.

[0085] According to one embodiment, the movable conveyor 202 is configured to operate at a first speed and the fast conveyor 210 is configured to operate at a second speed, and the second speed is greater than the first speed. The relative first and second speeds are determined at least in part by the size of the substrate 110, the rate at which the substrate moves across the conveyor inspection system 170, and the distance between substrates during operation of the conveyor inspection system 170. Generally speaking, the relative first and second speeds are selected to allow a substrate to be transferred from the movable conveyor 202 to the fast conveyor 210 and to allow the movable conveyor 202 to return to the first orientation to receive the next substrate traveling across the conveyor inspection system 170 without causing any interruption to the rate at which the substrates travel through the inspection system 100.

[0086] The movable conveyor 202 is generally movable between a first orientation (e.g., a first position) configured to transfer substrates from the entry conveyor 201 to the exit conveyor 203 and a second orientation (e.g., a second position) configured to transfer substrates from the entry conveyor 201 to the express conveyor 210. Figure 3B and Figure 3CAs shown, the movable conveyor 202 is pivotable at a first end 230 disposed closer to the inlet conveyor 201. For example, the first end 230 is attached to a shaft (not shown) that allows the movable conveyor 202 to pivot about the axis of the shaft, thereby allowing the angular orientation of the movable conveyor 202 to be controllably selected. However, in other embodiments, the movable conveyor 202 can pivot about an axis offset from the axis of the movable conveyor 202 such that the first end 230 moves as the movable conveyor 202 rotates. In any case, the movable conveyor 202 rotates and / or moves away from the outlet conveyor 203 to allow the substrate to be transferred from the movable conveyor 202 to the fast conveyor 210.

[0087] The controller 190 can include or access a non-transitory computer-readable medium storing instructions. The non-transitory computer-readable medium storing the instructions can be executed by a processor (e.g., the CPU of the controller 190). The instructions can be executed by the processor to determine whether the substrate 110 is defective based on an image, and when a defective substrate is detected on the movable conveyor 202, in response to the substrate being defective, cause the movable conveyor 202 to move (e.g., rotate) from a first orientation (e.g., Figure 3B the orientation shown in ) to a second orientation (e.g., Figure 3C the orientation shown in ), which causes the defective substrate to be transferred to the fast conveyor 210 and carried by the fast conveyor to the waste bin 240, and return the movable conveyor 202 to the first orientation before the next substrate arrives on the movable conveyor.

[0088] Although the movable conveyor 202 in the second position is illustrated as being generally coplanar with the fast conveyor 210, any arrangement of the movable conveyor and the fast conveyor in the second position of the conveyor inspection system 170 is contemplated. For example, the fast conveyor 210 can be disposed at an angle to the movable conveyor 202 as long as the movable conveyor 202 is configured to move the substrate from the inlet conveyor to the fast conveyor when the conveyor inspection system 170 is in the second position.

[0089] Figure 4 is a flowchart of a method 400 for sorting substrates 110 according to one embodiment. Although the method operations are described in connection with Figure 3B 、 Figure 3C and Figure 4 it will be understood by those skilled in the art that the method 400 can be performed using other equipment. The method 400 can be stored as a computer-readable medium containing instructions in or accessible to the controller 190, the instructions when executed by the processor of the controller 190 cause the inspection system 100 to perform the method 400.

[0090] Method 400 begins with operation 410, where substrate 110 is transported by an infeed conveyor, such as infeed conveyor 201 of conveyor inspection system 170.

[0091] At operation 420, an image of substrate 110 is taken by an image acquisition device 250, such as a camera. In one example, while operation 420 is being performed, the infeed conveyor continues to move substrate 110.

[0092] At operation 430, the image is analyzed to determine whether substrate 110 is undesirable or suitable for further inspection. A controller, such as controller 190, determines whether substrate 110 is undesirable or suitable based on predefined criteria, such as by comparing the acquired image with a reference image obtained from an image library or derived from an algorithm. Operation 430 includes determining a measured area of substrate 110 from the image of the substrate and comparing the measured area with a predefined range of acceptable values to determine whether substrate 110 is undesirable or suitable for further inspection.

[0093] At operation 440, substrate 110 is transported to a destination in response to determining whether the substrate is suitable or undesirable. If it is determined at operation 430 that substrate 110 is suitable for further inspection, the substrate is transferred across movable conveyor 202 and, when in the first position, across outfeed conveyor 203 to modular inspection unit 104, as Figure 3B shown. If it is determined at operation 430 that the substrate is undesirable, movable conveyor actuator 209 moves movable conveyor 202 (with the undesirable substrate disposed thereon) in a direction away from outfeed conveyor 203 to a second position, where the substrate is transferred from movable conveyor 202 to fast conveyor 210. In one example, movable conveyor 202 rotates in a direction away from outfeed conveyor 203 and between fast conveyors 210. Fast conveyor 210 is arranged at an angle to and below movable conveyor 202. Movable conveyor 202 rotates such that undesirable substrate 111 contacts fast conveyor 210, thereby lifting the substrate from movable conveyor 202 and onto fast conveyor 210. Fast conveyor 210 moves the substrate at a speed greater than the speed at which the substrate is moved across movable conveyor 202 and then transfers undesirable substrate 111 to waste bin 240 disposed below the infeed conveyor. Once the substrate moving on fast conveyor 210 has left movable conveyor 202, movable conveyor 202 returns to the first orientation, in which movable conveyor 202 can receive the next substrate from infeed conveyor 201.

[0094] As described above, a conveyor inspection system and a method of sorting substrates are provided. The conveyor inspection system includes a movable conveyor and a fast conveyor. The movable conveyor is configured to transfer undesired substrates to the fast conveyor. The method includes: determining that it is not desired for the substrate to enter the modular inspection unit; in response to determining that it is not desired for the substrate to enter the modular inspection unit, transferring the substrate to the fast conveyor; and transporting the substrate on the fast conveyor.

[0095] The conveyor inspection system and the method remove substrates from the test system upon first entry into the test system, which reduces the time wasted analyzing undesired substrates that will be discarded. Additionally, removing the undesired substrates reduces clogging of the test system, thereby reducing the cost of ownership.

[0096] Figure 5A FIG. shows a side plan view of a substrate rotator 180 in a first orientation according to one embodiment. Figure 5B FIG. shows a top plan view of a substrate rotator 180 in a first orientation according to one embodiment. As shown, the substrate rotator 180 includes a rotating device 554 and a support device 550. The support device 550 supports the rotating device 554 as the rotating device rotates.

[0097] The substrate rotator 180 includes a body 501 having a first gripper 510 and a second gripper 512, the first and second grippers being coupled to the body in a manner that allows the grippers 510, 512 to rotate in response to rotation of the body 501. Synchronous relative movement of the grippers 510, 512 and the body 501 can be achieved by using one or more motors, actuators, linkages, belts, gears, combinations of the foregoing, or other suitable devices. In the example described below, synchronous rotation of the grippers 510, 512 in response to simultaneous rotation of the body 501 can be achieved using a single actuator.

[0098] The support device 550 is configured to support the rotating device 554. As shown, the support device 550 includes a machine base 587, a pillar 586, a support rod 585, an overhead support 583, a main actuator 502, a main belt 582, a shaft 557, a vacuum supply tube 581, a vacuum supply source 556, and a rotary union 555. The overhead support 583 is coupled to the pillar 586 by the support rod 585. The pillar 586 is supported by the machine base 587.

[0099] The shaft 557 is connected to the main actuator 502 by the main belt 582. The shaft 557 is held by one or more bearings 575 that allow the shaft to rotate about the central axis of the shaft 557. The main actuator 502 rotates the shaft 557 via the main belt 582. The shaft 557 is disposed in a passage (not shown) in the elevated support 583, and the shaft 557 rotates while in the passage, while the elevated support 583 does not rotate. The shaft 557 extends through the elevated support 583 and into the underlying body 501. The shaft 557 is surrounded by a tube 584. The tube 584 is separated from the shaft 557 by one or more bearings 575.

[0100] A vacuum supply source 556 is coupled to the first gripper 510 and the second gripper 512 via a vacuum supply tube 581. The vacuum provided by the vacuum supply source 556 allows the first gripper 510 and the second gripper 512 to pick up a substrate, as described in further detail below. The vacuum supply tube 581 passes through the shaft 557 and into the body 501 and into the first gripper 510 and the second gripper 512. In embodiments where the first gripper 510 and the second gripper 512 do not require vacuum to operate, the vacuum supply source 556 and the vacuum supply tube 581 can be eliminated.

[0101] The rotation device 554 is configured to rotate one or more substrates. In Figure 5A the example shown, the rotation device 554 includes a body 501, a first gear 511, a main gear 590, a first gripper 510, a second gear 513, a second gripper 512, a belt 534, a first minor gear 531, and a second minor gear 532. The main actuator 502 is configured to rotate the shaft 557 and thus the body 501 about an axis 592. The axis 592 is generally perpendicular to the conveyor system 114 and the plane of the substrate moving on the conveyor system 114. The axis 592 is positioned to pass through the center of the body 501.

[0102] The body actuator 502 can rotate the body 501 in both clockwise and counterclockwise directions. The body actuator 502 is configured to rotate the body 501 between a first position and a second position by approximately 180 degrees. The body actuator 502 is configured to rotate the body 501 in an alternating clockwise and counterclockwise sequence such that when the body 501 is in the first position or the second position, the grippers 510, 512 attached to the body 501 are located above the conveyor system 114 and linearly aligned with the conveyor system 114.

[0103] The body 501 is elongated and has a first end 551 and a second end 552. A first gripper 510 is coupled to the first end 551 such that the first gripper 510 can rotate about a first gripper axis 594. Similarly, a second gripper 512 is coupled to the second end 552 such that the second gripper 512 can rotate about a second gripper axis 596. The axes 594, 596 are generally parallel to the axis 592 such that when the body 501 is rotated by the body actuator 502, the grippers 510, 512 and their axes 594, 596 rotate laterally about the axis 592. A first auxiliary gear 531 and a second auxiliary gear 532 are disposed on opposite sides of the body actuator 502 and the axis 592. A main gear 590 is rotatably coupled to the body 501 and an intermediate gear is about the shaft 557. The main gear 590 interfaces with the first auxiliary gear 531 and the second auxiliary gear 532 using a belt 534. When the body 501 is rotated by the body actuator 502, the main gear 590 remains stationary relative to the body 501 while the grippers 510, 512 and the auxiliary gears 531, 532 freely rotate laterally with the body 501 about the shaft 557 on the axis 592. When the body actuator 502 rotates the body 501, the relative lateral rotation of the gears 531, 532 about the main gear 590 causes the belt 534 to be driven (i.e., advanced) by the main gear 590.

[0104] A first gear 511 is disposed at the first end 551 of the body 501. The first auxiliary gear 531 is connected to the first gear 511 by a belt 534. The first gear 511 is coupled to the first gripper 510 such that when the first gear 511 rotates about the axis 594 in a first direction, the first gripper 510 also rotates about the axis 594 in the first direction. A second gear 513 is disposed at the second end 552 of the body 501. The second auxiliary gear 532 is connected to the second gear 513 by a belt 534. The second gear 513 is coupled to the second gripper 512 such that when the second gear rotates about the axis 596 in a first rotation, the second gripper 512 also rotates about the axis 596 in the first direction. Since the belt 534 is coupled to both of the gears 531, 532, both of the grippers 510, 512 rotate simultaneously at a predetermined ratio in response to the grippers 510, 512 being rotated laterally about the axis 592 by the body 501 simultaneously.

[0105] In one example, the belt 534 is routed such that when the body 501 rotates in one direction, both of the grippers 510, 512 rotate in opposite directions. In another embodiment, the belt 534 is routed such that when the body 501 rotates in one direction, both of the grippers 510, 512 rotate in the same direction, such as by twisting the belt 534 between one of the gears 531, 532 and the main gear 590. Alternatively, the relative direction of the simultaneous rotation of the grippers 510, 512 can be selected by using multiple belts, gears, or other mechanisms. In an embodiment where the grippers 510, 512 rotate simultaneously in opposite directions, the substrate rotator 180 is configured such that one gripper rotates 180 degrees more than the other gripper, such as rotating 90 degrees as compared to 270 degrees in response to a 180-degree rotation of the body 501. In an embodiment where the grippers 510, 512 rotate simultaneously in the same direction, the substrate rotator 180 is configured such that one gripper rotates the same amount as the other gripper, such as both of the grippers 510, 512 rotating 90 degrees in response to a 180-degree rotation of the body 501.

[0106] In one example, the body 501 rotates in a first direction to rotate the substrate held in the first gripper 510 to a position closer to the next station 116, while the second gripper 512 without a substrate moves to a position for receiving the next substrate advancing downstream along the conveyor system 114. When the first gripper rotates in the first direction, the substrate rotates such that one of the trailing or leading edges of the substrate (as oriented at the previous station 116). Thereafter, the second gripper 512 picks up the next substrate advancing downstream along the conveyor system 114, and when the body 501 rotates the second gripper 512 and the substrate closer to the next station 116 in a second direction, the substrate rotates to the same orientation as the previous substrate was placed back on the conveyor system 114 by the first gripper 510. When the body 501 rotates in opposite first and second directions, the twisting of the electrical and fluid conduits within the substrate rotator 180 is substantially eliminated.

[0107] The first gripper 510 and the second gripper 512 are configured to grip the first substrate and the second substrate, respectively. Each gripper 510, 512 can be a suction gripper, an electrostatic chuck (ESC), a claw gripper, a magnetic gripper, a picker, or other suitable gripper. In one embodiment, each gripper 510, 512 is a Bernoulli picker.

[0108] In FigureIn the example depicted, the gear ratio between the first gear 511 and the main gear 590 is 2:1, such that the first gripper 510 rotates at half the first angle by which the body actuator rotates. For example, if the body actuator 502 rotates the body 501 by approximately 180 degrees, the first gripper 510 rotates by approximately 90 degrees. The gear ratio between the main gear 590 and the second gear 513 is 1:1.5, such that the second gripper 512 rotates at three-halves of the first angle by which the body 501 rotates. For example, if the body actuator 502 rotates the body 501 by approximately 180 degrees, the second gripper 512 rotates by approximately 270 degrees.

[0109] Although ​ the first gripper 510 and the second gripper 512 illustrated in are coupled to the body actuator 502 by belts 534 and gears 511, 513, 531, 532, 590, other coupling means may also be used. For example, the gears 511, 513 are directly coupled to the main gear 590. In other examples, linkages may couple the body actuator 502 to the first gripper 510 and the second gripper 512. In another example, separate actuators (not shown) are independently coupled to the first gripper 510 and the second gripper 512 and rotate the first gripper 510 and the second gripper 512 independent of the body actuator 502.

[0110] ​ is a flowchart of a method 600 for performing metrology on a substrate according to one embodiment. Although the method operations are described in conjunction with ​ and ​ those skilled in the art will understand that any system configured to perform the method operations in any order falls within the scope of the embodiments described herein. The method 600 may be stored as computer-readable media containing instructions on or accessible to the controller 190, the instructions which, when executed by a processor of the controller 190, cause the inspection system 100 to perform the method 600.

[0111] The method 600 begins at operation 610, where metrology is performed on a first set of sides of a substrate, such as the first set of sides 520FS of the first substrate 520. The metrology may be performed at the metrology station 116D. The metrology station 116D includes a CSI, and as the substrate passes through the metrology station 116D, the CSI images the first set of sides 520FS of the first substrate 520 to inspect for notches, cracks, or other defects on the first set of sides of the substrate. According to one embodiment, the first set of sides 520FS of the first substrate 520 is parallel to the direction in which the substrate moves downstream along the conveyor system 114.

[0112] At operation 615, metrology is performed on a first set of side faces 521FS of the second substrate 521. The metrology can be performed at metrology station 116D. The metrology station 116D includes a CSI, and as the second substrate passes through the metrology station 116D, the CSI images the first set of side faces 521FS of the second substrate 521 to inspect for notches, cracks, or other defects on the first set of side faces of the substrate. According to one embodiment, the first set of side faces 521FS of the second substrate 521 is parallel to the direction in which the substrate moves downstream along the conveyor system 114.

[0113] At operation 620, the first substrate 520 is rotated by a first angle such that a second set of side faces 520SS of the first substrate is in the same orientation as a first set of side faces 520FS before the first substrate was rotated. The substrate 520 can be picked up from an upstream location of the conveyor system 114. According to one embodiment, the first substrate 520 is square, and the first angle is about 90 degrees. According to one embodiment, the conveyor system 114 can be stopped and the first substrate 520 can be rotated while stationary. The conveyor system 114 can move while the first substrate 520 is being rotated, but this requires placing the first substrate 520 further downstream on the conveyor system 114 when the rotation is complete. If the first substrate 520 is not placed further downstream on the conveyor system 114, the substrate 520 may be undesirably placed on another substrate.

[0114] In some embodiments, operation 620 is performed by a substrate rotator 180. ​ and ​ The substrate rotator 180 is illustrated in a first orientation, where the substrate rotator grasps the first substrate 520 with a first gripper 510. According to one embodiment, the first substrate 520 is rotated about the centerline of the first substrate by about 90 degrees while being laterally rotated 180 degrees in a first direction. According to one embodiment, the first substrate 520 is rotated about the centerline of the first substrate by about 270 degrees while being laterally rotated 180 degrees in a first direction. In either case, the first substrate 520 is rotated such that the second set of side faces 520SS is set in the same facing direction as the first set of side faces 520FS was located. In embodiments where the first gripper 510 and the second gripper 512 are Bernoulli pickers, the first substrate 520 is picked up by the first gripper 510 without the first gripper moving in the z direction (i.e., away from the surface of the conveyor system 114 and / or away from the top surface of the first substrate 520). The Bernoulli picker uses vacuum to attract and grasp the first substrate 520, and thus movement of the first gripper 510 in the z direction is not necessary. According to one embodiment, the second substrate 521 continues to move downstream along the conveyor system 114, and thus the picked-up first substrate 520 partially overlaps the second substrate 521 before the substrate rotator 180 rotates.

[0115] ​ FIG. Side plan view of substrate rotator 180 in a second orientation according to one embodiment. ​ FIG. Top plan view of substrate rotator 180 in a second orientation according to one embodiment. In this embodiment, the second orientation illustrates that the substrate rotator 180 is rotated approximately 180° relative to the first orientation. If the gear ratio between the first gear 511 and the gear of the main actuator 502 is 2:1, then the first gripper 510 also rotates approximately 90 degrees. The substrate 520 is co-rotated a total of 180 degrees + 90 degrees = 270 degrees relative to the original orientation of the substrate. Thus, the first set of sides 520FS is perpendicular to the direction in which the substrate 520 moves downstream along the conveyor system 114. Also, the second set of sides 520SS is parallel to the direction in which the substrate 521 moves downstream along the conveyor system 114. Finally, the length of the body 501 and the rotational speed of the main actuator 502 can be selected such that the substrate 520 is placed at the correct distance downstream of the conveyor system 114 to maintain a sufficient substrate spacing. The substrate 520 continues to move downstream along the conveyor system 114 to the metering station 116E.

[0116] Additionally, ​ and ​ FIG. illustrates the second gripper 512 gripping the second substrate 521, where the first set of sides 521FS of the second substrate is parallel to the direction in which the substrate moves downstream along the conveyor system 114. The second substrate 521 can be picked up from an upstream position of the conveyor system 114. The second gripper 512 also allows the second substrate 521 to rotate, as further described below. Gripping the second substrate 521 increases the efficiency of the method by doubling the number of substrates that are reoriented within the same time frame. According to one embodiment, the second substrate 521 is rotated approximately -270 degrees about the centerline of the second substrate while being laterally rotated 180 degrees in a direction opposite to the first direction. According to one embodiment, the second substrate 521 is rotated approximately -90 degrees about the centerline of the second substrate while being laterally rotated 180 degrees in a direction opposite to the first direction. In either case, the second substrate 521 is rotated such that the second set of sides 521SS is set in the same facing direction as the first set of sides 521FS was located. In an embodiment where the first gripper 510 and the second gripper 512 are Bernoulli pickers, the second substrate 521 is picked up by the second gripper 512 without the second gripper moving in the z-direction (i.e., away from the surface of the conveyor system 114). The Bernoulli picker uses vacuum to attract and grip the second substrate 521, and thus movement of the second gripper 512 in the z-direction is not necessary. Additionally, when the vacuum in the Bernoulli picker is reduced, the first substrate 520 falls onto the conveyor device 114 without the Bernoulli picker moving in the z-direction.

[0117] At operation 625, the second substrate 521 is rotated by a second angle such that a second set of sides 521SS of the second substrate is in the same orientation as a first set of sides 521FS of the second substrate prior to rotation of the second substrate. According to one embodiment, the second substrate 521 is square and the second angle is approximately 270°. According to one embodiment, the conveyor system 114 can be stopped and the second substrate 521 can be rotated while stationary. The conveyor system 114 can move while the second substrate 521 is being rotated, but this requires that the second substrate 521 be placed further downstream of the conveyor system 114 when rotation is complete. If the second substrate 521 is not placed further downstream of the conveyor system 114, the second substrate 521 may be undesirably placed on top of another substrate.

[0118] ​ A side plan view of the substrate rotator 180 in a third orientation according to one embodiment is shown. ​ A top plan view of the substrate rotator 180 in a third orientation according to one embodiment is shown. In the present embodiment, the third direction describes the substrate rotator 180 rotated approximately -180 degrees relative to the second orientation. Thus, the third orientation of the substrate rotator 180 is similar to the first orientation.

[0119] If the gear ratio between the second gear 513 and the gear of the body actuator 502 is 3:2, the second gripper 512 also rotates approximately -270 degrees. The second substrate 521 co-rotates -180 degrees - 270 degrees = -90 degrees = 270 degrees relative to the original orientation of the second substrate. Thus, the second set of sides 521FS is perpendicular to the direction in which the substrate 521 moves downstream along the conveyor system 114. Moreover, the second set of sides 521SS is parallel to the direction in which the substrate 521 moves downstream along the conveyor system 114. Finally, the first substrate 520 and the second substrate 521 are in the same orientation, i.e., rotated 270 degrees relative to the original orientation of the first substrate 520 and the second substrate 521.

[0120] At operation 630, metrology is performed on a second set of sides of the substrate, such as the second set of sides 520SS of the first substrate 520. The metrology can be performed at the metrology station 116E. The metrology station 116E includes a CSI and, as the substrate passes through the metrology station 116E, the CSI images the second set of sides 520SS of the first substrate 5 for inspection of notches, cracks, or other defects on the first set of sides of the substrate. According to one embodiment, the second set of sides 520SS of the first substrate 520 is parallel to the direction in which the substrate moves downstream along the conveyor system 114. Thus, method 600 results in metrology of multiple sets of sides 520FS, 520SS of the first substrate 520.

[0121] At operation 635, metrology is performed on the second set of side faces 521SS of the second substrate 521. The metrology can be performed at metrology station 116E. The metrology station 116E includes a CSI, and as the substrate passes through the metrology station 116E, the CSI images the second set of side faces 521SS of the second substrate 521 to inspect for notches, cracks, or other defects on the second set of side faces of the substrate. According to one embodiment, the second set of side faces 521SS of the second substrate 521 is parallel to the direction in which the substrate moves downstream along the conveyor system 114. Thus, method 600 results in the metrology of multiple sets of side faces 521FS, 521SS of the second substrate 521.

[0122] In one example, the body 501 rotates in a first direction in one step and the body rotates in the opposite direction in a second step. ​ Schematic illustration of the body 501 rotating in a first direction according to one embodiment. ​ Schematic illustration of ​ between ​ the same motion that exists. The body 501 rotates in a first direction (shown by arrow 701). The first gripper rotates in the same direction as the first direction of the body 501 (shown by arrow 702). The second gripper rotates in the direction opposite to the first direction of the body 501 (shown by arrow 703). For example, the body 501 rotates 180 degrees in the first direction, the first gripper rotates 90 degrees in the first direction, and the second gripper rotates -270 degrees in the first direction.

[0123] ​ Schematic illustration of the body 501 rotating in a second direction according to one embodiment. ​ Schematic illustration of ​ between ​ the same motion that exists. The body 501 rotates in a second direction (shown by arrow 701). The second direction is opposite to the first direction. The first gripper rotates in the same direction as the second direction of the body 501 (shown by arrow 702). The second gripper rotates in the direction opposite to the second direction of the body 501 (shown by arrow 703). For example, the body 501 rotates 180 degrees in the second direction, the first gripper rotates 90 degrees in the second direction, and the second gripper rotates -270 degrees in the second direction. Thus, the body 501 and the first gripper and the second gripper end up in the same orientation as they started. ​ , ​ The motion of the body 501 illustrated in can be achieved using an actuator (e.g., the main actuator 502) that rotates only 180 degrees instead of rotating the entire 360 degrees.

[0124] In another example, the body 501 rotates in a first direction in one step, and the body rotates in the same direction in a second step. ​ FIG. is a schematic diagram of a body 501 rotating in a first direction according to an embodiment. The body 501 rotates in a first direction (shown by arrow 701). The first gripper rotates in the same direction as the first direction of the body 501 (shown by arrow 702). The second gripper rotates in the same direction as the first direction of the body 501 (shown by arrow 703). For example, the body 501 rotates 180 degrees in the first direction, the first gripper rotates 90 degrees in the first direction, and the second gripper rotates 270 degrees in the first direction.

[0125] ​ FIG. is a schematic diagram of a body 501 rotating in a second direction according to an embodiment. The body 501 rotates in a second direction (shown by arrow 701). The first gripper rotates in the same direction as the first direction of the body 501 (shown by arrow 702). The second gripper rotates in the same direction as the first direction of the body 501 (shown by arrow 703). For example, the body 501 rotates 180 degrees in the second direction, the first gripper rotates 90 degrees in the second direction, and the second gripper rotates 270 degrees in the second direction. Thus, the body 501 and the first gripper and the second gripper terminate in the same orientation as they started. ​ , ​ The movement of the body 501 illustrated in FIG. can use an actuator that rotates in one direction (e.g., the main actuator 502), and does not have to rotate backward.

[0126] As described above, a substrate rotator, a substrate edge metrology system, and a method of rotating a substrate are provided. The substrate rotator includes a body having a first end and a second end, a body actuator coupled between the first end and the second end and configured to rotate the body, a first gripper coupled to the first end, and a second gripper coupled to the second end. The substrate rotator is configured to rotate one or more substrates while further moving the substrate along a conveyor. The substrate edge metrology system includes two metrology systems and a substrate rotator. The substrate edge metrology system measures side notches or other defects on all sides of the substrate by rotating the substrate between metrology stations. The method includes performing metrology on a first set of sides of a first substrate, rotating the first substrate a first angle, and performing metrology on a second set of sides of the first substrate. The method allows measurement of side notches or other defects on all sides of the substrate.

[0127] The substrate is analyzed by a substrate edge metrology system for side notches or other defects on all sides of the substrate, thereby allowing easier identification and removal of undesirable substrates. Different from conventional metrology substrates, the substrate spinner allows measurement of all sides of the substrate without having to stop the conveyor.

[0128] Those skilled in the art will appreciate that the foregoing examples are illustrative and not restrictive. It is contemplated that all permutations, additions, equivalents, and improvements of the foregoing examples will be apparent to those skilled in the art upon reading the specification and studying the drawings and are included within the true spirit and scope of the present disclosure. Accordingly, it is contemplated that the appended claims include all such modifications, permutations, and equivalents that fall within the true spirit and scope of these teachings.

Claims

1. A system for inspecting a rectangular substrate having a width between 175 mm and 250 mm, comprising: One or more metrology stations configured to inspect the rectangular substrate; And A conveyor system configured to transport the rectangular substrate while the one or more metrology stations inspect the rectangular substrate, the conveyor system comprising: A conveyor inspection system comprising: A movable conveyor configured to rotate from a first orientation to a second orientation, wherein the movable conveyor receives the rectangular substrate in the first orientation; and A fast conveyor which is arranged at an angle to the movable conveyor and below the movable conveyor when in the first orientation, the fast conveyor being configured to lift the rectangular substrate from the movable conveyor while the movable conveyor is rotating to the second orientation; A first conveyor device; and A second conveyor device, each of the conveyor inspection system, the first conveyor device and the second conveyor device comprising one or more conveyor elements, the one or more conveyor elements comprising: A first conveyor belt and a second conveyor belt parallel to the first conveyor belt, wherein the first conveyor belt and the second conveyor belt are configured to transport the rectangular substrate having a width between 175 mm and 250 mm in the travel direction when the width of the rectangular substrate is orthogonal to the travel direction, and the first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm.

2. The system according to claim 1, wherein the one or more conveyor elements further comprise a plurality of sensors disposed between the first conveyor belt and the second conveyor belt.

3. The system according to claim 2, wherein the one or more metrology stations further comprise the plurality of sensors.

4. The system according to claim 2, wherein the center of the first conveyor belt is set at a first belt span from the center line of the conveyor element, the center of the second conveyor belt is set at a second belt span from the center line, and the widths of the first conveyor belt and the second conveyor belt are 8 mm to 10 mm.

5. The system according to claim 1, the conveyor inspection system further comprising: An inlet conveyor, the movable conveyor being positioned to receive the rectangular substrate from the inlet conveyor; An image acquisition device positioned to obtain an image of the rectangular substrate disposed on the inlet conveyor; And An illumination source, wherein the illumination source is configured to emit illumination light onto the inlet conveyor within the field of view of the image acquisition device, wherein the conveyor inspection system is configured to transport the rectangular substrate from the first conveyor device to the second conveyor device.

6. The system according to claim 5, wherein the conveyor inspection system further includes an exit conveyor positioned to receive the rectangular substrate from the movable conveyor in the first orientation.

7. The system according to claim 6, wherein the conveyor inspection system further includes a quick conveyor actuator configured to rotate the movable conveyor relative to the exit conveyor by a first angle.

8. The system according to claim 7, wherein the quick conveyor is positioned to move the rectangular substrate to a waste bin.

9. The system according to claim 1, further comprising: a substrate rotator, the substrate rotator including: a body having a first end and a second end; a body actuator coupled between the first end and the second end to the body and configured to rotate the body; a first gripper coupled to the first end, the first gripper configured to rotate a first rotation in response to a 180-degree rotation of the body, the first gripper configured to rotate a first substrate held in the first gripper by the first rotation; and a second gripper coupled to the second end, the second gripper configured to rotate a second rotation in response to a 180-degree rotation of the body, the second gripper configured to rotate a second substrate held by the second gripper by the second rotation, wherein the absolute value of the second rotation is greater than the first rotation; wherein the substrate rotator is configured to transport the rectangular substrate from a first portion of the second conveyor device to a second portion of the second conveyor device.

10. The system according to claim 9, wherein the first gripper and the second gripper are configured to rotate at different speeds.

11. The system according to claim 9, further comprising: a shaft coupling the body to the body actuator; a tube surrounding the shaft; a main gear surrounding the tube; a belt coupled to the main gear; a first gear coupled to the belt; and a second gear coupled to the belt.

12. The system according to claim 11, wherein the main gear, the first gear, and the second gear have different radii from each other.

13. The system according to claim 12, wherein the gear ratio between the first gear and the main gear is 2:1, and the gear ratio between the main gear and the second gear is 1:1.

5.

14. A system for inspecting a rectangular substrate having a width between 175 mm and 250 mm, comprising: a front end; one or more metrology stations configured to inspect the rectangular substrate; and a conveyor system configured to transport the rectangular substrate while the one or more metrology stations inspect the rectangular substrate, the conveyor system including: a conveyor inspection system, the conveyor inspection system including: A movable conveyor configured to rotate from a first orientation to a second orientation, wherein the movable conveyor receives the rectangular substrate in the first orientation; and A fast conveyor, which is arranged at an angle to and below the movable conveyor when in the first orientation, and is configured to lift the rectangular substrate from the movable conveyor when the movable conveyor is rotating to the second orientation; A first conveyor device; and A second conveyor device, each of the conveyor inspection system, the first conveyor device and the second conveyor device includes one or more conveyor elements, and the one or more conveyor elements include: A first conveyor belt and a second conveyor belt parallel to the first conveyor belt, wherein the first conveyor belt and the second conveyor belt are configured to transport the rectangular substrate with a width between 175 mm and 250 mm in the traveling direction when the width of the rectangular substrate is orthogonal to the traveling direction, the first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm, and the front end is configured to transport the rectangular substrate to the conveyor system.

15. The system according to claim 14, wherein each of the one or more conveyor elements further includes a plurality of sensors disposed between the first conveyor belt and the second conveyor belt.

16. The system according to claim 15, wherein the one or more metering stations further include the plurality of sensors.

17. The system according to claim 15, wherein the center of the first conveyor belt is set at a first belt span from the center line of the conveyor element, the center of the second conveyor belt is set at a second belt span from the center line, and the widths of the first conveyor belt and the second conveyor belt are 8 mm to 10 mm.

18. A method of transporting a rectangular substrate with a width between 175 mm and 250 mm, the method comprising: Transporting the rectangular substrate on a conveyor system, the conveyor system including: A conveyor inspection system, the conveyor inspection system including: A movable conveyor configured to rotate from a first orientation to a second orientation, wherein the movable conveyor receives the rectangular substrate in the first orientation; and A fast conveyor, which is arranged at an angle to and below the movable conveyor when in the first orientation, and is configured to lift the rectangular substrate from the movable conveyor when the movable conveyor is rotating to the second orientation; A first conveyor device; and A second conveyor device, each of the first conveyor device and the second conveyor device includes one or more conveyor elements, and the one or more conveyor elements include: A first conveyor belt and a second conveyor belt parallel to the first conveyor belt, wherein the first conveyor belt and the second conveyor belt are configured to transport the rectangular substrate having a width between 175 mm and 250 mm in the traveling direction when the width of the substrate is orthogonal to the traveling direction, the first conveyor belt and the second conveyor belt are spaced apart by a belt separation span between 90 mm and 150 mm, and the rectangular substrate is transported on the conveyor system at a speed between 300 m / s and 600 m / s; and transporting the rectangular substrate to a rotary sorting system.

19. The method according to claim 18, wherein each of the one or more conveyor elements further comprises a plurality of sensors disposed between the first conveyor belt and the second conveyor belt.

20. The method according to claim 18, wherein the center of the first conveyor belt is set at a first belt span from the center line of the conveyor element, the center of the second conveyor belt is set at a second belt span from the center line, and the widths of the first conveyor belt and the second conveyor belt are from 8 mm to 10 mm.

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