BACKGROUND Semiconductor device fabrication is a process used to create integrated circuits that are present in everyday electronic devices. The fabrication process is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer composed of a semiconducting material. During fabrication, the edge of the wafer may become warped, damaged, or otherwise unsuitable for use with electronic circuits. Hence, the edge of the wafer may be trimmed during fabrication.
BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
FIGS. 1A, 1B, and 1C illustrate cross-sections of intermediate stages in the processing of workpieces including a trimming step, in accordance with some embodiments.
FIGS. 2A, 2B, and 2C illustrate cross-sections of intermediate stages in the processing of workpieces including a trimming step, in accordance with some embodiments.
FIG. 3 illustrates a schematic plan view of a trimming tool, in accordance with some embodiments.
FIG. 4 illustrates a schematic perspective view of a trimming tool, in accordance with some embodiments.
FIG. 5 shows schematic perspective views of a blade attached to the end of an arm of a blade holder, in accordance with some embodiments.
FIGS. 6A, 6B, 6C, 6D, and 6E, intermediate steps of a trimming process utilizing a trimming tool are shown, in accordance with some embodiments.
FIG. 7 illustrates process flow for a trimming process, in accordance with some embodiments.
FIGS. 8A and 8B illustrate a process for dressing a blade with a dressing board, in accordance with some embodiments.
FIGS. 9A and 9B illustrate dressing boards, in accordance with some embodiments.
FIGS. 10A, 10B, and 10C illustrate a sensor for a blade and example blade measurements, in accordance with some embodiments.
FIG. 11 illustrates a schematic plan view of a trimming tool, in accordance with some embodiments.
FIG. 12 illustrates a schematic cross-sectional view of a portion of a trimming tool, in accordance with some embodiments.
DETAILED DESCRIPTION The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
A trimming tool for trimming wafers is described herein, according to various embodiments. The trimming tool described herein includes a blade holder configured to hold and operate multiple trimming blades such that multiple workpieces (e.g., wafers) can be trimmed by different blades on the blade holder. Additionally, the blade holder is configured to rotate such that some blades can be “dressed” (e.g., cleaned using one or more dressing boards) while other blades are used to trim workpieces. In this manner, the rate at which workpieces are trimmed may be increased while still allowing blades to be dressed as needed. This can reduce processing time and improve efficiency. The blade holder may also include sensors that monitor blade position or blade conditions, which can allow for more efficient and cost-effective blade dressing.
FIGS. 1A through 1C and FIGS. 2A through 2C illustrate cross-sections of intermediate stages in the processing of workpieces including a trimming step, in accordance with some embodiments. The processes shown in FIGS. 1A-1C and 2A-2C are illustrative examples, and any other suitable processes including trimming step may be used with the embodiments of the present disclosure. In FIGS. 1A-1C and 2A-2C, a first wafer 10 is bonded to a second wafer 20 to form a workpiece 50. In some cases, the workpiece 50 may also be referred to as a “wafer,” a “reconstituted wafer,” a “bonded structure,” a “stacked wafer structure,” or the like. Edge portions of the workpiece 50 are then removed in a trimming process, which may be performed using embodiments described herein. In some cases, trimming a workpiece 50 may reduce warping, cracking, or debonding.
In FIG. 1A, the first wafer 10 is bonded or otherwise attached to the second wafer 20 to form the workpiece 50. In some embodiments, the first wafer 10 and/or the second wafer 20 may be a semiconductor wafer such as a silicon bulk wafer or a gallium arsenide wafer. In some embodiments, the first wafer 10 and/or the second wafer comprises, for example, silicon, strained silicon, silicon alloy, silicon carbide, silicon-germanium, silicon-germanium carbide, germanium, a germanium alloy, germanium-arsenic, indium-arsenic, group III-V semiconductors, a combination thereof, or the like. In some embodiments, the first wafer 10 and/or the second wafer 20 is a buried oxide (BOX) wafer, a device wafer, an interposer, an organic core substrate, a combination thereof, or the like. The first wafer 10 and the second wafer 20 may have similar or different materials or dimensions. The first wafer 10 may be bonded to the second wafer 20 using direct bonding (e.g., dielectric-to-dielectric bonding and/or metal-to-metal bonding), using an adhesive, or using another suitable technique. In some cases, the second wafer 20 may be considered a “carrier,” a “carrier substrate,” or a “carrier wafer.”
In FIG. 1B, the workpiece 50 is trimmed, in accordance with some embodiments. During the trimming process, a region 45 around the edge of the workpiece 50 is removed. For example, the trimmed region 45 may be removed vertically downward from the first wafer 10 toward the second wafer 20. The trimmed region 45 may extend partially or fully through the first wafer 10 and may extend partially or fully through the second wafer 20. For example, the trimmed region 45 shown in FIG. 1B extends fully through the first wafer 10 and partially through the second wafer 20. In FIG. 1C, the first wafer 10 is thinned using a suitable process, such as a chemical mechanical polish (CMP) process, a grinding process, an etching process, a combination thereof, or the like. The thinning process reduces the thickness of the first wafer 10.
The process shown in FIGS. 2A-2C is similar to the process shown in FIGS. 1A-1C, except that the workpiece 50 is thinned before the workpiece 50 is trimmed. FIG. 2A shows a workpiece similar to that of FIG. 1A. In FIG. 2B, the workpiece 50 is thinned to reduce the thickness of the first wafer 10. In FIG. 2C, a trimming process is performed to remove a region 45 around the edge of the workpiece 50, similar to the trimming process described for FIG. 1C.
FIGS. 3 and 4 illustrate a trimming tool 100, in accordance with some embodiments. FIG. 3 illustrates a schematic plan view of the trimming tool 100, and FIG. 4 illustrates a schematic perspective view of the trimming tool 100. Some features or details may be not be shown for clarity reasons. The trimming tool 100 may be used to trim one or more workpieces 50, which may be similar to the workpieces 50 described above for FIGS. 1A-2C, though other workpieces 50 are possible. In some embodiments, the trimming tool 100 comprises a blade holder 110 configured to hold and operate multiple trimming blades 120. In this manner, the blade holder 110 may be considered a “multi-blade holder.” The blade holder 110 comprises multiple arms 112 that extend from a hub 111 at a central axis 113, with a blade 120 attached to the end of each arm 112. For example, the blade holder 110 shown in FIGS. 3-4 has four arms 112A-D with four corresponding blades 120A-D. In other embodiments, the blade holder 110 has a different number of arms 112, such as two, three, or more than four arms 112. In some embodiments, the blade holder 110 is operable to rotate around the central axis 113 to reposition the arms 112 and the corresponding blades 120. FIG. 3 also shows robotic arms 60 that may be used to transfer workpieces 50 into or out of the trimming tool 100, in accordance with some embodiments.
FIG. 5 shows schematic perspective views of a blade 120 attached to the end of an arm 112, in accordance with some embodiments. In some embodiments, the blade 120 is attached to an actuator 122 within the arm 112 by a spindle 124. The actuator 122 may comprise a motor, a hydraulic actuator, a pneumatic actuator, a robotic arm, another type of actuator or mechanism, a combination thereof, or the like. In some embodiments, the actuator 122 may be configured to rotate the blade 120 (e.g., clockwise and/or counterclockwise, such as during trimming or dressing) or laterally translate (e.g., extend or retract) the blade 120. As an illustrative example, FIG. 5 shows the blade 120 in two different lateral positions after translation by the actuator 122. In some embodiments, the actuator 122 may laterally translate the blade 120 within a range from about 1 mm to about 50 mm, but other ranges of translation are possible. The actuator 122 may translate the blade 120 to suitably align the blade 120 with a workpiece 50 during a trimming process or to suitably align the blade 120 with a dressing board 130 during a dressing process, for example. In some embodiments, the arm 112, the actuator 122, and/or the spindle 124 may comprise a spring or damper (not shown) that reduces vibrations of the blade 120 during operation.
In some embodiments, a blade 120 attached to an arm 112 may have a diameter in the range of about 10 mm to about 300 mm, though other diameters are possible. The blade 120 may be formed of any suitable materials or have any suitable characteristics. For example, the blade 120 may comprise a bonding material of ceramic, resin, rubber, chlorine oxide (e.g., oxychloride), nickel, the like, or a combination thereof. The blade 120 may have a grit size in the range of #100 to #7000, though other grit sizes are possible. In some embodiments, the blade 120 may have grit comprising diamond, cubic boron nitride (CBN), silicon carbide, aluminum oxide, zirconia alumina, zirconium dioxide, ceramic, garnet, the like, or a combination thereof. In some embodiments, the blade 120 may have a grit coating comprising nickel, nickel chrome, nickel aluminum, aluminum bronze, aluminum oxide, chrome oxide, zirconium oxide, chrome carbide nickel chrome, nickel graphite, aluminum, copper, molybdenum, tungsten carbide cobalt, titanium oxide, the like, or a combination thereof. Other materials are possible.
The various blades 120 attached to the arms 112 of a blade holder 110 may have similar or different characteristics. For example, returning to FIGS. 3 and 4, the blades 120A and 120C respectively attached to arms 112A and 112C have a relatively course grit, and the blades 120B and 120D respectively attached to arms 112B and 112D have a relatively fine grit. Other combinations of blades and blade characteristics are possible. In some embodiments, a trimming process for a workpiece 50 may comprise trimming the workpiece 50 with a course blade 120 (e.g., blade 120A or 120C) and then trimming the workpiece 50 with a fine blade 120 (e.g., blade 120B or 120D). Accordingly, blades 120A and 120C may be referred to as “course blades” herein, and blades 120B and 120D may be referred to as “fine blades” herein. The multi-armed blade holder 110 described herein allows for a single workpiece 50 to be trimmed with multiple blades 120 during a trimming process.
Still referring to FIGS. 3 and 4, the trimming tool 100 comprises a trimming station 102 that supports and rotates workpieces 50 during a trimming process, in accordance with some embodiments. The trimming station 102 comprises a first platen 104A and a second platen 104B that are each configured to hold a workpiece 50. For example, FIGS. 3-4 show the first platen 104A holding a first workpiece 50A and the second platen 104B holding a second workpiece 50B. A trimming station 102 may comprise a different number of platens 104 in other embodiments. A platen 104 may secure a workpiece 50 using, e.g. vacuum suction or another suitable technique, and may rotate the workpiece 50 (e.g., clockwise or counterclockwise) during a trimming process, in some embodiments.
The trimming tool 100 also comprises one or more dressing boards 130, in accordance with some embodiments. The dressing boards 130 are used to clean, reshape, and refresh blades 120 after performing a trimming process. The dressing boards 130 are supported by a dressing station 132, and in some embodiments, each dressing board 130 may have its own dressing station 132. For example, FIGS. 3-4 show a first dressing board 130A on a first dressing station 132A and a second dressing board 130B on a second dressing station 132B. In other embodiments, both the first dressing board 130A and the second dressing board 130B may be supported by the same dressing station 132. In some embodiments, a dressing board 130 may be rotated, translated, or positioned by the dressing station 132.
In some embodiments in which the trimming tool 100 has two or more dressing boards 130, the various dressing boards 130 may have similar or different characteristics. For example, referring to FIGS. 3-4, the first dressing board 130A may be suited for a blade 120 having relatively course grit (e.g., blade 120A or 120C), and the second dressing board 130B may be suited for a blade 120 having relatively fine grit (e.g., blade 120B or 120D). In this manner, a dressing board 130 may be referred to as a “course dressing board” or a “fine dressing board” herein. Other combinations of dressing boards and dressing board characteristics are possible.
In some embodiments, the trimming tool 100 comprises a sensor arm 106 that measures characteristics of a workpiece 50 during or after performing a trimming process. The sensor arm 106 may monitor, detect, or measure characteristics of a trimmed region (e.g., trimmed region 45 of FIGS. 1B-1C or 2B-2C) of a workpiece 50, such as depth, width, roughness, location, or the like. The sensor arm 106 may comprise one or more sensors, which may be laser-based sensors, optical sensors (e.g., OCD sensors, CCD sensors, or the like) or other types of sensors. In some embodiments, the sensor arm 106 may be operable to rotate or translate between a first position to measure a first workpiece 50 (e.g., first workpiece 50A in FIG. 3) and a second position to measure a second workpiece 50 (e.g., second workpiece 50B in FIG. 3). In other embodiments, each platen 104 has an associated sensor arm 106.
A trimming tool comprising a multi-blade holder may have a different configuration than the trimming tool 100 shown in FIGS. 3-4. As another non-limiting example, FIG. 11 illustrates a trimming tool 300, in accordance with some embodiments. The trimming tool 300 has a blade holder 110 configured to hold six blades 120A-F, which may be similar blades or blades of different types. The trimming tool 300 also includes five platens (not separately shown) to hold five workpieces 50A-E and includes one dressing board 130 on a dressing station 132. The trimming tool 300 is configured such that the five workpieces 50A-E may be trimmed simultaneously by five of the blades 120 (e.g., blades 120A-E) while the remaining blade 120 (e.g., blades 120F) is dressed at the dressing board 130. The blade holder 110 may rotate in order to align different blades 120A-F with different platens or with the dressing board 130. Another number or arrangement of blades 120, workpieces 50, dressing boards 130, or other features is possible in other embodiments.
Turning to FIGS. 6A through 6E, intermediate steps of an example trimming process utilizing the trimming tool 100 are shown, in accordance with some embodiments. The trimming process shown in FIGS. 6A-6E is an illustrative example, and other trimming processes with different steps or different sequences of steps may be used in other embodiments. Some of the actions described below for a step may be performed sequentially, and some of the actions described below for a step may be performed simultaneously. Some of the actions described below for a step may be performed in a different order than described. Using a suitable trimming process such as that described for FIGS. 6A-6E, the trimming tool 100 as described herein allows for the efficient trimming of workpieces 50 including the dressing of blades 120 with an improved “wafer-per-hour” rate. Additionally, the trimming process described in FIGS. 6A-6E allow for each workpiece 50 to be trimmed with a course blade and then a fine blade, which can improve the smoothness and reproducibility of the trimmed region and reduce the risk of cracking or warping of the workpiece 50.
In FIG. 6A, the blade holder 110 is in a position such that a workpiece 50 on the first platen 104A can be trimmed using the fine blade 120B and a workpiece 50 on the second platen 104B can be trimmed using the course blade 120A. In some cases, the position of the blade holder 110 in FIG. 6A may be considered an “initial position” or a “first position.” The workpiece 50A on the first platen 104A is trimmed using the fine blade 120B and then removed from the first platen 104A (e.g., by a robotic arm 60). The workpiece 50A may be removed from the first platen 104A and transferred to a cleaning station or the like, for example. The workpiece 50B is loaded onto the second platen 104B (e.g., by a robotic arm 60) and then trimmed using the course blade 120A.
Still referring to FIG. 6A, the blade holder 110 is also in a position such that the course blade 120C may be dressed using the course dressing board 130A and the fine blade 120D may be dressed using the fine dressing board 130B. In some embodiments, the blades 120C-D may be dressed while the workpieces 50A-B are trimmed by the blades 120A-B. The dressing of the blades 120C and/or 120D when the blade holder 110 is in the first position is optional, and one, both, or neither of the blades 120C-D may be dressed. In some embodiments, the condition of a blade 120 may be monitored or measured, and whether or not the blade 120 is dressed may be determined from the condition of the blade 120. In some cases, a blade 120 may be dressed after trimming a predetermined number of workpieces 50 since the previous dressing of the blade 120.
In FIG. 6B, the blade holder 110 is rotated to a position such that a workpiece 50 on the first platen 104A can be trimmed using the course blade 120C and a workpiece 50 on the second platen 104B can be trimmed using the fine blade 120B. For example, the blade holder 110 may be rotated 90° around the central axis 113 as shown in FIG. 6B, or may be rotated another appropriate angle. In some cases, the position of the blade holder 110 in FIG. 6B may be considered a “second position.” A workpiece 50C is loaded onto the first platen 104A (e.g., by a robotic arm 60) and then trimmed using the course blade 120C. The workpiece 50B on the second platen 104B is trimmed using the fine blade 120B and then removed from the second platen 104B (e.g., by a robotic arm 60). Still referring to FIG. 6B, the blade holder 110 is also in a position such that the course blade 120A is aligned with the fine dressing board 130B and the fine blade 120D is aligned with the course dressing board 130A. Thus, in some embodiments, no blades 120 are dressed when the blade holder 110 is in the second position.
In FIG. 6C, the blade holder 110 is rotated to a position such that a workpiece 50 on the first platen 104A can be trimmed using the fine blade 120D and a workpiece 50 on the second platen 104B can be trimmed using the course blade 120C. For example, the blade holder 110 may be rotated a further 90° around the central axis 113 as shown in FIG. 6C, or may be rotated another appropriate angle. In some cases, the position of the blade holder 110 in FIG. 6C may be considered a “third position.” The workpiece 50C on the first platen 104A is trimmed using the fine blade 120D and then removed from the first platen 104A (e.g., by a robotic arm 60). A workpiece 50D is loaded onto the second platen 104B (e.g., by a robotic arm 60) and then trimmed using the course blade 120C. Still referring to FIG. 6C, the blade holder 110 is also in a position such that the course blade 120A is aligned with the course dressing board 130A and the fine blade 120B is aligned with the fine dressing board 130B. In this manner, the blade 120A and/or the blade 120B may optionally be dressed when the blade holder 110 is in the third position.
In FIG. 6D, the blade holder 110 is rotated to a position such that a workpiece 50 on the first platen 104A can be trimmed using the course blade 120A and a workpiece 50 on the second platen 104B can be trimmed using the fine blade 120D. For example, the blade holder 110 may be rotated a further 90° around the central axis 113 as shown in FIG. 6D, or may be rotated another appropriate angle. In some cases, the position of the blade holder 110 in FIG. 6D may be considered a “fourth position.” A workpiece 50E is loaded onto the first platen 104A (e.g., by a robotic arm 60) and then trimmed using the course blade 120A. The workpiece 50D on the second platen 104B is trimmed using the fine blade 120D and then removed from the second platen 104B (e.g., by a robotic arm 60). Still referring to FIG. 6D, the blade holder 110 is also in a position such that the course blade 120C is aligned with the fine dressing board 130B and the fine blade 120B is aligned with the course dressing board 130A. Thus, in some embodiments, no blades 120 are dressed when the blade holder 110 is in the fourth position.
In FIG. 6E, the blade holder 110 is rotated back to the first position. For example, the blade holder 110 may be rotated 270° around the central axis 113 in a reverse direction, as shown in FIG. 6D, or may be rotated another appropriate angle. The workpiece 50E on the first platen 104A is trimmed using the fine blade 120B and then removed from the first platen 104A (e.g., by a robotic arm 60). A workpiece 50F is loaded onto the second platen 104B (e.g., by a robotic arm 60) and then trimmed using the course blade 120A. Similar to FIG. 6A, the blade 120C and/or the blade 120D may optionally be dressed when the blade holder 110 is in the first position. In this manner, the steps described in FIGS. 6A through 6E may be repeated to efficiently trim workpieces 50 and dress blades 120.
FIG. 7 illustrates process flow 200 for a trimming process, in accordance with some embodiments. The trimming process described by the process flow 200 of FIG. 7 is similar to the trimming process described previously in FIGS. 6A-6E. At step 202, a workpiece on a first platen is trimmed using a fine blade and then removed from the first platen. At step 202, a workpiece is also loaded on a second platen and then trimmed using a course blade. Additionally, one or more blades may optionally be trimmed at step 202. Step 202 is similar to the intermediate step shown in FIG. 6A or the intermediate step shown in FIG. 6E.
At step 204, the blade holder is rotated to a second position. At step 206, a workpiece is loaded on the first platen and then trimmed using a course blade. At step 206, the workpiece on the second platen is also trimmed using the fine blade and then removed from the second platen. Steps 204 and 206 are similar to the intermediate step shown in FIG. 6B.
At step 208, the blade holder is rotated to a third position. At step 210, the workpiece on the first platen is trimmed using a fine blade and then removed from the first platen. At step 210, a workpiece is also loaded on the second platen and then trimmed using the course blade. Additionally, one or more blades may optionally be trimmed at step 210. Steps 208 and 210 are similar to the intermediate step shown in FIG. 6C.
At step 212, the blade holder is rotated to a fourth position. At step 214, a workpiece is loaded on the first platen and then trimmed using a course blade. At step 214, the workpiece on the second platen is also trimmed using the fine blade and then removed from the second platen. Steps 212 and 214 are similar to the intermediate step shown in FIG. 6D.
At step 216, the blade holder is rotated back to the first position, which is similar to the intermediate step shown in FIG. 6E. The trimming process may then continue from step 202 to trim additional workpieces.
FIGS. 8A and 8B illustrate the repositioning of a dressing board 130, in accordance with some embodiments. In some embodiments, a dressing board 130 may be repositioned to provide an unused surface for the dressing of a blade 120. The dressing board 130 may be repositioned, for example, by an actuator within the dressing station 132 that rotates or translates the dressing board 130. An illustrative example is shown in the schematic plan views of FIGS. 8A and 8B, in which a dressing board 130 is rotated after the dressing of a blade 120. FIG. 8A illustrates the dressing board 130 after dressing a blade 120, and FIG. 8B illustrates the dressing board 130 prior to a subsequent dressing of a blade 120. In FIG. 8A, the dressing of the blade 120 results in a used region 131A of the dressing board 130 due to the dressing process. In FIG. 8B, the dressing board 130 is rotated by a suitable angle A1 to move the used region 131A away from the location under a blade 120 during dressing and move an unused region 131B into the location under a blade 120 during dressing. In this manner, the dressing board 130 may be rotated as needed to provide an unused region for the dressing of a blade 120, which can improve the quality of the dressing of the blade 120 and thus improve the quality of the trimming using that blade 120.
In some embodiments, a dressing board 130 may have different regions that are suitable for blades 120 having different grit sizes. In this manner, a single dressing board 130 may be used for dressing different types of blades 120. FIGS. 9A and 9B show two illustrative examples of dressing boards 130 having different grit regions 133 that are suitable for blades 120 having different grit sizes. For example, FIG. 9A shows a dressing board 130 having grit regions 133A-C corresponding to different grit sizes, and FIG. 9B shows a dressing board having grit regions 133A-B corresponding to different grit sizes. In FIG. 9A, the different grit regions 133A-C are arranged in concentric rings or annuli. In FIG. 9B, the different grit regions 133A-B are arranged as adjacent sections (e.g., two halves) of the dressing board 130. These are illustrative examples, and other dressing boards 130 having other numbers, arrangements, shapes, or combinations of grit regions 133 are possible.
In some embodiments, a dressing board 130 may be rotated to align an unused region of the dressing board 130 and/or to align a different grit region 133 with a blade 120 prior to the dressing of the blade 120. By providing dressing boards 130 with different grit regions 133, blades 120 of different types can be dressed without using a separate dressing board 130 for each type of blade 120. In some embodiments, a blade 120 may be positioned over a particular region of a dressing board 130, such as over an unused region or a region corresponding to a different grit. For example, the position of the blade 120 may be controlled by adjusting the rotation angle of the blade holder 110 or by adjusting the protrusion of the blade 120 from the arm 112 using the actuator 122 (see FIG. 5). The adjustment of the blade 120 position may be combined with any of the dressing boards 130 described herein. In this manner, the size of the trimming tool 100 may be reduced, the time needed for dressing when multiple blades 120 are used may be reduced, and trimming quality may be improved.
In some embodiments, the blade holder 110 may include one or more sensors that allow for monitoring or measuring of blade 120 characteristics. An illustrative example is shown in the schematic cross-section of FIG. 10A, which shows a portion of a blade holder 110 including a portion of the hub 111 and an arm 112, in accordance with some embodiments. As shown in FIG. 10A, one or more sensors 140 may be located in the hub 111, though the sensors 140 may have different locations in other embodiments. In some embodiments, each blade 120 attached to the blade holder 110 may have a corresponding sensor 140 or set of sensors 140 located in the blade holder 110. For example, a blade holder 110 that holds four blades 120 may have four sets of sensors 140. The sensors 140 may be configured to measure characteristics of the corresponding blade 120 such as position, roughness, diameter, uniformity, planarity, or other characteristics. One sensor 140 may measure more than one characteristic of a blade 120, in some cases. In some embodiments, the sensors 140 may measure blade 120 characteristics as the blade 120 spins, which may be during trimming, during dressing, or when the blade 120 is not in use. For example, in some embodiments, a sensor 140 may measure the characteristics of a blade 120 when the blade 120 is positioned over an unsuitable dressing board 130, such as blades 120A or 120D in FIG. 6B. In some embodiments, the sensors 140 may be laser-based sensors, optical sensors, or other types of sensors. The example sensor 140 shown in FIG. 10A is a laser-based sensor. In some embodiments, the measurements provided by a sensor 140 may indicate that a blade 120 should be dressed or replaced.
In some embodiments, a sensor 140 may measure a position of the corresponding blade 120 relative to the sensor 140. For example, the sensor 140 may use a laser to measure the distance that the blade 120 protrudes from an end of the arm 112. In this manner, the position of the blade 120 may be more precisely determined. In some cases, the sensor 140 may be used with the actuator 122 to more precisely or accurately adjust the position of the blade 120.
In some embodiments, a sensor 140 may measure a roughness of the corresponding blade 120. As an illustrative example, FIG. 10B shows a magnified view of an edge of a blade 120. The sensor 140 may be configured to measure surface variation of the edge of the blade 120, such as a maximum variation of the blade 120, indicated in FIG. 10B as R1. In some embodiments, a roughness measurement of the blade 120 may indicate that the blade 120 is in need of dressing or replacement. For example, a blade 120 may be dressed if a roughness, maximum height variation, average height variation, or the like exceeds a certain threshold.
In some embodiments, a sensor 140 may measure the absolute height or diameter of the corresponding blade 120. As an illustrative example, FIG. 10C shows a magnified view of an edge of a blade 120. The sensor 140 may be configured to measure a height of the blade 120, such as the minimum height of the blade 120, indicated in FIG. 10C as H1. In some embodiments, a height measurement of the blade 120 may indicate that the blade 120 is in need of dressing or replacement. For example, a blade 120 may be dressed or replaced if a minimum height H1 of the blade is less than a certain threshold (e.g., threshold Tl indicated in FIG. 10C).
FIG. 12 illustrates a schematic cross-sectional view of a portion of a trimming tool 400, in accordance with some embodiments. The trimming tool 400 may be similar to other trimming tools described herein, except that a single blade 120 is configured to two workpieces 50A-B. For example, the trimming tool 400 comprises an upper platen 104A that holds a workpiece 50A above the blade 120, and a lower platen 104B that holds a workpiece 50B below the blade 120. In this manner, the blade 120 may trim the workpieces 50A-B simultaneously. In some cases, the blade 120 may trim the workpieces 50A-B sequentially. The trimming tool 400 also comprises a cover 410 between the workpieces 50A-B that prevents particles or debris from accumulating on the lower workpiece 50B. The use of the trimming tool 400 allows for the rate that workpieces are trimmed to be increased.
Embodiments described herein have advantages. The trimming tools described herein allow for multi-blade dressing and multi-workpiece trimming at the same time. This can reduce time spent dressing blades and increase the rate at which workpieces are trimmed. Inspection tools, such as sensors, are also used to monitor blade, workpiece, and dressing board conditions to achieve higher yield, more efficient dressing, and easier maintenance. The trimming tools described herein allow for blades to be automatically dressed as needed.
In accordance with some embodiments of the present disclosure, an apparatus includes a first platen configured to hold a first workpiece; a first dressing board; and blade holder including arms extending from a central axis, wherein the blade holder is configured to hold a blade at an end of each respective arm, wherein the blade holder is operable to rotate around the central axis, wherein the blade holder is configured to trim the first workpiece using at least one blade, wherein the blade holder is configured to dress at least one blade on the first dressing board. In an embodiments, the apparatus includes a second platen configured to hold a second workpiece, wherein the blade holder is configured to simultaneously trim the first workpiece using one blade and trim the second workpiece using another blade. In an embodiment, the apparatus includes a second dressing board, wherein the blade holder is configured to simultaneously dress one blade on the first dressing board and another blade on the second dressing board. In an embodiment, wherein the blade holder has four arms. In an embodiment, the apparatus includes a sensor arm configured to measure a condition of a trimmed region of the first workpiece. In an embodiment, the blade holder includes a sensor configured to measure a condition of a blade held by the blade holder. In an embodiment, each arm of the blade holder includes an actuator, wherein each actuator is configured to extend or retract the blade at the end of the respective arm. In an embodiment, the first dressing board includes a first region corresponding to a first blade grit size and a second region corresponding to a second blade grit size.
In accordance with some embodiments of the present disclosure, a trimming tool includes a blade holder comprising arms, wherein the blade holder holds blades, wherein each arm holds a respective blade; platens, wherein each platen is configured to hold a respective wafer, wherein the platens are aligned with a first set of arms; and dressing boards, wherein the dressing boards are aligned with a second set of arms. In an embodiment, the blades are in a cross-shaped arrangement. In an embodiment, the blades include at least two different types of blades. In an embodiment, the dressing boards include at least two different types of dressing boards. In an embodiment, the blade holder is operable to rotate to align the plurality of platens with the second set of arms and the plurality of dressing boards with the first set of arms. In an embodiment, the platens include a first platen that is located above a second platen. In an embodiment, each dressing board is configured to rotate independently.
In accordance with some embodiments of the present disclosure, a method includes rotating a blade holder to align a first blade of the blade holder with a first platen and a second blade of the blade holder with a first dressing board; trimming a first workpiece on the first platen using the first blade; dressing the second blade using the dressing board; rotating the blade holder to align the second blade of the blade holder with the first platen; and trimming a second workpiece on the first platen using the second blade. In an embodiment, the method includes rotating the dressing board after dressing the second blade. In an embodiment, rotating the blade holder to align the first blade with the first workpiece also aligns a third blade with a third workpiece. In an embodiment, the method includes trimming the third workpiece using the third blade while the first workpiece is trimmed using the first blade. In an embodiment, the first blade has a course grit size and the second blade has a fine grit size.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
