Patent Publication Number: US-9895725-B1

Title: Disk clamp and motor hub cleaning with stamping adhesive

Description:
BACKGROUND 
     Embodiments relate to the cleaning of selected structures of devices. More particularly, embodiments related to the cleaning of selected structures of data storage devices being manufactured and/or assembled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an assembly according to one embodiment. 
         FIG. 2  shows a side view of the assembly of  FIG. 1 . 
         FIG. 3  is a view of an end effector assembly, according to one embodiment. 
         FIG. 4  is a view of a sticky tape dispenser suitable for use with the assembly of  FIG. 1 , according to one embodiment. 
         FIG. 5  shows a portion of the assembly of  FIG. 1 , together with a presented data storage device being manufactured, according to one embodiment. 
         FIG. 6  is a detail of  FIG. 5 , showing additional features thereof, according to one embodiment. 
         FIG. 7  is another detail of  FIG. 5 , showing the motor hub and disk clamp of a data storage device with which embodiments may be practiced. 
         FIG. 8  is a flowchart of a method according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     When a disk pack comprising one or more disk is installed in a data storage device comprising a hard disk drive, the disk pack is fitted on a spindle motor hub and a disk clamp is installed on the motor hub to secure the disk(s) of the disk pack to the hub of the spindle motor. However, friction between the aluminum/stainless steel disk clamp and the aluminum/stainless steel motor hub creates stainless steel and aluminum particulates and debris that contaminate the disk clamp and the motor hub. As a result, the disk clamp and the motor hub need to be cleaned. The disk clamp and motor hub cleaning may be provided by a Clean And Purge (CAP) tool that carries out a vacuum and purge process. However, the CAP tool may cause an oil leak due to differential pressure between the outside environment and the pressurized oil. Removing the CAP tool avoids contaminating the data storage devices with leaking oil, but increases the backend failure rate caused by the aforementioned stainless steel and aluminum particle contamination on the disk clamp and the motor hub. 
     One embodiment is an assembly configured to clean one or more selected structures of a device. In one embodiment, the device may comprise a data storage device. For example, the data storage device may comprise a solid state data storage device, a hard disk drive and/or a hybrid thereof. In one embodiment, the structure or structures being cleaned are structures of a device being manufactured and/or assembled. For example, one implementation may comprise an assembly as shown  FIGS. 1-6 , configured to clean structures such as a spindle motor hub and a disk clamp of a data storage device comprising a hard disk drive being manufactured and/or assembled. An exemplary spindle motor hub and disk clamp are shown in  FIG. 7  at  702  and  704 , respectively. In  FIG. 7 , the spindle motor, of which only the hub  702  is visible, is configured to rotate the disk  706 , which is clamped onto the motor hub  702  by disk clamp  704 . The spindle motor may then rotate the disk  602  to thereby enable the head(s) on the actuator assembly  708  to read and write data on the disk  602 . However, it is to be noted that embodiments are not limited to cleaning spindle motor hubs and disk clamps of data storage devices. Indeed, embodiments may readily be adapted to the cleaning of other selected structures of other devices, whether already assembled or under manufacture. 
     Collectively referring to  FIGS. 1-6 , one embodiment is an assembly  100  configured to clean one or more selected structures of a device. The assembly  100  may comprise an end effector assembly  202 . Structures of one implementation of such an end effector assembly  202  are also shown in  FIG. 3 . As shown therein, the end effector assembly  202  may comprise a first end effector  204  and a second end effector  206 . The end effector assembly of  FIG. 3  is shown, as suggested at  209 , as rotatable about an axle  208 . In operation, one surface of each of the first and second end effectors faces the selected structure(s) to be cleaned. These surfaces are shown in  FIG. 3  at  302  and  304 . According to one embodiment and in operation of the assembly  100 , the surfaces  302 ,  304  face the selected structures (such as motor hub  702  and disk clamp  704 ) to be cleaned, and comprise a layer of material  205 ,  207 . According to one embodiment, the end effector assembly  202  may be configured to selectively move the material  205  or  207  towards and against the selected structure(s) such that the material  205 ,  207  remains on the facing surface  302 ,  304  of the end effector assembly  202  and retains, when the end effector assembly  100  is moved away from the device to be cleaned, at least some particulates previously on the selected structure(s). 
     That is, with reference back to  FIG. 3 , each of the facing surfaces  302 ,  304  may comprise a material or layer of material  205 ,  207  thereon. This material may be configured according to the selected structure that it is to clean. For example, the first end effector  204  comprises a first facing surface  302  onto which a (layer of) material  205  may be disposed. This material  205  may be configured (e.g., with regard to composition, thickness, shape) according to a first selected structure, for example, the motor hub shown at  702  in  FIG. 7 . Similarly, the second end effector  206  comprises a second facing surface  304  onto which a (layer of) material  207  may be disposed. This material  207  may be configured (e.g., with regard to composition, thickness, shape) according to a second selected structure such as, for example, the disk clamp shown at  704  in  FIG. 7 . The material  207  may be configured to avoid contact with other, adjacent structures. For example, the material  207  may be configured to contact the motor hub  702  but to avoid contact with the motor hub&#39;s tie shaft  705 , to avoid oil contamination. For example, the material  207  may have a circular shape that contacts the disk clamp or the motor hub but that includes a center hole or void to avoid making contact with the tie shaft  705 . 
     Indeed, as best shown in  FIG. 6 , the material  205  on the first facing surface of the first end effector  204  may be moved (lowered as suggested at  604  in the implementation shown in  FIG. 6 ) toward a presented data storage device. In so doing, the material  205  may be moved and pressed against the motor hub  702 . In an alternative embodiment, the selected structure(s) to be cleaned may be moved towards the material  205  or the material  205  and the selected structure(s) may be moved toward one another. To protect the surface of the disk  602 , a protective table  215  may be moved over the disk  602 . The protective table  215 , as best shown in  FIG. 6 , may comprise an opening therein to allow the material  205 ,  207  on the facing surface of the end effector to reach and make contact with the selected structures to be cleaned (in this case, the spindle motor hub and the disk clamp of a data storage device under manufacture). The protective table  215  may be configured to slide into position over the disk  602 , as suggested by arrow  606  in  FIG. 6 . According to one embodiment, the material  205  may be selected such that, when the end effector assembly  202  is moved away from the data storage device, the material  205  remains on the facing surface of the end effector assembly  202  (i.e., it does not become adhered to the selected structure(s)) and retains at least some particulates previously on the motor hub  702 . In retaining at least some of the (e.g., aluminum, steel, dust) particulates previously on the motor hub  702 , the motor hub  702  is cleaned (or at least rendered cleaner) and rendered ready for next manufacturing steps and/or sealing of the data storage device. According to one embodiment, the material  205  on the facing surface of the end effector assembly  202  may be shaped and selected to be sufficiently thick and compliant as to conform to at least some surface features of the motor hub  702  when moved and pressed there against. The material  205  may be selected to capture at least some of the undesirable particulates that may be present in the motor hub  702 . For example, the material may exhibit a selected degree of tackiness that causes particulates to adhere thereto. The material  205  may be conductive and charged to attract particulates on an oppositely-charged device being cleaned. The material  205  may be sufficiently compliant so as to at least partially envelop, encapsulate or invaginate the particulates and lift them off of the selected structure, such as the motor hub  702 . The structure and/or material architecture may be selected to achieve the greatest particulate lifting capability and the ability to conform to the surface topology of the selected structure so as to be able to reach within the nooks and crannies of the selected structure, and to lift particulates lying therein away from the surface thereof. 
     Thereafter, the end effector assembly  202  may be rotated about axis  208  and the second end effector  206  used to move material  207  towards and against the disk clamp  704  to lift at least some of the particulates previously thereon. In each case, the materials  205 ,  207  may be retained by the first and second end effector  204 ,  206  as the end effector is moved away from the selected structures to be cleaned. It is to be noted that a same structure may be cleaned by each of the first and second end effectors  204 ,  206 . For example, the first end effector  204  and material  205  may make a first pass at removing at least some particulates from a selected structure and the second end effector  206  and material  207  may make a second pass and clean at least some of the remaining particulates from the same selected structure. Materials  205 ,  207  may be shaped and configured identically. Alternatively, the materials  205 ,  207  may be shaped and/or configured differently from one another. As materials  205 ,  207  may be selected according to the structures to be cleaned and/or the nature of the anticipated particulates, the materials  205 ,  207  on each of the first and second end effectors  204 ,  206  may be dissimilar in composition, shape, thickness, porosity, compliance and/or other material characteristics. 
     According to one embodiment, material  205 ,  207  may comprise a polymeric adhesive. In one embodiment, at least one of the materials  205 ,  207  may comprise Dycem®, a material manufactured by Dycem Ltd USA of Warwick, R.I. Indeed, after the Dycem material  205 ,  207  is stamped onto and contacts with the motor hub  702  and disk clamp  704 , it is pulled away as the end effector  204 ,  206  is moved away from the data storage device. At least some of the particulates on the motor hub  702  and the disk clamp  704  are lifted away, captured by the Dycem material  205 ,  207 . The Dycem material  205 ,  207  is sufficiently flexible and soft so that it follows, at least to some degree, the contours of the motor hub  702  and of the disk clamp  704  for better cleaning effectiveness. It is to be noted that the material  205 ,  207  may be molded so as to conform to the shape of the selected structures. That is, the materials  205 ,  207  may be molded to conform to the shape and surface topography of both the motor hub  702  and the disk clamp  704  or whatever other selected structure is to be cleaned of particulates. 
     According to one embodiment, the material  205 ,  207  may be configured to be re-usable. So as not re-contaminate the structures selected for cleaning with particulates captured from a previous pass, the materials  205 ,  207 , according to one embodiment, may themselves be configured to be cleaned. According to one embodiment, the materials  205 ,  207  may be cleaned of at least some of the particulates and/or undesirable impurities adhered thereto by, for example, pressing the materials  205 ,  207  against sticky tape (or other functionally-similar surface), to which at least some of the particulates previously adhered to the material  205 ,  207  would stick. Best results may be obtained if a clean portion  220  of sticky tape is presented to the materials  205 ,  207  each time the materials  205 ,  207  are to be cleaned. Toward that end, the end effector  204 ,  206  may be configured to press the material  205 ,  207  with the retained particulates against a (preferably, clean) portion of the sticky tape, such that at least some of the particulates retained by the material  205 ,  207  adhere to the portion of the sticky tape. For that purpose, the assembly  100  may comprise a sticky tape dispenser  212  as best shown in  FIGS. 1, 2 and 4 . As shown therein, the sticky tape dispenser  212  may be loaded with a roll of sticky tape  218 , dispensed from a first roll  216  and taken up by a second roll  214 . The sticky tape  218  may be routed over a tape presenting surface  219  that may be dimensioned to accommodate the material  205 ,  207 . By pressing the materials  205 ,  207  with the retained particulates against the tape presenting surface  219  over which a clean portion  220  of sticky tape  218  is stretched, the particulates formerly captured by the materials  205 ,  207  may be transferred onto the sticky tape  218 . The sticky tape  218  with the transferred particulates now adhered thereto may be advanced (i.e., dispensed by first roll  216  and taken up by second roll  214 ), so as to cause a clean portion  220  of sticky tape  218  to be presented on the tape presenting surface  219 , in anticipation of another end effector cleaning cycle. A tape tensioner  222  may ensure that the sticky tape  218  is tensioned correctly. A new, clean roll may be loaded onto the sticky tape dispenser when all of the sticky tape has been used and taken up by the second roll  214 . 
       FIG. 8  is a flowchart of a method according to one embodiment. As shown therein, a method according to one embodiment may comprise presenting a data storage device being manufactured, as shown at B 81 . The presented data storage device being manufactured may comprise disk  602 , a motor configured to rotate the disk  602 , the motor comprising a motor hub  702  and a disk clamp  704  configured to clamp the disk  602  onto the motor hub  702 . As show at B 82 , the method may further comprise moving an end effector assembly  202  toward the presented data storage device and against the motor hub  702  and the disk clamp  704 , pressing against these selected structures. As shown, the end effector assembly  202  may comprise a material  205 ,  207  on a surface  302 ,  304  thereof that faces the motor hub  702  and the disk clamp  704 . The end effector assembly  202  may then be moved away from the data storage device, such that the material  205 ,  207  remains on the facing surface  302 ,  304  (preferably, none of it remains on the selected structures to be cleaned) of the end effector assembly  202  and retains at least some particulates previously on at least one of the motor hub  702  and the disk clamp  704 , as shown (not to scale) to the right of B 83  in  FIG. 8 . 
     While certain embodiments of the disclosure have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods, devices and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure. For example, those skilled in the art will appreciate that in various embodiments, the actual physical and logical structures may differ from those shown in the figures. Depending on the embodiment, certain steps described in the example above may be removed, others may be added. Also, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Although the present disclosure provides certain preferred embodiments and applications, other embodiments that are apparent to those of ordinary skill in the art, including embodiments which do not provide all of the features and advantages set forth herein, are also within the scope of this disclosure. Accordingly, the scope of the present disclosure is intended to be defined only by reference to the appended claims.