Abstract:
In a first aspect, a method is provided for adjusting tension of a belt of a semiconductor device manufacturing tool. The first method includes (1) coupling an elastic element between a pulley coupled to the belt and a fixed surface of the semiconductor device manufacturing tool; and (2) compressing or decompressing the elastic element so as to adjust at least one of a height and a tilt of the pulley and a tension of the belt coupled to the pulley. Numerous other aspects are provided.

Description:
[0001]     The present application claims priority from U.S. Provisional Patent Application Ser. No. 60/600,284, filed Aug. 10, 2004, and titled “METHODS AND APPARATUS FOR ADJUSTING BELT TENSION OF A SCRUBBER” which is hereby incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to semiconductor device manufacturing, and more particularly to methods and apparatus for adjusting belt tension of a semiconductor device manufacturing tool such as a scrubber.  
       BACKGROUND  
       [0003]     In a conventional scrubber, a belt and pulley system generally is employed to rotate the scrubber brushes of the scrubber. During use, belt length and/or pulley position may vary, and belt tension may need to be adjusted. In one conventional design, the pulleys that drive the scrubber brushes of a scrubber are coupled to a mounting block, and belt tensioning requires adjustment of mounting block position. However, adjusting mounting block position may place excessive stress on the screws, tapped holes or other fasteners of the mounting block, which may result in unwanted wear and/or particle formation.  
         [0004]     Accordingly, methods and apparatus for adjusting belt tension of a scrubber are desired.  
       SUMMARY OF THE INVENTION  
       [0005]     In a first aspect of the invention, a method is provided for adjusting tension of a belt of a semiconductor device manufacturing tool. The first method includes (1) coupling an elastic element between a pulley coupled to the belt and a fixed surface of the semiconductor device manufacturing tool; and (2) compressing or decompressing the elastic element so as to adjust at least one of a height and a tilt of the pulley and a tension of the belt coupled to the pulley.  
         [0006]     In a second aspect of the invention, a method is provided for adjusting tension of a belt of a scrubber. The method includes (1) coupling an elastic element between a pulley coupled to the belt and a fixed surface of the scrubber; and (2) compressing or decompressing the elastic element so as to adjust at least one of a height and a tilt of the pulley and a tension of the belt coupled to the pulley.  
         [0007]     In a third aspect of the invention, a scrubber is provided that includes (1) a lid; (2) an elastic element coupled to the lid; (3) a pulley coupled to the elastic element and adapted to couple to a belt; and (4) at least one adjustment device coupled to the lid and adapted to compress or decompress the elastic element so as to adjust at least one of a height and a tilt of the pulley and a tension of any belt coupled to the pulley.  
         [0008]     In a fourth aspect of the invention, an apparatus is provided for adjusting belt tension of a semiconductor device manufacturing tool. The apparatus includes (1) a mounting block; (2) a pulley coupled to the mounting block and adapted to couple to a motor via a belt; (3) a mounting plate; (4) an elastic element coupled between the mounting plate and the mounting block; (5) a plurality of adjustment devices that couple the elastic element between the mounting plate and the mounting block; and (6) a plurality of nuts coupled to the mounting block and the plurality of adjustment devices. Rotation of each adjustment device causes (a) compression or decompression of the elastic element; and (b) adjustment at least one of a height and tilt of the mounting block and the pulley coupled to the mounting block so as to adjust a tension of any belt coupled to the pulley. Numerous other aspects are provided in accordance with these and other aspects of the invention.  
         [0009]     Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0010]      FIG. 1  is a side view of an apparatus for adjusting belt tension of a semiconductor device manufacturing tool in accordance with an embodiment of the present invention.  
         [0011]      FIG. 2  is a front view of the apparatus for adjusting belt tension of a semiconductor device manufacturing tool in accordance with an embodiment of the present invention.  
         [0012]      FIG. 3  is a cross-sectional front view of the apparatus for adjusting belt tension of a semiconductor device manufacturing tool in accordance with an embodiment of the present invention.  
         [0013]      FIG. 4  is an isometric view of the apparatus for adjusting belt tension of a semiconductor device manufacturing tool in accordance with an embodiment of the present invention.  
         [0014]      FIG. 5  is a side view of a shim in accordance with an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0015]     The present invention provides methods and apparatus for adjusting belt tension (of a semiconductor device manufacturing tool such as a scrubber). More specifically, the present invention provides methods and apparatus for adjusting a position of a mounting block to which a belt is operatively coupled, without placing excessive stress on components of the semiconductor device manufacturing tool. Unwanted particle formation thereby may be reduced.  
         [0016]      FIG. 1  is a side view of an apparatus  101  for adjusting belt tension of a semiconductor device manufacturing tool  103  (shown in phantom) in accordance with an embodiment of the present invention. With reference to  FIG. 1 , the apparatus  101  includes a mounting plate  105  coupled to a mounting block  107  via an elastic element (or member)  109 . The mounting plate  105  may be, for example, a portion of a lid  111  of a tank (e.g., a brush box) included in the semiconductor device manufacturing tool  103 . In one embodiment, the mounting plate  105  is about two inches wide, one inch long and less than or equal to about ¼ inch thick (although, the mounting plate  105  may be dimensioned differently). The mounting plate  105  may be formed from stainless steel. Alternatively, the mounting plate  105  may be formed from one or more additional materials or different materials. Similarly, the mounting block  107  may be about 50 mm wide, 25 mm long and 24 mm thick (although, the mounting block  107  may be dimensioned differently). The mounting block  107  may be formed from plastic, such as a thermoplastic polyester (e.g., Ertalyte® available from Quadrant Engineering Plastic Products). Alternatively, the mounting block  107  may be formed from one or more additional materials or different materials.  
         [0017]     Further, the elastic element  109  may be about 1½ inches long, one inch wide and ½ inch thick (although, the elastic element  109  may be dimensioned differently). The elastic element  109  may be formed from a fluoroelastomer (e.g., Viton® available from Dupont) or EPDM. Alternatively, the elastic element  109  may be formed from one or more additional materials or different materials. The elastic element  109  is adapted to compress (e.g., between the mounting plate  105  and the mounting block  107 ) as described further below.  
         [0018]     The apparatus  101  includes a plurality of adjustment mechanisms (e.g., screws  113 ) adapted to couple the elastic element  109  between the mounting plate  105  and the mounting block  107  (e.g., in cooperation with a plurality of nuts (not shown in  FIG. 1 ;  303  in  FIG. 3 )). Adjustment mechanisms other than the screws  113  and/or nuts  303  may be employed (e.g., bolts, etc.). In one embodiment, the plurality of adjustment screws  113  may be 4 mm screws and formed from stainless steel or titanium (although, another size and/or material may be used). The apparatus  101  includes four adjustment screws  113   a - d  (only two shown in  FIG. 1 ), and therefore, four nuts  303   a - d . However, a larger or smaller number of adjustment screws  113  and corresponding nuts  303  may be employed.  
         [0019]     A pulley  115   a  adapted to receive a belt  117   a  (shown in phantom) is coupled to the apparatus  101 . For example, a block (or gripper)  119  including a pneumatic actuator, may couple to the mounting block  107  (e.g., a bottom surface of the mounting block  107 ) of the apparatus  101 . The pulley  115   a  is coupled to a corresponding pulley housing  121   a , which is movably coupled to the block  119 . The semiconductor device manufacturing tool  103  may include two pulleys  115   a - b  (only one pulley  115   a  shown in  FIG. 1 ) that are coupled to the apparatus  101  via corresponding pulley housings  121   a - b  ( FIG. 2 ). Each pulley  115   a - b  is further adapted to couple to a corresponding brush coupling  123   a - b  to which a scrubber brush (e.g., employed during semiconductor device manufacturing) (not shown) may couple. Another configuration may be employed to couple the pulleys  115   a - b  to the apparatus  101 . The block/gripper  119  may be employed to move the brush couplings  123   a - b  (and any brushes attached thereto) together for scrubbing of a substrate or apart during loading of a substrate into or out of the semiconductor device manufacturing tool  103 .  
         [0020]      FIG. 2  is a front view of the apparatus  101  of  FIG. 1  in accordance with an embodiment of the present invention. With reference to  FIG. 2 , the block  119  coupled to the apparatus  101  includes a rail  201  to which the pulley housings  121   a - b  are movably coupled. More specifically, the pulley housings  121   a - b  may employ the rail  201  to slide along a y-axis, thereby moving brushes (not shown) coupled to the pulley housings  121   a - b  (via brush couplings  123   a - b ) toward or away from each other.  
         [0021]     Belts  117   a - b  coupled to respective pulleys  115   a - b  are also coupled to corresponding lower pulleys  125   a - b , which in the embodiment shown have a fixed position (e.g., inside the tank of the semiconductor device manufacturing tool  103 ). For example, the lower pulleys  125   a - b  may be part of a gear reducer, which translates motion outside of the tank into motion of the two lower pulleys  125   a - b . Consequently, rotation of the lower pulleys  125   a - b  causes the pulleys  115   a - b  coupled to the pulley housings  121   a - b  and brushes connected thereto to rotate.  
         [0022]     When the belts  117   a - b  are installed on the pulleys  115   a - b  coupled to the pulley housings  121   a - b , a load (e.g., tension) is applied to the pulleys  115   a - b  and the belts  117   a - b . As described below, the present invention provides methods and apparatus for adjusting such tension.  
         [0023]      FIG. 3  is a cross-sectional front view of the apparatus  101  for adjusting belt tension of the semiconductor device manufacturing tool  103  in accordance with an embodiment of the present invention. With reference to  FIG. 3 , each of the mounting plate  105 , elastic element  109  and mounting block  107  is adapted to receive the plurality of adjustment screws  113   a - d . More specifically, the mounting plate  105 , elastic element  109  and mounting block  107  include holes for receiving the plurality of adjustment screws  113   a - d . Further, the mounting block  107  includes a housing  301   a - d  (only  301   b  and  301   c  shown in  FIG. 3 ) for each nut  303   a - d  (only  303   b  and  303   c  shown in  FIG. 3 ). Each housing  301   a - d  is sized and shaped so as to prevent its respective nut  303   a - d  from rotating when the adjustment screw  113   a - d  (only  113   b  and  113   c  shown in  FIG. 3 ) corresponding to the nut  303   a - d  is rotated. In one embodiment, one or more (e.g., all) of the nuts  303   a - d  are polygonal, for example, and the corresponding nut housings  301   a - d  are shaped accordingly. Alternatively, the nuts  303   a - d  and corresponding nut housings  301   a - d  may be shaped differently. For example, in one or more embodiments, the nuts  303   a - d  may be spherical or the like (e.g., a shape with a similar range of motion), and the nut housings  301   a - d , which are adapted to receive the spherical nuts  303   a - d , are shaped accordingly. In either case, each nut  303   a - d  is adapted so as not to rotate when a corresponding adjustment screw  113   a - d  is turned (e.g., loosened or tightened slightly). More specifically, a nut  303   a - d  does not follow its corresponding adjustment screw  113   a - d  when the adjustment screw  113   a - d  is turned.  
         [0024]     Additionally, as described below, each nut  303   a - d  may tilt (e.g., tilt slightly) when an adjustment screw  113   a - d  corresponding to the nut  303   a - d  tilts. More specifically, in the former embodiment, when a screw corresponding to a polygonal nut  303   a - d  tilts, the polygonal nut  303   a - d  coupled to the screw also tilts or pivots (which deforms the nut housing  301   a - d  of the mounting block  107 ). Similarly, in the latter embodiment, when a screw corresponding to a spherical nut  303   a - d  tilts, the spherical nut  303   a - d  coupled to the screw also tilts or pivots. Pivoting of a spherical nut, however, does not generally deform the nut housing. In one embodiment, each nut  303   a - d  has an angular range of movement or degree of freedom of about 2-3 degrees (although in other embodiments each nut  303   a - d  may have a larger or smaller angular range of movement or degree of freedom).  
         [0025]     As shown in  FIG. 3 , the mounting block  107  may be adapted to receive a plurality of screws  305  that couple the mounting block  107  to the block  119  (which may include an actuator for moving the brush couplings  123   a - b  together or apart as previously described). For example, the mounting block  107  may include a plurality of holes for receiving the block screws  305 ; and the block  119  may include tapped holes adapted to receive the block screws  305 . Further, the mounting plate  105  may be adapted to receive one or more removable installation pins  307 , which may be used to provide alignment during pre-installation.  
         [0026]      FIG. 4  is a schematic representation of an isometric view of the apparatus  101  in accordance with an embodiment of the present invention. With reference to  FIG. 4 , the apparatus  101  for adjusting belt tension of a semiconductor device manufacturing tool  103  may include a locking plate  401  adapted to couple to the mounting plate  105  (e.g., a top surface of the mounting plate  105 ) via a plurality of locking screws  403  or other fasteners. For example, the locking plate  401  may include a plurality holes and the mounting plate  105  may include a plurality tapped holes for receiving corresponding locking screws  403 . When installed, the locking plate  401  (e.g., a bottom surface of the locking plate  401 ) is coupled (e.g., secured) to heads of the adjustment screws  113   a - d . The locking plate  401  may push heads of the locking screws  113   a - d  into the mounting plate  105 . In this manner, once the plurality of adjustment screws  113   a - d  are adjusted, the locking plate  401  may be employed to prevent movement (e.g., rotation) of the adjustment screws  113   a - d , for example, due to vibration during semiconductor device manufacturing.  
         [0027]     In one embodiment, the locking plate  401  is about 50 mm long, about 30 mm wide and about 8 mm thick (although, the locking plate  401  may be dimensioned differently). The locking plate  401  may be formed from stainless steel or any other suitable material. The locking screws  403  may be made of stainless steel, titanium or any other suitable material.  
         [0028]     The operation of the apparatus  101  is now described with reference to  FIGS. 1-4 . In operation, at least one of the plurality of adjustment screws  113   a - d  may be adjusted (e.g., tightened or loosened by turning), for example, by a user. In response to such adjustment, the elastic element  109  may compress or decompress. For example, if one of the adjustment screws  113   a - d  is tightened, a portion of the elastic element  109  surrounding the adjustment screw  113   a - d  compresses.  
         [0029]     Compression or decompression of the elastic element  109  (e.g., a portion of the elastic element  109  surrounding an adjusted adjustment screw  113   a - d ) may cause the longitudinal axis of the adjustment screw  113   a - d  to change (e.g., tilt). Consequently, the adjustment screws  113   a - d  have some freedom of angular movement relative to the mounting block  107  during adjustment. (Accordingly, the respective longitudinal axes of two or more of the plurality of adjustment screws  113   a - d  may not be parallel.)  
         [0030]     Because a portion of the elastic element  109  surrounding any adjusted adjustment screw  113   a - d  compresses or decompresses, the height (e.g., relative to a tank bottom) or tilt of the mounting block  107  may be adjusted. Adjusting all screws  113   a - d  equally raises or lowers the mounting block without tilting the same. In this manner, the mounting block  107  may move along a z-axis (e.g., vertically).  
         [0031]     Adjusting fewer than all of the adjustment screws  113   a - d  or adjusting all adjustment screws  113   a - d  unequally may compress or decompress the elastic element  109  unevenly and cause the mounting block  107  to tilt relative to an xy-plane and/or a yz-plane ( FIG. 1 ). Additionally or alternatively, adjusting the adjustment screws  113   a - d  may cause the mounting block to tilt relative to an xz-plane. In one embodiment, the mounting block  107  may move about 0.1 to 0.2 inches relative to the xy-plane and/or yz-plane. In other embodiments, the mounting block  107  may move a larger or smaller distance relative the xy-plane and/or the yz-plane.  
         [0032]     Components coupled to the mounting block  107 , such as the pulley housings  121   a - b , pulleys  115   a - b , brush couplings  123   a - b  and/or brushes coupled thereto, may be adjusted in a similar manner. By adjusting the height and/or tilt of a pulley  115   a - b  coupled to the mounting block  107 , a tension of a corresponding belt  117   a - b  coupled thereto may be adjusted. In this manner, the apparatus  101  may accommodate a belt  117   a - b  which is too tight or too loose, and/or may accommodate for a difference in lengths of belts  117   a - b  coupled to the apparatus  101 . Further, belt slippage and/or misalignment (e.g., when a belt climbs on a pulley flange), for example, may be prevented without placing excessive stress on the screws  113   a - d  and/or nuts  303   a - d  (or other components) of the apparatus  101 . Through adjustment of the mounting block, an axis A of a pulley  115   a - b  may be at an incline from a horizontal axis (e.g., x-axis) when the pulley is unloaded (e.g., not coupled to a belt  117   a - b ) as shown in  FIG. 1  and, may be horizontal or approximately horizontal when the pulley  115   a - b  is under load (e.g., when a belt  117   a - b  is coupled to the pulley  115   a - b  and/or when a brush is coupled to a brush coupling  123   a - b ).  
         [0033]     As described above, after adjustment of the adjustment screws  113   a - d , a locking plate  401  may be coupled to the heads of the adjustment screws  113   a - d . In this manner, the locking plate  401  prevents movement of the adjustment screws  113   a - d  (e.g., further adjustment of the adjustment screws  113   a - d  or movement of the adjustment screws  113   a - d  due to vibration during semiconductor device manufacturing).  
         [0034]      FIG. 5  is a schematic representation of a side view of a shim  501  in accordance with an embodiment of the present invention. With reference the  FIG. 5 , the shim  501  may be coupled to (e.g., between) the mounting plate  105  and elastic element  109 . The shim  501  may be formed from plastic, such as a thermoplastic polyester (e.g., Ertalyte® available from Quadrant Engineering Plastic Products). Alternatively, the shim  501  may be formed from additional materials or different materials. The shim  501  is dimensioned to compensate for a misalignment greater than the tolerance of the apparatus  101  (e.g., a gross vertical misalignment). For example, if a gap is created between the mounting plate  105  and elastic element  109  when a belt  117   a - b  is coupled to a pulley  115   a - b  (because the elastic element  109  is too thin), the shim  501  may be employed to ensure that the elastic element  109  is coupled to the mounting plate  105 , thereby allowing the elastic element  109  to compress, and adjustment of at least one of a height and a tilt of the mounting block  107 .  
         [0035]     The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and methods which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, in embodiments described above, the elastic element  109  may have a specific height, width and thickness. Alternatively, the elastic element  109  may be formed from a plurality of springs corresponding to and coupled to (e.g., surrounding) the plurality of adjustment screws  113   a - d  or other adjustment mechanisms. In such embodiments, the plurality of springs provide similar adjustability.  
         [0036]     Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.