Wafer polishing apparatus for adjusting height of wheel tip

Abstract

In a wafer polishing apparatus, the height of the wheel tip can be adjusted. The wafer polishing apparatus includes a wheel tip constructed and arranged to be in direct contact with a wafer; a spindle shaft configured to receive power to enable rotation of the wheel tip; a wheel shank positioned at a lower part of the spindle shaft and supporting the wheel tip, the wheel tip not being directly fixed thereto; and a moving shaft having a first side on which the wheel tip is mounted and an opposite side to which the spindle shaft is connected, and relatively movable with respect to the spindle shaft.

1 . A wafer polishing apparatus comprising:
 a spindle shaft rotated by a main motor;   a wheel shank axially and rotatably coupled to the spindle shaft;   a moving shaft engaged with the spindle shaft by a gear to be rotated; and   a wheel tip coupled to the moving shaft and supported by the wheel shank, constructed and arranged to polish a wafer.   
     
     
         2 . The wafer polishing apparatus according to  claim 1 , wherein the gear comprises:
 a screw jack coupled to the moving shaft and having a female thread; and   a lead screw coupled to the spindle shaft by a bearing and having a male thread.   
     
     
         3 . The wafer polishing apparatus according to  claim 2 , further comprising a step motor supported by the spindle shaft, and rotating the lead screw to straightly move the moving shaft with respect to the spindle shaft in a vertical direction. 
     
     
         4 . The wafer polishing apparatus according to  claim 2 , wherein the wheel shank comprises:
 a spindle coupling part axially coupled to the spindle shaft; and   a cover part having a slide groove in which the wheel tip is supported or slid.   
     
     
         5 . The wafer polishing apparatus according to  claim 2 , wherein the moving shaft comprises:
 a connecting part to which the screw jack is integrally coupled; and   a slide part extending to a lower part of the connecting part and under which the wheel tip is mounted.   
     
     
         6 . The wafer polishing apparatus according to  claim 5 , wherein:
 the spindle shaft comprises a plurality of connecting holes extending in an axial direction thereof, and   the connecting part is connected within the spindle shaft in a cross shape, and slid along the connecting hole in an axial direction thereof.   
     
     
         7 . A wafer polishing apparatus comprising:
 a rotatable spindle shaft;   a wheel shank integrally fixed to the spindle shaft;   a moving shaft variably fixed to the spindle shaft; and   a wheel tip detachably mounted on the moving shaft.   
     
     
         8 . The wafer polishing apparatus according to  claim 7 , wherein:
 the wheel shank comprises a slide hole configured to conceal the wheel tip other than an exposed portion of the wheel tip in direct contact with a wafer, and   the moving shaft comprises a slide part slid in the slide hole together with the wheel tip.   
     
     
         9 . The wafer polishing apparatus according to  claim 8 , wherein the slide part further comprises an attachment groove positioned at a first end and to which the wheel tip is detachably attached, and
 the attachment groove has an open lower end so that the wheel tip can be inserted in an upward direction with respect to a longitudinal cross-section thereof.   
     
     
         10 . The wafer polishing apparatus according to  claim 9 , wherein:
 the slide part further comprises a fastening hole passing through both sides thereof and at least the attachment groove; and   a bolt is fastened to the fastening hole to fix the wheel tip inserted into the attachment groove.   
     
     
         11 . A wafer polishing apparatus comprising:
 a wheel tip constructed and arranged to be in direct contact with a wafer;   a spindle shaft configured to receive power to enable rotation of the wheel tip;   a wheel shank positioned at a lower part of the spindle shaft and supporting the wheel tip, the wheel tip not being directly fixed thereto; and   a moving shaft having a first side on which the wheel tip is mounted and a second side to which the spindle shaft is connected, and relatively movable with respect to the spindle shaft.   
     
     
         12 . The wafer polishing apparatus according to  claim 11 , wherein the wheel shank comprises:
 a spindle coupling part coupled to the spindle shaft at an upper center thereof; and   a cover part configured to expose a portion of the wheel tip at a lower edge thereof.   
     
     
         13 . The wafer polishing apparatus according to  claim 12 , wherein the wheel tip has a width W of 3 mm to 4 mm and a height H of 5 mm to 15 mm, and a height H 1  of the wheel tip exposed from the cover part is maintained within a range of 1 mm to 4 mm. 
     
     
         14 . The wafer polishing apparatus according to  claim 12 , wherein:
 the cover part further comprises a slide hole through which the wheel tip can vertically pass, and   as the slide part is slid downward from the slide hole, a height H 2  of the wheel tip concealed by the cover part is reduced, and the height H 1  exposed from the cover part is uniformly maintained within the range.   
     
     
         15 . The wafer polishing apparatus according to  claim 14 , wherein the slide hole corresponds to a shape of the wheel tip, and has a step between upper and lower parts thereof so that a hole gap at the upper part is larger then the thickness of the wheel tip, and a hole gap at the lower part is equal to or approximate to the thickness of the wheel tip with respect to a longitudinal cross-section thereof. 
     
     
         16 . The wafer polishing apparatus according to  claim 15 , wherein:
 a vertical surface of the step is a surface configured to support the wheel tip, and   a horizontal surface of the step comprises a stopper surface to prevent the moving shaft from lowering any further.   
     
     
         17 . The wafer polishing apparatus according to  claim 11 , wherein the moving shaft comprises:
 a connecting part movably connected to the spindle shaft; and   a slide part to which the wheel tip is detachably attached.   
     
     
         18 . The wafer polishing apparatus according to  claim 17 , further comprising a variable means configured to fix the moving shaft to the spindle shaft during polishing or to vary a position of the moving shaft when the wheel tip is worn down. 
     
     
         19 . The wafer polishing apparatus according to  claim 18 , wherein the variable means is a screw gear assembly, and
 the screw gear assembly comprises:
 a screw jack formed at the moving shaft; 
 a lead screw connected to the spindle shaft and passing through the screw jack; and 
 a step motor configured to rotate the lead screw, 
 wherein when the lead screw is rotated by the step motor, the screw jack moves longitudinally in a vertical direction depending on a rotational direction of the lead screw. 
   
     
     
         20 . The wafer polishing apparatus according to  claim 18 , wherein the variable means is a linear actuator, and
 the linear actuator comprises:
 a piston rod extending to be connected to the connecting part in a cross shape; and 
 a linear step motor configured to move the piston rod in a longitudinal direction thereof, 
 wherein when the linear step motor is driven, the piston rod moves longitudinally in a vertical direction.