JP6012302B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus for grinding a plate-like workpiece.

  BACKGROUND ART A grinding apparatus for grinding a plate workpiece such as a semiconductor wafer includes a holding table that holds the plate workpiece and a grinding spindle unit on which a grinding wheel is mounted at a lower end portion. For example, in the grinding apparatus described in Patent Document 1, a grinding spindle unit is supported by a grinding holder, and the grinding holder is supported in a cantilever manner so that it can be moved up and down by a grinding feed means having an advance / retreat shaft and a guide, As the grinding holder moves up and down driven by the grinding feed means, the grinding spindle unit also moves up and down.

JP 2011-161546 A

  However, when grinding a plate-like workpiece held on the holding table in the above grinding apparatus, the grinding area where the grinding wheel provided on the grinding wheel and the plate-like workpiece come into contact with each other and the vertical movement of the grinding spindle unit are guided. The grinding wheel is loaded by the reaction force from the holding table, and the grinding spindle unit rotates. There is a problem that the shaft is inclined and abnormal grinding of the grinding wheel or poor grinding occurs.

  The present invention has been considered in view of such problems, and it is an object of the present invention to prevent abnormal grinding of grinding wheels and poor grinding from occurring in a grinding apparatus by preventing the rotation shaft of the grinding spindle unit from tilting. And

The present invention relates to a rotatable holding table for holding a plate-like workpiece, a grinding means for grinding the plate-like workpiece held on the holding table, and a grinding feed direction in which the grinding means approaches or separates from the holding table. Grinding and feeding means for advancing and retreating, and positioning means for positioning the plate-like workpiece held by the holding table at a position facing a grinding wheel arranged in an annular shape on a grinding wheel mounted on the grinding means, the holding table holding In the grinding apparatus for in-feed grinding the upper surface of the plate-like workpiece by the grinding means, the grinding means is composed of a grinding spindle having a rotating shaft mounted with a grinding wheel and a spindle holder that supports the grinding spindle. The grinding feed means is arranged parallel to the grinding feed direction and guides the vertical movement of the spindle holder. The guide is composed of a guide and an advance / retreat shaft for advancing and retreating the spindle holder directed by the two guides in the grinding feed direction. The upper surface of the plate-like workpiece held by the holding table and the grinding wheel are plate-like. The grinding area in contact with the workpiece has an arc shape having the width of the grinding wheel in the radial direction of the grinding wheel around the axis of the rotating shaft, and the grinding means feeds the grinding means at a predetermined speed to the grinding area. When the grinding wheel presses the upper surface of the plate-like workpiece in FIG. 2, the grinding means presses the holding table positioned at the grinding position by the grinding load, and in the cross-sectional view, the centroid of the grinding region and the two guides Each axial center and the axial center of the advancing / retreating axis are arranged on one reference straight line.

  In the grinding apparatus, it is desirable to arrange the axis of the rotation axis on the reference straight line. In addition, a portal column having two guides and an advancing / retracting shaft for grinding and feeding the grinding means is provided, and the portal column has two column portions respectively supporting the two guides and two columns. In the case where the upper portion of the column portion is connected to the connecting portion, it is desirable that the centroid of the cross section of the column portion is arranged on the reference straight line. In addition, it is desirable that the midpoint of the straight line connecting the centroids of the respective cross sections of the two column portions coincides with the axis of the advance / retreat axis.

  In the present invention, the center of the grinding load, the axis of each of the two guides that guide the vertical movement of the spindle holder, and the axis of the advance / retreat axis that advances and retracts the spindle holder in the grinding feed direction are one reference straight line. Because it is placed above, even if the holding table is pressed by the grinding load when grinding plate-like workpieces, the rotation axis of the grinding spindle is difficult to tilt, preventing abnormal wear of grinding wheels and poor grinding can do.

  In particular, if the axis of the rotation axis of the grinding spindle is arranged on the reference straight line, the grinding means can be reliably prevented from tilting even if a reaction force is generated from the holding table due to the pressing by the grinding means. .

  Further, a portal column having two guides and an advancing / retracting shaft for grinding and feeding the grinding means connects the two column portions respectively supporting the two guides and the upper portions of the two column portions. If the centroid of the cross section of the column part is arranged on the reference straight line, the column part does not incline, so that it is possible to prevent the grinding means from inclining in the reference straight line direction.

  If the midpoint of the straight line connecting the centroids of the cross-sections of each of the two column parts coincides with the axis of the advance / retreat axis, there is no inclination in the grinding feed direction. The surface accuracy can be maintained.

It is a perspective view which shows an example of a grinding wheel. It is a cross-sectional view which shows typically the 1st example of the positional relationship of a holding table, a grinding means, and a grinding feed means. It is a cross-sectional view schematically showing a second example of the positional relationship among the holding table, the grinding means, and the grinding feed means. It is a cross-sectional view schematically showing a third example of the positional relationship among the holding table, the grinding means, and the grinding feed means. It is a cross-sectional view schematically showing a fourth example of the positional relationship among the holding table, the grinding means, and the grinding feed means. It is a cross-sectional view schematically showing a fifth example of the positional relationship among the holding table, the grinding means, and the grinding feed means.

  A grinding apparatus 1 shown in FIG. 1 includes a holding table 2 that holds a plate-like workpiece, a grinding means 3 that grinds the plate-like workpiece held by the holding table 2, and the grinding means 3 that approaches the holding table two times. Alternatively, it is provided with a grinding feed means 4 for moving back and forth in the grinding feed direction (Z-axis direction) that moves away.

  The holding table 2 is rotatable and is horizontally moved in the front-rear direction (Y-axis direction) with the expansion and contraction of the bellows-shaped cover member 21 by being driven by the positioning means 20. The holding surface 2a of the holding table 2 is formed in a conical surface having the rotation center as a vertex.

  The grinding means 3 includes a grinding spindle 30 having a rotating shaft 300 on which a grinding wheel 32 is mounted and a rotatable shaft, and a spindle holder 31 that supports the grinding spindle 30. On the lower surface of the grinding wheel 32, a grinding wheel 320 having a predetermined width in the radial direction around the axis 300a of the rotating shaft 300 is fixed on an arc.

  The grinding feed means 4 supports the spindle holder 31 so as to move up and down, and advances and retracts the two guides 40 arranged in parallel to the grinding feed direction and the spindle holder 40 directed by the two guides in the grinding feed direction. An advance / retreat axis 41 is provided. The advance / retreat shaft 41 is screwed into a nut structure provided inside the spindle holder 31.

  The two guides 40 and the advancing / retreating shaft 41 constituting the grinding feed means 4 are disposed in a portal column 42 disposed across the movement path of the holding means 2 in the Y-axis direction. The portal column 42 includes a column portion 420 that supports the two guides 40 and a connecting portion 421 that connects the upper portions of the two column portions 420.

  At the time of grinding the plate-like workpiece, first, the positioning means 20 shown in FIG. 1 positions the plate-like workpiece W held by the holding table 2 at a grinding position facing the grinding wheel 320 as shown in FIG. . When the holding table 2 rotates in a state where it is located at the grinding position, the rotating shaft 300 of the grinding means 3 rotates, and when the grinding feed means 4 grinds and feeds the grinding means 3 in the Z direction at a predetermined speed, the holding table 2 Since the holding surface 2a is a conical surface, the upper surface of the plate-like workpiece W and the lower surface of the grinding wheel 320 have the width of the grinding wheel 320 in the radial direction of the grinding wheel 32 about the axis 300a of the rotating shaft 300. In contact grinding in the grinding region 100 from the rotation center of the holding table 2 to the outer peripheral edge of the plate-like workpiece W, the upper surface of the plate-like workpiece W is pressed and in-feed grinding is performed. Further, the holding table 2 positioned at the grinding position is also pressed by the grinding load at that time.

  At this time, as shown in FIG. 2, the center of the grinding load, that is, the center 100 a of the grinding region 100, the axis 40 a of each of the two guides 40, the axis 41 a of the advance / retreat axis 41, and the column part 420. The centroid 420a is arranged on one reference straight line 200. Therefore, even if the holding table 2 is pressed by the grinding load and a load is applied to the grinding wheel 320, the grinding feed means 4 does not incline, so the rotary shaft 300 of the grinding spindle 30 supported by the grinding feed means 4 inclines. It is difficult to prevent abnormal wear of the grinding wheel 320 and poor grinding.

  In addition, since the midpoint of the straight line connecting the centroids 420a of the cross-sections of the two column portions 420 coincides with the axis 41a of the advance / retreat shaft 41, the grinding feed means 4 is inclined. Can be more reliably prevented, and the surface accuracy of the plate-like workpiece can be maintained.

  As shown in FIG. 3, the center 101a of the grinding region 101, the axis 40a of each of the two guides 40, the axis 41a of the advance / retreat axis 41, and the centroid 420a of the two column parts 420 are: In addition to being arranged on one reference straight line 201, the grinding apparatus 1a in which the axis 300a of the rotary shaft 300 is also located on the reference straight line 201 only prevents the grinding feed means 4 from being inclined. In addition, the rotation shaft 300 of the grinding spindle 30 can be more reliably prevented from tilting, and abnormal wear and grinding failure of the grinding wheel 320 can be prevented.

  Further, as in the grinding device 1b shown in FIG. 4, the axis 41a of the advance / retreat shaft 41 may be positioned between the centroid 420a of the two column portions 420 and the center 102a of the grinding region 102. Also in this case, the center 102a of the grinding region 102, the axis 40a of each of the two guides 40, the axis 41a of the advance / retreat axis 41, and the centroid 420a of the two pillars 420 are one. Since it is arranged on the reference straight line 202, the rotating shaft 300 of the grinding spindle 30 is difficult to be inclined, and it is possible to prevent abnormal wear or grinding failure of the grinding wheel 320.

  1-4 has a L-shaped cross section, but the cross-sectional shape of the column may be other than L-shaped. For example, as shown in FIG. 5, when the cross section of the two pillar portions 520 is a triangle, two guides 400 are disposed along the hypotenuse 520b, and the center 103a of the grinding region 103 and the two guides Since each axis 400a of the guide 400, the axis 41a of the advance / retreat axis 41, and the centroid 520a of the column portion 520 are arranged on one reference straight line 203, the rotation axis 300 of the grinding spindle 30 is obtained. Is difficult to tilt, and abnormal grinding of the grinding wheel 320 and poor grinding can be prevented.

  Further, as shown in FIG. 6, the cross section of the two column portions 620 has a shape in which a tapered surface 620 b is provided on the inner side of a substantially L shape, and two guides 401 are disposed along the tapered surface 620 b, The center 104 a of the grinding region 104, the respective axes 401 a of the two guides 401, the axis 41 a of the advance / retreat axis 41, and the centroid 620 a of the column part 620 are arranged on one reference straight line 204. Therefore, the rotating shaft 300 of the grinding spindle 30 is difficult to tilt, and abnormal grinding of the grinding wheel 320 and poor grinding can be prevented.

  The same applies to a grinding apparatus provided with a plurality of grinding means and grinding feed means. For each grinding means and grinding feed means, at least the center of the grinding load, the axis of each of the two guides, and the forward / backward axis If the shaft center is arranged on one reference straight line, the rotation axis of the grinding spindle is difficult to tilt, and abnormal grinding of the grinding wheel and poor grinding can be prevented. In the grinding apparatus provided with a plurality of grinding means and grinding feed means, a plurality of holding tables are supported by the turntable, and each holding table moves to a position facing the grinding wheel by rotation of the turntable. The turntable functions as positioning means.

1: Grinding device 2: Holding table 20: Positioning means 21: Cover member 2a: Holding surface 3: Grinding means 30: Grinding spindle 300: Rotating shaft 300a: Center axis 31: Spindle holder 32 Grinding wheel 320: Grinding wheel 4: Grinding Feed means 40: guide 40a: shaft center 41: advance / retreat shaft 41a: shaft center 42: portal column 420: pillar portion 420a: centroid 421: connecting portion 400, 401: guide 400a, 401a: shaft center 520, 620: pillar Part 520a, 620a: Centroid 100: Grinding area 100a: Grinding area center 101: Grinding area 101a: Grinding area center 102: Grinding area 102a: Grinding area center 200, 201, 202, 203, 204: Reference straight line

Claims (4)

A rotatable holding table for holding a plate-like workpiece, a grinding means for grinding the plate-like workpiece held on the holding table, and a forward and backward movement in a grinding feed direction in which the grinding means approaches or separates from the holding table. Grinding holding means for positioning, and positioning means for positioning a plate-like workpiece held by the holding table at a position facing a grinding wheel arranged in an annular shape on a grinding wheel mounted on the grinding means, and the holding table In a grinding apparatus for infeed grinding the upper surface of the plate-like workpiece held by the grinding means,
The grinding means is composed of a grinding spindle having a rotating shaft on which a grinding wheel is mounted, and a spindle holder that supports the grinding spindle,
The grinding feed means is arranged in parallel to the grinding feed direction, guides the vertical movement of the spindle holder, and advances and retracts the spindle holder directed by the two guides in the grinding feed direction. It consists of advancing and retracting axes,
The grinding area where the grinding wheel comes into contact with the upper surface of the plate-like workpiece held by the holding table has an arc shape having the width of the grinding wheel in the radial direction of the grinding wheel around the axis of the rotating shaft. ,
When the grinding means feeds the grinding means at a predetermined speed and the grinding wheel presses the upper surface of the plate-like workpiece in the grinding region, the grinding means is positioned at the grinding position by the grinding load. Press the holding table,
In cross-section view,該研the centroid of the cutting area, and the respective axis of the two guide, the axis of該進Shisajiku is, one grinding device arranged to the reference straight line of.   The grinding apparatus according to claim 1, wherein an axis of the rotation shaft is arranged on the reference straight line. A portal column having the two guides and an advancing / retracting shaft for grinding and feeding the grinding means;
The portal column is composed of two column portions that respectively support the two guides, and a connecting portion that connects the two column portions,
The grinding apparatus according to claim 1 or 2, wherein a centroid of a cross section of the column portion is arranged on the reference straight line.   The grinding apparatus according to claim 3, wherein a midpoint of a straight line connecting the centroids of the column section cross section of each of the two column sections coincides with the axis of the advance / retreat axis.

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