JP5912443B2 - Tool cutting tool - Google Patents

Description

  According to the present invention, a workpiece having a first region having a first thickness and a second region having a second thickness on a surface is cut by a cutting tool unit to form the workpiece to a predetermined thickness. The present invention relates to a tool cutting method for a workpiece.

  In a cutting tool such as that described in JP-A-2009-172723, the workpiece and the cutting tool are relatively moved in the horizontal direction while rotating the cutting tool positioned at a predetermined height. Cutting with a bite tool.

  Examples of the workpiece to be cut by such a cutting tool include a semiconductor wafer having a plurality of bumps formed on the device surface. Such a bump is formed by a method such as plating or stud bump.

  For this reason, the height of each bump is non-uniform, and it is difficult to uniformly bond a plurality of bumps to all the electrodes of the wiring board as it is, so cut the bumps together with the sealing resin with a cutting tool. The bumps are evenly arranged.

  Other workpieces suitable for cutting with a cutting tool include a workpiece having a first region having a first thickness and a second region having a second thickness on the surface. As an example of such a workpiece, there is a workpiece in which a resist film is coated on the surface as a through electrode forming pattern and a through electrode of a predetermined depth is embedded inside, compared to the upper surface of the resist film. The upper surface of the through electrode is formed at a low position.

JP 2009-172723 A

  A workpiece having a first region having a first thickness on the surface and a second region having a second thickness larger than the first thickness is cut with a cutting tool, and the predetermined thickness is determined from the first thickness. When trying to form a work piece with reduced thickness, the cutting tool will be deeply cut in the second area, and the quality of the surface to be cut will deteriorate, and the cutting edge of the cutting tool will be abnormally worn or chipped. There is a fear.

  The present invention has been made in view of such points, and the object of the present invention is to prevent the cutting tool from being excessively cut for each workpiece and to deteriorate the quality of the surface to be cut of the workpiece. It is another object of the present invention to provide a method of cutting a workpiece that prevents chipping or abnormal wear that occurs in a tool or a cutting tool.

According to the present invention, the surface side of a workpiece having a first region having a first thickness and a second region having a second thickness larger than the first thickness on the surface is cut by a cutting tool. A workpiece cutting method for forming a workpiece to a thickness obtained by subtracting a predetermined thickness from the first thickness, wherein a back surface side of the workpiece is a chuck table having a holding surface for holding the workpiece. Holding the step to expose the surface of the workpiece, and after performing the holding step, the upper surface height position of the first region and the upper surface of the second region of the workpiece held by the chuck table A height position detecting step for detecting the height position at a plurality of points, and a height position detecting step from the highest position among the upper surface height positions of the plurality of second regions detected in the height position detecting step. The upper surfaces of the plurality of first regions detected by A thickness calculating step for calculating a value obtained by subtracting the lowest position among the height positions as an excess thickness, and a maximum cutting amount that the cutting tool can cut into the workpiece by one rotation after the thickness calculating step is performed. And a cutting frequency calculation step for calculating the number of cuttings required to remove the excessive thickness from the excessive thickness, and after performing the cutting frequency calculation step, the cutting frequency calculated in the cutting frequency calculation step Based on the surplus thickness removing step of removing the surplus thickness by moving the chuck table while operating the cutting tool on the surplus removing cutting condition, the surplus thickness removing step is followed by the surplus thickness removing step. conditions cutting different workpiece while operating the byte cutting means in cutting cutting conditions by machining feed the chuck table workpiece and, said the outermost low position And a workpiece cutting step of forming a workpiece thickness obtained by subtracting the Teiatsumi, byte cutting method of the workpiece, characterized by comprising a are provided.

  In the workpiece cutting method of the present invention, the surplus thickness is calculated from the highest position of the second region and the lowest position of the first region. Then, the number of cuttings is calculated from the maximum cutting amount that can be cut into the workpiece by one rotation of the cutting tool and the surplus thickness, and the surplus thickness is cut by the number of times of cutting calculated by the surplus removal cutting conditions. After cutting off the workpiece, the workpiece is cut under the cutting conditions for cutting the workpiece. Therefore, the cutting tool is prevented from being excessively cut into the workpiece, and the quality of the cutting surface of the workpiece is deteriorated or the cutting tool is cut. Can prevent chipping and abnormal wear.

1 is an overall perspective view of a cutting tool suitable for carrying out the cutting method of the present invention. It is a perspective view of a cutting feed unit. It is a longitudinal cross-sectional view of an example of a to-be-processed object. It is a partial cross section side view which shows a holding | maintenance step. It is a partial cross section side view which shows a height position detection step. It is a partial cross section side view which shows a thickness calculation step. It is an expanded sectional view showing the number of times of cutting calculation step. It is sectional drawing of the to-be-processed object after a surplus thickness cutting step. It is sectional drawing explaining a workpiece cutting step. It is a partial cross section side view which shows the height position detection step of 2nd Embodiment. It is a partial cross section side view explaining the predetermined thickness calculation step of 2nd Embodiment. It is a schematic diagram which shows the cutting step of a workpiece.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a cutting tool 2 suitable for carrying out the cutting method for a workpiece according to the present invention. Reference numeral 4 denotes a base of the cutting tool 2, and a column 6 is erected on the rear side of the base 4. A pair of guide rails (only one is shown) 8 extending in the vertical direction is fixed to the column 6.

  A cutting tool unit 10 is mounted along the pair of guide rails 8 so as to be movable in the vertical direction. The cutting tool unit 10 is attached to a moving base 12 whose housing 20 moves in the vertical direction along a pair of guide rails 8.

  The cutting tool unit 10 is detachably mounted on a housing 20, a spindle 22 (see FIG. 12) rotatably accommodated in the housing 20, a mount 24 fixed to the tip of the spindle 22, and the mount 24. And a bite wheel 25. A bite tool 26 is detachably attached to the bite wheel 25.

  The cutting tool unit 10 includes a cutting tool feed mechanism (cutting means) 18 composed of a ball screw 14 and a pulse motor 16 that move the cutting tool unit 10 in a vertical direction along a pair of guide rails 8. . When the pulse motor 16 is pulse-driven, the ball screw 14 rotates and the moving base 12 is moved in the vertical direction.

  A chuck table mechanism 28 is disposed at an intermediate portion of the base 4. As shown in FIG. 2, the chuck table mechanism 28 includes a support base 30 and a chuck table 32 that is rotatably disposed on the support base 30. The chuck table mechanism 28 further includes a water cover 34.

  The chuck table 32 is reciprocated in the Y-axis direction in FIG. 1 by a cutting feed mechanism (cutting feed means) 36. The cutting feed mechanism 36 includes a ball screw 38 and a pulse motor 42 connected to one end of a screw shaft 40 of the ball screw 38.

  When the pulse motor 42 is pulse-driven, the screw shaft 40 of the ball screw 38 is rotated, and the support base 30 having a nut (not shown) screwed to the screw shaft 40 is guided by the pair of guide rails 44 to be cut by the cutting device 2. Move in the Y-axis direction (front-rear direction).

  Therefore, the chuck table 32 also moves in the front-rear direction according to the rotation direction of the pulse motor 42. As shown in FIG. 1, the pair of guide rails 44 and the cutting feed mechanism 36 shown in FIG. 2 are covered with a bellows 33.

  Referring again to FIG. 1, a gate-shaped attachment member 46 is fixed to the upper surface of the base 4 so as to cross the base 4. Two height measuring devices 48 and 50 are mounted on the attachment member 46.

  The height measuring instruments 48 and 50 are preferably non-contact measuring instruments such as ultrasonic measuring instruments. In this embodiment, two height measuring devices 48 and 50 are used, but only one height position measuring device may be provided.

  The front portion of the base 4 includes a first wafer cassette 52, a second wafer cassette 54, a wafer transfer robot 56, a positioning mechanism 58 having a plurality of positioning pins 60, and a wafer carry-in mechanism (loading arm) 62. Also, a wafer carry-out mechanism (unloading arm) 64 and a spinner cleaning unit 66 are provided.

  Next, with reference to FIG. 3 thru | or FIG. 12, the cutting tool cutting method of the workpiece which concerns on embodiment of this invention is demonstrated. Referring to FIG. 3, a cross-sectional view of a workpiece 11 suitable for cutting with the cutting tool method of the present invention is shown.

  The workpiece 11 includes a semiconductor wafer 13. A plurality of devices 15 are formed on the surface of the semiconductor wafer 13, and a resist film 19 is coated as a through electrode forming pattern. A plurality of through holes are formed in the resist film 19 corresponding to each device 15 by pattern exposure and development, and a through electrode (copper post) 17 is embedded in each through hole.

  The height of the upper surface of the through electrode 17 is formed lower than the height of the upper surface of the resist film 19. That is, the workpiece 11 has a first region 17a having a first thickness and a second region 19a having a second thickness larger than the first thickness on the surface thereof.

  In the cutting method for the workpiece 11 of this embodiment, first, as shown in FIG. 4, the back surface side of the workpiece 11 is sucked and held by the holding surface 32 a of the chuck table 32 to expose the surface of the workpiece 11. The holding step is performed.

  After performing the holding step, as shown in FIG. 5, the upper surface height position of the first region 17a and the upper surface height position of the second region 19a of the workpiece 11 held by the chuck table 32 are set to a height. By moving the measuring instruments 48 and 50 in the horizontal direction (X-axis direction), a height position detecting step for detecting at a plurality of points is performed.

  In the present embodiment, in order to speed up the detection of the height position, the height measuring device 48 measures the height position on the right side from the center of the workpiece 11, and the height measuring device 50 measures the height on the left side from the center. The position is being measured.

  The method of detecting the height position is not limited to this. For example, the height measuring device 48 measures the height position of the first region 17a, and the height measuring device 50 determines the height position of the second region 19a. You may make it measure.

  Next, as shown in FIG. 6, the plurality of first regions 17a detected in the height position detecting step from the highest position h1 among the upper surface height positions of the plurality of second regions 19a detected in the height position detecting step. A value obtained by subtracting the lowest position h2 of the upper surface height positions is calculated as the surplus thickness t1 (thickness calculation step).

  After performing the thickness calculation step, as shown in FIG. 7, the surplus thickness t1 is removed from the maximum cut amount h and the surplus thickness t1 that the cutting tool unit 10 can cut into the workpiece by one rotation. A necessary number of times of cutting N is calculated (number of times of cutting calculation step). That is, the number of times of cutting N is calculated by dividing the surplus thickness t1 by the maximum cutting depth h.

  After performing the cutting frequency calculation step, the surplus thickness cutting step of removing the excessive thickness t1 is performed by operating the cutting tool unit 10 under the excessive removal cutting conditions by the cutting frequency N calculated in the cutting frequency calculation step.

  In this surplus thickness cutting step, as shown in FIG. 12, while the spindle 22 is rotated at about 2000 rpm, the cutting tool feeding mechanism 18 is driven to cut the cutting blade 26a of the cutting tool 26 into the workpiece 11 to the maximum cut amount. Cut with h.

  Then, the workpiece 11 is cut while moving the chuck table 32 in the arrow Y direction at a feed rate of 1 mm / s, for example. At the time of this cutting process, the chuck table 32 is processed and fed in the Y-axis direction without rotating.

  When one cutting process is completed, the chuck table 32 is moved in the Y-axis direction to return to the original position, and the cutting with the maximum cutting amount h is repeated N-1 times. The last cutting process is less than the maximum cutting depth h. The excess thickness t1 is removed by cutting with the cut amount. The workpiece 11 after completion of the excess thickness removal step is shown in FIG.

  After performing the excess thickness removing step, as shown in FIG. 9, the workpiece 11 is cut by operating the cutting tool unit 10 under the cutting conditions for cutting the workpiece, and the workpiece 11 is predetermined from the lowest position h2. A workpiece cutting step is performed to form a thickness reduced by thickness t2.

  This workpiece cutting step is performed in the same manner as the excess thickness removing step described with reference to FIG. The cutting conditions for cutting the workpiece may be the same as the cutting conditions for excess removal, or may be different cutting conditions. When the predetermined thickness t2 is thicker than the maximum cutting amount h, the workpiece 11 is cut a plurality of times.

  In both the excess thickness removing step and the workpiece cutting step, the remainder of the number of cuttings may be processed either at the beginning, in the middle, or at the end. In the final cutting step, it is preferable to slow down the feed speed of the chuck table 32.

  Next, a cutting tool cutting method for a workpiece according to a second embodiment of the present invention in which the workpiece 11 is formed to a finished thickness by controlling the amount of uncut will be described with reference to FIGS. In the height position detection step of the present embodiment, as shown in FIG. 10, the height measuring device 48 detects the height position of the holding surface 32 a of the chuck table 32.

  Then, the height position of the workpiece 11 is measured at a plurality of points while moving the height measuring device 50 along the workpiece 11, and the highest position h1 and the lowest position h2 of the workpiece 11 are detected.

  Next, as shown in FIG. 11, a value obtained by subtracting the lowest position h2 from the highest position h1 is calculated as the surplus thickness t1, and a value obtained by subtracting the finishing thickness t3 from the measured lowest position h2 is calculated as the predetermined thickness t2.

  Then, similarly to the first embodiment described above in the surplus thickness removing step, the cutting tool unit 10 is operated a plurality of times to remove the surplus thickness t1, and the workpiece 11 is cut by the predetermined thickness t2 in the workpiece cutting step. The workpiece 11 is finished to a finished thickness t3.

  In the workpiece cutting method of the workpiece described above, the surplus thickness t1 is calculated from the highest position h1 of the second region 19a of the workpiece 11 and the lowest position h2 of the first region 17a. After the cutting tool N is calculated from the maximum cutting amount h1 that can be cut into the workpiece 11 by one rotation and the surplus thickness t1, the surplus thickness t1 is removed by cutting under surplus removal cutting conditions. Since the workpiece 11 is cut under the cutting conditions for cutting the workpiece, the cutting tool 26 is prevented from being excessively cut into the workpiece 11, and the quality of the cutting surface of the workpiece 11 is deteriorated or the cutting tool 26 is cut. Can prevent chipping and abnormal wear.

2 cutting tool 10 cutting tool unit 11 workpiece 13 semiconductor wafer 15 device 17 copper post 17a first area 18 cutting tool feed mechanism 19 resist 19a second area 32 chuck tables 48, 50 Height measuring device

Claims (1)

The surface side of a workpiece having a first region having a first thickness on the surface and a second region having a second thickness greater than the first thickness is cut by a cutting tool, and the first A workpiece cutting method for forming a workpiece to a thickness obtained by subtracting a predetermined thickness from the thickness of the workpiece,
A holding step of holding the back side of the workpiece with a chuck table having a holding surface for holding the workpiece and exposing the surface of the workpiece;
After performing the holding step, height position detection for detecting the upper surface height position of the first area and the upper surface height position of the second area of the workpiece held by the chuck table at a plurality of points, respectively. Steps,
The lowest of the upper surface height positions of the plurality of first regions detected in the height position detection step from the highest position among the upper surface height positions of the plurality of second regions detected in the height position detection step. A thickness calculating step for calculating a value obtained by subtracting the position as an excess thickness;
After performing the thickness calculating step, the number of times of cutting necessary to remove the excess thickness is calculated from the maximum cutting amount that the cutting tool can cut into the workpiece with one rotation and the excess thickness. Cutting number calculation step,
After performing the cutting number calculation step, the chuck table is processed and fed while operating the cutting tool under cutting conditions for excessive removal based on the cutting number calculated in the cutting number calculation step, and the excess thickness is calculated. Excess thickness removal step to remove;
Subsequent to the excess thickness removing step , the workpiece is cut by feeding the chuck table while operating the cutting tool under cutting conditions for cutting the workpiece different from the cutting conditions for removing excess , and cutting the workpiece. A workpiece cutting step for forming the workpiece to a thickness obtained by subtracting the predetermined thickness from the lowest position;
A workpiece cutting method for a workpiece characterized by comprising:

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