JPH1055986A - Grooving method and grooving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize accurate grooving by combining a measuring device for measuring a height of the upper surface of a work with a grinder using a grinding stone blade. SOLUTION: In such a state that a work 2 of 4-inch silicon wafer with a thickness of 1mm is set to a chuck 1 having the upper surface inclined 8 degrees against the horizontal surface, the change in height of the upper surface of the work 2 is measured by a contact type shape measuring device 3. Then the device 3 is combined attachably and detachably to a grinder having such a structure comprised of a grind stone blade 6 which rotates at a high speed and grooves the upper surface of the work 2 at constant depth and width. Thus, the change in depth of groove from the upper surface thereof can be kept within a range of ±0.3μm accurately in the entire parts of the work 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method and a processing apparatus for forming a groove such as a V-groove in a work such as a silicon wafer used for an optical fiber array or the like. In detail, the method and the apparatus of the present invention combine a measuring machine that measures the height of the upper surface of a work that operates in a vertical direction in a grinding process using a grindstone blade, thereby realizing high-precision machining. It enables technology.

[0002]

2. Description of the Related Art When a large number of grooving processes are performed on the entire area of a work, there are various factors such as a shape error on a chuck upper surface, a non-uniform thickness of the work over the entire area of the work, and adhesion of foreign matter when setting the work on the chuck. The height of the work upper surface is not strictly horizontal. Therefore, even if grooving is performed with the height of the spindle to which the grindstone blade is attached being fixed, the depth of the processed groove from the upper surface of the work is not constant over the entire area of the work.

Further, when a large number of parts are produced by forming the work into chips, parts having different machining groove depths depending on the partial height variation of the work are produced, which is a factor that lowers the yield rate. Had become.

[0004]

As described in the prior art, in the work grooving method in which the height of the spindle is constant, the shape accuracy of the chuck for setting the work and the uniformity of the work thickness over the whole area of the work are considered. Must be strictly managed. However, not only is it difficult to control them, but when considering the non-defective rate of the work thickness and grooving the work, and considering the non-defective rate of the chipped parts, the productivity is poor and the non-defective rate decreases. There was a problem to do.

When a workpiece is set on a chuck whose upper surface is substantially horizontal, and the spindle is moved in both vertical directions (Z-axis direction) during machining so as to follow the height fluctuation of the upper surface of the workpiece, Poor positioning accuracy due to backlash in the vertical movement of the spindle in the Z-axis direction on the slide surface with the device body, and change in the attitude of the spindle, etc., and follows the fluctuation of the height of the upper surface of the workpiece in the spindle Z-axis direction. There was a problem that accuracy deteriorated.

[0006]

As a result of various studies on the above problems, the present inventor has found that grooving can be performed by combining a grinding machine using a grindstone blade with a measuring machine for measuring the height of the work upper surface. Can be performed with high accuracy,
The present inventors have found that the yield rate of work parts formed into chips can be increased, and have completed the present invention. That is,
The present invention provides a grinding method for grooving a work such as a silicon wafer by rotating a grindstone blade at a high speed. The depth of the machining groove from the upper surface of the work is almost constant over the entire area of the work by measuring the height of the work in advance and correcting the partial fluctuation of the height of the upper surface of the work to the vertical movement of the spindle during machining. And a grooving method. Also,

Another feature is that the inclination angle of the chuck with respect to the horizontal plane is 30 ° or less. Another characteristic is that the measuring machine for measuring the height of the upper surface of the work is detachable from the processing machine. Also, a grooving machine, which measures the height of the upper surface of the work, is detachably combined with a grinding machine consisting of a grindstone blade that grooves the upper surface of the work at a certain depth and width by rotating at a high speed. Provide a processing device. Hereinafter, the present invention will be described in detail with reference to the drawings.

[0008]

According to the present invention, a large number of parts can be removed from a work at a high product rate without strictly controlling the shape accuracy of a chuck for setting a work such as a silicon wafer and the uniformity of the work thickness over the entire work area. To produce
(B) With the work set on the upper surface of the chuck inclined with respect to the horizontal plane, (b) The work top height is measured in advance on a processing machine, and partial fluctuations in the work top height are being processed. By correcting the vertical movement of the spindle, the depth of the machining groove from the upper surface of the work can be made substantially constant over the entire area of the work (claim 1).

Conventionally, if this correction operation is performed in both the up and down directions, an error will increase. However, if the chuck surface is provided with a certain inclination as in the present invention, even if the work surface undulates, the movement of the spindle is well corrected in one direction. It is enough. In this way, by inclining the chuck upper surface for setting the work with respect to the horizontal plane, the spindle is always moved downward in the Z-axis vertical direction without moving the spindle in both the vertical direction of the Z-axis so as to follow the height fluctuation of the work upper surface. Alternatively, the spindle can follow the fluctuation of the height of the upper surface of the work with high accuracy by only the upward movement in one direction. In this case, if the direction of the normal movement is changed, an error occurs in the movement. However, there is an advantage that the movement can be accurately performed if the movement is in one direction as in the present invention.

Further, the inclination angle of the upper surface of the chuck for setting the work with respect to the horizontal plane is 30 ° or less, preferably 1 °.
By setting the angle to 0 ° or less, more preferably 5 ° to 8 °, the positioning of the stage to which the chuck is attached in the movement direction (X-axis direction) is more than the target value of the depth of the machining groove when the position is shifted from the commanded position. Can be reduced (claim 2).

In addition, the measuring machine for measuring the height of the upper surface of the work is detachable from the processing machine, so that the measuring machine is detached from the processing machine at the time of processing, so that the measuring machine can be ground. Since it is not exposed to liquid, grinding debris, etc., it is possible to prevent deterioration of measurement accuracy and deterioration of the measuring device itself (claim 3). The processing apparatus of the present invention is characterized in that (a) a measuring machine for measuring the height of the upper surface of a work, (b) grinding of a structure made of a grindstone blade that grooves the upper surface of the work at a constant depth and width by rotating at a high speed. It is characterized in that it is detachably combined with the processing device (claim 4).

[0012]

The present invention will be described in detail with reference to the following examples, which do not limit the scope of the present invention.
1 and 2 are schematic views illustrating an embodiment of a grooving method and a processing apparatus according to the present invention. FIG. 1 shows a state when the surface height of the work is measured. FIG. 2 shows a state at the time of grooving.

1 and 2, 1 is a chuck, 2 is a work, 3 is a work upper surface height measuring machine, 4 is an inclination angle, 5 is a stage, and 6 is a grindstone blade. As shown in FIGS. 1 and 2, a chuck 1 having an upper surface inclined by 8 ° with respect to a horizontal plane.
And a 1-mm thick 4-inch silicon wafer (work) 2
, The height variation of the upper surface of the work was measured by a contact type shape measuring device (a long range contact type displacement meter manufactured by Keyence Corporation) 3.

The data sampling interval for measuring the height of the upper surface of the work over the entire region was 5 mm for both the stage movement direction (X axis) and the machining groove pitch direction (Y axis). After the measurement, the contact type shape measuring machine 3 is removed from the grooving machine 8 and the spindle 6 is processed during machining of the workpiece upper surface height direction (Z axis) data at each (X, Y) coordinate value.
The vertical movement of the machining groove from the top surface of the work
High-precision grooving of 0.3 μm was realized. In addition, as a result of producing a large number of parts by further dividing the wafer work 2 into chips, a good value of 90% or more was obtained.

[0015]

As described above, in the present invention, the height of the upper surface of the work is measured on the machine in advance with the work set on the upper surface of the chuck inclined with respect to the horizontal plane.
By correcting the partial fluctuation of the height of the upper surface of the work to the vertical movement of the spindle during the grooving, the depth of the processing groove from the upper surface of the work can be processed uniformly over the entire area of the work. Because of the shape of the chuck,
A large number of parts can be produced from a work at a high yield rate without strictly controlling the accuracy or the uniformity of the thickness of the work over the entire area of the work.

[Brief description of the drawings]

FIG. 1 is a schematic view for explaining an embodiment of a grooving method and a processing apparatus according to the present invention, and shows a state when a surface height of a work is measured.

FIG. 2 is a schematic view illustrating an embodiment of a grooving method and a processing apparatus according to the present invention, and FIG. 2 shows a state at the time of grooving.

[Explanation of symbols]

 Reference Signs List 1 chuck 2 work 3 work top surface height measuring device 4 inclination angle 5 stage 6 grinding wheel blade

Claims (4)

[Claims] In a grinding method for grooving a work such as a silicon wafer by rotating a grindstone blade at a high speed, the work is set on an upper surface of a chuck inclined with respect to a horizontal plane. By measuring the height in advance with a measuring machine and correcting the partial variation in the height of the upper surface of the work to the vertical movement of the spindle during machining, the depth of the machining groove from the upper surface of the work over the entire area of the work is almost A grooving method characterized by constant processing. 2. The grooving method according to claim 1, wherein an inclination angle of the chuck with respect to a horizontal plane is 30 ° or less. 3. The method according to claim 1, wherein the measuring device for measuring the height of the upper surface of the work is detachable from the processing machine.
The grooving method described. 4. A measuring machine for measuring the height of a work upper surface,
A grooving apparatus characterized in that it is detachably combined with a grinding machine comprising a grindstone blade for grooving a work surface at a constant depth and width by rotating at a high speed.