JP2012020344A - Method for forming housing tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a housing tool, in which a circular concave part having correct depth can be formed.SOLUTION: The method for forming the housing tool having the circular concave part 15 and an annular convex part 17 for surrounding the circular concave part 15 comprises: a step of holding a disk-shaped member 11 on a chuck table 36; and a grinding step of abutting a grinding stone 24, which has the diameter almost equal to 1/2 of that of the disk-shaped member 11, on the center of the disk-shaped member 11 and on the inside of the outer periphery the disk-shaped member 11, and rotating the chuck table 36 and the grinding stone 24 to form the circular concave part 15 and the annular convex part 17 for surrounding the circular concave part 15 on the disk-shaped member 11. The position of the height of a machined area is detected by a first height-position detection means 44 as a first height position, and the position of the height of an outer peripheral area corresponding to the annular convex part 17 is detected by a second height-position detection means 46 as a second height position. When a value obtained by subtracting the first height position from the second height position reaches a predetermined value, the grinding work is completed.

Description

  The present invention relates to a method for forming a container having a circular concave part for accommodating a plate-like object and an annular convex part surrounding the circular concave part.

  For example, in a semiconductor device manufacturing process, a plurality of circuit elements such as ICs and optical devices are formed on a wafer such as silicon, GaAs, sapphire, and SiC to manufacture a device wafer. Thereafter, the back surface of the device wafer is ground and polished to a predetermined thickness, and then divided by a cutting device to manufacture individual semiconductor devices.

  In general, when a workpiece is ground and thinned to a predetermined thickness by a grinding apparatus, the grinding is performed while detecting the upper surface height of the chuck table holding the workpiece and the upper surface height of the workpiece. Then, when the difference between the upper surface height of the workpiece and the upper surface height of the chuck table reaches a predetermined value, the grinding is stopped, so that the workpiece is thinned to a desired thickness (for example, Japanese Patent Laid-Open No. 2005-2005 -244911).

  Japanese Patent Laid-Open No. 2007-19461 discloses a wafer having a circular concave portion and an annular convex portion surrounding the circular concave portion. However, a circular concave portion is formed by grinding a disk-shaped member made of glass, silicon, or the like. And a circular convex portion surrounding the circular concave portion, and a plate-like object such as a semiconductor wafer may be used as a container for accommodating the circular concave portion.

  When grinding a workpiece to form a circular concave portion and an annular convex portion surrounding the circular concave portion, grinding is usually performed while detecting the top surface height of the chuck table and the bottom surface height of the circular concave portion. Grinding is stopped when the difference between the bottom surface height of the chuck and the top surface height of the chuck table reaches a predetermined value.

JP 2005-246491 A JP 2007-19461 A

  However, when using a disk-shaped member formed with a circular concave portion and an annular convex portion surrounding the circular concave portion as a container, it is necessary to accurately form the depth of the circular concave portion. When there is an error in the thickness of the disk-shaped member before grinding, if grinding is performed while detecting the bottom surface height of the circular recess and the top surface height of the chuck table, the depth of the circular recess to be formed is accurately set to the desired depth. There is a problem that it is not.

  This invention is made | formed in view of such a point, The place made into the objective is providing the formation method of the container which has a circular recessed part of exact desired depth.

  According to the present invention, there is provided a method for forming a container having a circular concave part and an annular convex part surrounding the circular concave part, and forming a container for accommodating a plate-like object in the circular concave part, the grinding apparatus A holding step for holding the disk-shaped member with the chuck table, and a disk-shaped member held by the chuck table with a grinding wheel having a diameter approximately half the diameter of the disk-shaped member. A grinding step for forming a circular concave portion in the disk-shaped member and forming an annular convex portion surrounding the circular concave portion by rotating the chuck table and the grinding wheel so as to contact the center and the front of the outer periphery In the grinding step, the first height position detecting means detects the height position of the processing region of the disk-shaped member corresponding to the circular recess as the first height position, and the second height. The disc shape corresponding to the annular convex portion by the position detecting means The height position of the outer peripheral area of the material is detected as the second height position, and grinding is performed while calculating a value obtained by subtracting the first height position from the second height position, and the second height position A method for forming a container is provided, in which grinding is terminated when a value obtained by subtracting the first height position reaches a predetermined value.

  According to the present invention, since grinding is performed while detecting the bottom surface height of the circular recess and the top surface height of the annular protrusion, the depth of the circular recess can be accurately formed to a desired depth.

It is a perspective view of a grinding device suitable for carrying out the forming method of the present invention. It is a perspective view of a disk-shaped member. It is a perspective view explaining the formation method of the container which concerns on this invention embodiment. It is a schematic diagram explaining the circular recessed part formation method. FIG. 5A is a cross-sectional view of the container according to the embodiment, and FIG. 5B is a cross-sectional view of a state in which the wafer is accommodated in a circular recess of the container.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic block diagram of a grinding apparatus 2 suitable for carrying out the present invention. Reference numeral 4 denotes a base (housing) of the grinding apparatus 2, and a column 6 is erected on the rear side of the base 4. A pair of guide rails 8 extending in the vertical direction are fixed to the column 6.

  A grinding unit (grinding means) 10 is mounted along the pair of guide rails 8 so as to be movable in the vertical direction. The grinding unit 10 includes a housing 12 and a support portion 14 that holds the housing 12, and the support portion 14 is attached to a moving base 16 that moves in the vertical direction along the pair of guide rails 8. .

  The grinding unit 10 includes a spindle 18 rotatably accommodated in a housing 12, a wheel mount 20 fixed to the tip of the spindle 18, and a plurality of grinding wheels 24 screwed to the wheel mount 20 and arranged annularly. And a servo motor 26 that rotationally drives the spindle 18.

  The grinding device 2 includes a grinding unit feed mechanism 32 that includes a ball screw 28 that moves the grinding unit 10 in the vertical direction along a pair of guide rails 8 and a pulse motor 30. When the pulse motor 30 is driven, the ball screw 28 rotates and the moving base 16 is moved in the vertical direction.

  A recess 4a is formed on the upper surface of the base 4, and a chuck table mechanism 34 is disposed in the recess 4a. The chuck table mechanism 34 has a chuck table 36 and is moved in the Y-axis direction between a wafer attachment / detachment position A shown in FIG. 1 and a grinding position B facing the grinding unit 10 by a moving mechanism (not shown). 38 and 40 are bellows. On the front side of the housing 4, an operation panel 42 on which an operator of the grinding device 2 inputs grinding conditions and the like is disposed.

  Referring to FIG. 2, a perspective view of a disk-shaped member 11 that is a processing target of the present invention is shown. The disk-shaped member 11 is composed of, for example, a silicon wafer sliced from a silicon ingot with a wire saw, and a notch 13 is formed on the outer periphery of the disk-shaped member 11 as a mark indicating the crystal orientation of the silicon wafer. ing.

  The disk-shaped member (silicon wafer) 11 has a thickness of about 700 μm, but the thickness is not uniform and has an error of about several tens of μm. The disk-shaped member 11 is not limited to a silicon wafer, and a glass plate or the like can be used.

  Next, with reference to FIG.1 and FIG.3, the formation method of the container which concerns on embodiment of this invention is demonstrated in detail. The silicon wafer 11 is sucked and held on the chuck table 36 positioned at the wafer attaching / detaching position A shown in FIG. Next, the chuck table 36 is moved in the Y-axis direction and positioned at the grinding position B.

  As shown in FIGS. 3 and 4, while rotating the chuck table 36 in the direction indicated by arrow a at 300 rpm, for example, the grinding wheel 24 is rotated in the direction indicated by arrow b at 6000 rpm, for example, and a grinding unit feed mechanism 32 is driven to bring the grinding wheel 24 of the grinding wheel 22 into contact with the back surface of the silicon wafer 11. Then, the grinding wheel 22 is ground and fed downward by a predetermined amount at a predetermined grinding feed speed.

  As a result of this grinding, as shown in FIGS. 3 and 5A, the silicon wafer 11 is formed with a circular recess 15 having a predetermined thickness at the center, and the circular recess 15 is formed on the outer periphery of the circular recess 15. A surrounding annular projection 17 is formed.

  During this grinding, the first height position detector 44 detects the height position of the processing region of the silicon wafer 11 corresponding to the circular recess 15 as the first height position, and the second height position detector 46 makes an annular shape. The height position of the outer peripheral area of the silicon wafer 11 corresponding to the convex portion 17 is detected as the second height position, and grinding is performed while calculating the value obtained by subtracting the first height position from the second height position. Then, control is performed so that the grinding is terminated when the value obtained by subtracting the first height position from the second height position reaches a predetermined value.

  Here, the relationship between the silicon wafer 11 held on the chuck table 36 and the grinding wheel 24 constituting the grinding wheel 22 will be described with reference to FIG. The rotation center P1 of the chuck table 36 and the rotation center P2 of the grinding wheel 24 are eccentric, and the outer diameter of the annular grinding wheel 24 is smaller than the diameter of the boundary line 19 between the circular concave portion 15 and the annular convex portion 17, The grinding wheel 24 that is set to a size larger than the radius of the boundary line 19 and arranged in an annular shape passes through the rotation center P <b> 1 of the chuck table 36.

  According to the storage portion forming method of the present embodiment, grinding is performed while detecting the bottom surface height of the circular concave portion 15 and the top surface height of the annular convex portion 17, so that the depth of the circular concave portion 15 is accurately set to a desired depth. Can be formed.

  In the circular recess 15 of the container 48 thus formed, as shown in FIG. 5B, for example, a semiconductor wafer having a plurality of devices on the front surface and the back surface ground to a predetermined thickness is formed. 21 is accommodated.

  Thus, in a state where the semiconductor wafer 21 is accommodated in the circular recess 15 of the accommodation tool 48, for example, the accommodation tool 48 is directly placed on a material mounting table of a microscope, and a pattern defect or the like of the semiconductor wafer 21 is observed with a microscope. It can be magnified and observed.

  Since the container 48 has the annular convex part 17 surrounding the circular concave part 15, sufficient strength can be ensured. Therefore, in a state where the plate-like object such as the semiconductor wafer 21 is accommodated in the circular recess 15 of the accommodation tool 48, the accommodation tool 48 can be stacked and stacked, and space saving can be achieved.

2 Grinding device 10 Grinding unit 11 Silicon wafer (disk-shaped member)
15 circular concave portion 17 annular convex portion 22 grinding wheel 24 grinding wheel 36 chuck table 48 container

Claims (2)

A method for forming a container having a circular concave part and an annular convex part surrounding the circular concave part, and forming a container for accommodating a plate-like object in the circular concave part,
A holding step for holding the disk-shaped member on the chuck table of the grinding device;
A grinding wheel having a diameter approximately half the diameter of the disk-shaped member is brought into contact with the disk-shaped member held by the chuck table in front of the center and the outer periphery of the disk-shaped member, A grinding step of rotating the grinding wheel to form a circular recess in the disk-like member and forming an annular protrusion surrounding the circular recess,
In the grinding step,
The first height position detecting means detects the height position of the processing region of the disk-shaped member corresponding to the circular concave portion as the first height position, and the second height position detecting means detects the height position of the circular convex portion. Detecting the height position of the corresponding outer peripheral region of the disk-shaped member as a second height position, performing grinding while calculating a value obtained by subtracting the first height position from the second height position;
A method for forming a container, wherein the grinding is terminated when a value obtained by subtracting the first height position from the second height position reaches a predetermined value.   The container-forming method according to claim 1, wherein the disk-shaped member is made of silicon or glass.

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