JPH04280630A - Inner slice blade fixing mechanism for slicer - Google Patents

Abstract

PURPOSE:To provide the title inner slice blade fixing mechanism for a slicer capable of eliminating the deviation in the tension due to the scratch, deformation and detrioration in flatness of a press ring. CONSTITUTION:The title inner slice blade fixing step is made feasible with high precision by several methods mentioned as follows, i.e., the mechanical strength of the abutting part of a fixing bolt 28 of a press ring 26 is increased by enlarging the sectional shape of the abutting part; a scratch preventive member 27 is interposed between the bolt 28 and the press ring 26; and automatic alignment means is used between said bolt 28 and said member 27 or between the bolt 28 and the press ring 26 to avoid the positional slip or the scratch thereby avoiding the minor deformation of the press ring 26; and the tightening forces for the press ring 26 are equalized.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION This invention relates to an improvement in the tensioning mechanism of the inner peripheral blade of a slicing device for cutting wafers from semiconductor ingots. By preventing the press ring from shifting or being damaged when the bolt comes into contact, it suppresses uneven tension applied to the inner blade due to slight deformation of the press ring, making it possible to tension the inner blade with high precision. This invention relates to an inner peripheral blade tensioning mechanism of a slicing device.

0002

[Prior Art] A cutting machine device for cutting out extremely thin silicon wafers from hard and brittle silicon ingots is shown in Fig. 1.
As shown in FIG. 2, an inner peripheral blade 1 has diamond abrasive grains 2 electrodeposited on the inner peripheral edge of an annular metal disk having a required inner diameter.
A slicing device that is attached to a rotary chuck 10 and rotated to cut a wafer of a desired thickness from a silicon ingot 3 is often used.

The silicon ingot 3 is attached to an adhesive block 4 on an indexer 5 placed on a feed table 6 that is horizontally movable at a required speed and on a base 7 that pivotally supports a rotary chuck 10 that is rotationally driven by an electric motor 8. is anchored through the perpendicular,
The inner peripheral blade 1, which is moved in the vertical direction by the electric motor for the indexer 5 and rotated by the movement of the feed table 6, slices into the required thickness.

[0004] What is important in terms of the quality of semiconductor wafers is the tension of the inner peripheral grindstone. If the tension is insufficient, the cut wafer will tend to warp and ridge, and the thickness will vary widely, causing the wafer to be partially chipped,
Cracks may occur.

As shown in FIGS. 13 and 14, the inner blade tensioning mechanism for applying the required tension to the inner blade of the slicing device includes an inner blade 1 on the upper circumferential end surface of the bottom portion 11 of the chuck 10. The top ring 13 is screwed in with the bolt 15 to hold the inner peripheral blade 1, and a plurality of tensioning bolts 17 screwed into the top ring 13 are moved back and forth to be built into the circumferential groove 14. The press ring 16 is brought into contact with the inner circumferential cutter 1 located on the groove 12 provided on the upper circumferential end surface of the bottom portion 11 to apply tension to the entire inner circumferential cutter 1.

As shown in FIG. 15, the tensioning bolts 17 are arranged so as to abut on a required circumference of the outer circumference of the inner peripheral blade 1 at regular intervals.

[Problem to be solved by the invention]

In such an inner peripheral blade tensioning mechanism, when the tensioning bolt 17 is screwed together, the press ring 16 presses against the inner peripheral blade 1 material and applies tension to the entire inner peripheral blade 1. Although it has the advantage of improving roundness, bolt 1
7 is further screwed together, a slight stress strain is generated in the press ring 16 depending on whether or not the bolt 17 is in contact with the press ring 16, and the flatness of the press ring 16 deteriorates, albeit slightly.

[0008] As the flatness of the press ring deteriorates, the inner peripheral blade itself vibrates slightly during rotation, and the vibration resonates, increasing the runout of the inner peripheral blade, increasing the machining allowance during machining, and causing ridges. This problem occurs when the inner blade material and the material to be cut come into contact with each other, or it affects the flow of chips between the inner peripheral blade material and the material to be cut during machining, increasing cutting resistance and causing deformation of the cutting edge. There is.

[0009] When the wafer is cut out with the flatness of the press ring deteriorated, the quality, processing accuracy such as flatness, and surface roughness deteriorate, and the stability of the inner peripheral blade itself deteriorates.
Wafers tend to warp. In addition, there was a problem in that the difference in tension created a part that was prone to buckling as the number of cuts was increased, and if cutting continued as it was, the amount of surface runout of the inner peripheral blade would increase, which would have a negative effect on cutting. .

On the other hand, in order to prevent the flatness of the inner peripheral blade from deteriorating, techniques have been proposed in which the inner diameter of the inner peripheral blade is changed from a perfect circle to an ellipse, and the width of the electrodeposition of diamond abrasive grains is changed into an elliptical shape. ing.

[0011] Such a proposal can deal with the problems that vary depending on the rolled material due to the anisotropy of the thin stainless steel sheet that is the material for the inner peripheral blade and the difference in elongation between the rolling direction and the direction perpendicular to rolling. There is no improvement in the above-mentioned problem of tension variation due to deformation of the press ring and deterioration of flatness.

Furthermore, the tensioning bolts that come into contact with the press ring are generally rod-pointed or flat-pointed bolts, and there is a gap between the bolt hole and the thread pitch, which causes the bolt to tilt slightly when tightened. There is a problem in that the press ring is easily scratched, and the scratches cause a difference in strength in the circumferential direction of the press ring, resulting in uneven tension in the inner peripheral blade.

[0013] The present invention has been developed in view of the current situation regarding the inner peripheral blade tensioning mechanism of a slicing device.
The purpose is to provide a tensioning mechanism that can eliminate variations in tension caused by deterioration in flatness.

[0014]

[Means for Solving the Problems] This invention holds the inner peripheral blade by placing the outer peripheral part of the inner peripheral blade on the upper circumferential end surface of the bottom part of the chuck, and screwing the top ring onto the top ring. In the inner peripheral blade tensioning mechanism of a slicing device that applies tension to the inner peripheral blade by bringing the built-in press ring into contact with the outer peripheral part of the inner peripheral blade by advancing and retracting the mating bolt, the tensioning bolt of the press ring contacts the part of the inner peripheral blade. This is an inner peripheral blade tensioning mechanism for a slicing device characterized by a ring cross-sectional shape that is larger than other parts. Furthermore, in the inner peripheral blade tensioning mechanism of such a slicing device, a scratch-preventing member is interposed at least in the portion where the tensioning bolt of the press ring comes into contact, or furthermore, a scratch-preventing member is provided between the tip of the tensioning bolt and a scratch-preventing member. This is an inner peripheral blade tensioning mechanism for a slicing device characterized by using automatic centering means in the upper surface shape of the member. The present invention also provides an inner peripheral blade tensioning mechanism for a slicing device characterized in that a self-aligning means is used for the tensioning bolt tip and the top surface shape of the press ring.

[0015]

[Operation] This invention is a slicing device that has a chuck on the upper circumferential end surface of the bottom portion that holds the inner peripheral blade between top rings. In a mechanical inner peripheral blade tensioning mechanism that applies tension by contacting the outer peripheral part, the mechanical strength of the part where the tensioning bolt of the press ring contacts is improved by increasing the cross-sectional shape of the part,
In addition, by interposing a scratch prevention member between the tensioning bolt and the press ring, or by using self-aligning means between the bolt and the scratch prevention member or between the bolt and the press ring, when the bolt is brought into contact, By preventing the press ring from being misaligned or scratched, it prevents slight deformation of the press ring and equalizes the tightening force applied to the press ring by the tensioning bolt, allowing for high-precision tensioning of the inner peripheral edge. made possible.

In this invention, the method of enlarging the cross-sectional shape of the part of the press ring that the tensioning bolt contacts is to increase the ring width or increase the ring height, if the mechanical strength of the part can be improved. Measures such as doing this can be adopted.

In this invention, the scratch-preventing member interposed between the tensioning bolt and the press ring can be, for example, a thin plate piece or a thin plate ring, or it can be embedded or the press ring can be divided into two parts. It is also preferable to use the upper side as a scratch-preventing member, and by replacing this member if it gets scratched, highly accurate tensioning of the inner peripheral blade can be maintained, and furthermore, an automatic centering means described later can be used.

In the present invention, the self-aligning means provided between the tensioning bolt and the scratch-preventing member or between the bolt and the press ring is simply provided with a shape that fits between the two, thereby preventing the inclination of the bolt. Any known configuration can be selected as appropriate, from a configuration that reduces the influence of processing accuracy at the tip to a mechanism that actively centers the tip using a spherical seat and a spherical surface, or a conical seat and a conical shape.

[0019]

[Example] Example 1 In a mechanism that applies tension to the inner peripheral blade by bringing a tensioning bolt into contact with a press ring, the deformation of the inner peripheral blade was investigated by the deformation rate depending on the positional relationship of the tensioning bolt. When the conventional press ring 16 having a uniform cross-sectional shape as shown in FIG. The press ring 20 according to the present invention shown in FIG. 4 has a structure in which the height of the position where the tensioning bolt 17 comes into contact is increased, but when similarly examined by the deformation rate, the deformation pattern shown by curve B in FIG. 5 was found. Ta. In a mechanism that applies tension to the inner blade by bringing tensioning bolts into contact with the press ring, the amount of deformation due to bending of the press ring depends on the relationship between the section modulus of the cross-sectional shape and the arbitrary amount of deflection of the beam. Since the force that presses the press ring appears as a reaction of the inner circumferential cutter pushing the press ring, it can be seen that deformation of the press ring can be suppressed by increasing the cross-sectional shape at the contact point of the press ring with the bolt.

Embodiment 2 A press ring 21 according to the present invention shown in FIG. 1 has a structure in which the thickness of the ring at the position where the tensioning bolt abuts is expanded outward in the radial direction to enlarge the cross-sectional shape. When the deformation of the inner circumferential cutter when using the press ring 21 according to the present invention was investigated by the deformation rate depending on the positional relationship of the tensioning bolt, the deformation pattern was shown by curve C in Fig. 5, and the curve in the case of the conventional press ring was found. It can be seen that the deformation of the press ring can be suppressed compared to the deformation pattern A.

Embodiment 3 In the press ring 22 according to the present invention shown in FIG. 2, the ring thickness at the position where the tensioning bolt contacts is expanded outward and inward in the radial direction, and the height at the position is expanded upward. It consists of a structure with a larger cross-sectional shape. When the deformation of the inner circumferential cutter when using the press ring 22 according to the present invention was investigated by the deformation rate in relation to the positional relationship of the tensioning bolt, the deformation pattern was shown by curve D in Fig. 5, and the curve in the case of the conventional press ring was found. It can be seen that the deformation of the press ring can be significantly suppressed compared to the deformation pattern A.

Example 4 Press ring 22 according to the invention shown in FIG. 2 of Example 3
, and a conventional press ring 16 with a uniform cross-sectional shape shown in FIG. 3, the stress distribution in the circumferential direction and the radial direction of the inner peripheral blade was investigated. As the measurement results are shown in FIG. 6, in the case of the conventional press ring 16, the relationship between the cross-sectional shape and the stress distribution in the circumferential direction and the radial direction is a pattern of curves E and H, and the maximum At the deformation point, the pattern was curves G and J. On the other hand, the press ring 22 according to the present invention has a pattern of curves F and I in FIG.
It can be seen that the difference in stress is small.

Embodiment 5 A tensioning mechanism according to the present invention shown in FIG. 7 uses a normal press ring 16 and has a structure in which a scratch prevention member 23 made of a thin plate ring is interposed between the tensioning bolt 25 and the tensioning bolt 25. Further, the tip of the tensioning bolt 25 is recessed into a spherical seat, and there is a self-aligning mechanism in which the hemispherical protrusion 24 protruding from the scratch-preventing member 23 can be engaged with the concave and convex portions.
Since the area of the contact surface of the tensioning bolt 25 is large and the surface precision is high, the pressing force during tightening acts uniformly through the scratch prevention member 23 to prevent slight deformation of the press ring 16. Can be done.

Embodiment 6 A tensioning mechanism according to the present invention shown in FIG. 8 uses a press ring 26 that is divided into two parts, the upper part being a scratch-preventing member 27. is formed with a groove having an arcuate cross section, and the tensioning bolt 28
The tip of the bolt is formed into a hemispherical protrusion 29 and has an uneven surface as a self-aligning mechanism, and the contact surface of the tensioning bolt 28 has a large area and high surface accuracy, so the pressing force when tightening is effective to prevent damage. By acting uniformly through the member 27, slight deformation of the press ring 26 can be prevented.

Embodiment 7 A tensioning mechanism according to the present invention shown in FIG. 9 uses a press ring 30 that is divided into two halves and has a scratch-preventing member 31 on the upper side. A hemispherical protrusion 32 is protruded at the position where it contacts the bolt, and the tip of the tensioning bolt 33 is recessed into a spherical seat.
Since the contact surface area of the tensioning bolt 33 is large and the surface precision is high, the pressing force during tightening acts uniformly through the scratch prevention member 31 to prevent slight deformation of the press ring 30. Can be done.

Embodiment 8 The tensioning mechanism according to the present invention shown in FIG. A hemispherical protrusion protrudes from the tip of the tensioning bolt 36, which serves as a self-aligning mechanism that enables uneven fitting between the two.Since the contact surface area of the tensioning bolt 36 is large and the surface accuracy is high, it is easy to tighten. The pressing force at the time of pressing is applied uniformly and the press ring 3
The slight deformation of No. 4 can be prevented.

Embodiment 9 A tensioning mechanism according to the present invention shown in FIG. 11 has a conical protrusion 38 with a missing head protruding from the upper surface of a press ring 37 at a position where it contacts the bolt, and a tip of a tensioning bolt 39. The part is formed in a conically recessed seat surface, and it is an automatic centering mechanism that allows concave and convex fitting between the two, and the contact surface of the tensioning bolt 39 has a large area and high surface accuracy. The pressing force when tightening is applied uniformly to press ring 3.
7 can be prevented from being slightly deformed.

[0028]

Effects of the Invention This invention improves the mechanical strength of the part of the press ring that the tensioning bolt contacts by increasing the cross-sectional shape of that part, and also prevents damage between the tensioning bolt and the press ring. By interposing a prevention member or using self-aligning means between the bolt and the scratch prevention member or between the bolt and the press ring, the press ring is prevented from shifting or being scratched when the bolt comes into contact with the bolt. This prevents slight deformation of the press ring, equalizes the tightening force applied to the press ring by the tensioning bolt, and enables high-precision tensioning of the inner peripheral edge, reducing the amount of slight deformation of the press ring. This reduces the flatness of the core material of the inner blade, which reduces the vibration of the inner blade due to slight deformation during cutting, and the runout of the inner blade due to resonance, reducing the cutting allowance. Stable cutting can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a top view and a longitudinal sectional front view of a press ring according to the present invention.

FIG. 2 is a top view and a longitudinal sectional front view of another press ring according to the present invention.

FIG. 3 is a top view and a longitudinal sectional front view of a conventional press ring.

FIG. 4 is a longitudinal sectional front view of the press ring according to the present invention.

FIG. 5 is a graph showing the deformation rate of the inner circumferential cutter due to a change in the shape of the press ring, and shows an explanatory diagram of the position of the tensioning bolt and its deformation rate.

FIG. 6 is a diagram illustrating the radial position of the inner peripheral cutter and a graph showing its stress distribution as the shape of the press ring is changed.

FIG. 7 is a perspective explanatory view of a split press ring according to the present invention.

FIG. 8 is a perspective explanatory view showing another example of the split type press ring according to the present invention.

FIG. 9 is a perspective explanatory view showing another example of the split type press ring according to the present invention.

FIG. 10 is a perspective explanatory view showing another example of the split type press ring according to the present invention.

FIG. 11 is a perspective explanatory view showing another example of the split type press ring according to the present invention.

FIG. 12 is a perspective explanatory view of the slicing device.

FIG. 13 is a perspective explanatory view showing a holder for the inner peripheral blade.

FIG. 14 is a vertical cross-sectional view showing details of the holder of the inner peripheral blade.

FIG. 15 is an explanatory diagram showing the positional relationship of tensioning bolts of a conventional inner peripheral blade.

[Explanation of symbols]

1 Inner peripheral blade 2 Diamond abrasive grain 3 Silicon ingot 4 Adhesive block 5 Indexer 6 Feeding table 7 Base 8 Electric motor 10 Rotating chuck 11 Bottom part 12 Groove 13 Top ring 14 Circumferential groove 15 Bolt 16 Press ring 17 Tensioning bolt 20 , 21, 22, 26, 30, 34, 37 Press ring 23, 27, 31 Scratch prevention member 24, 29, 3
2 Hemispherical protrusion 25, 28, 33, 36, 39 Tensioning bolt 3
5 Process 38 Headless conical process

Claims (4)

[Claims] [Claim 1] The outer peripheral part of the inner peripheral blade is placed on the upper circumferential end surface of the bottom part of the chuck, the top ring is screwed on to hold the inner peripheral blade, and the internal peripheral blade is built in by advancing and retracting the bolt that is screwed into the top ring. In the inner peripheral blade tensioning mechanism of the slicing device, which applies tension to the inner peripheral blade by bringing the press ring into contact with the outer peripheral part of the internal peripheral blade, the cross-sectional shape of the ring is made larger at the part where the tensioning bolt of the press ring comes into contact than at other parts. An inner peripheral blade tensioning mechanism of a slicing device characterized by the following. [Claim 2] The outer peripheral part of the inner peripheral blade is placed on the upper circumferential end surface of the bottom part of the chuck, the top ring is screwed on to hold the inner peripheral blade, and the internal peripheral blade is built in by advancing and retracting the bolt that is screwed into the top ring. In the inner peripheral blade tensioning mechanism of a slicing device that applies tension to the inner peripheral blade by bringing the press ring into contact with the outer peripheral part of the inner peripheral blade, a scratch-preventing member is interposed at least in the part of the press ring that the tensioning bolt contacts. An inner peripheral blade tensioning mechanism of a slicing device characterized by: 3. The inner peripheral blade tensioning mechanism for a slicing device according to claim 2, wherein automatic alignment means is used for the tip of the tensioning bolt and the upper surface shape of the scratch-preventing member. [Claim 4] The outer peripheral part of the inner peripheral blade is placed on the upper circumferential end surface of the bottom part of the chuck, the top ring is screwed on to hold the inner peripheral blade, and the internal peripheral blade is built in by advancing and retracting the bolt that is screwed into the top ring. In the inner peripheral blade tensioning mechanism of a slicing device that applies tension to the inner peripheral blade by bringing the press ring into contact with the outer peripheral part of the inner peripheral blade, we have used self-aligning means for the tensioning bolt tip and the top surface shape of the press ring. The slicing device features an inner blade tensioning mechanism.