JPH0661752B2 - Inner peripheral blade type holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an inner circumference of an inner circumference blade type slicing machine used when slicing a thin plate having a thickness of several hundreds of microns from a brittle material such as a silicon ingot. The present invention relates to a blade type blade holding device.

[Conventional technology]

A thin plate such as a semiconductor wafer used for manufacturing a semiconductor device is sliced from an ingot by using a very thin blade (cutting blade) in order to improve production efficiency. Therefore, in order to give the required rigidity to the thin blade and slice the thin plate accurately, the blade is generally used an inner peripheral blade method in which a diamond abrasive is bonded to the inner peripheral edge of the opening in a donut shape. The outer peripheral side is stretched and held by a blade holding device with a predetermined tension.

FIG. 4 is a schematic cross-sectional side view of an inner peripheral blade type blade holding device H which has been conventionally used.
It is designed to be sandwiched between a tension ring 3 part above a strawberry-shaped bottom ring 2 connected to the spindle 1 and a top ring 4 which is paired with the ring part and attached by a bolt or the like.

It is well known that the tension of the blade B is adjusted by blade pressing bolts (not shown) provided on the circumference of the top ring 4. This tension adjustment is such that the pressing force of the pressing bolt on the circumference varies depending on the location because of the presence of a difference in the tensile strength in the rolling direction in the blade B, so-called anisotropy.

That is, the anisotropy is generally in two directions (x, y) that are substantially orthogonal to each other.
Since it is known that the x-direction side is y
If the tensile strength is larger than that in the direction, the pressing force in the x direction is y
The setting is stronger than that on the direction side.

[Problems to be solved by the invention]

However, when the pressing force is varied depending on the blade portion as described above, it gives a non-uniform stress load to the entire holding device H, which eventually causes the blade to shake during cutting operation, damage to the cut thin plate, and cut thickness. It was likely to become a serious cause of troublesome situations such as variations in.

FIGS. 5 and 6 are for explaining the deformation mode of the holding device due to the above stress. In the figure, the solid line shows the blade holding device in the normal state, and the chain double-dashed line shows the deformed state.

That is, in the figure, when the x direction side of the blade B is set with a stronger pressing force than the y direction side as described above, a similar load is generated in the blade holding device H as a reaction force thereof. In this case, the tension head 5 composed of the top ring 4 and the tension ring 3 of the holding device has the fifth planar shape.
As shown by the two-dot chain line in the figure, the x-direction side is displaced inward,
The y-direction side is displaced outward so that it becomes an elliptical shape as a whole. However, such deformation of the tension head 5 is
This also affects the strawberry-shaped bottom ring 2. That is,
Since the tension head 5 part is a ring type, its deformation is elliptical, but the bottom ring 2 part which is integrated from the head part to the side wall part becomes an elliptical deformation similar to the above due to the existence of the bottom plate 6. However, as shown in FIG. 6, the periphery of the bottom plate is displaced upward in the x direction (shorter diameter direction),
On the y-direction side (longitudinal direction), the periphery of the bottom plate is displaced downward.
This displacement directly affects the tension head 5. As described above, the tension head 5, which is an ellipse in plan view, is deformed in an arc with the periphery of the bottom plate 6 as a fulcrum because the deformation of the bottom plate 6 spreads laterally, and the blade surface on the x direction side as shown in the figure. It will be displaced to the upper side of the normal level and to the lower side on the y direction side, and eventually the entire surface will have a wavy uneven shape, which will appear as the blade runout of the blade together with the surface runout of the bottom plate 6 at the time of cutting. It becomes. The present invention aims to solve the above conventional problems.

[Means for solving problems]

A rotary plate fixed to the spindle shaft, a tension head, and provided between the rotary plate and the tension head at 90 ° intervals to connect the rotary plate and the tension head,
A leaf spring disposed so as to be flexibly displaceable in the radial direction, and an inner peripheral blade that is stretched and held by the tension head and is positioned in relation to the leaf spring in consideration of anisotropy. It is characterized by

[Action]

The anisotropic (x, y) direction of the inner peripheral blade is matched with the position of the leaf spring on the rotary plate, and in this state, the blade is stretched from the top ring with a desired pressing force. The tension causes the blade to have different tensions on the x-line and the y-line of the anisotropic portion. For example, if the x-line has a large tension, the tension head in that direction has a short diameter and the y-line direction deforms to a long diameter. As a result of this deformation, the leaf spring absorbs the amount of deformation and is displaced, and the stress due to the deformation is not transmitted to the rotating plate that is the bottom plate. Therefore, it is possible to prevent the occurrence of blade runout of the inner peripheral blade due to stress deformation of the rotary plate. That is, since the tension head only displaces in the radial direction, which is the direction in which the tension head converges to the original posture form of the blade in the free state, it does not form a defective wavy uneven surface unlike in the conventional case.

〔Example〕

 Preferred embodiments of the present invention will be described below with reference to the drawings.

1 and 2 relate to an embodiment of the present invention. In the drawings, 10 is a rotary plate connected to a drive source such as a motor by a spindle (not shown) by a known means, and a conventional bottom ring bottom plate. Equivalent to. Reference numeral 11 denotes a tension ring, which has a flat upper surface to form required recessed grooves, bolt screw holes and the like similar to the conventional one, and a lower surface is provided with a connection structure with a tension head support member described later. Reference numeral 12 denotes a top ring, which forms a tension head 13 by pairing with the tension ring 11, and an inner peripheral blade type blade 14 is sandwiched between the both rings to fix the blade from the top ring top surface with a large number of bolts or the like. I am trying to stretch it. This blade clamping and tensioning is performed by a known means. 15
Is a tension head support member standing upright at four locations around the upper surface of the rotary plate 10 at equal intervals.
Leaf springs 16, 16 that are attached in parallel to the support block 10a attached at 0 at appropriate intervals, and the head base 1 that is attached on the pair of leaf springs 16
7 and a connecting member 18 such as a bolt that connects the head base and the tension ring 11. As shown in FIG. 1, the leaf springs 16 are arranged so that their spring surfaces are parallel to the tangential direction of the rotation locus of the rotary plate 10, in other words, perpendicular to the radial direction of the rotary plate. As a result, the rotary plate 10 can be displaced only in the radial direction when the rotary plate 10 rotates in the free state in which the tension head is not supported. 1
Reference numeral 9 denotes a safety support leg arranged at a substantially intermediate position between the tension head support members 15. The tension head 13 is deformed to a large extent or the tension head support member 15 is damaged due to a shortage during operation of the machine. It is provided in order to prevent these in the case of desorption, and is not necessarily required, but the safety of the device is further improved by providing it. However, the safety support leg should not interfere with the tensioning of the blade 14 in the normal state, and therefore, as shown in FIG. 3, for example, the support leg holder 19 fixed to the rotary plate 10 side.
A is a hollow casing, and the support leg pin 19b fixed to the tension head 13 side is positioned in the casing with a slight gap.

With the above configuration, the inner peripheral blade 14 is stretched,
When setting, there are two possible methods and procedures. One is a mode in which the tension head 13 is removed from the support member 15 and a blade is stretched at another place, and then the tension head 13 is attached and fixed to the support member 15. The other is a mode in which the tension ring 11 of the tension head 13 is supported by the support member 15. This is a mode in which the blade is stretched while being attached to the.

However, since the apparatus of the present invention aligns the anisotropic direction of the blade 14 with the position of the tension head support member 15, any of the above procedures will not be a problem.

Therefore, if it explains temporarily by the latter procedure, the inner peripheral blade 14 is mounted on the upper surface of the tension ring 11 fixedly attached to the tension head support members 15 at four locations via the connecting members 18. At this time, assuming that the anisotropic directions of the blades are, for example, x and y, the x-direction line and the y-direction line are respectively placed on the tension head support member 15 so as to match each other. Next, the top ring 12 is placed on the tension ring 11, and the blade 14 is sandwiched and fastened to the tension ring 11 by a known means, and the blade 14 is fixed by a blade pressing bolt (not shown).
Then, the tension applying portion in the holding portion is pressed to apply the required tension to the blade. However, since the pressing of the lever is different in the x and y directions of the blade as described above, for example, if the tensile strength in the x direction is larger than that in the y direction, the bolt pressing force on the x direction side is larger than that on the y direction. Also big. Then, the tension on the x-direction side becomes larger than that on the y-direction, so the reaction force naturally becomes large on the x-direction side,
That is, a stress that makes the diameter of the tension head 13 in the x direction shorter than the diameter in the y direction acts on the relevant portion of the tension head. When this stress load is larger than the rigidity of the tension head 13, the head is displaced to the short diameter on the x direction side and to the long diameter on the y direction side. However, this displacement propagates to the leaf springs 16 and 16 of the tension head support member 15, but since the support member is displaceable in the radial direction of the rotating plate 10 which is erected upright as described above, it can be displaced in accordance with the radial displacement. It will be displaced. Since the leaf spring 16 of the present invention positively imparts the displacement response in this way, the tension head 13
The radial displacement is absorbed by the leaf spring 16, and the displacement stress is hardly transmitted to the rotating plate 10 which is erected and supported. Therefore, the displacement stress due to the tension of the blade 14 is hardly applied to the rotary plate 10 regardless of the tension of the blade 14.

Further, the radial displacement of the tension head 13 physically affects the height of the blade 14 in the same manner as the above-mentioned conventional one,
In the case of the present invention, since there is no displacement of the rotary plate 10, there is no accumulated displacement, and therefore the height displacement has a value according to the displacement angle of the support member 15. In practice, it can be suppressed to a few microns at most. In other words, such a height displacement does not cause the quality of the work material to deteriorate due to the blade runout when the blade rotates, and it can be said that the blade runout does not substantially occur.

Further, according to the above-mentioned configuration, since the leaf spring 16 and the safety support leg 19 are erected on the rotary plate 10 as required, the chips, cutting water, etc., generated when the work material is blade-cut. The waste will be quickly discharged to the outside through the gap of the support member 15 or the like.

〔effect〕

As described above, according to the present invention, when the radial displacement of the tension head due to the anisotropy of the inner peripheral blade type blade occurs, the tension head absorbs the radial displacement, and the rotating plate that is the base plate absorbs it. Since the displacement stress is not transmitted, the rotating plate is not displaced due to the tension of the blade, and the displacement due to the height position of the inner peripheral blade due to the displacement of the bottom plate (rotating plate) as in the conventional case, that is, the blade surface It is possible to prevent blade runout due to it without causing waviness.

In addition, since the leaf spring and the safety support leg are installed upright between the tension head and the rotating plate and the other parts are open, sludge such as chips generated by cutting the work material or cutting is generated. The ability to discharge debris and the like is greatly improved, and the occurrence of rotational vibrations and the like due to these can be prevented.

Further, conventionally, in order to prevent rotational vibration and the like of the bottom ring as much as possible, a tray was provided inside the bottom ring as a receiving member for sludge and the like. Since it is good, the above-mentioned saucer structure and the like are not required, and as a result, it is possible to provide a holding device for an inner peripheral blade, which has a simple structure as a whole and is excellent in practicability such as performance, economy and workability.

[Brief description of drawings]

FIG. 1 is a plan view of an inner peripheral blade type blade holding device according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are a front view and a side view showing a specific essential configuration of the present invention. FIG. 4 is a configuration view of a safety support leg blade, FIG. 4 is a side view illustrating the configuration of a conventional inner peripheral blade type blade holding device, and FIG. 5 is a plan view of FIG. 4 illustrating displacement of a tension head due to blade tensioning. 6 (a) and 6 (b) are side surface explanatory views of the main part of the blade holding device in the displaced state of FIG. 10 ... Rotating plate, 11 ... Tension ring, 12 ...
Top ring, 13 ... Tension head, 14 ... Inner peripheral blade type blade, 15 ... Tension head support member,
16 ... Leaf spring, 19 ... Safety support leg.

Claims (1)

[Claims] 1. A rotary plate fixed to a spindle shaft, a tension head, and the rotary plate and the tension head are provided at 90 ° intervals so as to connect the rotary plate and the tension head to each other in a radial direction. An inner peripheral blade comprising a leaf spring arranged so as to be flexibly displaceable, and an inner peripheral blade which is stretched and held by the tension head and positioned and arranged in relation to the leaf spring in consideration of anisotropy. Mold blade holding device.