JPS58165965A - Inner circumferential type diamond cutting grinding wheel - Google Patents

Abstract

PURPOSE:To negate anisotropy of the material and hold circular trueness of the grinding wheel after it is braced up on a frame in such a way that inner circumference of a base metal which is made of a rolled material possessing anisotropy is manufactured to be a true circle, and width of the grinding wheel layer which is electrodeposited onto the inner circumference is formed narrowly in the rolling direction and widely in the transverse direction of the base metal. CONSTITUTION:A cutting grinding wheel forms its grinding stone part in such a way that diamond abrasive grain 5 is stuck by means of a metal 6, such as nickel or another. In the event that cutting is done by bracing up the base metal 1 as if it were a drumhead, the reason why the inner circumferential circle 7 is made into an ellipse which is long in the rolling direction 8 and short in the transverse direction is that elongation attributable to tension in the circumferential direction of the inner circumferential circle 7 is large in the portions 11, 11' and small in the portions 12, 12'. In consequence, width W of the grinding wheel layer is made large as w1, w1' in the portions 11, 11', and narrow as W2, W2' in the portions 12, 12'. Width W between the portions 11 and 12 is made into an ellipse 13 by gradually changing the span between W1 and W2.

Description

[Detailed description of the invention] Inner circumference 2VC of a thin metal circle jJi/ (hereinafter referred to as base metal)
It has a structure with a diamond grinding wheel section 3 along its length, and is also called a blade. It is fixed with bolts on the outer periphery, stretched up like the skin of a drum, and rotated at high speed for use.

When stretched, the metal plate of the Kyop base metal maintains a good flatness despite its thinness, and has high resistance to lateral vibration of the inner peripheral portion, that is, the grindstone portion. For this reason, it has features that cannot be obtained with ordinary peripheral cutting wheels, such as being able to cut large-sized workpieces with high precision and with a small cutting width that is removed as chips, and is suitable for cutting semiconductor materials. It has been awarded.

The disadvantage is that when a uniform tension is applied over the entire circumference of the outer circumference and tensioned, the inner circumference, that is, the grindstone portion, deforms and becomes elliptical. The metal thin plate of the base metal is work hardened by rolling! This is because the material exhibits anisotropy because it is used with increased strength, and the elastic modulus is different in the rolling direction and the transverse direction.

Although the ellipticity is small, loss of roundness in the grinding wheel causes radial runout, which is the most disliked thing in diamond grinding wheels, so it is always a problem when cutting high-quality semiconductor wafers.

As a solution, a method has been proposed in which the inner periphery is made into an elliptical shape in advance (4I Kosho J6-DA5RS).

The difference in the amount of radius expansion due to tension cancels out the initial radius difference, resulting in a perfect circle.

However, from the viewpoint of the manufacturing process of the base metal and in order to maintain accuracy, it is desirable that the inner periphery of K is a perfect circle corresponding to the outer periphery.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inner periphery diamond cutting whetstone in which the inner periphery of the base metal of an anisotropic rolled material is made into a perfect circle and which maintains the perfect circle even after tensioning.

This type of cutting whetstone ilt'#L bonding method is used to fix the cutting whetstone to a diamond abrasive grain base metal to form a whetstone portion. FIG. 2 is an enlarged sectional view of the vicinity of the grinding wheel, where l is an alloy and c is the inner periphery of the diamond abrasive grains 5, which are fixed on the 0 alloy using a metal base such as nickel by electroplating.

The part that mainly performs the grinding action during cutting is the tip 7, but the reason why the electrodeposited grindstone layer is also formed on the plate surface of the base metal over the width WK is to firmly press the adhesion of the grindstone part to the base metal. It also has the effect of preventing the cutting mK base metal of the workpiece from coming into contact and rubbing, and the effect of polishing the cut surface.

The thickness T over the width W is approximately three times as large as that of the base metal, and the grinding wheel portion has a strength P greater than that of the alloy itself. In particular, the resistance to tension in the circumferential direction of the inner core, that is, the apparent elastic modulus is high.The present invention focuses on this point, and corrects the anisotropy of the elastic modulus along the inner circumference by the width W of the grinding wheel layer. It is.

Due to tension K, the inner circumference in Fig. 3 becomes an elliptical shape io that is longer in the rolling direction l and 9Vc shorter in the transverse direction, because the elongation of the inner circumference due to the tension in the circumferential direction is //, //' It is large in the part of , and compared to this, it is small in /J'O4@S
@Because it is hard, the width W of the grinding wheel layer is // , //'
As wide as y,,wi in the part, lko, l!
In the part of the horse, make it narrower like a curse.

The width of the grinding wheel layer is the width v FiW between the part // and the part l.
.

Changes between the horse and the horse. In other words, the grindstone layer is
The inner periphery is circular, and the outer periphery is an ellipse/J with the short axis in the rolling direction.

Example Made from a rolled plate of stainless steel 8U830 with thickness d/ ■Outer diameter: ■Inner diameter/! On the base metal of t3wm, refer to the maximum width W1 (■) and the minimum width - (■). The abrasive layer is set in the shape of /J, the bond is electrodeposited nickel, and the abrasive grains are diamond with a grain size of ~A□)m.

Attach this to a hydraulic tension frame and tension it to create an inner circumference of 1
Measure the amount of increase in radius and then increase the width of the whetstone layer around the entire circumference 7
For comparison, the increase in radius was measured under the same conditions for a higher grade of the same specification, that is, a conventional standard product, except that the tll knee was kept constant. The following table shows typical measurement examples.

The increase in radius is generally smaller in the blades of the present invention, and is only about the same as in the conventional product because the 0-layer width W of the grinding wheel is large on average, and the apparent modulus of elasticity with respect to elongation in the circumferential direction is large. It is. In other words, it has been confirmed through measurements that the grindstone portion has high rigidity, and the XD blade of the present invention also has strong resistance to lateral vibration. This is also advantageous in terms of cutting performance.

The increase in radius is measured by dividing the entire circumference into 74 equal intervals, and then averaging the measured values at the points separating 1 to 0 to eliminate eccentricity. The amount of increase in elastic anisotropy is large in the rolling direction and small in the transverse direction, with an average value rh.

The difference between the maximum and minimum values is shown in the bottom column of the table above.

This difference indicates a tendency toward ovalization, and in conventional products, the value increases as the oil pressure is increased. In other words, ovalization becomes noticeable. On the other hand, with the ID blade of the present invention, the effect is clearly seen when the oil pressure exceeds vca, and the non-uniformity of the radius increase is very small, and the ovalization is almost negligible.
It has become a degree.

The internal diamond cutting grindstone of the present invention maintains a perfect circle even after tensioning and can eliminate the above-mentioned conventional drawbacks.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional internal diamond cutting wheel.
FIG. 2 is a partially enlarged cross-sectional view, and FIG. 3 is a front view of an internal diamond cutting grindstone according to the present invention. 7-Inner circumference, t-Rolling direction, 9-Transverse direction, io・
... Oval procedural amendment (voluntary) ■, Indication of the case % Application No. 57-43044 2, Title of the invention Inner circumferential diamond cutting grindstone 3, Relationship with the person making the amendment Patent Dejima type Asahi Diamond Industrial Co., Ltd. Company 4, Agent 5, Date: Showa, Month, Day 6
, subject to correction

Claims (1)

[Claims] The width of the grinding wheel layer attached to the inner circumference Kt of the base metal of the rolled metal material is narrowed in the rolling direction and widened in the lateral direction, and the width of the grinding wheel layer is gradually changed in the middle so as to connect the two. Circumferential diamond cutting wheel.