JPS58173609A - Cutter for thin piece - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Part 11f1 of the Invention] The present invention relates to a thin slice cutting device, and more particularly to a thin slice cutting device that controls the feeding speed of an object to be cut.

[Technical background of the invention and its problems] Conventional wafers for semiconductors are required to have high wafer precision due to the trend toward ultra-large scale integration (LSI) and the like. Wafers are made by slicing ingots, and during this slicing, the wafers may be damaged or warped, which determines the accuracy of the wafers.

Generally, ingots are sliced by rotating a blade with a diamond inner edge at high speed and feeding the ingot into the blade at a constant speed. During this cutting, there is an eccentricity of the blade, and the contribution of the blade to off-cutting is only about 10% of the inner circumference, so the cutting resistance during cutting changes, and the grade of base metal changes according to this change. The ninth blade suffers from fatigue due to repeated damage. Fatigue of the base metal of the blade is not uniform depending on the blade, but there are fatigue strengths and weaknesses due to non-uniformity of the material of the base metal.In areas that are weak to fatigue, the diamond on the cutting edge peels off at a contribution rate of 109g, making the blade unable to cut. This may cause damage to the wafer. In this case, even the part that is resistant to fatigue has a limit of fatigue, and at some point it becomes impossible to cut the wafer, resulting in damage to the wafer.The blade cost for each rounded wafer is generally high. . Further, when the cutting ability of the blade decreases, the blade becomes deflected, causing warping of the wafer.

As described above, at present, the wafer 1 is fed at a constant speed even when the cutting ability of the blade decreases, and as the cutting ability of the blade decreases, the life of the blade and the precision of the wafer deteriorate.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional difficulties, and includes providing a detection section for detecting the cutting resistance of the blade at a location where the ingot is held, and comparing the detection section 11 with a predetermined set value. Providing a control unit to control the speed at which Ueno is fed into the blade will extend the life of the blade.

Another object of the present invention is to provide a thin section cutting device that reduces wafer breakage and warpage.

[Summary of the invention I! ] The present invention includes a rotating blade having a diamond inner circumferential cutting edge, a drive unit that feeds an object to be cut to the blade, a holding unit that holds the object to be cut, and a cutting resistance provided in the holding unit. The cutting resistance of the blade is controlled by the cutting resistance of the ingot holding part, and the control part controls the feeding speed of the object to be cut by comparing the detection value from the detection part with a predetermined setting value. This is common in thin-section cutting machines that reduce variations in the cutting resistance of the blade by measuring the cutting force at different points and changing the feeding speed between inbots.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG.
(in the direction of the arrow), a holding section 5 that holds the ingot 3, a detection section 6 provided in the holding section 5 that detects cutting resistance, and a detection value from the detection section 6 and a predetermined set value. and a control section 7 that controls the feeding speed of the ingot 3 by comparing the values.

The detecting section 6 measures the strain of the ingot 3 by installing a strain gauge 8 in the mounting part of the ingot 3, amplifies this with an amplifier (not shown), and sends it to the control section T as a so-called detected value (cutting resistance). ing. In the control section T,
The detection value from the detection unit 6 and a predetermined set value are compared and calculated, and a command is issued to the drive unit 4 to slow down the feeding speed of the ingot 3 when the cutting resistance is high, and to speed it up when the cutting resistance is low. By varying the wafer feed speed according to the cutting resistance, wafer damage and warping are prevented and blade life is extended.

As shown in the graph of Fig. 2, the warpage of the wafer is approximately 30 μm in the conventional system, whereas the average warpage in the apparatus of the present invention is approximately 2 μm.
It decreases to 5 μm. In addition, the life of the blade, that is, the number of wafers cut per blade, is improved from 500 to 3,000 in the conventional method to 2,000 to 4,000 in the device of the present invention, as shown in the graph of FIG. The effect was that the number of sheets cut was narrow and the number of sheets cut was large.

"Effects of the Invention" As is clear from the above embodiments, according to the present invention, a detection section for detecting the cutting resistance of the blade is provided at a location where the ingot is held, and the detected value and a predetermined film constant value are set. In comparison, by providing a control unit that controls the speed at which the wafer is fed into the blade, it is possible to prevent excessive loads from being applied to the ingot and the blade, thereby reducing wafer breakage and warping, and prolonging the life of the blade. It is possible to increase the number of sheets to be cut, thereby improving quality, increasing productivity, and reducing costs.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the thin slice cutting device of the present invention, FIG. 2 is a graph showing the distribution of wafer deformation by the thin slice cutting device of the present invention, and FIG. 3 is a blade using the thin slice cutting device of the present invention. 3 is a graph showing the distribution of the number of wafers cut. 1...Diamond inner peripheral blade, 2...Blade 3
... Ingot 4 ... Drive section 5 ... Holding section 6 ... Detection section T ... Control section
8...Strain cage B)...Conventional flake cutting device (B)...Flame cutting device of the present invention

Claims (1)

[Claims] A rotating blade having a diamond inner circumferential edge, a driving section that feeds the object to be cut to the blade, a holding section that holds the object to be cut, and a detection section provided on the holding section that detects cutting resistance. and a control section that compares the detection value from the detection section with a predetermined set value to control the feeding speed of the object to be cut.