JP2006272499A - Cutting method for ingot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting method for an ingot capable of lowering the cutting cost, achieving cutting with high flatness, and reducing waste in cutting. <P>SOLUTION: By this cutting method for an ingot using a wire saw, an adhesive and abrasive grain are sequentially supplied to a traveling wire of the wire saw, the adhesive is dried using drying air to fix the abrasive grain on the wire, and after that, the ingot is cut by the wire while a cutting liquid is supplied to the wire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for cutting an ingot, and in particular, a pseudo-fixed abrasive wire that fixes abrasive grains to a wire at the time of cutting, and an ingot suitable for cutting an ingot such as silicon single crystal, polycrystal, other compound semiconductors, and ceramics. It relates to a cutting method.

  Conventionally, ingot cutting of silicon single crystal or the like is performed while supplying cutting fluid (slurry) in which abrasive grains such as SiC are dispersed in water-soluble or water-insoluble liquid to the cutting part of the wire and ingot that travels. In this way, cutting with a free abrasive grain method is common (Patent Document 1). However, the cutting of the ingot by this free abrasive grain method has a problem that since the cutting fluid is not sufficiently supplied between the substrates to be cut, the temperature rises at the cutting part, and the flatness of the substrate decreases. In order to solve this problem, since a large amount of slurry is used, there is a problem that a lot of waste is generated during cutting.

  Then, in order to solve the problem with the loose abrasive method, a cutting method using a fixed abrasive wire in which the abrasive is fixed to the wire in advance has been proposed (Patent Document 2).

However, this fixed abrasive wire method has a problem that the manufacturing cost of the fixed abrasive wire is higher than that of the free abrasive method.
JP-A-8-323741 JP 11-10516 A

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a method for cutting an ingot that can be cut at low cost, can be cut with high flatness, and has little waste during cutting.

  In order to achieve the above-mentioned object, an ingot cutting method according to the present invention is an ingot cutting method in which an ingot is cut into a plurality of substrates using a wire saw. Supplying and drying the adhesive using dry air to fix the abrasive grains onto the wire, and then cutting the ingot with the wire while supplying cutting fluid to the wire. To do.

  According to the ingot cutting method of the present invention, it is possible to provide an ingot cutting method that is low in cutting cost, capable of cutting with high flatness, and has little waste during cutting.

  Hereinafter, an embodiment of an ingot cutting method according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a conceptual diagram of a wire saw used in the ingot cutting method according to the present invention.

  As shown in FIG. 1, the wire saw 1 is composed of three grooved rollers 2 (2 a, 2 b, 2 b) that are rotatably provided and a wire 3 a that is stretched between the grooved rollers 2. A roller mechanism portion 4 having a row 3A, a workpiece holding mechanism portion 5 that holds an ingot W such as a silicon single crystal ingot that is pressed and cut by the wire 3a, and a workpiece feeding mechanism portion to which a workpiece plate 6 is attached ( (Not shown), the workpiece holding mechanism 5 is movably attached to the workpiece feeding mechanism, and the roller mechanism 4 and the workpiece feeding mechanism are attached to an apparatus base (not shown). .

  Of the three grooved rollers 2 (2a, 2b, 2b), the grooved roller 2a is a drive roller driven by a roller drive motor (not shown), and the other grooved rollers 2b, 2b are driven rollers. The wire 3a of the wire row 3A is reciprocated by driving the grooved roller 2a which is a drive roller.

  A pair of abrasive grain forming units 7 and 7 are provided on both sides of the ingot W. The abrasive grain forming units 7, 7 are provided with an adhesive jet nozzle 7a, an abrasive jet nozzle 7b, and a dry air jet nozzle 7c in this order from the driven rollers 2b, 2b.

  As shown in FIG. 2, the abrasive grain forming units 7, 7 spray an adhesive from an adhesive spray nozzle 7 a onto a wire 3 a that is traveled and the abrasive grains are not fixed, and the adhesive is further adhered. Abrasive grains are sprayed onto the wire 3a from the abrasive grain spray nozzle 7b to attach the abrasive grains to the wire 3a, high-temperature dry air is sprayed from the dry air spray nozzle 7c, and in-situ immediately before cutting. This is for forming the pseudo fixed abrasive wire 3.

  Further, a pair of cutting fluid supply nozzles 8 and 8 are provided between the ingot W and the abrasive grain forming units 7 and 7 so as to supply the cutting fluid to the wire 3 to which the abrasive grains before cutting are fixed. It has become.

  As shown in FIGS. 1 and 2, the ingot cutting method according to the present invention is performed as follows.

  During the cutting process of an ingot, for example, a silicon single crystal W, the traveling wire 3a and the non-traveling side abrasive grain forming unit 7 are actuated, and an adhesive is sprayed from the adhesive spray nozzle 7a onto the material wire 3a. Abrasive grains are sprayed on and attached from the abrasive grain spray nozzle 7b, and high-temperature dry air is sprayed from the dry air spray nozzle 7c to form the pseudo fixed abrasive wire 3.

  Further, the cutting fluid is supplied to the pseudo fixed abrasive wire 3 from the cutting fluid supply nozzle 8 on the opposite side, the pseudo fixed abrasive wire 3 and the ingot W are moved relative to each other, and the ingot W is moved to a plurality of wafers by grinding action. Disconnect.

  In this cutting process, since the pseudo fixed abrasive wire 3 is in a state where the abrasive grains are fixed to the wire 3a, a sufficient amount of cutting fluid is supplied between the substrates to be cut, and the temperature rises at the cut portion. Therefore, the flatness of the substrate can be increased, the amount of cutting fluid supplied can be reduced, and the generation of waste can be reduced. Furthermore, unlike the fixed abrasive wire that fixes the fixed abrasive wire to the wire in advance, the pseudo fixed abrasive wire 3 is inexpensive because the abrasive particles are fixed to the wire on the spot, and is regenerated and used immediately before cutting. Is possible.

  According to the ingot cutting method of the above embodiment, by using a pseudo fixed abrasive wire and a cutting fluid in combination, the cutting cost is low by using an inexpensive wire, and cutting with high flatness is possible. A method for cutting an ingot with little waste is realized.

  Using the ingot cutting method according to the present invention, wire tension of 25 mm, pseudo-fixing abrasive grains # 1500, wire speed of 750 m / min, cutting fluid of # 1500, machining time of 10 hours, diameter of 200 mm, long A silicon ingot having a thickness of about 500 mm was cut, and the flatness of the cut silicon wafer was measured (Example). Next, as a comparative example, the pseudo fixed abrasive wire was not used, and only # 1500 was used as the grinding fluid. The other conditions were the same as in the example, and the silicon ingot was cut to measure the flatness of the silicon wafer ( Conventional example). Moreover, the usage-amount of the cutting fluid used for the process of said 1 silicon ingot was compared with the Example and the prior art example.

The results are shown in Table 1.

  As can be seen from Table 1, it was confirmed that when the pseudo-fixed mounting wire and the grinding fluid were used in combination, the flatness was improved as compared with the case using only the grinding fluid.

  In addition, by using the pseudo fixed liquid abrasive wire and the grinding liquid in combination, it was possible to reduce the disposal of about 100 kg of the grinding liquid in the processing of one silicon ingot.

The conceptual diagram of the wire saw used for the cutting method of the ingot which concerns on this invention. The conceptual diagram of the abrasive grain adhering method in the cutting method of the ingot which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire saw 2 (2a, 2b, 2b) Grooved roller 3 Pseudo fixed abrasive wire 3a Wire 3A Wire row 4 Roller mechanism part 5 Work holding mechanism part 6 Work plate 7 Abrasive grain formation unit 7a Adhesive injection nozzle 7b Abrasive grain injection Nozzle 7c Dry air injection nozzle 8 Cutting fluid supply nozzle

Claims (1)

In an ingot cutting method in which an ingot is cut into a plurality of substrates using a wire saw, an adhesive and abrasive grains are sequentially supplied to the wire traveling on the wire saw, the adhesive is dried using dry air, and the abrasive is A method for cutting an ingot, characterized in that the grains are fixed on the wire, and then the ingot is cut with the wire while supplying a cutting fluid to the wire.

Images