JP3967969B2 - Wire saw - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire saw, and more particularly to a wire saw for slicing a silicon ingot or the like.
[0002]
[Prior art]
There is a wire saw as an apparatus for cutting a wafer having a certain thickness from a semiconductor silicon ingot. In this wire saw, a single wire such as a piano wire having a diameter of about 100 to 300 μm is wound around a number of grooves usually provided on 2 to 4 spacing rollers and arranged parallel to each other at a constant pitch. Run the wire in a certain direction or in both directions. The silicon ingot is pressed against the wire and sliced while supplying a cutting fluid in which abrasive grains such as SiC are mixed in oil or water called slurry. With this wire saw, many silicon wafers can be sliced at the same time, and since the slicing accuracy is high compared to other slicing methods that use outer peripheral blades and inner peripheral blades, etc., the wires used are thin. Has the advantage of reducing kerf loss.
[0003]
[Problems to be solved by the invention]
However, in the conventional wire saw as described above, since the surface of the wire is very smooth, the ability to hold the slurry even if it is supplied to the surface is weak, and the wire is traveling at high speed. Falls right below. For this reason, there is a problem that the slurry is difficult to be supplied to a portion where the wire and the silicon ingot to be cut are in contact, and the slicing speed cannot be increased.
[0004]
In order to cope with such a problem, the wire is twisted, a groove or a hole is formed on the surface of the wire (for example, Japanese Patent Application Laid-Open No. 11-10514), and the cross-sectional shape of the wire is a polygon or an ellipse. It has been proposed that a plurality of strands used for the wire are twisted and that the material thereof is carbon fiber (for example, JP-A-9-254006).
[0005]
However, all of these methods have the problem that the processing of the wire takes a lot of man-hours and expensive materials are used, so that the wire becomes expensive.
[0006]
This invention is made | formed in view of the problem of such a prior art, and it aims at providing the wire saw which can supply the wire with the high capability to hold | maintain a slurry.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the wire saw according to the present invention, the wire supplied from the supply reel is arranged between a plurality of interval holding rollers and wound around the take-up reel, and the plurality of intervals are held. In a wire saw that slices a silicon ingot while supplying slurry between rollers for use, a container filled with one or more hard particles of silicon carbide, diamond, and alumina is disposed on the supply reel side, in the roughened surface of the wire by passing through the inside of the vessel a wire said hard particles are filled and supplying to said interval holding roller.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing a configuration of a wire saw according to the present invention. In FIG. 1, 1 is a nozzle, 2 is a slurry receiver, 3 is a silicon ingot, 4 is a slicing base, 5 is a spacing roller, 6 is a wire, 7 is a dip tank, 8 is a wire supply reel, and 9 is a hard particle. The container 11 is a hard particle.
[0010]
In the wire saw of the present invention, a plurality of spacing rollers 5 are arranged apart from each other, and the wires 6 are folded back and stretched so that the spacing between the plurality of spacing rollers 5 is maintained at a predetermined interval. The silicon ingot 3 to be sliced is arranged.
[0011]
A wire 6 is supplied from a wire supply reel 8 to the interval holding roller 5, and a container 9 containing hard particles is provided between the wire supply reel 8 and the interval holding roller 5.
[0012]
In addition, a slurry receiver 2 with a nozzle 1 is provided on the silicon ingot 3. The slurry receiver 2 is provided to eliminate the unevenness of the portion to which the slurry is supplied. That is, it is provided to supply the slurry uniformly over the entire length of the slice width of the silicon ingot 3.
[0013]
The silicon ingot 3 is a rectangular parallelepiped of about 150 × 150 × 300 mm manufactured by, for example, a casting method, and, for example, two of them are sliced simultaneously.
[0014]
The slicing base 4 is for holding the silicon ingot 3, and the silicon ingot 3 is bonded thereto using an adhesive.
[0015]
The slicing base 4 to which the silicon ingot 3 is bonded is set on a holder (not shown) between the slurry receiver 2 and the wire 6 so that the silicon ingot 3 faces downward. The holder can be controlled to move up and down, and the silicon ingot 3 can be pressed against the wire 6 under the holder by pushing down the holder.
[0016]
The distance maintaining roller 5 disposed at the lower outer portion of the silicon ingot 3 has a diameter of 150 to 250 mm and a length of 400 to 500 mm, and is generally made of urethane rubber or the like, and has a wire with a pitch of about 400 to 600 μm on the surface thereof. A large number of grooves (not shown) 6 are formed. Two spacing rollers 5 are arranged at the same height at an interval of about 500 mm.
[0017]
The wire 6 has a diameter of 140 to 180 μm and is supplied from the wire supply reel 8, and is arranged in a spiral manner between the two spacing rollers 5 at the above pitch. Note that the wire 6 is generally a piano wire such as JIS G 3502 SWRS82A, which has been plated with brass and copper as main components.
[0018]
The dip tank 7 is disposed at the lowermost part for collecting slurry and collecting chips generated when slicing.
[0019]
FIG. 2 is an enlarged cross-sectional view of the container 9 portion of FIG. The container 9 is filled with hard particles such as SiC, diamond, and alumina. The container 9 is disposed between the wire supply reel 8 and the interval maintaining roller 5, and holes are formed at both ends thereof so that the wire 6 travels while passing through the container 9.
[0020]
In the above state, the wire 6 is rotated by rotating the roller 5 for maintaining the distance at high speed while supplying an appropriate amount of slurry to the wire 6 through the slurry receiver 2 below the slurry nozzles 1 provided in the upper part of the apparatus. Is driven at 400 to 700 m / min, and the slice base 4 holding the silicon ingot 3 is lowered to press the silicon ingot 3 against the wire 6 to slice the silicon ingot 3.
[0021]
In this invention, the surface (only a brass plating layer or both a brass plating layer and a wire main body) is made rough by making the wire 6 pass in the container 9 containing hard particles, such as SiC. As a result, the ability to hold the slurry is higher than that before the roughened surface, the slurry is easily supplied to the portion where the wire 6 and the silicon ingot 3 are in contact, the slicing speed can be increased, and the slicing time can be increased. It can be shortened. The container 9 containing the hard particles that allow the wire 6 to pass is placed behind the wire supply reel 8 of the multi-wire saw, and the wire 6 is allowed to pass through the container 9 so that the slurry can be held with little cost. Wire 6 can be used.
[0022]
FIG. 3 is an enlarged photograph showing the surface state of the wire 6 before allowing the container 9 to pass through. There is almost no unevenness on the surface, and the surface is smooth. When the wire 6 is immersed in the slurry liquid and pulled up, the slurry droplets adhering to the wire 6 immediately flow down along the wire 6.
[0023]
FIG. 4 is an enlarged photograph showing the surface state of the wire 6 passed through the container 9 containing hard particles. The surface of the wire 6 has countless fine scratches in the traveling direction of the wire 6 and is rough. When the wire 6 was dipped in the slurry liquid and pulled up, the slurry droplets adhering to the wire 6 did not flow down at all.
[0024]
【The invention's effect】
As described above, according to the wire saw of the present invention, a container filled with one or more hard particles of silicon carbide, diamond, and alumina is disposed on the supply reel side , and the wire is hardened By passing through the container filled with particles , the surface of the wire is scratched, thereby improving the slurry holding ability of the wire. As the slurry holding capacity of the wire improves, the amount of slurry supplied to the part where the wire and silicon ingot are in contact when slicing the silicon ingot can be increased, the slicing speed can be increased and the slicing time can be shortened. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a wire saw according to the present invention.
FIG. 2 is an enlarged sectional view showing a container containing hard particles in the wire saw according to the present invention.
FIG. 3 is an enlarged photograph showing a surface state of a wire before inserting a container in a wire saw according to the present invention.
FIG. 4 is an enlarged photograph showing a surface state of a wire after inserting a container in a wire saw according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Slurry nozzle 2 Slurry receptacle 3 Silicon ingot 4 Slice stand 5 Main roller 6 Wire 7 Dip tank 8 Wire supply reel 9 Container 11 with hard particles Hard particles

Claims (1)

In a wire saw that arranges a wire supplied from a supply reel between a plurality of interval holding rollers and winds it with a take-up reel, and slices a silicon ingot while supplying slurry between the plurality of interval holding rollers, By placing a container filled with one or more hard particles of silicon carbide, diamond and alumina on the supply reel side , and passing the wire through the container filled with the hard particles wire saw and supplying to said interval holding roller to the surface of the wire is roughened.

Images