JPS61182761A - Wafer take out method of wire saw - Google Patents

Abstract

PURPOSE:To prevent a cut surface from generating a flaw and/or a saw mark, by clamping a wafer train, after a workpiece to be cut finishes cutting, with separately provided take out arms further cutting a workpiece fixing bed again by a wire and taking out said wafer train. CONSTITUTION:A wire 2, cutting a work to be cut 4, bites at a work fixing bed 1. Next, a wafer train 4i is clamped in a manner being slightly lifted by separately provided, for instance, three wafer take out arms (3-1) (3-2). Next the wire 2 further cuts said fixing bed 1. In this way, if cutting of said fixing bed 1 is finished, the wafer train 4i, being lifted by once moving upward the take out arms (3-1) (3-2), is separated from said fixing bed 1. Subsequently, the wafer train 4i is drawn out to the outside of a wire saw by retracting said take out arms (3-1) (3-2). In this way, a wafer, being taken out without cleaning an abrasive grain or the like accumulated between the wafers after the work finishes cutting, is efficiently taken out with no generation of a saw mark and/or a flaw on the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for taking out a wafer, which is used in a wire saw that cuts, for example, a semiconductor material into thin wafers (hereinafter referred to as wafers) using a wire.

Conventional technology and its problems Conventionally, this cutting machine for cutting semiconductor materials, magnetic materials, ceramics, etc. has used a multi-thread wire stretched in parallel at predetermined intervals between a plurality of grooved rollers while pressing the wire against the object to be cut. It runs while injecting processing fluid containing abrasive grains into the cutting section to perform cutting, and has the function of cutting a large number of wafers of the same size from the same material.

The method for taking out the wafer with the above wire saw is as follows:
First, remove chips and a mixture of abrasive grains, oil, or water that are stuck in the cutting groove of the workpiece using a cleaning solution, and then pull up the wire to separate it from the workpiece, and then take out the workpiece fixing table. ing.

However, this method requires a lot of effort and time to clean and pull up the wire, resulting in poor work efficiency, and there are also problems in that scratches and saw marks appear on the cut surface when the wire is pulled up and separated from the object to be cut.

Purpose of the Invention This invention has been made to solve the above-mentioned problems of the prior art.
The purpose is to pick up wafers simply, quickly, and efficiently.

Structure of the Invention In the wafer take-out method according to the present invention, after cutting the object to be cut, the wafer row is gripped by a separate take-out arm, and the wafer row is again attached to the workpiece fixing table using a wire. cut,
It is characterized by taking out rows of wafers.

When cutting an object such as a semiconductor material with a wire saw, the object to be cut is fixed on an object fixing table with an adhesive, and the cutting is performed with a wire while raising the fixing table. At this time, since a machining fluid containing abrasive grains is injected into the cutting section, the abrasive grains and chips clog the cutting groove. Therefore, when removing the wire from the cutting groove after cutting, in the conventional method of passing the wire through the cutting groove, the wire rubs against the cut surface due to abrasive grains etc. stuck in the cutting groove, resulting in saw marks and flaws.

Therefore, in the present invention, after cutting the object to be cut, the object fixing table is cut in and each wafer is cut from the base and taken out.

The method of this invention will be explained below based on the drawings.

Figures 1 to 4 are explanatory diagrams showing the method of this invention, and Figure 1 shows a state in which the object to be cut (4) is cut and the wire (2) is inserted into the object fixing table (1). ■ Shows. Figure 2 shows the state in which the wafer row (41) is gripped by, for example, three separate wafer take-out arms (3-1) (3-2). At this time, the take-out arm grips the wafer row (41) slightly pushing it up. Next, the wire (2) is further cut into the object fixing table (1). FIG. 31 shows the state in the middle of cutting. When cutting the workpiece fixing base (1) horizontally, use the workpiece fixing base (1)
This is done by moving horizontally. When the incision cutting of the workpiece fixing table (1) is completed in this way, the state in the middle of taking out the wafer is shown in FIG.
-1') (3-2) is moved upward to lift the wafer row (4I) and pull it away from the object fixing table (1), and then the wafer take-out arm (3-1) (3-- 2
) and pull out the wafer row (41) out of the wire saw. The wafer row is then sent to the next cleaning step.

In addition, when separating the wafer row from the object fixing table, each wafer attachment may be broken and separated when the wall thickness at the root becomes thinner, without completely cutting the object fixing table. .

Next, a workpiece fixing table (
As shown in Fig. 5, the moving mechanism of 1) is a concave-convex fitting method on a slide base (1-4) fixed on a base (1-2) via a support (1-3). Attach a slidable base (1-5) to this base (1-5), and then attach a slidable base (1-6) to this base (1-5) using the concave-convex fitting method as described above, and place the object to be cut on this base. (4) The fixing base (1) is provided integrally. Then, on the bottom of the base table (1-5), there is a sphoid table (1-4).
A guide stand (
Attach 1-8) together with the pin (1-9), screw the pole screw (1-10) onto this guide stand, and drive this ball screw with the motor with reducer (1-11). How it works. (1-12) is a bolt for mounting the base (1-6), and (1-13) is a fixing bolt for the base (1-5).

That is, the moving mechanism moves the base (1-1) on the slide (1-4) by driving the motor (1-11).
-5), base (1-6) and object fixing table (1)
It is a mechanism that moves as one. Therefore, in the case of this mechanism, loosen the fixed pole (1-13) before starting the motor (
1-11) at a predetermined feed speed.
), the base (1-6) and the object fixing table (1) are moved by a predetermined amount to cut the object fixing table (1).

In addition, as shown in FIG. 6, an example of the wafer unloading device is a lifting motor (3-4') mounted on a cart (3-3').
A height-adjustable lifting platform (3-7) is installed with a lifting mechanism consisting of a ball screw C3-5> and a lifting arm (3-6), and one end is pivotally supported on the lifting table, and the other Guide rail (3-9) whose end is supported by Loadset A/(3-8)
) A U-shaped arm stand (3-10) that slides on the top is placed, and on this arm stand, for example, three arms consisting of one upper arm (3-1) and two lower arms (3-2) are placed. A wafer ejection arm is provided. The upper arm (3-1) is an arm stand (3-
The wafer mounted on the arm stand (3-10) can be mounted on the slide stand (3-11) attached to the arm stand (3-12) so as to be vertically swidable using the concave-convex fitting method. Grip with the gripping cylinder (3-13). The lower arm (3-2) is installed by penetrating the front wall of the arm stand (3-10>), and is attached to the arm stand advance/retreat cylinder (3
-14) is a mechanism that allows the wafer take-out arm to be extended and pulled out. In addition, the upper arm (3-
Soft rubber (3-15) is attached to each wafer contact surface of 1) and lower arm (3-2) to prevent damage to the wafer.
(3-16) is provided.

In other words, the wafer unloading device has an upper arm (3-1).
The lower arm ('3-2) has a function that can grip the wafer row all at once from K, and the load cell A/(3-8) confirms that the lower arm (3-2) is pressed against the wafer row and pushes up the wafer row. It has a function that maintains the appropriate force, a function that allows the cylinder for advancing and retracting the arm table (3-14) to follow or synchronize with the movement of the object fixing table moving mechanism, a function that allows the wafer row to be transferred to the next process while gripping it, etc. However, the wafer can be taken out efficiently.

Thermal theory: The moving mechanism for the object fixing table and the wafer take-out device shown here are merely examples, and the present invention is not limited thereto.

Effects of the Invention As explained above, according to the method of the present invention, a large number of wafers can be taken out without cleaning the abrasive particles accumulated between the wafers after cutting the object to be cut, which reduces the operating rate of the wire saw. Not only can the wafer be improved, but the wafer can be efficiently taken out without making saw marks or scratches, and is highly effective in cutting brittle materials.

[Brief explanation of the drawing]

Figures 1 to 4 are explanatory diagrams showing the method of this invention, in which Figure 1 shows a state in which the object to be cut has been cut and the wire is inserted into the object fixing table, and Figure 2 shows a row of wafers. FIG. 3 is a diagram showing the state in which the wafer is being held by the take-out arm, FIG. 3 is a diagram showing the state in which the cutting object fixing table is in the middle of cutting, FIG. 4 is a diagram showing the state in the middle of taking out a row of wafers, and FIG. FIG. 6 is a longitudinal cross-sectional view showing an example of a mechanism for moving the object fixing table for carrying out the method of the present invention, and FIG.
It is a front view. 1... Cutting object fixing stand, 2... Wire, 3-1
゜3-2...Wafer take-out arm, 4...Object to be cut, 41...Wafer row.

Claims (1)

[Claims] In a wire saw that cuts the workpiece by pressing the workpiece against the wire and running it while supplying a machining liquid containing abrasive grains, after cutting the workpiece, the wafer row is held by a separate take-out arm. A method for taking out wafers from a wire saw, which is characterized in that the fixing table of the object to be cut is cut again with a wire and a row of wafers is taken out.