JPH0526338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a cutting technique, and particularly to a technique that is effective when applied to cutting a semiconductor wafer into a dice shape.

[Background technology]

2. Description of the Related Art Generally, in the manufacture of semiconductor devices, a silicon wafer having a large number of elements formed on its surface is cut into a dice shape with a side of several millimeters using a rotating blade. At the time of this cutting, as stated in Publication of Practical Application No. 114682/1982,
A cooling liquid such as water is sprayed at the cutting position of the blade, and a liquid for removing cutting debris is sprayed onto the wafer surface.

However, the present inventor discovered that although the wafer surface is cleaned with a liquid for removing cutting debris during cutting, the passivation film on the wafer surface and the bonding electrode (pad) on which the passivation film is not formed. It was discovered that silicon cutting debris was attached to the parts. The inventor of the present invention investigated the cause of this problem and found that the rotation of the blade causes cooling water mixed with cutting debris and water for removing cutting debris to be blown up into the cover provided around the blade, resulting in the cutting It was discovered that water contaminated with debris was slammed onto the wafer surface by the rotational force of the blade. We have also discovered that as the contaminated water is slammed against the wafer surface, silicon cutting debris in the contaminated water firmly adheres to the passivation film, electrodes, etc., and cannot be removed by simply spouting a cleaning solution onto the wafer surface. Furthermore, the present inventor has found that the aforementioned cutting debris causes cracks in the passivation film, defective wire bonding to the electrodes, and the like. Therefore, the inventors of the present invention have made extensive studies to solve various problems that occur when water (liquid) containing cutting waste is thrown onto a workpiece.

[Purpose of the invention]

An object of the present invention is to provide a technique that can reduce deterioration of the surface of a workpiece that occurs when the workpiece is cut.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, by making the cover around the blade have a structure that prevents the water used during cutting from getting caught up in it, or a structure that allows the water to be discharged even if it does get caught up, cutting debris taken in with water can be prevented from being exposed to the rotation of the blade. Since it is possible to prevent the surface of the cut object from being struck, deterioration of the surface of the cut object can be prevented.

Embodiment 1 Fig. 1 is an overall configuration diagram of a dicing device which is an embodiment of the present invention, Fig. 2 is a front view of main parts of a dicing device which is an embodiment of the present invention, and Fig. 3 is a diagram showing the main parts of a dicing device which is an embodiment of the present invention. FIG. 1 is a side view of main parts of a dicing apparatus according to an embodiment.

As shown in FIG. 1, the dicing apparatus 20 is roughly divided into a loader section 21 that is a wafer supply section, an unloader section 22 that stores the wafer after dicing, a dicing section 23 that cuts the wafer into dice, and a dicing section 21 that is a wafer supply section. It is comprised of an alignment section 24 that positions the wafer in order to accurately cut the wafer at 23, a spinner section 25 that rotates and dries the wafer, and the like. Next, the dicing section 23 will be explained in detail using FIGS. 2 and 3. 26 is an object to be cut, such as a semiconductor wafer 2;
A blade 7 cuts the blade into a die shape, and a flange 28 holds the blade 26 from both sides. These blades 26 and flanges 28 are connected to a rotating shaft 30 of a spindle 29, and are configured to rotate at an arbitrary speed, for example, 30,000 rpm. A cover 31 is attached to the spindle 29 and surrounds the blade 26 to prevent danger. A portion of the cover 31 that faces the rotational direction of the blade 26 (hereinafter referred to as a side portion) is comprised of an outer wall 32 and an inner wall 33 having an arc-shaped side cross section as shown in FIG.
A hollow portion 34 having a double structure and an opening 40 is formed. The inner wall 33 has a cavity 3
A plurality of water drain ports 35 are provided which communicate with the blade 26, and the direction of the ports is oriented in a direction in which the water rolled up when the blade 26 rotates is scattered by centrifugal force, that is, in a direction that substantially coincides with the tangential direction. . 36
is a notch formed on the side of the cover 31 in the direction in which the blade 26 stirs up water. The notch width H is set so that the end of the notch portion 36 is at the same height as or higher than the rotation center of the rotating shaft 30. As a result, the cover 31 and the wafer 2
This produces an extremely large effect of discharging the rolled up water that cannot be achieved with a small gap between the two. 3
7 is a cooling nozzle that spouts a liquid, such as pure water, for cooling the blade 26 so that the blade 26 is not damaged by the heat generated when cutting the wafer 27; 38 is a waste generated when cutting the wafer 27; This is a cleaning nozzle for washing away.
Note that 39 is a wafer mounting table that can hold and fix the wafer 27 by vacuum suction.

Next, the operation of this embodiment will be explained. The wafer 27 conveyed by the belt from the loader section 21 is placed on a wafer mounting table 39 waiting in the alignment section 24.
A suction arm (not shown) suctions, conveys, and places the image on the screen. The wafer 27 is connected to the alignment section 24
After the wafer is positioned to enable accurate dicing, the wafer is moved to the dicing section 23 together with the wafer mounting table 39. When the wafer 27 is transferred to the dicing section 23, the blade 26 begins to rotate by the rotating shaft 30 of the spindle 29. Thereafter, the blade 26 descends and cuts the wafer 27 while moving in a direction perpendicular to the axial direction of the rotary shaft 30 to perform dicing. During this dicing, water is used to cool the blade 26 and to clean the wafer 27 surface so that cutting debris does not adhere to the surface of the wafer 27.
A large amount of cutting debris (tiny silicon pieces) is mixed into the water on the surface. The dirty water W containing such cutting waste is rolled up by the high speed rotation of the blade 26 and the flange 28. However, since the notch 36 is formed so that its end is located at a higher position than the rotating shaft 30, most of the wastewater W is discharged through the notch 36 at the initial stage of sewage entrainment, and a large amount sewage W is covered 3
This prevents it from entering the inside. This is because the amount of dirty water W that is rolled up above the rotating shaft 30 by the rotation of the blade 26 is small, so the notch 3 is arranged so that the end is higher than the rotating shaft.
6, the waste water W can be efficiently discharged. Furthermore, a small amount of waste water W that has not been discharged through the notch 36 but has been drawn into the cover 31 is also collected by the outer wall 32 and the inner wall 33 through the plurality of drain ports 35 arranged in the tangential direction of the blade 26. The waste water W enters the cavity 34 and is almost completely discharged to the outside of the cover 31.

Therefore, it is possible to almost completely prevent the problem of the dirty water W caught in the cover 31 being thrown onto the wafer 27.

Embodiment 2 FIG. 4 shows the main parts of a dicing apparatus which is one of the embodiments of the present invention. The difference between this embodiment and Embodiment 1 is the structure of the cover, and in FIG. 4, the same components as in Embodiment 1 are denoted by the same reference numerals, and the explanation thereof will be omitted. 32a is the outer wall of the cover 31a of the blade 26 and has an inverted triangular cross section as shown in the figure. Reference numeral 33a denotes an inner wall of the cover 31a, which has a key-shaped cross section and forms a flow path for the waste water W. 34a
is a cavity formed by an outer wall 32a and an inner wall 33a, and communicates with the blade 26 side through a water drain port 35a. By having such a configuration,
cover 31 when cutting a wafer (not shown).
The sewage W caught in the inside a jumps into the cavity 34a through the drain port 33a and hits the outer wall 32a. By the way, since the outer wall 32a has an inverted triangular cross section as shown in the figure, the sewage W flows through the cover 31.
It bounces back toward the side surface of point a and is discharged along the flow path of the cavity 34a formed by the inner wall 33a. In addition, in this embodiment as well, a notch is provided in the cover 31a as in the first embodiment.

Embodiment 3 FIG. 5 is a perspective view of the main parts of a dicing apparatus which is an embodiment of the present invention, and FIG. 6 is a sectional view taken along the line A--A in FIG. In this embodiment as well, the same components as those in the first embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted. In FIG. 5, 31b is the blade 2
In the cover No. 6, a notch 36b is formed in the side of the cover 31b in the direction in which the rotation is upward when viewed from below the blade 26, and the notch 36b is formed in the side of the cover 31b in the direction in which the rotation is directed upward when viewed from below the blade 26, and the rotation is downward when viewed from the opposite side, that is, from below the blade 26. An opening 40 is provided on the side of the cover 31b in the direction. The opening 40 is located between the inner wall 33b and the outer wall 3.
2b, and a flat buffer plate 41 extends in two at the bottom thereof, and the peripheral portion of the blade 26 fits between the two bifurcated buffer plates 41. It is provided close to the buffer plate 41 as shown in FIG.

Next, the operation of this embodiment will be explained. The rotating shaft 30 of the spindle 29 is rotated, and the rotating shaft 3
0 is rotated at high speed. At this time, cooling water is sprayed onto the blade 26 and cleaning water is sprayed onto the wafer, and a large amount of cutting debris will be mixed into the water stagnant on the wafer surface. Therefore, a large amount of contaminated water mixed with cutting debris is stirred up by the rotation of the blade 26, but in the initial stage of stirring up the contaminated water, the width of the notch is smaller than the height of the rotating shaft 30. It is discharged from the notch 36b, which is formed to have a longer length. The cutout portion 36b
Some of the polluted water that could not be discharged is removed from the cover 31b.
A cavity 3 formed by an inner wall 33b and an outer wall 32b of
4b and reaches the opening 40 and flows down. The contaminated water that flows down hits the buffer plate 41 and does not directly hit the wafer surface. Further, the contaminated water that has not entered the cavity 34b is scattered toward the wafer by the rotation of the blade 26, but the buffer plate 41 is provided so as to penetrate through the outer wall 32b and the inner wall 33b and extend to the periphery of the blade 26. Therefore, the scattered contaminated water first hits the buffer plate 41 and does not directly collide with the wafer surface.

〔effect〕

(1) At least the cover that faces the direction of rotation of the blade has a double structure of an outer wall, a cavity, and an inner wall, and the inner wall is provided with a water drain port that communicates with the cavity, so that water can be drawn in by the rotation of the blade. Since the water containing cutting waste (dirty water) can be drained through the water drain port, the surface of the workpiece is prevented from directly hitting the surface of the workpiece with the rotational force of the blade, thereby preventing deterioration of the surface of the workpiece. can do.

(2) By oriented the water drain opening in (1) in the tangential direction of the blade, water containing entangled cutting debris can be efficiently discharged to the cavity, allowing more complete cleaning of the surface of the workpiece. It becomes possible to prevent deterioration.

(3) By providing a notch cut out to a position higher than the center of rotation of the blade on the side of the cover that faces the direction of rotation of the blade and whose rotation is directed upward, at the beginning of the rotation of the blade,
Since most of the cutting water can be drained without being drawn into the cover, the amount of cutting waste that hits the surface of the workpiece can be reduced, and deterioration of the surface of the workpiece can be effectively prevented.

(4) By providing a flat buffer plate extending in two on the cover on the side that faces the direction of rotation of the blade and whose rotation is downward, polluted water retains the rotational force of the blade. Since contact with the surface of the workpiece can be prevented, deterioration of the surface of the workpiece can be easily prevented.

(5) By providing an opening above the buffer plate mentioned in (4) that penetrates through the inner and outer walls, contaminated water can be efficiently discharged outside the cover, so it will not interfere with the rotation of the blade. .

Although the invention made by the present inventor has been specifically explained based on the examples above, the present invention is not limited to the above examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say. For example, the present invention is not limited to the shapes of the inner and outer walls, the number and shape of drain ports, and the shape of the buffer plate.

Further, even if a part of the cover is formed into a mesh shape, polluted water can be effectively discharged.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to wafer cutting technology, which is the background field of application, but the invention is not limited to this. It can be applied to cutting any article that must be prevented from deteriorating.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a dicing apparatus according to an embodiment of the present invention, Fig. 2 is a partial front sectional view of the main parts of the dicing apparatus shown in Fig. 1, and Fig. 3 is a dicing apparatus shown in Fig. 1. Partial cross-sectional side view of main parts of
FIG. 4 is a partial sectional view of the main parts of a dicing apparatus which is an embodiment of the present invention, FIG. 5 is a perspective view of the main parts of a dicing apparatus which is an embodiment of the invention, and FIG.
This figure is a partial cross-sectional plan view of the main part of the dicing apparatus shown in FIG. 5. 20...Dicing device, 21...Loader section,
22... Unloader section, 23... Dicing section,
24... Alignment section, 25... Spinner section,
26... Blade, 27... Wafer, 28... Flange, 29... Spindle, 30... Rotating shaft,
31, 31a, 31b...Cover, 32, 32
a, 32b...outer wall, 33, 33a, 33b...
Inner wall, 34, 34a, 34b...Cavity part, 35,
35a, 35b... Water drain port, 36, 36a, 3
6b... Notch, 37... Cooling nozzle, 38
... Cleaning nozzle, 39 ... Wafer mounting table, 40
...Opening, 41...Buffer plate.

Claims (1)

[Scope of Claims] 1. A dicing device comprising: a blade that cuts a workpiece while rotating; a cover provided around the blade; and a nozzle provided near the blade capable of spouting liquid; The cover facing the rotation direction is an outer wall,
A cavity is formed by a double structure with an inner wall provided with a water drain port, and the cavity is formed as a flow path to an opening provided in the cover, facing the rotation direction of the blade, and rotating. A notch is provided on the side facing upward, the end of the notch is formed at a height higher than the rotation center of the blade, and is opposite to the rotational direction of the blade, and on the side where the rotation is downward. ,
A dicing device characterized by being provided with a buffer plate that extends from the cover in the direction of the blade. 2. Claims characterized in that the direction of the water drain port is arranged so as to substantially match the direction in which water drawn into the cover by the rotation of the blade is scattered by the centrifugal force of the blade. The dicing device according to item 1.